Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 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

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/sysctl.h>
 38 #include <linux/seq_file.h>
 39 #include <linux/fs.h>
 40 #include <linux/poll.h>
 41 #include <linux/ctype.h>
 42 #include <linux/string.h>
 43 #include <linux/hdreg.h>
 44 #include <linux/proc_fs.h>
 45 #include <linux/random.h>
 46 #include <linux/module.h>
 47 #include <linux/reboot.h>
 48 #include <linux/file.h>
 49 #include <linux/compat.h>
 50 #include <linux/delay.h>
 51 #include <linux/raid/md_p.h>
 52 #include <linux/raid/md_u.h>
 53 #include <linux/slab.h>
 54 #include "md.h"
 55 #include "bitmap.h"
 56 #include "md-cluster.h"
 57 
 58 #ifndef MODULE
 59 static void autostart_arrays(int part);
 60 #endif
 61 
 62 /* pers_list is a list of registered personalities protected
 63  * by pers_lock.
 64  * pers_lock does extra service to protect accesses to
 65  * mddev->thread when the mutex cannot be held.
 66  */
 67 static LIST_HEAD(pers_list);
 68 static DEFINE_SPINLOCK(pers_lock);
 69 
 70 struct md_cluster_operations *md_cluster_ops;
 71 EXPORT_SYMBOL(md_cluster_ops);
 72 struct module *md_cluster_mod;
 73 EXPORT_SYMBOL(md_cluster_mod);
 74 
 75 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 76 static struct workqueue_struct *md_wq;
 77 static struct workqueue_struct *md_misc_wq;
 78 
 79 static int remove_and_add_spares(struct mddev *mddev,
 80                                  struct md_rdev *this);
 81 static void mddev_detach(struct mddev *mddev);
 82 
 83 /*
 84  * Default number of read corrections we'll attempt on an rdev
 85  * before ejecting it from the array. We divide the read error
 86  * count by 2 for every hour elapsed between read errors.
 87  */
 88 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
 89 /*
 90  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 91  * is 1000 KB/sec, so the extra system load does not show up that much.
 92  * Increase it if you want to have more _guaranteed_ speed. Note that
 93  * the RAID driver will use the maximum available bandwidth if the IO
 94  * subsystem is idle. There is also an 'absolute maximum' reconstruction
 95  * speed limit - in case reconstruction slows down your system despite
 96  * idle IO detection.
 97  *
 98  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
 99  * or /sys/block/mdX/md/sync_speed_{min,max}
100  */
101 
102 static int sysctl_speed_limit_min = 1000;
103 static int sysctl_speed_limit_max = 200000;
104 static inline int speed_min(struct mddev *mddev)
105 {
106         return mddev->sync_speed_min ?
107                 mddev->sync_speed_min : sysctl_speed_limit_min;
108 }
109 
110 static inline int speed_max(struct mddev *mddev)
111 {
112         return mddev->sync_speed_max ?
113                 mddev->sync_speed_max : sysctl_speed_limit_max;
114 }
115 
116 static struct ctl_table_header *raid_table_header;
117 
118 static struct ctl_table raid_table[] = {
119         {
120                 .procname       = "speed_limit_min",
121                 .data           = &sysctl_speed_limit_min,
122                 .maxlen         = sizeof(int),
123                 .mode           = S_IRUGO|S_IWUSR,
124                 .proc_handler   = proc_dointvec,
125         },
126         {
127                 .procname       = "speed_limit_max",
128                 .data           = &sysctl_speed_limit_max,
129                 .maxlen         = sizeof(int),
130                 .mode           = S_IRUGO|S_IWUSR,
131                 .proc_handler   = proc_dointvec,
132         },
133         { }
134 };
135 
136 static struct ctl_table raid_dir_table[] = {
137         {
138                 .procname       = "raid",
139                 .maxlen         = 0,
140                 .mode           = S_IRUGO|S_IXUGO,
141                 .child          = raid_table,
142         },
143         { }
144 };
145 
146 static struct ctl_table raid_root_table[] = {
147         {
148                 .procname       = "dev",
149                 .maxlen         = 0,
150                 .mode           = 0555,
151                 .child          = raid_dir_table,
152         },
153         {  }
154 };
155 
156 static const struct block_device_operations md_fops;
157 
158 static int start_readonly;
159 
160 /* bio_clone_mddev
161  * like bio_clone, but with a local bio set
162  */
163 
164 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
165                             struct mddev *mddev)
166 {
167         struct bio *b;
168 
169         if (!mddev || !mddev->bio_set)
170                 return bio_alloc(gfp_mask, nr_iovecs);
171 
172         b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
173         if (!b)
174                 return NULL;
175         return b;
176 }
177 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
178 
179 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
180                             struct mddev *mddev)
181 {
182         if (!mddev || !mddev->bio_set)
183                 return bio_clone(bio, gfp_mask);
184 
185         return bio_clone_bioset(bio, gfp_mask, mddev->bio_set);
186 }
187 EXPORT_SYMBOL_GPL(bio_clone_mddev);
188 
189 /*
190  * We have a system wide 'event count' that is incremented
191  * on any 'interesting' event, and readers of /proc/mdstat
192  * can use 'poll' or 'select' to find out when the event
193  * count increases.
194  *
195  * Events are:
196  *  start array, stop array, error, add device, remove device,
197  *  start build, activate spare
198  */
199 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
200 static atomic_t md_event_count;
201 void md_new_event(struct mddev *mddev)
202 {
203         atomic_inc(&md_event_count);
204         wake_up(&md_event_waiters);
205 }
206 EXPORT_SYMBOL_GPL(md_new_event);
207 
208 /* Alternate version that can be called from interrupts
209  * when calling sysfs_notify isn't needed.
210  */
211 static void md_new_event_inintr(struct mddev *mddev)
212 {
213         atomic_inc(&md_event_count);
214         wake_up(&md_event_waiters);
215 }
216 
217 /*
218  * Enables to iterate over all existing md arrays
219  * all_mddevs_lock protects this list.
220  */
221 static LIST_HEAD(all_mddevs);
222 static DEFINE_SPINLOCK(all_mddevs_lock);
223 
224 /*
225  * iterates through all used mddevs in the system.
226  * We take care to grab the all_mddevs_lock whenever navigating
227  * the list, and to always hold a refcount when unlocked.
228  * Any code which breaks out of this loop while own
229  * a reference to the current mddev and must mddev_put it.
230  */
231 #define for_each_mddev(_mddev,_tmp)                                     \
232                                                                         \
233         for (({ spin_lock(&all_mddevs_lock);                            \
234                 _tmp = all_mddevs.next;                                 \
235                 _mddev = NULL;});                                       \
236              ({ if (_tmp != &all_mddevs)                                \
237                         mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
238                 spin_unlock(&all_mddevs_lock);                          \
239                 if (_mddev) mddev_put(_mddev);                          \
240                 _mddev = list_entry(_tmp, struct mddev, all_mddevs);    \
241                 _tmp != &all_mddevs;});                                 \
242              ({ spin_lock(&all_mddevs_lock);                            \
243                 _tmp = _tmp->next;})                                    \
244                 )
245 
246 /* Rather than calling directly into the personality make_request function,
247  * IO requests come here first so that we can check if the device is
248  * being suspended pending a reconfiguration.
249  * We hold a refcount over the call to ->make_request.  By the time that
250  * call has finished, the bio has been linked into some internal structure
251  * and so is visible to ->quiesce(), so we don't need the refcount any more.
252  */
253 static void md_make_request(struct request_queue *q, struct bio *bio)
254 {
255         const int rw = bio_data_dir(bio);
256         struct mddev *mddev = q->queuedata;
257         unsigned int sectors;
258         int cpu;
259 
260         if (mddev == NULL || mddev->pers == NULL
261             || !mddev->ready) {
262                 bio_io_error(bio);
263                 return;
264         }
265         if (mddev->ro == 1 && unlikely(rw == WRITE)) {
266                 bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
267                 return;
268         }
269         smp_rmb(); /* Ensure implications of  'active' are visible */
270         rcu_read_lock();
271         if (mddev->suspended) {
272                 DEFINE_WAIT(__wait);
273                 for (;;) {
274                         prepare_to_wait(&mddev->sb_wait, &__wait,
275                                         TASK_UNINTERRUPTIBLE);
276                         if (!mddev->suspended)
277                                 break;
278                         rcu_read_unlock();
279                         schedule();
280                         rcu_read_lock();
281                 }
282                 finish_wait(&mddev->sb_wait, &__wait);
283         }
284         atomic_inc(&mddev->active_io);
285         rcu_read_unlock();
286 
287         /*
288          * save the sectors now since our bio can
289          * go away inside make_request
290          */
291         sectors = bio_sectors(bio);
292         mddev->pers->make_request(mddev, bio);
293 
294         cpu = part_stat_lock();
295         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
296         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
297         part_stat_unlock();
298 
299         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
300                 wake_up(&mddev->sb_wait);
301 }
302 
303 /* mddev_suspend makes sure no new requests are submitted
304  * to the device, and that any requests that have been submitted
305  * are completely handled.
306  * Once mddev_detach() is called and completes, the module will be
307  * completely unused.
308  */
309 void mddev_suspend(struct mddev *mddev)
310 {
311         BUG_ON(mddev->suspended);
312         mddev->suspended = 1;
313         synchronize_rcu();
314         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
315         mddev->pers->quiesce(mddev, 1);
316 
317         del_timer_sync(&mddev->safemode_timer);
318 }
319 EXPORT_SYMBOL_GPL(mddev_suspend);
320 
321 void mddev_resume(struct mddev *mddev)
322 {
323         mddev->suspended = 0;
324         wake_up(&mddev->sb_wait);
325         mddev->pers->quiesce(mddev, 0);
326 
327         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
328         md_wakeup_thread(mddev->thread);
329         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
330 }
331 EXPORT_SYMBOL_GPL(mddev_resume);
332 
333 int mddev_congested(struct mddev *mddev, int bits)
334 {
335         struct md_personality *pers = mddev->pers;
336         int ret = 0;
337 
338         rcu_read_lock();
339         if (mddev->suspended)
340                 ret = 1;
341         else if (pers && pers->congested)
342                 ret = pers->congested(mddev, bits);
343         rcu_read_unlock();
344         return ret;
345 }
346 EXPORT_SYMBOL_GPL(mddev_congested);
347 static int md_congested(void *data, int bits)
348 {
349         struct mddev *mddev = data;
350         return mddev_congested(mddev, bits);
351 }
352 
353 static int md_mergeable_bvec(struct request_queue *q,
354                              struct bvec_merge_data *bvm,
355                              struct bio_vec *biovec)
356 {
357         struct mddev *mddev = q->queuedata;
358         int ret;
359         rcu_read_lock();
360         if (mddev->suspended) {
361                 /* Must always allow one vec */
362                 if (bvm->bi_size == 0)
363                         ret = biovec->bv_len;
364                 else
365                         ret = 0;
366         } else {
367                 struct md_personality *pers = mddev->pers;
368                 if (pers && pers->mergeable_bvec)
369                         ret = pers->mergeable_bvec(mddev, bvm, biovec);
370                 else
371                         ret = biovec->bv_len;
372         }
373         rcu_read_unlock();
374         return ret;
375 }
376 /*
377  * Generic flush handling for md
378  */
379 
380 static void md_end_flush(struct bio *bio, int err)
381 {
382         struct md_rdev *rdev = bio->bi_private;
383         struct mddev *mddev = rdev->mddev;
384 
385         rdev_dec_pending(rdev, mddev);
386 
387         if (atomic_dec_and_test(&mddev->flush_pending)) {
388                 /* The pre-request flush has finished */
389                 queue_work(md_wq, &mddev->flush_work);
390         }
391         bio_put(bio);
392 }
393 
394 static void md_submit_flush_data(struct work_struct *ws);
395 
396 static void submit_flushes(struct work_struct *ws)
397 {
398         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
399         struct md_rdev *rdev;
400 
401         INIT_WORK(&mddev->flush_work, md_submit_flush_data);
402         atomic_set(&mddev->flush_pending, 1);
403         rcu_read_lock();
404         rdev_for_each_rcu(rdev, mddev)
405                 if (rdev->raid_disk >= 0 &&
406                     !test_bit(Faulty, &rdev->flags)) {
407                         /* Take two references, one is dropped
408                          * when request finishes, one after
409                          * we reclaim rcu_read_lock
410                          */
411                         struct bio *bi;
412                         atomic_inc(&rdev->nr_pending);
413                         atomic_inc(&rdev->nr_pending);
414                         rcu_read_unlock();
415                         bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
416                         bi->bi_end_io = md_end_flush;
417                         bi->bi_private = rdev;
418                         bi->bi_bdev = rdev->bdev;
419                         atomic_inc(&mddev->flush_pending);
420                         submit_bio(WRITE_FLUSH, bi);
421                         rcu_read_lock();
422                         rdev_dec_pending(rdev, mddev);
423                 }
424         rcu_read_unlock();
425         if (atomic_dec_and_test(&mddev->flush_pending))
426                 queue_work(md_wq, &mddev->flush_work);
427 }
428 
429 static void md_submit_flush_data(struct work_struct *ws)
430 {
431         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
432         struct bio *bio = mddev->flush_bio;
433 
434         if (bio->bi_iter.bi_size == 0)
435                 /* an empty barrier - all done */
436                 bio_endio(bio, 0);
437         else {
438                 bio->bi_rw &= ~REQ_FLUSH;
439                 mddev->pers->make_request(mddev, bio);
440         }
441 
442         mddev->flush_bio = NULL;
443         wake_up(&mddev->sb_wait);
444 }
445 
446 void md_flush_request(struct mddev *mddev, struct bio *bio)
447 {
448         spin_lock_irq(&mddev->lock);
449         wait_event_lock_irq(mddev->sb_wait,
450                             !mddev->flush_bio,
451                             mddev->lock);
452         mddev->flush_bio = bio;
453         spin_unlock_irq(&mddev->lock);
454 
455         INIT_WORK(&mddev->flush_work, submit_flushes);
456         queue_work(md_wq, &mddev->flush_work);
457 }
458 EXPORT_SYMBOL(md_flush_request);
459 
460 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
461 {
462         struct mddev *mddev = cb->data;
463         md_wakeup_thread(mddev->thread);
464         kfree(cb);
465 }
466 EXPORT_SYMBOL(md_unplug);
467 
468 static inline struct mddev *mddev_get(struct mddev *mddev)
469 {
470         atomic_inc(&mddev->active);
471         return mddev;
472 }
473 
474 static void mddev_delayed_delete(struct work_struct *ws);
475 
476 static void mddev_put(struct mddev *mddev)
477 {
478         struct bio_set *bs = NULL;
479 
480         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
481                 return;
482         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
483             mddev->ctime == 0 && !mddev->hold_active) {
484                 /* Array is not configured at all, and not held active,
485                  * so destroy it */
486                 list_del_init(&mddev->all_mddevs);
487                 bs = mddev->bio_set;
488                 mddev->bio_set = NULL;
489                 if (mddev->gendisk) {
490                         /* We did a probe so need to clean up.  Call
491                          * queue_work inside the spinlock so that
492                          * flush_workqueue() after mddev_find will
493                          * succeed in waiting for the work to be done.
494                          */
495                         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
496                         queue_work(md_misc_wq, &mddev->del_work);
497                 } else
498                         kfree(mddev);
499         }
500         spin_unlock(&all_mddevs_lock);
501         if (bs)
502                 bioset_free(bs);
503 }
504 
505 void mddev_init(struct mddev *mddev)
506 {
507         mutex_init(&mddev->open_mutex);
508         mutex_init(&mddev->reconfig_mutex);
509         mutex_init(&mddev->bitmap_info.mutex);
510         INIT_LIST_HEAD(&mddev->disks);
511         INIT_LIST_HEAD(&mddev->all_mddevs);
512         init_timer(&mddev->safemode_timer);
513         atomic_set(&mddev->active, 1);
514         atomic_set(&mddev->openers, 0);
515         atomic_set(&mddev->active_io, 0);
516         spin_lock_init(&mddev->lock);
517         atomic_set(&mddev->flush_pending, 0);
518         init_waitqueue_head(&mddev->sb_wait);
519         init_waitqueue_head(&mddev->recovery_wait);
520         mddev->reshape_position = MaxSector;
521         mddev->reshape_backwards = 0;
522         mddev->last_sync_action = "none";
523         mddev->resync_min = 0;
524         mddev->resync_max = MaxSector;
525         mddev->level = LEVEL_NONE;
526 }
527 EXPORT_SYMBOL_GPL(mddev_init);
528 
529 static struct mddev *mddev_find(dev_t unit)
530 {
531         struct mddev *mddev, *new = NULL;
532 
533         if (unit && MAJOR(unit) != MD_MAJOR)
534                 unit &= ~((1<<MdpMinorShift)-1);
535 
536  retry:
537         spin_lock(&all_mddevs_lock);
538 
539         if (unit) {
540                 list_for_each_entry(mddev, &all_mddevs, all_mddevs)
541                         if (mddev->unit == unit) {
542                                 mddev_get(mddev);
543                                 spin_unlock(&all_mddevs_lock);
544                                 kfree(new);
545                                 return mddev;
546                         }
547 
548                 if (new) {
549                         list_add(&new->all_mddevs, &all_mddevs);
550                         spin_unlock(&all_mddevs_lock);
551                         new->hold_active = UNTIL_IOCTL;
552                         return new;
553                 }
554         } else if (new) {
555                 /* find an unused unit number */
556                 static int next_minor = 512;
557                 int start = next_minor;
558                 int is_free = 0;
559                 int dev = 0;
560                 while (!is_free) {
561                         dev = MKDEV(MD_MAJOR, next_minor);
562                         next_minor++;
563                         if (next_minor > MINORMASK)
564                                 next_minor = 0;
565                         if (next_minor == start) {
566                                 /* Oh dear, all in use. */
567                                 spin_unlock(&all_mddevs_lock);
568                                 kfree(new);
569                                 return NULL;
570                         }
571 
572                         is_free = 1;
573                         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
574                                 if (mddev->unit == dev) {
575                                         is_free = 0;
576                                         break;
577                                 }
578                 }
579                 new->unit = dev;
580                 new->md_minor = MINOR(dev);
581                 new->hold_active = UNTIL_STOP;
582                 list_add(&new->all_mddevs, &all_mddevs);
583                 spin_unlock(&all_mddevs_lock);
584                 return new;
585         }
586         spin_unlock(&all_mddevs_lock);
587 
588         new = kzalloc(sizeof(*new), GFP_KERNEL);
589         if (!new)
590                 return NULL;
591 
592         new->unit = unit;
593         if (MAJOR(unit) == MD_MAJOR)
594                 new->md_minor = MINOR(unit);
595         else
596                 new->md_minor = MINOR(unit) >> MdpMinorShift;
597 
598         mddev_init(new);
599 
600         goto retry;
601 }
602 
603 static struct attribute_group md_redundancy_group;
604 
605 void mddev_unlock(struct mddev *mddev)
606 {
607         if (mddev->to_remove) {
608                 /* These cannot be removed under reconfig_mutex as
609                  * an access to the files will try to take reconfig_mutex
610                  * while holding the file unremovable, which leads to
611                  * a deadlock.
612                  * So hold set sysfs_active while the remove in happeing,
613                  * and anything else which might set ->to_remove or my
614                  * otherwise change the sysfs namespace will fail with
615                  * -EBUSY if sysfs_active is still set.
616                  * We set sysfs_active under reconfig_mutex and elsewhere
617                  * test it under the same mutex to ensure its correct value
618                  * is seen.
619                  */
620                 struct attribute_group *to_remove = mddev->to_remove;
621                 mddev->to_remove = NULL;
622                 mddev->sysfs_active = 1;
623                 mutex_unlock(&mddev->reconfig_mutex);
624 
625                 if (mddev->kobj.sd) {
626                         if (to_remove != &md_redundancy_group)
627                                 sysfs_remove_group(&mddev->kobj, to_remove);
628                         if (mddev->pers == NULL ||
629                             mddev->pers->sync_request == NULL) {
630                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
631                                 if (mddev->sysfs_action)
632                                         sysfs_put(mddev->sysfs_action);
633                                 mddev->sysfs_action = NULL;
634                         }
635                 }
636                 mddev->sysfs_active = 0;
637         } else
638                 mutex_unlock(&mddev->reconfig_mutex);
639 
640         /* As we've dropped the mutex we need a spinlock to
641          * make sure the thread doesn't disappear
642          */
643         spin_lock(&pers_lock);
644         md_wakeup_thread(mddev->thread);
645         spin_unlock(&pers_lock);
646 }
647 EXPORT_SYMBOL_GPL(mddev_unlock);
648 
649 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
650 {
651         struct md_rdev *rdev;
652 
653         rdev_for_each_rcu(rdev, mddev)
654                 if (rdev->desc_nr == nr)
655                         return rdev;
656 
657         return NULL;
658 }
659 EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
660 
661 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
662 {
663         struct md_rdev *rdev;
664 
665         rdev_for_each(rdev, mddev)
666                 if (rdev->bdev->bd_dev == dev)
667                         return rdev;
668 
669         return NULL;
670 }
671 
672 static struct md_rdev *find_rdev_rcu(struct mddev *mddev, dev_t dev)
673 {
674         struct md_rdev *rdev;
675 
676         rdev_for_each_rcu(rdev, mddev)
677                 if (rdev->bdev->bd_dev == dev)
678                         return rdev;
679 
680         return NULL;
681 }
682 
683 static struct md_personality *find_pers(int level, char *clevel)
684 {
685         struct md_personality *pers;
686         list_for_each_entry(pers, &pers_list, list) {
687                 if (level != LEVEL_NONE && pers->level == level)
688                         return pers;
689                 if (strcmp(pers->name, clevel)==0)
690                         return pers;
691         }
692         return NULL;
693 }
694 
695 /* return the offset of the super block in 512byte sectors */
696 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
697 {
698         sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
699         return MD_NEW_SIZE_SECTORS(num_sectors);
700 }
701 
702 static int alloc_disk_sb(struct md_rdev *rdev)
703 {
704         rdev->sb_page = alloc_page(GFP_KERNEL);
705         if (!rdev->sb_page) {
706                 printk(KERN_ALERT "md: out of memory.\n");
707                 return -ENOMEM;
708         }
709 
710         return 0;
711 }
712 
713 void md_rdev_clear(struct md_rdev *rdev)
714 {
715         if (rdev->sb_page) {
716                 put_page(rdev->sb_page);
717                 rdev->sb_loaded = 0;
718                 rdev->sb_page = NULL;
719                 rdev->sb_start = 0;
720                 rdev->sectors = 0;
721         }
722         if (rdev->bb_page) {
723                 put_page(rdev->bb_page);
724                 rdev->bb_page = NULL;
725         }
726         kfree(rdev->badblocks.page);
727         rdev->badblocks.page = NULL;
728 }
729 EXPORT_SYMBOL_GPL(md_rdev_clear);
730 
731 static void super_written(struct bio *bio, int error)
732 {
733         struct md_rdev *rdev = bio->bi_private;
734         struct mddev *mddev = rdev->mddev;
735 
736         if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
737                 printk("md: super_written gets error=%d, uptodate=%d\n",
738                        error, test_bit(BIO_UPTODATE, &bio->bi_flags));
739                 WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
740                 md_error(mddev, rdev);
741         }
742 
743         if (atomic_dec_and_test(&mddev->pending_writes))
744                 wake_up(&mddev->sb_wait);
745         bio_put(bio);
746 }
747 
748 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
749                    sector_t sector, int size, struct page *page)
750 {
751         /* write first size bytes of page to sector of rdev
752          * Increment mddev->pending_writes before returning
753          * and decrement it on completion, waking up sb_wait
754          * if zero is reached.
755          * If an error occurred, call md_error
756          */
757         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
758 
759         bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
760         bio->bi_iter.bi_sector = sector;
761         bio_add_page(bio, page, size, 0);
762         bio->bi_private = rdev;
763         bio->bi_end_io = super_written;
764 
765         atomic_inc(&mddev->pending_writes);
766         submit_bio(WRITE_FLUSH_FUA, bio);
767 }
768 
769 void md_super_wait(struct mddev *mddev)
770 {
771         /* wait for all superblock writes that were scheduled to complete */
772         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
773 }
774 
775 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
776                  struct page *page, int rw, bool metadata_op)
777 {
778         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
779         int ret;
780 
781         bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
782                 rdev->meta_bdev : rdev->bdev;
783         if (metadata_op)
784                 bio->bi_iter.bi_sector = sector + rdev->sb_start;
785         else if (rdev->mddev->reshape_position != MaxSector &&
786                  (rdev->mddev->reshape_backwards ==
787                   (sector >= rdev->mddev->reshape_position)))
788                 bio->bi_iter.bi_sector = sector + rdev->new_data_offset;
789         else
790                 bio->bi_iter.bi_sector = sector + rdev->data_offset;
791         bio_add_page(bio, page, size, 0);
792         submit_bio_wait(rw, bio);
793 
794         ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
795         bio_put(bio);
796         return ret;
797 }
798 EXPORT_SYMBOL_GPL(sync_page_io);
799 
800 static int read_disk_sb(struct md_rdev *rdev, int size)
801 {
802         char b[BDEVNAME_SIZE];
803 
804         if (rdev->sb_loaded)
805                 return 0;
806 
807         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
808                 goto fail;
809         rdev->sb_loaded = 1;
810         return 0;
811 
812 fail:
813         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
814                 bdevname(rdev->bdev,b));
815         return -EINVAL;
816 }
817 
818 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
819 {
820         return  sb1->set_uuid0 == sb2->set_uuid0 &&
821                 sb1->set_uuid1 == sb2->set_uuid1 &&
822                 sb1->set_uuid2 == sb2->set_uuid2 &&
823                 sb1->set_uuid3 == sb2->set_uuid3;
824 }
825 
826 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
827 {
828         int ret;
829         mdp_super_t *tmp1, *tmp2;
830 
831         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
832         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
833 
834         if (!tmp1 || !tmp2) {
835                 ret = 0;
836                 printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
837                 goto abort;
838         }
839 
840         *tmp1 = *sb1;
841         *tmp2 = *sb2;
842 
843         /*
844          * nr_disks is not constant
845          */
846         tmp1->nr_disks = 0;
847         tmp2->nr_disks = 0;
848 
849         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
850 abort:
851         kfree(tmp1);
852         kfree(tmp2);
853         return ret;
854 }
855 
856 static u32 md_csum_fold(u32 csum)
857 {
858         csum = (csum & 0xffff) + (csum >> 16);
859         return (csum & 0xffff) + (csum >> 16);
860 }
861 
862 static unsigned int calc_sb_csum(mdp_super_t *sb)
863 {
864         u64 newcsum = 0;
865         u32 *sb32 = (u32*)sb;
866         int i;
867         unsigned int disk_csum, csum;
868 
869         disk_csum = sb->sb_csum;
870         sb->sb_csum = 0;
871 
872         for (i = 0; i < MD_SB_BYTES/4 ; i++)
873                 newcsum += sb32[i];
874         csum = (newcsum & 0xffffffff) + (newcsum>>32);
875 
876 #ifdef CONFIG_ALPHA
877         /* This used to use csum_partial, which was wrong for several
878          * reasons including that different results are returned on
879          * different architectures.  It isn't critical that we get exactly
880          * the same return value as before (we always csum_fold before
881          * testing, and that removes any differences).  However as we
882          * know that csum_partial always returned a 16bit value on
883          * alphas, do a fold to maximise conformity to previous behaviour.
884          */
885         sb->sb_csum = md_csum_fold(disk_csum);
886 #else
887         sb->sb_csum = disk_csum;
888 #endif
889         return csum;
890 }
891 
892 /*
893  * Handle superblock details.
894  * We want to be able to handle multiple superblock formats
895  * so we have a common interface to them all, and an array of
896  * different handlers.
897  * We rely on user-space to write the initial superblock, and support
898  * reading and updating of superblocks.
899  * Interface methods are:
900  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
901  *      loads and validates a superblock on dev.
902  *      if refdev != NULL, compare superblocks on both devices
903  *    Return:
904  *      0 - dev has a superblock that is compatible with refdev
905  *      1 - dev has a superblock that is compatible and newer than refdev
906  *          so dev should be used as the refdev in future
907  *     -EINVAL superblock incompatible or invalid
908  *     -othererror e.g. -EIO
909  *
910  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
911  *      Verify that dev is acceptable into mddev.
912  *       The first time, mddev->raid_disks will be 0, and data from
913  *       dev should be merged in.  Subsequent calls check that dev
914  *       is new enough.  Return 0 or -EINVAL
915  *
916  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
917  *     Update the superblock for rdev with data in mddev
918  *     This does not write to disc.
919  *
920  */
921 
922 struct super_type  {
923         char                *name;
924         struct module       *owner;
925         int                 (*load_super)(struct md_rdev *rdev,
926                                           struct md_rdev *refdev,
927                                           int minor_version);
928         int                 (*validate_super)(struct mddev *mddev,
929                                               struct md_rdev *rdev);
930         void                (*sync_super)(struct mddev *mddev,
931                                           struct md_rdev *rdev);
932         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
933                                                 sector_t num_sectors);
934         int                 (*allow_new_offset)(struct md_rdev *rdev,
935                                                 unsigned long long new_offset);
936 };
937 
938 /*
939  * Check that the given mddev has no bitmap.
940  *
941  * This function is called from the run method of all personalities that do not
942  * support bitmaps. It prints an error message and returns non-zero if mddev
943  * has a bitmap. Otherwise, it returns 0.
944  *
945  */
946 int md_check_no_bitmap(struct mddev *mddev)
947 {
948         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
949                 return 0;
950         printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
951                 mdname(mddev), mddev->pers->name);
952         return 1;
953 }
954 EXPORT_SYMBOL(md_check_no_bitmap);
955 
956 /*
957  * load_super for 0.90.0
958  */
959 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
960 {
961         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
962         mdp_super_t *sb;
963         int ret;
964 
965         /*
966          * Calculate the position of the superblock (512byte sectors),
967          * it's at the end of the disk.
968          *
969          * It also happens to be a multiple of 4Kb.
970          */
971         rdev->sb_start = calc_dev_sboffset(rdev);
972 
973         ret = read_disk_sb(rdev, MD_SB_BYTES);
974         if (ret) return ret;
975 
976         ret = -EINVAL;
977 
978         bdevname(rdev->bdev, b);
979         sb = page_address(rdev->sb_page);
980 
981         if (sb->md_magic != MD_SB_MAGIC) {
982                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
983                        b);
984                 goto abort;
985         }
986 
987         if (sb->major_version != 0 ||
988             sb->minor_version < 90 ||
989             sb->minor_version > 91) {
990                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
991                         sb->major_version, sb->minor_version,
992                         b);
993                 goto abort;
994         }
995 
996         if (sb->raid_disks <= 0)
997                 goto abort;
998 
999         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1000                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1001                         b);
1002                 goto abort;
1003         }
1004 
1005         rdev->preferred_minor = sb->md_minor;
1006         rdev->data_offset = 0;
1007         rdev->new_data_offset = 0;
1008         rdev->sb_size = MD_SB_BYTES;
1009         rdev->badblocks.shift = -1;
1010 
1011         if (sb->level == LEVEL_MULTIPATH)
1012                 rdev->desc_nr = -1;
1013         else
1014                 rdev->desc_nr = sb->this_disk.number;
1015 
1016         if (!refdev) {
1017                 ret = 1;
1018         } else {
1019                 __u64 ev1, ev2;
1020                 mdp_super_t *refsb = page_address(refdev->sb_page);
1021                 if (!uuid_equal(refsb, sb)) {
1022                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
1023                                 b, bdevname(refdev->bdev,b2));
1024                         goto abort;
1025                 }
1026                 if (!sb_equal(refsb, sb)) {
1027                         printk(KERN_WARNING "md: %s has same UUID"
1028                                " but different superblock to %s\n",
1029                                b, bdevname(refdev->bdev, b2));
1030                         goto abort;
1031                 }
1032                 ev1 = md_event(sb);
1033                 ev2 = md_event(refsb);
1034                 if (ev1 > ev2)
1035                         ret = 1;
1036                 else
1037                         ret = 0;
1038         }
1039         rdev->sectors = rdev->sb_start;
1040         /* Limit to 4TB as metadata cannot record more than that.
1041          * (not needed for Linear and RAID0 as metadata doesn't
1042          * record this size)
1043          */
1044         if (rdev->sectors >= (2ULL << 32) && sb->level >= 1)
1045                 rdev->sectors = (2ULL << 32) - 2;
1046 
1047         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1048                 /* "this cannot possibly happen" ... */
1049                 ret = -EINVAL;
1050 
1051  abort:
1052         return ret;
1053 }
1054 
1055 /*
1056  * validate_super for 0.90.0
1057  */
1058 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1059 {
1060         mdp_disk_t *desc;
1061         mdp_super_t *sb = page_address(rdev->sb_page);
1062         __u64 ev1 = md_event(sb);
1063 
1064         rdev->raid_disk = -1;
1065         clear_bit(Faulty, &rdev->flags);
1066         clear_bit(In_sync, &rdev->flags);
1067         clear_bit(Bitmap_sync, &rdev->flags);
1068         clear_bit(WriteMostly, &rdev->flags);
1069 
1070         if (mddev->raid_disks == 0) {
1071                 mddev->major_version = 0;
1072                 mddev->minor_version = sb->minor_version;
1073                 mddev->patch_version = sb->patch_version;
1074                 mddev->external = 0;
1075                 mddev->chunk_sectors = sb->chunk_size >> 9;
1076                 mddev->ctime = sb->ctime;
1077                 mddev->utime = sb->utime;
1078                 mddev->level = sb->level;
1079                 mddev->clevel[0] = 0;
1080                 mddev->layout = sb->layout;
1081                 mddev->raid_disks = sb->raid_disks;
1082                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1083                 mddev->events = ev1;
1084                 mddev->bitmap_info.offset = 0;
1085                 mddev->bitmap_info.space = 0;
1086                 /* bitmap can use 60 K after the 4K superblocks */
1087                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1088                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1089                 mddev->reshape_backwards = 0;
1090 
1091                 if (mddev->minor_version >= 91) {
1092                         mddev->reshape_position = sb->reshape_position;
1093                         mddev->delta_disks = sb->delta_disks;
1094                         mddev->new_level = sb->new_level;
1095                         mddev->new_layout = sb->new_layout;
1096                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1097                         if (mddev->delta_disks < 0)
1098                                 mddev->reshape_backwards = 1;
1099                 } else {
1100                         mddev->reshape_position = MaxSector;
1101                         mddev->delta_disks = 0;
1102                         mddev->new_level = mddev->level;
1103                         mddev->new_layout = mddev->layout;
1104                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1105                 }
1106 
1107                 if (sb->state & (1<<MD_SB_CLEAN))
1108                         mddev->recovery_cp = MaxSector;
1109                 else {
1110                         if (sb->events_hi == sb->cp_events_hi &&
1111                                 sb->events_lo == sb->cp_events_lo) {
1112                                 mddev->recovery_cp = sb->recovery_cp;
1113                         } else
1114                                 mddev->recovery_cp = 0;
1115                 }
1116 
1117                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1118                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1119                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1120                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1121 
1122                 mddev->max_disks = MD_SB_DISKS;
1123 
1124                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1125                     mddev->bitmap_info.file == NULL) {
1126                         mddev->bitmap_info.offset =
1127                                 mddev->bitmap_info.default_offset;
1128                         mddev->bitmap_info.space =
1129                                 mddev->bitmap_info.default_space;
1130                 }
1131 
1132         } else if (mddev->pers == NULL) {
1133                 /* Insist on good event counter while assembling, except
1134                  * for spares (which don't need an event count) */
1135                 ++ev1;
1136                 if (sb->disks[rdev->desc_nr].state & (
1137                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1138                         if (ev1 < mddev->events)
1139                                 return -EINVAL;
1140         } else if (mddev->bitmap) {
1141                 /* if adding to array with a bitmap, then we can accept an
1142                  * older device ... but not too old.
1143                  */
1144                 if (ev1 < mddev->bitmap->events_cleared)
1145                         return 0;
1146                 if (ev1 < mddev->events)
1147                         set_bit(Bitmap_sync, &rdev->flags);
1148         } else {
1149                 if (ev1 < mddev->events)
1150                         /* just a hot-add of a new device, leave raid_disk at -1 */
1151                         return 0;
1152         }
1153 
1154         if (mddev->level != LEVEL_MULTIPATH) {
1155                 desc = sb->disks + rdev->desc_nr;
1156 
1157                 if (desc->state & (1<<MD_DISK_FAULTY))
1158                         set_bit(Faulty, &rdev->flags);
1159                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1160                             desc->raid_disk < mddev->raid_disks */) {
1161                         set_bit(In_sync, &rdev->flags);
1162                         rdev->raid_disk = desc->raid_disk;
1163                         rdev->saved_raid_disk = desc->raid_disk;
1164                 } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1165                         /* active but not in sync implies recovery up to
1166                          * reshape position.  We don't know exactly where
1167                          * that is, so set to zero for now */
1168                         if (mddev->minor_version >= 91) {
1169                                 rdev->recovery_offset = 0;
1170                                 rdev->raid_disk = desc->raid_disk;
1171                         }
1172                 }
1173                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1174                         set_bit(WriteMostly, &rdev->flags);
1175         } else /* MULTIPATH are always insync */
1176                 set_bit(In_sync, &rdev->flags);
1177         return 0;
1178 }
1179 
1180 /*
1181  * sync_super for 0.90.0
1182  */
1183 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1184 {
1185         mdp_super_t *sb;
1186         struct md_rdev *rdev2;
1187         int next_spare = mddev->raid_disks;
1188 
1189         /* make rdev->sb match mddev data..
1190          *
1191          * 1/ zero out disks
1192          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1193          * 3/ any empty disks < next_spare become removed
1194          *
1195          * disks[0] gets initialised to REMOVED because
1196          * we cannot be sure from other fields if it has
1197          * been initialised or not.
1198          */
1199         int i;
1200         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1201 
1202         rdev->sb_size = MD_SB_BYTES;
1203 
1204         sb = page_address(rdev->sb_page);
1205 
1206         memset(sb, 0, sizeof(*sb));
1207 
1208         sb->md_magic = MD_SB_MAGIC;
1209         sb->major_version = mddev->major_version;
1210         sb->patch_version = mddev->patch_version;
1211         sb->gvalid_words  = 0; /* ignored */
1212         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1213         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1214         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1215         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1216 
1217         sb->ctime = mddev->ctime;
1218         sb->level = mddev->level;
1219         sb->size = mddev->dev_sectors / 2;
1220         sb->raid_disks = mddev->raid_disks;
1221         sb->md_minor = mddev->md_minor;
1222         sb->not_persistent = 0;
1223         sb->utime = mddev->utime;
1224         sb->state = 0;
1225         sb->events_hi = (mddev->events>>32);
1226         sb->events_lo = (u32)mddev->events;
1227 
1228         if (mddev->reshape_position == MaxSector)
1229                 sb->minor_version = 90;
1230         else {
1231                 sb->minor_version = 91;
1232                 sb->reshape_position = mddev->reshape_position;
1233                 sb->new_level = mddev->new_level;
1234                 sb->delta_disks = mddev->delta_disks;
1235                 sb->new_layout = mddev->new_layout;
1236                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1237         }
1238         mddev->minor_version = sb->minor_version;
1239         if (mddev->in_sync)
1240         {
1241                 sb->recovery_cp = mddev->recovery_cp;
1242                 sb->cp_events_hi = (mddev->events>>32);
1243                 sb->cp_events_lo = (u32)mddev->events;
1244                 if (mddev->recovery_cp == MaxSector)
1245                         sb->state = (1<< MD_SB_CLEAN);
1246         } else
1247                 sb->recovery_cp = 0;
1248 
1249         sb->layout = mddev->layout;
1250         sb->chunk_size = mddev->chunk_sectors << 9;
1251 
1252         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1253                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1254 
1255         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1256         rdev_for_each(rdev2, mddev) {
1257                 mdp_disk_t *d;
1258                 int desc_nr;
1259                 int is_active = test_bit(In_sync, &rdev2->flags);
1260 
1261                 if (rdev2->raid_disk >= 0 &&
1262                     sb->minor_version >= 91)
1263                         /* we have nowhere to store the recovery_offset,
1264                          * but if it is not below the reshape_position,
1265                          * we can piggy-back on that.
1266                          */
1267                         is_active = 1;
1268                 if (rdev2->raid_disk < 0 ||
1269                     test_bit(Faulty, &rdev2->flags))
1270                         is_active = 0;
1271                 if (is_active)
1272                         desc_nr = rdev2->raid_disk;
1273                 else
1274                         desc_nr = next_spare++;
1275                 rdev2->desc_nr = desc_nr;
1276                 d = &sb->disks[rdev2->desc_nr];
1277                 nr_disks++;
1278                 d->number = rdev2->desc_nr;
1279                 d->major = MAJOR(rdev2->bdev->bd_dev);
1280                 d->minor = MINOR(rdev2->bdev->bd_dev);
1281                 if (is_active)
1282                         d->raid_disk = rdev2->raid_disk;
1283                 else
1284                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1285                 if (test_bit(Faulty, &rdev2->flags))
1286                         d->state = (1<<MD_DISK_FAULTY);
1287                 else if (is_active) {
1288                         d->state = (1<<MD_DISK_ACTIVE);
1289                         if (test_bit(In_sync, &rdev2->flags))
1290                                 d->state |= (1<<MD_DISK_SYNC);
1291                         active++;
1292                         working++;
1293                 } else {
1294                         d->state = 0;
1295                         spare++;
1296                         working++;
1297                 }
1298                 if (test_bit(WriteMostly, &rdev2->flags))
1299                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1300         }
1301         /* now set the "removed" and "faulty" bits on any missing devices */
1302         for (i=0 ; i < mddev->raid_disks ; i++) {
1303                 mdp_disk_t *d = &sb->disks[i];
1304                 if (d->state == 0 && d->number == 0) {
1305                         d->number = i;
1306                         d->raid_disk = i;
1307                         d->state = (1<<MD_DISK_REMOVED);
1308                         d->state |= (1<<MD_DISK_FAULTY);
1309                         failed++;
1310                 }
1311         }
1312         sb->nr_disks = nr_disks;
1313         sb->active_disks = active;
1314         sb->working_disks = working;
1315         sb->failed_disks = failed;
1316         sb->spare_disks = spare;
1317 
1318         sb->this_disk = sb->disks[rdev->desc_nr];
1319         sb->sb_csum = calc_sb_csum(sb);
1320 }
1321 
1322 /*
1323  * rdev_size_change for 0.90.0
1324  */
1325 static unsigned long long
1326 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1327 {
1328         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1329                 return 0; /* component must fit device */
1330         if (rdev->mddev->bitmap_info.offset)
1331                 return 0; /* can't move bitmap */
1332         rdev->sb_start = calc_dev_sboffset(rdev);
1333         if (!num_sectors || num_sectors > rdev->sb_start)
1334                 num_sectors = rdev->sb_start;
1335         /* Limit to 4TB as metadata cannot record more than that.
1336          * 4TB == 2^32 KB, or 2*2^32 sectors.
1337          */
1338         if (num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
1339                 num_sectors = (2ULL << 32) - 2;
1340         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1341                        rdev->sb_page);
1342         md_super_wait(rdev->mddev);
1343         return num_sectors;
1344 }
1345 
1346 static int
1347 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1348 {
1349         /* non-zero offset changes not possible with v0.90 */
1350         return new_offset == 0;
1351 }
1352 
1353 /*
1354  * version 1 superblock
1355  */
1356 
1357 static __le32 calc_sb_1_csum(struct mdp_superblock_1 *sb)
1358 {
1359         __le32 disk_csum;
1360         u32 csum;
1361         unsigned long long newcsum;
1362         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1363         __le32 *isuper = (__le32*)sb;
1364 
1365         disk_csum = sb->sb_csum;
1366         sb->sb_csum = 0;
1367         newcsum = 0;
1368         for (; size >= 4; size -= 4)
1369                 newcsum += le32_to_cpu(*isuper++);
1370 
1371         if (size == 2)
1372                 newcsum += le16_to_cpu(*(__le16*) isuper);
1373 
1374         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1375         sb->sb_csum = disk_csum;
1376         return cpu_to_le32(csum);
1377 }
1378 
1379 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1380                             int acknowledged);
1381 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1382 {
1383         struct mdp_superblock_1 *sb;
1384         int ret;
1385         sector_t sb_start;
1386         sector_t sectors;
1387         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1388         int bmask;
1389 
1390         /*
1391          * Calculate the position of the superblock in 512byte sectors.
1392          * It is always aligned to a 4K boundary and
1393          * depeding on minor_version, it can be:
1394          * 0: At least 8K, but less than 12K, from end of device
1395          * 1: At start of device
1396          * 2: 4K from start of device.
1397          */
1398         switch(minor_version) {
1399         case 0:
1400                 sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1401                 sb_start -= 8*2;
1402                 sb_start &= ~(sector_t)(4*2-1);
1403                 break;
1404         case 1:
1405                 sb_start = 0;
1406                 break;
1407         case 2:
1408                 sb_start = 8;
1409                 break;
1410         default:
1411                 return -EINVAL;
1412         }
1413         rdev->sb_start = sb_start;
1414 
1415         /* superblock is rarely larger than 1K, but it can be larger,
1416          * and it is safe to read 4k, so we do that
1417          */
1418         ret = read_disk_sb(rdev, 4096);
1419         if (ret) return ret;
1420 
1421         sb = page_address(rdev->sb_page);
1422 
1423         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1424             sb->major_version != cpu_to_le32(1) ||
1425             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1426             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1427             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1428                 return -EINVAL;
1429 
1430         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1431                 printk("md: invalid superblock checksum on %s\n",
1432                         bdevname(rdev->bdev,b));
1433                 return -EINVAL;
1434         }
1435         if (le64_to_cpu(sb->data_size) < 10) {
1436                 printk("md: data_size too small on %s\n",
1437                        bdevname(rdev->bdev,b));
1438                 return -EINVAL;
1439         }
1440         if (sb->pad0 ||
1441             sb->pad3[0] ||
1442             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1443                 /* Some padding is non-zero, might be a new feature */
1444                 return -EINVAL;
1445 
1446         rdev->preferred_minor = 0xffff;
1447         rdev->data_offset = le64_to_cpu(sb->data_offset);
1448         rdev->new_data_offset = rdev->data_offset;
1449         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1450             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1451                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1452         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1453 
1454         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1455         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1456         if (rdev->sb_size & bmask)
1457                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1458 
1459         if (minor_version
1460             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1461                 return -EINVAL;
1462         if (minor_version
1463             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1464                 return -EINVAL;
1465 
1466         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1467                 rdev->desc_nr = -1;
1468         else
1469                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1470 
1471         if (!rdev->bb_page) {
1472                 rdev->bb_page = alloc_page(GFP_KERNEL);
1473                 if (!rdev->bb_page)
1474                         return -ENOMEM;
1475         }
1476         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1477             rdev->badblocks.count == 0) {
1478                 /* need to load the bad block list.
1479                  * Currently we limit it to one page.
1480                  */
1481                 s32 offset;
1482                 sector_t bb_sector;
1483                 u64 *bbp;
1484                 int i;
1485                 int sectors = le16_to_cpu(sb->bblog_size);
1486                 if (sectors > (PAGE_SIZE / 512))
1487                         return -EINVAL;
1488                 offset = le32_to_cpu(sb->bblog_offset);
1489                 if (offset == 0)
1490                         return -EINVAL;
1491                 bb_sector = (long long)offset;
1492                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1493                                   rdev->bb_page, READ, true))
1494                         return -EIO;
1495                 bbp = (u64 *)page_address(rdev->bb_page);
1496                 rdev->badblocks.shift = sb->bblog_shift;
1497                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1498                         u64 bb = le64_to_cpu(*bbp);
1499                         int count = bb & (0x3ff);
1500                         u64 sector = bb >> 10;
1501                         sector <<= sb->bblog_shift;
1502                         count <<= sb->bblog_shift;
1503                         if (bb + 1 == 0)
1504                                 break;
1505                         if (md_set_badblocks(&rdev->badblocks,
1506                                              sector, count, 1) == 0)
1507                                 return -EINVAL;
1508                 }
1509         } else if (sb->bblog_offset != 0)
1510                 rdev->badblocks.shift = 0;
1511 
1512         if (!refdev) {
1513                 ret = 1;
1514         } else {
1515                 __u64 ev1, ev2;
1516                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1517 
1518                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1519                     sb->level != refsb->level ||
1520                     sb->layout != refsb->layout ||
1521                     sb->chunksize != refsb->chunksize) {
1522                         printk(KERN_WARNING "md: %s has strangely different"
1523                                 " superblock to %s\n",
1524                                 bdevname(rdev->bdev,b),
1525                                 bdevname(refdev->bdev,b2));
1526                         return -EINVAL;
1527                 }
1528                 ev1 = le64_to_cpu(sb->events);
1529                 ev2 = le64_to_cpu(refsb->events);
1530 
1531                 if (ev1 > ev2)
1532                         ret = 1;
1533                 else
1534                         ret = 0;
1535         }
1536         if (minor_version) {
1537                 sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1538                 sectors -= rdev->data_offset;
1539         } else
1540                 sectors = rdev->sb_start;
1541         if (sectors < le64_to_cpu(sb->data_size))
1542                 return -EINVAL;
1543         rdev->sectors = le64_to_cpu(sb->data_size);
1544         return ret;
1545 }
1546 
1547 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1548 {
1549         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1550         __u64 ev1 = le64_to_cpu(sb->events);
1551 
1552         rdev->raid_disk = -1;
1553         clear_bit(Faulty, &rdev->flags);
1554         clear_bit(In_sync, &rdev->flags);
1555         clear_bit(Bitmap_sync, &rdev->flags);
1556         clear_bit(WriteMostly, &rdev->flags);
1557 
1558         if (mddev->raid_disks == 0) {
1559                 mddev->major_version = 1;
1560                 mddev->patch_version = 0;
1561                 mddev->external = 0;
1562                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1563                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1564                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1565                 mddev->level = le32_to_cpu(sb->level);
1566                 mddev->clevel[0] = 0;
1567                 mddev->layout = le32_to_cpu(sb->layout);
1568                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1569                 mddev->dev_sectors = le64_to_cpu(sb->size);
1570                 mddev->events = ev1;
1571                 mddev->bitmap_info.offset = 0;
1572                 mddev->bitmap_info.space = 0;
1573                 /* Default location for bitmap is 1K after superblock
1574                  * using 3K - total of 4K
1575                  */
1576                 mddev->bitmap_info.default_offset = 1024 >> 9;
1577                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1578                 mddev->reshape_backwards = 0;
1579 
1580                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1581                 memcpy(mddev->uuid, sb->set_uuid, 16);
1582 
1583                 mddev->max_disks =  (4096-256)/2;
1584 
1585                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1586                     mddev->bitmap_info.file == NULL) {
1587                         mddev->bitmap_info.offset =
1588                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1589                         /* Metadata doesn't record how much space is available.
1590                          * For 1.0, we assume we can use up to the superblock
1591                          * if before, else to 4K beyond superblock.
1592                          * For others, assume no change is possible.
1593                          */
1594                         if (mddev->minor_version > 0)
1595                                 mddev->bitmap_info.space = 0;
1596                         else if (mddev->bitmap_info.offset > 0)
1597                                 mddev->bitmap_info.space =
1598                                         8 - mddev->bitmap_info.offset;
1599                         else
1600                                 mddev->bitmap_info.space =
1601                                         -mddev->bitmap_info.offset;
1602                 }
1603 
1604                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1605                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1606                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1607                         mddev->new_level = le32_to_cpu(sb->new_level);
1608                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1609                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1610                         if (mddev->delta_disks < 0 ||
1611                             (mddev->delta_disks == 0 &&
1612                              (le32_to_cpu(sb->feature_map)
1613                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1614                                 mddev->reshape_backwards = 1;
1615                 } else {
1616                         mddev->reshape_position = MaxSector;
1617                         mddev->delta_disks = 0;
1618                         mddev->new_level = mddev->level;
1619                         mddev->new_layout = mddev->layout;
1620                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1621                 }
1622 
1623         } else if (mddev->pers == NULL) {
1624                 /* Insist of good event counter while assembling, except for
1625                  * spares (which don't need an event count) */
1626                 ++ev1;
1627                 if (rdev->desc_nr >= 0 &&
1628                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1629                     le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1630                         if (ev1 < mddev->events)
1631                                 return -EINVAL;
1632         } else if (mddev->bitmap) {
1633                 /* If adding to array with a bitmap, then we can accept an
1634                  * older device, but not too old.
1635                  */
1636                 if (ev1 < mddev->bitmap->events_cleared)
1637                         return 0;
1638                 if (ev1 < mddev->events)
1639                         set_bit(Bitmap_sync, &rdev->flags);
1640         } else {
1641                 if (ev1 < mddev->events)
1642                         /* just a hot-add of a new device, leave raid_disk at -1 */
1643                         return 0;
1644         }
1645         if (mddev->level != LEVEL_MULTIPATH) {
1646                 int role;
1647                 if (rdev->desc_nr < 0 ||
1648                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1649                         role = 0xffff;
1650                         rdev->desc_nr = -1;
1651                 } else
1652                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1653                 switch(role) {
1654                 case 0xffff: /* spare */
1655                         break;
1656                 case 0xfffe: /* faulty */
1657                         set_bit(Faulty, &rdev->flags);
1658                         break;
1659                 default:
1660                         rdev->saved_raid_disk = role;
1661                         if ((le32_to_cpu(sb->feature_map) &
1662                              MD_FEATURE_RECOVERY_OFFSET)) {
1663                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1664                                 if (!(le32_to_cpu(sb->feature_map) &
1665                                       MD_FEATURE_RECOVERY_BITMAP))
1666                                         rdev->saved_raid_disk = -1;
1667                         } else
1668                                 set_bit(In_sync, &rdev->flags);
1669                         rdev->raid_disk = role;
1670                         break;
1671                 }
1672                 if (sb->devflags & WriteMostly1)
1673                         set_bit(WriteMostly, &rdev->flags);
1674                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1675                         set_bit(Replacement, &rdev->flags);
1676         } else /* MULTIPATH are always insync */
1677                 set_bit(In_sync, &rdev->flags);
1678 
1679         return 0;
1680 }
1681 
1682 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1683 {
1684         struct mdp_superblock_1 *sb;
1685         struct md_rdev *rdev2;
1686         int max_dev, i;
1687         /* make rdev->sb match mddev and rdev data. */
1688 
1689         sb = page_address(rdev->sb_page);
1690 
1691         sb->feature_map = 0;
1692         sb->pad0 = 0;
1693         sb->recovery_offset = cpu_to_le64(0);
1694         memset(sb->pad3, 0, sizeof(sb->pad3));
1695 
1696         sb->utime = cpu_to_le64((__u64)mddev->utime);
1697         sb->events = cpu_to_le64(mddev->events);
1698         if (mddev->in_sync)
1699                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1700         else
1701                 sb->resync_offset = cpu_to_le64(0);
1702 
1703         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1704 
1705         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1706         sb->size = cpu_to_le64(mddev->dev_sectors);
1707         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1708         sb->level = cpu_to_le32(mddev->level);
1709         sb->layout = cpu_to_le32(mddev->layout);
1710 
1711         if (test_bit(WriteMostly, &rdev->flags))
1712                 sb->devflags |= WriteMostly1;
1713         else
1714                 sb->devflags &= ~WriteMostly1;
1715         sb->data_offset = cpu_to_le64(rdev->data_offset);
1716         sb->data_size = cpu_to_le64(rdev->sectors);
1717 
1718         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1719                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1720                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1721         }
1722 
1723         if (rdev->raid_disk >= 0 &&
1724             !test_bit(In_sync, &rdev->flags)) {
1725                 sb->feature_map |=
1726                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1727                 sb->recovery_offset =
1728                         cpu_to_le64(rdev->recovery_offset);
1729                 if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
1730                         sb->feature_map |=
1731                                 cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
1732         }
1733         if (test_bit(Replacement, &rdev->flags))
1734                 sb->feature_map |=
1735                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
1736 
1737         if (mddev->reshape_position != MaxSector) {
1738                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1739                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1740                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1741                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1742                 sb->new_level = cpu_to_le32(mddev->new_level);
1743                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1744                 if (mddev->delta_disks == 0 &&
1745                     mddev->reshape_backwards)
1746                         sb->feature_map
1747                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1748                 if (rdev->new_data_offset != rdev->data_offset) {
1749                         sb->feature_map
1750                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1751                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1752                                                              - rdev->data_offset));
1753                 }
1754         }
1755 
1756         if (rdev->badblocks.count == 0)
1757                 /* Nothing to do for bad blocks*/ ;
1758         else if (sb->bblog_offset == 0)
1759                 /* Cannot record bad blocks on this device */
1760                 md_error(mddev, rdev);
1761         else {
1762                 struct badblocks *bb = &rdev->badblocks;
1763                 u64 *bbp = (u64 *)page_address(rdev->bb_page);
1764                 u64 *p = bb->page;
1765                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1766                 if (bb->changed) {
1767                         unsigned seq;
1768 
1769 retry:
1770                         seq = read_seqbegin(&bb->lock);
1771 
1772                         memset(bbp, 0xff, PAGE_SIZE);
1773 
1774                         for (i = 0 ; i < bb->count ; i++) {
1775                                 u64 internal_bb = p[i];
1776                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1777                                                 | BB_LEN(internal_bb));
1778                                 bbp[i] = cpu_to_le64(store_bb);
1779                         }
1780                         bb->changed = 0;
1781                         if (read_seqretry(&bb->lock, seq))
1782                                 goto retry;
1783 
1784                         bb->sector = (rdev->sb_start +
1785                                       (int)le32_to_cpu(sb->bblog_offset));
1786                         bb->size = le16_to_cpu(sb->bblog_size);
1787                 }
1788         }
1789 
1790         max_dev = 0;
1791         rdev_for_each(rdev2, mddev)
1792                 if (rdev2->desc_nr+1 > max_dev)
1793                         max_dev = rdev2->desc_nr+1;
1794 
1795         if (max_dev > le32_to_cpu(sb->max_dev)) {
1796                 int bmask;
1797                 sb->max_dev = cpu_to_le32(max_dev);
1798                 rdev->sb_size = max_dev * 2 + 256;
1799                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1800                 if (rdev->sb_size & bmask)
1801                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
1802         } else
1803                 max_dev = le32_to_cpu(sb->max_dev);
1804 
1805         for (i=0; i<max_dev;i++)
1806                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
1807 
1808         rdev_for_each(rdev2, mddev) {
1809                 i = rdev2->desc_nr;
1810                 if (test_bit(Faulty, &rdev2->flags))
1811                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
1812                 else if (test_bit(In_sync, &rdev2->flags))
1813                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1814                 else if (rdev2->raid_disk >= 0)
1815                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1816                 else
1817                         sb->dev_roles[i] = cpu_to_le16(0xffff);
1818         }
1819 
1820         sb->sb_csum = calc_sb_1_csum(sb);
1821 }
1822 
1823 static unsigned long long
1824 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1825 {
1826         struct mdp_superblock_1 *sb;
1827         sector_t max_sectors;
1828         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1829                 return 0; /* component must fit device */
1830         if (rdev->data_offset != rdev->new_data_offset)
1831                 return 0; /* too confusing */
1832         if (rdev->sb_start < rdev->data_offset) {
1833                 /* minor versions 1 and 2; superblock before data */
1834                 max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1835                 max_sectors -= rdev->data_offset;
1836                 if (!num_sectors || num_sectors > max_sectors)
1837                         num_sectors = max_sectors;
1838         } else if (rdev->mddev->bitmap_info.offset) {
1839                 /* minor version 0 with bitmap we can't move */
1840                 return 0;
1841         } else {
1842                 /* minor version 0; superblock after data */
1843                 sector_t sb_start;
1844                 sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1845                 sb_start &= ~(sector_t)(4*2 - 1);
1846                 max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1847                 if (!num_sectors || num_sectors > max_sectors)
1848                         num_sectors = max_sectors;
1849                 rdev->sb_start = sb_start;
1850         }
1851         sb = page_address(rdev->sb_page);
1852         sb->data_size = cpu_to_le64(num_sectors);
1853         sb->super_offset = rdev->sb_start;
1854         sb->sb_csum = calc_sb_1_csum(sb);
1855         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1856                        rdev->sb_page);
1857         md_super_wait(rdev->mddev);
1858         return num_sectors;
1859 
1860 }
1861 
1862 static int
1863 super_1_allow_new_offset(struct md_rdev *rdev,
1864                          unsigned long long new_offset)
1865 {
1866         /* All necessary checks on new >= old have been done */
1867         struct bitmap *bitmap;
1868         if (new_offset >= rdev->data_offset)
1869                 return 1;
1870 
1871         /* with 1.0 metadata, there is no metadata to tread on
1872          * so we can always move back */
1873         if (rdev->mddev->minor_version == 0)
1874                 return 1;
1875 
1876         /* otherwise we must be sure not to step on
1877          * any metadata, so stay:
1878          * 36K beyond start of superblock
1879          * beyond end of badblocks
1880          * beyond write-intent bitmap
1881          */
1882         if (rdev->sb_start + (32+4)*2 > new_offset)
1883                 return 0;
1884         bitmap = rdev->mddev->bitmap;
1885         if (bitmap && !rdev->mddev->bitmap_info.file &&
1886             rdev->sb_start + rdev->mddev->bitmap_info.offset +
1887             bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1888                 return 0;
1889         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1890                 return 0;
1891 
1892         return 1;
1893 }
1894 
1895 static struct super_type super_types[] = {
1896         [0] = {
1897                 .name   = "0.90.0",
1898                 .owner  = THIS_MODULE,
1899                 .load_super         = super_90_load,
1900                 .validate_super     = super_90_validate,
1901                 .sync_super         = super_90_sync,
1902                 .rdev_size_change   = super_90_rdev_size_change,
1903                 .allow_new_offset   = super_90_allow_new_offset,
1904         },
1905         [1] = {
1906                 .name   = "md-1",
1907                 .owner  = THIS_MODULE,
1908                 .load_super         = super_1_load,
1909                 .validate_super     = super_1_validate,
1910                 .sync_super         = super_1_sync,
1911                 .rdev_size_change   = super_1_rdev_size_change,
1912                 .allow_new_offset   = super_1_allow_new_offset,
1913         },
1914 };
1915 
1916 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1917 {
1918         if (mddev->sync_super) {
1919                 mddev->sync_super(mddev, rdev);
1920                 return;
1921         }
1922 
1923         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1924 
1925         super_types[mddev->major_version].sync_super(mddev, rdev);
1926 }
1927 
1928 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1929 {
1930         struct md_rdev *rdev, *rdev2;
1931 
1932         rcu_read_lock();
1933         rdev_for_each_rcu(rdev, mddev1)
1934                 rdev_for_each_rcu(rdev2, mddev2)
1935                         if (rdev->bdev->bd_contains ==
1936                             rdev2->bdev->bd_contains) {
1937                                 rcu_read_unlock();
1938                                 return 1;
1939                         }
1940         rcu_read_unlock();
1941         return 0;
1942 }
1943 
1944 static LIST_HEAD(pending_raid_disks);
1945 
1946 /*
1947  * Try to register data integrity profile for an mddev
1948  *
1949  * This is called when an array is started and after a disk has been kicked
1950  * from the array. It only succeeds if all working and active component devices
1951  * are integrity capable with matching profiles.
1952  */
1953 int md_integrity_register(struct mddev *mddev)
1954 {
1955         struct md_rdev *rdev, *reference = NULL;
1956 
1957         if (list_empty(&mddev->disks))
1958                 return 0; /* nothing to do */
1959         if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1960                 return 0; /* shouldn't register, or already is */
1961         rdev_for_each(rdev, mddev) {
1962                 /* skip spares and non-functional disks */
1963                 if (test_bit(Faulty, &rdev->flags))
1964                         continue;
1965                 if (rdev->raid_disk < 0)
1966                         continue;
1967                 if (!reference) {
1968                         /* Use the first rdev as the reference */
1969                         reference = rdev;
1970                         continue;
1971                 }
1972                 /* does this rdev's profile match the reference profile? */
1973                 if (blk_integrity_compare(reference->bdev->bd_disk,
1974                                 rdev->bdev->bd_disk) < 0)
1975                         return -EINVAL;
1976         }
1977         if (!reference || !bdev_get_integrity(reference->bdev))
1978                 return 0;
1979         /*
1980          * All component devices are integrity capable and have matching
1981          * profiles, register the common profile for the md device.
1982          */
1983         if (blk_integrity_register(mddev->gendisk,
1984                         bdev_get_integrity(reference->bdev)) != 0) {
1985                 printk(KERN_ERR "md: failed to register integrity for %s\n",
1986                         mdname(mddev));
1987                 return -EINVAL;
1988         }
1989         printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
1990         if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
1991                 printk(KERN_ERR "md: failed to create integrity pool for %s\n",
1992                        mdname(mddev));
1993                 return -EINVAL;
1994         }
1995         return 0;
1996 }
1997 EXPORT_SYMBOL(md_integrity_register);
1998 
1999 /* Disable data integrity if non-capable/non-matching disk is being added */
2000 void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2001 {
2002         struct blk_integrity *bi_rdev;
2003         struct blk_integrity *bi_mddev;
2004 
2005         if (!mddev->gendisk)
2006                 return;
2007 
2008         bi_rdev = bdev_get_integrity(rdev->bdev);
2009         bi_mddev = blk_get_integrity(mddev->gendisk);
2010 
2011         if (!bi_mddev) /* nothing to do */
2012                 return;
2013         if (rdev->raid_disk < 0) /* skip spares */
2014                 return;
2015         if (bi_rdev && blk_integrity_compare(mddev->gendisk,
2016                                              rdev->bdev->bd_disk) >= 0)
2017                 return;
2018         printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
2019         blk_integrity_unregister(mddev->gendisk);
2020 }
2021 EXPORT_SYMBOL(md_integrity_add_rdev);
2022 
2023 static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
2024 {
2025         char b[BDEVNAME_SIZE];
2026         struct kobject *ko;
2027         int err;
2028 
2029         /* prevent duplicates */
2030         if (find_rdev(mddev, rdev->bdev->bd_dev))
2031                 return -EEXIST;
2032 
2033         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2034         if (rdev->sectors && (mddev->dev_sectors == 0 ||
2035                         rdev->sectors < mddev->dev_sectors)) {
2036                 if (mddev->pers) {
2037                         /* Cannot change size, so fail
2038                          * If mddev->level <= 0, then we don't care
2039                          * about aligning sizes (e.g. linear)
2040                          */
2041                         if (mddev->level > 0)
2042                                 return -ENOSPC;
2043                 } else
2044                         mddev->dev_sectors = rdev->sectors;
2045         }
2046 
2047         /* Verify rdev->desc_nr is unique.
2048          * If it is -1, assign a free number, else
2049          * check number is not in use
2050          */
2051         rcu_read_lock();
2052         if (rdev->desc_nr < 0) {
2053                 int choice = 0;
2054                 if (mddev->pers)
2055                         choice = mddev->raid_disks;
2056                 while (md_find_rdev_nr_rcu(mddev, choice))
2057                         choice++;
2058                 rdev->desc_nr = choice;
2059         } else {
2060                 if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
2061                         rcu_read_unlock();
2062                         return -EBUSY;
2063                 }
2064         }
2065         rcu_read_unlock();
2066         if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2067                 printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2068                        mdname(mddev), mddev->max_disks);
2069                 return -EBUSY;
2070         }
2071         bdevname(rdev->bdev,b);
2072         strreplace(b, '/', '!');
2073 
2074         rdev->mddev = mddev;
2075         printk(KERN_INFO "md: bind<%s>\n", b);
2076 
2077         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2078                 goto fail;
2079 
2080         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2081         if (sysfs_create_link(&rdev->kobj, ko, "block"))
2082                 /* failure here is OK */;
2083         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2084 
2085         list_add_rcu(&rdev->same_set, &mddev->disks);
2086         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2087 
2088         /* May as well allow recovery to be retried once */
2089         mddev->recovery_disabled++;
2090 
2091         return 0;
2092 
2093  fail:
2094         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2095                b, mdname(mddev));
2096         return err;
2097 }
2098 
2099 static void md_delayed_delete(struct work_struct *ws)
2100 {
2101         struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2102         kobject_del(&rdev->kobj);
2103         kobject_put(&rdev->kobj);
2104 }
2105 
2106 static void unbind_rdev_from_array(struct md_rdev *rdev)
2107 {
2108         char b[BDEVNAME_SIZE];
2109 
2110         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2111         list_del_rcu(&rdev->same_set);
2112         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2113         rdev->mddev = NULL;
2114         sysfs_remove_link(&rdev->kobj, "block");
2115         sysfs_put(rdev->sysfs_state);
2116         rdev->sysfs_state = NULL;
2117         rdev->badblocks.count = 0;
2118         /* We need to delay this, otherwise we can deadlock when
2119          * writing to 'remove' to "dev/state".  We also need
2120          * to delay it due to rcu usage.
2121          */
2122         synchronize_rcu();
2123         INIT_WORK(&rdev->del_work, md_delayed_delete);
2124         kobject_get(&rdev->kobj);
2125         queue_work(md_misc_wq, &rdev->del_work);
2126 }
2127 
2128 /*
2129  * prevent the device from being mounted, repartitioned or
2130  * otherwise reused by a RAID array (or any other kernel
2131  * subsystem), by bd_claiming the device.
2132  */
2133 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2134 {
2135         int err = 0;
2136         struct block_device *bdev;
2137         char b[BDEVNAME_SIZE];
2138 
2139         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2140                                  shared ? (struct md_rdev *)lock_rdev : rdev);
2141         if (IS_ERR(bdev)) {
2142                 printk(KERN_ERR "md: could not open %s.\n",
2143                         __bdevname(dev, b));
2144                 return PTR_ERR(bdev);
2145         }
2146         rdev->bdev = bdev;
2147         return err;
2148 }
2149 
2150 static void unlock_rdev(struct md_rdev *rdev)
2151 {
2152         struct block_device *bdev = rdev->bdev;
2153         rdev->bdev = NULL;
2154         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2155 }
2156 
2157 void md_autodetect_dev(dev_t dev);
2158 
2159 static void export_rdev(struct md_rdev *rdev)
2160 {
2161         char b[BDEVNAME_SIZE];
2162 
2163         printk(KERN_INFO "md: export_rdev(%s)\n",
2164                 bdevname(rdev->bdev,b));
2165         md_rdev_clear(rdev);
2166 #ifndef MODULE
2167         if (test_bit(AutoDetected, &rdev->flags))
2168                 md_autodetect_dev(rdev->bdev->bd_dev);
2169 #endif
2170         unlock_rdev(rdev);
2171         kobject_put(&rdev->kobj);
2172 }
2173 
2174 void md_kick_rdev_from_array(struct md_rdev *rdev)
2175 {
2176         unbind_rdev_from_array(rdev);
2177         export_rdev(rdev);
2178 }
2179 EXPORT_SYMBOL_GPL(md_kick_rdev_from_array);
2180 
2181 static void export_array(struct mddev *mddev)
2182 {
2183         struct md_rdev *rdev;
2184 
2185         while (!list_empty(&mddev->disks)) {
2186                 rdev = list_first_entry(&mddev->disks, struct md_rdev,
2187                                         same_set);
2188                 md_kick_rdev_from_array(rdev);
2189         }
2190         mddev->raid_disks = 0;
2191         mddev->major_version = 0;
2192 }
2193 
2194 static void sync_sbs(struct mddev *mddev, int nospares)
2195 {
2196         /* Update each superblock (in-memory image), but
2197          * if we are allowed to, skip spares which already
2198          * have the right event counter, or have one earlier
2199          * (which would mean they aren't being marked as dirty
2200          * with the rest of the array)
2201          */
2202         struct md_rdev *rdev;
2203         rdev_for_each(rdev, mddev) {
2204                 if (rdev->sb_events == mddev->events ||
2205                     (nospares &&
2206                      rdev->raid_disk < 0 &&
2207                      rdev->sb_events+1 == mddev->events)) {
2208                         /* Don't update this superblock */
2209                         rdev->sb_loaded = 2;
2210                 } else {
2211                         sync_super(mddev, rdev);
2212                         rdev->sb_loaded = 1;
2213                 }
2214         }
2215 }
2216 
2217 void md_update_sb(struct mddev *mddev, int force_change)
2218 {
2219         struct md_rdev *rdev;
2220         int sync_req;
2221         int nospares = 0;
2222         int any_badblocks_changed = 0;
2223 
2224         if (mddev->ro) {
2225                 if (force_change)
2226                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2227                 return;
2228         }
2229 repeat:
2230         /* First make sure individual recovery_offsets are correct */
2231         rdev_for_each(rdev, mddev) {
2232                 if (rdev->raid_disk >= 0 &&
2233                     mddev->delta_disks >= 0 &&
2234                     !test_bit(In_sync, &rdev->flags) &&
2235                     mddev->curr_resync_completed > rdev->recovery_offset)
2236                                 rdev->recovery_offset = mddev->curr_resync_completed;
2237 
2238         }
2239         if (!mddev->persistent) {
2240                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2241                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2242                 if (!mddev->external) {
2243                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2244                         rdev_for_each(rdev, mddev) {
2245                                 if (rdev->badblocks.changed) {
2246                                         rdev->badblocks.changed = 0;
2247                                         md_ack_all_badblocks(&rdev->badblocks);
2248                                         md_error(mddev, rdev);
2249                                 }
2250                                 clear_bit(Blocked, &rdev->flags);
2251                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2252                                 wake_up(&rdev->blocked_wait);
2253                         }
2254                 }
2255                 wake_up(&mddev->sb_wait);
2256                 return;
2257         }
2258 
2259         spin_lock(&mddev->lock);
2260 
2261         mddev->utime = get_seconds();
2262 
2263         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2264                 force_change = 1;
2265         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2266                 /* just a clean<-> dirty transition, possibly leave spares alone,
2267                  * though if events isn't the right even/odd, we will have to do
2268                  * spares after all
2269                  */
2270                 nospares = 1;
2271         if (force_change)
2272                 nospares = 0;
2273         if (mddev->degraded)
2274                 /* If the array is degraded, then skipping spares is both
2275                  * dangerous and fairly pointless.
2276                  * Dangerous because a device that was removed from the array
2277                  * might have a event_count that still looks up-to-date,
2278                  * so it can be re-added without a resync.
2279                  * Pointless because if there are any spares to skip,
2280                  * then a recovery will happen and soon that array won't
2281                  * be degraded any more and the spare can go back to sleep then.
2282                  */
2283                 nospares = 0;
2284 
2285         sync_req = mddev->in_sync;
2286 
2287         /* If this is just a dirty<->clean transition, and the array is clean
2288          * and 'events' is odd, we can roll back to the previous clean state */
2289         if (nospares
2290             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2291             && mddev->can_decrease_events
2292             && mddev->events != 1) {
2293                 mddev->events--;
2294                 mddev->can_decrease_events = 0;
2295         } else {
2296                 /* otherwise we have to go forward and ... */
2297                 mddev->events ++;
2298                 mddev->can_decrease_events = nospares;
2299         }
2300 
2301         /*
2302          * This 64-bit counter should never wrap.
2303          * Either we are in around ~1 trillion A.C., assuming
2304          * 1 reboot per second, or we have a bug...
2305          */
2306         WARN_ON(mddev->events == 0);
2307 
2308         rdev_for_each(rdev, mddev) {
2309                 if (rdev->badblocks.changed)
2310                         any_badblocks_changed++;
2311                 if (test_bit(Faulty, &rdev->flags))
2312                         set_bit(FaultRecorded, &rdev->flags);
2313         }
2314 
2315         sync_sbs(mddev, nospares);
2316         spin_unlock(&mddev->lock);
2317 
2318         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2319                  mdname(mddev), mddev->in_sync);
2320 
2321         bitmap_update_sb(mddev->bitmap);
2322         rdev_for_each(rdev, mddev) {
2323                 char b[BDEVNAME_SIZE];
2324 
2325                 if (rdev->sb_loaded != 1)
2326                         continue; /* no noise on spare devices */
2327 
2328                 if (!test_bit(Faulty, &rdev->flags)) {
2329                         md_super_write(mddev,rdev,
2330                                        rdev->sb_start, rdev->sb_size,
2331                                        rdev->sb_page);
2332                         pr_debug("md: (write) %s's sb offset: %llu\n",
2333                                  bdevname(rdev->bdev, b),
2334                                  (unsigned long long)rdev->sb_start);
2335                         rdev->sb_events = mddev->events;
2336                         if (rdev->badblocks.size) {
2337                                 md_super_write(mddev, rdev,
2338                                                rdev->badblocks.sector,
2339                                                rdev->badblocks.size << 9,
2340                                                rdev->bb_page);
2341                                 rdev->badblocks.size = 0;
2342                         }
2343 
2344                 } else
2345                         pr_debug("md: %s (skipping faulty)\n",
2346                                  bdevname(rdev->bdev, b));
2347 
2348                 if (mddev->level == LEVEL_MULTIPATH)
2349                         /* only need to write one superblock... */
2350                         break;
2351         }
2352         md_super_wait(mddev);
2353         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2354 
2355         spin_lock(&mddev->lock);
2356         if (mddev->in_sync != sync_req ||
2357             test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2358                 /* have to write it out again */
2359                 spin_unlock(&mddev->lock);
2360                 goto repeat;
2361         }
2362         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2363         spin_unlock(&mddev->lock);
2364         wake_up(&mddev->sb_wait);
2365         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2366                 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2367 
2368         rdev_for_each(rdev, mddev) {
2369                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2370                         clear_bit(Blocked, &rdev->flags);
2371 
2372                 if (any_badblocks_changed)
2373                         md_ack_all_badblocks(&rdev->badblocks);
2374                 clear_bit(BlockedBadBlocks, &rdev->flags);
2375                 wake_up(&rdev->blocked_wait);
2376         }
2377 }
2378 EXPORT_SYMBOL(md_update_sb);
2379 
2380 static int add_bound_rdev(struct md_rdev *rdev)
2381 {
2382         struct mddev *mddev = rdev->mddev;
2383         int err = 0;
2384 
2385         if (!mddev->pers->hot_remove_disk) {
2386                 /* If there is hot_add_disk but no hot_remove_disk
2387                  * then added disks for geometry changes,
2388                  * and should be added immediately.
2389                  */
2390                 super_types[mddev->major_version].
2391                         validate_super(mddev, rdev);
2392                 err = mddev->pers->hot_add_disk(mddev, rdev);
2393                 if (err) {
2394                         unbind_rdev_from_array(rdev);
2395                         export_rdev(rdev);
2396                         return err;
2397                 }
2398         }
2399         sysfs_notify_dirent_safe(rdev->sysfs_state);
2400 
2401         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2402         if (mddev->degraded)
2403                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
2404         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2405         md_new_event(mddev);
2406         md_wakeup_thread(mddev->thread);
2407         return 0;
2408 }
2409 
2410 /* words written to sysfs files may, or may not, be \n terminated.
2411  * We want to accept with case. For this we use cmd_match.
2412  */
2413 static int cmd_match(const char *cmd, const char *str)
2414 {
2415         /* See if cmd, written into a sysfs file, matches
2416          * str.  They must either be the same, or cmd can
2417          * have a trailing newline
2418          */
2419         while (*cmd && *str && *cmd == *str) {
2420                 cmd++;
2421                 str++;
2422         }
2423         if (*cmd == '\n')
2424                 cmd++;
2425         if (*str || *cmd)
2426                 return 0;
2427         return 1;
2428 }
2429 
2430 struct rdev_sysfs_entry {
2431         struct attribute attr;
2432         ssize_t (*show)(struct md_rdev *, char *);
2433         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2434 };
2435 
2436 static ssize_t
2437 state_show(struct md_rdev *rdev, char *page)
2438 {
2439         char *sep = "";
2440         size_t len = 0;
2441         unsigned long flags = ACCESS_ONCE(rdev->flags);
2442 
2443         if (test_bit(Faulty, &flags) ||
2444             rdev->badblocks.unacked_exist) {
2445                 len+= sprintf(page+len, "%sfaulty",sep);
2446                 sep = ",";
2447         }
2448         if (test_bit(In_sync, &flags)) {
2449                 len += sprintf(page+len, "%sin_sync",sep);
2450                 sep = ",";
2451         }
2452         if (test_bit(WriteMostly, &flags)) {
2453                 len += sprintf(page+len, "%swrite_mostly",sep);
2454                 sep = ",";
2455         }
2456         if (test_bit(Blocked, &flags) ||
2457             (rdev->badblocks.unacked_exist
2458              && !test_bit(Faulty, &flags))) {
2459                 len += sprintf(page+len, "%sblocked", sep);
2460                 sep = ",";
2461         }
2462         if (!test_bit(Faulty, &flags) &&
2463             !test_bit(In_sync, &flags)) {
2464                 len += sprintf(page+len, "%sspare", sep);
2465                 sep = ",";
2466         }
2467         if (test_bit(WriteErrorSeen, &flags)) {
2468                 len += sprintf(page+len, "%swrite_error", sep);
2469                 sep = ",";
2470         }
2471         if (test_bit(WantReplacement, &flags)) {
2472                 len += sprintf(page+len, "%swant_replacement", sep);
2473                 sep = ",";
2474         }
2475         if (test_bit(Replacement, &flags)) {
2476                 len += sprintf(page+len, "%sreplacement", sep);
2477                 sep = ",";
2478         }
2479 
2480         return len+sprintf(page+len, "\n");
2481 }
2482 
2483 static ssize_t
2484 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2485 {
2486         /* can write
2487          *  faulty  - simulates an error
2488          *  remove  - disconnects the device
2489          *  writemostly - sets write_mostly
2490          *  -writemostly - clears write_mostly
2491          *  blocked - sets the Blocked flags
2492          *  -blocked - clears the Blocked and possibly simulates an error
2493          *  insync - sets Insync providing device isn't active
2494          *  -insync - clear Insync for a device with a slot assigned,
2495          *            so that it gets rebuilt based on bitmap
2496          *  write_error - sets WriteErrorSeen
2497          *  -write_error - clears WriteErrorSeen
2498          */
2499         int err = -EINVAL;
2500         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2501                 md_error(rdev->mddev, rdev);
2502                 if (test_bit(Faulty, &rdev->flags))
2503                         err = 0;
2504                 else
2505                         err = -EBUSY;
2506         } else if (cmd_match(buf, "remove")) {
2507                 if (rdev->raid_disk >= 0)
2508                         err = -EBUSY;
2509                 else {
2510                         struct mddev *mddev = rdev->mddev;
2511                         if (mddev_is_clustered(mddev))
2512                                 md_cluster_ops->remove_disk(mddev, rdev);
2513                         md_kick_rdev_from_array(rdev);
2514                         if (mddev_is_clustered(mddev))
2515                                 md_cluster_ops->metadata_update_start(mddev);
2516                         if (mddev->pers)
2517                                 md_update_sb(mddev, 1);
2518                         md_new_event(mddev);
2519                         if (mddev_is_clustered(mddev))
2520                                 md_cluster_ops->metadata_update_finish(mddev);
2521                         err = 0;
2522                 }
2523         } else if (cmd_match(buf, "writemostly")) {
2524                 set_bit(WriteMostly, &rdev->flags);
2525                 err = 0;
2526         } else if (cmd_match(buf, "-writemostly")) {
2527                 clear_bit(WriteMostly, &rdev->flags);
2528                 err = 0;
2529         } else if (cmd_match(buf, "blocked")) {
2530                 set_bit(Blocked, &rdev->flags);
2531                 err = 0;
2532         } else if (cmd_match(buf, "-blocked")) {
2533                 if (!test_bit(Faulty, &rdev->flags) &&
2534                     rdev->badblocks.unacked_exist) {
2535                         /* metadata handler doesn't understand badblocks,
2536                          * so we need to fail the device
2537                          */
2538                         md_error(rdev->mddev, rdev);
2539                 }
2540                 clear_bit(Blocked, &rdev->flags);
2541                 clear_bit(BlockedBadBlocks, &rdev->flags);
2542                 wake_up(&rdev->blocked_wait);
2543                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2544                 md_wakeup_thread(rdev->mddev->thread);
2545 
2546                 err = 0;
2547         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2548                 set_bit(In_sync, &rdev->flags);
2549                 err = 0;
2550         } else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0) {
2551                 if (rdev->mddev->pers == NULL) {
2552                         clear_bit(In_sync, &rdev->flags);
2553                         rdev->saved_raid_disk = rdev->raid_disk;
2554                         rdev->raid_disk = -1;
2555                         err = 0;
2556                 }
2557         } else if (cmd_match(buf, "write_error")) {
2558                 set_bit(WriteErrorSeen, &rdev->flags);
2559                 err = 0;
2560         } else if (cmd_match(buf, "-write_error")) {
2561                 clear_bit(WriteErrorSeen, &rdev->flags);
2562                 err = 0;
2563         } else if (cmd_match(buf, "want_replacement")) {
2564                 /* Any non-spare device that is not a replacement can
2565                  * become want_replacement at any time, but we then need to
2566                  * check if recovery is needed.
2567                  */
2568                 if (rdev->raid_disk >= 0 &&
2569                     !test_bit(Replacement, &rdev->flags))
2570                         set_bit(WantReplacement, &rdev->flags);
2571                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2572                 md_wakeup_thread(rdev->mddev->thread);
2573                 err = 0;
2574         } else if (cmd_match(buf, "-want_replacement")) {
2575                 /* Clearing 'want_replacement' is always allowed.
2576                  * Once replacements starts it is too late though.
2577                  */
2578                 err = 0;
2579                 clear_bit(WantReplacement, &rdev->flags);
2580         } else if (cmd_match(buf, "replacement")) {
2581                 /* Can only set a device as a replacement when array has not
2582                  * yet been started.  Once running, replacement is automatic
2583                  * from spares, or by assigning 'slot'.
2584                  */
2585                 if (rdev->mddev->pers)
2586                         err = -EBUSY;
2587                 else {
2588                         set_bit(Replacement, &rdev->flags);
2589                         err = 0;
2590                 }
2591         } else if (cmd_match(buf, "-replacement")) {
2592                 /* Similarly, can only clear Replacement before start */
2593                 if (rdev->mddev->pers)
2594                         err = -EBUSY;
2595                 else {
2596                         clear_bit(Replacement, &rdev->flags);
2597                         err = 0;
2598                 }
2599         } else if (cmd_match(buf, "re-add")) {
2600                 if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
2601                         /* clear_bit is performed _after_ all the devices
2602                          * have their local Faulty bit cleared. If any writes
2603                          * happen in the meantime in the local node, they
2604                          * will land in the local bitmap, which will be synced
2605                          * by this node eventually
2606                          */
2607                         if (!mddev_is_clustered(rdev->mddev) ||
2608                             (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
2609                                 clear_bit(Faulty, &rdev->flags);
2610                                 err = add_bound_rdev(rdev);
2611                         }
2612                 } else
2613                         err = -EBUSY;
2614         }
2615         if (!err)
2616                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2617         return err ? err : len;
2618 }
2619 static struct rdev_sysfs_entry rdev_state =
2620 __ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
2621 
2622 static ssize_t
2623 errors_show(struct md_rdev *rdev, char *page)
2624 {
2625         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2626 }
2627 
2628 static ssize_t
2629 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2630 {
2631         unsigned int n;
2632         int rv;
2633 
2634         rv = kstrtouint(buf, 10, &n);
2635         if (rv < 0)
2636                 return rv;
2637         atomic_set(&rdev->corrected_errors, n);
2638         return len;
2639 }
2640 static struct rdev_sysfs_entry rdev_errors =
2641 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2642 
2643 static ssize_t
2644 slot_show(struct md_rdev *rdev, char *page)
2645 {
2646         if (rdev->raid_disk < 0)
2647                 return sprintf(page, "none\n");
2648         else
2649                 return sprintf(page, "%d\n", rdev->raid_disk);
2650 }
2651 
2652 static ssize_t
2653 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2654 {
2655         int slot;
2656         int err;
2657 
2658         if (strncmp(buf, "none", 4)==0)
2659                 slot = -1;
2660         else {
2661                 err = kstrtouint(buf, 10, (unsigned int *)&slot);
2662                 if (err < 0)
2663                         return err;
2664         }
2665         if (rdev->mddev->pers && slot == -1) {
2666                 /* Setting 'slot' on an active array requires also
2667                  * updating the 'rd%d' link, and communicating
2668                  * with the personality with ->hot_*_disk.
2669                  * For now we only support removing
2670                  * failed/spare devices.  This normally happens automatically,
2671                  * but not when the metadata is externally managed.
2672                  */
2673                 if (rdev->raid_disk == -1)
2674                         return -EEXIST;
2675                 /* personality does all needed checks */
2676                 if (rdev->mddev->pers->hot_remove_disk == NULL)
2677                         return -EINVAL;
2678                 clear_bit(Blocked, &rdev->flags);
2679                 remove_and_add_spares(rdev->mddev, rdev);
2680                 if (rdev->raid_disk >= 0)
2681                         return -EBUSY;
2682                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2683                 md_wakeup_thread(rdev->mddev->thread);
2684         } else if (rdev->mddev->pers) {
2685                 /* Activating a spare .. or possibly reactivating
2686                  * if we ever get bitmaps working here.
2687                  */
2688 
2689                 if (rdev->raid_disk != -1)
2690                         return -EBUSY;
2691 
2692                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2693                         return -EBUSY;
2694 
2695                 if (rdev->mddev->pers->hot_add_disk == NULL)
2696                         return -EINVAL;
2697 
2698                 if (slot >= rdev->mddev->raid_disks &&
2699                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2700                         return -ENOSPC;
2701 
2702                 rdev->raid_disk = slot;
2703                 if (test_bit(In_sync, &rdev->flags))
2704                         rdev->saved_raid_disk = slot;
2705                 else
2706                         rdev->saved_raid_disk = -1;
2707                 clear_bit(In_sync, &rdev->flags);
2708                 clear_bit(Bitmap_sync, &rdev->flags);
2709                 err = rdev->mddev->pers->
2710                         hot_add_disk(rdev->mddev, rdev);
2711                 if (err) {
2712                         rdev->raid_disk = -1;
2713                         return err;
2714                 } else
2715                         sysfs_notify_dirent_safe(rdev->sysfs_state);
2716                 if (sysfs_link_rdev(rdev->mddev, rdev))
2717                         /* failure here is OK */;
2718                 /* don't wakeup anyone, leave that to userspace. */
2719         } else {
2720                 if (slot >= rdev->mddev->raid_disks &&
2721                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2722                         return -ENOSPC;
2723                 rdev->raid_disk = slot;
2724                 /* assume it is working */
2725                 clear_bit(Faulty, &rdev->flags);
2726                 clear_bit(WriteMostly, &rdev->flags);
2727                 set_bit(In_sync, &rdev->flags);
2728                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2729         }
2730         return len;
2731 }
2732 
2733 static struct rdev_sysfs_entry rdev_slot =
2734 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2735 
2736 static ssize_t
2737 offset_show(struct md_rdev *rdev, char *page)
2738 {
2739         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2740 }
2741 
2742 static ssize_t
2743 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2744 {
2745         unsigned long long offset;
2746         if (kstrtoull(buf, 10, &offset) < 0)
2747                 return -EINVAL;
2748         if (rdev->mddev->pers && rdev->raid_disk >= 0)
2749                 return -EBUSY;
2750         if (rdev->sectors && rdev->mddev->external)
2751                 /* Must set offset before size, so overlap checks
2752                  * can be sane */
2753                 return -EBUSY;
2754         rdev->data_offset = offset;
2755         rdev->new_data_offset = offset;
2756         return len;
2757 }
2758 
2759 static struct rdev_sysfs_entry rdev_offset =
2760 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2761 
2762 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2763 {
2764         return sprintf(page, "%llu\n",
2765                        (unsigned long long)rdev->new_data_offset);
2766 }
2767 
2768 static ssize_t new_offset_store(struct md_rdev *rdev,
2769                                 const char *buf, size_t len)
2770 {
2771         unsigned long long new_offset;
2772         struct mddev *mddev = rdev->mddev;
2773 
2774         if (kstrtoull(buf, 10, &new_offset) < 0)
2775                 return -EINVAL;
2776 
2777         if (mddev->sync_thread ||
2778             test_bit(MD_RECOVERY_RUNNING,&mddev->recovery))
2779                 return -EBUSY;
2780         if (new_offset == rdev->data_offset)
2781                 /* reset is always permitted */
2782                 ;
2783         else if (new_offset > rdev->data_offset) {
2784                 /* must not push array size beyond rdev_sectors */
2785                 if (new_offset - rdev->data_offset
2786                     + mddev->dev_sectors > rdev->sectors)
2787                                 return -E2BIG;
2788         }
2789         /* Metadata worries about other space details. */
2790 
2791         /* decreasing the offset is inconsistent with a backwards
2792          * reshape.
2793          */
2794         if (new_offset < rdev->data_offset &&
2795             mddev->reshape_backwards)
2796                 return -EINVAL;
2797         /* Increasing offset is inconsistent with forwards
2798          * reshape.  reshape_direction should be set to
2799          * 'backwards' first.
2800          */
2801         if (new_offset > rdev->data_offset &&
2802             !mddev->reshape_backwards)
2803                 return -EINVAL;
2804 
2805         if (mddev->pers && mddev->persistent &&
2806             !super_types[mddev->major_version]
2807             .allow_new_offset(rdev, new_offset))
2808                 return -E2BIG;
2809         rdev->new_data_offset = new_offset;
2810         if (new_offset > rdev->data_offset)
2811                 mddev->reshape_backwards = 1;
2812         else if (new_offset < rdev->data_offset)
2813                 mddev->reshape_backwards = 0;
2814 
2815         return len;
2816 }
2817 static struct rdev_sysfs_entry rdev_new_offset =
2818 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2819 
2820 static ssize_t
2821 rdev_size_show(struct md_rdev *rdev, char *page)
2822 {
2823         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2824 }
2825 
2826 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2827 {
2828         /* check if two start/length pairs overlap */
2829         if (s1+l1 <= s2)
2830                 return 0;
2831         if (s2+l2 <= s1)
2832                 return 0;
2833         return 1;
2834 }
2835 
2836 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2837 {
2838         unsigned long long blocks;
2839         sector_t new;
2840 
2841         if (kstrtoull(buf, 10, &blocks) < 0)
2842                 return -EINVAL;
2843 
2844         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2845                 return -EINVAL; /* sector conversion overflow */
2846 
2847         new = blocks * 2;
2848         if (new != blocks * 2)
2849                 return -EINVAL; /* unsigned long long to sector_t overflow */
2850 
2851         *sectors = new;
2852         return 0;
2853 }
2854 
2855 static ssize_t
2856 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2857 {
2858         struct mddev *my_mddev = rdev->mddev;
2859         sector_t oldsectors = rdev->sectors;
2860         sector_t sectors;
2861 
2862         if (strict_blocks_to_sectors(buf, &sectors) < 0)
2863                 return -EINVAL;
2864         if (rdev->data_offset != rdev->new_data_offset)
2865                 return -EINVAL; /* too confusing */
2866         if (my_mddev->pers && rdev->raid_disk >= 0) {
2867                 if (my_mddev->persistent) {
2868                         sectors = super_types[my_mddev->major_version].
2869                                 rdev_size_change(rdev, sectors);
2870                         if (!sectors)
2871                                 return -EBUSY;
2872                 } else if (!sectors)
2873                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2874                                 rdev->data_offset;
2875                 if (!my_mddev->pers->resize)
2876                         /* Cannot change size for RAID0 or Linear etc */
2877                         return -EINVAL;
2878         }
2879         if (sectors < my_mddev->dev_sectors)
2880                 return -EINVAL; /* component must fit device */
2881 
2882         rdev->sectors = sectors;
2883         if (sectors > oldsectors && my_mddev->external) {
2884                 /* Need to check that all other rdevs with the same
2885                  * ->bdev do not overlap.  'rcu' is sufficient to walk
2886                  * the rdev lists safely.
2887                  * This check does not provide a hard guarantee, it
2888                  * just helps avoid dangerous mistakes.
2889                  */
2890                 struct mddev *mddev;
2891                 int overlap = 0;
2892                 struct list_head *tmp;
2893 
2894                 rcu_read_lock();
2895                 for_each_mddev(mddev, tmp) {
2896                         struct md_rdev *rdev2;
2897 
2898                         rdev_for_each(rdev2, mddev)
2899                                 if (rdev->bdev == rdev2->bdev &&
2900                                     rdev != rdev2 &&
2901                                     overlaps(rdev->data_offset, rdev->sectors,
2902                                              rdev2->data_offset,
2903                                              rdev2->sectors)) {
2904                                         overlap = 1;
2905                                         break;
2906                                 }
2907                         if (overlap) {
2908                                 mddev_put(mddev);
2909                                 break;
2910                         }
2911                 }
2912                 rcu_read_unlock();
2913                 if (overlap) {
2914                         /* Someone else could have slipped in a size
2915                          * change here, but doing so is just silly.
2916                          * We put oldsectors back because we *know* it is
2917                          * safe, and trust userspace not to race with
2918                          * itself
2919                          */
2920                         rdev->sectors = oldsectors;
2921                         return -EBUSY;
2922                 }
2923         }
2924         return len;
2925 }
2926 
2927 static struct rdev_sysfs_entry rdev_size =
2928 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2929 
2930 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
2931 {
2932         unsigned long long recovery_start = rdev->recovery_offset;
2933 
2934         if (test_bit(In_sync, &rdev->flags) ||
2935             recovery_start == MaxSector)
2936                 return sprintf(page, "none\n");
2937 
2938         return sprintf(page, "%llu\n", recovery_start);
2939 }
2940 
2941 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
2942 {
2943         unsigned long long recovery_start;
2944 
2945         if (cmd_match(buf, "none"))
2946                 recovery_start = MaxSector;
2947         else if (kstrtoull(buf, 10, &recovery_start))
2948                 return -EINVAL;
2949 
2950         if (rdev->mddev->pers &&
2951             rdev->raid_disk >= 0)
2952                 return -EBUSY;
2953 
2954         rdev->recovery_offset = recovery_start;
2955         if (recovery_start == MaxSector)
2956                 set_bit(In_sync, &rdev->flags);
2957         else
2958                 clear_bit(In_sync, &rdev->flags);
2959         return len;
2960 }
2961 
2962 static struct rdev_sysfs_entry rdev_recovery_start =
2963 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
2964 
2965 static ssize_t
2966 badblocks_show(struct badblocks *bb, char *page, int unack);
2967 static ssize_t
2968 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
2969 
2970 static ssize_t bb_show(struct md_rdev *rdev, char *page)
2971 {
2972         return badblocks_show(&rdev->badblocks, page, 0);
2973 }
2974 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
2975 {
2976         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
2977         /* Maybe that ack was all we needed */
2978         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
2979                 wake_up(&rdev->blocked_wait);
2980         return rv;
2981 }
2982 static struct rdev_sysfs_entry rdev_bad_blocks =
2983 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
2984 
2985 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
2986 {
2987         return badblocks_show(&rdev->badblocks, page, 1);
2988 }
2989 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
2990 {
2991         return badblocks_store(&rdev->badblocks, page, len, 1);
2992 }
2993 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
2994 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
2995 
2996 static struct attribute *rdev_default_attrs[] = {
2997         &rdev_state.attr,
2998         &rdev_errors.attr,
2999         &rdev_slot.attr,
3000         &rdev_offset.attr,
3001         &rdev_new_offset.attr,
3002         &rdev_size.attr,
3003         &rdev_recovery_start.attr,
3004         &rdev_bad_blocks.attr,
3005         &rdev_unack_bad_blocks.attr,
3006         NULL,
3007 };
3008 static ssize_t
3009 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3010 {
3011         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3012         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3013 
3014         if (!entry->show)
3015                 return -EIO;
3016         if (!rdev->mddev)
3017                 return -EBUSY;
3018         return entry->show(rdev, page);
3019 }
3020 
3021 static ssize_t
3022 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3023               const char *page, size_t length)
3024 {
3025         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3026         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3027         ssize_t rv;
3028         struct mddev *mddev = rdev->mddev;
3029 
3030         if (!entry->store)
3031                 return -EIO;
3032         if (!capable(CAP_SYS_ADMIN))
3033                 return -EACCES;
3034         rv = mddev ? mddev_lock(mddev): -EBUSY;
3035         if (!rv) {
3036                 if (rdev->mddev == NULL)
3037                         rv = -EBUSY;
3038                 else
3039                         rv = entry->store(rdev, page, length);
3040                 mddev_unlock(mddev);
3041         }
3042         return rv;
3043 }
3044 
3045 static void rdev_free(struct kobject *ko)
3046 {
3047         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3048         kfree(rdev);
3049 }
3050 static const struct sysfs_ops rdev_sysfs_ops = {
3051         .show           = rdev_attr_show,
3052         .store          = rdev_attr_store,
3053 };
3054 static struct kobj_type rdev_ktype = {
3055         .release        = rdev_free,
3056         .sysfs_ops      = &rdev_sysfs_ops,
3057         .default_attrs  = rdev_default_attrs,
3058 };
3059 
3060 int md_rdev_init(struct md_rdev *rdev)
3061 {
3062         rdev->desc_nr = -1;
3063         rdev->saved_raid_disk = -1;
3064         rdev->raid_disk = -1;
3065         rdev->flags = 0;
3066         rdev->data_offset = 0;
3067         rdev->new_data_offset = 0;
3068         rdev->sb_events = 0;
3069         rdev->last_read_error.tv_sec  = 0;
3070         rdev->last_read_error.tv_nsec = 0;
3071         rdev->sb_loaded = 0;
3072         rdev->bb_page = NULL;
3073         atomic_set(&rdev->nr_pending, 0);
3074         atomic_set(&rdev->read_errors, 0);
3075         atomic_set(&rdev->corrected_errors, 0);
3076 
3077         INIT_LIST_HEAD(&rdev->same_set);
3078         init_waitqueue_head(&rdev->blocked_wait);
3079 
3080         /* Add space to store bad block list.
3081          * This reserves the space even on arrays where it cannot
3082          * be used - I wonder if that matters
3083          */
3084         rdev->badblocks.count = 0;
3085         rdev->badblocks.shift = -1; /* disabled until explicitly enabled */
3086         rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3087         seqlock_init(&rdev->badblocks.lock);
3088         if (rdev->badblocks.page == NULL)
3089                 return -ENOMEM;
3090 
3091         return 0;
3092 }
3093 EXPORT_SYMBOL_GPL(md_rdev_init);
3094 /*
3095  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3096  *
3097  * mark the device faulty if:
3098  *
3099  *   - the device is nonexistent (zero size)
3100  *   - the device has no valid superblock
3101  *
3102  * a faulty rdev _never_ has rdev->sb set.
3103  */
3104 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3105 {
3106         char b[BDEVNAME_SIZE];
3107         int err;
3108         struct md_rdev *rdev;
3109         sector_t size;
3110 
3111         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3112         if (!rdev) {
3113                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
3114                 return ERR_PTR(-ENOMEM);
3115         }
3116 
3117         err = md_rdev_init(rdev);
3118         if (err)
3119                 goto abort_free;
3120         err = alloc_disk_sb(rdev);
3121         if (err)
3122                 goto abort_free;
3123 
3124         err = lock_rdev(rdev, newdev, super_format == -2);
3125         if (err)
3126                 goto abort_free;
3127 
3128         kobject_init(&rdev->kobj, &rdev_ktype);
3129 
3130         size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3131         if (!size) {
3132                 printk(KERN_WARNING
3133                         "md: %s has zero or unknown size, marking faulty!\n",
3134                         bdevname(rdev->bdev,b));
3135                 err = -EINVAL;
3136                 goto abort_free;
3137         }
3138 
3139         if (super_format >= 0) {
3140                 err = super_types[super_format].
3141                         load_super(rdev, NULL, super_minor);
3142                 if (err == -EINVAL) {
3143                         printk(KERN_WARNING
3144                                 "md: %s does not have a valid v%d.%d "
3145                                "superblock, not importing!\n",
3146                                 bdevname(rdev->bdev,b),
3147                                super_format, super_minor);
3148                         goto abort_free;
3149                 }
3150                 if (err < 0) {
3151                         printk(KERN_WARNING
3152                                 "md: could not read %s's sb, not importing!\n",
3153                                 bdevname(rdev->bdev,b));
3154                         goto abort_free;
3155                 }
3156         }
3157 
3158         return rdev;
3159 
3160 abort_free:
3161         if (rdev->bdev)
3162                 unlock_rdev(rdev);
3163         md_rdev_clear(rdev);
3164         kfree(rdev);
3165         return ERR_PTR(err);
3166 }
3167 
3168 /*
3169  * Check a full RAID array for plausibility
3170  */
3171 
3172 static void analyze_sbs(struct mddev *mddev)
3173 {
3174         int i;
3175         struct md_rdev *rdev, *freshest, *tmp;
3176         char b[BDEVNAME_SIZE];
3177 
3178         freshest = NULL;
3179         rdev_for_each_safe(rdev, tmp, mddev)
3180                 switch (super_types[mddev->major_version].
3181                         load_super(rdev, freshest, mddev->minor_version)) {
3182                 case 1:
3183                         freshest = rdev;
3184                         break;
3185                 case 0:
3186                         break;
3187                 default:
3188                         printk( KERN_ERR \
3189                                 "md: fatal superblock inconsistency in %s"
3190                                 " -- removing from array\n",
3191                                 bdevname(rdev->bdev,b));
3192                         md_kick_rdev_from_array(rdev);
3193                 }
3194 
3195         super_types[mddev->major_version].
3196                 validate_super(mddev, freshest);
3197 
3198         i = 0;
3199         rdev_for_each_safe(rdev, tmp, mddev) {
3200                 if (mddev->max_disks &&
3201                     (rdev->desc_nr >= mddev->max_disks ||
3202                      i > mddev->max_disks)) {
3203                         printk(KERN_WARNING
3204                                "md: %s: %s: only %d devices permitted\n",
3205                                mdname(mddev), bdevname(rdev->bdev, b),
3206                                mddev->max_disks);
3207                         md_kick_rdev_from_array(rdev);
3208                         continue;
3209                 }
3210                 if (rdev != freshest) {
3211                         if (super_types[mddev->major_version].
3212                             validate_super(mddev, rdev)) {
3213                                 printk(KERN_WARNING "md: kicking non-fresh %s"
3214                                         " from array!\n",
3215                                         bdevname(rdev->bdev,b));
3216                                 md_kick_rdev_from_array(rdev);
3217                                 continue;
3218                         }
3219                         /* No device should have a Candidate flag
3220                          * when reading devices
3221                          */
3222                         if (test_bit(Candidate, &rdev->flags)) {
3223                                 pr_info("md: kicking Cluster Candidate %s from array!\n",
3224                                         bdevname(rdev->bdev, b));
3225                                 md_kick_rdev_from_array(rdev);
3226                         }
3227                 }
3228                 if (mddev->level == LEVEL_MULTIPATH) {
3229                         rdev->desc_nr = i++;
3230                         rdev->raid_disk = rdev->desc_nr;
3231                         set_bit(In_sync, &rdev->flags);
3232                 } else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3233                         rdev->raid_disk = -1;
3234                         clear_bit(In_sync, &rdev->flags);
3235                 }
3236         }
3237 }
3238 
3239 /* Read a fixed-point number.
3240  * Numbers in sysfs attributes should be in "standard" units where
3241  * possible, so time should be in seconds.
3242  * However we internally use a a much smaller unit such as
3243  * milliseconds or jiffies.
3244  * This function takes a decimal number with a possible fractional
3245  * component, and produces an integer which is the result of
3246  * multiplying that number by 10^'scale'.
3247  * all without any floating-point arithmetic.
3248  */
3249 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3250 {
3251         unsigned long result = 0;
3252         long decimals = -1;
3253         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3254                 if (*cp == '.')
3255                         decimals = 0;
3256                 else if (decimals < scale) {
3257                         unsigned int value;
3258                         value = *cp - '';
3259                         result = result * 10 + value;
3260                         if (decimals >= 0)
3261                                 decimals++;
3262                 }
3263                 cp++;
3264         }
3265         if (*cp == '\n')
3266                 cp++;
3267         if (*cp)
3268                 return -EINVAL;
3269         if (decimals < 0)
3270                 decimals = 0;
3271         while (decimals < scale) {
3272                 result *= 10;
3273                 decimals ++;
3274         }
3275         *res = result;
3276         return 0;
3277 }
3278 
3279 static void md_safemode_timeout(unsigned long data);
3280 
3281 static ssize_t
3282 safe_delay_show(struct mddev *mddev, char *page)
3283 {
3284         int msec = (mddev->safemode_delay*1000)/HZ;
3285         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3286 }
3287 static ssize_t
3288 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3289 {
3290         unsigned long msec;
3291 
3292         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3293                 return -EINVAL;
3294         if (msec == 0)
3295                 mddev->safemode_delay = 0;
3296         else {
3297                 unsigned long old_delay = mddev->safemode_delay;
3298                 unsigned long new_delay = (msec*HZ)/1000;
3299 
3300                 if (new_delay == 0)
3301                         new_delay = 1;
3302                 mddev->safemode_delay = new_delay;
3303                 if (new_delay < old_delay || old_delay == 0)
3304                         mod_timer(&mddev->safemode_timer, jiffies+1);
3305         }
3306         return len;
3307 }
3308 static struct md_sysfs_entry md_safe_delay =
3309 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3310 
3311 static ssize_t
3312 level_show(struct mddev *mddev, char *page)
3313 {
3314         struct md_personality *p;
3315         int ret;
3316         spin_lock(&mddev->lock);
3317         p = mddev->pers;
3318         if (p)
3319                 ret = sprintf(page, "%s\n", p->name);
3320         else if (mddev->clevel[0])
3321                 ret = sprintf(page, "%s\n", mddev->clevel);
3322         else if (mddev->level != LEVEL_NONE)
3323                 ret = sprintf(page, "%d\n", mddev->level);
3324         else
3325                 ret = 0;
3326         spin_unlock(&mddev->lock);
3327         return ret;
3328 }
3329 
3330 static ssize_t
3331 level_store(struct mddev *mddev, const char *buf, size_t len)
3332 {
3333         char clevel[16];
3334         ssize_t rv;
3335         size_t slen = len;
3336         struct md_personality *pers, *oldpers;
3337         long level;
3338         void *priv, *oldpriv;
3339         struct md_rdev *rdev;
3340 
3341         if (slen == 0 || slen >= sizeof(clevel))
3342                 return -EINVAL;
3343 
3344         rv = mddev_lock(mddev);
3345         if (rv)
3346                 return rv;
3347 
3348         if (mddev->pers == NULL) {
3349                 strncpy(mddev->clevel, buf, slen);
3350                 if (mddev->clevel[slen-1] == '\n')
3351                         slen--;
3352                 mddev->clevel[slen] = 0;
3353                 mddev->level = LEVEL_NONE;
3354                 rv = len;
3355                 goto out_unlock;
3356         }
3357         rv = -EROFS;
3358         if (mddev->ro)
3359                 goto out_unlock;
3360 
3361         /* request to change the personality.  Need to ensure:
3362          *  - array is not engaged in resync/recovery/reshape
3363          *  - old personality can be suspended
3364          *  - new personality will access other array.
3365          */
3366 
3367         rv = -EBUSY;
3368         if (mddev->sync_thread ||
3369             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3370             mddev->reshape_position != MaxSector ||
3371             mddev->sysfs_active)
3372                 goto out_unlock;
3373 
3374         rv = -EINVAL;
3375         if (!mddev->pers->quiesce) {
3376                 printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3377                        mdname(mddev), mddev->pers->name);
3378                 goto out_unlock;
3379         }
3380 
3381         /* Now find the new personality */
3382         strncpy(clevel, buf, slen);
3383         if (clevel[slen-1] == '\n')
3384                 slen--;
3385         clevel[slen] = 0;
3386         if (kstrtol(clevel, 10, &level))
3387                 level = LEVEL_NONE;
3388 
3389         if (request_module("md-%s", clevel) != 0)
3390                 request_module("md-level-%s", clevel);
3391         spin_lock(&pers_lock);
3392         pers = find_pers(level, clevel);
3393         if (!pers || !try_module_get(pers->owner)) {
3394                 spin_unlock(&pers_lock);
3395                 printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3396                 rv = -EINVAL;
3397                 goto out_unlock;
3398         }
3399         spin_unlock(&pers_lock);
3400 
3401         if (pers == mddev->pers) {
3402                 /* Nothing to do! */
3403                 module_put(pers->owner);
3404                 rv = len;
3405                 goto out_unlock;
3406         }
3407         if (!pers->takeover) {
3408                 module_put(pers->owner);
3409                 printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3410                        mdname(mddev), clevel);
3411                 rv = -EINVAL;
3412                 goto out_unlock;
3413         }
3414 
3415         rdev_for_each(rdev, mddev)
3416                 rdev->new_raid_disk = rdev->raid_disk;
3417 
3418         /* ->takeover must set new_* and/or delta_disks
3419          * if it succeeds, and may set them when it fails.
3420          */
3421         priv = pers->takeover(mddev);
3422         if (IS_ERR(priv)) {
3423                 mddev->new_level = mddev->level;
3424                 mddev->new_layout = mddev->layout;
3425                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3426                 mddev->raid_disks -= mddev->delta_disks;
3427                 mddev->delta_disks = 0;
3428                 mddev->reshape_backwards = 0;
3429                 module_put(pers->owner);
3430                 printk(KERN_WARNING "md: %s: %s would not accept array\n",
3431                        mdname(mddev), clevel);
3432                 rv = PTR_ERR(priv);
3433                 goto out_unlock;
3434         }
3435 
3436         /* Looks like we have a winner */
3437         mddev_suspend(mddev);
3438         mddev_detach(mddev);
3439 
3440         spin_lock(&mddev->lock);
3441         oldpers = mddev->pers;
3442         oldpriv = mddev->private;
3443         mddev->pers = pers;
3444         mddev->private = priv;
3445         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3446         mddev->level = mddev->new_level;
3447         mddev->layout = mddev->new_layout;
3448         mddev->chunk_sectors = mddev->new_chunk_sectors;
3449         mddev->delta_disks = 0;
3450         mddev->reshape_backwards = 0;
3451         mddev->degraded = 0;
3452         spin_unlock(&mddev->lock);
3453 
3454         if (oldpers->sync_request == NULL &&
3455             mddev->external) {
3456                 /* We are converting from a no-redundancy array
3457                  * to a redundancy array and metadata is managed
3458                  * externally so we need to be sure that writes
3459                  * won't block due to a need to transition
3460                  *      clean->dirty
3461                  * until external management is started.
3462                  */
3463                 mddev->in_sync = 0;
3464                 mddev->safemode_delay = 0;
3465                 mddev->safemode = 0;
3466         }
3467 
3468         oldpers->free(mddev, oldpriv);
3469 
3470         if (oldpers->sync_request == NULL &&
3471             pers->sync_request != NULL) {
3472                 /* need to add the md_redundancy_group */
3473                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3474                         printk(KERN_WARNING
3475                                "md: cannot register extra attributes for %s\n",
3476                                mdname(mddev));
3477                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3478         }
3479         if (oldpers->sync_request != NULL &&
3480             pers->sync_request == NULL) {
3481                 /* need to remove the md_redundancy_group */
3482                 if (mddev->to_remove == NULL)
3483                         mddev->to_remove = &md_redundancy_group;
3484         }
3485 
3486         rdev_for_each(rdev, mddev) {
3487                 if (rdev->raid_disk < 0)
3488                         continue;
3489                 if (rdev->new_raid_disk >= mddev->raid_disks)
3490                         rdev->new_raid_disk = -1;
3491                 if (rdev->new_raid_disk == rdev->raid_disk)
3492                         continue;
3493                 sysfs_unlink_rdev(mddev, rdev);
3494         }
3495         rdev_for_each(rdev, mddev) {
3496                 if (rdev->raid_disk < 0)
3497                         continue;
3498                 if (rdev->new_raid_disk == rdev->raid_disk)
3499                         continue;
3500                 rdev->raid_disk = rdev->new_raid_disk;
3501                 if (rdev->raid_disk < 0)
3502                         clear_bit(In_sync, &rdev->flags);
3503                 else {
3504                         if (sysfs_link_rdev(mddev, rdev))
3505                                 printk(KERN_WARNING "md: cannot register rd%d"
3506                                        " for %s after level change\n",
3507                                        rdev->raid_disk, mdname(mddev));
3508                 }
3509         }
3510 
3511         if (pers->sync_request == NULL) {
3512                 /* this is now an array without redundancy, so
3513                  * it must always be in_sync
3514                  */
3515                 mddev->in_sync = 1;
3516                 del_timer_sync(&mddev->safemode_timer);
3517         }
3518         blk_set_stacking_limits(&mddev->queue->limits);
3519         pers->run(mddev);
3520         set_bit(MD_CHANGE_DEVS, &mddev->flags);
3521         mddev_resume(mddev);
3522         if (!mddev->thread)
3523                 md_update_sb(mddev, 1);
3524         sysfs_notify(&mddev->kobj, NULL, "level");
3525         md_new_event(mddev);
3526         rv = len;
3527 out_unlock:
3528         mddev_unlock(mddev);
3529         return rv;
3530 }
3531 
3532 static struct md_sysfs_entry md_level =
3533 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3534 
3535 static ssize_t
3536 layout_show(struct mddev *mddev, char *page)
3537 {
3538         /* just a number, not meaningful for all levels */
3539         if (mddev->reshape_position != MaxSector &&
3540             mddev->layout != mddev->new_layout)
3541                 return sprintf(page, "%d (%d)\n",
3542                                mddev->new_layout, mddev->layout);
3543         return sprintf(page, "%d\n", mddev->layout);
3544 }
3545 
3546 static ssize_t
3547 layout_store(struct mddev *mddev, const char *buf, size_t len)
3548 {
3549         unsigned int n;
3550         int err;
3551 
3552         err = kstrtouint(buf, 10, &n);
3553         if (err < 0)
3554                 return err;
3555         err = mddev_lock(mddev);
3556         if (err)
3557                 return err;
3558 
3559         if (mddev->pers) {
3560                 if (mddev->pers->check_reshape == NULL)
3561                         err = -EBUSY;
3562                 else if (mddev->ro)
3563                         err = -EROFS;
3564                 else {
3565                         mddev->new_layout = n;
3566                         err = mddev->pers->check_reshape(mddev);
3567                         if (err)
3568                                 mddev->new_layout = mddev->layout;
3569                 }
3570         } else {
3571                 mddev->new_layout = n;
3572                 if (mddev->reshape_position == MaxSector)
3573                         mddev->layout = n;
3574         }
3575         mddev_unlock(mddev);
3576         return err ?: len;
3577 }
3578 static struct md_sysfs_entry md_layout =
3579 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3580 
3581 static ssize_t
3582 raid_disks_show(struct mddev *mddev, char *page)
3583 {
3584         if (mddev->raid_disks == 0)
3585                 return 0;
3586         if (mddev->reshape_position != MaxSector &&
3587             mddev->delta_disks != 0)
3588                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3589                                mddev->raid_disks - mddev->delta_disks);
3590         return sprintf(page, "%d\n", mddev->raid_disks);
3591 }
3592 
3593 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3594 
3595 static ssize_t
3596 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3597 {
3598         unsigned int n;
3599         int err;
3600 
3601         err = kstrtouint(buf, 10, &n);
3602         if (err < 0)
3603                 return err;
3604 
3605         err = mddev_lock(mddev);
3606         if (err)
3607                 return err;
3608         if (mddev->pers)
3609                 err = update_raid_disks(mddev, n);
3610         else if (mddev->reshape_position != MaxSector) {
3611                 struct md_rdev *rdev;
3612                 int olddisks = mddev->raid_disks - mddev->delta_disks;
3613 
3614                 err = -EINVAL;
3615                 rdev_for_each(rdev, mddev) {
3616                         if (olddisks < n &&
3617                             rdev->data_offset < rdev->new_data_offset)
3618                                 goto out_unlock;
3619                         if (olddisks > n &&
3620                             rdev->data_offset > rdev->new_data_offset)
3621                                 goto out_unlock;
3622                 }
3623                 err = 0;
3624                 mddev->delta_disks = n - olddisks;
3625                 mddev->raid_disks = n;
3626                 mddev->reshape_backwards = (mddev->delta_disks < 0);
3627         } else
3628                 mddev->raid_disks = n;
3629 out_unlock:
3630         mddev_unlock(mddev);
3631         return err ? err : len;
3632 }
3633 static struct md_sysfs_entry md_raid_disks =
3634 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3635 
3636 static ssize_t
3637 chunk_size_show(struct mddev *mddev, char *page)
3638 {
3639         if (mddev->reshape_position != MaxSector &&
3640             mddev->chunk_sectors != mddev->new_chunk_sectors)
3641                 return sprintf(page, "%d (%d)\n",
3642                                mddev->new_chunk_sectors << 9,
3643                                mddev->chunk_sectors << 9);
3644         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3645 }
3646 
3647 static ssize_t
3648 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3649 {
3650         unsigned long n;
3651         int err;
3652 
3653         err = kstrtoul(buf, 10, &n);
3654         if (err < 0)
3655                 return err;
3656 
3657         err = mddev_lock(mddev);
3658         if (err)
3659                 return err;
3660         if (mddev->pers) {
3661                 if (mddev->pers->check_reshape == NULL)
3662                         err = -EBUSY;
3663                 else if (mddev->ro)
3664                         err = -EROFS;
3665                 else {
3666                         mddev->new_chunk_sectors = n >> 9;
3667                         err = mddev->pers->check_reshape(mddev);
3668                         if (err)
3669                                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3670                 }
3671         } else {
3672                 mddev->new_chunk_sectors = n >> 9;
3673                 if (mddev->reshape_position == MaxSector)
3674                         mddev->chunk_sectors = n >> 9;
3675         }
3676         mddev_unlock(mddev);
3677         return err ?: len;
3678 }
3679 static struct md_sysfs_entry md_chunk_size =
3680 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3681 
3682 static ssize_t
3683 resync_start_show(struct mddev *mddev, char *page)
3684 {
3685         if (mddev->recovery_cp == MaxSector)
3686                 return sprintf(page, "none\n");
3687         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3688 }
3689 
3690 static ssize_t
3691 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3692 {
3693         unsigned long long n;
3694         int err;
3695 
3696         if (cmd_match(buf, "none"))
3697                 n = MaxSector;
3698         else {
3699                 err = kstrtoull(buf, 10, &n);
3700                 if (err < 0)
3701                         return err;
3702                 if (n != (sector_t)n)
3703                         return -EINVAL;
3704         }
3705 
3706         err = mddev_lock(mddev);
3707         if (err)
3708                 return err;
3709         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3710                 err = -EBUSY;
3711 
3712         if (!err) {
3713                 mddev->recovery_cp = n;
3714                 if (mddev->pers)
3715                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3716         }
3717         mddev_unlock(mddev);
3718         return err ?: len;
3719 }
3720 static struct md_sysfs_entry md_resync_start =
3721 __ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
3722                 resync_start_show, resync_start_store);
3723 
3724 /*
3725  * The array state can be:
3726  *
3727  * clear
3728  *     No devices, no size, no level
3729  *     Equivalent to STOP_ARRAY ioctl
3730  * inactive
3731  *     May have some settings, but array is not active
3732  *        all IO results in error
3733  *     When written, doesn't tear down array, but just stops it
3734  * suspended (not supported yet)
3735  *     All IO requests will block. The array can be reconfigured.
3736  *     Writing this, if accepted, will block until array is quiescent
3737  * readonly
3738  *     no resync can happen.  no superblocks get written.
3739  *     write requests fail
3740  * read-auto
3741  *     like readonly, but behaves like 'clean' on a write request.
3742  *
3743  * clean - no pending writes, but otherwise active.
3744  *     When written to inactive array, starts without resync
3745  *     If a write request arrives then
3746  *       if metadata is known, mark 'dirty' and switch to 'active'.
3747  *       if not known, block and switch to write-pending
3748  *     If written to an active array that has pending writes, then fails.
3749  * active
3750  *     fully active: IO and resync can be happening.
3751  *     When written to inactive array, starts with resync
3752  *
3753  * write-pending
3754  *     clean, but writes are blocked waiting for 'active' to be written.
3755  *
3756  * active-idle
3757  *     like active, but no writes have been seen for a while (100msec).
3758  *
3759  */
3760 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3761                    write_pending, active_idle, bad_word};
3762 static char *array_states[] = {
3763         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3764         "write-pending", "active-idle", NULL };
3765 
3766 static int match_word(const char *word, char **list)
3767 {
3768         int n;
3769         for (n=0; list[n]; n++)
3770                 if (cmd_match(word, list[n]))
3771                         break;
3772         return n;
3773 }
3774 
3775 static ssize_t
3776 array_state_show(struct mddev *mddev, char *page)
3777 {
3778         enum array_state st = inactive;
3779 
3780         if (mddev->pers)
3781                 switch(mddev->ro) {
3782                 case 1:
3783                         st = readonly;
3784                         break;
3785                 case 2:
3786                         st = read_auto;
3787                         break;
3788                 case 0:
3789                         if (mddev->in_sync)
3790                                 st = clean;
3791                         else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3792                                 st = write_pending;
3793                         else if (mddev->safemode)
3794                                 st = active_idle;
3795                         else
3796                                 st = active;
3797                 }
3798         else {
3799                 if (list_empty(&mddev->disks) &&
3800                     mddev->raid_disks == 0 &&
3801                     mddev->dev_sectors == 0)
3802                         st = clear;
3803                 else
3804                         st = inactive;
3805         }
3806         return sprintf(page, "%s\n", array_states[st]);
3807 }
3808 
3809 static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
3810 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
3811 static int do_md_run(struct mddev *mddev);
3812 static int restart_array(struct mddev *mddev);
3813 
3814 static ssize_t
3815 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3816 {
3817         int err;
3818         enum array_state st = match_word(buf, array_states);
3819 
3820         if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) {
3821                 /* don't take reconfig_mutex when toggling between
3822                  * clean and active
3823                  */
3824                 spin_lock(&mddev->lock);
3825                 if (st == active) {
3826                         restart_array(mddev);
3827                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3828                         wake_up(&mddev->sb_wait);
3829                         err = 0;
3830                 } else /* st == clean */ {
3831                         restart_array(mddev);
3832                         if (atomic_read(&mddev->writes_pending) == 0) {
3833                                 if (mddev->in_sync == 0) {
3834                                         mddev->in_sync = 1;
3835                                         if (mddev->safemode == 1)
3836                                                 mddev->safemode = 0;
3837                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3838                                 }
3839                                 err = 0;
3840                         } else
3841                                 err = -EBUSY;
3842                 }
3843                 spin_unlock(&mddev->lock);
3844                 return err ?: len;
3845         }
3846         err = mddev_lock(mddev);
3847         if (err)
3848                 return err;
3849         err = -EINVAL;
3850         switch(st) {
3851         case bad_word:
3852                 break;
3853         case clear:
3854                 /* stopping an active array */
3855                 err = do_md_stop(mddev, 0, NULL);
3856                 break;
3857         case inactive:
3858                 /* stopping an active array */
3859                 if (mddev->pers)
3860                         err = do_md_stop(mddev, 2, NULL);
3861                 else
3862                         err = 0; /* already inactive */
3863                 break;
3864         case suspended:
3865                 break; /* not supported yet */
3866         case readonly:
3867                 if (mddev->pers)
3868                         err = md_set_readonly(mddev, NULL);
3869                 else {
3870                         mddev->ro = 1;
3871                         set_disk_ro(mddev->gendisk, 1);
3872                         err = do_md_run(mddev);
3873                 }
3874                 break;
3875         case read_auto:
3876                 if (mddev->pers) {
3877                         if (mddev->ro == 0)
3878                                 err = md_set_readonly(mddev, NULL);
3879                         else if (mddev->ro == 1)
3880                                 err = restart_array(mddev);
3881                         if (err == 0) {
3882                                 mddev->ro = 2;
3883                                 set_disk_ro(mddev->gendisk, 0);
3884                         }
3885                 } else {
3886                         mddev->ro = 2;
3887                         err = do_md_run(mddev);
3888                 }
3889                 break;
3890         case clean:
3891                 if (mddev->pers) {
3892                         restart_array(mddev);
3893                         spin_lock(&mddev->lock);
3894                         if (atomic_read(&mddev->writes_pending) == 0) {
3895                                 if (mddev->in_sync == 0) {
3896                                         mddev->in_sync = 1;
3897                                         if (mddev->safemode == 1)
3898                                                 mddev->safemode = 0;
3899                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3900                                 }
3901                                 err = 0;
3902                         } else
3903                                 err = -EBUSY;
3904                         spin_unlock(&mddev->lock);
3905                 } else
3906                         err = -EINVAL;
3907                 break;
3908         case active:
3909                 if (mddev->pers) {
3910                         restart_array(mddev);
3911                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3912                         wake_up(&mddev->sb_wait);
3913                         err = 0;
3914                 } else {
3915                         mddev->ro = 0;
3916                         set_disk_ro(mddev->gendisk, 0);
3917                         err = do_md_run(mddev);
3918                 }
3919                 break;
3920         case write_pending:
3921         case active_idle:
3922                 /* these cannot be set */
3923                 break;
3924         }
3925 
3926         if (!err) {
3927                 if (mddev->hold_active == UNTIL_IOCTL)
3928                         mddev->hold_active = 0;
3929                 sysfs_notify_dirent_safe(mddev->sysfs_state);
3930         }
3931         mddev_unlock(mddev);
3932         return err ?: len;
3933 }
3934 static struct md_sysfs_entry md_array_state =
3935 __ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3936 
3937 static ssize_t
3938 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
3939         return sprintf(page, "%d\n",
3940                        atomic_read(&mddev->max_corr_read_errors));
3941 }
3942 
3943 static ssize_t
3944 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
3945 {
3946         unsigned int n;
3947         int rv;
3948 
3949         rv = kstrtouint(buf, 10, &n);
3950         if (rv < 0)
3951                 return rv;
3952         atomic_set(&mddev->max_corr_read_errors, n);
3953         return len;
3954 }
3955 
3956 static struct md_sysfs_entry max_corr_read_errors =
3957 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3958         max_corrected_read_errors_store);
3959 
3960 static ssize_t
3961 null_show(struct mddev *mddev, char *page)
3962 {
3963         return -EINVAL;
3964 }
3965 
3966 static ssize_t
3967 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
3968 {
3969         /* buf must be %d:%d\n? giving major and minor numbers */
3970         /* The new device is added to the array.
3971          * If the array has a persistent superblock, we read the
3972          * superblock to initialise info and check validity.
3973          * Otherwise, only checking done is that in bind_rdev_to_array,
3974          * which mainly checks size.
3975          */
3976         char *e;
3977         int major = simple_strtoul(buf, &e, 10);
3978         int minor;
3979         dev_t dev;
3980         struct md_rdev *rdev;
3981         int err;
3982 
3983         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3984                 return -EINVAL;
3985         minor = simple_strtoul(e+1, &e, 10);
3986         if (*e && *e != '\n')
3987                 return -EINVAL;
3988         dev = MKDEV(major, minor);
3989         if (major != MAJOR(dev) ||
3990             minor != MINOR(dev))
3991                 return -EOVERFLOW;
3992 
3993         flush_workqueue(md_misc_wq);
3994 
3995         err = mddev_lock(mddev);
3996         if (err)
3997                 return err;
3998         if (mddev->persistent) {
3999                 rdev = md_import_device(dev, mddev->major_version,
4000                                         mddev->minor_version);
4001                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4002                         struct md_rdev *rdev0
4003                                 = list_entry(mddev->disks.next,
4004                                              struct md_rdev, same_set);
4005                         err = super_types[mddev->major_version]
4006                                 .load_super(rdev, rdev0, mddev->minor_version);
4007                         if (err < 0)
4008                                 goto out;
4009                 }
4010         } else if (mddev->external)
4011                 rdev = md_import_device(dev, -2, -1);
4012         else
4013                 rdev = md_import_device(dev, -1, -1);
4014 
4015         if (IS_ERR(rdev)) {
4016                 mddev_unlock(mddev);
4017                 return PTR_ERR(rdev);
4018         }
4019         err = bind_rdev_to_array(rdev, mddev);
4020  out:
4021         if (err)
4022                 export_rdev(rdev);
4023         mddev_unlock(mddev);
4024         return err ? err : len;
4025 }
4026 
4027 static struct md_sysfs_entry md_new_device =
4028 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4029 
4030 static ssize_t
4031 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4032 {
4033         char *end;
4034         unsigned long chunk, end_chunk;
4035         int err;
4036 
4037         err = mddev_lock(mddev);
4038         if (err)
4039                 return err;
4040         if (!mddev->bitmap)
4041                 goto out;
4042         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4043         while (*buf) {
4044                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4045                 if (buf == end) break;
4046                 if (*end == '-') { /* range */
4047                         buf = end + 1;
4048                         end_chunk = simple_strtoul(buf, &end, 0);
4049                         if (buf == end) break;
4050                 }
4051                 if (*end && !isspace(*end)) break;
4052                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4053                 buf = skip_spaces(end);
4054         }
4055         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4056 out:
4057         mddev_unlock(mddev);
4058         return len;
4059 }
4060 
4061 static struct md_sysfs_entry md_bitmap =
4062 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4063 
4064 static ssize_t
4065 size_show(struct mddev *mddev, char *page)
4066 {
4067         return sprintf(page, "%llu\n",
4068                 (unsigned long long)mddev->dev_sectors / 2);
4069 }
4070 
4071 static int update_size(struct mddev *mddev, sector_t num_sectors);
4072 
4073 static ssize_t
4074 size_store(struct mddev *mddev, const char *buf, size_t len)
4075 {
4076         /* If array is inactive, we can reduce the component size, but
4077          * not increase it (except from 0).
4078          * If array is active, we can try an on-line resize
4079          */
4080         sector_t sectors;
4081         int err = strict_blocks_to_sectors(buf, &sectors);
4082 
4083         if (err < 0)
4084                 return err;
4085         err = mddev_lock(mddev);
4086         if (err)
4087                 return err;
4088         if (mddev->pers) {
4089                 if (mddev_is_clustered(mddev))
4090                         md_cluster_ops->metadata_update_start(mddev);
4091                 err = update_size(mddev, sectors);
4092                 md_update_sb(mddev, 1);
4093                 if (mddev_is_clustered(mddev))
4094                         md_cluster_ops->metadata_update_finish(mddev);
4095         } else {
4096                 if (mddev->dev_sectors == 0 ||
4097                     mddev->dev_sectors > sectors)
4098                         mddev->dev_sectors = sectors;
4099                 else
4100                         err = -ENOSPC;
4101         }
4102         mddev_unlock(mddev);
4103         return err ? err : len;
4104 }
4105 
4106 static struct md_sysfs_entry md_size =
4107 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4108 
4109 /* Metadata version.
4110  * This is one of
4111  *   'none' for arrays with no metadata (good luck...)
4112  *   'external' for arrays with externally managed metadata,
4113  * or N.M for internally known formats
4114  */
4115 static ssize_t
4116 metadata_show(struct mddev *mddev, char *page)
4117 {
4118         if (mddev->persistent)
4119                 return sprintf(page, "%d.%d\n",
4120                                mddev->major_version, mddev->minor_version);
4121         else if (mddev->external)
4122                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4123         else
4124                 return sprintf(page, "none\n");
4125 }
4126 
4127 static ssize_t
4128 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4129 {
4130         int major, minor;
4131         char *e;
4132         int err;
4133         /* Changing the details of 'external' metadata is
4134          * always permitted.  Otherwise there must be
4135          * no devices attached to the array.
4136          */
4137 
4138         err = mddev_lock(mddev);
4139         if (err)
4140                 return err;
4141         err = -EBUSY;
4142         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4143                 ;
4144         else if (!list_empty(&mddev->disks))
4145                 goto out_unlock;
4146 
4147         err = 0;
4148         if (cmd_match(buf, "none")) {
4149                 mddev->persistent = 0;
4150                 mddev->external = 0;
4151                 mddev->major_version = 0;
4152                 mddev->minor_version = 90;
4153                 goto out_unlock;
4154         }
4155         if (strncmp(buf, "external:", 9) == 0) {
4156                 size_t namelen = len-9;
4157                 if (namelen >= sizeof(mddev->metadata_type))
4158                         namelen = sizeof(mddev->metadata_type)-1;
4159                 strncpy(mddev->metadata_type, buf+9, namelen);
4160                 mddev->metadata_type[namelen] = 0;
4161                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4162                         mddev->metadata_type[--namelen] = 0;
4163                 mddev->persistent = 0;
4164                 mddev->external = 1;
4165                 mddev->major_version = 0;
4166                 mddev->minor_version = 90;
4167                 goto out_unlock;
4168         }
4169         major = simple_strtoul(buf, &e, 10);
4170         err = -EINVAL;
4171         if (e==buf || *e != '.')
4172                 goto out_unlock;
4173         buf = e+1;
4174         minor = simple_strtoul(buf, &e, 10);
4175         if (e==buf || (*e && *e != '\n') )
4176                 goto out_unlock;
4177         err = -ENOENT;
4178         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4179                 goto out_unlock;
4180         mddev->major_version = major;
4181         mddev->minor_version = minor;
4182         mddev->persistent = 1;
4183         mddev->external = 0;
4184         err = 0;
4185 out_unlock:
4186         mddev_unlock(mddev);
4187         return err ?: len;
4188 }
4189 
4190 static struct md_sysfs_entry md_metadata =
4191 __ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4192 
4193 static ssize_t
4194 action_show(struct mddev *mddev, char *page)
4195 {
4196         char *type = "idle";
4197         unsigned long recovery = mddev->recovery;
4198         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
4199                 type = "frozen";
4200         else if (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
4201             (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
4202                 if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
4203                         type = "reshape";
4204                 else if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
4205                         if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
4206                                 type = "resync";
4207                         else if (test_bit(MD_RECOVERY_CHECK, &recovery))
4208                                 type = "check";
4209                         else
4210                                 type = "repair";
4211                 } else if (test_bit(MD_RECOVERY_RECOVER, &recovery))
4212                         type = "recover";
4213         }
4214         return sprintf(page, "%s\n", type);
4215 }
4216 
4217 static ssize_t
4218 action_store(struct mddev *mddev, const char *page, size_t len)
4219 {
4220         if (!mddev->pers || !mddev->pers->sync_request)
4221                 return -EINVAL;
4222 
4223 
4224         if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4225                 if (cmd_match(page, "frozen"))
4226                         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4227                 else
4228                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4229                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
4230                     mddev_lock(mddev) == 0) {
4231                         flush_workqueue(md_misc_wq);
4232                         if (mddev->sync_thread) {
4233                                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4234                                 md_reap_sync_thread(mddev);
4235                         }
4236                         mddev_unlock(mddev);
4237                 }
4238         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4239                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4240                 return -EBUSY;
4241         else if (cmd_match(page, "resync"))
4242                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4243         else if (cmd_match(page, "recover")) {
4244                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4245                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4246         } else if (cmd_match(page, "reshape")) {
4247                 int err;
4248                 if (mddev->pers->start_reshape == NULL)
4249                         return -EINVAL;
4250                 err = mddev_lock(mddev);
4251                 if (!err) {
4252                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4253                         err = mddev->pers->start_reshape(mddev);
4254                         mddev_unlock(mddev);
4255                 }
4256                 if (err)
4257                         return err;
4258                 sysfs_notify(&mddev->kobj, NULL, "degraded");
4259         } else {
4260                 if (cmd_match(page, "check"))
4261                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4262                 else if (!cmd_match(page, "repair"))
4263                         return -EINVAL;
4264                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4265                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4266                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4267         }
4268         if (mddev->ro == 2) {
4269                 /* A write to sync_action is enough to justify
4270                  * canceling read-auto mode
4271                  */
4272                 mddev->ro = 0;
4273                 md_wakeup_thread(mddev->sync_thread);
4274         }
4275         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4276         md_wakeup_thread(mddev->thread);
4277         sysfs_notify_dirent_safe(mddev->sysfs_action);
4278         return len;
4279 }
4280 
4281 static struct md_sysfs_entry md_scan_mode =
4282 __ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4283 
4284 static ssize_t
4285 last_sync_action_show(struct mddev *mddev, char *page)
4286 {
4287         return sprintf(page, "%s\n", mddev->last_sync_action);
4288 }
4289 
4290 static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
4291 
4292 static ssize_t
4293 mismatch_cnt_show(struct mddev *mddev, char *page)
4294 {
4295         return sprintf(page, "%llu\n",
4296                        (unsigned long long)
4297                        atomic64_read(&mddev->resync_mismatches));
4298 }
4299 
4300 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4301 
4302 static ssize_t
4303 sync_min_show(struct mddev *mddev, char *page)
4304 {
4305         return sprintf(page, "%d (%s)\n", speed_min(mddev),
4306                        mddev->sync_speed_min ? "local": "system");
4307 }
4308 
4309 static ssize_t
4310 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4311 {
4312         unsigned int min;
4313         int rv;
4314 
4315         if (strncmp(buf, "system", 6)==0) {
4316                 min = 0;
4317         } else {
4318                 rv = kstrtouint(buf, 10, &min);
4319                 if (rv < 0)
4320                         return rv;
4321                 if (min == 0)
4322                         return -EINVAL;
4323         }
4324         mddev->sync_speed_min = min;
4325         return len;
4326 }
4327 
4328 static struct md_sysfs_entry md_sync_min =
4329 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4330 
4331 static ssize_t
4332 sync_max_show(struct mddev *mddev, char *page)
4333 {
4334         return sprintf(page, "%d (%s)\n", speed_max(mddev),
4335                        mddev->sync_speed_max ? "local": "system");
4336 }
4337 
4338 static ssize_t
4339 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4340 {
4341         unsigned int max;
4342         int rv;
4343 
4344         if (strncmp(buf, "system", 6)==0) {
4345                 max = 0;
4346         } else {
4347                 rv = kstrtouint(buf, 10, &max);
4348                 if (rv < 0)
4349                         return rv;
4350                 if (max == 0)
4351                         return -EINVAL;
4352         }
4353         mddev->sync_speed_max = max;
4354         return len;
4355 }
4356 
4357 static struct md_sysfs_entry md_sync_max =
4358 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4359 
4360 static ssize_t
4361 degraded_show(struct mddev *mddev, char *page)
4362 {
4363         return sprintf(page, "%d\n", mddev->degraded);
4364 }
4365 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4366 
4367 static ssize_t
4368 sync_force_parallel_show(struct mddev *mddev, char *page)
4369 {
4370         return sprintf(page, "%d\n", mddev->parallel_resync);
4371 }
4372 
4373 static ssize_t
4374 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4375 {
4376         long n;
4377 
4378         if (kstrtol(buf, 10, &n))
4379                 return -EINVAL;
4380 
4381         if (n != 0 && n != 1)
4382                 return -EINVAL;
4383 
4384         mddev->parallel_resync = n;
4385 
4386         if (mddev->sync_thread)
4387                 wake_up(&resync_wait);
4388 
4389         return len;
4390 }
4391 
4392 /* force parallel resync, even with shared block devices */
4393 static struct md_sysfs_entry md_sync_force_parallel =
4394 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4395        sync_force_parallel_show, sync_force_parallel_store);
4396 
4397 static ssize_t
4398 sync_speed_show(struct mddev *mddev, char *page)
4399 {
4400         unsigned long resync, dt, db;
4401         if (mddev->curr_resync == 0)
4402                 return sprintf(page, "none\n");
4403         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4404         dt = (jiffies - mddev->resync_mark) / HZ;
4405         if (!dt) dt++;
4406         db = resync - mddev->resync_mark_cnt;
4407         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4408 }
4409 
4410 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4411 
4412 static ssize_t
4413 sync_completed_show(struct mddev *mddev, char *page)
4414 {
4415         unsigned long long max_sectors, resync;
4416 
4417         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4418                 return sprintf(page, "none\n");
4419 
4420         if (mddev->curr_resync == 1 ||
4421             mddev->curr_resync == 2)
4422                 return sprintf(page, "delayed\n");
4423 
4424         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4425             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4426                 max_sectors = mddev->resync_max_sectors;
4427         else
4428                 max_sectors = mddev->dev_sectors;
4429 
4430         resync = mddev->curr_resync_completed;
4431         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4432 }
4433 
4434 static struct md_sysfs_entry md_sync_completed =
4435         __ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
4436 
4437 static ssize_t
4438 min_sync_show(struct mddev *mddev, char *page)
4439 {
4440         return sprintf(page, "%llu\n",
4441                        (unsigned long long)mddev->resync_min);
4442 }
4443 static ssize_t
4444 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4445 {
4446         unsigned long long min;
4447         int err;
4448 
4449         if (kstrtoull(buf, 10, &min))
4450                 return -EINVAL;
4451 
4452         spin_lock(&mddev->lock);
4453         err = -EINVAL;
4454         if (min > mddev->resync_max)
4455                 goto out_unlock;
4456 
4457         err = -EBUSY;
4458         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4459                 goto out_unlock;
4460 
4461         /* Round down to multiple of 4K for safety */
4462         mddev->resync_min = round_down(min, 8);
4463         err = 0;
4464 
4465 out_unlock:
4466         spin_unlock(&mddev->lock);
4467         return err ?: len;
4468 }
4469 
4470 static struct md_sysfs_entry md_min_sync =
4471 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4472 
4473 static ssize_t
4474 max_sync_show(struct mddev *mddev, char *page)
4475 {
4476         if (mddev->resync_max == MaxSector)
4477                 return sprintf(page, "max\n");
4478         else
4479                 return sprintf(page, "%llu\n",
4480                                (unsigned long long)mddev->resync_max);
4481 }
4482 static ssize_t
4483 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4484 {
4485         int err;
4486         spin_lock(&mddev->lock);
4487         if (strncmp(buf, "max", 3) == 0)
4488                 mddev->resync_max = MaxSector;
4489         else {
4490                 unsigned long long max;
4491                 int chunk;
4492 
4493                 err = -EINVAL;
4494                 if (kstrtoull(buf, 10, &max))
4495                         goto out_unlock;
4496                 if (max < mddev->resync_min)
4497                         goto out_unlock;
4498 
4499                 err = -EBUSY;
4500                 if (max < mddev->resync_max &&
4501                     mddev->ro == 0 &&
4502                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4503                         goto out_unlock;
4504 
4505                 /* Must be a multiple of chunk_size */
4506                 chunk = mddev->chunk_sectors;
4507                 if (chunk) {
4508                         sector_t temp = max;
4509 
4510                         err = -EINVAL;
4511                         if (sector_div(temp, chunk))
4512                                 goto out_unlock;
4513                 }
4514                 mddev->resync_max = max;
4515         }
4516         wake_up(&mddev->recovery_wait);
4517         err = 0;
4518 out_unlock:
4519         spin_unlock(&mddev->lock);
4520         return err ?: len;
4521 }
4522 
4523 static struct md_sysfs_entry md_max_sync =
4524 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4525 
4526 static ssize_t
4527 suspend_lo_show(struct mddev *mddev, char *page)
4528 {
4529         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4530 }
4531 
4532 static ssize_t
4533 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4534 {
4535         unsigned long long old, new;
4536         int err;
4537 
4538         err = kstrtoull(buf, 10, &new);
4539         if (err < 0)
4540                 return err;
4541         if (new != (sector_t)new)
4542                 return -EINVAL;
4543 
4544         err = mddev_lock(mddev);
4545         if (err)
4546                 return err;
4547         err = -EINVAL;
4548         if (mddev->pers == NULL ||
4549             mddev->pers->quiesce == NULL)
4550                 goto unlock;
4551         old = mddev->suspend_lo;
4552         mddev->suspend_lo = new;
4553         if (new >= old)
4554                 /* Shrinking suspended region */
4555                 mddev->pers->quiesce(mddev, 2);
4556         else {
4557                 /* Expanding suspended region - need to wait */
4558                 mddev->pers->quiesce(mddev, 1);
4559                 mddev->pers->quiesce(mddev, 0);
4560         }
4561         err = 0;
4562 unlock:
4563         mddev_unlock(mddev);
4564         return err ?: len;
4565 }
4566 static struct md_sysfs_entry md_suspend_lo =
4567 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4568 
4569 static ssize_t
4570 suspend_hi_show(struct mddev *mddev, char *page)
4571 {
4572         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4573 }
4574 
4575 static ssize_t
4576 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4577 {
4578         unsigned long long old, new;
4579         int err;
4580 
4581         err = kstrtoull(buf, 10, &new);
4582         if (err < 0)
4583                 return err;
4584         if (new != (sector_t)new)
4585                 return -EINVAL;
4586 
4587         err = mddev_lock(mddev);
4588         if (err)
4589                 return err;
4590         err = -EINVAL;
4591         if (mddev->pers == NULL ||
4592             mddev->pers->quiesce == NULL)
4593                 goto unlock;
4594         old = mddev->suspend_hi;
4595         mddev->suspend_hi = new;
4596         if (new <= old)
4597                 /* Shrinking suspended region */
4598                 mddev->pers->quiesce(mddev, 2);
4599         else {
4600                 /* Expanding suspended region - need to wait */
4601                 mddev->pers->quiesce(mddev, 1);
4602                 mddev->pers->quiesce(mddev, 0);
4603         }
4604         err = 0;
4605 unlock:
4606         mddev_unlock(mddev);
4607         return err ?: len;
4608 }
4609 static struct md_sysfs_entry md_suspend_hi =
4610 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4611 
4612 static ssize_t
4613 reshape_position_show(struct mddev *mddev, char *page)
4614 {
4615         if (mddev->reshape_position != MaxSector)
4616                 return sprintf(page, "%llu\n",
4617                                (unsigned long long)mddev->reshape_position);
4618         strcpy(page, "none\n");
4619         return 5;
4620 }
4621 
4622 static ssize_t
4623 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4624 {
4625         struct md_rdev *rdev;
4626         unsigned long long new;
4627         int err;
4628 
4629         err = kstrtoull(buf, 10, &new);
4630         if (err < 0)
4631                 return err;
4632         if (new != (sector_t)new)
4633                 return -EINVAL;
4634         err = mddev_lock(mddev);
4635         if (err)
4636                 return err;
4637         err = -EBUSY;
4638         if (mddev->pers)
4639                 goto unlock;
4640         mddev->reshape_position = new;
4641         mddev->delta_disks = 0;
4642         mddev->reshape_backwards = 0;
4643         mddev->new_level = mddev->level;
4644         mddev->new_layout = mddev->layout;
4645         mddev->new_chunk_sectors = mddev->chunk_sectors;
4646         rdev_for_each(rdev, mddev)
4647                 rdev->new_data_offset = rdev->data_offset;
4648         err = 0;
4649 unlock:
4650         mddev_unlock(mddev);
4651         return err ?: len;
4652 }
4653 
4654 static struct md_sysfs_entry md_reshape_position =
4655 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4656        reshape_position_store);
4657 
4658 static ssize_t
4659 reshape_direction_show(struct mddev *mddev, char *page)
4660 {
4661         return sprintf(page, "%s\n",
4662                        mddev->reshape_backwards ? "backwards" : "forwards");
4663 }
4664 
4665 static ssize_t
4666 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4667 {
4668         int backwards = 0;
4669         int err;
4670 
4671         if (cmd_match(buf, "forwards"))
4672                 backwards = 0;
4673         else if (cmd_match(buf, "backwards"))
4674                 backwards = 1;
4675         else
4676                 return -EINVAL;
4677         if (mddev->reshape_backwards == backwards)
4678                 return len;
4679 
4680         err = mddev_lock(mddev);
4681         if (err)
4682                 return err;
4683         /* check if we are allowed to change */
4684         if (mddev->delta_disks)
4685                 err = -EBUSY;
4686         else if (mddev->persistent &&
4687             mddev->major_version == 0)
4688                 err =  -EINVAL;
4689         else
4690                 mddev->reshape_backwards = backwards;
4691         mddev_unlock(mddev);
4692         return err ?: len;
4693 }
4694 
4695 static struct md_sysfs_entry md_reshape_direction =
4696 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4697        reshape_direction_store);
4698 
4699 static ssize_t
4700 array_size_show(struct mddev *mddev, char *page)
4701 {
4702         if (mddev->external_size)
4703                 return sprintf(page, "%llu\n",
4704                                (unsigned long long)mddev->array_sectors/2);
4705         else
4706                 return sprintf(page, "default\n");
4707 }
4708 
4709 static ssize_t
4710 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4711 {
4712         sector_t sectors;
4713         int err;
4714 
4715         err = mddev_lock(mddev);
4716         if (err)
4717                 return err;
4718 
4719         if (strncmp(buf, "default", 7) == 0) {
4720                 if (mddev->pers)
4721                         sectors = mddev->pers->size(mddev, 0, 0);
4722                 else
4723                         sectors = mddev->array_sectors;
4724 
4725                 mddev->external_size = 0;
4726         } else {
4727                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
4728                         err = -EINVAL;
4729                 else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4730                         err = -E2BIG;
4731                 else
4732                         mddev->external_size = 1;
4733         }
4734 
4735         if (!err) {
4736                 mddev->array_sectors = sectors;
4737                 if (mddev->pers) {
4738                         set_capacity(mddev->gendisk, mddev->array_sectors);
4739                         revalidate_disk(mddev->gendisk);
4740                 }
4741         }
4742         mddev_unlock(mddev);
4743         return err ?: len;
4744 }
4745 
4746 static struct md_sysfs_entry md_array_size =
4747 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4748        array_size_store);
4749 
4750 static struct attribute *md_default_attrs[] = {
4751         &md_level.attr,
4752         &md_layout.attr,
4753         &md_raid_disks.attr,
4754         &md_chunk_size.attr,
4755         &md_size.attr,
4756         &md_resync_start.attr,
4757         &md_metadata.attr,
4758         &md_new_device.attr,
4759         &md_safe_delay.attr,
4760         &md_array_state.attr,
4761         &md_reshape_position.attr,
4762         &md_reshape_direction.attr,
4763         &md_array_size.attr,
4764         &max_corr_read_errors.attr,
4765         NULL,
4766 };
4767 
4768 static struct attribute *md_redundancy_attrs[] = {
4769         &md_scan_mode.attr,
4770         &md_last_scan_mode.attr,
4771         &md_mismatches.attr,
4772         &md_sync_min.attr,
4773         &md_sync_max.attr,
4774         &md_sync_speed.attr,
4775         &md_sync_force_parallel.attr,
4776         &md_sync_completed.attr,
4777         &md_min_sync.attr,
4778         &md_max_sync.attr,
4779         &md_suspend_lo.attr,
4780         &md_suspend_hi.attr,
4781         &md_bitmap.attr,
4782         &md_degraded.attr,
4783         NULL,
4784 };
4785 static struct attribute_group md_redundancy_group = {
4786         .name = NULL,
4787         .attrs = md_redundancy_attrs,
4788 };
4789 
4790 static ssize_t
4791 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4792 {
4793         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4794         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4795         ssize_t rv;
4796 
4797         if (!entry->show)
4798                 return -EIO;
4799         spin_lock(&all_mddevs_lock);
4800         if (list_empty(&mddev->all_mddevs)) {
4801                 spin_unlock(&all_mddevs_lock);
4802                 return -EBUSY;
4803         }
4804         mddev_get(mddev);
4805         spin_unlock(&all_mddevs_lock);
4806 
4807         rv = entry->show(mddev, page);
4808         mddev_put(mddev);
4809         return rv;
4810 }
4811 
4812 static ssize_t
4813 md_attr_store(struct kobject *kobj, struct attribute *attr,
4814               const char *page, size_t length)
4815 {
4816         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4817         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4818         ssize_t rv;
4819 
4820         if (!entry->store)
4821                 return -EIO;
4822         if (!capable(CAP_SYS_ADMIN))
4823                 return -EACCES;
4824         spin_lock(&all_mddevs_lock);
4825         if (list_empty(&mddev->all_mddevs)) {
4826                 spin_unlock(&all_mddevs_lock);
4827                 return -EBUSY;
4828         }
4829         mddev_get(mddev);
4830         spin_unlock(&all_mddevs_lock);
4831         rv = entry->store(mddev, page, length);
4832         mddev_put(mddev);
4833         return rv;
4834 }
4835 
4836 static void md_free(struct kobject *ko)
4837 {
4838         struct mddev *mddev = container_of(ko, struct mddev, kobj);
4839 
4840         if (mddev->sysfs_state)
4841                 sysfs_put(mddev->sysfs_state);
4842 
4843         if (mddev->queue)
4844                 blk_cleanup_queue(mddev->queue);
4845         if (mddev->gendisk) {
4846                 del_gendisk(mddev->gendisk);
4847                 put_disk(mddev->gendisk);
4848         }
4849 
4850         kfree(mddev);
4851 }
4852 
4853 static const struct sysfs_ops md_sysfs_ops = {
4854         .show   = md_attr_show,
4855         .store  = md_attr_store,
4856 };
4857 static struct kobj_type md_ktype = {
4858         .release        = md_free,
4859         .sysfs_ops      = &md_sysfs_ops,
4860         .default_attrs  = md_default_attrs,
4861 };
4862 
4863 int mdp_major = 0;
4864 
4865 static void mddev_delayed_delete(struct work_struct *ws)
4866 {
4867         struct mddev *mddev = container_of(ws, struct mddev, del_work);
4868 
4869         sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4870         kobject_del(&mddev->kobj);
4871         kobject_put(&mddev->kobj);
4872 }
4873 
4874 static int md_alloc(dev_t dev, char *name)
4875 {
4876         static DEFINE_MUTEX(disks_mutex);
4877         struct mddev *mddev = mddev_find(dev);
4878         struct gendisk *disk;
4879         int partitioned;
4880         int shift;
4881         int unit;
4882         int error;
4883 
4884         if (!mddev)
4885                 return -ENODEV;
4886 
4887         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4888         shift = partitioned ? MdpMinorShift : 0;
4889         unit = MINOR(mddev->unit) >> shift;
4890 
4891         /* wait for any previous instance of this device to be
4892          * completely removed (mddev_delayed_delete).
4893          */
4894         flush_workqueue(md_misc_wq);
4895 
4896         mutex_lock(&disks_mutex);
4897         error = -EEXIST;
4898         if (mddev->gendisk)
4899                 goto abort;
4900 
4901         if (name) {
4902                 /* Need to ensure that 'name' is not a duplicate.
4903                  */
4904                 struct mddev *mddev2;
4905                 spin_lock(&all_mddevs_lock);
4906 
4907                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4908                         if (mddev2->gendisk &&
4909                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
4910                                 spin_unlock(&all_mddevs_lock);
4911                                 goto abort;
4912                         }
4913                 spin_unlock(&all_mddevs_lock);
4914         }
4915 
4916         error = -ENOMEM;
4917         mddev->queue = blk_alloc_queue(GFP_KERNEL);
4918         if (!mddev->queue)
4919                 goto abort;
4920         mddev->queue->queuedata = mddev;
4921 
4922         blk_queue_make_request(mddev->queue, md_make_request);
4923         blk_set_stacking_limits(&mddev->queue->limits);
4924 
4925         disk = alloc_disk(1 << shift);
4926         if (!disk) {
4927                 blk_cleanup_queue(mddev->queue);
4928                 mddev->queue = NULL;
4929                 goto abort;
4930         }
4931         disk->major = MAJOR(mddev->unit);
4932         disk->first_minor = unit << shift;
4933         if (name)
4934                 strcpy(disk->disk_name, name);
4935         else if (partitioned)
4936                 sprintf(disk->disk_name, "md_d%d", unit);
4937         else
4938                 sprintf(disk->disk_name, "md%d", unit);
4939         disk->fops = &md_fops;
4940         disk->private_data = mddev;
4941         disk->queue = mddev->queue;
4942         blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4943         /* Allow extended partitions.  This makes the
4944          * 'mdp' device redundant, but we can't really
4945          * remove it now.
4946          */
4947         disk->flags |= GENHD_FL_EXT_DEVT;
4948         mddev->gendisk = disk;
4949         /* As soon as we call add_disk(), another thread could get
4950          * through to md_open, so make sure it doesn't get too far
4951          */
4952         mutex_lock(&mddev->open_mutex);
4953         add_disk(disk);
4954 
4955         error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4956                                      &disk_to_dev(disk)->kobj, "%s", "md");
4957         if (error) {
4958                 /* This isn't possible, but as kobject_init_and_add is marked
4959                  * __must_check, we must do something with the result
4960                  */
4961                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4962                        disk->disk_name);
4963                 error = 0;
4964         }
4965         if (mddev->kobj.sd &&
4966             sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4967                 printk(KERN_DEBUG "pointless warning\n");
4968         mutex_unlock(&mddev->open_mutex);
4969  abort:
4970         mutex_unlock(&disks_mutex);
4971         if (!error && mddev->kobj.sd) {
4972                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
4973                 mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4974         }
4975         mddev_put(mddev);
4976         return error;
4977 }
4978 
4979 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4980 {
4981         md_alloc(dev, NULL);
4982         return NULL;
4983 }
4984 
4985 static int add_named_array(const char *val, struct kernel_param *kp)
4986 {
4987         /* val must be "md_*" where * is not all digits.
4988          * We allocate an array with a large free minor number, and
4989          * set the name to val.  val must not already be an active name.
4990          */
4991         int len = strlen(val);
4992         char buf[DISK_NAME_LEN];
4993 
4994         while (len && val[len-1] == '\n')
4995                 len--;
4996         if (len >= DISK_NAME_LEN)
4997                 return -E2BIG;
4998         strlcpy(buf, val, len+1);
4999         if (strncmp(buf, "md_", 3) != 0)
5000                 return -EINVAL;
5001         return md_alloc(0, buf);
5002 }
5003 
5004 static void md_safemode_timeout(unsigned long data)
5005 {
5006         struct mddev *mddev = (struct mddev *) data;
5007 
5008         if (!atomic_read(&mddev->writes_pending)) {
5009                 mddev->safemode = 1;
5010                 if (mddev->external)
5011                         sysfs_notify_dirent_safe(mddev->sysfs_state);
5012         }
5013         md_wakeup_thread(mddev->thread);
5014 }
5015 
5016 static int start_dirty_degraded;
5017 
5018 int md_run(struct mddev *mddev)
5019 {
5020         int err;
5021         struct md_rdev *rdev;
5022         struct md_personality *pers;
5023 
5024         if (list_empty(&mddev->disks))
5025                 /* cannot run an array with no devices.. */
5026                 return -EINVAL;
5027 
5028         if (mddev->pers)
5029                 return -EBUSY;
5030         /* Cannot run until previous stop completes properly */
5031         if (mddev->sysfs_active)
5032                 return -EBUSY;
5033 
5034         /*
5035          * Analyze all RAID superblock(s)
5036          */
5037         if (!mddev->raid_disks) {
5038                 if (!mddev->persistent)
5039                         return -EINVAL;
5040                 analyze_sbs(mddev);
5041         }
5042 
5043         if (mddev->level != LEVEL_NONE)
5044                 request_module("md-level-%d", mddev->level);
5045         else if (mddev->clevel[0])
5046                 request_module("md-%s", mddev->clevel);
5047 
5048         /*
5049          * Drop all container device buffers, from now on
5050          * the only valid external interface is through the md
5051          * device.
5052          */
5053         rdev_for_each(rdev, mddev) {
5054                 if (test_bit(Faulty, &rdev->flags))
5055                         continue;
5056                 sync_blockdev(rdev->bdev);
5057                 invalidate_bdev(rdev->bdev);
5058 
5059                 /* perform some consistency tests on the device.
5060                  * We don't want the data to overlap the metadata,
5061                  * Internal Bitmap issues have been handled elsewhere.
5062                  */
5063                 if (rdev->meta_bdev) {
5064                         /* Nothing to check */;
5065                 } else if (rdev->data_offset < rdev->sb_start) {
5066                         if (mddev->dev_sectors &&
5067                             rdev->data_offset + mddev->dev_sectors
5068                             > rdev->sb_start) {
5069                                 printk("md: %s: data overlaps metadata\n",
5070                                        mdname(mddev));
5071                                 return -EINVAL;
5072                         }
5073                 } else {
5074                         if (rdev->sb_start + rdev->sb_size/512
5075                             > rdev->data_offset) {
5076                                 printk("md: %s: metadata overlaps data\n",
5077                                        mdname(mddev));
5078                                 return -EINVAL;
5079                         }
5080                 }
5081                 sysfs_notify_dirent_safe(rdev->sysfs_state);
5082         }
5083 
5084         if (mddev->bio_set == NULL)
5085                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
5086 
5087         spin_lock(&pers_lock);
5088         pers = find_pers(mddev->level, mddev->clevel);
5089         if (!pers || !try_module_get(pers->owner)) {
5090                 spin_unlock(&pers_lock);
5091                 if (mddev->level != LEVEL_NONE)
5092                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5093                                mddev->level);
5094                 else
5095                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5096                                mddev->clevel);
5097                 return -EINVAL;
5098         }
5099         spin_unlock(&pers_lock);
5100         if (mddev->level != pers->level) {
5101                 mddev->level = pers->level;
5102                 mddev->new_level = pers->level;
5103         }
5104         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5105 
5106         if (mddev->reshape_position != MaxSector &&
5107             pers->start_reshape == NULL) {
5108                 /* This personality cannot handle reshaping... */
5109                 module_put(pers->owner);
5110                 return -EINVAL;
5111         }
5112 
5113         if (pers->sync_request) {
5114                 /* Warn if this is a potentially silly
5115                  * configuration.
5116                  */
5117                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5118                 struct md_rdev *rdev2;
5119                 int warned = 0;
5120 
5121                 rdev_for_each(rdev, mddev)
5122                         rdev_for_each(rdev2, mddev) {
5123                                 if (rdev < rdev2 &&
5124                                     rdev->bdev->bd_contains ==
5125                                     rdev2->bdev->bd_contains) {
5126                                         printk(KERN_WARNING
5127                                                "%s: WARNING: %s appears to be"
5128                                                " on the same physical disk as"
5129                                                " %s.\n",
5130                                                mdname(mddev),
5131                                                bdevname(rdev->bdev,b),
5132                                                bdevname(rdev2->bdev,b2));
5133                                         warned = 1;
5134                                 }
5135                         }
5136 
5137                 if (warned)
5138                         printk(KERN_WARNING
5139                                "True protection against single-disk"
5140                                " failure might be compromised.\n");
5141         }
5142 
5143         mddev->recovery = 0;
5144         /* may be over-ridden by personality */
5145         mddev->resync_max_sectors = mddev->dev_sectors;
5146 
5147         mddev->ok_start_degraded = start_dirty_degraded;
5148 
5149         if (start_readonly && mddev->ro == 0)
5150                 mddev->ro = 2; /* read-only, but switch on first write */
5151 
5152         err = pers->run(mddev);
5153         if (err)
5154                 printk(KERN_ERR "md: pers->run() failed ...\n");
5155         else if (pers->size(mddev, 0, 0) < mddev->array_sectors) {
5156                 WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5157                           " but 'external_size' not in effect?\n", __func__);
5158                 printk(KERN_ERR
5159                        "md: invalid array_size %llu > default size %llu\n",
5160                        (unsigned long long)mddev->array_sectors / 2,
5161                        (unsigned long long)pers->size(mddev, 0, 0) / 2);
5162                 err = -EINVAL;
5163         }
5164         if (err == 0 && pers->sync_request &&
5165             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5166                 struct bitmap *bitmap;
5167 
5168                 bitmap = bitmap_create(mddev, -1);
5169                 if (IS_ERR(bitmap)) {
5170                         err = PTR_ERR(bitmap);
5171                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5172                                mdname(mddev), err);
5173                 } else
5174                         mddev->bitmap = bitmap;
5175 
5176         }
5177         if (err) {
5178                 mddev_detach(mddev);
5179                 if (mddev->private)
5180                         pers->free(mddev, mddev->private);
5181                 mddev->private = NULL;
5182                 module_put(pers->owner);
5183                 bitmap_destroy(mddev);
5184                 return err;
5185         }
5186         if (mddev->queue) {
5187                 mddev->queue->backing_dev_info.congested_data = mddev;
5188                 mddev->queue->backing_dev_info.congested_fn = md_congested;
5189                 blk_queue_merge_bvec(mddev->queue, md_mergeable_bvec);
5190         }
5191         if (pers->sync_request) {
5192                 if (mddev->kobj.sd &&
5193                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5194                         printk(KERN_WARNING
5195                                "md: cannot register extra attributes for %s\n",
5196                                mdname(mddev));
5197                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5198         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
5199                 mddev->ro = 0;
5200 
5201         atomic_set(&mddev->writes_pending,0);
5202         atomic_set(&mddev->max_corr_read_errors,
5203                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5204         mddev->safemode = 0;
5205         mddev->safemode_timer.function = md_safemode_timeout;
5206         mddev->safemode_timer.data = (unsigned long) mddev;
5207         mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5208         mddev->in_sync = 1;
5209         smp_wmb();
5210         spin_lock(&mddev->lock);
5211         mddev->pers = pers;
5212         mddev->ready = 1;
5213         spin_unlock(&mddev->lock);
5214         rdev_for_each(rdev, mddev)
5215                 if (rdev->raid_disk >= 0)
5216                         if (sysfs_link_rdev(mddev, rdev))
5217                                 /* failure here is OK */;
5218 
5219         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5220 
5221         if (mddev->flags & MD_UPDATE_SB_FLAGS)
5222                 md_update_sb(mddev, 0);
5223 
5224         md_new_event(mddev);
5225         sysfs_notify_dirent_safe(mddev->sysfs_state);
5226         sysfs_notify_dirent_safe(mddev->sysfs_action);
5227         sysfs_notify(&mddev->kobj, NULL, "degraded");
5228         return 0;
5229 }
5230 EXPORT_SYMBOL_GPL(md_run);
5231 
5232 static int do_md_run(struct mddev *mddev)
5233 {
5234         int err;
5235 
5236         err = md_run(mddev);
5237         if (err)
5238                 goto out;
5239         err = bitmap_load(mddev);
5240         if (err) {
5241                 bitmap_destroy(mddev);
5242                 goto out;
5243         }
5244 
5245         md_wakeup_thread(mddev->thread);
5246         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5247 
5248         set_capacity(mddev->gendisk, mddev->array_sectors);
5249         revalidate_disk(mddev->gendisk);
5250         mddev->changed = 1;
5251         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5252 out:
5253         return err;
5254 }
5255 
5256 static int restart_array(struct mddev *mddev)
5257 {
5258         struct gendisk *disk = mddev->gendisk;
5259 
5260         /* Complain if it has no devices */
5261         if (list_empty(&mddev->disks))
5262                 return -ENXIO;
5263         if (!mddev->pers)
5264                 return -EINVAL;
5265         if (!mddev->ro)
5266                 return -EBUSY;
5267         mddev->safemode = 0;
5268         mddev->ro = 0;
5269         set_disk_ro(disk, 0);
5270         printk(KERN_INFO "md: %s switched to read-write mode.\n",
5271                 mdname(mddev));
5272         /* Kick recovery or resync if necessary */
5273         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5274         md_wakeup_thread(mddev->thread);
5275         md_wakeup_thread(mddev->sync_thread);
5276         sysfs_notify_dirent_safe(mddev->sysfs_state);
5277         return 0;
5278 }
5279 
5280 static void md_clean(struct mddev *mddev)
5281 {
5282         mddev->array_sectors = 0;
5283         mddev->external_size = 0;
5284         mddev->dev_sectors = 0;
5285         mddev->raid_disks = 0;
5286         mddev->recovery_cp = 0;
5287         mddev->resync_min = 0;
5288         mddev->resync_max = MaxSector;
5289         mddev->reshape_position = MaxSector;
5290         mddev->external = 0;
5291         mddev->persistent = 0;
5292         mddev->level = LEVEL_NONE;
5293         mddev->clevel[0] = 0;
5294         mddev->flags = 0;
5295         mddev->ro = 0;
5296         mddev->metadata_type[0] = 0;
5297         mddev->chunk_sectors = 0;
5298         mddev->ctime = mddev->utime = 0;
5299         mddev->layout = 0;
5300         mddev->max_disks = 0;
5301         mddev->events = 0;
5302         mddev->can_decrease_events = 0;
5303         mddev->delta_disks = 0;
5304         mddev->reshape_backwards = 0;
5305         mddev->new_level = LEVEL_NONE;
5306         mddev->new_layout = 0;
5307         mddev->new_chunk_sectors = 0;
5308         mddev->curr_resync = 0;
5309         atomic64_set(&mddev->resync_mismatches, 0);
5310         mddev->suspend_lo = mddev->suspend_hi = 0;
5311         mddev->sync_speed_min = mddev->sync_speed_max = 0;
5312         mddev->recovery = 0;
5313         mddev->in_sync = 0;
5314         mddev->changed = 0;
5315         mddev->degraded = 0;
5316         mddev->safemode = 0;
5317         mddev->private = NULL;
5318         mddev->merge_check_needed = 0;
5319         mddev->bitmap_info.offset = 0;
5320         mddev->bitmap_info.default_offset = 0;
5321         mddev->bitmap_info.default_space = 0;
5322         mddev->bitmap_info.chunksize = 0;
5323         mddev->bitmap_info.daemon_sleep = 0;
5324         mddev->bitmap_info.max_write_behind = 0;
5325 }
5326 
5327 static void __md_stop_writes(struct mddev *mddev)
5328 {
5329         if (mddev_is_clustered(mddev))
5330                 md_cluster_ops->metadata_update_start(mddev);
5331         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5332         flush_workqueue(md_misc_wq);
5333         if (mddev->sync_thread) {
5334                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5335                 md_reap_sync_thread(mddev);
5336         }
5337 
5338         del_timer_sync(&mddev->safemode_timer);
5339 
5340         bitmap_flush(mddev);
5341         md_super_wait(mddev);
5342 
5343         if (mddev->ro == 0 &&
5344             (!mddev->in_sync || (mddev->flags & MD_UPDATE_SB_FLAGS))) {
5345                 /* mark array as shutdown cleanly */
5346                 mddev->in_sync = 1;
5347                 md_update_sb(mddev, 1);
5348         }
5349         if (mddev_is_clustered(mddev))
5350                 md_cluster_ops->metadata_update_finish(mddev);
5351 }
5352 
5353 void md_stop_writes(struct mddev *mddev)
5354 {
5355         mddev_lock_nointr(mddev);
5356         __md_stop_writes(mddev);
5357         mddev_unlock(mddev);
5358 }
5359 EXPORT_SYMBOL_GPL(md_stop_writes);
5360 
5361 static void mddev_detach(struct mddev *mddev)
5362 {
5363         struct bitmap *bitmap = mddev->bitmap;
5364         /* wait for behind writes to complete */
5365         if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
5366                 printk(KERN_INFO "md:%s: behind writes in progress - waiting to stop.\n",
5367                        mdname(mddev));
5368                 /* need to kick something here to make sure I/O goes? */
5369                 wait_event(bitmap->behind_wait,
5370                            atomic_read(&bitmap->behind_writes) == 0);
5371         }
5372         if (mddev->pers && mddev->pers->quiesce) {
5373                 mddev->pers->quiesce(mddev, 1);
5374                 mddev->pers->quiesce(mddev, 0);
5375         }
5376         md_unregister_thread(&mddev->thread);
5377         if (mddev->queue)
5378                 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
5379 }
5380 
5381 static void __md_stop(struct mddev *mddev)
5382 {
5383         struct md_personality *pers = mddev->pers;
5384         mddev_detach(mddev);
5385         /* Ensure ->event_work is done */
5386         flush_workqueue(md_misc_wq);
5387         spin_lock(&mddev->lock);
5388         mddev->ready = 0;
5389         mddev->pers = NULL;
5390         spin_unlock(&mddev->lock);
5391         pers->free(mddev, mddev->private);
5392         mddev->private = NULL;
5393         if (pers->sync_request && mddev->to_remove == NULL)
5394                 mddev->to_remove = &md_redundancy_group;
5395         module_put(pers->owner);
5396         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5397 }
5398 
5399 void md_stop(struct mddev *mddev)
5400 {
5401         /* stop the array and free an attached data structures.
5402          * This is called from dm-raid
5403          */
5404         __md_stop(mddev);
5405         bitmap_destroy(mddev);
5406         if (mddev->bio_set)
5407                 bioset_free(mddev->bio_set);
5408 }
5409 
5410 EXPORT_SYMBOL_GPL(md_stop);
5411 
5412 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5413 {
5414         int err = 0;
5415         int did_freeze = 0;
5416 
5417         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5418                 did_freeze = 1;
5419                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5420                 md_wakeup_thread(mddev->thread);
5421         }
5422         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5423                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5424         if (mddev->sync_thread)
5425                 /* Thread might be blocked waiting for metadata update
5426                  * which will now never happen */
5427                 wake_up_process(mddev->sync_thread->tsk);
5428 
5429         mddev_unlock(mddev);
5430         wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
5431                                           &mddev->recovery));
5432         mddev_lock_nointr(mddev);
5433 
5434         mutex_lock(&mddev->open_mutex);
5435         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5436             mddev->sync_thread ||
5437             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5438             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5439                 printk("md: %s still in use.\n",mdname(mddev));
5440                 if (did_freeze) {
5441                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5442                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5443                         md_wakeup_thread(mddev->thread);
5444                 }
5445                 err = -EBUSY;
5446                 goto out;
5447         }
5448         if (mddev->pers) {
5449                 __md_stop_writes(mddev);
5450 
5451                 err  = -ENXIO;
5452                 if (mddev->ro==1)
5453                         goto out;
5454                 mddev->ro = 1;
5455                 set_disk_ro(mddev->gendisk, 1);
5456                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5457                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5458                 md_wakeup_thread(mddev->thread);
5459                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5460                 err = 0;
5461         }
5462 out:
5463         mutex_unlock(&mddev->open_mutex);
5464         return err;
5465 }
5466 
5467 /* mode:
5468  *   0 - completely stop and dis-assemble array
5469  *   2 - stop but do not disassemble array
5470  */
5471 static int do_md_stop(struct mddev *mddev, int mode,
5472                       struct block_device *bdev)
5473 {
5474         struct gendisk *disk = mddev->gendisk;
5475         struct md_rdev *rdev;
5476         int did_freeze = 0;
5477 
5478         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5479                 did_freeze = 1;
5480                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5481                 md_wakeup_thread(mddev->thread);
5482         }
5483         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5484                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5485         if (mddev->sync_thread)
5486                 /* Thread might be blocked waiting for metadata update
5487                  * which will now never happen */
5488                 wake_up_process(mddev->sync_thread->tsk);
5489 
5490         mddev_unlock(mddev);
5491         wait_event(resync_wait, (mddev->sync_thread == NULL &&
5492                                  !test_bit(MD_RECOVERY_RUNNING,
5493                                            &mddev->recovery)));
5494         mddev_lock_nointr(mddev);
5495 
5496         mutex_lock(&mddev->open_mutex);
5497         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5498             mddev->sysfs_active ||
5499             mddev->sync_thread ||
5500             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5501             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5502                 printk("md: %s still in use.\n",mdname(mddev));
5503                 mutex_unlock(&mddev->open_mutex);
5504                 if (did_freeze) {
5505                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5506                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5507                         md_wakeup_thread(mddev->thread);
5508                 }
5509                 return -EBUSY;
5510         }
5511         if (mddev->pers) {
5512                 if (mddev->ro)
5513                         set_disk_ro(disk, 0);
5514 
5515                 __md_stop_writes(mddev);
5516                 __md_stop(mddev);
5517                 mddev->queue->merge_bvec_fn = NULL;
5518                 mddev->queue->backing_dev_info.congested_fn = NULL;
5519 
5520                 /* tell userspace to handle 'inactive' */
5521                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5522 
5523                 rdev_for_each(rdev, mddev)
5524                         if (rdev->raid_disk >= 0)
5525                                 sysfs_unlink_rdev(mddev, rdev);
5526 
5527                 set_capacity(disk, 0);
5528                 mutex_unlock(&mddev->open_mutex);
5529                 mddev->changed = 1;
5530                 revalidate_disk(disk);
5531 
5532                 if (mddev->ro)
5533                         mddev->ro = 0;
5534         } else
5535                 mutex_unlock(&mddev->open_mutex);
5536         /*
5537          * Free resources if final stop
5538          */
5539         if (mode == 0) {
5540                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5541 
5542                 bitmap_destroy(mddev);
5543                 if (mddev->bitmap_info.file) {
5544                         struct file *f = mddev->bitmap_info.file;
5545                         spin_lock(&mddev->lock);
5546                         mddev->bitmap_info.file = NULL;
5547                         spin_unlock(&mddev->lock);
5548                         fput(f);
5549                 }
5550                 mddev->bitmap_info.offset = 0;
5551 
5552                 export_array(mddev);
5553 
5554                 md_clean(mddev);
5555                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5556                 if (mddev->hold_active == UNTIL_STOP)
5557                         mddev->hold_active = 0;
5558         }
5559         blk_integrity_unregister(disk);
5560         md_new_event(mddev);
5561         sysfs_notify_dirent_safe(mddev->sysfs_state);
5562         return 0;
5563 }
5564 
5565 #ifndef MODULE
5566 static void autorun_array(struct mddev *mddev)
5567 {
5568         struct md_rdev *rdev;
5569         int err;
5570 
5571         if (list_empty(&mddev->disks))
5572                 return;
5573 
5574         printk(KERN_INFO "md: running: ");
5575 
5576         rdev_for_each(rdev, mddev) {
5577                 char b[BDEVNAME_SIZE];
5578                 printk("<%s>", bdevname(rdev->bdev,b));
5579         }
5580         printk("\n");
5581 
5582         err = do_md_run(mddev);
5583         if (err) {
5584                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5585                 do_md_stop(mddev, 0, NULL);
5586         }
5587 }
5588 
5589 /*
5590  * lets try to run arrays based on all disks that have arrived
5591  * until now. (those are in pending_raid_disks)
5592  *
5593  * the method: pick the first pending disk, collect all disks with
5594  * the same UUID, remove all from the pending list and put them into
5595  * the 'same_array' list. Then order this list based on superblock
5596  * update time (freshest comes first), kick out 'old' disks and
5597  * compare superblocks. If everything's fine then run it.
5598  *
5599  * If "unit" is allocated, then bump its reference count
5600  */
5601 static void autorun_devices(int part)
5602 {
5603         struct md_rdev *rdev0, *rdev, *tmp;
5604         struct mddev *mddev;
5605         char b[BDEVNAME_SIZE];
5606 
5607         printk(KERN_INFO "md: autorun ...\n");
5608         while (!list_empty(&pending_raid_disks)) {
5609                 int unit;
5610                 dev_t dev;
5611                 LIST_HEAD(candidates);
5612                 rdev0 = list_entry(pending_raid_disks.next,
5613                                          struct md_rdev, same_set);
5614 
5615                 printk(KERN_INFO "md: considering %s ...\n",
5616                         bdevname(rdev0->bdev,b));
5617                 INIT_LIST_HEAD(&candidates);
5618                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5619                         if (super_90_load(rdev, rdev0, 0) >= 0) {
5620                                 printk(KERN_INFO "md:  adding %s ...\n",
5621                                         bdevname(rdev->bdev,b));
5622                                 list_move(&rdev->same_set, &candidates);
5623                         }
5624                 /*
5625                  * now we have a set of devices, with all of them having
5626                  * mostly sane superblocks. It's time to allocate the
5627                  * mddev.
5628                  */
5629                 if (part) {
5630                         dev = MKDEV(mdp_major,
5631                                     rdev0->preferred_minor << MdpMinorShift);
5632                         unit = MINOR(dev) >> MdpMinorShift;
5633                 } else {
5634                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5635                         unit = MINOR(dev);
5636                 }
5637                 if (rdev0->preferred_minor != unit) {
5638                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5639                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5640                         break;
5641                 }
5642 
5643                 md_probe(dev, NULL, NULL);
5644                 mddev = mddev_find(dev);
5645                 if (!mddev || !mddev->gendisk) {
5646                         if (mddev)
5647                                 mddev_put(mddev);
5648                         printk(KERN_ERR
5649                                 "md: cannot allocate memory for md drive.\n");
5650                         break;
5651                 }
5652                 if (mddev_lock(mddev))
5653                         printk(KERN_WARNING "md: %s locked, cannot run\n",
5654                                mdname(mddev));
5655                 else if (mddev->raid_disks || mddev->major_version
5656                          || !list_empty(&mddev->disks)) {
5657                         printk(KERN_WARNING
5658                                 "md: %s already running, cannot run %s\n",
5659                                 mdname(mddev), bdevname(rdev0->bdev,b));
5660                         mddev_unlock(mddev);
5661                 } else {
5662                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
5663                         mddev->persistent = 1;
5664                         rdev_for_each_list(rdev, tmp, &candidates) {
5665                                 list_del_init(&rdev->same_set);
5666                                 if (bind_rdev_to_array(rdev, mddev))
5667                                         export_rdev(rdev);
5668                         }
5669                         autorun_array(mddev);
5670                         mddev_unlock(mddev);
5671                 }
5672                 /* on success, candidates will be empty, on error
5673                  * it won't...
5674                  */
5675                 rdev_for_each_list(rdev, tmp, &candidates) {
5676                         list_del_init(&rdev->same_set);
5677                         export_rdev(rdev);
5678                 }
5679                 mddev_put(mddev);
5680         }
5681         printk(KERN_INFO "md: ... autorun DONE.\n");
5682 }
5683 #endif /* !MODULE */
5684 
5685 static int get_version(void __user *arg)
5686 {
5687         mdu_version_t ver;
5688 
5689         ver.major = MD_MAJOR_VERSION;
5690         ver.minor = MD_MINOR_VERSION;
5691         ver.patchlevel = MD_PATCHLEVEL_VERSION;
5692 
5693         if (copy_to_user(arg, &ver, sizeof(ver)))
5694                 return -EFAULT;
5695 
5696         return 0;
5697 }
5698 
5699 static int get_array_info(struct mddev *mddev, void __user *arg)
5700 {
5701         mdu_array_info_t info;
5702         int nr,working,insync,failed,spare;
5703         struct md_rdev *rdev;
5704 
5705         nr = working = insync = failed = spare = 0;
5706         rcu_read_lock();
5707         rdev_for_each_rcu(rdev, mddev) {
5708                 nr++;
5709                 if (test_bit(Faulty, &rdev->flags))
5710                         failed++;
5711                 else {
5712                         working++;
5713                         if (test_bit(In_sync, &rdev->flags))
5714                                 insync++;
5715                         else
5716                                 spare++;
5717                 }
5718         }
5719         rcu_read_unlock();
5720 
5721         info.major_version = mddev->major_version;
5722         info.minor_version = mddev->minor_version;
5723         info.patch_version = MD_PATCHLEVEL_VERSION;
5724         info.ctime         = mddev->ctime;
5725         info.level         = mddev->level;
5726         info.size          = mddev->dev_sectors / 2;
5727         if (info.size != mddev->dev_sectors / 2) /* overflow */
5728                 info.size = -1;
5729         info.nr_disks      = nr;
5730         info.raid_disks    = mddev->raid_disks;
5731         info.md_minor      = mddev->md_minor;
5732         info.not_persistent= !mddev->persistent;
5733 
5734         info.utime         = mddev->utime;
5735         info.state         = 0;
5736         if (mddev->in_sync)
5737                 info.state = (1<<MD_SB_CLEAN);
5738         if (mddev->bitmap && mddev->bitmap_info.offset)
5739                 info.state |= (1<<MD_SB_BITMAP_PRESENT);
5740         if (mddev_is_clustered(mddev))
5741                 info.state |= (1<<MD_SB_CLUSTERED);
5742         info.active_disks  = insync;
5743         info.working_disks = working;
5744         info.failed_disks  = failed;
5745         info.spare_disks   = spare;
5746 
5747         info.layout        = mddev->layout;
5748         info.chunk_size    = mddev->chunk_sectors << 9;
5749 
5750         if (copy_to_user(arg, &info, sizeof(info)))
5751                 return -EFAULT;
5752 
5753         return 0;
5754 }
5755 
5756 static int get_bitmap_file(struct mddev *mddev, void __user * arg)
5757 {
5758         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5759         char *ptr;
5760         int err;
5761 
5762         file = kzalloc(sizeof(*file), GFP_NOIO);
5763         if (!file)
5764                 return -ENOMEM;
5765 
5766         err = 0;
5767         spin_lock(&mddev->lock);
5768         /* bitmap disabled, zero the first byte and copy out */
5769         if (!mddev->bitmap_info.file)
5770                 file->pathname[0] = '\0';
5771         else if ((ptr = file_path(mddev->bitmap_info.file,
5772                                file->pathname, sizeof(file->pathname))),
5773                  IS_ERR(ptr))
5774                 err = PTR_ERR(ptr);
5775         else
5776                 memmove(file->pathname, ptr,
5777                         sizeof(file->pathname)-(ptr-file->pathname));
5778         spin_unlock(&mddev->lock);
5779 
5780         if (err == 0 &&
5781             copy_to_user(arg, file, sizeof(*file)))
5782                 err = -EFAULT;
5783 
5784         kfree(file);
5785         return err;
5786 }
5787 
5788 static int get_disk_info(struct mddev *mddev, void __user * arg)
5789 {
5790         mdu_disk_info_t info;
5791         struct md_rdev *rdev;
5792 
5793         if (copy_from_user(&info, arg, sizeof(info)))
5794                 return -EFAULT;
5795 
5796         rcu_read_lock();
5797         rdev = md_find_rdev_nr_rcu(mddev, info.number);
5798         if (rdev) {
5799                 info.major = MAJOR(rdev->bdev->bd_dev);
5800                 info.minor = MINOR(rdev->bdev->bd_dev);
5801                 info.raid_disk = rdev->raid_disk;
5802                 info.state = 0;
5803                 if (test_bit(Faulty, &rdev->flags))
5804                         info.state |= (1<<MD_DISK_FAULTY);
5805                 else if (test_bit(In_sync, &rdev->flags)) {
5806                         info.state |= (1<<MD_DISK_ACTIVE);
5807                         info.state |= (1<<MD_DISK_SYNC);
5808                 }
5809                 if (test_bit(WriteMostly, &rdev->flags))
5810                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
5811         } else {
5812                 info.major = info.minor = 0;
5813                 info.raid_disk = -1;
5814                 info.state = (1<<MD_DISK_REMOVED);
5815         }
5816         rcu_read_unlock();
5817 
5818         if (copy_to_user(arg, &info, sizeof(info)))
5819                 return -EFAULT;
5820 
5821         return 0;
5822 }
5823 
5824 static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
5825 {
5826         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5827         struct md_rdev *rdev;
5828         dev_t dev = MKDEV(info->major,info->minor);
5829 
5830         if (mddev_is_clustered(mddev) &&
5831                 !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
5832                 pr_err("%s: Cannot add to clustered mddev.\n",
5833                                mdname(mddev));
5834                 return -EINVAL;
5835         }
5836 
5837         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5838                 return -EOVERFLOW;
5839 
5840         if (!mddev->raid_disks) {
5841                 int err;
5842                 /* expecting a device which has a superblock */
5843                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5844                 if (IS_ERR(rdev)) {
5845                         printk(KERN_WARNING
5846                                 "md: md_import_device returned %ld\n",
5847                                 PTR_ERR(rdev));
5848                         return PTR_ERR(rdev);
5849                 }
5850                 if (!list_empty(&mddev->disks)) {
5851                         struct md_rdev *rdev0
5852                                 = list_entry(mddev->disks.next,
5853                                              struct md_rdev, same_set);
5854                         err = super_types[mddev->major_version]
5855                                 .load_super(rdev, rdev0, mddev->minor_version);
5856                         if (err < 0) {
5857                                 printk(KERN_WARNING
5858                                         "md: %s has different UUID to %s\n",
5859                                         bdevname(rdev->bdev,b),
5860                                         bdevname(rdev0->bdev,b2));
5861                                 export_rdev(rdev);
5862                                 return -EINVAL;
5863                         }
5864                 }
5865                 err = bind_rdev_to_array(rdev, mddev);
5866                 if (err)
5867                         export_rdev(rdev);
5868                 return err;
5869         }
5870 
5871         /*
5872          * add_new_disk can be used once the array is assembled
5873          * to add "hot spares".  They must already have a superblock
5874          * written
5875          */
5876         if (mddev->pers) {
5877                 int err;
5878                 if (!mddev->pers->hot_add_disk) {
5879                         printk(KERN_WARNING
5880                                 "%s: personality does not support diskops!\n",
5881                                mdname(mddev));
5882                         return -EINVAL;
5883                 }
5884                 if (mddev->persistent)
5885                         rdev = md_import_device(dev, mddev->major_version,
5886                                                 mddev->minor_version);
5887                 else
5888                         rdev = md_import_device(dev, -1, -1);
5889                 if (IS_ERR(rdev)) {
5890                         printk(KERN_WARNING
5891                                 "md: md_import_device returned %ld\n",
5892                                 PTR_ERR(rdev));
5893                         return PTR_ERR(rdev);
5894                 }
5895                 /* set saved_raid_disk if appropriate */
5896                 if (!mddev->persistent) {
5897                         if (info->state & (1<<MD_DISK_SYNC)  &&
5898                             info->raid_disk < mddev->raid_disks) {
5899                                 rdev->raid_disk = info->raid_disk;
5900                                 set_bit(In_sync, &rdev->flags);
5901                                 clear_bit(Bitmap_sync, &rdev->flags);
5902                         } else
5903                                 rdev->raid_disk = -1;
5904                         rdev->saved_raid_disk = rdev->raid_disk;
5905                 } else
5906                         super_types[mddev->major_version].
5907                                 validate_super(mddev, rdev);
5908                 if ((info->state & (1<<MD_DISK_SYNC)) &&
5909                      rdev->raid_disk != info->raid_disk) {
5910                         /* This was a hot-add request, but events doesn't
5911                          * match, so reject it.
5912                          */
5913                         export_rdev(rdev);
5914                         return -EINVAL;
5915                 }
5916 
5917                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
5918                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5919                         set_bit(WriteMostly, &rdev->flags);
5920                 else
5921                         clear_bit(WriteMostly, &rdev->flags);
5922 
5923                 /*
5924                  * check whether the device shows up in other nodes
5925                  */
5926                 if (mddev_is_clustered(mddev)) {
5927                         if (info->state & (1 << MD_DISK_CANDIDATE)) {
5928                                 /* Through --cluster-confirm */
5929                                 set_bit(Candidate, &rdev->flags);
5930                                 err = md_cluster_ops->new_disk_ack(mddev, true);
5931                                 if (err) {
5932                                         export_rdev(rdev);
5933                                         return err;
5934                                 }
5935                         } else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
5936                                 /* --add initiated by this node */
5937                                 err = md_cluster_ops->add_new_disk_start(mddev, rdev);
5938                                 if (err) {
5939                                         md_cluster_ops->add_new_disk_finish(mddev);
5940                                         export_rdev(rdev);
5941                                         return err;
5942                                 }
5943                         }
5944                 }
5945 
5946                 rdev->raid_disk = -1;
5947                 err = bind_rdev_to_array(rdev, mddev);
5948                 if (err)
5949                         export_rdev(rdev);
5950                 else
5951                         err = add_bound_rdev(rdev);
5952                 if (mddev_is_clustered(mddev) &&
5953                                 (info->state & (1 << MD_DISK_CLUSTER_ADD)))
5954                         md_cluster_ops->add_new_disk_finish(mddev);
5955                 return err;
5956         }
5957 
5958         /* otherwise, add_new_disk is only allowed
5959          * for major_version==0 superblocks
5960          */
5961         if (mddev->major_version != 0) {
5962                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5963                        mdname(mddev));
5964                 return -EINVAL;
5965         }
5966 
5967         if (!(info->state & (1<<MD_DISK_FAULTY))) {
5968                 int err;
5969                 rdev = md_import_device(dev, -1, 0);
5970                 if (IS_ERR(rdev)) {
5971                         printk(KERN_WARNING
5972                                 "md: error, md_import_device() returned %ld\n",
5973                                 PTR_ERR(rdev));
5974                         return PTR_ERR(rdev);
5975                 }
5976                 rdev->desc_nr = info->number;
5977                 if (info->raid_disk < mddev->raid_disks)
5978                         rdev->raid_disk = info->raid_disk;
5979                 else
5980                         rdev->raid_disk = -1;
5981 
5982                 if (rdev->raid_disk < mddev->raid_disks)
5983                         if (info->state & (1<<MD_DISK_SYNC))
5984                                 set_bit(In_sync, &rdev->flags);
5985 
5986                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5987                         set_bit(WriteMostly, &rdev->flags);
5988 
5989                 if (!mddev->persistent) {
5990                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
5991                         rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5992                 } else
5993                         rdev->sb_start = calc_dev_sboffset(rdev);
5994                 rdev->sectors = rdev->sb_start;
5995 
5996                 err = bind_rdev_to_array(rdev, mddev);
5997                 if (err) {
5998                         export_rdev(rdev);
5999                         return err;
6000                 }
6001         }
6002 
6003         return 0;
6004 }
6005 
6006 static int hot_remove_disk(struct mddev *mddev, dev_t dev)
6007 {
6008         char b[BDEVNAME_SIZE];
6009         struct md_rdev *rdev;
6010 
6011         rdev = find_rdev(mddev, dev);
6012         if (!rdev)
6013                 return -ENXIO;
6014 
6015         if (mddev_is_clustered(mddev))
6016                 md_cluster_ops->metadata_update_start(mddev);
6017 
6018         clear_bit(Blocked, &rdev->flags);
6019         remove_and_add_spares(mddev, rdev);
6020 
6021         if (rdev->raid_disk >= 0)
6022                 goto busy;
6023 
6024         if (mddev_is_clustered(mddev))
6025                 md_cluster_ops->remove_disk(mddev, rdev);
6026 
6027         md_kick_rdev_from_array(rdev);
6028         md_update_sb(mddev, 1);
6029         md_new_event(mddev);
6030 
6031         if (mddev_is_clustered(mddev))
6032                 md_cluster_ops->metadata_update_finish(mddev);
6033 
6034         return 0;
6035 busy:
6036         if (mddev_is_clustered(mddev))
6037                 md_cluster_ops->metadata_update_cancel(mddev);
6038         printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
6039                 bdevname(rdev->bdev,b), mdname(mddev));
6040         return -EBUSY;
6041 }
6042 
6043 static int hot_add_disk(struct mddev *mddev, dev_t dev)
6044 {
6045         char b[BDEVNAME_SIZE];
6046         int err;
6047         struct md_rdev *rdev;
6048 
6049         if (!mddev->pers)
6050                 return -ENODEV;
6051 
6052         if (mddev->major_version != 0) {
6053                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
6054                         " version-0 superblocks.\n",
6055                         mdname(mddev));
6056                 return -EINVAL;
6057         }
6058         if (!mddev->pers->hot_add_disk) {
6059                 printk(KERN_WARNING
6060                         "%s: personality does not support diskops!\n",
6061                         mdname(mddev));
6062                 return -EINVAL;
6063         }
6064 
6065         rdev = md_import_device(dev, -1, 0);
6066         if (IS_ERR(rdev)) {
6067                 printk(KERN_WARNING
6068                         "md: error, md_import_device() returned %ld\n",
6069                         PTR_ERR(rdev));
6070                 return -EINVAL;
6071         }
6072 
6073         if (mddev->persistent)
6074                 rdev->sb_start = calc_dev_sboffset(rdev);
6075         else
6076                 rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
6077 
6078         rdev->sectors = rdev->sb_start;
6079 
6080         if (test_bit(Faulty, &rdev->flags)) {
6081                 printk(KERN_WARNING
6082                         "md: can not hot-add faulty %s disk to %s!\n",
6083                         bdevname(rdev->bdev,b), mdname(mddev));
6084                 err = -EINVAL;
6085                 goto abort_export;
6086         }
6087 
6088         if (mddev_is_clustered(mddev))
6089                 md_cluster_ops->metadata_update_start(mddev);
6090         clear_bit(In_sync, &rdev->flags);
6091         rdev->desc_nr = -1;
6092         rdev->saved_raid_disk = -1;
6093         err = bind_rdev_to_array(rdev, mddev);
6094         if (err)
6095                 goto abort_clustered;
6096 
6097         /*
6098          * The rest should better be atomic, we can have disk failures
6099          * noticed in interrupt contexts ...
6100          */
6101 
6102         rdev->raid_disk = -1;
6103 
6104         md_update_sb(mddev, 1);
6105 
6106         if (mddev_is_clustered(mddev))
6107                 md_cluster_ops->metadata_update_finish(mddev);
6108         /*
6109          * Kick recovery, maybe this spare has to be added to the
6110          * array immediately.
6111          */
6112         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6113         md_wakeup_thread(mddev->thread);
6114         md_new_event(mddev);
6115         return 0;
6116 
6117 abort_clustered:
6118         if (mddev_is_clustered(mddev))
6119                 md_cluster_ops->metadata_update_cancel(mddev);
6120 abort_export:
6121         export_rdev(rdev);
6122         return err;
6123 }
6124 
6125 static int set_bitmap_file(struct mddev *mddev, int fd)
6126 {
6127         int err = 0;
6128 
6129         if (mddev->pers) {
6130                 if (!mddev->pers->quiesce || !mddev->thread)
6131                         return -EBUSY;
6132                 if (mddev->recovery || mddev->sync_thread)
6133                         return -EBUSY;
6134                 /* we should be able to change the bitmap.. */
6135         }
6136 
6137         if (fd >= 0) {
6138                 struct inode *inode;
6139                 struct file *f;
6140 
6141                 if (mddev->bitmap || mddev->bitmap_info.file)
6142                         return -EEXIST; /* cannot add when bitmap is present */
6143                 f = fget(fd);
6144 
6145                 if (f == NULL) {
6146                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
6147                                mdname(mddev));
6148                         return -EBADF;
6149                 }
6150 
6151                 inode = f->f_mapping->host;
6152                 if (!S_ISREG(inode->i_mode)) {
6153                         printk(KERN_ERR "%s: error: bitmap file must be a regular file\n",
6154                                mdname(mddev));
6155                         err = -EBADF;
6156                 } else if (!(f->f_mode & FMODE_WRITE)) {
6157                         printk(KERN_ERR "%s: error: bitmap file must open for write\n",
6158                                mdname(mddev));
6159                         err = -EBADF;
6160                 } else if (atomic_read(&inode->i_writecount) != 1) {
6161                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
6162                                mdname(mddev));
6163                         err = -EBUSY;
6164                 }
6165                 if (err) {
6166                         fput(f);
6167                         return err;
6168                 }
6169                 mddev->bitmap_info.file = f;
6170                 mddev->bitmap_info.offset = 0; /* file overrides offset */
6171         } else if (mddev->bitmap == NULL)
6172                 return -ENOENT; /* cannot remove what isn't there */
6173         err = 0;
6174         if (mddev->pers) {
6175                 mddev->pers->quiesce(mddev, 1);
6176                 if (fd >= 0) {
6177                         struct bitmap *bitmap;
6178 
6179                         bitmap = bitmap_create(mddev, -1);
6180                         if (!IS_ERR(bitmap)) {
6181                                 mddev->bitmap = bitmap;
6182                                 err = bitmap_load(mddev);
6183                         } else
6184                                 err = PTR_ERR(bitmap);
6185                 }
6186                 if (fd < 0 || err) {
6187                         bitmap_destroy(mddev);
6188                         fd = -1; /* make sure to put the file */
6189                 }
6190                 mddev->pers->quiesce(mddev, 0);
6191         }
6192         if (fd < 0) {
6193                 struct file *f = mddev->bitmap_info.file;
6194                 if (f) {
6195                         spin_lock(&mddev->lock);
6196                         mddev->bitmap_info.file = NULL;
6197                         spin_unlock(&mddev->lock);
6198                         fput(f);
6199                 }
6200         }
6201 
6202         return err;
6203 }
6204 
6205 /*
6206  * set_array_info is used two different ways
6207  * The original usage is when creating a new array.
6208  * In this usage, raid_disks is > 0 and it together with
6209  *  level, size, not_persistent,layout,chunksize determine the
6210  *  shape of the array.
6211  *  This will always create an array with a type-0.90.0 superblock.
6212  * The newer usage is when assembling an array.
6213  *  In this case raid_disks will be 0, and the major_version field is
6214  *  use to determine which style super-blocks are to be found on the devices.
6215  *  The minor and patch _version numbers are also kept incase the
6216  *  super_block handler wishes to interpret them.
6217  */
6218 static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
6219 {
6220 
6221         if (info->raid_disks == 0) {
6222                 /* just setting version number for superblock loading */
6223                 if (info->major_version < 0 ||
6224                     info->major_version >= ARRAY_SIZE(super_types) ||
6225                     super_types[info->major_version].name == NULL) {
6226                         /* maybe try to auto-load a module? */
6227                         printk(KERN_INFO
6228                                 "md: superblock version %d not known\n",
6229                                 info->major_version);
6230                         return -EINVAL;
6231                 }
6232                 mddev->major_version = info->major_version;
6233                 mddev->minor_version = info->minor_version;
6234                 mddev->patch_version = info->patch_version;
6235                 mddev->persistent = !info->not_persistent;
6236                 /* ensure mddev_put doesn't delete this now that there
6237                  * is some minimal configuration.
6238                  */
6239                 mddev->ctime         = get_seconds();
6240                 return 0;
6241         }
6242         mddev->major_version = MD_MAJOR_VERSION;
6243         mddev->minor_version = MD_MINOR_VERSION;
6244         mddev->patch_version = MD_PATCHLEVEL_VERSION;
6245         mddev->ctime         = get_seconds();
6246 
6247         mddev->level         = info->level;
6248         mddev->clevel[0]     = 0;
6249         mddev->dev_sectors   = 2 * (sector_t)info->size;
6250         mddev->raid_disks    = info->raid_disks;
6251         /* don't set md_minor, it is determined by which /dev/md* was
6252          * openned
6253          */
6254         if (info->state & (1<<MD_SB_CLEAN))
6255                 mddev->recovery_cp = MaxSector;
6256         else
6257                 mddev->recovery_cp = 0;
6258         mddev->persistent    = ! info->not_persistent;
6259         mddev->external      = 0;
6260 
6261         mddev->layout        = info->layout;
6262         mddev->chunk_sectors = info->chunk_size >> 9;
6263 
6264         mddev->max_disks     = MD_SB_DISKS;
6265 
6266         if (mddev->persistent)
6267                 mddev->flags         = 0;
6268         set_bit(MD_CHANGE_DEVS, &mddev->flags);
6269 
6270         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6271         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6272         mddev->bitmap_info.offset = 0;
6273 
6274         mddev->reshape_position = MaxSector;
6275 
6276         /*
6277          * Generate a 128 bit UUID
6278          */
6279         get_random_bytes(mddev->uuid, 16);
6280 
6281         mddev->new_level = mddev->level;
6282         mddev->new_chunk_sectors = mddev->chunk_sectors;
6283         mddev->new_layout = mddev->layout;
6284         mddev->delta_disks = 0;
6285         mddev->reshape_backwards = 0;
6286 
6287         return 0;
6288 }
6289 
6290 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6291 {
6292         WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6293 
6294         if (mddev->external_size)
6295                 return;
6296 
6297         mddev->array_sectors = array_sectors;
6298 }
6299 EXPORT_SYMBOL(md_set_array_sectors);
6300 
6301 static int update_size(struct mddev *mddev, sector_t num_sectors)
6302 {
6303         struct md_rdev *rdev;
6304         int rv;
6305         int fit = (num_sectors == 0);
6306 
6307         if (mddev->pers->resize == NULL)
6308                 return -EINVAL;
6309         /* The "num_sectors" is the number of sectors of each device that
6310          * is used.  This can only make sense for arrays with redundancy.
6311          * linear and raid0 always use whatever space is available. We can only
6312          * consider changing this number if no resync or reconstruction is
6313          * happening, and if the new size is acceptable. It must fit before the
6314          * sb_start or, if that is <data_offset, it must fit before the size
6315          * of each device.  If num_sectors is zero, we find the largest size
6316          * that fits.
6317          */
6318         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6319             mddev->sync_thread)
6320                 return -EBUSY;
6321         if (mddev->ro)
6322                 return -EROFS;
6323 
6324         rdev_for_each(rdev, mddev) {
6325                 sector_t avail = rdev->sectors;
6326 
6327                 if (fit && (num_sectors == 0 || num_sectors > avail))
6328                         num_sectors = avail;
6329                 if (avail < num_sectors)
6330                         return -ENOSPC;
6331         }
6332         rv = mddev->pers->resize(mddev, num_sectors);
6333         if (!rv)
6334                 revalidate_disk(mddev->gendisk);
6335         return rv;
6336 }
6337 
6338 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6339 {
6340         int rv;
6341         struct md_rdev *rdev;
6342         /* change the number of raid disks */
6343         if (mddev->pers->check_reshape == NULL)
6344                 return -EINVAL;
6345         if (mddev->ro)
6346                 return -EROFS;
6347         if (raid_disks <= 0 ||
6348             (mddev->max_disks && raid_disks >= mddev->max_disks))
6349                 return -EINVAL;
6350         if (mddev->sync_thread ||
6351             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6352             mddev->reshape_position != MaxSector)
6353                 return -EBUSY;
6354 
6355         rdev_for_each(rdev, mddev) {
6356                 if (mddev->raid_disks < raid_disks &&
6357                     rdev->data_offset < rdev->new_data_offset)
6358                         return -EINVAL;
6359                 if (mddev->raid_disks > raid_disks &&
6360                     rdev->data_offset > rdev->new_data_offset)
6361                         return -EINVAL;
6362         }
6363 
6364         mddev->delta_disks = raid_disks - mddev->raid_disks;
6365         if (mddev->delta_disks < 0)
6366                 mddev->reshape_backwards = 1;
6367         else if (mddev->delta_disks > 0)
6368                 mddev->reshape_backwards = 0;
6369 
6370         rv = mddev->pers->check_reshape(mddev);
6371         if (rv < 0) {
6372                 mddev->delta_disks = 0;
6373                 mddev->reshape_backwards = 0;
6374         }
6375         return rv;
6376 }
6377 
6378 /*
6379  * update_array_info is used to change the configuration of an
6380  * on-line array.
6381  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6382  * fields in the info are checked against the array.
6383  * Any differences that cannot be handled will cause an error.
6384  * Normally, only one change can be managed at a time.
6385  */
6386 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6387 {
6388         int rv = 0;
6389         int cnt = 0;
6390         int state = 0;
6391 
6392         /* calculate expected state,ignoring low bits */
6393         if (mddev->bitmap && mddev->bitmap_info.offset)
6394                 state |= (1 << MD_SB_BITMAP_PRESENT);
6395 
6396         if (mddev->major_version != info->major_version ||
6397             mddev->minor_version != info->minor_version ||
6398 /*          mddev->patch_version != info->patch_version || */
6399             mddev->ctime         != info->ctime         ||
6400             mddev->level         != info->level         ||
6401 /*          mddev->layout        != info->layout        || */
6402             mddev->persistent    != !info->not_persistent ||
6403             mddev->chunk_sectors != info->chunk_size >> 9 ||
6404             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6405             ((state^info->state) & 0xfffffe00)
6406                 )
6407                 return -EINVAL;
6408         /* Check there is only one change */
6409         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6410                 cnt++;
6411         if (mddev->raid_disks != info->raid_disks)
6412                 cnt++;
6413         if (mddev->layout != info->layout)
6414                 cnt++;
6415         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6416                 cnt++;
6417         if (cnt == 0)
6418                 return 0;
6419         if (cnt > 1)
6420                 return -EINVAL;
6421 
6422         if (mddev->layout != info->layout) {
6423                 /* Change layout
6424                  * we don't need to do anything at the md level, the
6425                  * personality will take care of it all.
6426                  */
6427                 if (mddev->pers->check_reshape == NULL)
6428                         return -EINVAL;
6429                 else {
6430                         mddev->new_layout = info->layout;
6431                         rv = mddev->pers->check_reshape(mddev);
6432                         if (rv)
6433                                 mddev->new_layout = mddev->layout;
6434                         return rv;
6435                 }
6436         }
6437         if (mddev_is_clustered(mddev))
6438                 md_cluster_ops->metadata_update_start(mddev);
6439         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6440                 rv = update_size(mddev, (sector_t)info->size * 2);
6441 
6442         if (mddev->raid_disks    != info->raid_disks)
6443                 rv = update_raid_disks(mddev, info->raid_disks);
6444 
6445         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6446                 if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
6447                         rv = -EINVAL;
6448                         goto err;
6449                 }
6450                 if (mddev->recovery || mddev->sync_thread) {
6451                         rv = -EBUSY;
6452                         goto err;
6453                 }
6454                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6455                         struct bitmap *bitmap;
6456                         /* add the bitmap */
6457                         if (mddev->bitmap) {
6458                                 rv = -EEXIST;
6459                                 goto err;
6460                         }
6461                         if (mddev->bitmap_info.default_offset == 0) {
6462                                 rv = -EINVAL;
6463                                 goto err;
6464                         }
6465                         mddev->bitmap_info.offset =
6466                                 mddev->bitmap_info.default_offset;
6467                         mddev->bitmap_info.space =
6468                                 mddev->bitmap_info.default_space;
6469                         mddev->pers->quiesce(mddev, 1);
6470                         bitmap = bitmap_create(mddev, -1);
6471                         if (!IS_ERR(bitmap)) {
6472                                 mddev->bitmap = bitmap;
6473                                 rv = bitmap_load(mddev);
6474                         } else
6475                                 rv = PTR_ERR(bitmap);
6476                         if (rv)
6477                                 bitmap_destroy(mddev);
6478                         mddev->pers->quiesce(mddev, 0);
6479                 } else {
6480                         /* remove the bitmap */
6481                         if (!mddev->bitmap) {
6482                                 rv = -ENOENT;
6483                                 goto err;
6484                         }
6485                         if (mddev->bitmap->storage.file) {
6486                                 rv = -EINVAL;
6487                                 goto err;
6488                         }
6489                         mddev->pers->quiesce(mddev, 1);
6490                         bitmap_destroy(mddev);
6491                         mddev->pers->quiesce(mddev, 0);
6492                         mddev->bitmap_info.offset = 0;
6493                 }
6494         }
6495         md_update_sb(mddev, 1);
6496         if (mddev_is_clustered(mddev))
6497                 md_cluster_ops->metadata_update_finish(mddev);
6498         return rv;
6499 err:
6500         if (mddev_is_clustered(mddev))
6501                 md_cluster_ops->metadata_update_cancel(mddev);
6502         return rv;
6503 }
6504 
6505 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6506 {
6507         struct md_rdev *rdev;
6508         int err = 0;
6509 
6510         if (mddev->pers == NULL)
6511                 return -ENODEV;
6512 
6513         rcu_read_lock();
6514         rdev = find_rdev_rcu(mddev, dev);
6515         if (!rdev)
6516                 err =  -ENODEV;
6517         else {
6518                 md_error(mddev, rdev);
6519                 if (!test_bit(Faulty, &rdev->flags))
6520                         err = -EBUSY;
6521         }
6522         rcu_read_unlock();
6523         return err;
6524 }
6525 
6526 /*
6527  * We have a problem here : there is no easy way to give a CHS
6528  * virtual geometry. We currently pretend that we have a 2 heads
6529  * 4 sectors (with a BIG number of cylinders...). This drives
6530  * dosfs just mad... ;-)
6531  */
6532 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6533 {
6534         struct mddev *mddev = bdev->bd_disk->private_data;
6535 
6536         geo->heads = 2;
6537         geo->sectors = 4;
6538         geo->cylinders = mddev->array_sectors / 8;
6539         return 0;
6540 }
6541 
6542 static inline bool md_ioctl_valid(unsigned int cmd)
6543 {
6544         switch (cmd) {
6545         case ADD_NEW_DISK:
6546         case BLKROSET:
6547         case GET_ARRAY_INFO:
6548         case GET_BITMAP_FILE:
6549         case GET_DISK_INFO:
6550         case HOT_ADD_DISK:
6551         case HOT_REMOVE_DISK:
6552         case RAID_AUTORUN:
6553         case RAID_VERSION:
6554         case RESTART_ARRAY_RW:
6555         case RUN_ARRAY:
6556         case SET_ARRAY_INFO:
6557         case SET_BITMAP_FILE:
6558         case SET_DISK_FAULTY:
6559         case STOP_ARRAY:
6560         case STOP_ARRAY_RO:
6561         case CLUSTERED_DISK_NACK:
6562                 return true;
6563         default:
6564                 return false;
6565         }
6566 }
6567 
6568 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6569                         unsigned int cmd, unsigned long arg)
6570 {
6571         int err = 0;
6572         void __user *argp = (void __user *)arg;
6573         struct mddev *mddev = NULL;
6574         int ro;
6575 
6576         if (!md_ioctl_valid(cmd))
6577                 return -ENOTTY;
6578 
6579         switch (cmd) {
6580         case RAID_VERSION:
6581         case GET_ARRAY_INFO:
6582         case GET_DISK_INFO:
6583                 break;
6584         default:
6585                 if (!capable(CAP_SYS_ADMIN))
6586                         return -EACCES;
6587         }
6588 
6589         /*
6590          * Commands dealing with the RAID driver but not any
6591          * particular array:
6592          */
6593         switch (cmd) {
6594         case RAID_VERSION:
6595                 err = get_version(argp);
6596                 goto out;
6597 
6598 #ifndef MODULE
6599         case RAID_AUTORUN:
6600                 err = 0;
6601                 autostart_arrays(arg);
6602                 goto out;
6603 #endif
6604         default:;
6605         }
6606 
6607         /*
6608          * Commands creating/starting a new array:
6609          */
6610 
6611         mddev = bdev->bd_disk->private_data;
6612 
6613         if (!mddev) {
6614                 BUG();
6615                 goto out;
6616         }
6617 
6618         /* Some actions do not requires the mutex */
6619         switch (cmd) {
6620         case GET_ARRAY_INFO:
6621                 if (!mddev->raid_disks && !mddev->external)
6622                         err = -ENODEV;
6623                 else
6624                         err = get_array_info(mddev, argp);
6625                 goto out;
6626 
6627         case GET_DISK_INFO:
6628                 if (!mddev->raid_disks && !mddev->external)
6629                         err = -ENODEV;
6630                 else
6631                         err = get_disk_info(mddev, argp);
6632                 goto out;
6633 
6634         case SET_DISK_FAULTY:
6635                 err = set_disk_faulty(mddev, new_decode_dev(arg));
6636                 goto out;
6637 
6638         case GET_BITMAP_FILE:
6639                 err = get_bitmap_file(mddev, argp);
6640                 goto out;
6641 
6642         }
6643 
6644         if (cmd == ADD_NEW_DISK)
6645                 /* need to ensure md_delayed_delete() has completed */
6646                 flush_workqueue(md_misc_wq);
6647 
6648         if (cmd == HOT_REMOVE_DISK)
6649                 /* need to ensure recovery thread has run */
6650                 wait_event_interruptible_timeout(mddev->sb_wait,
6651                                                  !test_bit(MD_RECOVERY_NEEDED,
6652                                                            &mddev->flags),
6653                                                  msecs_to_jiffies(5000));
6654         if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
6655                 /* Need to flush page cache, and ensure no-one else opens
6656                  * and writes
6657                  */
6658                 mutex_lock(&mddev->open_mutex);
6659                 if (mddev->pers && atomic_read(&mddev->openers) > 1) {
6660                         mutex_unlock(&mddev->open_mutex);
6661                         err = -EBUSY;
6662                         goto out;
6663                 }
6664                 set_bit(MD_STILL_CLOSED, &mddev->flags);
6665                 mutex_unlock(&mddev->open_mutex);
6666                 sync_blockdev(bdev);
6667         }
6668         err = mddev_lock(mddev);
6669         if (err) {
6670                 printk(KERN_INFO
6671                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
6672                         err, cmd);
6673                 goto out;
6674         }
6675 
6676         if (cmd == SET_ARRAY_INFO) {
6677                 mdu_array_info_t info;
6678                 if (!arg)
6679                         memset(&info, 0, sizeof(info));
6680                 else if (copy_from_user(&info, argp, sizeof(info))) {
6681                         err = -EFAULT;
6682                         goto unlock;
6683                 }
6684                 if (mddev->pers) {
6685                         err = update_array_info(mddev, &info);
6686                         if (err) {
6687                                 printk(KERN_WARNING "md: couldn't update"
6688                                        " array info. %d\n", err);
6689                                 goto unlock;
6690                         }
6691                         goto unlock;
6692                 }
6693                 if (!list_empty(&mddev->disks)) {
6694                         printk(KERN_WARNING
6695                                "md: array %s already has disks!\n",
6696                                mdname(mddev));
6697                         err = -EBUSY;
6698                         goto unlock;
6699                 }
6700                 if (mddev->raid_disks) {
6701                         printk(KERN_WARNING
6702                                "md: array %s already initialised!\n",
6703                                mdname(mddev));
6704                         err = -EBUSY;
6705                         goto unlock;
6706                 }
6707                 err = set_array_info(mddev, &info);
6708                 if (err) {
6709                         printk(KERN_WARNING "md: couldn't set"
6710                                " array info. %d\n", err);
6711                         goto unlock;
6712                 }
6713                 goto unlock;
6714         }
6715 
6716         /*
6717          * Commands querying/configuring an existing array:
6718          */
6719         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6720          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6721         if ((!mddev->raid_disks && !mddev->external)
6722             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6723             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6724             && cmd != GET_BITMAP_FILE) {
6725                 err = -ENODEV;
6726                 goto unlock;
6727         }
6728 
6729         /*
6730          * Commands even a read-only array can execute:
6731          */
6732         switch (cmd) {
6733         case RESTART_ARRAY_RW:
6734                 err = restart_array(mddev);
6735                 goto unlock;
6736 
6737         case STOP_ARRAY:
6738                 err = do_md_stop(mddev, 0, bdev);
6739                 goto unlock;
6740 
6741         case STOP_ARRAY_RO:
6742                 err = md_set_readonly(mddev, bdev);
6743                 goto unlock;
6744 
6745         case HOT_REMOVE_DISK:
6746                 err = hot_remove_disk(mddev, new_decode_dev(arg));
6747                 goto unlock;
6748 
6749         case ADD_NEW_DISK:
6750                 /* We can support ADD_NEW_DISK on read-only arrays
6751                  * on if we are re-adding a preexisting device.
6752                  * So require mddev->pers and MD_DISK_SYNC.
6753                  */
6754                 if (mddev->pers) {
6755                         mdu_disk_info_t info;
6756                         if (copy_from_user(&info, argp, sizeof(info)))
6757                                 err = -EFAULT;
6758                         else if (!(info.state & (1<<MD_DISK_SYNC)))
6759                                 /* Need to clear read-only for this */
6760                                 break;
6761                         else
6762                                 err = add_new_disk(mddev, &info);
6763                         goto unlock;
6764                 }
6765                 break;
6766 
6767         case BLKROSET:
6768                 if (get_user(ro, (int __user *)(arg))) {
6769                         err = -EFAULT;
6770                         goto unlock;
6771                 }
6772                 err = -EINVAL;
6773 
6774                 /* if the bdev is going readonly the value of mddev->ro
6775                  * does not matter, no writes are coming
6776                  */
6777                 if (ro)
6778                         goto unlock;
6779 
6780                 /* are we are already prepared for writes? */
6781                 if (mddev->ro != 1)
6782                         goto unlock;
6783 
6784                 /* transitioning to readauto need only happen for
6785                  * arrays that call md_write_start
6786                  */
6787                 if (mddev->pers) {
6788                         err = restart_array(mddev);
6789                         if (err == 0) {
6790                                 mddev->ro = 2;
6791                                 set_disk_ro(mddev->gendisk, 0);
6792                         }
6793                 }
6794                 goto unlock;
6795         }
6796 
6797         /*
6798          * The remaining ioctls are changing the state of the
6799          * superblock, so we do not allow them on read-only arrays.
6800          */
6801         if (mddev->ro && mddev->pers) {
6802                 if (mddev->ro == 2) {
6803                         mddev->ro = 0;
6804                         sysfs_notify_dirent_safe(mddev->sysfs_state);
6805                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6806                         /* mddev_unlock will wake thread */
6807                         /* If a device failed while we were read-only, we
6808                          * need to make sure the metadata is updated now.
6809                          */
6810                         if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
6811                                 mddev_unlock(mddev);
6812                                 wait_event(mddev->sb_wait,
6813                                            !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
6814                                            !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6815                                 mddev_lock_nointr(mddev);
6816                         }
6817                 } else {
6818                         err = -EROFS;
6819                         goto unlock;
6820                 }
6821         }
6822 
6823         switch (cmd) {
6824         case ADD_NEW_DISK:
6825         {
6826                 mdu_disk_info_t info;
6827                 if (copy_from_user(&info, argp, sizeof(info)))
6828                         err = -EFAULT;
6829                 else
6830                         err = add_new_disk(mddev, &info);
6831                 goto unlock;
6832         }
6833 
6834         case CLUSTERED_DISK_NACK:
6835                 if (mddev_is_clustered(mddev))
6836                         md_cluster_ops->new_disk_ack(mddev, false);
6837                 else
6838                         err = -EINVAL;
6839                 goto unlock;
6840 
6841         case HOT_ADD_DISK:
6842                 err = hot_add_disk(mddev, new_decode_dev(arg));
6843                 goto unlock;
6844 
6845         case RUN_ARRAY:
6846                 err = do_md_run(mddev);
6847                 goto unlock;
6848 
6849         case SET_BITMAP_FILE:
6850                 err = set_bitmap_file(mddev, (int)arg);
6851                 goto unlock;
6852 
6853         default:
6854                 err = -EINVAL;
6855                 goto unlock;
6856         }
6857 
6858 unlock:
6859         if (mddev->hold_active == UNTIL_IOCTL &&
6860             err != -EINVAL)
6861                 mddev->hold_active = 0;
6862         mddev_unlock(mddev);
6863 out:
6864         return err;
6865 }
6866 #ifdef CONFIG_COMPAT
6867 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6868                     unsigned int cmd, unsigned long arg)
6869 {
6870         switch (cmd) {
6871         case HOT_REMOVE_DISK:
6872         case HOT_ADD_DISK:
6873         case SET_DISK_FAULTY:
6874         case SET_BITMAP_FILE:
6875                 /* These take in integer arg, do not convert */
6876                 break;
6877         default:
6878                 arg = (unsigned long)compat_ptr(arg);
6879                 break;
6880         }
6881 
6882         return md_ioctl(bdev, mode, cmd, arg);
6883 }
6884 #endif /* CONFIG_COMPAT */
6885 
6886 static int md_open(struct block_device *bdev, fmode_t mode)
6887 {
6888         /*
6889          * Succeed if we can lock the mddev, which confirms that
6890          * it isn't being stopped right now.
6891          */
6892         struct mddev *mddev = mddev_find(bdev->bd_dev);
6893         int err;
6894 
6895         if (!mddev)
6896                 return -ENODEV;
6897 
6898         if (mddev->gendisk != bdev->bd_disk) {
6899                 /* we are racing with mddev_put which is discarding this
6900                  * bd_disk.
6901                  */
6902                 mddev_put(mddev);
6903                 /* Wait until bdev->bd_disk is definitely gone */
6904                 flush_workqueue(md_misc_wq);
6905                 /* Then retry the open from the top */
6906                 return -ERESTARTSYS;
6907         }
6908         BUG_ON(mddev != bdev->bd_disk->private_data);
6909 
6910         if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6911                 goto out;
6912 
6913         err = 0;
6914         atomic_inc(&mddev->openers);
6915         clear_bit(MD_STILL_CLOSED, &mddev->flags);
6916         mutex_unlock(&mddev->open_mutex);
6917 
6918         check_disk_change(bdev);
6919  out:
6920         return err;
6921 }
6922 
6923 static void md_release(struct gendisk *disk, fmode_t mode)
6924 {
6925         struct mddev *mddev = disk->private_data;
6926 
6927         BUG_ON(!mddev);
6928         atomic_dec(&mddev->openers);
6929         mddev_put(mddev);
6930 }
6931 
6932 static int md_media_changed(struct gendisk *disk)
6933 {
6934         struct mddev *mddev = disk->private_data;
6935 
6936         return mddev->changed;
6937 }
6938 
6939 static int md_revalidate(struct gendisk *disk)
6940 {
6941         struct mddev *mddev = disk->private_data;
6942 
6943         mddev->changed = 0;
6944         return 0;
6945 }
6946 static const struct block_device_operations md_fops =
6947 {
6948         .owner          = THIS_MODULE,
6949         .open           = md_open,
6950         .release        = md_release,
6951         .ioctl          = md_ioctl,
6952 #ifdef CONFIG_COMPAT
6953         .compat_ioctl   = md_compat_ioctl,
6954 #endif
6955         .getgeo         = md_getgeo,
6956         .media_changed  = md_media_changed,
6957         .revalidate_disk= md_revalidate,
6958 };
6959 
6960 static int md_thread(void *arg)
6961 {
6962         struct md_thread *thread = arg;
6963 
6964         /*
6965          * md_thread is a 'system-thread', it's priority should be very
6966          * high. We avoid resource deadlocks individually in each
6967          * raid personality. (RAID5 does preallocation) We also use RR and
6968          * the very same RT priority as kswapd, thus we will never get
6969          * into a priority inversion deadlock.
6970          *
6971          * we definitely have to have equal or higher priority than
6972          * bdflush, otherwise bdflush will deadlock if there are too
6973          * many dirty RAID5 blocks.
6974          */
6975 
6976         allow_signal(SIGKILL);
6977         while (!kthread_should_stop()) {
6978 
6979                 /* We need to wait INTERRUPTIBLE so that
6980                  * we don't add to the load-average.
6981                  * That means we need to be sure no signals are
6982                  * pending
6983                  */
6984                 if (signal_pending(current))
6985                         flush_signals(current);
6986 
6987                 wait_event_interruptible_timeout
6988                         (thread->wqueue,
6989                          test_bit(THREAD_WAKEUP, &thread->flags)
6990                          || kthread_should_stop(),
6991                          thread->timeout);
6992 
6993                 clear_bit(THREAD_WAKEUP, &thread->flags);
6994                 if (!kthread_should_stop())
6995                         thread->run(thread);
6996         }
6997 
6998         return 0;
6999 }
7000 
7001 void md_wakeup_thread(struct md_thread *thread)
7002 {
7003         if (thread) {
7004                 pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
7005                 set_bit(THREAD_WAKEUP, &thread->flags);
7006                 wake_up(&thread->wqueue);
7007         }
7008 }
7009 EXPORT_SYMBOL(md_wakeup_thread);
7010 
7011 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
7012                 struct mddev *mddev, const char *name)
7013 {
7014         struct md_thread *thread;
7015 
7016         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
7017         if (!thread)
7018                 return NULL;
7019 
7020         init_waitqueue_head(&thread->wqueue);
7021 
7022         thread->run = run;
7023         thread->mddev = mddev;
7024         thread->timeout = MAX_SCHEDULE_TIMEOUT;
7025         thread->tsk = kthread_run(md_thread, thread,
7026                                   "%s_%s",
7027                                   mdname(thread->mddev),
7028                                   name);
7029         if (IS_ERR(thread->tsk)) {
7030                 kfree(thread);
7031                 return NULL;
7032         }
7033         return thread;
7034 }
7035 EXPORT_SYMBOL(md_register_thread);
7036 
7037 void md_unregister_thread(struct md_thread **threadp)
7038 {
7039         struct md_thread *thread = *threadp;
7040         if (!thread)
7041                 return;
7042         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
7043         /* Locking ensures that mddev_unlock does not wake_up a
7044          * non-existent thread
7045          */
7046         spin_lock(&pers_lock);
7047         *threadp = NULL;
7048         spin_unlock(&pers_lock);
7049 
7050         kthread_stop(thread->tsk);
7051         kfree(thread);
7052 }
7053 EXPORT_SYMBOL(md_unregister_thread);
7054 
7055 void md_error(struct mddev *mddev, struct md_rdev *rdev)
7056 {
7057         if (!rdev || test_bit(Faulty, &rdev->flags))
7058                 return;
7059 
7060         if (!mddev->pers || !mddev->pers->error_handler)
7061                 return;
7062         mddev->pers->error_handler(mddev,rdev);
7063         if (mddev->degraded)
7064                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7065         sysfs_notify_dirent_safe(rdev->sysfs_state);
7066         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7067         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7068         md_wakeup_thread(mddev->thread);
7069         if (mddev->event_work.func)
7070                 queue_work(md_misc_wq, &mddev->event_work);
7071         md_new_event_inintr(mddev);
7072 }
7073 EXPORT_SYMBOL(md_error);
7074 
7075 /* seq_file implementation /proc/mdstat */
7076 
7077 static void status_unused(struct seq_file *seq)
7078 {
7079         int i = 0;
7080         struct md_rdev *rdev;
7081 
7082         seq_printf(seq, "unused devices: ");
7083 
7084         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
7085                 char b[BDEVNAME_SIZE];
7086                 i++;
7087                 seq_printf(seq, "%s ",
7088                               bdevname(rdev->bdev,b));
7089         }
7090         if (!i)
7091                 seq_printf(seq, "<none>");
7092 
7093         seq_printf(seq, "\n");
7094 }
7095 
7096 static void status_resync(struct seq_file *seq, struct mddev *mddev)
7097 {
7098         sector_t max_sectors, resync, res;
7099         unsigned long dt, db;
7100         sector_t rt;
7101         int scale;
7102         unsigned int per_milli;
7103 
7104         if (mddev->curr_resync <= 3)
7105                 resync = 0;
7106         else
7107                 resync = mddev->curr_resync
7108                         - atomic_read(&mddev->recovery_active);
7109 
7110         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
7111             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7112                 max_sectors = mddev->resync_max_sectors;
7113         else
7114                 max_sectors = mddev->dev_sectors;
7115 
7116         WARN_ON(max_sectors == 0);
7117         /* Pick 'scale' such that (resync>>scale)*1000 will fit
7118          * in a sector_t, and (max_sectors>>scale) will fit in a
7119          * u32, as those are the requirements for sector_div.
7120          * Thus 'scale' must be at least 10
7121          */
7122         scale = 10;
7123         if (sizeof(sector_t) > sizeof(unsigned long)) {
7124                 while ( max_sectors/2 > (1ULL<<(scale+32)))
7125                         scale++;
7126         }
7127         res = (resync>>scale)*1000;
7128         sector_div(res, (u32)((max_sectors>>scale)+1));
7129 
7130         per_milli = res;
7131         {
7132                 int i, x = per_milli/50, y = 20-x;
7133                 seq_printf(seq, "[");
7134                 for (i = 0; i < x; i++)
7135                         seq_printf(seq, "=");
7136                 seq_printf(seq, ">");
7137                 for (i = 0; i < y; i++)
7138                         seq_printf(seq, ".");
7139                 seq_printf(seq, "] ");
7140         }
7141         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
7142                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
7143                     "reshape" :
7144                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
7145                      "check" :
7146                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
7147                       "resync" : "recovery"))),
7148                    per_milli/10, per_milli % 10,
7149                    (unsigned long long) resync/2,
7150                    (unsigned long long) max_sectors/2);
7151 
7152         /*
7153          * dt: time from mark until now
7154          * db: blocks written from mark until now
7155          * rt: remaining time
7156          *
7157          * rt is a sector_t, so could be 32bit or 64bit.
7158          * So we divide before multiply in case it is 32bit and close
7159          * to the limit.
7160          * We scale the divisor (db) by 32 to avoid losing precision
7161          * near the end of resync when the number of remaining sectors
7162          * is close to 'db'.
7163          * We then divide rt by 32 after multiplying by db to compensate.
7164          * The '+1' avoids division by zero if db is very small.
7165          */
7166         dt = ((jiffies - mddev->resync_mark) / HZ);
7167         if (!dt) dt++;
7168         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
7169                 - mddev->resync_mark_cnt;
7170 
7171         rt = max_sectors - resync;    /* number of remaining sectors */
7172         sector_div(rt, db/32+1);
7173         rt *= dt;
7174         rt >>= 5;
7175 
7176         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
7177                    ((unsigned long)rt % 60)/6);
7178 
7179         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
7180 }
7181 
7182 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
7183 {
7184         struct list_head *tmp;
7185         loff_t l = *pos;
7186         struct mddev *mddev;
7187 
7188         if (l >= 0x10000)
7189                 return NULL;
7190         if (!l--)
7191                 /* header */
7192                 return (void*)1;
7193 
7194         spin_lock(&all_mddevs_lock);
7195         list_for_each(tmp,&all_mddevs)
7196                 if (!l--) {
7197                         mddev = list_entry(tmp, struct mddev, all_mddevs);
7198                         mddev_get(mddev);
7199                         spin_unlock(&all_mddevs_lock);
7200                         return mddev;
7201                 }
7202         spin_unlock(&all_mddevs_lock);
7203         if (!l--)
7204                 return (void*)2;/* tail */
7205         return NULL;
7206 }
7207 
7208 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
7209 {
7210         struct list_head *tmp;
7211         struct mddev *next_mddev, *mddev = v;
7212 
7213         ++*pos;
7214         if (v == (void*)2)
7215                 return NULL;
7216 
7217         spin_lock(&all_mddevs_lock);
7218         if (v == (void*)1)
7219                 tmp = all_mddevs.next;
7220         else
7221                 tmp = mddev->all_mddevs.next;
7222         if (tmp != &all_mddevs)
7223                 next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
7224         else {
7225                 next_mddev = (void*)2;
7226                 *pos = 0x10000;
7227         }
7228         spin_unlock(&all_mddevs_lock);
7229 
7230         if (v != (void*)1)
7231                 mddev_put(mddev);
7232         return next_mddev;
7233 
7234 }
7235 
7236 static void md_seq_stop(struct seq_file *seq, void *v)
7237 {
7238         struct mddev *mddev = v;
7239 
7240         if (mddev && v != (void*)1 && v != (void*)2)
7241                 mddev_put(mddev);
7242 }
7243 
7244 static int md_seq_show(struct seq_file *seq, void *v)
7245 {
7246         struct mddev *mddev = v;
7247         sector_t sectors;
7248         struct md_rdev *rdev;
7249 
7250         if (v == (void*)1) {
7251                 struct md_personality *pers;
7252                 seq_printf(seq, "Personalities : ");
7253                 spin_lock(&pers_lock);
7254                 list_for_each_entry(pers, &pers_list, list)
7255                         seq_printf(seq, "[%s] ", pers->name);
7256 
7257                 spin_unlock(&pers_lock);
7258                 seq_printf(seq, "\n");
7259                 seq->poll_event = atomic_read(&md_event_count);
7260                 return 0;
7261         }
7262         if (v == (void*)2) {
7263                 status_unused(seq);
7264                 return 0;
7265         }
7266 
7267         spin_lock(&mddev->lock);
7268         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
7269                 seq_printf(seq, "%s : %sactive", mdname(mddev),
7270                                                 mddev->pers ? "" : "in");
7271                 if (mddev->pers) {
7272                         if (mddev->ro==1)
7273                                 seq_printf(seq, " (read-only)");
7274                         if (mddev->ro==2)
7275                                 seq_printf(seq, " (auto-read-only)");
7276                         seq_printf(seq, " %s", mddev->pers->name);
7277                 }
7278 
7279                 sectors = 0;
7280                 rcu_read_lock();
7281                 rdev_for_each_rcu(rdev, mddev) {
7282                         char b[BDEVNAME_SIZE];
7283                         seq_printf(seq, " %s[%d]",
7284                                 bdevname(rdev->bdev,b), rdev->desc_nr);
7285                         if (test_bit(WriteMostly, &rdev->flags))
7286                                 seq_printf(seq, "(W)");
7287                         if (test_bit(Faulty, &rdev->flags)) {
7288                                 seq_printf(seq, "(F)");
7289                                 continue;
7290                         }
7291                         if (rdev->raid_disk < 0)
7292                                 seq_printf(seq, "(S)"); /* spare */
7293                         if (test_bit(Replacement, &rdev->flags))
7294                                 seq_printf(seq, "(R)");
7295                         sectors += rdev->sectors;
7296                 }
7297                 rcu_read_unlock();
7298 
7299                 if (!list_empty(&mddev->disks)) {
7300                         if (mddev->pers)
7301                                 seq_printf(seq, "\n      %llu blocks",
7302                                            (unsigned long long)
7303                                            mddev->array_sectors / 2);
7304                         else
7305                                 seq_printf(seq, "\n      %llu blocks",
7306                                            (unsigned long long)sectors / 2);
7307                 }
7308                 if (mddev->persistent) {
7309                         if (mddev->major_version != 0 ||
7310                             mddev->minor_version != 90) {
7311                                 seq_printf(seq," super %d.%d",
7312                                            mddev->major_version,
7313                                            mddev->minor_version);
7314                         }
7315                 } else if (mddev->external)
7316                         seq_printf(seq, " super external:%s",
7317                                    mddev->metadata_type);
7318                 else
7319                         seq_printf(seq, " super non-persistent");
7320 
7321                 if (mddev->pers) {
7322                         mddev->pers->status(seq, mddev);
7323                         seq_printf(seq, "\n      ");
7324                         if (mddev->pers->sync_request) {
7325                                 if (mddev->curr_resync > 2) {
7326                                         status_resync(seq, mddev);
7327                                         seq_printf(seq, "\n      ");
7328                                 } else if (mddev->curr_resync >= 1)
7329                                         seq_printf(seq, "\tresync=DELAYED\n      ");
7330                                 else if (mddev->recovery_cp < MaxSector)
7331                                         seq_printf(seq, "\tresync=PENDING\n      ");
7332                         }
7333                 } else
7334                         seq_printf(seq, "\n       ");
7335 
7336                 bitmap_status(seq, mddev->bitmap);
7337 
7338                 seq_printf(seq, "\n");
7339         }
7340         spin_unlock(&mddev->lock);
7341 
7342         return 0;
7343 }
7344 
7345 static const struct seq_operations md_seq_ops = {
7346         .start  = md_seq_start,
7347         .next   = md_seq_next,
7348         .stop   = md_seq_stop,
7349         .show   = md_seq_show,
7350 };
7351 
7352 static int md_seq_open(struct inode *inode, struct file *file)
7353 {
7354         struct seq_file *seq;
7355         int error;
7356 
7357         error = seq_open(file, &md_seq_ops);
7358         if (error)
7359                 return error;
7360 
7361         seq = file->private_data;
7362         seq->poll_event = atomic_read(&md_event_count);
7363         return error;
7364 }
7365 
7366 static int md_unloading;
7367 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7368 {
7369         struct seq_file *seq = filp->private_data;
7370         int mask;
7371 
7372         if (md_unloading)
7373                 return POLLIN|POLLRDNORM|POLLERR|POLLPRI;
7374         poll_wait(filp, &md_event_waiters, wait);
7375 
7376         /* always allow read */
7377         mask = POLLIN | POLLRDNORM;
7378 
7379         if (seq->poll_event != atomic_read(&md_event_count))
7380                 mask |= POLLERR | POLLPRI;
7381         return mask;
7382 }
7383 
7384 static const struct file_operations md_seq_fops = {
7385         .owner          = THIS_MODULE,
7386         .open           = md_seq_open,
7387         .read           = seq_read,
7388         .llseek         = seq_lseek,
7389         .release        = seq_release_private,
7390         .poll           = mdstat_poll,
7391 };
7392 
7393 int register_md_personality(struct md_personality *p)
7394 {
7395         printk(KERN_INFO "md: %s personality registered for level %d\n",
7396                                                 p->name, p->level);
7397         spin_lock(&pers_lock);
7398         list_add_tail(&p->list, &pers_list);
7399         spin_unlock(&pers_lock);
7400         return 0;
7401 }
7402 EXPORT_SYMBOL(register_md_personality);
7403 
7404 int unregister_md_personality(struct md_personality *p)
7405 {
7406         printk(KERN_INFO "md: %s personality unregistered\n", p->name);
7407         spin_lock(&pers_lock);
7408         list_del_init(&p->list);
7409         spin_unlock(&pers_lock);
7410         return 0;
7411 }
7412 EXPORT_SYMBOL(unregister_md_personality);
7413 
7414 int register_md_cluster_operations(struct md_cluster_operations *ops, struct module *module)
7415 {
7416         if (md_cluster_ops != NULL)
7417                 return -EALREADY;
7418         spin_lock(&pers_lock);
7419         md_cluster_ops = ops;
7420         md_cluster_mod = module;
7421         spin_unlock(&pers_lock);
7422         return 0;
7423 }
7424 EXPORT_SYMBOL(register_md_cluster_operations);
7425 
7426 int unregister_md_cluster_operations(void)
7427 {
7428         spin_lock(&pers_lock);
7429         md_cluster_ops = NULL;
7430         spin_unlock(&pers_lock);
7431         return 0;
7432 }
7433 EXPORT_SYMBOL(unregister_md_cluster_operations);
7434 
7435 int md_setup_cluster(struct mddev *mddev, int nodes)
7436 {
7437         int err;
7438 
7439         err = request_module("md-cluster");
7440         if (err) {
7441                 pr_err("md-cluster module not found.\n");
7442                 return -ENOENT;
7443         }
7444 
7445         spin_lock(&pers_lock);
7446         if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
7447                 spin_unlock(&pers_lock);
7448                 return -ENOENT;
7449         }
7450         spin_unlock(&pers_lock);
7451 
7452         return md_cluster_ops->join(mddev, nodes);
7453 }
7454 
7455 void md_cluster_stop(struct mddev *mddev)
7456 {
7457         if (!md_cluster_ops)
7458                 return;
7459         md_cluster_ops->leave(mddev);
7460         module_put(md_cluster_mod);
7461 }
7462 
7463 static int is_mddev_idle(struct mddev *mddev, int init)
7464 {
7465         struct md_rdev *rdev;
7466         int idle;
7467         int curr_events;
7468 
7469         idle = 1;
7470         rcu_read_lock();
7471         rdev_for_each_rcu(rdev, mddev) {
7472                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
7473                 curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
7474                               (int)part_stat_read(&disk->part0, sectors[1]) -
7475                               atomic_read(&disk->sync_io);
7476                 /* sync IO will cause sync_io to increase before the disk_stats
7477                  * as sync_io is counted when a request starts, and
7478                  * disk_stats is counted when it completes.
7479                  * So resync activity will cause curr_events to be smaller than
7480                  * when there was no such activity.
7481                  * non-sync IO will cause disk_stat to increase without
7482                  * increasing sync_io so curr_events will (eventually)
7483                  * be larger than it was before.  Once it becomes
7484                  * substantially larger, the test below will cause
7485                  * the array to appear non-idle, and resync will slow
7486                  * down.
7487                  * If there is a lot of outstanding resync activity when
7488                  * we set last_event to curr_events, then all that activity
7489                  * completing might cause the array to appear non-idle
7490                  * and resync will be slowed down even though there might
7491                  * not have been non-resync activity.  This will only
7492                  * happen once though.  'last_events' will soon reflect
7493                  * the state where there is little or no outstanding
7494                  * resync requests, and further resync activity will
7495                  * always make curr_events less than last_events.
7496                  *
7497                  */
7498                 if (init || curr_events - rdev->last_events > 64) {
7499                         rdev->last_events = curr_events;
7500                         idle = 0;
7501                 }
7502         }
7503         rcu_read_unlock();
7504         return idle;
7505 }
7506 
7507 void md_done_sync(struct mddev *mddev, int blocks, int ok)
7508 {
7509         /* another "blocks" (512byte) blocks have been synced */
7510         atomic_sub(blocks, &mddev->recovery_active);
7511         wake_up(&mddev->recovery_wait);
7512         if (!ok) {
7513                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7514                 set_bit(MD_RECOVERY_ERROR, &mddev->recovery);
7515                 md_wakeup_thread(mddev->thread);
7516                 // stop recovery, signal do_sync ....
7517         }
7518 }
7519 EXPORT_SYMBOL(md_done_sync);
7520 
7521 /* md_write_start(mddev, bi)
7522  * If we need to update some array metadata (e.g. 'active' flag
7523  * in superblock) before writing, schedule a superblock update
7524  * and wait for it to complete.
7525  */
7526 void md_write_start(struct mddev *mddev, struct bio *bi)
7527 {
7528         int did_change = 0;
7529         if (bio_data_dir(bi) != WRITE)
7530                 return;
7531 
7532         BUG_ON(mddev->ro == 1);
7533         if (