Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

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 
 57 #ifndef MODULE
 58 static void autostart_arrays(int part);
 59 #endif
 60 
 61 /* pers_list is a list of registered personalities protected
 62  * by pers_lock.
 63  * pers_lock does extra service to protect accesses to
 64  * mddev->thread when the mutex cannot be held.
 65  */
 66 static LIST_HEAD(pers_list);
 67 static DEFINE_SPINLOCK(pers_lock);
 68 
 69 static void md_print_devices(void);
 70 
 71 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 72 static struct workqueue_struct *md_wq;
 73 static struct workqueue_struct *md_misc_wq;
 74 
 75 static int remove_and_add_spares(struct mddev *mddev,
 76                                  struct md_rdev *this);
 77 
 78 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 79 
 80 /*
 81  * Default number of read corrections we'll attempt on an rdev
 82  * before ejecting it from the array. We divide the read error
 83  * count by 2 for every hour elapsed between read errors.
 84  */
 85 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
 86 /*
 87  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 88  * is 1000 KB/sec, so the extra system load does not show up that much.
 89  * Increase it if you want to have more _guaranteed_ speed. Note that
 90  * the RAID driver will use the maximum available bandwidth if the IO
 91  * subsystem is idle. There is also an 'absolute maximum' reconstruction
 92  * speed limit - in case reconstruction slows down your system despite
 93  * idle IO detection.
 94  *
 95  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
 96  * or /sys/block/mdX/md/sync_speed_{min,max}
 97  */
 98 
 99 static int sysctl_speed_limit_min = 1000;
100 static int sysctl_speed_limit_max = 200000;
101 static inline int speed_min(struct mddev *mddev)
102 {
103         return mddev->sync_speed_min ?
104                 mddev->sync_speed_min : sysctl_speed_limit_min;
105 }
106 
107 static inline int speed_max(struct mddev *mddev)
108 {
109         return mddev->sync_speed_max ?
110                 mddev->sync_speed_max : sysctl_speed_limit_max;
111 }
112 
113 static struct ctl_table_header *raid_table_header;
114 
115 static struct ctl_table raid_table[] = {
116         {
117                 .procname       = "speed_limit_min",
118                 .data           = &sysctl_speed_limit_min,
119                 .maxlen         = sizeof(int),
120                 .mode           = S_IRUGO|S_IWUSR,
121                 .proc_handler   = proc_dointvec,
122         },
123         {
124                 .procname       = "speed_limit_max",
125                 .data           = &sysctl_speed_limit_max,
126                 .maxlen         = sizeof(int),
127                 .mode           = S_IRUGO|S_IWUSR,
128                 .proc_handler   = proc_dointvec,
129         },
130         { }
131 };
132 
133 static struct ctl_table raid_dir_table[] = {
134         {
135                 .procname       = "raid",
136                 .maxlen         = 0,
137                 .mode           = S_IRUGO|S_IXUGO,
138                 .child          = raid_table,
139         },
140         { }
141 };
142 
143 static struct ctl_table raid_root_table[] = {
144         {
145                 .procname       = "dev",
146                 .maxlen         = 0,
147                 .mode           = 0555,
148                 .child          = raid_dir_table,
149         },
150         {  }
151 };
152 
153 static const struct block_device_operations md_fops;
154 
155 static int start_readonly;
156 
157 /* bio_clone_mddev
158  * like bio_clone, but with a local bio set
159  */
160 
161 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
162                             struct mddev *mddev)
163 {
164         struct bio *b;
165 
166         if (!mddev || !mddev->bio_set)
167                 return bio_alloc(gfp_mask, nr_iovecs);
168 
169         b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
170         if (!b)
171                 return NULL;
172         return b;
173 }
174 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
175 
176 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
177                             struct mddev *mddev)
178 {
179         if (!mddev || !mddev->bio_set)
180                 return bio_clone(bio, gfp_mask);
181 
182         return bio_clone_bioset(bio, gfp_mask, mddev->bio_set);
183 }
184 EXPORT_SYMBOL_GPL(bio_clone_mddev);
185 
186 /*
187  * We have a system wide 'event count' that is incremented
188  * on any 'interesting' event, and readers of /proc/mdstat
189  * can use 'poll' or 'select' to find out when the event
190  * count increases.
191  *
192  * Events are:
193  *  start array, stop array, error, add device, remove device,
194  *  start build, activate spare
195  */
196 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
197 static atomic_t md_event_count;
198 void md_new_event(struct mddev *mddev)
199 {
200         atomic_inc(&md_event_count);
201         wake_up(&md_event_waiters);
202 }
203 EXPORT_SYMBOL_GPL(md_new_event);
204 
205 /* Alternate version that can be called from interrupts
206  * when calling sysfs_notify isn't needed.
207  */
208 static void md_new_event_inintr(struct mddev *mddev)
209 {
210         atomic_inc(&md_event_count);
211         wake_up(&md_event_waiters);
212 }
213 
214 /*
215  * Enables to iterate over all existing md arrays
216  * all_mddevs_lock protects this list.
217  */
218 static LIST_HEAD(all_mddevs);
219 static DEFINE_SPINLOCK(all_mddevs_lock);
220 
221 
222 /*
223  * iterates through all used mddevs in the system.
224  * We take care to grab the all_mddevs_lock whenever navigating
225  * the list, and to always hold a refcount when unlocked.
226  * Any code which breaks out of this loop while own
227  * a reference to the current mddev and must mddev_put it.
228  */
229 #define for_each_mddev(_mddev,_tmp)                                     \
230                                                                         \
231         for (({ spin_lock(&all_mddevs_lock);                            \
232                 _tmp = all_mddevs.next;                                 \
233                 _mddev = NULL;});                                       \
234              ({ if (_tmp != &all_mddevs)                                \
235                         mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
236                 spin_unlock(&all_mddevs_lock);                          \
237                 if (_mddev) mddev_put(_mddev);                          \
238                 _mddev = list_entry(_tmp, struct mddev, all_mddevs);    \
239                 _tmp != &all_mddevs;});                                 \
240              ({ spin_lock(&all_mddevs_lock);                            \
241                 _tmp = _tmp->next;})                                    \
242                 )
243 
244 
245 /* Rather than calling directly into the personality make_request function,
246  * IO requests come here first so that we can check if the device is
247  * being suspended pending a reconfiguration.
248  * We hold a refcount over the call to ->make_request.  By the time that
249  * call has finished, the bio has been linked into some internal structure
250  * and so is visible to ->quiesce(), so we don't need the refcount any more.
251  */
252 static void md_make_request(struct request_queue *q, struct bio *bio)
253 {
254         const int rw = bio_data_dir(bio);
255         struct mddev *mddev = q->queuedata;
256         int cpu;
257         unsigned int sectors;
258 
259         if (mddev == NULL || mddev->pers == NULL
260             || !mddev->ready) {
261                 bio_io_error(bio);
262                 return;
263         }
264         if (mddev->ro == 1 && unlikely(rw == WRITE)) {
265                 bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
266                 return;
267         }
268         smp_rmb(); /* Ensure implications of  'active' are visible */
269         rcu_read_lock();
270         if (mddev->suspended) {
271                 DEFINE_WAIT(__wait);
272                 for (;;) {
273                         prepare_to_wait(&mddev->sb_wait, &__wait,
274                                         TASK_UNINTERRUPTIBLE);
275                         if (!mddev->suspended)
276                                 break;
277                         rcu_read_unlock();
278                         schedule();
279                         rcu_read_lock();
280                 }
281                 finish_wait(&mddev->sb_wait, &__wait);
282         }
283         atomic_inc(&mddev->active_io);
284         rcu_read_unlock();
285 
286         /*
287          * save the sectors now since our bio can
288          * go away inside make_request
289          */
290         sectors = bio_sectors(bio);
291         mddev->pers->make_request(mddev, bio);
292 
293         cpu = part_stat_lock();
294         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
295         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
296         part_stat_unlock();
297 
298         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
299                 wake_up(&mddev->sb_wait);
300 }
301 
302 /* mddev_suspend makes sure no new requests are submitted
303  * to the device, and that any requests that have been submitted
304  * are completely handled.
305  * Once ->stop is called and completes, the module will be completely
306  * unused.
307  */
308 void mddev_suspend(struct mddev *mddev)
309 {
310         BUG_ON(mddev->suspended);
311         mddev->suspended = 1;
312         synchronize_rcu();
313         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
314         mddev->pers->quiesce(mddev, 1);
315 
316         del_timer_sync(&mddev->safemode_timer);
317 }
318 EXPORT_SYMBOL_GPL(mddev_suspend);
319 
320 void mddev_resume(struct mddev *mddev)
321 {
322         mddev->suspended = 0;
323         wake_up(&mddev->sb_wait);
324         mddev->pers->quiesce(mddev, 0);
325 
326         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
327         md_wakeup_thread(mddev->thread);
328         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
329 }
330 EXPORT_SYMBOL_GPL(mddev_resume);
331 
332 int mddev_congested(struct mddev *mddev, int bits)
333 {
334         return mddev->suspended;
335 }
336 EXPORT_SYMBOL(mddev_congested);
337 
338 /*
339  * Generic flush handling for md
340  */
341 
342 static void md_end_flush(struct bio *bio, int err)
343 {
344         struct md_rdev *rdev = bio->bi_private;
345         struct mddev *mddev = rdev->mddev;
346 
347         rdev_dec_pending(rdev, mddev);
348 
349         if (atomic_dec_and_test(&mddev->flush_pending)) {
350                 /* The pre-request flush has finished */
351                 queue_work(md_wq, &mddev->flush_work);
352         }
353         bio_put(bio);
354 }
355 
356 static void md_submit_flush_data(struct work_struct *ws);
357 
358 static void submit_flushes(struct work_struct *ws)
359 {
360         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
361         struct md_rdev *rdev;
362 
363         INIT_WORK(&mddev->flush_work, md_submit_flush_data);
364         atomic_set(&mddev->flush_pending, 1);
365         rcu_read_lock();
366         rdev_for_each_rcu(rdev, mddev)
367                 if (rdev->raid_disk >= 0 &&
368                     !test_bit(Faulty, &rdev->flags)) {
369                         /* Take two references, one is dropped
370                          * when request finishes, one after
371                          * we reclaim rcu_read_lock
372                          */
373                         struct bio *bi;
374                         atomic_inc(&rdev->nr_pending);
375                         atomic_inc(&rdev->nr_pending);
376                         rcu_read_unlock();
377                         bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
378                         bi->bi_end_io = md_end_flush;
379                         bi->bi_private = rdev;
380                         bi->bi_bdev = rdev->bdev;
381                         atomic_inc(&mddev->flush_pending);
382                         submit_bio(WRITE_FLUSH, bi);
383                         rcu_read_lock();
384                         rdev_dec_pending(rdev, mddev);
385                 }
386         rcu_read_unlock();
387         if (atomic_dec_and_test(&mddev->flush_pending))
388                 queue_work(md_wq, &mddev->flush_work);
389 }
390 
391 static void md_submit_flush_data(struct work_struct *ws)
392 {
393         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
394         struct bio *bio = mddev->flush_bio;
395 
396         if (bio->bi_iter.bi_size == 0)
397                 /* an empty barrier - all done */
398                 bio_endio(bio, 0);
399         else {
400                 bio->bi_rw &= ~REQ_FLUSH;
401                 mddev->pers->make_request(mddev, bio);
402         }
403 
404         mddev->flush_bio = NULL;
405         wake_up(&mddev->sb_wait);
406 }
407 
408 void md_flush_request(struct mddev *mddev, struct bio *bio)
409 {
410         spin_lock_irq(&mddev->write_lock);
411         wait_event_lock_irq(mddev->sb_wait,
412                             !mddev->flush_bio,
413                             mddev->write_lock);
414         mddev->flush_bio = bio;
415         spin_unlock_irq(&mddev->write_lock);
416 
417         INIT_WORK(&mddev->flush_work, submit_flushes);
418         queue_work(md_wq, &mddev->flush_work);
419 }
420 EXPORT_SYMBOL(md_flush_request);
421 
422 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
423 {
424         struct mddev *mddev = cb->data;
425         md_wakeup_thread(mddev->thread);
426         kfree(cb);
427 }
428 EXPORT_SYMBOL(md_unplug);
429 
430 static inline struct mddev *mddev_get(struct mddev *mddev)
431 {
432         atomic_inc(&mddev->active);
433         return mddev;
434 }
435 
436 static void mddev_delayed_delete(struct work_struct *ws);
437 
438 static void mddev_put(struct mddev *mddev)
439 {
440         struct bio_set *bs = NULL;
441 
442         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
443                 return;
444         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
445             mddev->ctime == 0 && !mddev->hold_active) {
446                 /* Array is not configured at all, and not held active,
447                  * so destroy it */
448                 list_del_init(&mddev->all_mddevs);
449                 bs = mddev->bio_set;
450                 mddev->bio_set = NULL;
451                 if (mddev->gendisk) {
452                         /* We did a probe so need to clean up.  Call
453                          * queue_work inside the spinlock so that
454                          * flush_workqueue() after mddev_find will
455                          * succeed in waiting for the work to be done.
456                          */
457                         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
458                         queue_work(md_misc_wq, &mddev->del_work);
459                 } else
460                         kfree(mddev);
461         }
462         spin_unlock(&all_mddevs_lock);
463         if (bs)
464                 bioset_free(bs);
465 }
466 
467 void mddev_init(struct mddev *mddev)
468 {
469         mutex_init(&mddev->open_mutex);
470         mutex_init(&mddev->reconfig_mutex);
471         mutex_init(&mddev->bitmap_info.mutex);
472         INIT_LIST_HEAD(&mddev->disks);
473         INIT_LIST_HEAD(&mddev->all_mddevs);
474         init_timer(&mddev->safemode_timer);
475         atomic_set(&mddev->active, 1);
476         atomic_set(&mddev->openers, 0);
477         atomic_set(&mddev->active_io, 0);
478         spin_lock_init(&mddev->write_lock);
479         atomic_set(&mddev->flush_pending, 0);
480         init_waitqueue_head(&mddev->sb_wait);
481         init_waitqueue_head(&mddev->recovery_wait);
482         mddev->reshape_position = MaxSector;
483         mddev->reshape_backwards = 0;
484         mddev->last_sync_action = "none";
485         mddev->resync_min = 0;
486         mddev->resync_max = MaxSector;
487         mddev->level = LEVEL_NONE;
488 }
489 EXPORT_SYMBOL_GPL(mddev_init);
490 
491 static struct mddev * mddev_find(dev_t unit)
492 {
493         struct mddev *mddev, *new = NULL;
494 
495         if (unit && MAJOR(unit) != MD_MAJOR)
496                 unit &= ~((1<<MdpMinorShift)-1);
497 
498  retry:
499         spin_lock(&all_mddevs_lock);
500 
501         if (unit) {
502                 list_for_each_entry(mddev, &all_mddevs, all_mddevs)
503                         if (mddev->unit == unit) {
504                                 mddev_get(mddev);
505                                 spin_unlock(&all_mddevs_lock);
506                                 kfree(new);
507                                 return mddev;
508                         }
509 
510                 if (new) {
511                         list_add(&new->all_mddevs, &all_mddevs);
512                         spin_unlock(&all_mddevs_lock);
513                         new->hold_active = UNTIL_IOCTL;
514                         return new;
515                 }
516         } else if (new) {
517                 /* find an unused unit number */
518                 static int next_minor = 512;
519                 int start = next_minor;
520                 int is_free = 0;
521                 int dev = 0;
522                 while (!is_free) {
523                         dev = MKDEV(MD_MAJOR, next_minor);
524                         next_minor++;
525                         if (next_minor > MINORMASK)
526                                 next_minor = 0;
527                         if (next_minor == start) {
528                                 /* Oh dear, all in use. */
529                                 spin_unlock(&all_mddevs_lock);
530                                 kfree(new);
531                                 return NULL;
532                         }
533                                 
534                         is_free = 1;
535                         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
536                                 if (mddev->unit == dev) {
537                                         is_free = 0;
538                                         break;
539                                 }
540                 }
541                 new->unit = dev;
542                 new->md_minor = MINOR(dev);
543                 new->hold_active = UNTIL_STOP;
544                 list_add(&new->all_mddevs, &all_mddevs);
545                 spin_unlock(&all_mddevs_lock);
546                 return new;
547         }
548         spin_unlock(&all_mddevs_lock);
549 
550         new = kzalloc(sizeof(*new), GFP_KERNEL);
551         if (!new)
552                 return NULL;
553 
554         new->unit = unit;
555         if (MAJOR(unit) == MD_MAJOR)
556                 new->md_minor = MINOR(unit);
557         else
558                 new->md_minor = MINOR(unit) >> MdpMinorShift;
559 
560         mddev_init(new);
561 
562         goto retry;
563 }
564 
565 static inline int __must_check mddev_lock(struct mddev * mddev)
566 {
567         return mutex_lock_interruptible(&mddev->reconfig_mutex);
568 }
569 
570 /* Sometimes we need to take the lock in a situation where
571  * failure due to interrupts is not acceptable.
572  */
573 static inline void mddev_lock_nointr(struct mddev * mddev)
574 {
575         mutex_lock(&mddev->reconfig_mutex);
576 }
577 
578 static inline int mddev_is_locked(struct mddev *mddev)
579 {
580         return mutex_is_locked(&mddev->reconfig_mutex);
581 }
582 
583 static inline int mddev_trylock(struct mddev * mddev)
584 {
585         return mutex_trylock(&mddev->reconfig_mutex);
586 }
587 
588 static struct attribute_group md_redundancy_group;
589 
590 static void mddev_unlock(struct mddev * mddev)
591 {
592         if (mddev->to_remove) {
593                 /* These cannot be removed under reconfig_mutex as
594                  * an access to the files will try to take reconfig_mutex
595                  * while holding the file unremovable, which leads to
596                  * a deadlock.
597                  * So hold set sysfs_active while the remove in happeing,
598                  * and anything else which might set ->to_remove or my
599                  * otherwise change the sysfs namespace will fail with
600                  * -EBUSY if sysfs_active is still set.
601                  * We set sysfs_active under reconfig_mutex and elsewhere
602                  * test it under the same mutex to ensure its correct value
603                  * is seen.
604                  */
605                 struct attribute_group *to_remove = mddev->to_remove;
606                 mddev->to_remove = NULL;
607                 mddev->sysfs_active = 1;
608                 mutex_unlock(&mddev->reconfig_mutex);
609 
610                 if (mddev->kobj.sd) {
611                         if (to_remove != &md_redundancy_group)
612                                 sysfs_remove_group(&mddev->kobj, to_remove);
613                         if (mddev->pers == NULL ||
614                             mddev->pers->sync_request == NULL) {
615                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
616                                 if (mddev->sysfs_action)
617                                         sysfs_put(mddev->sysfs_action);
618                                 mddev->sysfs_action = NULL;
619                         }
620                 }
621                 mddev->sysfs_active = 0;
622         } else
623                 mutex_unlock(&mddev->reconfig_mutex);
624 
625         /* As we've dropped the mutex we need a spinlock to
626          * make sure the thread doesn't disappear
627          */
628         spin_lock(&pers_lock);
629         md_wakeup_thread(mddev->thread);
630         spin_unlock(&pers_lock);
631 }
632 
633 static struct md_rdev * find_rdev_nr(struct mddev *mddev, int nr)
634 {
635         struct md_rdev *rdev;
636 
637         rdev_for_each(rdev, mddev)
638                 if (rdev->desc_nr == nr)
639                         return rdev;
640 
641         return NULL;
642 }
643 
644 static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
645 {
646         struct md_rdev *rdev;
647 
648         rdev_for_each_rcu(rdev, mddev)
649                 if (rdev->desc_nr == nr)
650                         return rdev;
651 
652         return NULL;
653 }
654 
655 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
656 {
657         struct md_rdev *rdev;
658 
659         rdev_for_each(rdev, mddev)
660                 if (rdev->bdev->bd_dev == dev)
661                         return rdev;
662 
663         return NULL;
664 }
665 
666 static struct md_rdev *find_rdev_rcu(struct mddev *mddev, dev_t dev)
667 {
668         struct md_rdev *rdev;
669 
670         rdev_for_each_rcu(rdev, mddev)
671                 if (rdev->bdev->bd_dev == dev)
672                         return rdev;
673 
674         return NULL;
675 }
676 
677 static struct md_personality *find_pers(int level, char *clevel)
678 {
679         struct md_personality *pers;
680         list_for_each_entry(pers, &pers_list, list) {
681                 if (level != LEVEL_NONE && pers->level == level)
682                         return pers;
683                 if (strcmp(pers->name, clevel)==0)
684                         return pers;
685         }
686         return NULL;
687 }
688 
689 /* return the offset of the super block in 512byte sectors */
690 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
691 {
692         sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
693         return MD_NEW_SIZE_SECTORS(num_sectors);
694 }
695 
696 static int alloc_disk_sb(struct md_rdev * rdev)
697 {
698         if (rdev->sb_page)
699                 MD_BUG();
700 
701         rdev->sb_page = alloc_page(GFP_KERNEL);
702         if (!rdev->sb_page) {
703                 printk(KERN_ALERT "md: out of memory.\n");
704                 return -ENOMEM;
705         }
706 
707         return 0;
708 }
709 
710 void md_rdev_clear(struct md_rdev *rdev)
711 {
712         if (rdev->sb_page) {
713                 put_page(rdev->sb_page);
714                 rdev->sb_loaded = 0;
715                 rdev->sb_page = NULL;
716                 rdev->sb_start = 0;
717                 rdev->sectors = 0;
718         }
719         if (rdev->bb_page) {
720                 put_page(rdev->bb_page);
721                 rdev->bb_page = NULL;
722         }
723         kfree(rdev->badblocks.page);
724         rdev->badblocks.page = NULL;
725 }
726 EXPORT_SYMBOL_GPL(md_rdev_clear);
727 
728 static void super_written(struct bio *bio, int error)
729 {
730         struct md_rdev *rdev = bio->bi_private;
731         struct mddev *mddev = rdev->mddev;
732 
733         if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
734                 printk("md: super_written gets error=%d, uptodate=%d\n",
735                        error, test_bit(BIO_UPTODATE, &bio->bi_flags));
736                 WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
737                 md_error(mddev, rdev);
738         }
739 
740         if (atomic_dec_and_test(&mddev->pending_writes))
741                 wake_up(&mddev->sb_wait);
742         bio_put(bio);
743 }
744 
745 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
746                    sector_t sector, int size, struct page *page)
747 {
748         /* write first size bytes of page to sector of rdev
749          * Increment mddev->pending_writes before returning
750          * and decrement it on completion, waking up sb_wait
751          * if zero is reached.
752          * If an error occurred, call md_error
753          */
754         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
755 
756         bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
757         bio->bi_iter.bi_sector = sector;
758         bio_add_page(bio, page, size, 0);
759         bio->bi_private = rdev;
760         bio->bi_end_io = super_written;
761 
762         atomic_inc(&mddev->pending_writes);
763         submit_bio(WRITE_FLUSH_FUA, bio);
764 }
765 
766 void md_super_wait(struct mddev *mddev)
767 {
768         /* wait for all superblock writes that were scheduled to complete */
769         DEFINE_WAIT(wq);
770         for(;;) {
771                 prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
772                 if (atomic_read(&mddev->pending_writes)==0)
773                         break;
774                 schedule();
775         }
776         finish_wait(&mddev->sb_wait, &wq);
777 }
778 
779 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
780                  struct page *page, int rw, bool metadata_op)
781 {
782         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
783         int ret;
784 
785         bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
786                 rdev->meta_bdev : rdev->bdev;
787         if (metadata_op)
788                 bio->bi_iter.bi_sector = sector + rdev->sb_start;
789         else if (rdev->mddev->reshape_position != MaxSector &&
790                  (rdev->mddev->reshape_backwards ==
791                   (sector >= rdev->mddev->reshape_position)))
792                 bio->bi_iter.bi_sector = sector + rdev->new_data_offset;
793         else
794                 bio->bi_iter.bi_sector = sector + rdev->data_offset;
795         bio_add_page(bio, page, size, 0);
796         submit_bio_wait(rw, bio);
797 
798         ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
799         bio_put(bio);
800         return ret;
801 }
802 EXPORT_SYMBOL_GPL(sync_page_io);
803 
804 static int read_disk_sb(struct md_rdev * rdev, int size)
805 {
806         char b[BDEVNAME_SIZE];
807         if (!rdev->sb_page) {
808                 MD_BUG();
809                 return -EINVAL;
810         }
811         if (rdev->sb_loaded)
812                 return 0;
813 
814 
815         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
816                 goto fail;
817         rdev->sb_loaded = 1;
818         return 0;
819 
820 fail:
821         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
822                 bdevname(rdev->bdev,b));
823         return -EINVAL;
824 }
825 
826 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
827 {
828         return  sb1->set_uuid0 == sb2->set_uuid0 &&
829                 sb1->set_uuid1 == sb2->set_uuid1 &&
830                 sb1->set_uuid2 == sb2->set_uuid2 &&
831                 sb1->set_uuid3 == sb2->set_uuid3;
832 }
833 
834 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
835 {
836         int ret;
837         mdp_super_t *tmp1, *tmp2;
838 
839         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
840         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
841 
842         if (!tmp1 || !tmp2) {
843                 ret = 0;
844                 printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
845                 goto abort;
846         }
847 
848         *tmp1 = *sb1;
849         *tmp2 = *sb2;
850 
851         /*
852          * nr_disks is not constant
853          */
854         tmp1->nr_disks = 0;
855         tmp2->nr_disks = 0;
856 
857         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
858 abort:
859         kfree(tmp1);
860         kfree(tmp2);
861         return ret;
862 }
863 
864 
865 static u32 md_csum_fold(u32 csum)
866 {
867         csum = (csum & 0xffff) + (csum >> 16);
868         return (csum & 0xffff) + (csum >> 16);
869 }
870 
871 static unsigned int calc_sb_csum(mdp_super_t * sb)
872 {
873         u64 newcsum = 0;
874         u32 *sb32 = (u32*)sb;
875         int i;
876         unsigned int disk_csum, csum;
877 
878         disk_csum = sb->sb_csum;
879         sb->sb_csum = 0;
880 
881         for (i = 0; i < MD_SB_BYTES/4 ; i++)
882                 newcsum += sb32[i];
883         csum = (newcsum & 0xffffffff) + (newcsum>>32);
884 
885 
886 #ifdef CONFIG_ALPHA
887         /* This used to use csum_partial, which was wrong for several
888          * reasons including that different results are returned on
889          * different architectures.  It isn't critical that we get exactly
890          * the same return value as before (we always csum_fold before
891          * testing, and that removes any differences).  However as we
892          * know that csum_partial always returned a 16bit value on
893          * alphas, do a fold to maximise conformity to previous behaviour.
894          */
895         sb->sb_csum = md_csum_fold(disk_csum);
896 #else
897         sb->sb_csum = disk_csum;
898 #endif
899         return csum;
900 }
901 
902 
903 /*
904  * Handle superblock details.
905  * We want to be able to handle multiple superblock formats
906  * so we have a common interface to them all, and an array of
907  * different handlers.
908  * We rely on user-space to write the initial superblock, and support
909  * reading and updating of superblocks.
910  * Interface methods are:
911  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
912  *      loads and validates a superblock on dev.
913  *      if refdev != NULL, compare superblocks on both devices
914  *    Return:
915  *      0 - dev has a superblock that is compatible with refdev
916  *      1 - dev has a superblock that is compatible and newer than refdev
917  *          so dev should be used as the refdev in future
918  *     -EINVAL superblock incompatible or invalid
919  *     -othererror e.g. -EIO
920  *
921  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
922  *      Verify that dev is acceptable into mddev.
923  *       The first time, mddev->raid_disks will be 0, and data from
924  *       dev should be merged in.  Subsequent calls check that dev
925  *       is new enough.  Return 0 or -EINVAL
926  *
927  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
928  *     Update the superblock for rdev with data in mddev
929  *     This does not write to disc.
930  *
931  */
932 
933 struct super_type  {
934         char                *name;
935         struct module       *owner;
936         int                 (*load_super)(struct md_rdev *rdev,
937                                           struct md_rdev *refdev,
938                                           int minor_version);
939         int                 (*validate_super)(struct mddev *mddev,
940                                               struct md_rdev *rdev);
941         void                (*sync_super)(struct mddev *mddev,
942                                           struct md_rdev *rdev);
943         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
944                                                 sector_t num_sectors);
945         int                 (*allow_new_offset)(struct md_rdev *rdev,
946                                                 unsigned long long new_offset);
947 };
948 
949 /*
950  * Check that the given mddev has no bitmap.
951  *
952  * This function is called from the run method of all personalities that do not
953  * support bitmaps. It prints an error message and returns non-zero if mddev
954  * has a bitmap. Otherwise, it returns 0.
955  *
956  */
957 int md_check_no_bitmap(struct mddev *mddev)
958 {
959         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
960                 return 0;
961         printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
962                 mdname(mddev), mddev->pers->name);
963         return 1;
964 }
965 EXPORT_SYMBOL(md_check_no_bitmap);
966 
967 /*
968  * load_super for 0.90.0 
969  */
970 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
971 {
972         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
973         mdp_super_t *sb;
974         int ret;
975 
976         /*
977          * Calculate the position of the superblock (512byte sectors),
978          * it's at the end of the disk.
979          *
980          * It also happens to be a multiple of 4Kb.
981          */
982         rdev->sb_start = calc_dev_sboffset(rdev);
983 
984         ret = read_disk_sb(rdev, MD_SB_BYTES);
985         if (ret) return ret;
986 
987         ret = -EINVAL;
988 
989         bdevname(rdev->bdev, b);
990         sb = page_address(rdev->sb_page);
991 
992         if (sb->md_magic != MD_SB_MAGIC) {
993                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
994                        b);
995                 goto abort;
996         }
997 
998         if (sb->major_version != 0 ||
999             sb->minor_version < 90 ||
1000             sb->minor_version > 91) {
1001                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1002                         sb->major_version, sb->minor_version,
1003                         b);
1004                 goto abort;
1005         }
1006 
1007         if (sb->raid_disks <= 0)
1008                 goto abort;
1009 
1010         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1011                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1012                         b);
1013                 goto abort;
1014         }
1015 
1016         rdev->preferred_minor = sb->md_minor;
1017         rdev->data_offset = 0;
1018         rdev->new_data_offset = 0;
1019         rdev->sb_size = MD_SB_BYTES;
1020         rdev->badblocks.shift = -1;
1021 
1022         if (sb->level == LEVEL_MULTIPATH)
1023                 rdev->desc_nr = -1;
1024         else
1025                 rdev->desc_nr = sb->this_disk.number;
1026 
1027         if (!refdev) {
1028                 ret = 1;
1029         } else {
1030                 __u64 ev1, ev2;
1031                 mdp_super_t *refsb = page_address(refdev->sb_page);
1032                 if (!uuid_equal(refsb, sb)) {
1033                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
1034                                 b, bdevname(refdev->bdev,b2));
1035                         goto abort;
1036                 }
1037                 if (!sb_equal(refsb, sb)) {
1038                         printk(KERN_WARNING "md: %s has same UUID"
1039                                " but different superblock to %s\n",
1040                                b, bdevname(refdev->bdev, b2));
1041                         goto abort;
1042                 }
1043                 ev1 = md_event(sb);
1044                 ev2 = md_event(refsb);
1045                 if (ev1 > ev2)
1046                         ret = 1;
1047                 else 
1048                         ret = 0;
1049         }
1050         rdev->sectors = rdev->sb_start;
1051         /* Limit to 4TB as metadata cannot record more than that.
1052          * (not needed for Linear and RAID0 as metadata doesn't
1053          * record this size)
1054          */
1055         if (rdev->sectors >= (2ULL << 32) && sb->level >= 1)
1056                 rdev->sectors = (2ULL << 32) - 2;
1057 
1058         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1059                 /* "this cannot possibly happen" ... */
1060                 ret = -EINVAL;
1061 
1062  abort:
1063         return ret;
1064 }
1065 
1066 /*
1067  * validate_super for 0.90.0
1068  */
1069 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1070 {
1071         mdp_disk_t *desc;
1072         mdp_super_t *sb = page_address(rdev->sb_page);
1073         __u64 ev1 = md_event(sb);
1074 
1075         rdev->raid_disk = -1;
1076         clear_bit(Faulty, &rdev->flags);
1077         clear_bit(In_sync, &rdev->flags);
1078         clear_bit(Bitmap_sync, &rdev->flags);
1079         clear_bit(WriteMostly, &rdev->flags);
1080 
1081         if (mddev->raid_disks == 0) {
1082                 mddev->major_version = 0;
1083                 mddev->minor_version = sb->minor_version;
1084                 mddev->patch_version = sb->patch_version;
1085                 mddev->external = 0;
1086                 mddev->chunk_sectors = sb->chunk_size >> 9;
1087                 mddev->ctime = sb->ctime;
1088                 mddev->utime = sb->utime;
1089                 mddev->level = sb->level;
1090                 mddev->clevel[0] = 0;
1091                 mddev->layout = sb->layout;
1092                 mddev->raid_disks = sb->raid_disks;
1093                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1094                 mddev->events = ev1;
1095                 mddev->bitmap_info.offset = 0;
1096                 mddev->bitmap_info.space = 0;
1097                 /* bitmap can use 60 K after the 4K superblocks */
1098                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1099                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1100                 mddev->reshape_backwards = 0;
1101 
1102                 if (mddev->minor_version >= 91) {
1103                         mddev->reshape_position = sb->reshape_position;
1104                         mddev->delta_disks = sb->delta_disks;
1105                         mddev->new_level = sb->new_level;
1106                         mddev->new_layout = sb->new_layout;
1107                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1108                         if (mddev->delta_disks < 0)
1109                                 mddev->reshape_backwards = 1;
1110                 } else {
1111                         mddev->reshape_position = MaxSector;
1112                         mddev->delta_disks = 0;
1113                         mddev->new_level = mddev->level;
1114                         mddev->new_layout = mddev->layout;
1115                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1116                 }
1117 
1118                 if (sb->state & (1<<MD_SB_CLEAN))
1119                         mddev->recovery_cp = MaxSector;
1120                 else {
1121                         if (sb->events_hi == sb->cp_events_hi && 
1122                                 sb->events_lo == sb->cp_events_lo) {
1123                                 mddev->recovery_cp = sb->recovery_cp;
1124                         } else
1125                                 mddev->recovery_cp = 0;
1126                 }
1127 
1128                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1129                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1130                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1131                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1132 
1133                 mddev->max_disks = MD_SB_DISKS;
1134 
1135                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1136                     mddev->bitmap_info.file == NULL) {
1137                         mddev->bitmap_info.offset =
1138                                 mddev->bitmap_info.default_offset;
1139                         mddev->bitmap_info.space =
1140                                 mddev->bitmap_info.default_space;
1141                 }
1142 
1143         } else if (mddev->pers == NULL) {
1144                 /* Insist on good event counter while assembling, except
1145                  * for spares (which don't need an event count) */
1146                 ++ev1;
1147                 if (sb->disks[rdev->desc_nr].state & (
1148                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1149                         if (ev1 < mddev->events) 
1150                                 return -EINVAL;
1151         } else if (mddev->bitmap) {
1152                 /* if adding to array with a bitmap, then we can accept an
1153                  * older device ... but not too old.
1154                  */
1155                 if (ev1 < mddev->bitmap->events_cleared)
1156                         return 0;
1157                 if (ev1 < mddev->events)
1158                         set_bit(Bitmap_sync, &rdev->flags);
1159         } else {
1160                 if (ev1 < mddev->events)
1161                         /* just a hot-add of a new device, leave raid_disk at -1 */
1162                         return 0;
1163         }
1164 
1165         if (mddev->level != LEVEL_MULTIPATH) {
1166                 desc = sb->disks + rdev->desc_nr;
1167 
1168                 if (desc->state & (1<<MD_DISK_FAULTY))
1169                         set_bit(Faulty, &rdev->flags);
1170                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1171                             desc->raid_disk < mddev->raid_disks */) {
1172                         set_bit(In_sync, &rdev->flags);
1173                         rdev->raid_disk = desc->raid_disk;
1174                         rdev->saved_raid_disk = desc->raid_disk;
1175                 } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1176                         /* active but not in sync implies recovery up to
1177                          * reshape position.  We don't know exactly where
1178                          * that is, so set to zero for now */
1179                         if (mddev->minor_version >= 91) {
1180                                 rdev->recovery_offset = 0;
1181                                 rdev->raid_disk = desc->raid_disk;
1182                         }
1183                 }
1184                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1185                         set_bit(WriteMostly, &rdev->flags);
1186         } else /* MULTIPATH are always insync */
1187                 set_bit(In_sync, &rdev->flags);
1188         return 0;
1189 }
1190 
1191 /*
1192  * sync_super for 0.90.0
1193  */
1194 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1195 {
1196         mdp_super_t *sb;
1197         struct md_rdev *rdev2;
1198         int next_spare = mddev->raid_disks;
1199 
1200 
1201         /* make rdev->sb match mddev data..
1202          *
1203          * 1/ zero out disks
1204          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1205          * 3/ any empty disks < next_spare become removed
1206          *
1207          * disks[0] gets initialised to REMOVED because
1208          * we cannot be sure from other fields if it has
1209          * been initialised or not.
1210          */
1211         int i;
1212         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1213 
1214         rdev->sb_size = MD_SB_BYTES;
1215 
1216         sb = page_address(rdev->sb_page);
1217 
1218         memset(sb, 0, sizeof(*sb));
1219 
1220         sb->md_magic = MD_SB_MAGIC;
1221         sb->major_version = mddev->major_version;
1222         sb->patch_version = mddev->patch_version;
1223         sb->gvalid_words  = 0; /* ignored */
1224         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1225         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1226         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1227         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1228 
1229         sb->ctime = mddev->ctime;
1230         sb->level = mddev->level;
1231         sb->size = mddev->dev_sectors / 2;
1232         sb->raid_disks = mddev->raid_disks;
1233         sb->md_minor = mddev->md_minor;
1234         sb->not_persistent = 0;
1235         sb->utime = mddev->utime;
1236         sb->state = 0;
1237         sb->events_hi = (mddev->events>>32);
1238         sb->events_lo = (u32)mddev->events;
1239 
1240         if (mddev->reshape_position == MaxSector)
1241                 sb->minor_version = 90;
1242         else {
1243                 sb->minor_version = 91;
1244                 sb->reshape_position = mddev->reshape_position;
1245                 sb->new_level = mddev->new_level;
1246                 sb->delta_disks = mddev->delta_disks;
1247                 sb->new_layout = mddev->new_layout;
1248                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1249         }
1250         mddev->minor_version = sb->minor_version;
1251         if (mddev->in_sync)
1252         {
1253                 sb->recovery_cp = mddev->recovery_cp;
1254                 sb->cp_events_hi = (mddev->events>>32);
1255                 sb->cp_events_lo = (u32)mddev->events;
1256                 if (mddev->recovery_cp == MaxSector)
1257                         sb->state = (1<< MD_SB_CLEAN);
1258         } else
1259                 sb->recovery_cp = 0;
1260 
1261         sb->layout = mddev->layout;
1262         sb->chunk_size = mddev->chunk_sectors << 9;
1263 
1264         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1265                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1266 
1267         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1268         rdev_for_each(rdev2, mddev) {
1269                 mdp_disk_t *d;
1270                 int desc_nr;
1271                 int is_active = test_bit(In_sync, &rdev2->flags);
1272 
1273                 if (rdev2->raid_disk >= 0 &&
1274                     sb->minor_version >= 91)
1275                         /* we have nowhere to store the recovery_offset,
1276                          * but if it is not below the reshape_position,
1277                          * we can piggy-back on that.
1278                          */
1279                         is_active = 1;
1280                 if (rdev2->raid_disk < 0 ||
1281                     test_bit(Faulty, &rdev2->flags))
1282                         is_active = 0;
1283                 if (is_active)
1284                         desc_nr = rdev2->raid_disk;
1285                 else
1286                         desc_nr = next_spare++;
1287                 rdev2->desc_nr = desc_nr;
1288                 d = &sb->disks[rdev2->desc_nr];
1289                 nr_disks++;
1290                 d->number = rdev2->desc_nr;
1291                 d->major = MAJOR(rdev2->bdev->bd_dev);
1292                 d->minor = MINOR(rdev2->bdev->bd_dev);
1293                 if (is_active)
1294                         d->raid_disk = rdev2->raid_disk;
1295                 else
1296                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1297                 if (test_bit(Faulty, &rdev2->flags))
1298                         d->state = (1<<MD_DISK_FAULTY);
1299                 else if (is_active) {
1300                         d->state = (1<<MD_DISK_ACTIVE);
1301                         if (test_bit(In_sync, &rdev2->flags))
1302                                 d->state |= (1<<MD_DISK_SYNC);
1303                         active++;
1304                         working++;
1305                 } else {
1306                         d->state = 0;
1307                         spare++;
1308                         working++;
1309                 }
1310                 if (test_bit(WriteMostly, &rdev2->flags))
1311                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1312         }
1313         /* now set the "removed" and "faulty" bits on any missing devices */
1314         for (i=0 ; i < mddev->raid_disks ; i++) {
1315                 mdp_disk_t *d = &sb->disks[i];
1316                 if (d->state == 0 && d->number == 0) {
1317                         d->number = i;
1318                         d->raid_disk = i;
1319                         d->state = (1<<MD_DISK_REMOVED);
1320                         d->state |= (1<<MD_DISK_FAULTY);
1321                         failed++;
1322                 }
1323         }
1324         sb->nr_disks = nr_disks;
1325         sb->active_disks = active;
1326         sb->working_disks = working;
1327         sb->failed_disks = failed;
1328         sb->spare_disks = spare;
1329 
1330         sb->this_disk = sb->disks[rdev->desc_nr];
1331         sb->sb_csum = calc_sb_csum(sb);
1332 }
1333 
1334 /*
1335  * rdev_size_change for 0.90.0
1336  */
1337 static unsigned long long
1338 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1339 {
1340         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1341                 return 0; /* component must fit device */
1342         if (rdev->mddev->bitmap_info.offset)
1343                 return 0; /* can't move bitmap */
1344         rdev->sb_start = calc_dev_sboffset(rdev);
1345         if (!num_sectors || num_sectors > rdev->sb_start)
1346                 num_sectors = rdev->sb_start;
1347         /* Limit to 4TB as metadata cannot record more than that.
1348          * 4TB == 2^32 KB, or 2*2^32 sectors.
1349          */
1350         if (num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
1351                 num_sectors = (2ULL << 32) - 2;
1352         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1353                        rdev->sb_page);
1354         md_super_wait(rdev->mddev);
1355         return num_sectors;
1356 }
1357 
1358 static int
1359 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1360 {
1361         /* non-zero offset changes not possible with v0.90 */
1362         return new_offset == 0;
1363 }
1364 
1365 /*
1366  * version 1 superblock
1367  */
1368 
1369 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1370 {
1371         __le32 disk_csum;
1372         u32 csum;
1373         unsigned long long newcsum;
1374         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1375         __le32 *isuper = (__le32*)sb;
1376 
1377         disk_csum = sb->sb_csum;
1378         sb->sb_csum = 0;
1379         newcsum = 0;
1380         for (; size >= 4; size -= 4)
1381                 newcsum += le32_to_cpu(*isuper++);
1382 
1383         if (size == 2)
1384                 newcsum += le16_to_cpu(*(__le16*) isuper);
1385 
1386         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1387         sb->sb_csum = disk_csum;
1388         return cpu_to_le32(csum);
1389 }
1390 
1391 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1392                             int acknowledged);
1393 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1394 {
1395         struct mdp_superblock_1 *sb;
1396         int ret;
1397         sector_t sb_start;
1398         sector_t sectors;
1399         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1400         int bmask;
1401 
1402         /*
1403          * Calculate the position of the superblock in 512byte sectors.
1404          * It is always aligned to a 4K boundary and
1405          * depeding on minor_version, it can be:
1406          * 0: At least 8K, but less than 12K, from end of device
1407          * 1: At start of device
1408          * 2: 4K from start of device.
1409          */
1410         switch(minor_version) {
1411         case 0:
1412                 sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1413                 sb_start -= 8*2;
1414                 sb_start &= ~(sector_t)(4*2-1);
1415                 break;
1416         case 1:
1417                 sb_start = 0;
1418                 break;
1419         case 2:
1420                 sb_start = 8;
1421                 break;
1422         default:
1423                 return -EINVAL;
1424         }
1425         rdev->sb_start = sb_start;
1426 
1427         /* superblock is rarely larger than 1K, but it can be larger,
1428          * and it is safe to read 4k, so we do that
1429          */
1430         ret = read_disk_sb(rdev, 4096);
1431         if (ret) return ret;
1432 
1433 
1434         sb = page_address(rdev->sb_page);
1435 
1436         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1437             sb->major_version != cpu_to_le32(1) ||
1438             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1439             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1440             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1441                 return -EINVAL;
1442 
1443         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1444                 printk("md: invalid superblock checksum on %s\n",
1445                         bdevname(rdev->bdev,b));
1446                 return -EINVAL;
1447         }
1448         if (le64_to_cpu(sb->data_size) < 10) {
1449                 printk("md: data_size too small on %s\n",
1450                        bdevname(rdev->bdev,b));
1451                 return -EINVAL;
1452         }
1453         if (sb->pad0 ||
1454             sb->pad3[0] ||
1455             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1456                 /* Some padding is non-zero, might be a new feature */
1457                 return -EINVAL;
1458 
1459         rdev->preferred_minor = 0xffff;
1460         rdev->data_offset = le64_to_cpu(sb->data_offset);
1461         rdev->new_data_offset = rdev->data_offset;
1462         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1463             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1464                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1465         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1466 
1467         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1468         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1469         if (rdev->sb_size & bmask)
1470                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1471 
1472         if (minor_version
1473             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1474                 return -EINVAL;
1475         if (minor_version
1476             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1477                 return -EINVAL;
1478 
1479         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1480                 rdev->desc_nr = -1;
1481         else
1482                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1483 
1484         if (!rdev->bb_page) {
1485                 rdev->bb_page = alloc_page(GFP_KERNEL);
1486                 if (!rdev->bb_page)
1487                         return -ENOMEM;
1488         }
1489         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1490             rdev->badblocks.count == 0) {
1491                 /* need to load the bad block list.
1492                  * Currently we limit it to one page.
1493                  */
1494                 s32 offset;
1495                 sector_t bb_sector;
1496                 u64 *bbp;
1497                 int i;
1498                 int sectors = le16_to_cpu(sb->bblog_size);
1499                 if (sectors > (PAGE_SIZE / 512))
1500                         return -EINVAL;
1501                 offset = le32_to_cpu(sb->bblog_offset);
1502                 if (offset == 0)
1503                         return -EINVAL;
1504                 bb_sector = (long long)offset;
1505                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1506                                   rdev->bb_page, READ, true))
1507                         return -EIO;
1508                 bbp = (u64 *)page_address(rdev->bb_page);
1509                 rdev->badblocks.shift = sb->bblog_shift;
1510                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1511                         u64 bb = le64_to_cpu(*bbp);
1512                         int count = bb & (0x3ff);
1513                         u64 sector = bb >> 10;
1514                         sector <<= sb->bblog_shift;
1515                         count <<= sb->bblog_shift;
1516                         if (bb + 1 == 0)
1517                                 break;
1518                         if (md_set_badblocks(&rdev->badblocks,
1519                                              sector, count, 1) == 0)
1520                                 return -EINVAL;
1521                 }
1522         } else if (sb->bblog_offset != 0)
1523                 rdev->badblocks.shift = 0;
1524 
1525         if (!refdev) {
1526                 ret = 1;
1527         } else {
1528                 __u64 ev1, ev2;
1529                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1530 
1531                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1532                     sb->level != refsb->level ||
1533                     sb->layout != refsb->layout ||
1534                     sb->chunksize != refsb->chunksize) {
1535                         printk(KERN_WARNING "md: %s has strangely different"
1536                                 " superblock to %s\n",
1537                                 bdevname(rdev->bdev,b),
1538                                 bdevname(refdev->bdev,b2));
1539                         return -EINVAL;
1540                 }
1541                 ev1 = le64_to_cpu(sb->events);
1542                 ev2 = le64_to_cpu(refsb->events);
1543 
1544                 if (ev1 > ev2)
1545                         ret = 1;
1546                 else
1547                         ret = 0;
1548         }
1549         if (minor_version) {
1550                 sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1551                 sectors -= rdev->data_offset;
1552         } else
1553                 sectors = rdev->sb_start;
1554         if (sectors < le64_to_cpu(sb->data_size))
1555                 return -EINVAL;
1556         rdev->sectors = le64_to_cpu(sb->data_size);
1557         return ret;
1558 }
1559 
1560 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1561 {
1562         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1563         __u64 ev1 = le64_to_cpu(sb->events);
1564 
1565         rdev->raid_disk = -1;
1566         clear_bit(Faulty, &rdev->flags);
1567         clear_bit(In_sync, &rdev->flags);
1568         clear_bit(Bitmap_sync, &rdev->flags);
1569         clear_bit(WriteMostly, &rdev->flags);
1570 
1571         if (mddev->raid_disks == 0) {
1572                 mddev->major_version = 1;
1573                 mddev->patch_version = 0;
1574                 mddev->external = 0;
1575                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1576                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1577                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1578                 mddev->level = le32_to_cpu(sb->level);
1579                 mddev->clevel[0] = 0;
1580                 mddev->layout = le32_to_cpu(sb->layout);
1581                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1582                 mddev->dev_sectors = le64_to_cpu(sb->size);
1583                 mddev->events = ev1;
1584                 mddev->bitmap_info.offset = 0;
1585                 mddev->bitmap_info.space = 0;
1586                 /* Default location for bitmap is 1K after superblock
1587                  * using 3K - total of 4K
1588                  */
1589                 mddev->bitmap_info.default_offset = 1024 >> 9;
1590                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1591                 mddev->reshape_backwards = 0;
1592 
1593                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1594                 memcpy(mddev->uuid, sb->set_uuid, 16);
1595 
1596                 mddev->max_disks =  (4096-256)/2;
1597 
1598                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1599                     mddev->bitmap_info.file == NULL) {
1600                         mddev->bitmap_info.offset =
1601                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1602                         /* Metadata doesn't record how much space is available.
1603                          * For 1.0, we assume we can use up to the superblock
1604                          * if before, else to 4K beyond superblock.
1605                          * For others, assume no change is possible.
1606                          */
1607                         if (mddev->minor_version > 0)
1608                                 mddev->bitmap_info.space = 0;
1609                         else if (mddev->bitmap_info.offset > 0)
1610                                 mddev->bitmap_info.space =
1611                                         8 - mddev->bitmap_info.offset;
1612                         else
1613                                 mddev->bitmap_info.space =
1614                                         -mddev->bitmap_info.offset;
1615                 }
1616 
1617                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1618                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1619                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1620                         mddev->new_level = le32_to_cpu(sb->new_level);
1621                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1622                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1623                         if (mddev->delta_disks < 0 ||
1624                             (mddev->delta_disks == 0 &&
1625                              (le32_to_cpu(sb->feature_map)
1626                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1627                                 mddev->reshape_backwards = 1;
1628                 } else {
1629                         mddev->reshape_position = MaxSector;
1630                         mddev->delta_disks = 0;
1631                         mddev->new_level = mddev->level;
1632                         mddev->new_layout = mddev->layout;
1633                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1634                 }
1635 
1636         } else if (mddev->pers == NULL) {
1637                 /* Insist of good event counter while assembling, except for
1638                  * spares (which don't need an event count) */
1639                 ++ev1;
1640                 if (rdev->desc_nr >= 0 &&
1641                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1642                     le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1643                         if (ev1 < mddev->events)
1644                                 return -EINVAL;
1645         } else if (mddev->bitmap) {
1646                 /* If adding to array with a bitmap, then we can accept an
1647                  * older device, but not too old.
1648                  */
1649                 if (ev1 < mddev->bitmap->events_cleared)
1650                         return 0;
1651                 if (ev1 < mddev->events)
1652                         set_bit(Bitmap_sync, &rdev->flags);
1653         } else {
1654                 if (ev1 < mddev->events)
1655                         /* just a hot-add of a new device, leave raid_disk at -1 */
1656                         return 0;
1657         }
1658         if (mddev->level != LEVEL_MULTIPATH) {
1659                 int role;
1660                 if (rdev->desc_nr < 0 ||
1661                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1662                         role = 0xffff;
1663                         rdev->desc_nr = -1;
1664                 } else
1665                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1666                 switch(role) {
1667                 case 0xffff: /* spare */
1668                         break;
1669                 case 0xfffe: /* faulty */
1670                         set_bit(Faulty, &rdev->flags);
1671                         break;
1672                 default:
1673                         rdev->saved_raid_disk = role;
1674                         if ((le32_to_cpu(sb->feature_map) &
1675                              MD_FEATURE_RECOVERY_OFFSET)) {
1676                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1677                                 if (!(le32_to_cpu(sb->feature_map) &
1678                                       MD_FEATURE_RECOVERY_BITMAP))
1679                                         rdev->saved_raid_disk = -1;
1680                         } else
1681                                 set_bit(In_sync, &rdev->flags);
1682                         rdev->raid_disk = role;
1683                         break;
1684                 }
1685                 if (sb->devflags & WriteMostly1)
1686                         set_bit(WriteMostly, &rdev->flags);
1687                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1688                         set_bit(Replacement, &rdev->flags);
1689         } else /* MULTIPATH are always insync */
1690                 set_bit(In_sync, &rdev->flags);
1691 
1692         return 0;
1693 }
1694 
1695 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1696 {
1697         struct mdp_superblock_1 *sb;
1698         struct md_rdev *rdev2;
1699         int max_dev, i;
1700         /* make rdev->sb match mddev and rdev data. */
1701 
1702         sb = page_address(rdev->sb_page);
1703 
1704         sb->feature_map = 0;
1705         sb->pad0 = 0;
1706         sb->recovery_offset = cpu_to_le64(0);
1707         memset(sb->pad3, 0, sizeof(sb->pad3));
1708 
1709         sb->utime = cpu_to_le64((__u64)mddev->utime);
1710         sb->events = cpu_to_le64(mddev->events);
1711         if (mddev->in_sync)
1712                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1713         else
1714                 sb->resync_offset = cpu_to_le64(0);
1715 
1716         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1717 
1718         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1719         sb->size = cpu_to_le64(mddev->dev_sectors);
1720         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1721         sb->level = cpu_to_le32(mddev->level);
1722         sb->layout = cpu_to_le32(mddev->layout);
1723 
1724         if (test_bit(WriteMostly, &rdev->flags))
1725                 sb->devflags |= WriteMostly1;
1726         else
1727                 sb->devflags &= ~WriteMostly1;
1728         sb->data_offset = cpu_to_le64(rdev->data_offset);
1729         sb->data_size = cpu_to_le64(rdev->sectors);
1730 
1731         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1732                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1733                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1734         }
1735 
1736         if (rdev->raid_disk >= 0 &&
1737             !test_bit(In_sync, &rdev->flags)) {
1738                 sb->feature_map |=
1739                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1740                 sb->recovery_offset =
1741                         cpu_to_le64(rdev->recovery_offset);
1742                 if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
1743                         sb->feature_map |=
1744                                 cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
1745         }
1746         if (test_bit(Replacement, &rdev->flags))
1747                 sb->feature_map |=
1748                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
1749 
1750         if (mddev->reshape_position != MaxSector) {
1751                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1752                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1753                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1754                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1755                 sb->new_level = cpu_to_le32(mddev->new_level);
1756                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1757                 if (mddev->delta_disks == 0 &&
1758                     mddev->reshape_backwards)
1759                         sb->feature_map
1760                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1761                 if (rdev->new_data_offset != rdev->data_offset) {
1762                         sb->feature_map
1763                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1764                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1765                                                              - rdev->data_offset));
1766                 }
1767         }
1768 
1769         if (rdev->badblocks.count == 0)
1770                 /* Nothing to do for bad blocks*/ ;
1771         else if (sb->bblog_offset == 0)
1772                 /* Cannot record bad blocks on this device */
1773                 md_error(mddev, rdev);
1774         else {
1775                 struct badblocks *bb = &rdev->badblocks;
1776                 u64 *bbp = (u64 *)page_address(rdev->bb_page);
1777                 u64 *p = bb->page;
1778                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1779                 if (bb->changed) {
1780                         unsigned seq;
1781 
1782 retry:
1783                         seq = read_seqbegin(&bb->lock);
1784 
1785                         memset(bbp, 0xff, PAGE_SIZE);
1786 
1787                         for (i = 0 ; i < bb->count ; i++) {
1788                                 u64 internal_bb = p[i];
1789                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1790                                                 | BB_LEN(internal_bb));
1791                                 bbp[i] = cpu_to_le64(store_bb);
1792                         }
1793                         bb->changed = 0;
1794                         if (read_seqretry(&bb->lock, seq))
1795                                 goto retry;
1796 
1797                         bb->sector = (rdev->sb_start +
1798                                       (int)le32_to_cpu(sb->bblog_offset));
1799                         bb->size = le16_to_cpu(sb->bblog_size);
1800                 }
1801         }
1802 
1803         max_dev = 0;
1804         rdev_for_each(rdev2, mddev)
1805                 if (rdev2->desc_nr+1 > max_dev)
1806                         max_dev = rdev2->desc_nr+1;
1807 
1808         if (max_dev > le32_to_cpu(sb->max_dev)) {
1809                 int bmask;
1810                 sb->max_dev = cpu_to_le32(max_dev);
1811                 rdev->sb_size = max_dev * 2 + 256;
1812                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1813                 if (rdev->sb_size & bmask)
1814                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
1815         } else
1816                 max_dev = le32_to_cpu(sb->max_dev);
1817 
1818         for (i=0; i<max_dev;i++)
1819                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
1820         
1821         rdev_for_each(rdev2, mddev) {
1822                 i = rdev2->desc_nr;
1823                 if (test_bit(Faulty, &rdev2->flags))
1824                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
1825                 else if (test_bit(In_sync, &rdev2->flags))
1826                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1827                 else if (rdev2->raid_disk >= 0)
1828                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1829                 else
1830                         sb->dev_roles[i] = cpu_to_le16(0xffff);
1831         }
1832 
1833         sb->sb_csum = calc_sb_1_csum(sb);
1834 }
1835 
1836 static unsigned long long
1837 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1838 {
1839         struct mdp_superblock_1 *sb;
1840         sector_t max_sectors;
1841         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1842                 return 0; /* component must fit device */
1843         if (rdev->data_offset != rdev->new_data_offset)
1844                 return 0; /* too confusing */
1845         if (rdev->sb_start < rdev->data_offset) {
1846                 /* minor versions 1 and 2; superblock before data */
1847                 max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1848                 max_sectors -= rdev->data_offset;
1849                 if (!num_sectors || num_sectors > max_sectors)
1850                         num_sectors = max_sectors;
1851         } else if (rdev->mddev->bitmap_info.offset) {
1852                 /* minor version 0 with bitmap we can't move */
1853                 return 0;
1854         } else {
1855                 /* minor version 0; superblock after data */
1856                 sector_t sb_start;
1857                 sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1858                 sb_start &= ~(sector_t)(4*2 - 1);
1859                 max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1860                 if (!num_sectors || num_sectors > max_sectors)
1861                         num_sectors = max_sectors;
1862                 rdev->sb_start = sb_start;
1863         }
1864         sb = page_address(rdev->sb_page);
1865         sb->data_size = cpu_to_le64(num_sectors);
1866         sb->super_offset = rdev->sb_start;
1867         sb->sb_csum = calc_sb_1_csum(sb);
1868         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1869                        rdev->sb_page);
1870         md_super_wait(rdev->mddev);
1871         return num_sectors;
1872 
1873 }
1874 
1875 static int
1876 super_1_allow_new_offset(struct md_rdev *rdev,
1877                          unsigned long long new_offset)
1878 {
1879         /* All necessary checks on new >= old have been done */
1880         struct bitmap *bitmap;
1881         if (new_offset >= rdev->data_offset)
1882                 return 1;
1883 
1884         /* with 1.0 metadata, there is no metadata to tread on
1885          * so we can always move back */
1886         if (rdev->mddev->minor_version == 0)
1887                 return 1;
1888 
1889         /* otherwise we must be sure not to step on
1890          * any metadata, so stay:
1891          * 36K beyond start of superblock
1892          * beyond end of badblocks
1893          * beyond write-intent bitmap
1894          */
1895         if (rdev->sb_start + (32+4)*2 > new_offset)
1896                 return 0;
1897         bitmap = rdev->mddev->bitmap;
1898         if (bitmap && !rdev->mddev->bitmap_info.file &&
1899             rdev->sb_start + rdev->mddev->bitmap_info.offset +
1900             bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1901                 return 0;
1902         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1903                 return 0;
1904 
1905         return 1;
1906 }
1907 
1908 static struct super_type super_types[] = {
1909         [0] = {
1910                 .name   = "0.90.0",
1911                 .owner  = THIS_MODULE,
1912                 .load_super         = super_90_load,
1913                 .validate_super     = super_90_validate,
1914                 .sync_super         = super_90_sync,
1915                 .rdev_size_change   = super_90_rdev_size_change,
1916                 .allow_new_offset   = super_90_allow_new_offset,
1917         },
1918         [1] = {
1919                 .name   = "md-1",
1920                 .owner  = THIS_MODULE,
1921                 .load_super         = super_1_load,
1922                 .validate_super     = super_1_validate,
1923                 .sync_super         = super_1_sync,
1924                 .rdev_size_change   = super_1_rdev_size_change,
1925                 .allow_new_offset   = super_1_allow_new_offset,
1926         },
1927 };
1928 
1929 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1930 {
1931         if (mddev->sync_super) {
1932                 mddev->sync_super(mddev, rdev);
1933                 return;
1934         }
1935 
1936         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1937 
1938         super_types[mddev->major_version].sync_super(mddev, rdev);
1939 }
1940 
1941 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1942 {
1943         struct md_rdev *rdev, *rdev2;
1944 
1945         rcu_read_lock();
1946         rdev_for_each_rcu(rdev, mddev1)
1947                 rdev_for_each_rcu(rdev2, mddev2)
1948                         if (rdev->bdev->bd_contains ==
1949                             rdev2->bdev->bd_contains) {
1950                                 rcu_read_unlock();
1951                                 return 1;
1952                         }
1953         rcu_read_unlock();
1954         return 0;
1955 }
1956 
1957 static LIST_HEAD(pending_raid_disks);
1958 
1959 /*
1960  * Try to register data integrity profile for an mddev
1961  *
1962  * This is called when an array is started and after a disk has been kicked
1963  * from the array. It only succeeds if all working and active component devices
1964  * are integrity capable with matching profiles.
1965  */
1966 int md_integrity_register(struct mddev *mddev)
1967 {
1968         struct md_rdev *rdev, *reference = NULL;
1969 
1970         if (list_empty(&mddev->disks))
1971                 return 0; /* nothing to do */
1972         if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1973                 return 0; /* shouldn't register, or already is */
1974         rdev_for_each(rdev, mddev) {
1975                 /* skip spares and non-functional disks */
1976                 if (test_bit(Faulty, &rdev->flags))
1977                         continue;
1978                 if (rdev->raid_disk < 0)
1979                         continue;
1980                 if (!reference) {
1981                         /* Use the first rdev as the reference */
1982                         reference = rdev;
1983                         continue;
1984                 }
1985                 /* does this rdev's profile match the reference profile? */
1986                 if (blk_integrity_compare(reference->bdev->bd_disk,
1987                                 rdev->bdev->bd_disk) < 0)
1988                         return -EINVAL;
1989         }
1990         if (!reference || !bdev_get_integrity(reference->bdev))
1991                 return 0;
1992         /*
1993          * All component devices are integrity capable and have matching
1994          * profiles, register the common profile for the md device.
1995          */
1996         if (blk_integrity_register(mddev->gendisk,
1997                         bdev_get_integrity(reference->bdev)) != 0) {
1998                 printk(KERN_ERR "md: failed to register integrity for %s\n",
1999                         mdname(mddev));
2000                 return -EINVAL;
2001         }
2002         printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2003         if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2004                 printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2005                        mdname(mddev));
2006                 return -EINVAL;
2007         }
2008         return 0;
2009 }
2010 EXPORT_SYMBOL(md_integrity_register);
2011 
2012 /* Disable data integrity if non-capable/non-matching disk is being added */
2013 void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2014 {
2015         struct blk_integrity *bi_rdev;
2016         struct blk_integrity *bi_mddev;
2017 
2018         if (!mddev->gendisk)
2019                 return;
2020 
2021         bi_rdev = bdev_get_integrity(rdev->bdev);
2022         bi_mddev = blk_get_integrity(mddev->gendisk);
2023 
2024         if (!bi_mddev) /* nothing to do */
2025                 return;
2026         if (rdev->raid_disk < 0) /* skip spares */
2027                 return;
2028         if (bi_rdev && blk_integrity_compare(mddev->gendisk,
2029                                              rdev->bdev->bd_disk) >= 0)
2030                 return;
2031         printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
2032         blk_integrity_unregister(mddev->gendisk);
2033 }
2034 EXPORT_SYMBOL(md_integrity_add_rdev);
2035 
2036 static int bind_rdev_to_array(struct md_rdev * rdev, struct mddev * mddev)
2037 {
2038         char b[BDEVNAME_SIZE];
2039         struct kobject *ko;
2040         char *s;
2041         int err;
2042 
2043         if (rdev->mddev) {
2044                 MD_BUG();
2045                 return -EINVAL;
2046         }
2047 
2048         /* prevent duplicates */
2049         if (find_rdev(mddev, rdev->bdev->bd_dev))
2050                 return -EEXIST;
2051 
2052         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2053         if (rdev->sectors && (mddev->dev_sectors == 0 ||
2054                         rdev->sectors < mddev->dev_sectors)) {
2055                 if (mddev->pers) {
2056                         /* Cannot change size, so fail
2057                          * If mddev->level <= 0, then we don't care
2058                          * about aligning sizes (e.g. linear)
2059                          */
2060                         if (mddev->level > 0)
2061                                 return -ENOSPC;
2062                 } else
2063                         mddev->dev_sectors = rdev->sectors;
2064         }
2065 
2066         /* Verify rdev->desc_nr is unique.
2067          * If it is -1, assign a free number, else
2068          * check number is not in use
2069          */
2070         if (rdev->desc_nr < 0) {
2071                 int choice = 0;
2072                 if (mddev->pers) choice = mddev->raid_disks;
2073                 while (find_rdev_nr(mddev, choice))
2074                         choice++;
2075                 rdev->desc_nr = choice;
2076         } else {
2077                 if (find_rdev_nr(mddev, rdev->desc_nr))
2078                         return -EBUSY;
2079         }
2080         if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2081                 printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2082                        mdname(mddev), mddev->max_disks);
2083                 return -EBUSY;
2084         }
2085         bdevname(rdev->bdev,b);
2086         while ( (s=strchr(b, '/')) != NULL)
2087                 *s = '!';
2088 
2089         rdev->mddev = mddev;
2090         printk(KERN_INFO "md: bind<%s>\n", b);
2091 
2092         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2093                 goto fail;
2094 
2095         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2096         if (sysfs_create_link(&rdev->kobj, ko, "block"))
2097                 /* failure here is OK */;
2098         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2099 
2100         list_add_rcu(&rdev->same_set, &mddev->disks);
2101         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2102 
2103         /* May as well allow recovery to be retried once */
2104         mddev->recovery_disabled++;
2105 
2106         return 0;
2107 
2108  fail:
2109         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2110                b, mdname(mddev));
2111         return err;
2112 }
2113 
2114 static void md_delayed_delete(struct work_struct *ws)
2115 {
2116         struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2117         kobject_del(&rdev->kobj);
2118         kobject_put(&rdev->kobj);
2119 }
2120 
2121 static void unbind_rdev_from_array(struct md_rdev * rdev)
2122 {
2123         char b[BDEVNAME_SIZE];
2124         if (!rdev->mddev) {
2125                 MD_BUG();
2126                 return;
2127         }
2128         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2129         list_del_rcu(&rdev->same_set);
2130         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2131         rdev->mddev = NULL;
2132         sysfs_remove_link(&rdev->kobj, "block");
2133         sysfs_put(rdev->sysfs_state);
2134         rdev->sysfs_state = NULL;
2135         rdev->badblocks.count = 0;
2136         /* We need to delay this, otherwise we can deadlock when
2137          * writing to 'remove' to "dev/state".  We also need
2138          * to delay it due to rcu usage.
2139          */
2140         synchronize_rcu();
2141         INIT_WORK(&rdev->del_work, md_delayed_delete);
2142         kobject_get(&rdev->kobj);
2143         queue_work(md_misc_wq, &rdev->del_work);
2144 }
2145 
2146 /*
2147  * prevent the device from being mounted, repartitioned or
2148  * otherwise reused by a RAID array (or any other kernel
2149  * subsystem), by bd_claiming the device.
2150  */
2151 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2152 {
2153         int err = 0;
2154         struct block_device *bdev;
2155         char b[BDEVNAME_SIZE];
2156 
2157         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2158                                  shared ? (struct md_rdev *)lock_rdev : rdev);
2159         if (IS_ERR(bdev)) {
2160                 printk(KERN_ERR "md: could not open %s.\n",
2161                         __bdevname(dev, b));
2162                 return PTR_ERR(bdev);
2163         }
2164         rdev->bdev = bdev;
2165         return err;
2166 }
2167 
2168 static void unlock_rdev(struct md_rdev *rdev)
2169 {
2170         struct block_device *bdev = rdev->bdev;
2171         rdev->bdev = NULL;
2172         if (!bdev)
2173                 MD_BUG();
2174         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2175 }
2176 
2177 void md_autodetect_dev(dev_t dev);
2178 
2179 static void export_rdev(struct md_rdev * rdev)
2180 {
2181         char b[BDEVNAME_SIZE];
2182         printk(KERN_INFO "md: export_rdev(%s)\n",
2183                 bdevname(rdev->bdev,b));
2184         if (rdev->mddev)
2185                 MD_BUG();
2186         md_rdev_clear(rdev);
2187 #ifndef MODULE
2188         if (test_bit(AutoDetected, &rdev->flags))
2189                 md_autodetect_dev(rdev->bdev->bd_dev);
2190 #endif
2191         unlock_rdev(rdev);
2192         kobject_put(&rdev->kobj);
2193 }
2194 
2195 static void kick_rdev_from_array(struct md_rdev * rdev)
2196 {
2197         unbind_rdev_from_array(rdev);
2198         export_rdev(rdev);
2199 }
2200 
2201 static void export_array(struct mddev *mddev)
2202 {
2203         struct md_rdev *rdev, *tmp;
2204 
2205         rdev_for_each_safe(rdev, tmp, mddev) {
2206                 if (!rdev->mddev) {
2207                         MD_BUG();
2208                         continue;
2209                 }
2210                 kick_rdev_from_array(rdev);
2211         }
2212         if (!list_empty(&mddev->disks))
2213                 MD_BUG();
2214         mddev->raid_disks = 0;
2215         mddev->major_version = 0;
2216 }
2217 
2218 static void print_desc(mdp_disk_t *desc)
2219 {
2220         printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2221                 desc->major,desc->minor,desc->raid_disk,desc->state);
2222 }
2223 
2224 static void print_sb_90(mdp_super_t *sb)
2225 {
2226         int i;
2227 
2228         printk(KERN_INFO 
2229                 "md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2230                 sb->major_version, sb->minor_version, sb->patch_version,
2231                 sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2232                 sb->ctime);
2233         printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2234                 sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2235                 sb->md_minor, sb->layout, sb->chunk_size);
2236         printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2237                 " FD:%d SD:%d CSUM:%08x E:%08lx\n",
2238                 sb->utime, sb->state, sb->active_disks, sb->working_disks,
2239                 sb->failed_disks, sb->spare_disks,
2240                 sb->sb_csum, (unsigned long)sb->events_lo);
2241 
2242         printk(KERN_INFO);
2243         for (i = 0; i < MD_SB_DISKS; i++) {
2244                 mdp_disk_t *desc;
2245 
2246                 desc = sb->disks + i;
2247                 if (desc->number || desc->major || desc->minor ||
2248                     desc->raid_disk || (desc->state && (desc->state != 4))) {
2249                         printk("     D %2d: ", i);
2250                         print_desc(desc);
2251                 }
2252         }
2253         printk(KERN_INFO "md:     THIS: ");
2254         print_desc(&sb->this_disk);
2255 }
2256 
2257 static void print_sb_1(struct mdp_superblock_1 *sb)
2258 {
2259         __u8 *uuid;
2260 
2261         uuid = sb->set_uuid;
2262         printk(KERN_INFO
2263                "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2264                "md:    Name: \"%s\" CT:%llu\n",
2265                 le32_to_cpu(sb->major_version),
2266                 le32_to_cpu(sb->feature_map),
2267                 uuid,
2268                 sb->set_name,
2269                 (unsigned long long)le64_to_cpu(sb->ctime)
2270                        & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2271 
2272         uuid = sb->device_uuid;
2273         printk(KERN_INFO
2274                "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2275                         " RO:%llu\n"
2276                "md:     Dev:%08x UUID: %pU\n"
2277                "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2278                "md:         (MaxDev:%u) \n",
2279                 le32_to_cpu(sb->level),
2280                 (unsigned long long)le64_to_cpu(sb->size),
2281                 le32_to_cpu(sb->raid_disks),
2282                 le32_to_cpu(sb->layout),
2283                 le32_to_cpu(sb->chunksize),
2284                 (unsigned long long)le64_to_cpu(sb->data_offset),
2285                 (unsigned long long)le64_to_cpu(sb->data_size),
2286                 (unsigned long long)le64_to_cpu(sb->super_offset),
2287                 (unsigned long long)le64_to_cpu(sb->recovery_offset),
2288                 le32_to_cpu(sb->dev_number),
2289                 uuid,
2290                 sb->devflags,
2291                 (unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2292                 (unsigned long long)le64_to_cpu(sb->events),
2293                 (unsigned long long)le64_to_cpu(sb->resync_offset),
2294                 le32_to_cpu(sb->sb_csum),
2295                 le32_to_cpu(sb->max_dev)
2296                 );
2297 }
2298 
2299 static void print_rdev(struct md_rdev *rdev, int major_version)
2300 {
2301         char b[BDEVNAME_SIZE];
2302         printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2303                 bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2304                 test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2305                 rdev->desc_nr);
2306         if (rdev->sb_loaded) {
2307                 printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2308                 switch (major_version) {
2309                 case 0:
2310                         print_sb_90(page_address(rdev->sb_page));
2311                         break;
2312                 case 1:
2313                         print_sb_1(page_address(rdev->sb_page));
2314                         break;
2315                 }
2316         } else
2317                 printk(KERN_INFO "md: no rdev superblock!\n");
2318 }
2319 
2320 static void md_print_devices(void)
2321 {
2322         struct list_head *tmp;
2323         struct md_rdev *rdev;
2324         struct mddev *mddev;
2325         char b[BDEVNAME_SIZE];
2326 
2327         printk("\n");
2328         printk("md:     **********************************\n");
2329         printk("md:     * <COMPLETE RAID STATE PRINTOUT> *\n");
2330         printk("md:     **********************************\n");
2331         for_each_mddev(mddev, tmp) {
2332 
2333                 if (mddev->bitmap)
2334                         bitmap_print_sb(mddev->bitmap);
2335                 else
2336                         printk("%s: ", mdname(mddev));
2337                 rdev_for_each(rdev, mddev)
2338                         printk("<%s>", bdevname(rdev->bdev,b));
2339                 printk("\n");
2340 
2341                 rdev_for_each(rdev, mddev)
2342                         print_rdev(rdev, mddev->major_version);
2343         }
2344         printk("md:     **********************************\n");
2345         printk("\n");
2346 }
2347 
2348 
2349 static void sync_sbs(struct mddev * mddev, int nospares)
2350 {
2351         /* Update each superblock (in-memory image), but
2352          * if we are allowed to, skip spares which already
2353          * have the right event counter, or have one earlier
2354          * (which would mean they aren't being marked as dirty
2355          * with the rest of the array)
2356          */
2357         struct md_rdev *rdev;
2358         rdev_for_each(rdev, mddev) {
2359                 if (rdev->sb_events == mddev->events ||
2360                     (nospares &&
2361                      rdev->raid_disk < 0 &&
2362                      rdev->sb_events+1 == mddev->events)) {
2363                         /* Don't update this superblock */
2364                         rdev->sb_loaded = 2;
2365                 } else {
2366                         sync_super(mddev, rdev);
2367                         rdev->sb_loaded = 1;
2368                 }
2369         }
2370 }
2371 
2372 static void md_update_sb(struct mddev * mddev, int force_change)
2373 {
2374         struct md_rdev *rdev;
2375         int sync_req;
2376         int nospares = 0;
2377         int any_badblocks_changed = 0;
2378 
2379         if (mddev->ro) {
2380                 if (force_change)
2381                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2382                 return;
2383         }
2384 repeat:
2385         /* First make sure individual recovery_offsets are correct */
2386         rdev_for_each(rdev, mddev) {
2387                 if (rdev->raid_disk >= 0 &&
2388                     mddev->delta_disks >= 0 &&
2389                     !test_bit(In_sync, &rdev->flags) &&
2390                     mddev->curr_resync_completed > rdev->recovery_offset)
2391                                 rdev->recovery_offset = mddev->curr_resync_completed;
2392 
2393         }       
2394         if (!mddev->persistent) {
2395                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2396                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2397                 if (!mddev->external) {
2398                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2399                         rdev_for_each(rdev, mddev) {
2400                                 if (rdev->badblocks.changed) {
2401                                         rdev->badblocks.changed = 0;
2402                                         md_ack_all_badblocks(&rdev->badblocks);
2403                                         md_error(mddev, rdev);
2404                                 }
2405                                 clear_bit(Blocked, &rdev->flags);
2406                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2407                                 wake_up(&rdev->blocked_wait);
2408                         }
2409                 }
2410                 wake_up(&mddev->sb_wait);
2411                 return;
2412         }
2413 
2414         spin_lock_irq(&mddev->write_lock);
2415 
2416         mddev->utime = get_seconds();
2417 
2418         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2419                 force_change = 1;
2420         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2421                 /* just a clean<-> dirty transition, possibly leave spares alone,
2422                  * though if events isn't the right even/odd, we will have to do
2423                  * spares after all
2424                  */
2425                 nospares = 1;
2426         if (force_change)
2427                 nospares = 0;
2428         if (mddev->degraded)
2429                 /* If the array is degraded, then skipping spares is both
2430                  * dangerous and fairly pointless.
2431                  * Dangerous because a device that was removed from the array
2432                  * might have a event_count that still looks up-to-date,
2433                  * so it can be re-added without a resync.
2434                  * Pointless because if there are any spares to skip,
2435                  * then a recovery will happen and soon that array won't
2436                  * be degraded any more and the spare can go back to sleep then.
2437                  */
2438                 nospares = 0;
2439 
2440         sync_req = mddev->in_sync;
2441 
2442         /* If this is just a dirty<->clean transition, and the array is clean
2443          * and 'events' is odd, we can roll back to the previous clean state */
2444         if (nospares
2445             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2446             && mddev->can_decrease_events
2447             && mddev->events != 1) {
2448                 mddev->events--;
2449                 mddev->can_decrease_events = 0;
2450         } else {
2451                 /* otherwise we have to go forward and ... */
2452                 mddev->events ++;
2453                 mddev->can_decrease_events = nospares;
2454         }
2455 
2456         if (!mddev->events) {
2457                 /*
2458                  * oops, this 64-bit counter should never wrap.
2459                  * Either we are in around ~1 trillion A.C., assuming
2460                  * 1 reboot per second, or we have a bug:
2461                  */
2462                 MD_BUG();
2463                 mddev->events --;
2464         }
2465 
2466         rdev_for_each(rdev, mddev) {
2467                 if (rdev->badblocks.changed)
2468                         any_badblocks_changed++;
2469                 if (test_bit(Faulty, &rdev->flags))
2470                         set_bit(FaultRecorded, &rdev->flags);
2471         }
2472 
2473         sync_sbs(mddev, nospares);
2474         spin_unlock_irq(&mddev->write_lock);
2475 
2476         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2477                  mdname(mddev), mddev->in_sync);
2478 
2479         bitmap_update_sb(mddev->bitmap);
2480         rdev_for_each(rdev, mddev) {
2481                 char b[BDEVNAME_SIZE];
2482 
2483                 if (rdev->sb_loaded != 1)
2484                         continue; /* no noise on spare devices */
2485 
2486                 if (!test_bit(Faulty, &rdev->flags)) {
2487                         md_super_write(mddev,rdev,
2488                                        rdev->sb_start, rdev->sb_size,
2489                                        rdev->sb_page);
2490                         pr_debug("md: (write) %s's sb offset: %llu\n",
2491                                  bdevname(rdev->bdev, b),
2492                                  (unsigned long long)rdev->sb_start);
2493                         rdev->sb_events = mddev->events;
2494                         if (rdev->badblocks.size) {
2495                                 md_super_write(mddev, rdev,
2496                                                rdev->badblocks.sector,
2497                                                rdev->badblocks.size << 9,
2498                                                rdev->bb_page);
2499                                 rdev->badblocks.size = 0;
2500                         }
2501 
2502                 } else
2503                         pr_debug("md: %s (skipping faulty)\n",
2504                                  bdevname(rdev->bdev, b));
2505 
2506                 if (mddev->level == LEVEL_MULTIPATH)
2507                         /* only need to write one superblock... */
2508                         break;
2509         }
2510         md_super_wait(mddev);
2511         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2512 
2513         spin_lock_irq(&mddev->write_lock);
2514         if (mddev->in_sync != sync_req ||
2515             test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2516                 /* have to write it out again */
2517                 spin_unlock_irq(&mddev->write_lock);
2518                 goto repeat;
2519         }
2520         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2521         spin_unlock_irq(&mddev->write_lock);
2522         wake_up(&mddev->sb_wait);
2523         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2524                 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2525 
2526         rdev_for_each(rdev, mddev) {
2527                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2528                         clear_bit(Blocked, &rdev->flags);
2529 
2530                 if (any_badblocks_changed)
2531                         md_ack_all_badblocks(&rdev->badblocks);
2532                 clear_bit(BlockedBadBlocks, &rdev->flags);
2533                 wake_up(&rdev->blocked_wait);
2534         }
2535 }
2536 
2537 /* words written to sysfs files may, or may not, be \n terminated.
2538  * We want to accept with case. For this we use cmd_match.
2539  */
2540 static int cmd_match(const char *cmd, const char *str)
2541 {
2542         /* See if cmd, written into a sysfs file, matches
2543          * str.  They must either be the same, or cmd can
2544          * have a trailing newline
2545          */
2546         while (*cmd && *str && *cmd == *str) {
2547                 cmd++;
2548                 str++;
2549         }
2550         if (*cmd == '\n')
2551                 cmd++;
2552         if (*str || *cmd)
2553                 return 0;
2554         return 1;
2555 }
2556 
2557 struct rdev_sysfs_entry {
2558         struct attribute attr;
2559         ssize_t (*show)(struct md_rdev *, char *);
2560         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2561 };
2562 
2563 static ssize_t
2564 state_show(struct md_rdev *rdev, char *page)
2565 {
2566         char *sep = "";
2567         size_t len = 0;
2568 
2569         if (test_bit(Faulty, &rdev->flags) ||
2570             rdev->badblocks.unacked_exist) {
2571                 len+= sprintf(page+len, "%sfaulty",sep);
2572                 sep = ",";
2573         }
2574         if (test_bit(In_sync, &rdev->flags)) {
2575                 len += sprintf(page+len, "%sin_sync",sep);
2576                 sep = ",";
2577         }
2578         if (test_bit(WriteMostly, &rdev->flags)) {
2579                 len += sprintf(page+len, "%swrite_mostly",sep);
2580                 sep = ",";
2581         }
2582         if (test_bit(Blocked, &rdev->flags) ||
2583             (rdev->badblocks.unacked_exist
2584              && !test_bit(Faulty, &rdev->flags))) {
2585                 len += sprintf(page+len, "%sblocked", sep);
2586                 sep = ",";
2587         }
2588         if (!test_bit(Faulty, &rdev->flags) &&
2589             !test_bit(In_sync, &rdev->flags)) {
2590                 len += sprintf(page+len, "%sspare", sep);
2591                 sep = ",";
2592         }
2593         if (test_bit(WriteErrorSeen, &rdev->flags)) {
2594                 len += sprintf(page+len, "%swrite_error", sep);
2595                 sep = ",";
2596         }
2597         if (test_bit(WantReplacement, &rdev->flags)) {
2598                 len += sprintf(page+len, "%swant_replacement", sep);
2599                 sep = ",";
2600         }
2601         if (test_bit(Replacement, &rdev->flags)) {
2602                 len += sprintf(page+len, "%sreplacement", sep);
2603                 sep = ",";
2604         }
2605 
2606         return len+sprintf(page+len, "\n");
2607 }
2608 
2609 static ssize_t
2610 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2611 {
2612         /* can write
2613          *  faulty  - simulates an error
2614          *  remove  - disconnects the device
2615          *  writemostly - sets write_mostly
2616          *  -writemostly - clears write_mostly
2617          *  blocked - sets the Blocked flags
2618          *  -blocked - clears the Blocked and possibly simulates an error
2619          *  insync - sets Insync providing device isn't active
2620          *  -insync - clear Insync for a device with a slot assigned,
2621          *            so that it gets rebuilt based on bitmap
2622          *  write_error - sets WriteErrorSeen
2623          *  -write_error - clears WriteErrorSeen
2624          */
2625         int err = -EINVAL;
2626         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2627                 md_error(rdev->mddev, rdev);
2628                 if (test_bit(Faulty, &rdev->flags))
2629                         err = 0;
2630                 else
2631                         err = -EBUSY;
2632         } else if (cmd_match(buf, "remove")) {
2633                 if (rdev->raid_disk >= 0)
2634                         err = -EBUSY;
2635                 else {
2636                         struct mddev *mddev = rdev->mddev;
2637                         kick_rdev_from_array(rdev);
2638                         if (mddev->pers)
2639                                 md_update_sb(mddev, 1);
2640                         md_new_event(mddev);
2641                         err = 0;
2642                 }
2643         } else if (cmd_match(buf, "writemostly")) {
2644                 set_bit(WriteMostly, &rdev->flags);
2645                 err = 0;
2646         } else if (cmd_match(buf, "-writemostly")) {
2647                 clear_bit(WriteMostly, &rdev->flags);
2648                 err = 0;
2649         } else if (cmd_match(buf, "blocked")) {
2650                 set_bit(Blocked, &rdev->flags);
2651                 err = 0;
2652         } else if (cmd_match(buf, "-blocked")) {
2653                 if (!test_bit(Faulty, &rdev->flags) &&
2654                     rdev->badblocks.unacked_exist) {
2655                         /* metadata handler doesn't understand badblocks,
2656                          * so we need to fail the device
2657                          */
2658                         md_error(rdev->mddev, rdev);
2659                 }
2660                 clear_bit(Blocked, &rdev->flags);
2661                 clear_bit(BlockedBadBlocks, &rdev->flags);
2662                 wake_up(&rdev->blocked_wait);
2663                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2664                 md_wakeup_thread(rdev->mddev->thread);
2665 
2666                 err = 0;
2667         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2668                 set_bit(In_sync, &rdev->flags);
2669                 err = 0;
2670         } else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0) {
2671                 clear_bit(In_sync, &rdev->flags);
2672                 rdev->saved_raid_disk = rdev->raid_disk;
2673                 rdev->raid_disk = -1;
2674                 err = 0;
2675         } else if (cmd_match(buf, "write_error")) {
2676                 set_bit(WriteErrorSeen, &rdev->flags);
2677                 err = 0;
2678         } else if (cmd_match(buf, "-write_error")) {
2679                 clear_bit(WriteErrorSeen, &rdev->flags);
2680                 err = 0;
2681         } else if (cmd_match(buf, "want_replacement")) {
2682                 /* Any non-spare device that is not a replacement can
2683                  * become want_replacement at any time, but we then need to
2684                  * check if recovery is needed.
2685                  */
2686                 if (rdev->raid_disk >= 0 &&
2687                     !test_bit(Replacement, &rdev->flags))
2688                         set_bit(WantReplacement, &rdev->flags);
2689                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2690                 md_wakeup_thread(rdev->mddev->thread);
2691                 err = 0;
2692         } else if (cmd_match(buf, "-want_replacement")) {
2693                 /* Clearing 'want_replacement' is always allowed.
2694                  * Once replacements starts it is too late though.
2695                  */
2696                 err = 0;
2697                 clear_bit(WantReplacement, &rdev->flags);
2698         } else if (cmd_match(buf, "replacement")) {
2699                 /* Can only set a device as a replacement when array has not
2700                  * yet been started.  Once running, replacement is automatic
2701                  * from spares, or by assigning 'slot'.
2702                  */
2703                 if (rdev->mddev->pers)
2704                         err = -EBUSY;
2705                 else {
2706                         set_bit(Replacement, &rdev->flags);
2707                         err = 0;
2708                 }
2709         } else if (cmd_match(buf, "-replacement")) {
2710                 /* Similarly, can only clear Replacement before start */
2711                 if (rdev->mddev->pers)
2712                         err = -EBUSY;
2713                 else {
2714                         clear_bit(Replacement, &rdev->flags);
2715                         err = 0;
2716                 }
2717         }
2718         if (!err)
2719                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2720         return err ? err : len;
2721 }
2722 static struct rdev_sysfs_entry rdev_state =
2723 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2724 
2725 static ssize_t
2726 errors_show(struct md_rdev *rdev, char *page)
2727 {
2728         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2729 }
2730 
2731 static ssize_t
2732 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2733 {
2734         char *e;
2735         unsigned long n = simple_strtoul(buf, &e, 10);
2736         if (*buf && (*e == 0 || *e == '\n')) {
2737                 atomic_set(&rdev->corrected_errors, n);
2738                 return len;
2739         }
2740         return -EINVAL;
2741 }
2742 static struct rdev_sysfs_entry rdev_errors =
2743 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2744 
2745 static ssize_t
2746 slot_show(struct md_rdev *rdev, char *page)
2747 {
2748         if (rdev->raid_disk < 0)
2749                 return sprintf(page, "none\n");
2750         else
2751                 return sprintf(page, "%d\n", rdev->raid_disk);
2752 }
2753 
2754 static ssize_t
2755 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2756 {
2757         char *e;
2758         int err;
2759         int slot = simple_strtoul(buf, &e, 10);
2760         if (strncmp(buf, "none", 4)==0)
2761                 slot = -1;
2762         else if (e==buf || (*e && *e!= '\n'))
2763                 return -EINVAL;
2764         if (rdev->mddev->pers && slot == -1) {
2765                 /* Setting 'slot' on an active array requires also
2766                  * updating the 'rd%d' link, and communicating
2767                  * with the personality with ->hot_*_disk.
2768                  * For now we only support removing
2769                  * failed/spare devices.  This normally happens automatically,
2770                  * but not when the metadata is externally managed.
2771                  */
2772                 if (rdev->raid_disk == -1)
2773                         return -EEXIST;
2774                 /* personality does all needed checks */
2775                 if (rdev->mddev->pers->hot_remove_disk == NULL)
2776                         return -EINVAL;
2777                 clear_bit(Blocked, &rdev->flags);
2778                 remove_and_add_spares(rdev->mddev, rdev);
2779                 if (rdev->raid_disk >= 0)
2780                         return -EBUSY;
2781                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2782                 md_wakeup_thread(rdev->mddev->thread);
2783         } else if (rdev->mddev->pers) {
2784                 /* Activating a spare .. or possibly reactivating
2785                  * if we ever get bitmaps working here.
2786                  */
2787 
2788                 if (rdev->raid_disk != -1)
2789                         return -EBUSY;
2790 
2791                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2792                         return -EBUSY;
2793 
2794                 if (rdev->mddev->pers->hot_add_disk == NULL)
2795                         return -EINVAL;
2796 
2797                 if (slot >= rdev->mddev->raid_disks &&
2798                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2799                         return -ENOSPC;
2800 
2801                 rdev->raid_disk = slot;
2802                 if (test_bit(In_sync, &rdev->flags))
2803                         rdev->saved_raid_disk = slot;
2804                 else
2805                         rdev->saved_raid_disk = -1;
2806                 clear_bit(In_sync, &rdev->flags);
2807                 clear_bit(Bitmap_sync, &rdev->flags);
2808                 err = rdev->mddev->pers->
2809                         hot_add_disk(rdev->mddev, rdev);
2810                 if (err) {
2811                         rdev->raid_disk = -1;
2812                         return err;
2813                 } else
2814                         sysfs_notify_dirent_safe(rdev->sysfs_state);
2815                 if (sysfs_link_rdev(rdev->mddev, rdev))
2816                         /* failure here is OK */;
2817                 /* don't wakeup anyone, leave that to userspace. */
2818         } else {
2819                 if (slot >= rdev->mddev->raid_disks &&
2820                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2821                         return -ENOSPC;
2822                 rdev->raid_disk = slot;
2823                 /* assume it is working */
2824                 clear_bit(Faulty, &rdev->flags);
2825                 clear_bit(WriteMostly, &rdev->flags);
2826                 set_bit(In_sync, &rdev->flags);
2827                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2828         }
2829         return len;
2830 }
2831 
2832 
2833 static struct rdev_sysfs_entry rdev_slot =
2834 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2835 
2836 static ssize_t
2837 offset_show(struct md_rdev *rdev, char *page)
2838 {
2839         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2840 }
2841 
2842 static ssize_t
2843 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2844 {
2845         unsigned long long offset;
2846         if (kstrtoull(buf, 10, &offset) < 0)
2847                 return -EINVAL;
2848         if (rdev->mddev->pers && rdev->raid_disk >= 0)
2849                 return -EBUSY;
2850         if (rdev->sectors && rdev->mddev->external)
2851                 /* Must set offset before size, so overlap checks
2852                  * can be sane */
2853                 return -EBUSY;
2854         rdev->data_offset = offset;
2855         rdev->new_data_offset = offset;
2856         return len;
2857 }
2858 
2859 static struct rdev_sysfs_entry rdev_offset =
2860 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2861 
2862 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2863 {
2864         return sprintf(page, "%llu\n",
2865                        (unsigned long long)rdev->new_data_offset);
2866 }
2867 
2868 static ssize_t new_offset_store(struct md_rdev *rdev,
2869                                 const char *buf, size_t len)
2870 {
2871         unsigned long long new_offset;
2872         struct mddev *mddev = rdev->mddev;
2873 
2874         if (kstrtoull(buf, 10, &new_offset) < 0)
2875                 return -EINVAL;
2876 
2877         if (mddev->sync_thread)
2878                 return -EBUSY;
2879         if (new_offset == rdev->data_offset)
2880                 /* reset is always permitted */
2881                 ;
2882         else if (new_offset > rdev->data_offset) {
2883                 /* must not push array size beyond rdev_sectors */
2884                 if (new_offset - rdev->data_offset
2885                     + mddev->dev_sectors > rdev->sectors)
2886                                 return -E2BIG;
2887         }
2888         /* Metadata worries about other space details. */
2889 
2890         /* decreasing the offset is inconsistent with a backwards
2891          * reshape.
2892          */
2893         if (new_offset < rdev->data_offset &&
2894             mddev->reshape_backwards)
2895                 return -EINVAL;
2896         /* Increasing offset is inconsistent with forwards
2897          * reshape.  reshape_direction should be set to
2898          * 'backwards' first.
2899          */
2900         if (new_offset > rdev->data_offset &&
2901             !mddev->reshape_backwards)
2902                 return -EINVAL;
2903 
2904         if (mddev->pers && mddev->persistent &&
2905             !super_types[mddev->major_version]
2906             .allow_new_offset(rdev, new_offset))
2907                 return -E2BIG;
2908         rdev->new_data_offset = new_offset;
2909         if (new_offset > rdev->data_offset)
2910                 mddev->reshape_backwards = 1;
2911         else if (new_offset < rdev->data_offset)
2912                 mddev->reshape_backwards = 0;
2913 
2914         return len;
2915 }
2916 static struct rdev_sysfs_entry rdev_new_offset =
2917 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2918 
2919 static ssize_t
2920 rdev_size_show(struct md_rdev *rdev, char *page)
2921 {
2922         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2923 }
2924 
2925 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2926 {
2927         /* check if two start/length pairs overlap */
2928         if (s1+l1 <= s2)
2929                 return 0;
2930         if (s2+l2 <= s1)
2931                 return 0;
2932         return 1;
2933 }
2934 
2935 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2936 {
2937         unsigned long long blocks;
2938         sector_t new;
2939 
2940         if (kstrtoull(buf, 10, &blocks) < 0)
2941                 return -EINVAL;
2942 
2943         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2944                 return -EINVAL; /* sector conversion overflow */
2945 
2946         new = blocks * 2;
2947         if (new != blocks * 2)
2948                 return -EINVAL; /* unsigned long long to sector_t overflow */
2949 
2950         *sectors = new;
2951         return 0;
2952 }
2953 
2954 static ssize_t
2955 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2956 {
2957         struct mddev *my_mddev = rdev->mddev;
2958         sector_t oldsectors = rdev->sectors;
2959         sector_t sectors;
2960 
2961         if (strict_blocks_to_sectors(buf, &sectors) < 0)
2962                 return -EINVAL;
2963         if (rdev->data_offset != rdev->new_data_offset)
2964                 return -EINVAL; /* too confusing */
2965         if (my_mddev->pers && rdev->raid_disk >= 0) {
2966                 if (my_mddev->persistent) {
2967                         sectors = super_types[my_mddev->major_version].
2968                                 rdev_size_change(rdev, sectors);
2969                         if (!sectors)
2970                                 return -EBUSY;
2971                 } else if (!sectors)
2972                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2973                                 rdev->data_offset;
2974                 if (!my_mddev->pers->resize)
2975                         /* Cannot change size for RAID0 or Linear etc */
2976                         return -EINVAL;
2977         }
2978         if (sectors < my_mddev->dev_sectors)
2979                 return -EINVAL; /* component must fit device */
2980 
2981         rdev->sectors = sectors;
2982         if (sectors > oldsectors && my_mddev->external) {
2983                 /* need to check that all other rdevs with the same ->bdev
2984                  * do not overlap.  We need to unlock the mddev to avoid
2985                  * a deadlock.  We have already changed rdev->sectors, and if
2986                  * we have to change it back, we will have the lock again.
2987                  */
2988                 struct mddev *mddev;
2989                 int overlap = 0;
2990                 struct list_head *tmp;
2991 
2992                 mddev_unlock(my_mddev);
2993                 for_each_mddev(mddev, tmp) {
2994                         struct md_rdev *rdev2;
2995 
2996                         mddev_lock_nointr(mddev);
2997                         rdev_for_each(rdev2, mddev)
2998                                 if (rdev->bdev == rdev2->bdev &&
2999                                     rdev != rdev2 &&
3000                                     overlaps(rdev->data_offset, rdev->sectors,
3001                                              rdev2->data_offset,
3002                                              rdev2->sectors)) {
3003                                         overlap = 1;
3004                                         break;
3005                                 }
3006                         mddev_unlock(mddev);
3007                         if (overlap) {
3008                                 mddev_put(mddev);
3009                                 break;
3010                         }
3011                 }
3012                 mddev_lock_nointr(my_mddev);
3013                 if (overlap) {
3014                         /* Someone else could have slipped in a size
3015                          * change here, but doing so is just silly.
3016                          * We put oldsectors back because we *know* it is
3017                          * safe, and trust userspace not to race with
3018                          * itself
3019                          */
3020                         rdev->sectors = oldsectors;
3021                         return -EBUSY;
3022                 }
3023         }
3024         return len;
3025 }
3026 
3027 static struct rdev_sysfs_entry rdev_size =
3028 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3029 
3030 
3031 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3032 {
3033         unsigned long long recovery_start = rdev->recovery_offset;
3034 
3035         if (test_bit(In_sync, &rdev->flags) ||
3036             recovery_start == MaxSector)
3037                 return sprintf(page, "none\n");
3038 
3039         return sprintf(page, "%llu\n", recovery_start);
3040 }
3041 
3042 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3043 {
3044         unsigned long long recovery_start;
3045 
3046         if (cmd_match(buf, "none"))
3047                 recovery_start = MaxSector;
3048         else if (kstrtoull(buf, 10, &recovery_start))
3049                 return -EINVAL;
3050 
3051         if (rdev->mddev->pers &&
3052             rdev->raid_disk >= 0)
3053                 return -EBUSY;
3054 
3055         rdev->recovery_offset = recovery_start;
3056         if (recovery_start == MaxSector)
3057                 set_bit(In_sync, &rdev->flags);
3058         else
3059                 clear_bit(In_sync, &rdev->flags);
3060         return len;
3061 }
3062 
3063 static struct rdev_sysfs_entry rdev_recovery_start =
3064 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3065 
3066 
3067 static ssize_t
3068 badblocks_show(struct badblocks *bb, char *page, int unack);
3069 static ssize_t
3070 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
3071 
3072 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3073 {
3074         return badblocks_show(&rdev->badblocks, page, 0);
3075 }
3076 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3077 {
3078         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3079         /* Maybe that ack was all we needed */
3080         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3081                 wake_up(&rdev->blocked_wait);
3082         return rv;
3083 }
3084 static struct rdev_sysfs_entry rdev_bad_blocks =
3085 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3086 
3087 
3088 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3089 {
3090         return badblocks_show(&rdev->badblocks, page, 1);
3091 }
3092 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3093 {
3094         return badblocks_store(&rdev->badblocks, page, len, 1);
3095 }
3096 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3097 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3098 
3099 static struct attribute *rdev_default_attrs[] = {
3100         &rdev_state.attr,
3101         &rdev_errors.attr,
3102         &rdev_slot.attr,
3103         &rdev_offset.attr,
3104         &rdev_new_offset.attr,
3105         &rdev_size.attr,
3106         &rdev_recovery_start.attr,
3107         &rdev_bad_blocks.attr,
3108         &rdev_unack_bad_blocks.attr,
3109         NULL,
3110 };
3111 static ssize_t
3112 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3113 {
3114         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3115         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3116         struct mddev *mddev = rdev->mddev;
3117         ssize_t rv;
3118 
3119         if (!entry->show)
3120                 return -EIO;
3121 
3122         rv = mddev ? mddev_lock(mddev) : -EBUSY;
3123         if (!rv) {
3124                 if (rdev->mddev == NULL)
3125                         rv = -EBUSY;
3126                 else
3127                         rv = entry->show(rdev, page);
3128                 mddev_unlock(mddev);
3129         }
3130         return rv;
3131 }
3132 
3133 static ssize_t
3134 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3135               const char *page, size_t length)
3136 {
3137         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3138         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3139         ssize_t rv;
3140         struct mddev *mddev = rdev->mddev;
3141 
3142         if (!entry->store)
3143                 return -EIO;
3144         if (!capable(CAP_SYS_ADMIN))
3145                 return -EACCES;
3146         rv = mddev ? mddev_lock(mddev): -EBUSY;
3147         if (!rv) {
3148                 if (rdev->mddev == NULL)
3149                         rv = -EBUSY;
3150                 else
3151                         rv = entry->store(rdev, page, length);
3152                 mddev_unlock(mddev);
3153         }
3154         return rv;
3155 }
3156 
3157 static void rdev_free(struct kobject *ko)
3158 {
3159         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3160         kfree(rdev);
3161 }
3162 static const struct sysfs_ops rdev_sysfs_ops = {
3163         .show           = rdev_attr_show,
3164         .store          = rdev_attr_store,
3165 };
3166 static struct kobj_type rdev_ktype = {
3167         .release        = rdev_free,
3168         .sysfs_ops      = &rdev_sysfs_ops,
3169         .default_attrs  = rdev_default_attrs,
3170 };
3171 
3172 int md_rdev_init(struct md_rdev *rdev)
3173 {
3174         rdev->desc_nr = -1;
3175         rdev->saved_raid_disk = -1;
3176         rdev->raid_disk = -1;
3177         rdev->flags = 0;
3178         rdev->data_offset = 0;
3179         rdev->new_data_offset = 0;
3180         rdev->sb_events = 0;
3181         rdev->last_read_error.tv_sec  = 0;
3182         rdev->last_read_error.tv_nsec = 0;
3183         rdev->sb_loaded = 0;
3184         rdev->bb_page = NULL;
3185         atomic_set(&rdev->nr_pending, 0);
3186         atomic_set(&rdev->read_errors, 0);
3187         atomic_set(&rdev->corrected_errors, 0);
3188 
3189         INIT_LIST_HEAD(&rdev->same_set);
3190         init_waitqueue_head(&rdev->blocked_wait);
3191 
3192         /* Add space to store bad block list.
3193          * This reserves the space even on arrays where it cannot
3194          * be used - I wonder if that matters
3195          */
3196         rdev->badblocks.count = 0;
3197         rdev->badblocks.shift = -1; /* disabled until explicitly enabled */
3198         rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3199         seqlock_init(&rdev->badblocks.lock);
3200         if (rdev->badblocks.page == NULL)
3201                 return -ENOMEM;
3202 
3203         return 0;
3204 }
3205 EXPORT_SYMBOL_GPL(md_rdev_init);
3206 /*
3207  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3208  *
3209  * mark the device faulty if:
3210  *
3211  *   - the device is nonexistent (zero size)
3212  *   - the device has no valid superblock
3213  *
3214  * a faulty rdev _never_ has rdev->sb set.
3215  */
3216 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3217 {
3218         char b[BDEVNAME_SIZE];
3219         int err;
3220         struct md_rdev *rdev;
3221         sector_t size;
3222 
3223         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3224         if (!rdev) {
3225                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
3226                 return ERR_PTR(-ENOMEM);
3227         }
3228 
3229         err = md_rdev_init(rdev);
3230         if (err)
3231                 goto abort_free;
3232         err = alloc_disk_sb(rdev);
3233         if (err)
3234                 goto abort_free;
3235 
3236         err = lock_rdev(rdev, newdev, super_format == -2);
3237         if (err)
3238                 goto abort_free;
3239 
3240         kobject_init(&rdev->kobj, &rdev_ktype);
3241 
3242         size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3243         if (!size) {
3244                 printk(KERN_WARNING 
3245                         "md: %s has zero or unknown size, marking faulty!\n",
3246                         bdevname(rdev->bdev,b));
3247                 err = -EINVAL;
3248                 goto abort_free;
3249         }
3250 
3251         if (super_format >= 0) {
3252                 err = super_types[super_format].
3253                         load_super(rdev, NULL, super_minor);
3254                 if (err == -EINVAL) {
3255                         printk(KERN_WARNING
3256                                 "md: %s does not have a valid v%d.%d "
3257                                "superblock, not importing!\n",
3258                                 bdevname(rdev->bdev,b),
3259                                super_format, super_minor);
3260                         goto abort_free;
3261                 }
3262                 if (err < 0) {
3263                         printk(KERN_WARNING 
3264                                 "md: could not read %s's sb, not importing!\n",
3265                                 bdevname(rdev->bdev,b));
3266                         goto abort_free;
3267                 }
3268         }
3269 
3270         return rdev;
3271 
3272 abort_free:
3273         if (rdev->bdev)
3274                 unlock_rdev(rdev);
3275         md_rdev_clear(rdev);
3276         kfree(rdev);
3277         return ERR_PTR(err);
3278 }
3279 
3280 /*
3281  * Check a full RAID array for plausibility
3282  */
3283 
3284 
3285 static void analyze_sbs(struct mddev * mddev)
3286 {
3287         int i;
3288         struct md_rdev *rdev, *freshest, *tmp;
3289         char b[BDEVNAME_SIZE];
3290 
3291         freshest = NULL;
3292         rdev_for_each_safe(rdev, tmp, mddev)
3293                 switch (super_types[mddev->major_version].
3294                         load_super(rdev, freshest, mddev->minor_version)) {
3295                 case 1:
3296                         freshest = rdev;
3297                         break;
3298                 case 0:
3299                         break;
3300                 default:
3301                         printk( KERN_ERR \
3302                                 "md: fatal superblock inconsistency in %s"
3303                                 " -- removing from array\n", 
3304                                 bdevname(rdev->bdev,b));
3305                         kick_rdev_from_array(rdev);
3306                 }
3307 
3308 
3309         super_types[mddev->major_version].
3310                 validate_super(mddev, freshest);
3311 
3312         i = 0;
3313         rdev_for_each_safe(rdev, tmp, mddev) {
3314                 if (mddev->max_disks &&
3315                     (rdev->desc_nr >= mddev->max_disks ||
3316                      i > mddev->max_disks)) {
3317                         printk(KERN_WARNING
3318                                "md: %s: %s: only %d devices permitted\n",
3319                                mdname(mddev), bdevname(rdev->bdev, b),
3320                                mddev->max_disks);
3321                         kick_rdev_from_array(rdev);
3322                         continue;
3323                 }
3324                 if (rdev != freshest)
3325                         if (super_types[mddev->major_version].
3326                             validate_super(mddev, rdev)) {
3327                                 printk(KERN_WARNING "md: kicking non-fresh %s"
3328                                         " from array!\n",
3329                                         bdevname(rdev->bdev,b));
3330                                 kick_rdev_from_array(rdev);
3331                                 continue;
3332                         }
3333                 if (mddev->level == LEVEL_MULTIPATH) {
3334                         rdev->desc_nr = i++;
3335                         rdev->raid_disk = rdev->desc_nr;
3336                         set_bit(In_sync, &rdev->flags);
3337                 } else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3338                         rdev->raid_disk = -1;
3339                         clear_bit(In_sync, &rdev->flags);
3340                 }
3341         }
3342 }
3343 
3344 /* Read a fixed-point number.
3345  * Numbers in sysfs attributes should be in "standard" units where
3346  * possible, so time should be in seconds.
3347  * However we internally use a a much smaller unit such as 
3348  * milliseconds or jiffies.
3349  * This function takes a decimal number with a possible fractional
3350  * component, and produces an integer which is the result of
3351  * multiplying that number by 10^'scale'.
3352  * all without any floating-point arithmetic.
3353  */
3354 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3355 {
3356         unsigned long result = 0;
3357         long decimals = -1;
3358         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3359                 if (*cp == '.')
3360                         decimals = 0;
3361                 else if (decimals < scale) {
3362                         unsigned int value;
3363                         value = *cp - '';
3364                         result = result * 10 + value;
3365                         if (decimals >= 0)
3366                                 decimals++;
3367                 }
3368                 cp++;
3369         }
3370         if (*cp == '\n')
3371                 cp++;
3372         if (*cp)
3373                 return -EINVAL;
3374         if (decimals < 0)
3375                 decimals = 0;
3376         while (decimals < scale) {
3377                 result *= 10;
3378                 decimals ++;
3379         }
3380         *res = result;
3381         return 0;
3382 }
3383 
3384 
3385 static void md_safemode_timeout(unsigned long data);
3386 
3387 static ssize_t
3388 safe_delay_show(struct mddev *mddev, char *page)
3389 {
3390         int msec = (mddev->safemode_delay*1000)/HZ;
3391         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3392 }
3393 static ssize_t
3394 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3395 {
3396         unsigned long msec;
3397 
3398         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3399                 return -EINVAL;
3400         if (msec == 0)
3401                 mddev->safemode_delay = 0;
3402         else {
3403                 unsigned long old_delay = mddev->safemode_delay;
3404                 mddev->safemode_delay = (msec*HZ)/1000;
3405                 if (mddev->safemode_delay == 0)
3406                         mddev->safemode_delay = 1;
3407                 if (mddev->safemode_delay < old_delay || old_delay == 0)
3408                         md_safemode_timeout((unsigned long)mddev);
3409         }
3410         return len;
3411 }
3412 static struct md_sysfs_entry md_safe_delay =
3413 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3414 
3415 static ssize_t
3416 level_show(struct mddev *mddev, char *page)
3417 {
3418         struct md_personality *p = mddev->pers;
3419         if (p)
3420                 return sprintf(page, "%s\n", p->name);
3421         else if (mddev->clevel[0])
3422                 return sprintf(page, "%s\n", mddev->clevel);
3423         else if (mddev->level != LEVEL_NONE)
3424                 return sprintf(page, "%d\n", mddev->level);
3425         else
3426                 return 0;
3427 }
3428 
3429 static ssize_t
3430 level_store(struct mddev *mddev, const char *buf, size_t len)
3431 {
3432         char clevel[16];
3433         ssize_t rv = len;
3434         struct md_personality *pers;
3435         long level;
3436         void *priv;
3437         struct md_rdev *rdev;
3438 
3439         if (mddev->pers == NULL) {
3440                 if (len == 0)
3441                         return 0;
3442                 if (len >= sizeof(mddev->clevel))
3443                         return -ENOSPC;
3444                 strncpy(mddev->clevel, buf, len);
3445                 if (mddev->clevel[len-1] == '\n')
3446                         len--;
3447                 mddev->clevel[len] = 0;
3448                 mddev->level = LEVEL_NONE;
3449                 return rv;
3450         }
3451         if (mddev->ro)
3452                 return  -EROFS;
3453 
3454         /* request to change the personality.  Need to ensure:
3455          *  - array is not engaged in resync/recovery/reshape
3456          *  - old personality can be suspended
3457          *  - new personality will access other array.
3458          */
3459 
3460         if (mddev->sync_thread ||
3461             mddev->reshape_position != MaxSector ||
3462             mddev->sysfs_active)
3463                 return -EBUSY;
3464 
3465         if (!mddev->pers->quiesce) {
3466                 printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3467                        mdname(mddev), mddev->pers->name);
3468                 return -EINVAL;
3469         }
3470 
3471         /* Now find the new personality */
3472         if (len == 0 || len >= sizeof(clevel))
3473                 return -EINVAL;
3474         strncpy(clevel, buf, len);
3475         if (clevel[len-1] == '\n')
3476                 len--;
3477         clevel[len] = 0;
3478         if (kstrtol(clevel, 10, &level))
3479                 level = LEVEL_NONE;
3480 
3481         if (request_module("md-%s", clevel) != 0)
3482                 request_module("md-level-%s", clevel);
3483         spin_lock(&pers_lock);
3484         pers = find_pers(level, clevel);
3485         if (!pers || !try_module_get(pers->owner)) {
3486                 spin_unlock(&pers_lock);
3487                 printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3488                 return -EINVAL;
3489         }
3490         spin_unlock(&pers_lock);
3491 
3492         if (pers == mddev->pers) {
3493                 /* Nothing to do! */
3494                 module_put(pers->owner);
3495                 return rv;
3496         }
3497         if (!pers->takeover) {
3498                 module_put(pers->owner);
3499                 printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3500                        mdname(mddev), clevel);
3501                 return -EINVAL;
3502         }
3503 
3504         rdev_for_each(rdev, mddev)
3505                 rdev->new_raid_disk = rdev->raid_disk;
3506 
3507         /* ->takeover must set new_* and/or delta_disks
3508          * if it succeeds, and may set them when it fails.
3509          */
3510         priv = pers->takeover(mddev);
3511         if (IS_ERR(priv)) {
3512                 mddev->new_level = mddev->level;
3513                 mddev->new_layout = mddev->layout;
3514                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3515                 mddev->raid_disks -= mddev->delta_disks;
3516                 mddev->delta_disks = 0;
3517                 mddev->reshape_backwards = 0;
3518                 module_put(pers->owner);
3519                 printk(KERN_WARNING "md: %s: %s would not accept array\n",
3520                        mdname(mddev), clevel);
3521                 return PTR_ERR(priv);
3522         }
3523 
3524         /* Looks like we have a winner */
3525         mddev_suspend(mddev);
3526         mddev->pers->stop(mddev);
3527         
3528         if (mddev->pers->sync_request == NULL &&
3529             pers->sync_request != NULL) {
3530                 /* need to add the md_redundancy_group */
3531                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3532                         printk(KERN_WARNING
3533                                "md: cannot register extra attributes for %s\n",
3534                                mdname(mddev));
3535                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3536         }               
3537         if (mddev->pers->sync_request != NULL &&
3538             pers->sync_request == NULL) {
3539                 /* need to remove the md_redundancy_group */
3540                 if (mddev->to_remove == NULL)
3541                         mddev->to_remove = &md_redundancy_group;
3542         }
3543 
3544         if (mddev->pers->sync_request == NULL &&
3545             mddev->external) {
3546                 /* We are converting from a no-redundancy array
3547                  * to a redundancy array and metadata is managed
3548                  * externally so we need to be sure that writes
3549                  * won't block due to a need to transition
3550                  *      clean->dirty
3551                  * until external management is started.
3552                  */
3553                 mddev->in_sync = 0;
3554                 mddev->safemode_delay = 0;
3555                 mddev->safemode = 0;
3556         }
3557 
3558         rdev_for_each(rdev, mddev) {
3559                 if (rdev->raid_disk < 0)
3560                         continue;
3561                 if (rdev->new_raid_disk >= mddev->raid_disks)
3562                         rdev->new_raid_disk = -1;
3563                 if (rdev->new_raid_disk == rdev->raid_disk)
3564                         continue;
3565                 sysfs_unlink_rdev(mddev, rdev);
3566         }
3567         rdev_for_each(rdev, mddev) {
3568                 if (rdev->raid_disk < 0)
3569                         continue;
3570                 if (rdev->new_raid_disk == rdev->raid_disk)
3571                         continue;
3572                 rdev->raid_disk = rdev->new_raid_disk;
3573                 if (rdev->raid_disk < 0)
3574                         clear_bit(In_sync, &rdev->flags);
3575                 else {
3576                         if (sysfs_link_rdev(mddev, rdev))
3577                                 printk(KERN_WARNING "md: cannot register rd%d"
3578                                        " for %s after level change\n",
3579                                        rdev->raid_disk, mdname(mddev));
3580                 }
3581         }
3582 
3583         module_put(mddev->pers->owner);
3584         mddev->pers = pers;
3585         mddev->private = priv;
3586         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3587         mddev->level = mddev->new_level;
3588         mddev->layout = mddev->new_layout;
3589         mddev->chunk_sectors = mddev->new_chunk_sectors;
3590         mddev->delta_disks = 0;
3591         mddev->reshape_backwards = 0;
3592         mddev->degraded = 0;
3593         if (mddev->pers->sync_request == NULL) {
3594                 /* this is now an array without redundancy, so
3595                  * it must always be in_sync
3596                  */
3597                 mddev->in_sync = 1;
3598                 del_timer_sync(&mddev->safemode_timer);
3599         }
3600         blk_set_stacking_limits(&mddev->queue->limits);
3601         pers->run(mddev);
3602         set_bit(MD_CHANGE_DEVS, &mddev->flags);
3603         mddev_resume(mddev);
3604         if (!mddev->thread)
3605                 md_update_sb(mddev, 1);
3606         sysfs_notify(&mddev->kobj, NULL, "level");
3607         md_new_event(mddev);
3608         return rv;
3609 }
3610 
3611 static struct md_sysfs_entry md_level =
3612 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3613 
3614 
3615 static ssize_t
3616 layout_show(struct mddev *mddev, char *page)
3617 {
3618         /* just a number, not meaningful for all levels */
3619         if (mddev->reshape_position != MaxSector &&
3620             mddev->layout != mddev->new_layout)
3621                 return sprintf(page, "%d (%d)\n",
3622                                mddev->new_layout, mddev->layout);
3623         return sprintf(page, "%d\n", mddev->layout);
3624 }
3625 
3626 static ssize_t
3627 layout_store(struct mddev *mddev, const char *buf, size_t len)
3628 {
3629         char *e;
3630         unsigned long n = simple_strtoul(buf, &e, 10);
3631 
3632         if (!*buf || (*e && *e != '\n'))
3633                 return -EINVAL;
3634 
3635         if (mddev->pers) {
3636                 int err;
3637                 if (mddev->pers->check_reshape == NULL)
3638                         return -EBUSY;
3639                 if (mddev->ro)
3640                         return -EROFS;
3641                 mddev->new_layout = n;
3642                 err = mddev->pers->check_reshape(mddev);
3643                 if (err) {
3644                         mddev->new_layout = mddev->layout;
3645                         return err;
3646                 }
3647         } else {
3648                 mddev->new_layout = n;
3649                 if (mddev->reshape_position == MaxSector)
3650                         mddev->layout = n;
3651         }
3652         return len;
3653 }
3654 static struct md_sysfs_entry md_layout =
3655 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3656 
3657 
3658 static ssize_t
3659 raid_disks_show(struct mddev *mddev, char *page)
3660 {
3661         if (mddev->raid_disks == 0)
3662                 return 0;
3663         if (mddev->reshape_position != MaxSector &&
3664             mddev->delta_disks != 0)
3665                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3666                                mddev->raid_disks - mddev->delta_disks);
3667         return sprintf(page, "%d\n", mddev->raid_disks);
3668 }
3669 
3670 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3671 
3672 static ssize_t
3673 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3674 {
3675         char *e;
3676         int rv = 0;
3677         unsigned long n = simple_strtoul(buf, &e, 10);
3678 
3679         if (!*buf || (*e && *e != '\n'))
3680                 return -EINVAL;
3681 
3682         if (mddev->pers)
3683                 rv = update_raid_disks(mddev, n);
3684         else if (mddev->reshape_position != MaxSector) {
3685                 struct md_rdev *rdev;
3686                 int olddisks = mddev->raid_disks - mddev->delta_disks;
3687 
3688                 rdev_for_each(rdev, mddev) {
3689                         if (olddisks < n &&
3690                             rdev->data_offset < rdev->new_data_offset)
3691                                 return -EINVAL;
3692                         if (olddisks > n &&
3693                             rdev->data_offset > rdev->new_data_offset)
3694                                 return -EINVAL;
3695                 }
3696                 mddev->delta_disks = n - olddisks;
3697                 mddev->raid_disks = n;
3698                 mddev->reshape_backwards = (mddev->delta_disks < 0);
3699         } else
3700                 mddev->raid_disks = n;
3701         return rv ? rv : len;
3702 }
3703 static struct md_sysfs_entry md_raid_disks =
3704 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3705 
3706 static ssize_t
3707 chunk_size_show(struct mddev *mddev, char *page)
3708 {
3709         if (mddev->reshape_position != MaxSector &&
3710             mddev->chunk_sectors != mddev->new_chunk_sectors)
3711                 return sprintf(page, "%d (%d)\n",
3712                                mddev->new_chunk_sectors << 9,
3713                                mddev->chunk_sectors << 9);
3714         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3715 }
3716 
3717 static ssize_t
3718 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3719 {
3720         char *e;
3721         unsigned long n = simple_strtoul(buf, &e, 10);
3722 
3723         if (!*buf || (*e && *e != '\n'))
3724                 return -EINVAL;
3725 
3726         if (mddev->pers) {
3727                 int err;
3728                 if (mddev->pers->check_reshape == NULL)
3729                         return -EBUSY;
3730                 if (mddev->ro)
3731                         return -EROFS;
3732                 mddev->new_chunk_sectors = n >> 9;
3733                 err = mddev->pers->check_reshape(mddev);
3734                 if (err) {
3735                         mddev->new_chunk_sectors = mddev->chunk_sectors;
3736                         return err;
3737                 }
3738         } else {
3739                 mddev->new_chunk_sectors = n >> 9;
3740                 if (mddev->reshape_position == MaxSector)
3741                         mddev->chunk_sectors = n >> 9;
3742         }
3743         return len;
3744 }
3745 static struct md_sysfs_entry md_chunk_size =
3746 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3747 
3748 static ssize_t
3749 resync_start_show(struct mddev *mddev, char *page)
3750 {
3751         if (mddev->recovery_cp == MaxSector)
3752                 return sprintf(page, "none\n");
3753         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3754 }
3755 
3756 static ssize_t
3757 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3758 {
3759         char *e;
3760         unsigned long long n = simple_strtoull(buf, &e, 10);
3761 
3762         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3763                 return -EBUSY;
3764         if (cmd_match(buf, "none"))
3765                 n = MaxSector;
3766         else if (!*buf || (*e && *e != '\n'))
3767                 return -EINVAL;
3768 
3769         mddev->recovery_cp = n;
3770         if (mddev->pers)
3771                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3772         return len;
3773 }
3774 static struct md_sysfs_entry md_resync_start =
3775 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3776 
3777 /*
3778  * The array state can be:
3779  *
3780  * clear
3781  *     No devices, no size, no level
3782  *     Equivalent to STOP_ARRAY ioctl
3783  * inactive
3784  *     May have some settings, but array is not active
3785  *        all IO results in error
3786  *     When written, doesn't tear down array, but just stops it
3787  * suspended (not supported yet)
3788  *     All IO requests will block. The array can be reconfigured.
3789  *     Writing this, if accepted, will block until array is quiescent
3790  * readonly
3791  *     no resync can happen.  no superblocks get written.
3792  *     write requests fail
3793  * read-auto
3794  *     like readonly, but behaves like 'clean' on a write request.
3795  *
3796  * clean - no pending writes, but otherwise active.
3797  *     When written to inactive array, starts without resync
3798  *     If a write request arrives then
3799  *       if metadata is known, mark 'dirty' and switch to 'active'.
3800  *       if not known, block and switch to write-pending
3801  *     If written to an active array that has pending writes, then fails.
3802  * active
3803  *     fully active: IO and resync can be happening.
3804  *     When written to inactive array, starts with resync
3805  *
3806  * write-pending
3807  *     clean, but writes are blocked waiting for 'active' to be written.
3808  *
3809  * active-idle
3810  *     like active, but no writes have been seen for a while (100msec).
3811  *
3812  */
3813 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3814                    write_pending, active_idle, bad_word};
3815 static char *array_states[] = {
3816         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3817         "write-pending", "active-idle", NULL };
3818 
3819 static int match_word(const char *word, char **list)
3820 {
3821         int n;
3822         for (n=0; list[n]; n++)
3823                 if (cmd_match(word, list[n]))
3824                         break;
3825         return n;
3826 }
3827 
3828 static ssize_t
3829 array_state_show(struct mddev *mddev, char *page)
3830 {
3831         enum array_state st = inactive;
3832 
3833         if (mddev->pers)
3834                 switch(mddev->ro) {
3835                 case 1:
3836                         st = readonly;
3837                         break;
3838                 case 2:
3839                         st = read_auto;
3840                         break;
3841                 case 0:
3842                         if (mddev->in_sync)
3843                                 st = clean;
3844                         else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3845                                 st = write_pending;
3846                         else if (mddev->safemode)
3847                                 st = active_idle;
3848                         else
3849                                 st = active;
3850                 }
3851         else {
3852                 if (list_empty(&mddev->disks) &&
3853                     mddev->raid_disks == 0 &&
3854                     mddev->dev_sectors == 0)
3855                         st = clear;
3856                 else
3857                         st = inactive;
3858         }
3859         return sprintf(page, "%s\n", array_states[st]);
3860 }
3861 
3862 static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
3863 static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
3864 static int do_md_run(struct mddev * mddev);
3865 static int restart_array(struct mddev *mddev);
3866 
3867 static ssize_t
3868 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3869 {
3870         int err = -EINVAL;
3871         enum array_state st = match_word(buf, array_states);
3872         switch(st) {
3873         case bad_word:
3874                 break;
3875         case clear:
3876                 /* stopping an active array */
3877                 err = do_md_stop(mddev, 0, NULL);
3878                 break;
3879         case inactive:
3880                 /* stopping an active array */
3881                 if (mddev->pers)
3882                         err = do_md_stop(mddev, 2, NULL);
3883                 else
3884                         err = 0; /* already inactive */
3885                 break;
3886         case suspended:
3887                 break; /* not supported yet */
3888         case readonly:
3889                 if (mddev->pers)
3890                         err = md_set_readonly(mddev, NULL);
3891                 else {
3892                         mddev->ro = 1;
3893                         set_disk_ro(mddev->gendisk, 1);
3894                         err = do_md_run(mddev);
3895                 }
3896                 break;
3897         case read_auto:
3898                 if (mddev->pers) {
3899                         if (mddev->ro == 0)
3900                                 err = md_set_readonly(mddev, NULL);
3901                         else if (mddev->ro == 1)
3902                                 err = restart_array(mddev);
3903                         if (err == 0) {
3904                                 mddev->ro = 2;
3905                                 set_disk_ro(mddev->gendisk, 0);
3906                         }
3907                 } else {
3908                         mddev->ro = 2;
3909                         err = do_md_run(mddev);
3910                 }
3911                 break;
3912         case clean:
3913                 if (mddev->pers) {
3914                         restart_array(mddev);
3915                         spin_lock_irq(&mddev->write_lock);
3916                         if (atomic_read(&mddev->writes_pending) == 0) {
3917                                 if (mddev->in_sync == 0) {
3918                                         mddev->in_sync = 1;
3919                                         if (mddev->safemode == 1)
3920                                                 mddev->safemode = 0;
3921                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3922                                 }
3923                                 err = 0;
3924                         } else
3925                                 err = -EBUSY;
3926                         spin_unlock_irq(&mddev->write_lock);
3927                 } else
3928                         err = -EINVAL;
3929                 break;
3930         case active:
3931                 if (mddev->pers) {
3932                         restart_array(mddev);
3933                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3934                         wake_up(&mddev->sb_wait);
3935                         err = 0;
3936                 } else {
3937                         mddev->ro = 0;
3938                         set_disk_ro(mddev->gendisk, 0);
3939                         err = do_md_run(mddev);
3940                 }
3941                 break;
3942         case write_pending:
3943         case active_idle:
3944                 /* these cannot be set */
3945                 break;
3946         }
3947         if (err)
3948                 return err;
3949         else {
3950                 if (mddev->hold_active == UNTIL_IOCTL)
3951                         mddev->hold_active = 0;
3952                 sysfs_notify_dirent_safe(mddev->sysfs_state);
3953                 return len;
3954         }
3955 }
3956 static struct md_sysfs_entry md_array_state =
3957 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3958 
3959 static ssize_t
3960 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
3961         return sprintf(page, "%d\n",
3962                        atomic_read(&mddev->max_corr_read_errors));
3963 }
3964 
3965 static ssize_t
3966 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
3967 {
3968         char *e;
3969         unsigned long n = simple_strtoul(buf, &e, 10);
3970 
3971         if (*buf && (*e == 0 || *e == '\n')) {
3972                 atomic_set(&mddev->max_corr_read_errors, n);
3973                 return len;
3974         }
3975         return -EINVAL;
3976 }
3977 
3978 static struct md_sysfs_entry max_corr_read_errors =
3979 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3980         max_corrected_read_errors_store);
3981 
3982 static ssize_t
3983 null_show(struct mddev *mddev, char *page)
3984 {
3985         return -EINVAL;
3986 }
3987 
3988 static ssize_t
3989 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
3990 {
3991         /* buf must be %d:%d\n? giving major and minor numbers */
3992         /* The new device is added to the array.
3993          * If the array has a persistent superblock, we read the
3994          * superblock to initialise info and check validity.
3995          * Otherwise, only checking done is that in bind_rdev_to_array,
3996          * which mainly checks size.
3997          */
3998         char *e;
3999         int major = simple_strtoul(buf, &e, 10);
4000         int minor;
4001         dev_t dev;
4002         struct md_rdev *rdev;
4003         int err;
4004 
4005         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4006                 return -EINVAL;
4007         minor = simple_strtoul(e+1, &e, 10);
4008         if (*e && *e != '\n')
4009                 return -EINVAL;
4010         dev = MKDEV(major, minor);
4011         if (major != MAJOR(dev) ||
4012             minor != MINOR(dev))
4013                 return -EOVERFLOW;
4014 
4015 
4016         if (mddev->persistent) {
4017                 rdev = md_import_device(dev, mddev->major_version,
4018                                         mddev->minor_version);
4019                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4020                         struct md_rdev *rdev0
4021                                 = list_entry(mddev->disks.next,
4022                                              struct md_rdev, same_set);
4023                         err = super_types[mddev->major_version]
4024                                 .load_super(rdev, rdev0, mddev->minor_version);
4025                         if (err < 0)
4026                                 goto out;
4027                 }
4028         } else if (mddev->external)
4029                 rdev = md_import_device(dev, -2, -1);
4030         else
4031                 rdev = md_import_device(dev, -1, -1);
4032 
4033         if (IS_ERR(rdev))
4034                 return PTR_ERR(rdev);
4035         err = bind_rdev_to_array(rdev, mddev);
4036  out:
4037         if (err)
4038                 export_rdev(rdev);
4039         return err ? err : len;
4040 }
4041 
4042 static struct md_sysfs_entry md_new_device =
4043 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4044 
4045 static ssize_t
4046 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4047 {
4048         char *end;
4049         unsigned long chunk, end_chunk;
4050 
4051         if (!mddev->bitmap)
4052                 goto out;
4053         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4054         while (*buf) {
4055                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4056                 if (buf == end) break;
4057                 if (*end == '-') { /* range */
4058                         buf = end + 1;
4059                         end_chunk = simple_strtoul(buf, &end, 0);
4060                         if (buf == end) break;
4061                 }
4062                 if (*end && !isspace(*end)) break;
4063                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4064                 buf = skip_spaces(end);
4065         }
4066         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4067 out:
4068         return len;
4069 }
4070 
4071 static struct md_sysfs_entry md_bitmap =
4072 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4073 
4074 static ssize_t
4075 size_show(struct mddev *mddev, char *page)
4076 {
4077         return sprintf(page, "%llu\n",
4078                 (unsigned long long)mddev->dev_sectors / 2);
4079 }
4080 
4081 static int update_size(struct mddev *mddev, sector_t num_sectors);
4082 
4083 static ssize_t
4084 size_store(struct mddev *mddev, const char *buf, size_t len)
4085 {
4086         /* If array is inactive, we can reduce the component size, but
4087          * not increase it (except from 0).
4088          * If array is active, we can try an on-line resize
4089          */
4090         sector_t sectors;
4091         int err = strict_blocks_to_sectors(buf, &sectors);
4092 
4093         if (err < 0)
4094                 return err;
4095         if (mddev->pers) {
4096                 err = update_size(mddev, sectors);
4097                 md_update_sb(mddev, 1);
4098         } else {
4099                 if (mddev->dev_sectors == 0 ||
4100                     mddev->dev_sectors > sectors)
4101                         mddev->dev_sectors = sectors;
4102                 else
4103                         err = -ENOSPC;
4104         }
4105         return err ? err : len;
4106 }
4107 
4108 static struct md_sysfs_entry md_size =
4109 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4110 
4111 
4112 /* Metadata version.
4113  * This is one of
4114  *   'none' for arrays with no metadata (good luck...)
4115  *   'external' for arrays with externally managed metadata,
4116  * or N.M for internally known formats
4117  */
4118 static ssize_t
4119 metadata_show(struct mddev *mddev, char *page)
4120 {
4121         if (mddev->persistent)
4122                 return sprintf(page, "%d.%d\n",
4123                                mddev->major_version, mddev->minor_version);
4124         else if (mddev->external)
4125                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4126         else
4127                 return sprintf(page, "none\n");
4128 }
4129 
4130 static ssize_t
4131 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4132 {
4133         int major, minor;
4134         char *e;
4135         /* Changing the details of 'external' metadata is
4136          * always permitted.  Otherwise there must be
4137          * no devices attached to the array.
4138          */
4139         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4140                 ;
4141         else if (!list_empty(&mddev->disks))
4142                 return -EBUSY;
4143 
4144         if (cmd_match(buf, "none")) {
4145                 mddev->persistent = 0;
4146                 mddev->external = 0;
4147                 mddev->major_version = 0;
4148                 mddev->minor_version = 90;
4149                 return len;
4150         }
4151         if (strncmp(buf, "external:", 9) == 0) {
4152                 size_t namelen = len-9;
4153                 if (namelen >= sizeof(mddev->metadata_type))
4154                         namelen = sizeof(mddev->metadata_type)-1;
4155                 strncpy(mddev->metadata_type, buf+9, namelen);
4156                 mddev->metadata_type[namelen] = 0;
4157                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4158                         mddev->metadata_type[--namelen] = 0;
4159                 mddev->persistent = 0;
4160                 mddev->external = 1;
4161                 mddev->major_version = 0;
4162                 mddev->minor_version = 90;
4163                 return len;
4164         }
4165         major = simple_strtoul(buf, &e, 10);
4166         if (e==buf || *e != '.')
4167                 return -EINVAL;
4168         buf = e+1;
4169         minor = simple_strtoul(buf, &e, 10);
4170         if (e==buf || (*e && *e != '\n') )
4171                 return -EINVAL;
4172         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4173                 return -ENOENT;
4174         mddev->major_version = major;
4175         mddev->minor_version = minor;
4176         mddev->persistent = 1;
4177         mddev->external = 0;
4178         return len;
4179 }
4180 
4181 static struct md_sysfs_entry md_metadata =
4182 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4183 
4184 static ssize_t
4185 action_show(struct mddev *mddev, char *page)
4186 {
4187         char *type = "idle";
4188         if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4189                 type = "frozen";
4190         else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4191             (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4192                 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4193                         type = "reshape";
4194                 else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4195                         if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4196                                 type = "resync";
4197                         else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4198                                 type = "check";
4199                         else
4200                                 type = "repair";
4201                 } else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4202                         type = "recover";
4203         }
4204         return sprintf(page, "%s\n", type);
4205 }
4206 
4207 static ssize_t
4208 action_store(struct mddev *mddev, const char *page, size_t len)
4209 {
4210         if (!mddev->pers || !mddev->pers->sync_request)
4211                 return -EINVAL;
4212 
4213         if (cmd_match(page, "frozen"))
4214                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4215         else
4216                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4217 
4218         if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4219                 if (mddev->sync_thread) {
4220                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4221                         md_reap_sync_thread(mddev);
4222                 }
4223         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4224                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4225                 return -EBUSY;
4226         else if (cmd_match(page, "resync"))
4227                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4228         else if (cmd_match(page, "recover")) {
4229                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4230                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4231         } else if (cmd_match(page, "reshape")) {
4232                 int err;
4233                 if (mddev->pers->start_reshape == NULL)
4234                         return -EINVAL;
4235                 err = mddev->pers->start_reshape(mddev);
4236                 if (err)
4237                         return err;
4238                 sysfs_notify(&mddev->kobj, NULL, "degraded");
4239         } else {
4240                 if (cmd_match(page, "check"))
4241                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4242                 else if (!cmd_match(page, "repair"))
4243                         return -EINVAL;
4244                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4245                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4246         }
4247         if (mddev->ro == 2) {
4248                 /* A write to sync_action is enough to justify
4249                  * canceling read-auto mode
4250                  */
4251                 mddev->ro = 0;
4252                 md_wakeup_thread(mddev->sync_thread);
4253         }
4254         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4255         md_wakeup_thread(mddev->thread);
4256         sysfs_notify_dirent_safe(mddev->sysfs_action);
4257         return len;
4258 }
4259 
4260 static struct md_sysfs_entry md_scan_mode =
4261 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4262 
4263 static ssize_t
4264 last_sync_action_show(struct mddev *mddev, char *page)
4265 {
4266         return sprintf(page, "%s\n", mddev->last_sync_action);
4267 }
4268 
4269 static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
4270 
4271 static ssize_t
4272 mismatch_cnt_show(struct mddev *mddev, char *page)
4273 {
4274         return sprintf(page, "%llu\n",
4275                        (unsigned long long)
4276                        atomic64_read(&mddev->resync_mismatches));
4277 }
4278 
4279 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4280 
4281 static ssize_t
4282 sync_min_show(struct mddev *mddev, char *page)
4283 {
4284         return sprintf(page, "%d (%s)\n", speed_min(mddev),
4285                        mddev->sync_speed_min ? "local": "system");
4286 }
4287 
4288 static ssize_t
4289 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4290 {
4291         int min;
4292         char *e;
4293         if (strncmp(buf, "system", 6)==0) {
4294                 mddev->sync_speed_min = 0;
4295                 return len;
4296         }
4297         min = simple_strtoul(buf, &e, 10);
4298         if (buf == e || (*e && *e != '\n') || min <= 0)
4299                 return -EINVAL;
4300         mddev->sync_speed_min = min;
4301         return len;
4302 }
4303 
4304 static struct md_sysfs_entry md_sync_min =
4305 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4306 
4307 static ssize_t
4308 sync_max_show(struct mddev *mddev, char *page)
4309 {
4310         return sprintf(page, "%d (%s)\n", speed_max(mddev),
4311                        mddev->sync_speed_max ? "local": "system");
4312 }
4313 
4314 static ssize_t
4315 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4316 {
4317         int max;
4318         char *e;
4319         if (strncmp(buf, "system", 6)==0) {
4320                 mddev->sync_speed_max = 0;
4321                 return len;
4322         }
4323         max = simple_strtoul(buf, &e, 10);
4324         if (buf == e || (*e && *e != '\n') || max <= 0)
4325                 return -EINVAL;
4326         mddev->sync_speed_max = max;
4327         return len;
4328 }
4329 
4330 static struct md_sysfs_entry md_sync_max =
4331 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4332 
4333 static ssize_t
4334 degraded_show(struct mddev *mddev, char *page)
4335 {
4336         return sprintf(page, "%d\n", mddev->degraded);
4337 }
4338 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4339 
4340 static ssize_t
4341 sync_force_parallel_show(struct mddev *mddev, char *page)
4342 {
4343         return sprintf(page, "%d\n", mddev->parallel_resync);
4344 }
4345 
4346 static ssize_t
4347 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4348 {
4349         long n;
4350 
4351         if (kstrtol(buf, 10, &n))
4352                 return -EINVAL;
4353 
4354         if (n != 0 && n != 1)
4355                 return -EINVAL;
4356 
4357         mddev->parallel_resync = n;
4358 
4359         if (mddev->sync_thread)
4360                 wake_up(&resync_wait);
4361 
4362         return len;
4363 }
4364 
4365 /* force parallel resync, even with shared block devices */
4366 static struct md_sysfs_entry md_sync_force_parallel =
4367 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4368        sync_force_parallel_show, sync_force_parallel_store);
4369 
4370 static ssize_t
4371 sync_speed_show(struct mddev *mddev, char *page)
4372 {
4373         unsigned long resync, dt, db;
4374         if (mddev->curr_resync == 0)
4375                 return sprintf(page, "none\n");
4376         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4377         dt = (jiffies - mddev->resync_mark) / HZ;
4378         if (!dt) dt++;
4379         db = resync - mddev->resync_mark_cnt;
4380         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4381 }
4382 
4383 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4384 
4385 static ssize_t
4386 sync_completed_show(struct mddev *mddev, char *page)
4387 {
4388         unsigned long long max_sectors, resync;
4389 
4390         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4391                 return sprintf(page, "none\n");
4392 
4393         if (mddev->curr_resync == 1 ||
4394             mddev->curr_resync == 2)
4395                 return sprintf(page, "delayed\n");
4396 
4397         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4398             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4399                 max_sectors = mddev->resync_max_sectors;
4400         else
4401                 max_sectors = mddev->dev_sectors;
4402 
4403         resync = mddev->curr_resync_completed;
4404         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4405 }
4406 
4407 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4408 
4409 static ssize_t
4410 min_sync_show(struct mddev *mddev, char *page)
4411 {
4412         return sprintf(page, "%llu\n",
4413                        (unsigned long long)mddev->resync_min);
4414 }
4415 static ssize_t
4416 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4417 {
4418         unsigned long long min;
4419         if (kstrtoull(buf, 10, &min))
4420                 return -EINVAL;
4421         if (min > mddev->resync_max)
4422                 return -EINVAL;
4423         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4424                 return -EBUSY;
4425 
4426         /* Must be a multiple of chunk_size */
4427         if (mddev->chunk_sectors) {
4428                 sector_t temp = min;
4429                 if (sector_div(temp, mddev->chunk_sectors))
4430                         return -EINVAL;
4431         }
4432         mddev->resync_min = min;
4433 
4434         return len;
4435 }
4436 
4437 static struct md_sysfs_entry md_min_sync =
4438 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4439 
4440 static ssize_t
4441 max_sync_show(struct mddev *mddev, char *page)
4442 {
4443         if (mddev->resync_max == MaxSector)
4444                 return sprintf(page, "max\n");
4445         else
4446                 return sprintf(page, "%llu\n",
4447                                (unsigned long long)mddev->resync_max);
4448 }
4449 static ssize_t
4450 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4451 {
4452         if (strncmp(buf, "max", 3) == 0)
4453                 mddev->resync_max = MaxSector;
4454         else {
4455                 unsigned long long max;
4456                 if (kstrtoull(buf, 10, &max))
4457                         return -EINVAL;
4458                 if (max < mddev->resync_min)
4459                         return -EINVAL;
4460                 if (max < mddev->resync_max &&
4461                     mddev->ro == 0 &&
4462                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4463                         return -EBUSY;
4464 
4465                 /* Must be a multiple of chunk_size */
4466                 if (mddev->chunk_sectors) {
4467                         sector_t temp = max;
4468                         if (sector_div(temp, mddev->chunk_sectors))
4469                                 return -EINVAL;
4470                 }
4471                 mddev->resync_max = max;
4472         }
4473         wake_up(&mddev->recovery_wait);
4474         return len;
4475 }
4476 
4477 static struct md_sysfs_entry md_max_sync =
4478 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4479 
4480 static ssize_t
4481 suspend_lo_show(struct mddev *mddev, char *page)
4482 {
4483         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4484 }
4485 
4486 static ssize_t
4487 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4488 {
4489         char *e;
4490         unsigned long long new = simple_strtoull(buf, &e, 10);
4491         unsigned long long old = mddev->suspend_lo;
4492 
4493         if (mddev->pers == NULL || 
4494             mddev->pers->quiesce == NULL)
4495                 return -EINVAL;
4496         if (buf == e || (*e && *e != '\n'))
4497                 return -EINVAL;
4498 
4499         mddev->suspend_lo = new;
4500         if (new >= old)
4501                 /* Shrinking suspended region */
4502                 mddev->pers->quiesce(mddev, 2);
4503         else {
4504                 /* Expanding suspended region - need to wait */
4505                 mddev->pers->quiesce(mddev, 1);
4506                 mddev->pers->quiesce(mddev, 0);
4507         }
4508         return len;
4509 }
4510 static struct md_sysfs_entry md_suspend_lo =
4511 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4512 
4513 
4514 static ssize_t
4515 suspend_hi_show(struct mddev *mddev, char *page)
4516 {
4517         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4518 }
4519 
4520 static ssize_t
4521 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4522 {
4523         char *e;
4524         unsigned long long new = simple_strtoull(buf, &e, 10);
4525         unsigned long long old = mddev->suspend_hi;
4526 
4527         if (mddev->pers == NULL ||
4528             mddev->pers->quiesce == NULL)
4529                 return -EINVAL;
4530         if (buf == e || (*e && *e != '\n'))
4531                 return -EINVAL;
4532 
4533         mddev->suspend_hi = new;
4534         if (new <= old)
4535                 /* Shrinking suspended region */
4536                 mddev->pers->quiesce(mddev, 2);
4537         else {
4538                 /* Expanding suspended region - need to wait */
4539                 mddev->pers->quiesce(mddev, 1);
4540                 mddev->pers->quiesce(mddev, 0);
4541         }
4542         return len;
4543 }
4544 static struct md_sysfs_entry md_suspend_hi =
4545 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4546 
4547 static ssize_t
4548 reshape_position_show(struct mddev *mddev, char *page)
4549 {
4550         if (mddev->reshape_position != MaxSector)
4551                 return sprintf(page, "%llu\n",
4552                                (unsigned long long)mddev->reshape_position);
4553         strcpy(page, "none\n");
4554         return 5;
4555 }
4556 
4557 static ssize_t
4558 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4559 {
4560         struct md_rdev *rdev;
4561         char *e;
4562         unsigned long long new = simple_strtoull(buf, &e, 10);
4563         if (mddev->pers)
4564                 return -EBUSY;
4565         if (buf == e || (*e && *e != '\n'))
4566                 return -EINVAL;
4567         mddev->reshape_position = new;
4568         mddev->delta_disks = 0;
4569         mddev->reshape_backwards = 0;
4570         mddev->new_level = mddev->level;
4571         mddev->new_layout = mddev->layout;
4572         mddev->new_chunk_sectors = mddev->chunk_sectors;
4573         rdev_for_each(rdev, mddev)
4574                 rdev->new_data_offset = rdev->data_offset;
4575         return len;
4576 }
4577 
4578 static struct md_sysfs_entry md_reshape_position =
4579 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4580        reshape_position_store);
4581 
4582 static ssize_t
4583 reshape_direction_show(struct mddev *mddev, char *page)
4584 {
4585         return sprintf(page, "%s\n",
4586                        mddev->reshape_backwards ? "backwards" : "forwards");
4587 }
4588 
4589 static ssize_t
4590 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4591 {
4592         int backwards = 0;
4593         if (cmd_match(buf, "forwards"))
4594                 backwards = 0;
4595         else if (cmd_match(buf, "backwards"))
4596                 backwards = 1;
4597         else
4598                 return -EINVAL;
4599         if (mddev->reshape_backwards == backwards)
4600                 return len;
4601 
4602         /* check if we are allowed to change */
4603         if (mddev->delta_disks)
4604                 return -EBUSY;
4605 
4606         if (mddev->persistent &&
4607             mddev->major_version == 0)
4608                 return -EINVAL;
4609 
4610         mddev->reshape_backwards = backwards;
4611         return len;
4612 }
4613 
4614 static struct md_sysfs_entry md_reshape_direction =
4615 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4616        reshape_direction_store);
4617 
4618 static ssize_t
4619 array_size_show(struct mddev *mddev, char *page)
4620 {
4621         if (mddev->external_size)
4622                 return sprintf(page, "%llu\n",
4623                                (unsigned long long)mddev->array_sectors/2);
4624         else
4625                 return sprintf(page, "default\n");
4626 }
4627 
4628 static ssize_t
4629 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4630 {
4631         sector_t sectors;
4632 
4633         if (strncmp(buf, "default", 7) == 0) {
4634                 if (mddev->pers)
4635                         sectors = mddev->pers->size(mddev, 0, 0);
4636                 else
4637                         sectors = mddev->array_sectors;
4638 
4639                 mddev->external_size = 0;
4640         } else {
4641                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
4642                         return -EINVAL;
4643                 if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4644                         return -E2BIG;
4645 
4646                 mddev->external_size = 1;
4647         }
4648 
4649         mddev->array_sectors = sectors;
4650         if (mddev->pers) {
4651                 set_capacity(mddev->gendisk, mddev->array_sectors);
4652                 revalidate_disk(mddev->gendisk);
4653         }
4654         return len;
4655 }
4656 
4657 static struct md_sysfs_entry md_array_size =
4658 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4659        array_size_store);
4660 
4661 static struct attribute *md_default_attrs[] = {
4662         &md_level.attr,
4663         &md_layout.attr,
4664         &md_raid_disks.attr,
4665         &md_chunk_size.attr,
4666         &md_size.attr,
4667         &md_resync_start.attr,
4668         &md_metadata.attr,
4669         &md_new_device.attr,
4670         &md_safe_delay.attr,
4671         &md_array_state.attr,
4672         &md_reshape_position.attr,
4673         &md_reshape_direction.attr,
4674         &md_array_size.attr,
4675         &max_corr_read_errors.attr,
4676         NULL,
4677 };
4678 
4679 static struct attribute *md_redundancy_attrs[] = {
4680         &md_scan_mode.attr,
4681         &md_last_scan_mode.attr,
4682         &md_mismatches.attr,
4683         &md_sync_min.attr,
4684         &md_sync_max.attr,
4685         &md_sync_speed.attr,
4686         &md_sync_force_parallel.attr,
4687         &md_sync_completed.attr,
4688         &md_min_sync.attr,
4689         &md_max_sync.attr,
4690         &md_suspend_lo.attr,
4691         &md_suspend_hi.attr,
4692         &md_bitmap.attr,
4693         &md_degraded.attr,
4694         NULL,
4695 };
4696 static struct attribute_group md_redundancy_group = {
4697         .name = NULL,
4698         .attrs = md_redundancy_attrs,
4699 };
4700 
4701 
4702 static ssize_t
4703 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4704 {
4705         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4706         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4707         ssize_t rv;
4708 
4709         if (!entry->show)
4710                 return -EIO;
4711         spin_lock(&all_mddevs_lock);
4712         if (list_empty(&mddev->all_mddevs)) {
4713                 spin_unlock(&all_mddevs_lock);
4714                 return -EBUSY;
4715         }
4716         mddev_get(mddev);
4717         spin_unlock(&all_mddevs_lock);
4718 
4719         rv = mddev_lock(mddev);
4720         if (!rv) {
4721                 rv = entry->show(mddev, page);
4722                 mddev_unlock(mddev);
4723         }
4724         mddev_put(mddev);
4725         return rv;
4726 }
4727 
4728 static ssize_t
4729 md_attr_store(struct kobject *kobj, struct attribute *attr,
4730               const char *page, size_t length)
4731 {
4732         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4733         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4734         ssize_t rv;
4735 
4736         if (!entry->store)
4737                 return -EIO;
4738         if (!capable(CAP_SYS_ADMIN))
4739                 return -EACCES;
4740         spin_lock(&all_mddevs_lock);
4741         if (list_empty(&mddev->all_mddevs)) {
4742                 spin_unlock(&all_mddevs_lock);
4743                 return -EBUSY;
4744         }
4745         mddev_get(mddev);
4746         spin_unlock(&all_mddevs_lock);
4747         if (entry->store == new_dev_store)
4748                 flush_workqueue(md_misc_wq);
4749         rv = mddev_lock(mddev);
4750         if (!rv) {
4751                 rv = entry->store(mddev, page, length);
4752                 mddev_unlock(mddev);
4753         }
4754         mddev_put(mddev);
4755         return rv;
4756 }
4757 
4758 static void md_free(struct kobject *ko)
4759 {
4760         struct mddev *mddev = container_of(ko, struct mddev, kobj);
4761 
4762         if (mddev->sysfs_state)
4763                 sysfs_put(mddev->sysfs_state);
4764 
4765         if (mddev->gendisk) {
4766                 del_gendisk(mddev->gendisk);
4767                 put_disk(mddev->gendisk);
4768         }
4769         if (mddev->queue)
4770                 blk_cleanup_queue(mddev->queue);
4771 
4772         kfree(mddev);
4773 }
4774 
4775 static const struct sysfs_ops md_sysfs_ops = {
4776         .show   = md_attr_show,
4777         .store  = md_attr_store,
4778 };
4779 static struct kobj_type md_ktype = {
4780         .release        = md_free,
4781         .sysfs_ops      = &md_sysfs_ops,
4782         .default_attrs  = md_default_attrs,
4783 };
4784 
4785 int mdp_major = 0;
4786 
4787 static void mddev_delayed_delete(struct work_struct *ws)
4788 {
4789         struct mddev *mddev = container_of(ws, struct mddev, del_work);
4790 
4791         sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4792         kobject_del(&mddev->kobj);
4793         kobject_put(&mddev->kobj);
4794 }
4795 
4796 static int md_alloc(dev_t dev, char *name)
4797 {
4798         static DEFINE_MUTEX(disks_mutex);
4799         struct mddev *mddev = mddev_find(dev);
4800         struct gendisk *disk;
4801         int partitioned;
4802         int shift;
4803         int unit;
4804         int error;
4805 
4806         if (!mddev)
4807                 return -ENODEV;
4808 
4809         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4810         shift = partitioned ? MdpMinorShift : 0;
4811         unit = MINOR(mddev->unit) >> shift;
4812 
4813         /* wait for any previous instance of this device to be
4814          * completely removed (mddev_delayed_delete).
4815          */
4816         flush_workqueue(md_misc_wq);
4817 
4818         mutex_lock(&disks_mutex);
4819         error = -EEXIST;
4820         if (mddev->gendisk)
4821                 goto abort;
4822 
4823         if (name) {
4824                 /* Need to ensure that 'name' is not a duplicate.
4825                  */
4826                 struct mddev *mddev2;
4827                 spin_lock(&all_mddevs_lock);
4828 
4829                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4830                         if (mddev2->gendisk &&
4831                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
4832                                 spin_unlock(&all_mddevs_lock);
4833                                 goto abort;
4834                         }
4835                 spin_unlock(&all_mddevs_lock);
4836         }
4837 
4838         error = -ENOMEM;
4839         mddev->queue = blk_alloc_queue(GFP_KERNEL);
4840         if (!mddev->queue)
4841                 goto abort;
4842         mddev->queue->queuedata = mddev;
4843 
4844         blk_queue_make_request(mddev->queue, md_make_request);
4845         blk_set_stacking_limits(&mddev->queue->limits);
4846 
4847         disk = alloc_disk(1 << shift);
4848         if (!disk) {
4849                 blk_cleanup_queue(mddev->queue);
4850                 mddev->queue = NULL;
4851                 goto abort;
4852         }
4853         disk->major = MAJOR(mddev->unit);
4854         disk->first_minor = unit << shift;
4855         if (name)
4856                 strcpy(disk->disk_name, name);
4857         else if (partitioned)
4858                 sprintf(disk->disk_name, "md_d%d", unit);
4859         else
4860                 sprintf(disk->disk_name, "md%d", unit);
4861         disk->fops = &md_fops;
4862         disk->private_data = mddev;
4863         disk->queue = mddev->queue;
4864         blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4865         /* Allow extended partitions.  This makes the
4866          * 'mdp' device redundant, but we can't really
4867          * remove it now.
4868          */
4869         disk->flags |= GENHD_FL_EXT_DEVT;
4870         mddev->gendisk = disk;
4871         /* As soon as we call add_disk(), another thread could get
4872          * through to md_open, so make sure it doesn't get too far
4873          */
4874         mutex_lock(&mddev->open_mutex);
4875         add_disk(disk);
4876 
4877         error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4878                                      &disk_to_dev(disk)->kobj, "%s", "md");
4879         if (error) {
4880                 /* This isn't possible, but as kobject_init_and_add is marked
4881                  * __must_check, we must do something with the result
4882                  */
4883                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4884                        disk->disk_name);
4885                 error = 0;
4886         }
4887         if (mddev->kobj.sd &&
4888             sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4889                 printk(KERN_DEBUG "pointless warning\n");
4890         mutex_unlock(&mddev->open_mutex);
4891  abort:
4892         mutex_unlock(&disks_mutex);
4893         if (!error && mddev->kobj.sd) {
4894                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
4895                 mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4896         }
4897         mddev_put(mddev);
4898         return error;
4899 }
4900 
4901 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4902 {
4903         md_alloc(dev, NULL);
4904         return NULL;
4905 }
4906 
4907 static int add_named_array(const char *val, struct kernel_param *kp)
4908 {
4909         /* val must be "md_*" where * is not all digits.
4910          * We allocate an array with a large free minor number, and
4911          * set the name to val.  val must not already be an active name.
4912          */
4913         int len = strlen(val);
4914         char buf[DISK_NAME_LEN];
4915 
4916         while (len && val[len-1] == '\n')
4917                 len--;
4918         if (len >= DISK_NAME_LEN)
4919                 return -E2BIG;
4920         strlcpy(buf, val, len+1);
4921         if (strncmp(buf, "md_", 3) != 0)
4922                 return -EINVAL;
4923         return md_alloc(0, buf);
4924 }
4925 
4926 static void md_safemode_timeout(unsigned long data)
4927 {
4928         struct mddev *mddev = (struct mddev *) data;
4929 
4930         if (!atomic_read(&mddev->writes_pending)) {
4931                 mddev->safemode = 1;
4932                 if (mddev->external)
4933                         sysfs_notify_dirent_safe(mddev->sysfs_state);
4934         }
4935         md_wakeup_thread(mddev->thread);
4936 }
4937 
4938 static int start_dirty_degraded;
4939 
4940 int md_run(struct mddev *mddev)
4941 {
4942         int err;
4943         struct md_rdev *rdev;
4944         struct md_personality *pers;
4945 
4946         if (list_empty(&mddev->disks))
4947                 /* cannot run an array with no devices.. */
4948                 return -EINVAL;
4949 
4950         if (mddev->pers)
4951                 return -EBUSY;
4952         /* Cannot run until previous stop completes properly */
4953         if (mddev->sysfs_active)
4954                 return -EBUSY;
4955 
4956         /*
4957          * Analyze all RAID superblock(s)
4958          */
4959         if (!mddev->raid_disks) {
4960                 if (!mddev->persistent)
4961                         return -EINVAL;
4962                 analyze_sbs(mddev);
4963         }
4964 
4965         if (mddev->level != LEVEL_NONE)
4966                 request_module("md-level-%d", mddev->level);
4967         else if (mddev->clevel[0])
4968                 request_module("md-%s", mddev->clevel);
4969 
4970         /*
4971          * Drop all container device buffers, from now on
4972          * the only valid external interface is through the md
4973          * device.
4974          */
4975         rdev_for_each(rdev, mddev) {
4976                 if (test_bit(Faulty, &rdev->flags))
4977                         continue;
4978                 sync_blockdev(rdev->bdev);
4979                 invalidate_bdev(rdev->bdev);
4980 
4981                 /* perform some consistency tests on the device.
4982                  * We don't want the data to overlap the metadata,
4983                  * Internal Bitmap issues have been handled elsewhere.
4984                  */
4985                 if (rdev->meta_bdev) {
4986                         /* Nothing to check */;
4987                 } else if (rdev->data_offset < rdev->sb_start) {
4988                         if (mddev->dev_sectors &&
4989                             rdev->data_offset + mddev->dev_sectors
4990                             > rdev->sb_start) {
4991                                 printk("md: %s: data overlaps metadata\n",
4992                                        mdname(mddev));
4993                                 return -EINVAL;
4994                         }
4995                 } else {
4996                         if (rdev->sb_start + rdev->sb_size/512
4997                             > rdev->data_offset) {
4998                                 printk("md: %s: metadata overlaps data\n",
4999                                        mdname(mddev));
5000                                 return -EINVAL;
5001                         }
5002                 }
5003                 sysfs_notify_dirent_safe(rdev->sysfs_state);
5004         }
5005 
5006         if (mddev->bio_set == NULL)
5007                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
5008 
5009         spin_lock(&pers_lock);
5010         pers = find_pers(mddev->level, mddev->clevel);
5011         if (!pers || !try_module_get(pers->owner)) {
5012                 spin_unlock(&pers_lock);
5013                 if (mddev->level != LEVEL_NONE)
5014                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5015                                mddev->level);
5016                 else
5017                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5018                                mddev->clevel);
5019                 return -EINVAL;
5020         }
5021         mddev->pers = pers;
5022         spin_unlock(&pers_lock);
5023         if (mddev->level != pers->level) {
5024                 mddev->level = pers->level;
5025                 mddev->new_level = pers->level;
5026         }
5027         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5028 
5029         if (mddev->reshape_position != MaxSector &&
5030             pers->start_reshape == NULL) {
5031                 /* This personality cannot handle reshaping... */
5032                 mddev->pers = NULL;
5033                 module_put(pers->owner);
5034                 return -EINVAL;
5035         }
5036 
5037         if (pers->sync_request) {
5038                 /* Warn if this is a potentially silly
5039                  * configuration.
5040                  */
5041                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5042                 struct md_rdev *rdev2;
5043                 int warned = 0;
5044 
5045                 rdev_for_each(rdev, mddev)
5046                         rdev_for_each(rdev2, mddev) {
5047                                 if (rdev < rdev2 &&
5048                                     rdev->bdev->bd_contains ==
5049                                     rdev2->bdev->bd_contains) {
5050                                         printk(KERN_WARNING
5051                                                "%s: WARNING: %s appears to be"
5052                                                " on the same physical disk as"
5053                                                " %s.\n",
5054                                                mdname(mddev),
5055                                                bdevname(rdev->bdev,b),
5056                                                bdevname(rdev2->bdev,b2));
5057                                         warned = 1;
5058                                 }
5059                         }
5060 
5061                 if (warned)
5062                         printk(KERN_WARNING
5063                                "True protection against single-disk"
5064                                " failure might be compromised.\n");
5065         }
5066 
5067         mddev->recovery = 0;
5068         /* may be over-ridden by personality */
5069         mddev->resync_max_sectors = mddev->dev_sectors;
5070 
5071         mddev->ok_start_degraded = start_dirty_degraded;
5072 
5073         if (start_readonly && mddev->ro == 0)
5074                 mddev->ro = 2; /* read-only, but switch on first write */
5075 
5076         err = mddev->pers->run(mddev);
5077         if (err)
5078                 printk(KERN_ERR "md: pers->run() failed ...\n");
5079         else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
5080                 WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5081                           " but 'external_size' not in effect?\n", __func__);
5082                 printk(KERN_ERR
5083                        "md: invalid array_size %llu > default size %llu\n",
5084                        (unsigned long long)mddev->array_sectors / 2,
5085                        (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
5086                 err = -EINVAL;
5087                 mddev->pers->stop(mddev);
5088         }
5089         if (err == 0 && mddev->pers->sync_request &&
5090             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5091                 err = bitmap_create(mddev);
5092                 if (err) {
5093                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5094                                mdname(mddev), err);
5095                         mddev->pers->stop(mddev);
5096                 }
5097         }
5098         if (err) {
5099                 module_put(mddev->pers->owner);
5100                 mddev->pers = NULL;
5101                 bitmap_destroy(mddev);
5102                 return err;
5103         }
5104         if (mddev->pers->sync_request) {
5105                 if (mddev->kobj.sd &&
5106                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5107                         printk(KERN_WARNING
5108                                "md: cannot register extra attributes for %s\n",
5109                                mdname(mddev));
5110                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5111         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
5112                 mddev->ro = 0;
5113 
5114         atomic_set(&mddev->writes_pending,0);
5115         atomic_set(&mddev->max_corr_read_errors,
5116                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5117         mddev->safemode = 0;
5118         mddev->safemode_timer.function = md_safemode_timeout;
5119         mddev->safemode_timer.data = (unsigned long) mddev;
5120         mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5121         mddev->in_sync = 1;
5122         smp_wmb();
5123         mddev->ready = 1;
5124         rdev_for_each(rdev, mddev)
5125                 if (rdev->raid_disk >= 0)
5126                         if (sysfs_link_rdev(mddev, rdev))
5127                                 /* failure here is OK */;
5128         
5129         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5130         
5131         if (mddev->flags & MD_UPDATE_SB_FLAGS)
5132                 md_update_sb(mddev, 0);
5133 
5134         md_new_event(mddev);
5135         sysfs_notify_dirent_safe(mddev->sysfs_state);
5136         sysfs_notify_dirent_safe(mddev->sysfs_action);
5137         sysfs_notify(&mddev->kobj, NULL, "degraded");
5138         return 0;
5139 }
5140 EXPORT_SYMBOL_GPL(md_run);
5141 
5142 static int do_md_run(struct mddev *mddev)
5143 {
5144         int err;
5145 
5146         err = md_run(mddev);
5147         if (err)
5148                 goto out;
5149         err = bitmap_load(mddev);
5150         if (err) {
5151                 bitmap_destroy(mddev);
5152                 goto out;
5153         }
5154 
5155         md_wakeup_thread(mddev->thread);
5156         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5157 
5158         set_capacity(mddev->gendisk, mddev->array_sectors);
5159         revalidate_disk(mddev->gendisk);
5160         mddev->changed = 1;
5161         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5162 out:
5163         return err;
5164 }
5165 
5166 static int restart_array(struct mddev *mddev)
5167 {
5168         struct gendisk *disk = mddev->gendisk;
5169 
5170         /* Complain if it has no devices */
5171         if (list_empty(&mddev->disks))
5172                 return -ENXIO;
5173         if (!mddev->pers)
5174                 return -EINVAL;
5175         if (!mddev->ro)
5176                 return -EBUSY;
5177         mddev->safemode = 0;
5178         mddev->ro = 0;
5179         set_disk_ro(disk, 0);
5180         printk(KERN_INFO "md: %s switched to read-write mode.\n",
5181                 mdname(mddev));
5182         /* Kick recovery or resync if necessary */
5183         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5184         md_wakeup_thread(mddev->thread);
5185         md_wakeup_thread(mddev->sync_thread);
5186         sysfs_notify_dirent_safe(mddev->sysfs_state);
5187         return 0;
5188 }
5189 
5190 static void md_clean(struct mddev *mddev)
5191 {
5192         mddev->array_sectors = 0;
5193         mddev->external_size = 0;
5194         mddev->dev_sectors = 0;
5195         mddev->raid_disks = 0;
5196         mddev->recovery_cp = 0;
5197         mddev->resync_min = 0;
5198         mddev->resync_max = MaxSector;
5199         mddev->reshape_position = MaxSector;
5200         mddev->external = 0;
5201         mddev->persistent = 0;
5202         mddev->level = LEVEL_NONE;
5203         mddev->clevel[0] = 0;
5204         mddev->flags = 0;
5205         mddev->ro = 0;
5206         mddev->metadata_type[0] = 0;
5207         mddev->chunk_sectors = 0;
5208         mddev->ctime = mddev->utime = 0;
5209         mddev->layout = 0;
5210         mddev->max_disks = 0;
5211         mddev->events = 0;
5212         mddev->can_decrease_events = 0;
5213         mddev->delta_disks = 0;
5214         mddev->reshape_backwards = 0;
5215         mddev->new_level = LEVEL_NONE;
5216         mddev->new_layout = 0;
5217         mddev->new_chunk_sectors = 0;
5218         mddev->curr_resync = 0;
5219         atomic64_set(&mddev->resync_mismatches, 0);
5220         mddev->suspend_lo = mddev->suspend_hi = 0;
5221         mddev->sync_speed_min = mddev->sync_speed_max = 0;
5222         mddev->recovery = 0;
5223         mddev->in_sync = 0;
5224         mddev->changed = 0;
5225         mddev->degraded = 0;
5226         mddev->safemode = 0;
5227         mddev->merge_check_needed = 0;
5228         mddev->bitmap_info.offset = 0;
5229         mddev->bitmap_info.default_offset = 0;
5230         mddev->bitmap_info.default_space = 0;
5231         mddev->bitmap_info.chunksize = 0;
5232         mddev->bitmap_info.daemon_sleep = 0;
5233         mddev->bitmap_info.max_write_behind = 0;
5234 }
5235 
5236 static void __md_stop_writes(struct mddev *mddev)
5237 {
5238         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5239         if (mddev->sync_thread) {
5240                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5241                 md_reap_sync_thread(mddev);
5242         }
5243 
5244         del_timer_sync(&mddev->safemode_timer);
5245 
5246         bitmap_flush(mddev);
5247         md_super_wait(mddev);
5248 
5249         if (mddev->ro == 0 &&
5250             (!mddev->in_sync || (mddev->flags & MD_UPDATE_SB_FLAGS))) {
5251                 /* mark array as shutdown cleanly */
5252                 mddev->in_sync = 1;
5253                 md_update_sb(mddev, 1);
5254         }
5255 }
5256 
5257 void md_stop_writes(struct mddev *mddev)
5258 {
5259         mddev_lock_nointr(mddev);
5260         __md_stop_writes(mddev);
5261         mddev_unlock(mddev);
5262 }
5263 EXPORT_SYMBOL_GPL(md_stop_writes);
5264 
5265 static void __md_stop(struct mddev *mddev)
5266 {
5267         mddev->ready = 0;
5268         mddev->pers->stop(mddev);
5269         if (mddev->pers->sync_request && mddev->to_remove == NULL)
5270                 mddev->to_remove = &md_redundancy_group;
5271         module_put(mddev->pers->owner);
5272         mddev->pers = NULL;
5273         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5274 }
5275 
5276 void md_stop(struct mddev *mddev)
5277 {
5278         /* stop the array and free an attached data structures.
5279          * This is called from dm-raid
5280          */
5281         __md_stop(mddev);
5282         bitmap_destroy(mddev);
5283         if (mddev->bio_set)
5284                 bioset_free(mddev->bio_set);
5285 }
5286 
5287 EXPORT_SYMBOL_GPL(md_stop);
5288 
5289 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5290 {
5291         int err = 0;
5292         int did_freeze = 0;
5293 
5294         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5295                 did_freeze = 1;
5296                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5297                 md_wakeup_thread(mddev->thread);
5298         }
5299         if (mddev->sync_thread) {
5300                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5301                 /* Thread might be blocked waiting for metadata update
5302                  * which will now never happen */
5303                 wake_up_process(mddev->sync_thread->tsk);
5304         }
5305         mddev_unlock(mddev);
5306         wait_event(resync_wait, mddev->sync_thread == NULL);
5307         mddev_lock_nointr(mddev);
5308 
5309         mutex_lock(&mddev->open_mutex);
5310         if (atomic_read(&mddev->openers) > !!bdev ||
5311             mddev->sync_thread ||
5312             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5313                 printk("md: %s still in use.\n",mdname(mddev));
5314                 if (did_freeze) {
5315                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5316                         md_wakeup_thread(mddev->thread);
5317                 }
5318                 err = -EBUSY;
5319                 goto out;
5320         }
5321         if (mddev->pers) {
5322                 __md_stop_writes(mddev);
5323 
5324                 err  = -ENXIO;
5325                 if (mddev->ro==1)
5326                         goto out;
5327                 mddev->ro = 1;
5328                 set_disk_ro(mddev->gendisk, 1);
5329                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5330                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5331                 err = 0;
5332         }
5333 out:
5334         mutex_unlock(&mddev->open_mutex);
5335         return err;
5336 }
5337 
5338 /* mode:
5339  *   0 - completely stop and dis-assemble array
5340  *   2 - stop but do not disassemble array
5341  */
5342 static int do_md_stop(struct mddev * mddev, int mode,
5343                       struct block_device *bdev)
5344 {
5345         struct gendisk *disk = mddev->gendisk;
5346         struct md_rdev *rdev;
5347         int did_freeze = 0;
5348 
5349         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5350                 did_freeze = 1;
5351                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5352                 md_wakeup_thread(mddev->thread);
5353         }
5354         if (mddev->sync_thread) {
5355                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5356                 /* Thread might be blocked waiting for metadata update
5357                  * which will now never happen */
5358                 wake_up_process(mddev->sync_thread->tsk);
5359         }
5360         mddev_unlock(mddev);
5361         wait_event(resync_wait, mddev->sync_thread == NULL);
5362         mddev_lock_nointr(mddev);
5363 
5364         mutex_lock(&mddev->open_mutex);
5365         if (atomic_read(&mddev->openers) > !!bdev ||
5366             mddev->sysfs_active ||
5367             mddev->sync_thread ||
5368             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5369                 printk("md: %s still in use.\n",mdname(mddev));
5370                 mutex_unlock(&mddev->open_mutex);
5371                 if (did_freeze) {
5372                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5373                         md_wakeup_thread(mddev->thread);
5374                 }
5375                 return -EBUSY;
5376         }
5377         if (mddev->pers) {
5378                 if (mddev->ro)
5379                         set_disk_ro(disk, 0);
5380 
5381                 __md_stop_writes(mddev);
5382                 __md_stop(mddev);
5383                 mddev->queue->merge_bvec_fn = NULL;
5384                 mddev->queue->backing_dev_info.congested_fn = NULL;
5385 
5386                 /* tell userspace to handle 'inactive' */
5387                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5388 
5389                 rdev_for_each(rdev, mddev)
5390                         if (rdev->raid_disk >= 0)
5391                                 sysfs_unlink_rdev(mddev, rdev);
5392 
5393                 set_capacity(disk, 0);
5394                 mutex_unlock(&mddev->open_mutex);
5395                 mddev->changed = 1;
5396                 revalidate_disk(disk);
5397 
5398                 if (mddev->ro)
5399                         mddev->ro = 0;
5400         } else
5401                 mutex_unlock(&mddev->open_mutex);
5402         /*
5403          * Free resources if final stop
5404          */
5405         if (mode == 0) {
5406                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5407 
5408                 bitmap_destroy(mddev);
5409                 if (mddev->bitmap_info.file) {
5410                         fput(mddev->bitmap_info.file);
5411                         mddev->bitmap_info.file = NULL;
5412                 }
5413                 mddev->bitmap_info.offset = 0;
5414 
5415                 export_array(mddev);
5416 
5417                 md_clean(mddev);
5418                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5419                 if (mddev->hold_active == UNTIL_STOP)
5420                         mddev->hold_active = 0;
5421         }
5422         blk_integrity_unregister(disk);
5423         md_new_event(mddev);
5424         sysfs_notify_dirent_safe(mddev->sysfs_state);
5425         return 0;
5426 }
5427 
5428 #ifndef MODULE
5429 static void autorun_array(struct mddev *mddev)
5430 {
5431         struct md_rdev *rdev;
5432         int err;
5433 
5434         if (list_empty(&mddev->disks))
5435                 return;
5436 
5437         printk(KERN_INFO "md: running: ");
5438 
5439         rdev_for_each(rdev, mddev) {
5440                 char b[BDEVNAME_SIZE];
5441                 printk("<%s>", bdevname(rdev->bdev,b));
5442         }
5443         printk("\n");
5444 
5445         err = do_md_run(mddev);
5446         if (err) {
5447                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5448                 do_md_stop(mddev, 0, NULL);
5449         }
5450 }
5451 
5452 /*
5453  * lets try to run arrays based on all disks that have arrived
5454  * until now. (those are in pending_raid_disks)
5455  *
5456  * the method: pick the first pending disk, collect all disks with
5457  * the same UUID, remove all from the pending list and put them into
5458  * the 'same_array' list. Then order this list based on superblock
5459  * update time (freshest comes first), kick out 'old' disks and
5460  * compare superblocks. If everything's fine then run it.
5461  *
5462  * If "unit" is allocated, then bump its reference count
5463  */
5464 static void autorun_devices(int part)
5465 {
5466         struct md_rdev *rdev0, *rdev, *tmp;
5467         struct mddev *mddev;
5468         char b[BDEVNAME_SIZE];
5469 
5470         printk(KERN_INFO "md: autorun ...\n");
5471         while (!list_empty(&pending_raid_disks)) {
5472                 int unit;
5473                 dev_t dev;
5474                 LIST_HEAD(candidates);
5475                 rdev0 = list_entry(pending_raid_disks.next,
5476                                          struct md_rdev, same_set);
5477 
5478                 printk(KERN_INFO "md: considering %s ...\n",
5479                         bdevname(rdev0->bdev,b));
5480                 INIT_LIST_HEAD(&candidates);
5481                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5482                         if (super_90_load(rdev, rdev0, 0) >= 0) {
5483                                 printk(KERN_INFO "md:  adding %s ...\n",
5484                                         bdevname(rdev->bdev,b));
5485                                 list_move(&rdev->same_set, &candidates);
5486                         }
5487                 /*
5488                  * now we have a set of devices, with all of them having
5489                  * mostly sane superblocks. It's time to allocate the
5490                  * mddev.
5491                  */
5492                 if (part) {
5493                         dev = MKDEV(mdp_major,
5494                                     rdev0->preferred_minor << MdpMinorShift);
5495                         unit = MINOR(dev) >> MdpMinorShift;
5496                 } else {
5497                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5498                         unit = MINOR(dev);
5499                 }
5500                 if (rdev0->preferred_minor != unit) {
5501                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5502                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5503                         break;
5504                 }
5505 
5506                 md_probe(dev, NULL, NULL);
5507                 mddev = mddev_find(dev);
5508                 if (!mddev || !mddev->gendisk) {
5509                         if (mddev)
5510                                 mddev_put(mddev);
5511                         printk(KERN_ERR
5512                                 "md: cannot allocate memory for md drive.\n");
5513                         break;
5514                 }
5515                 if (mddev_lock(mddev)) 
5516                         printk(KERN_WARNING "md: %s locked, cannot run\n",
5517                                mdname(mddev));
5518                 else if (mddev->raid_disks || mddev->major_version
5519                          || !list_empty(&mddev->disks)) {
5520                         printk(KERN_WARNING 
5521                                 "md: %s already running, cannot run %s\n",
5522                                 mdname(mddev), bdevname(rdev0->bdev,b));
5523                         mddev_unlock(mddev);
5524                 } else {
5525                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
5526                         mddev->persistent = 1;
5527                         rdev_for_each_list(rdev, tmp, &candidates) {
5528                                 list_del_init(&rdev->same_set);
5529                                 if (bind_rdev_to_array(rdev, mddev))
5530                                         export_rdev(rdev);
5531                         }
5532                         autorun_array(mddev);
5533                         mddev_unlock(mddev);
5534                 }
5535                 /* on success, candidates will be empty, on error
5536                  * it won't...
5537                  */
5538                 rdev_for_each_list(rdev, tmp, &candidates) {
5539                         list_del_init(&rdev->same_set);
5540                         export_rdev(rdev);
5541                 }
5542                 mddev_put(mddev);
5543         }
5544         printk(KERN_INFO "md: ... autorun DONE.\n");
5545 }
5546 #endif /* !MODULE */
5547 
5548 static int get_version(void __user * arg)
5549 {
5550         mdu_version_t ver;
5551 
5552         ver.major = MD_MAJOR_VERSION;
5553         ver.minor = MD_MINOR_VERSION;
5554         ver.patchlevel = MD_PATCHLEVEL_VERSION;
5555 
5556         if (copy_to_user(arg, &ver, sizeof(ver)))
5557                 return -EFAULT;
5558 
5559         return 0;
5560 }
5561 
5562 static int get_array_info(struct mddev * mddev, void __user * arg)
5563 {
5564         mdu_array_info_t info;
5565         int nr,working,insync,failed,spare;
5566         struct md_rdev *rdev;
5567 
5568         nr = working = insync = failed = spare = 0;
5569         rcu_read_lock();
5570         rdev_for_each_rcu(rdev, mddev) {
5571                 nr++;
5572                 if (test_bit(Faulty, &rdev->flags))
5573                         failed++;
5574                 else {
5575                         working++;
5576                         if (test_bit(In_sync, &rdev->flags))
5577                                 insync++;       
5578                         else
5579                                 spare++;
5580                 }
5581         }
5582         rcu_read_unlock();
5583 
5584         info.major_version = mddev->major_version;
5585         info.minor_version = mddev->minor_version;
5586         info.patch_version = MD_PATCHLEVEL_VERSION;
5587         info.ctime         = mddev->ctime;
5588         info.level         = mddev->level;
5589         info.size          = mddev->dev_sectors / 2;
5590         if (info.size != mddev->dev_sectors / 2) /* overflow */
5591                 info.size = -1;
5592         info.nr_disks      = nr;
5593         info.raid_disks    = mddev->raid_disks;
5594         info.md_minor      = mddev->md_minor;
5595         info.not_persistent= !mddev->persistent;
5596 
5597         info.utime         = mddev->utime;
5598         info.state         = 0;
5599         if (mddev->in_sync)
5600                 info.state = (1<<MD_SB_CLEAN);
5601         if (mddev->bitmap && mddev->bitmap_info.offset)
5602                 info.state |= (1<<MD_SB_BITMAP_PRESENT);
5603         info.active_disks  = insync;
5604         info.working_disks = working;
5605         info.failed_disks  = failed;
5606         info.spare_disks   = spare;
5607 
5608         info.layout        = mddev->layout;
5609         info.chunk_size    = mddev->chunk_sectors << 9;
5610 
5611         if (copy_to_user(arg, &info, sizeof(info)))
5612                 return -EFAULT;
5613 
5614         return 0;
5615 }
5616 
5617 static int get_bitmap_file(struct mddev * mddev, void __user * arg)
5618 {
5619         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5620         char *ptr, *buf = NULL;
5621         int err = -ENOMEM;
5622 
5623         file = kmalloc(sizeof(*file), GFP_NOIO);
5624 
5625         if (!file)
5626                 goto out;
5627 
5628         /* bitmap disabled, zero the first byte and copy out */
5629         if (!mddev->bitmap || !mddev->bitmap->storage.file) {
5630                 file->pathname[0] = '\0';
5631                 goto copy_out;
5632         }
5633 
5634         buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5635         if (!buf)
5636                 goto out;
5637 
5638         ptr = d_path(&mddev->bitmap->storage.file->f_path,
5639                      buf, sizeof(file->pathname));
5640         if (IS_ERR(ptr))
5641                 goto out;
5642 
5643         strcpy(file->pathname, ptr);
5644 
5645 copy_out:
5646         err = 0;
5647         if (copy_to_user(arg, file, sizeof(*file)))
5648                 err = -EFAULT;
5649 out:
5650         kfree(buf);
5651         kfree(file);
5652         return err;
5653 }
5654 
5655 static int get_disk_info(struct mddev * mddev, void __user * arg)
5656 {
5657         mdu_disk_info_t info;
5658         struct md_rdev *rdev;
5659 
5660         if (copy_from_user(&info, arg, sizeof(info)))
5661                 return -EFAULT;
5662 
5663         rcu_read_lock();
5664         rdev = find_rdev_nr_rcu(mddev, info.number);
5665         if (rdev) {
5666                 info.major = MAJOR(rdev->bdev->bd_dev);
5667                 info.minor = MINOR(rdev->bdev->bd_dev);
5668                 info.raid_disk = rdev->raid_disk;
5669                 info.state = 0;
5670                 if (test_bit(Faulty, &rdev->flags))
5671                         info.state |= (1<<MD_DISK_FAULTY);
5672                 else if (test_bit(In_sync, &rdev->flags)) {
5673                         info.state |= (1<<MD_DISK_ACTIVE);
5674                         info.state |= (1<<MD_DISK_SYNC);
5675                 }
5676                 if (test_bit(WriteMostly, &rdev->flags))
5677                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
5678         } else {
5679                 info.major = info.minor = 0;
5680                 info.raid_disk = -1;
5681                 info.state = (1<<MD_DISK_REMOVED);
5682         }
5683         rcu_read_unlock();
5684 
5685         if (copy_to_user(arg, &info, sizeof(info)))
5686                 return -EFAULT;
5687 
5688         return 0;
5689 }
5690 
5691 static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info)
5692 {
5693         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5694         struct md_rdev *rdev;
5695         dev_t dev = MKDEV(info->major,info->minor);
5696 
5697         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5698                 return -EOVERFLOW;
5699 
5700         if (!mddev->raid_disks) {
5701                 int err;
5702                 /* expecting a device which has a superblock */
5703                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5704                 if (IS_ERR(rdev)) {
5705                         printk(KERN_WARNING 
5706                                 "md: md_import_device returned %ld\n",
5707                                 PTR_ERR(rdev));
5708                         return PTR_ERR(rdev);
5709                 }
5710                 if (!list_empty(&mddev->disks)) {
5711                         struct md_rdev *rdev0
5712                                 = list_entry(mddev->disks.next,
5713                                              struct md_rdev, same_set);
5714                         err = super_types[mddev->major_version]
5715                                 .load_super(rdev, rdev0, mddev->minor_version);
5716                         if (err < 0) {
5717                                 printk(KERN_WARNING 
5718                                         "md: %s has different UUID to %s\n",
5719                                         bdevname(rdev->bdev,b), 
5720                                         bdevname(rdev0->bdev,b2));
5721                                 export_rdev(rdev);
5722                                 return -EINVAL;
5723                         }
5724                 }
5725                 err = bind_rdev_to_array(rdev, mddev);
5726                 if (err)
5727                         export_rdev(rdev);
5728                 return err;
5729         }
5730 
5731         /*
5732          * add_new_disk can be used once the array is assembled
5733          * to add "hot spares".  They must already have a superblock
5734          * written
5735          */
5736         if (mddev->pers) {
5737                 int err;
5738                 if (!mddev->pers->hot_add_disk) {
5739                         printk(KERN_WARNING 
5740                                 "%s: personality does not support diskops!\n",
5741                                mdname(mddev));
5742                         return -EINVAL;
5743                 }
5744                 if (mddev->persistent)
5745                         rdev = md_import_device(dev, mddev->major_version,
5746                                                 mddev->minor_version);
5747                 else
5748                         rdev = md_import_device(dev, -1, -1);
5749                 if (IS_ERR(rdev)) {
5750                         printk(KERN_WARNING 
5751                                 "md: md_import_device returned %ld\n",
5752                                 PTR_ERR(rdev));
5753                         return PTR_ERR(rdev);
5754                 }
5755                 /* set saved_raid_disk if appropriate */
5756                 if (!mddev->persistent) {
5757                         if (info->state & (1<<MD_DISK_SYNC)  &&
5758                             info->raid_disk < mddev->raid_disks) {
5759                                 rdev->raid_disk = info->raid_disk;
5760                                 set_bit(In_sync, &rdev->flags);
5761                                 clear_bit(Bitmap_sync, &rdev->flags);
5762                         } else
5763                                 rdev->raid_disk = -1;
5764                         rdev->saved_raid_disk = rdev->raid_disk;
5765                 } else
5766                         super_types[mddev->major_version].
5767                                 validate_super(mddev, rdev);
5768                 if ((info->state & (1<<MD_DISK_SYNC)) &&
5769                      rdev->raid_disk != info->raid_disk) {
5770                         /* This was a hot-add request, but events doesn't
5771                          * match, so reject it.
5772                          */
5773                         export_rdev(rdev);
5774                         return -EINVAL;
5775                 }
5776 
5777                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
5778                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5779                         set_bit(WriteMostly, &rdev->flags);
5780                 else
5781                         clear_bit(WriteMostly, &rdev->flags);
5782 
5783                 rdev->raid_disk = -1;
5784                 err = bind_rdev_to_array(rdev, mddev);
5785                 if (!err && !mddev->pers->hot_remove_disk) {
5786                         /* If there is hot_add_disk but no hot_remove_disk
5787                          * then added disks for geometry changes,
5788                          * and should be added immediately.
5789                          */
5790                         super_types[mddev->major_version].
5791                                 validate_super(mddev, rdev);
5792                         err = mddev->pers->hot_add_disk(mddev, rdev);
5793                         if (err)
5794                                 unbind_rdev_from_array(rdev);
5795                 }
5796                 if (err)
5797                         export_rdev(rdev);
5798                 else
5799                         sysfs_notify_dirent_safe(rdev->sysfs_state);
5800 
5801                 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5802                 if (mddev->degraded)
5803                         set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5804                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5805                 if (!err)
5806                         md_new_event(mddev);
5807                 md_wakeup_thread(mddev->thread);
5808                 return err;
5809         }
5810 
5811         /* otherwise, add_new_disk is only allowed
5812          * for major_version==0 superblocks
5813          */
5814         if (mddev->major_version != 0) {
5815                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5816                        mdname(mddev));
5817                 return -EINVAL;
5818         }
5819 
5820         if (!(info->state & (1<<MD_DISK_FAULTY))) {
5821                 int err;
5822                 rdev = md_import_device(dev, -1, 0);
5823                 if (IS_ERR(rdev)) {
5824                         printk(KERN_WARNING 
5825                                 "md: error, md_import_device() returned %ld\n",
5826                                 PTR_ERR(rdev));
5827                         return PTR_ERR(rdev);
5828                 }
5829                 rdev->desc_nr = info->number;
5830                 if (info->raid_disk < mddev->raid_disks)
5831                         rdev->raid_disk = info->raid_disk;
5832                 else
5833                         rdev->raid_disk = -1;
5834 
5835                 if (rdev->raid_disk < mddev->raid_disks)
5836                         if (info->state & (1<<MD_DISK_SYNC))
5837                                 set_bit(In_sync, &rdev->flags);
5838 
5839                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5840                         set_bit(WriteMostly, &rdev->flags);
5841 
5842                 if (!mddev->persistent) {
5843                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
5844                         rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5845                 } else
5846                         rdev->sb_start = calc_dev_sboffset(rdev);
5847                 rdev->sectors = rdev->sb_start;
5848 
5849                 err = bind_rdev_to_array(rdev, mddev);
5850                 if (err) {
5851                         export_rdev(rdev);
5852                         return err;
5853                 }
5854         }
5855 
5856         return 0;
5857 }
5858 
5859 static int hot_remove_disk(struct mddev * mddev, dev_t dev)
5860 {
5861         char b[BDEVNAME_SIZE];
5862         struct md_rdev *rdev;
5863 
5864         rdev = find_rdev(mddev, dev);
5865         if (!rdev)
5866                 return -ENXIO;
5867 
5868         clear_bit(Blocked, &rdev->flags);
5869         remove_and_add_spares(mddev, rdev);
5870 
5871         if (rdev->raid_disk >= 0)
5872                 goto busy;
5873 
5874         kick_rdev_from_array(rdev);
5875         md_update_sb(mddev, 1);
5876         md_new_event(mddev);
5877 
5878         return 0;
5879 busy:
5880         printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5881                 bdevname(rdev->bdev,b), mdname(mddev));
5882         return -EBUSY;
5883 }
5884 
5885 static int hot_add_disk(struct mddev * mddev, dev_t dev)
5886 {
5887         char b[BDEVNAME_SIZE];
5888         int err;
5889         struct md_rdev *rdev;
5890 
5891         if (!mddev->pers)
5892                 return -ENODEV;
5893 
5894         if (mddev->major_version != 0) {
5895                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5896                         " version-0 superblocks.\n",
5897                         mdname(mddev));
5898                 return -EINVAL;
5899         }
5900         if (!mddev->pers->hot_add_disk) {
5901                 printk(KERN_WARNING 
5902                         "%s: personality does not support diskops!\n",
5903                         mdname(mddev));
5904                 return -EINVAL;
5905         }
5906 
5907         rdev = md_import_device(dev, -1, 0);
5908         if (IS_ERR(rdev)) {
5909                 printk(KERN_WARNING 
5910                         "md: error, md_import_device() returned %ld\n",
5911                         PTR_ERR(rdev));
5912                 return -EINVAL;
5913         }
5914 
5915         if (mddev->persistent)
5916                 rdev->sb_start = calc_dev_sboffset(rdev);
5917         else
5918                 rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5919 
5920         rdev->sectors = rdev->sb_start;
5921 
5922         if (test_bit(Faulty, &rdev->flags)) {
5923                 printk(KERN_WARNING 
5924                         "md: can not hot-add faulty %s disk to %s!\n",
5925                         bdevname(rdev->bdev,b), mdname(mddev));
5926                 err = -EINVAL;
5927                 goto abort_export;
5928         }
5929         clear_bit(In_sync, &rdev->flags);
5930         rdev->desc_nr = -1;
5931         rdev->saved_raid_disk = -1;
5932         err = bind_rdev_to_array(rdev, mddev);
5933         if (err)
5934                 goto abort_export;
5935 
5936         /*
5937          * The rest should better be atomic, we can have disk failures
5938          * noticed in interrupt contexts ...
5939          */
5940 
5941         rdev->raid_disk = -1;
5942 
5943         md_update_sb(mddev, 1);
5944 
5945         /*
5946          * Kick recovery, maybe this spare has to be added to the
5947          * array immediately.
5948          */
5949         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5950         md_wakeup_thread(mddev->thread);
5951         md_new_event(mddev);
5952         return 0;
5953 
5954 abort_export:
5955         export_rdev(rdev);
5956         return err;
5957 }
5958 
5959 static int set_bitmap_file(struct mddev *mddev, int fd)
5960 {
5961         int err = 0;
5962 
5963         if (mddev->pers) {
5964                 if (!mddev->pers->quiesce || !mddev->thread)
5965                         return -EBUSY;
5966                 if (mddev->recovery || mddev->sync_thread)
5967                         return -EBUSY;
5968                 /* we should be able to change the bitmap.. */
5969         }
5970 
5971 
5972         if (fd >= 0) {
5973                 struct inode *inode;
5974                 if (mddev->bitmap)
5975                         return -EEXIST; /* cannot add when bitmap is present */
5976                 mddev->bitmap_info.file = fget(fd);
5977 
5978                 if (mddev->bitmap_info.file == NULL) {
5979                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5980                                mdname(mddev));
5981                         return -EBADF;
5982                 }
5983 
5984                 inode = mddev->bitmap_info.file->f_mapping->host;
5985                 if (!S_ISREG(inode->i_mode)) {
5986                         printk(KERN_ERR "%s: error: bitmap file must be a regular file\n",
5987                                mdname(mddev));
5988                         err = -EBADF;
5989                 } else if (!(mddev->bitmap_info.file->f_mode & FMODE_WRITE)) {
5990                         printk(KERN_ERR "%s: error: bitmap file must open for write\n",
5991                                mdname(mddev));
5992                         err = -EBADF;
5993                 } else if (atomic_read(&inode->i_writecount) != 1) {
5994                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5995                                mdname(mddev));
5996                         err = -EBUSY;
5997                 }
5998                 if (err) {
5999                         fput(mddev->bitmap_info.file);
6000                         mddev->bitmap_info.file = NULL;
6001                         return err;
6002                 }
6003                 mddev->bitmap_info.offset = 0; /* file overrides offset */
6004         } else if (mddev->bitmap == NULL)
6005                 return -ENOENT; /* cannot remove what isn't there */
6006         err = 0;
6007         if (mddev->pers) {
6008                 mddev->pers->quiesce(mddev, 1);
6009                 if (fd >= 0) {
6010                         err = bitmap_create(mddev);
6011                         if (!err)
6012                                 err = bitmap_load(mddev);
6013                 }
6014                 if (fd < 0 || err) {
6015                         bitmap_destroy(mddev);
6016                         fd = -1; /* make sure to put the file */
6017                 }
6018                 mddev->pers->quiesce(mddev, 0);
6019         }
6020         if (fd < 0) {
6021                 if (mddev->bitmap_info.file)
6022                         fput(mddev->bitmap_info.file);
6023                 mddev->bitmap_info.file = NULL;
6024         }
6025 
6026         return err;
6027 }
6028 
6029 /*
6030  * set_array_info is used two different ways
6031  * The original usage is when creating a new array.
6032  * In this usage, raid_disks is > 0 and it together with
6033  *  level, size, not_persistent,layout,chunksize determine the
6034  *  shape of the array.
6035  *  This will always create an array with a type-0.90.0 superblock.
6036  * The newer usage is when assembling an array.
6037  *  In this case raid_disks will be 0, and the major_version field is
6038  *  use to determine which style super-blocks are to be found on the devices.
6039  *  The minor and patch _version numbers are also kept incase the
6040  *  super_block handler wishes to interpret them.
6041  */
6042 static int set_array_info(struct mddev * mddev, mdu_array_info_t *info)
6043 {
6044 
6045         if (info->raid_disks == 0) {
6046                 /* just setting version number for superblock loading */
6047                 if (info->major_version < 0 ||
6048                     info->major_version >= ARRAY_SIZE(super_types) ||
6049                     super_types[info->major_version].name == NULL) {
6050                         /* maybe try to auto-load a module? */
6051                         printk(KERN_INFO 
6052                                 "md: superblock version %d not known\n",
6053                                 info->major_version);
6054                         return -EINVAL;
6055                 }
6056                 mddev->major_version = info->major_version;
6057                 mddev->minor_version = info->minor_version;
6058                 mddev->patch_version = info->patch_version;
6059                 mddev->persistent = !info->not_persistent;
6060                 /* ensure mddev_put doesn't delete this now that there
6061                  * is some minimal configuration.
6062                  */
6063                 mddev->ctime         = get_seconds();
6064                 return 0;
6065         }
6066         mddev->major_version = MD_MAJOR_VERSION;
6067         mddev->minor_version = MD_MINOR_VERSION;
6068         mddev->patch_version = MD_PATCHLEVEL_VERSION;
6069         mddev->ctime         = get_seconds();
6070 
6071         mddev->level         = info->level;
6072         mddev->clevel[0]     = 0;
6073         mddev->dev_sectors   = 2 * (sector_t)info->size;
6074         mddev->raid_disks    = info->raid_disks;
6075         /* don't set md_minor, it is determined by which /dev/md* was
6076          * openned
6077          */
6078         if (info->state & (1<<MD_SB_CLEAN))
6079                 mddev->recovery_cp = MaxSector;
6080         else
6081                 mddev->recovery_cp = 0;
6082         mddev->persistent    = ! info->not_persistent;
6083         mddev->external      = 0;
6084 
6085         mddev->layout        = info->layout;
6086         mddev->chunk_sectors = info->chunk_size >> 9;
6087 
6088         mddev->max_disks     = MD_SB_DISKS;
6089 
6090         if (mddev->persistent)
6091                 mddev->flags         = 0;
6092         set_bit(MD_CHANGE_DEVS, &mddev->flags);
6093 
6094         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6095         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6096         mddev->bitmap_info.offset = 0;
6097 
6098         mddev->reshape_position = MaxSector;
6099 
6100         /*
6101          * Generate a 128 bit UUID
6102          */
6103         get_random_bytes(mddev->uuid, 16);
6104 
6105         mddev->new_level = mddev->level;
6106         mddev->new_chunk_sectors = mddev->chunk_sectors;
6107         mddev->new_layout = mddev->layout;
6108         mddev->delta_disks = 0;
6109         mddev->reshape_backwards = 0;
6110 
6111         return 0;
6112 }
6113 
6114 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6115 {
6116         WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6117 
6118         if (mddev->external_size)
6119                 return;
6120 
6121         mddev->array_sectors = array_sectors;
6122 }
6123 EXPORT_SYMBOL(md_set_array_sectors);
6124 
6125 static int update_size(struct mddev *mddev, sector_t num_sectors)
6126 {
6127         struct md_rdev *rdev;
6128         int rv;
6129         int fit = (num_sectors == 0);
6130 
6131         if (mddev->pers->resize == NULL)
6132                 return -EINVAL;
6133         /* The "num_sectors" is the number of sectors of each device that
6134          * is used.  This can only make sense for arrays with redundancy.
6135          * linear and raid0 always use whatever space is available. We can only
6136          * consider changing this number if no resync or reconstruction is
6137          * happening, and if the new size is acceptable. It must fit before the
6138          * sb_start or, if that is <data_offset, it must fit before the size
6139          * of each device.  If num_sectors is zero, we find the largest size
6140          * that fits.
6141          */
6142         if (mddev->sync_thread)
6143                 return -EBUSY;
6144         if (mddev->ro)
6145                 return -EROFS;
6146 
6147         rdev_for_each(rdev, mddev) {
6148                 sector_t avail = rdev->sectors;
6149 
6150                 if (fit && (num_sectors == 0 || num_sectors > avail))
6151                         num_sectors = avail;
6152                 if (avail < num_sectors)
6153                         return -ENOSPC;
6154         }
6155         rv = mddev->pers->resize(mddev, num_sectors);
6156         if (!rv)
6157                 revalidate_disk(mddev->gendisk);
6158         return rv;
6159 }
6160 
6161 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6162 {
6163         int rv;
6164         struct md_rdev *rdev;
6165         /* change the number of raid disks */
6166         if (mddev->pers->check_reshape == NULL)
6167                 return -EINVAL;
6168         if (mddev->ro)
6169                 return -EROFS;
6170         if (raid_disks <= 0 ||
6171             (mddev->max_disks && raid_disks >= mddev->max_disks))
6172                 return -EINVAL;
6173         if (mddev->sync_thread || mddev->reshape_position != MaxSector)
6174                 return -EBUSY;
6175 
6176         rdev_for_each(rdev, mddev) {
6177                 if (mddev->raid_disks < raid_disks &&
6178                     rdev->data_offset < rdev->new_data_offset)
6179                         return -EINVAL;
6180                 if (mddev->raid_disks > raid_disks &&
6181                     rdev->data_offset > rdev->new_data_offset)
6182                         return -EINVAL;
6183         }
6184 
6185         mddev->delta_disks = raid_disks - mddev->raid_disks;
6186         if (mddev->delta_disks < 0)
6187                 mddev->reshape_backwards = 1;
6188         else if (mddev->delta_disks > 0)
6189                 mddev->reshape_backwards = 0;
6190 
6191         rv = mddev->pers->check_reshape(mddev);
6192         if (rv < 0) {
6193                 mddev->delta_disks = 0;
6194                 mddev->reshape_backwards = 0;
6195         }
6196         return rv;
6197 }
6198 
6199 
6200 /*
6201  * update_array_info is used to change the configuration of an
6202  * on-line array.
6203  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6204  * fields in the info are checked against the array.
6205  * Any differences that cannot be handled will cause an error.
6206  * Normally, only one change can be managed at a time.
6207  */
6208 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6209 {
6210         int rv = 0;
6211         int cnt = 0;
6212         int state = 0;
6213 
6214         /* calculate expected state,ignoring low bits */
6215         if (mddev->bitmap && mddev->bitmap_info.offset)
6216                 state |= (1 << MD_SB_BITMAP_PRESENT);
6217 
6218         if (mddev->major_version != info->major_version ||
6219             mddev->minor_version != info->minor_version ||
6220 /*          mddev->patch_version != info->patch_version || */
6221             mddev->ctime         != info->ctime         ||
6222             mddev->level         != info->level         ||
6223 /*          mddev->layout        != info->layout        || */
6224             !mddev->persistent   != info->not_persistent||
6225             mddev->chunk_sectors != info->chunk_size >> 9 ||
6226             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6227             ((state^info->state) & 0xfffffe00)
6228                 )
6229                 return -EINVAL;
6230         /* Check there is only one change */
6231         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6232                 cnt++;
6233         if (mddev->raid_disks != info->raid_disks)
6234                 cnt++;
6235         if (mddev->layout != info->layout)
6236                 cnt++;
6237         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6238                 cnt++;
6239         if (cnt == 0)
6240                 return 0;
6241         if (cnt > 1)
6242                 return -EINVAL;
6243 
6244         if (mddev->layout != info->layout) {
6245                 /* Change layout
6246                  * we don't need to do anything at the md level, the
6247                  * personality will take care of it all.
6248                  */
6249                 if (mddev->pers->check_reshape == NULL)
6250                         return -EINVAL;
6251                 else {
6252                         mddev->new_layout = info->layout;
6253                         rv = mddev->pers->check_reshape(mddev);
6254                         if (rv)
6255                                 mddev->new_layout = mddev->layout;
6256                         return rv;
6257                 }
6258         }
6259         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6260                 rv = update_size(mddev, (sector_t)info->size * 2);
6261 
6262         if (mddev->raid_disks    != info->raid_disks)
6263                 rv = update_raid_disks(mddev, info->raid_disks);
6264 
6265         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6266                 if (mddev->pers->quiesce == NULL || mddev->thread == NULL)
6267                         return -EINVAL;
6268                 if (mddev->recovery || mddev->sync_thread)
6269                         return -EBUSY;
6270                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6271                         /* add the bitmap */
6272                         if (mddev->bitmap)
6273                                 return -EEXIST;
6274                         if (mddev->bitmap_info.default_offset == 0)
6275                                 return -EINVAL;
6276                         mddev->bitmap_info.offset =
6277                                 mddev->bitmap_info.default_offset;
6278                         mddev->bitmap_info.space =
6279                                 mddev->bitmap_info.default_space;
6280                         mddev->pers->quiesce(mddev, 1);
6281                         rv = bitmap_create(mddev);
6282                         if (!rv)
6283                                 rv = bitmap_load(mddev);
6284                         if (rv)
6285                                 bitmap_destroy(mddev);
6286                         mddev->pers->quiesce(mddev, 0);
6287                 } else {
6288                         /* remove the bitmap */
6289                         if (!mddev->bitmap)
6290                                 return -ENOENT;
6291                         if (mddev->bitmap->storage.file)
6292                                 return -EINVAL;
6293                         mddev->pers->quiesce(mddev, 1);
6294                         bitmap_destroy(mddev);
6295                         mddev->pers->quiesce(mddev, 0);
6296                         mddev->bitmap_info.offset = 0;
6297                 }
6298         }
6299         md_update_sb(mddev, 1);
6300         return rv;
6301 }
6302 
6303 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6304 {
6305         struct md_rdev *rdev;
6306         int err = 0;
6307 
6308         if (mddev->pers == NULL)
6309                 return -ENODEV;
6310 
6311         rcu_read_lock();
6312         rdev = find_rdev_rcu(mddev, dev);
6313         if (!rdev)
6314                 err =  -ENODEV;
6315         else {
6316                 md_error(mddev, rdev);
6317                 if (!test_bit(Faulty, &rdev->flags))
6318                         err = -EBUSY;
6319         }
6320         rcu_read_unlock();
6321         return err;
6322 }
6323 
6324 /*
6325  * We have a problem here : there is no easy way to give a CHS
6326  * virtual geometry. We currently pretend that we have a 2 heads
6327  * 4 sectors (with a BIG number of cylinders...). This drives
6328  * dosfs just mad... ;-)
6329  */
6330 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6331 {
6332         struct mddev *mddev = bdev->bd_disk->private_data;
6333 
6334         geo->heads = 2;
6335         geo->sectors = 4;
6336         geo->cylinders = mddev->array_sectors / 8;
6337         return 0;
6338 }
6339 
6340 static inline bool md_ioctl_valid(unsigned int cmd)
6341 {
6342         switch (cmd) {
6343         case ADD_NEW_DISK:
6344         case BLKROSET:
6345         case GET_ARRAY_INFO:
6346         case GET_BITMAP_FILE:
6347         case GET_DISK_INFO:
6348         case HOT_ADD_DISK:
6349         case HOT_REMOVE_DISK:
6350         case PRINT_RAID_DEBUG:
6351         case RAID_AUTORUN:
6352         case RAID_VERSION:
6353         case RESTART_ARRAY_RW:
6354         case RUN_ARRAY:
6355         case SET_ARRAY_INFO:
6356         case SET_BITMAP_FILE:
6357         case SET_DISK_FAULTY:
6358         case STOP_ARRAY:
6359         case STOP_ARRAY_RO:
6360                 return true;
6361         default:
6362                 return false;
6363         }
6364 }
6365 
6366 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6367                         unsigned int cmd, unsigned long arg)
6368 {
6369         int err = 0;
6370         void __user *argp = (void __user *)arg;
6371         struct mddev *mddev = NULL;
6372         int ro;
6373 
6374         if (!md_ioctl_valid(cmd))
6375                 return -ENOTTY;
6376 
6377         switch (cmd) {
6378         case RAID_VERSION:
6379         case GET_ARRAY_INFO:
6380         case GET_DISK_INFO:
6381                 break;
6382         default:
6383                 if (!capable(CAP_SYS_ADMIN))
6384                         return -EACCES;
6385         }
6386 
6387         /*
6388          * Commands dealing with the RAID driver but not any
6389          * particular array:
6390          */
6391         switch (cmd) {
6392         case RAID_VERSION:
6393                 err = get_version(argp);
6394                 goto done;
6395 
6396         case PRINT_RAID_DEBUG:
6397                 err = 0;
6398                 md_print_devices();
6399                 goto done;
6400 
6401 #ifndef MODULE
6402         case RAID_AUTORUN:
6403                 err = 0;
6404                 autostart_arrays(arg);
6405                 goto done;
6406 #endif
6407         default:;
6408         }
6409 
6410         /*
6411          * Commands creating/starting a new array:
6412          */
6413 
6414         mddev = bdev->bd_disk->private_data;
6415 
6416         if (!mddev) {
6417                 BUG();
6418                 goto abort;
6419         }
6420 
6421         /* Some actions do not requires the mutex */
6422         switch (cmd) {
6423         case GET_ARRAY_INFO:
6424                 if (!mddev->raid_disks && !mddev->external)
6425                         err = -ENODEV;
6426                 else
6427                         err = get_array_info(mddev, argp);
6428                 goto abort;
6429 
6430         case GET_DISK_INFO:
6431                 if (!mddev->raid_disks && !mddev->external)
6432                         err = -ENODEV;
6433                 else
6434                         err = get_disk_info(mddev, argp);
6435                 goto abort;
6436 
6437         case SET_DISK_FAULTY:
6438                 err = set_disk_faulty(mddev, new_decode_dev(arg));
6439                 goto abort;
6440         }
6441 
6442         if (cmd == ADD_NEW_DISK)
6443                 /* need to ensure md_delayed_delete() has completed */
6444                 flush_workqueue(md_misc_wq);
6445 
6446         if (cmd == HOT_REMOVE_DISK)
6447                 /* need to ensure recovery thread has run */
6448                 wait_event_interruptible_timeout(mddev->sb_wait,
6449                                                  !test_bit(MD_RECOVERY_NEEDED,
6450                                                            &mddev->flags),
6451                                                  msecs_to_jiffies(5000));
6452         if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
6453                 /* Need to flush page cache, and ensure no-one else opens
6454                  * and writes
6455                  */
6456                 mutex_lock(&mddev->open_mutex);
6457                 if (atomic_read(&mddev->openers) > 1) {
6458                         mutex_unlock(&mddev->open_mutex);
6459                         err = -EBUSY;
6460                         goto abort;
6461                 }
6462                 set_bit(MD_STILL_CLOSED, &mddev->flags);
6463                 mutex_unlock(&mddev->open_mutex);
6464                 sync_blockdev(bdev);
6465         }
6466         err = mddev_lock(mddev);
6467         if (err) {
6468                 printk(KERN_INFO 
6469                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
6470                         err, cmd);
6471                 goto abort;
6472         }
6473 
6474         if (cmd == SET_ARRAY_INFO) {
6475                 mdu_array_info_t info;
6476                 if (!arg)
6477                         memset(&info, 0, sizeof(info));
6478                 else if (copy_from_user(&info, argp, sizeof(info))) {
6479                         err = -EFAULT;
6480                         goto abort_unlock;
6481                 }
6482                 if (mddev->pers) {
6483                         err = update_array_info(mddev, &info);
6484                         if (err) {
6485                                 printk(KERN_WARNING "md: couldn't update"
6486                                        " array info. %d\n", err);
6487                                 goto abort_unlock;
6488                         }
6489                         goto done_unlock;
6490                 }
6491                 if (!list_empty(&mddev->disks)) {
6492                         printk(KERN_WARNING
6493                                "md: array %s already has disks!\n",
6494                                mdname(mddev));
6495                         err = -EBUSY;
6496                         goto abort_unlock;
6497                 }
6498                 if (mddev->raid_disks) {
6499                         printk(KERN_WARNING
6500                                "md: array %s already initialised!\n",
6501                                mdname(mddev));
6502                         err = -EBUSY;
6503                         goto abort_unlock;
6504                 }
6505                 err = set_array_info(mddev, &info);
6506                 if (err) {
6507                         printk(KERN_WARNING "md: couldn't set"
6508                                " array info. %d\n", err);
6509                         goto abort_unlock;
6510                 }
6511                 goto done_unlock;
6512         }
6513 
6514         /*
6515          * Commands querying/configuring an existing array:
6516          */
6517         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6518          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6519         if ((!mddev->raid_disks && !mddev->external)
6520             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6521             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6522             && cmd != GET_BITMAP_FILE) {
6523                 err = -ENODEV;
6524                 goto abort_unlock;
6525         }
6526 
6527         /*
6528          * Commands even a read-only array can execute:
6529          */
6530         switch (cmd) {
6531         case GET_BITMAP_FILE:
6532                 err = get_bitmap_file(mddev, argp);
6533                 goto done_unlock;
6534 
6535         case RESTART_ARRAY_RW:
6536                 err = restart_array(mddev);
6537                 goto done_unlock;
6538 
6539         case STOP_ARRAY:
6540                 err = do_md_stop(mddev, 0, bdev);
6541                 goto done_unlock;
6542 
6543         case STOP_ARRAY_RO:
6544                 err = md_set_readonly(mddev, bdev);
6545                 goto done_unlock;
6546 
6547         case HOT_REMOVE_DISK:
6548                 err = hot_remove_disk(mddev, new_decode_dev(arg));
6549                 goto done_unlock;
6550 
6551         case ADD_NEW_DISK:
6552                 /* We can support ADD_NEW_DISK on read-only arrays
6553                  * on if we are re-adding a preexisting device.
6554                  * So require mddev->pers and MD_DISK_SYNC.
6555                  */
6556                 if (mddev->pers) {
6557                         mdu_disk_info_t info;
6558                         if (copy_from_user(&info, argp, sizeof(info)))
6559                                 err = -EFAULT;
6560                         else if (!(info.state & (1<<MD_DISK_SYNC)))
6561                                 /* Need to clear read-only for this */
6562                                 break;
6563                         else
6564                                 err = add_new_disk(mddev, &info);
6565                         goto done_unlock;
6566                 }
6567                 break;
6568 
6569         case BLKROSET:
6570                 if (get_user(ro, (int __user *)(arg))) {
6571                         err = -EFAULT;
6572                         goto done_unlock;
6573                 }
6574                 err = -EINVAL;
6575 
6576                 /* if the bdev is going readonly the value of mddev->ro
6577                  * does not matter, no writes are coming
6578                  */
6579                 if (ro)
6580                         goto done_unlock;
6581 
6582                 /* are we are already prepared for writes? */
6583                 if (mddev->ro != 1)
6584                         goto done_unlock;
6585 
6586                 /* transitioning to readauto need only happen for
6587                  * arrays that call md_write_start
6588                  */
6589                 if (mddev->pers) {
6590                         err = restart_array(mddev);
6591                         if (err == 0) {
6592                                 mddev->ro = 2;
6593                                 set_disk_ro(mddev->gendisk, 0);
6594                         }
6595                 }
6596                 goto done_unlock;
6597         }
6598 
6599         /*
6600          * The remaining ioctls are changing the state of the
6601          * superblock, so we do not allow them on read-only arrays.
6602          * However non-MD ioctls (e.g. get-size) will still come through
6603          * here and hit the 'default' below, so only disallow
6604          * 'md' ioctls, and switch to rw mode if started auto-readonly.
6605          */
6606         if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6607                 if (mddev->ro == 2) {
6608                         mddev->ro = 0;
6609                         sysfs_notify_dirent_safe(mddev->sysfs_state);
6610                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6611                         /* mddev_unlock will wake thread */
6612                         /* If a device failed while we were read-only, we
6613                          * need to make sure the metadata is updated now.
6614                          */
6615                         if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
6616                                 mddev_unlock(mddev);
6617                                 wait_event(mddev->sb_wait,
6618                                            !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
6619                                            !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6620                                 mddev_lock_nointr(mddev);
6621                         }
6622                 } else {
6623                         err = -EROFS;
6624                         goto abort_unlock;
6625                 }
6626         }
6627 
6628         switch (cmd) {
6629         case ADD_NEW_DISK:
6630         {
6631                 mdu_disk_info_t info;
6632                 if (copy_from_user(&info, argp, sizeof(info)))
6633                         err = -EFAULT;
6634                 else
6635                         err = add_new_disk(mddev, &info);
6636                 goto done_unlock;
6637         }
6638 
6639         case HOT_ADD_DISK:
6640                 err = hot_add_disk(mddev, new_decode_dev(arg));
6641                 goto done_unlock;
6642 
6643         case RUN_ARRAY:
6644                 err = do_md_run(mddev);
6645                 goto done_unlock;
6646 
6647         case SET_BITMAP_FILE:
6648                 err = set_bitmap_file(mddev, (int)arg);
6649                 goto done_unlock;
6650 
6651         default:
6652                 err = -EINVAL;
6653                 goto abort_unlock;
6654         }
6655 
6656 done_unlock:
6657 abort_unlock:
6658         if (mddev->hold_active == UNTIL_IOCTL &&
6659             err != -EINVAL)
6660                 mddev->hold_active = 0;
6661         mddev_unlock(mddev);
6662 
6663         return err;
6664 done:
6665         if (err)
6666                 MD_BUG();
6667 abort:
6668         return err;
6669 }
6670 #ifdef CONFIG_COMPAT
6671 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6672                     unsigned int cmd, unsigned long arg)
6673 {
6674         switch (cmd) {
6675         case HOT_REMOVE_DISK:
6676         case HOT_ADD_DISK:
6677         case SET_DISK_FAULTY:
6678         case SET_BITMAP_FILE:
6679                 /* These take in integer arg, do not convert */
6680                 break;
6681         default:
6682                 arg = (unsigned long)compat_ptr(arg);
6683                 break;
6684         }
6685 
6686         return md_ioctl(bdev, mode, cmd, arg);
6687 }
6688 #endif /* CONFIG_COMPAT */
6689 
6690 static int md_open(struct block_device *bdev, fmode_t mode)
6691 {
6692         /*
6693          * Succeed if we can lock the mddev, which confirms that
6694          * it isn't being stopped right now.
6695          */
6696         struct mddev *mddev = mddev_find(bdev->bd_dev);
6697         int err;
6698 
6699         if (!mddev)
6700                 return -ENODEV;
6701 
6702         if (mddev->gendisk != bdev->bd_disk) {
6703                 /* we are racing with mddev_put which is discarding this
6704                  * bd_disk.
6705                  */
6706                 mddev_put(mddev);
6707                 /* Wait until bdev->bd_disk is definitely gone */
6708                 flush_workqueue(md_misc_wq);
6709                 /* Then retry the open from the top */
6710                 return -ERESTARTSYS;
6711         }
6712         BUG_ON(mddev != bdev->bd_disk->private_data);
6713 
6714         if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6715                 goto out;
6716 
6717         err = 0;
6718         atomic_inc(&mddev->openers);
6719         clear_bit(MD_STILL_CLOSED, &mddev->flags);
6720         mutex_unlock(&mddev->open_mutex);
6721 
6722         check_disk_change(bdev);
6723  out:
6724         return err;
6725 }
6726 
6727 static void md_release(struct gendisk *disk, fmode_t mode)
6728 {
6729         struct mddev *mddev = disk->private_data;
6730 
6731         BUG_ON(!mddev);
6732         atomic_dec(&mddev->openers);
6733         mddev_put(mddev);
6734 }
6735 
6736 static int md_media_changed(struct gendisk *disk)
6737 {
6738         struct mddev *mddev = disk->private_data;
6739 
6740         return mddev->changed;
6741 }
6742 
6743 static int md_revalidate(struct gendisk *disk)
6744 {
6745         struct mddev *mddev = disk->private_data;
6746 
6747         mddev->changed = 0;
6748         return 0;
6749 }
6750 static const struct block_device_operations md_fops =
6751 {
6752         .owner          = THIS_MODULE,
6753         .open           = md_open,
6754         .release        = md_release,
6755         .ioctl          = md_ioctl,
6756 #ifdef CONFIG_COMPAT
6757         .compat_ioctl   = md_compat_ioctl,
6758 #endif
6759         .getgeo         = md_getgeo,
6760         .media_changed  = md_media_changed,
6761         .revalidate_disk= md_revalidate,
6762 };
6763 
6764 static int md_thread(void * arg)
6765 {
6766         struct md_thread *thread = arg;
6767 
6768         /*
6769          * md_thread is a 'system-thread', it's priority should be very
6770          * high. We avoid resource deadlocks individually in each
6771          * raid personality. (RAID5 does preallocation) We also use RR and
6772          * the very same RT priority as kswapd, thus we will never get
6773          * into a priority inversion deadlock.
6774          *
6775          * we definitely have to have equal or higher priority than
6776          * bdflush, otherwise bdflush will deadlock if there are too
6777          * many dirty RAID5 blocks.
6778          */
6779 
6780         allow_signal(SIGKILL);
6781         while (!kthread_should_stop()) {
6782 
6783                 /* We need to wait INTERRUPTIBLE so that
6784                  * we don't add to the load-average.
6785                  * That means we need to be sure no signals are
6786                  * pending
6787                  */
6788                 if (signal_pending(current))
6789                         flush_signals(current);
6790 
6791                 wait_event_interruptible_timeout
6792                         (thread->wqueue,
6793                          test_bit(THREAD_WAKEUP, &thread->flags)
6794                          || kthread_should_stop(),
6795                          thread->timeout);
6796 
6797                 clear_bit(THREAD_WAKEUP, &thread->flags);
6798                 if (!kthread_should_stop())
6799                         thread->run(thread);
6800         }
6801 
6802         return 0;
6803 }
6804 
6805 void md_wakeup_thread(struct md_thread *thread)
6806 {
6807         if (thread) {
6808                 pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
6809                 set_bit(THREAD_WAKEUP, &thread->flags);
6810                 wake_up(&thread->wqueue);
6811         }
6812 }
6813 
6814 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
6815                 struct mddev *mddev, const char *name)
6816 {
6817         struct md_thread *thread;
6818 
6819         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
6820         if (!thread)
6821                 return NULL;
6822 
6823         init_waitqueue_head(&thread->wqueue);
6824 
6825         thread->run = run;
6826         thread->mddev = mddev;
6827         thread->timeout = MAX_SCHEDULE_TIMEOUT;
6828         thread->tsk = kthread_run(md_thread, thread,
6829                                   "%s_%s",
6830                                   mdname(thread->mddev),
6831                                   name);
6832         if (IS_ERR(thread->tsk)) {
6833                 kfree(thread);
6834                 return NULL;
6835         }
6836         return thread;
6837 }
6838 
6839 void md_unregister_thread(struct md_thread **threadp)
6840 {
6841         struct md_thread *thread = *threadp;
6842         if (!thread)
6843                 return;
6844         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6845         /* Locking ensures that mddev_unlock does not wake_up a
6846          * non-existent thread
6847          */
6848         spin_lock(&pers_lock);
6849         *threadp = NULL;
6850         spin_unlock(&pers_lock);
6851 
6852         kthread_stop(thread->tsk);
6853         kfree(thread);
6854 }
6855 
6856 void md_error(struct mddev *mddev, struct md_rdev *rdev)
6857 {
6858         if (!mddev) {
6859                 MD_BUG();
6860                 return;
6861         }
6862 
6863         if (!rdev || test_bit(Faulty, &rdev->flags))
6864                 return;
6865 
6866         if (!mddev->pers || !mddev->pers->error_handler)
6867                 return;
6868         mddev->pers->error_handler(mddev,rdev);
6869         if (mddev->degraded)
6870                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6871         sysfs_notify_dirent_safe(rdev->sysfs_state);
6872         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6873         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6874         md_wakeup_thread(mddev->thread);
6875         if (mddev->event_work.func)
6876                 queue_work(md_misc_wq, &mddev->event_work);
6877         md_new_event_inintr(mddev);
6878 }
6879 
6880 /* seq_file implementation /proc/mdstat */
6881 
6882 static void status_unused(struct seq_file *seq)
6883 {
6884         int i = 0;
6885         struct md_rdev *rdev;
6886 
6887         seq_printf(seq, "unused devices: ");
6888 
6889         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6890                 char b[BDEVNAME_SIZE];
6891                 i++;
6892                 seq_printf(seq, "%s ",
6893                               bdevname(rdev->bdev,b));
6894         }
6895         if (!i)
6896                 seq_printf(seq, "<none>");
6897 
6898         seq_printf(seq, "\n");
6899 }
6900 
6901 
6902 static void status_resync(struct seq_file *seq, struct mddev * mddev)
6903 {
6904         sector_t max_sectors, resync, res;
6905         unsigned long dt, db;
6906         sector_t rt;
6907         int scale;
6908         unsigned int per_milli;
6909 
6910         if (mddev->curr_resync <= 3)
6911                 resync = 0;
6912         else
6913                 resync = mddev->curr_resync
6914                         - atomic_read(&mddev->recovery_active);
6915 
6916         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
6917             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6918                 max_sectors = mddev->resync_max_sectors;
6919         else
6920                 max_sectors = mddev->dev_sectors;
6921 
6922         /*
6923          * Should not happen.
6924          */
6925         if (!max_sectors) {
6926                 MD_BUG();
6927                 return;
6928         }
6929         /* Pick 'scale' such that (resync>>scale)*1000 will fit
6930          * in a sector_t, and (max_sectors>>scale) will fit in a
6931          * u32, as those are the requirements for sector_div.
6932          * Thus 'scale' must be at least 10
6933          */
6934         scale = 10;
6935         if (sizeof(sector_t) > sizeof(unsigned long)) {
6936                 while ( max_sectors/2 > (1ULL<<(scale+32)))
6937                         scale++;
6938         }
6939         res = (resync>>scale)*1000;
6940         sector_div(res, (u32)((max_sectors>>scale)+1));
6941 
6942         per_milli = res;
6943         {
6944                 int i, x = per_milli/50, y = 20-x;
6945                 seq_printf(seq, "[");
6946                 for (i = 0; i < x; i++)
6947                         seq_printf(seq, "=");
6948                 seq_printf(seq, ">");
6949                 for (i = 0; i < y; i++)
6950                         seq_printf(seq, ".");
6951                 seq_printf(seq, "] ");
6952         }
6953         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6954                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6955                     "reshape" :
6956                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6957                      "check" :
6958                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6959                       "resync" : "recovery"))),
6960                    per_milli/10, per_milli % 10,
6961                    (unsigned long long) resync/2,
6962                    (unsigned long long) max_sectors/2);
6963 
6964         /*
6965          * dt: time from mark until now
6966          * db: blocks written from mark until now
6967          * rt: remaining time
6968          *
6969          * rt is a sector_t, so could be 32bit or 64bit.
6970          * So we divide before multiply in case it is 32bit and close
6971          * to the limit.
6972          * We scale the divisor (db) by 32 to avoid losing precision
6973          * near the end of resync when the number of remaining sectors
6974          * is close to 'db'.
6975          * We then divide rt by 32 after multiplying by db to compensate.
6976          * The '+1' avoids division by zero if db is very small.
6977          */
6978         dt = ((jiffies - mddev->resync_mark) / HZ);
6979         if (!dt) dt++;
6980         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6981                 - mddev->resync_mark_cnt;
6982 
6983         rt = max_sectors - resync;    /* number of remaining sectors */
6984         sector_div(rt, db/32+1);
6985         rt *= dt;
6986         rt >>= 5;
6987 
6988         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6989                    ((unsigned long)rt % 60)/6);
6990 
6991         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6992 }
6993 
6994 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6995 {
6996         struct list_head *tmp;
6997         loff_t l = *pos;
6998         struct mddev *mddev;
6999 
7000         if (l >= 0x10000)
7001                 return NULL;
7002         if (!l--)
7003                 /* header */
7004                 return (void*)1;
7005 
7006         spin_lock(&all_mddevs_lock);
7007         list_for_each(tmp,&all_mddevs)
7008                 if (!l--) {
7009                         mddev = list_entry(tmp, struct mddev, all_mddevs);
7010                         mddev_get(mddev);
7011                         spin_unlock(&all_mddevs_lock);
7012                         return mddev;
7013                 }
7014         spin_unlock(&all_mddevs_lock);
7015         if (!l--)
7016                 return (void*)2;/* tail */
7017         return NULL;
7018 }
7019 
7020 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
7021 {
7022         struct list_head *tmp;
7023         struct mddev *next_mddev, *mddev = v;
7024         
7025         ++*pos;
7026         if (v == (void*)2)
7027                 return NULL;
7028 
7029         spin_lock(&all_mddevs_lock);
7030         if (v == (void*)1)
7031                 tmp = all_mddevs.next;
7032         else
7033                 tmp = mddev->all_mddevs.next;
7034         if (tmp != &all_mddevs)
7035                 next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
7036         else {
7037                 next_mddev = (void*)2;
7038                 *pos = 0x10000;
7039         }               
7040         spin_unlock(&all_mddevs_lock);
7041 
7042         if (v != (void*)1)
7043                 mddev_put(mddev);
7044         return next_mddev;
7045 
7046 }
7047 
7048 static void md_seq_stop(struct seq_file *seq, void *v)
7049 {
7050         struct mddev *mddev = v;
7051 
7052         if (mddev && v != (void*)1 && v != (void*)2)
7053                 mddev_put(mddev);
7054 }
7055 
7056 static int md_seq_show(struct seq_file *seq, void *v)
7057 {
7058         struct mddev *mddev = v;
7059         sector_t sectors;
7060         struct md_rdev *rdev;
7061 
7062         if (v == (void*)1) {
7063                 struct md_personality *pers;
7064                 seq_printf(seq, "Personalities : ");
7065                 spin_lock(&pers_lock);
7066                 list_for_each_entry(pers, &pers_list, list)
7067                         seq_printf(seq, "[%s] ", pers->name);
7068 
7069                 spin_unlock(&pers_lock);
7070                 seq_printf(seq, "\n");
7071                 seq->poll_event = atomic_read(&md_event_count);
7072                 return 0;
7073         }
7074         if (v == (void*)2) {
7075                 status_unused(seq);
7076                 return 0;
7077         }
7078 
7079         if (mddev_lock(mddev) < 0)
7080                 return -EINTR;
7081 
7082         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
7083                 seq_printf(seq, "%s : %sactive", mdname(mddev),
7084                                                 mddev->pers ? "" : "in");
7085                 if (mddev->pers) {
7086                         if (mddev->ro==1)
7087                                 seq_printf(seq, " (read-only)");
7088                         if (mddev->ro==2)
7089                                 seq_printf(seq, " (auto-read-only)");
7090                         seq_printf(seq, " %s", mddev->pers->name);
7091                 }
7092 
7093                 sectors = 0;
7094                 rdev_for_each(rdev, mddev) {
7095                         char b[BDEVNAME_SIZE];
7096                         seq_printf(seq, " %s[%d]",
7097                                 bdevname(rdev->bdev,b), rdev->desc_nr);
7098                         if (test_bit(WriteMostly, &rdev->flags))
7099                                 seq_printf(seq, "(W)");
7100                         if (test_bit(Faulty, &rdev->flags)) {
7101                                 seq_printf(seq, "(F)");
7102                                 continue;
7103                         }
7104                         if (rdev->raid_disk < 0)
7105                                 seq_printf(seq, "(S)"); /* spare */
7106                         if (test_bit(Replacement, &rdev->flags))
7107                                 seq_printf(seq, "(R)");
7108                         sectors += rdev->sectors;
7109                 }
7110 
7111                 if (!list_empty(&mddev->disks)) {
7112                         if (mddev->pers)
7113                                 seq_printf(seq, "\n      %llu blocks",
7114                                            (unsigned long long)
7115                                            mddev->array_sectors / 2);
7116                         else
7117                                 seq_printf(seq, "\n      %llu blocks",
7118                                            (unsigned long long)sectors / 2);
7119                 }
7120                 if (mddev->persistent) {
7121                         if (mddev->major_version != 0 ||
7122                             mddev->minor_version != 90) {
7123                                 seq_printf(seq," super %d.%d",
7124                                            mddev->major_version,
7125                                            mddev->minor_version);
7126                         }
7127                 } else if (mddev->external)
7128                         seq_printf(seq, " super external:%s",
7129                                    mddev->metadata_type);
7130                 else
7131                         seq_printf(seq, " super non-persistent");
7132 
7133                 if (mddev->pers) {
7134                         mddev->pers->status(seq, mddev);
7135                         seq_printf(seq, "\n      ");
7136                         if (mddev->pers->sync_request) {
7137                                 if (mddev->curr_resync > 2) {
7138                                         status_resync(seq, mddev);
7139                                         seq_printf(seq, "\n      ");
7140                                 } else if (mddev->curr_resync >= 1)
7141                                         seq_printf(seq, "\tresync=DELAYED\n      ");
7142                                 else if (mddev->recovery_cp < MaxSector)
7143                                         seq_printf(seq, "\tresync=PENDING\n      ");
7144                         }
7145                 } else
7146                         seq_printf(seq, "\n       ");
7147 
7148                 bitmap_status(seq, mddev->bitmap);
7149 
7150                 seq_printf(seq, "\n");
7151         }
7152         mddev_unlock(mddev);
7153         
7154         return 0;
7155 }
7156 
7157 static const struct seq_operations md_seq_ops = {
7158         .start  = md_seq_start,
7159         .next   = md_seq_next,
7160         .stop   = md_seq_stop,
7161         .show   = md_seq_show,
7162 };
7163 
7164 static int md_seq_open(struct inode *inode, struct file *file)
7165 {
7166         struct seq_file *seq;
7167         int error;
7168 
7169         error = seq_open(file, &md_seq_ops);
7170         if (error)
7171                 return error;
7172 
7173         seq = file->private_data;
7174         seq->poll_event = atomic_read(&md_event_count);
7175         return error;
7176 }
7177 
7178 static int md_unloading;
7179 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7180 {
7181         struct seq_file *seq = filp->private_data;
7182         int mask;
7183 
7184         if (md_unloading)
7185                 return POLLIN|POLLRDNORM|POLLERR|POLLPRI;;
7186         poll_wait(filp, &md_event_waiters, wait);
7187 
7188         /* always allow read */
7189         mask = POLLIN | POLLRDNORM;
7190 
7191         if (seq->poll_event != atomic_read(&md_event_count))
7192                 mask |= POLLERR | POLLPRI;
7193         return mask;
7194 }
7195 
7196 static const struct file_operations md_seq_fops = {
7197         .owner          = THIS_MODULE,
7198         .open           = md_seq_open,
7199         .read           = seq_read,
7200         .llseek         = seq_lseek,
7201         .release        = seq_release_private,
7202         .poll           = mdstat_poll,
7203 };
7204 
7205 int register_md_personality(struct md_personality *p)
7206 {
7207         spin_lock(&pers_lock);
7208         list_add_tail(&p->list, &pers_list);
7209         printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
7210         spin_unlock(&pers_lock);
7211         return 0;
7212 }
7213 
7214 int unregister_md_personality(struct md_personality *p)
7215 {
7216         printk(KERN_INFO "md: %s personality unregistered\n", p->name);
7217         spin_lock(&pers_lock);
7218         list_del_init(&p->list);
7219         spin_unlock(&pers_lock);
7220         return 0;
7221 }
7222 
7223 static int is_mddev_idle(struct mddev *mddev, int init)
7224 {
7225         struct md_rdev * rdev;
7226         int idle;
7227         int curr_events;
7228 
7229         idle = 1;
7230         rcu_read_lock();
7231         rdev_for_each_rcu(rdev, mddev) {
7232                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
7233                 curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
7234                               (int)part_stat_read(&disk->part0, sectors[1]) -
7235                               atomic_read(&disk->sync_io);
7236                 /* sync IO will cause sync_io to increase before the disk_stats
7237                  * as sync_io is counted when a request starts, and
7238                  * disk_stats is counted when it completes.
7239                  * So resync activity will cause curr_events to be smaller than
7240                  * when there was no such activity.
7241                  * non-sync IO will cause disk_stat to increase without
7242                  * increasing sync_io so curr_events will (eventually)
7243                  * be larger than it was before.  Once it becomes
7244                  * substantially larger, the test below will cause
7245                  * the array to appear non-idle, and resync will slow
7246                  * down.
7247                  * If there is a lot of outstanding resync activity when
7248                  * we set last_event to curr_events, then all that activity
7249                  * completing might cause the array to appear non-idle
7250                  * and resync will be slowed down even though there might
7251                  * not have been non-resync activity.  This will only
7252                  * happen once though.  'last_events' will soon reflect
7253                  * the state where there is little or no outstanding
7254                  * resync requests, and further resync activity will
7255                  * always make curr_events less than last_events.
7256                  *
7257                  */
7258                 if (init || curr_events - rdev->last_events > 64) {
7259                         rdev->last_events = curr_events;
7260                         idle = 0;
7261                 }
7262         }
7263         rcu_read_unlock();
7264         return idle;
7265 }
7266 
7267 void md_done_sync(struct mddev *mddev, int blocks, int ok)
7268 {
7269         /* another "blocks" (512byte) blocks have been synced */
7270         atomic_sub(blocks, &mddev->recovery_active);
7271         wake_up(&mddev->recovery_wait);
7272         if (!ok) {
7273                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7274                 set_bit(MD_RECOVERY_ERROR, &mddev->recovery);
7275                 md_wakeup_thread(mddev->thread);
7276                 // stop recovery, signal do_sync ....
7277         }
7278 }
7279 
7280 
7281 /* md_write_start(mddev, bi)
7282  * If we need to update some array metadata (e.g. 'active' flag
7283  * in superblock) before writing, schedule a superblock update
7284  * and wait for it to complete.
7285  */
7286 void md_write_start(struct mddev *mddev, struct bio *bi)
7287 {
7288         int did_change = 0;
7289         if (bio_data_dir(bi) != WRITE)
7290                 return;
7291 
7292         BUG_ON(mddev->ro == 1);
7293         if (mddev->ro == 2) {
7294                 /* need to switch to read/write */
7295                 mddev->ro = 0;
7296                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7297                 md_wakeup_thread(mddev->thread);
7298                 md_wakeup_thread(mddev->sync_thread);
7299                 did_change = 1;
7300         }
7301         atomic_inc(&mddev->writes_pending);
7302         if (mddev->safemode == 1)
7303                 mddev->safemode = 0;
7304         if (mddev->in_sync) {
7305                 spin_lock_irq(&mddev->write_lock);
7306                 if (mddev->in_sync) {
7307                         mddev->in_sync = 0;
7308                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7309                         set_bit(MD_CHANGE_PENDING, &mddev->flags);
7310                         md_wakeup_thread(mddev->thread);
7311                         did_change = 1;
7312                 }
7313                 spin_unlock_irq(&mddev->write_lock);
7314         }
7315         if (did_change)
7316                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7317         wait_event(mddev->sb_wait,
7318                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
7319 }
7320 
7321 void md_write_end(struct mddev *mddev)
7322 {
7323         if (atomic_dec_and_test(&mddev->writes_pending)) {
7324                 if (mddev->safemode == 2)
7325                         md_wakeup_thread(mddev->thread);
7326                 else if (mddev->safemode_delay)
7327                         mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
7328         }
7329 }
7330 
7331 /* md_allow_write(mddev)
7332  * Calling this ensures that the array is marked 'active' so that writes
7333  * may proceed without blocking.  It is important to call this before
7334  * attempting a GFP_KERNEL allocation while holding the mddev lock.
7335  * Must be called with mddev_lock held.
7336  *
7337  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
7338  * is dropped, so return -EAGAIN after notifying userspace.
7339  */
7340 int md_allow_write(struct mddev *mddev)
7341 {
7342         if (!mddev->pers)
7343                 return 0;
7344         if (mddev->ro)
7345                 return 0;
7346         if (!mddev->pers->sync_request)
7347                 return 0;
7348 
7349         spin_lock_irq(&mddev->write_lock);
7350         if (mddev->in_sync) {
7351                 mddev->in_sync = 0;
7352                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7353                 set_bit(MD_CHANGE_PENDING, &mddev->flags);
7354                 if (mddev->safemode_delay &&
7355                     mddev->safemode == 0)
7356                         mddev->safemode = 1;
7357                 spin_unlock_irq(&mddev->write_lock);
7358                 md_update_sb(mddev, 0);
7359                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7360         } else
7361                 spin_unlock_irq(&mddev->write_lock);
7362 
7363         if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
7364                 return -EAGAIN;
7365         else
7366                 return 0;
7367 }
7368 EXPORT_SYMBOL_GPL(md_allow_write);
7369 
7370 #define SYNC_MARKS      10
7371 #define SYNC_MARK_STEP  (3*HZ)
7372 #define UPDATE_FREQUENCY (5*60*HZ)
7373 void md_do_sync(struct md_thread *thread)
7374 {
7375         struct mddev *mddev = thread->mddev;
7376         struct mddev *mddev2;
7377         unsigned int currspeed = 0,
7378                  window;
7379         sector_t max_sectors,j, io_sectors, recovery_done;
7380         unsigned long mark[SYNC_MARKS];
7381         unsigned long update_time;
7382         sector_t mark_cnt[SYNC_MARKS];
7383         int last_mark,m;
7384         struct list_head *tmp;
7385         sector_t last_check;
7386         int skipped = 0;
7387         struct md_rdev *rdev;
7388         char *desc, *action = NULL;
7389         struct blk_plug plug;
7390 
7391         /* just incase thread restarts... */
7392         if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7393                 return;
7394         if (mddev->ro) {/* never try to sync a read-only array */
7395                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7396                 return;
7397         }
7398 
7399         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7400                 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
7401                         desc = "data-check";
7402                         action = "check";
7403                 } else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7404                         desc = "requested-resync";
7405                         action = "repair";
7406                 } else
7407                         desc = "resync";
7408         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7409                 desc = "reshape";
7410         else
7411                 desc = "recovery";
7412 
7413         mddev->last_sync_action = action ?: desc;
7414 
7415         /* we overload curr_resync somewhat here.
7416          * 0 == not engaged in resync at all
7417          * 2 == checking that there is no conflict with another sync
7418          * 1 == like 2, but have yielded to allow conflicting resync to
7419          *              commense
7420          * other == active in resync - this many blocks
7421          *
7422          * Before starting a resync we must have set curr_resync to
7423          * 2, and then checked that every "conflicting" array has curr_resync
7424          * less than ours.  When we find one that is the same or higher
7425          * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
7426          * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
7427          * This will mean we have to start checking from the beginning again.
7428          *
7429          */
7430 
7431         do {
7432                 mddev->curr_resync = 2;
7433 
7434         try_again:
7435                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7436                         goto skip;
7437                 for_each_mddev(mddev2, tmp) {
7438                         if (mddev2 == mddev)
7439                                 continue;
7440                         if (!mddev->parallel_resync
7441                         &&  mddev2->curr_resync
7442                         &&  match_mddev_units(mddev, mddev2)) {
7443                                 DEFINE_WAIT(wq);
7444                                 if (mddev < mddev2 && mddev->curr_resync == 2) {
7445                                         /* arbitrarily yield */
7446                                         mddev->curr_resync = 1;
7447                                         wake_up(&resync_wait);
7448                                 }
7449                                 if (mddev > mddev2 && mddev->curr_resync == 1)
7450                                         /* no need to wait here, we can wait the next
7451                                          * time 'round when curr_resync == 2
7452                                          */
7453                                         continue;
7454                                 /* We need to wait 'interruptible' so as not to
7455                                  * contribute to the load average, and not to
7456                                  * be caught by 'softlockup'
7457                                  */
7458                                 prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7459                                 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7460                                     mddev2->curr_resync >= mddev->curr_resync) {
7461                                         printk(KERN_INFO "md: delaying %s of %s"
7462                                                " until %s has finished (they"
7463                                                " share one or more physical units)\n",
7464                                                desc, mdname(mddev), mdname(mddev2));
7465                                         mddev_put(mddev2);
7466                                         if (signal_pending(current))
7467                                                 flush_signals(current);
7468                                         schedule();
7469                                         finish_wait(&resync_wait, &wq);
7470                                         goto try_again;
7471                                 }
7472                                 finish_wait(&resync_wait, &wq);
7473                         }
7474                 }
7475         } while (mddev->curr_resync < 2);
7476 
7477         j = 0;
7478         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7479                 /* resync follows the size requested by the personality,
7480                  * which defaults to physical size, but can be virtual size
7481                  */
7482                 max_sectors = mddev->resync_max_sectors;
7483                 atomic64_set(&mddev->resync_mismatches, 0);
7484                 /* we don't use the checkpoint if there's a bitmap */
7485                 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7486                         j = mddev->resync_min;
7487                 else if (!mddev->bitmap)
7488                         j = mddev->recovery_cp;
7489 
7490         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7491                 max_sectors = mddev->resync_max_sectors;
7492         else {
7493                 /* recovery follows the physical size of devices */
7494                 max_sectors = mddev->dev_sectors;
7495                 j = MaxSector;
7496                 rcu_read_lock();
7497                 rdev_for_each_rcu(rdev, mddev)
7498                         if (rdev->raid_disk >= 0 &&
7499                             !test_bit(Faulty, &rdev->flags) &&
7500                             !test_bit(In_sync, &rdev->flags) &&
7501                             rdev->recovery_offset < j)
7502                                 j = rdev->recovery_offset;
7503                 rcu_read_unlock();
7504 
7505                 /* If there is a bitmap, we need to make sure all
7506                  * writes that started before we added a spare
7507                  * complete before we start doing a recovery.
7508                  * Otherwise the write might complete and (via
7509                  * bitmap_endwrite) set a bit in the bitmap after the
7510                  * recovery has checked that bit and skipped that
7511                  * region.
7512                  */
7513                 if (mddev->bitmap) {
7514                         mddev->pers->quiesce(mddev, 1);
7515                         mddev->pers->quiesce(mddev, 0);
7516                 }
7517         }
7518 
7519         printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7520         printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7521                 " %d KB/sec/disk.\n", speed_min(mddev));
7522         printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7523                "(but not more than %d KB/sec) for %s.\n",
7524                speed_max(mddev), desc);
7525 
7526         is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7527 
7528         io_sectors = 0;
7529         for (m = 0; m < SYNC_MARKS; m++) {
7530                 mark[m] = jiffies;
7531                 mark_cnt[m] = io_sectors;
7532         }
7533         last_mark = 0;
7534         mddev->resync_mark = mark[last_mark];
7535         mddev->resync_mark_cnt = mark_cnt[last_mark];
7536 
7537         /*
7538          * Tune reconstruction:
7539          */
7540         window = 32*(PAGE_SIZE/512);
7541         printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7542                 window/2, (unsigned long long)max_sectors/2);
7543 
7544         atomic_set(&mddev->recovery_active, 0);
7545         last_check = 0;
7546 
7547         if (j>2) {
7548                 printk(KERN_INFO
7549                        "md: resuming %s of %s from checkpoint.\n",
7550                        desc, mdname(mddev));
7551                 mddev->curr_resync = j;
7552         } else
7553                 mddev->curr_resync = 3; /* no longer delayed */
7554         mddev->curr_resync_completed = j;
7555         sysfs_notify(&mddev->kobj, NUL