c6e44a836a53a5f10702d5e42ad0ba1a87622831
[firefly-linux-kernel-4.4.55.git] / 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 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
76
77 /*
78  * Default number of read corrections we'll attempt on an rdev
79  * before ejecting it from the array. We divide the read error
80  * count by 2 for every hour elapsed between read errors.
81  */
82 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
83 /*
84  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
85  * is 1000 KB/sec, so the extra system load does not show up that much.
86  * Increase it if you want to have more _guaranteed_ speed. Note that
87  * the RAID driver will use the maximum available bandwidth if the IO
88  * subsystem is idle. There is also an 'absolute maximum' reconstruction
89  * speed limit - in case reconstruction slows down your system despite
90  * idle IO detection.
91  *
92  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
93  * or /sys/block/mdX/md/sync_speed_{min,max}
94  */
95
96 static int sysctl_speed_limit_min = 1000;
97 static int sysctl_speed_limit_max = 200000;
98 static inline int speed_min(struct mddev *mddev)
99 {
100         return mddev->sync_speed_min ?
101                 mddev->sync_speed_min : sysctl_speed_limit_min;
102 }
103
104 static inline int speed_max(struct mddev *mddev)
105 {
106         return mddev->sync_speed_max ?
107                 mddev->sync_speed_max : sysctl_speed_limit_max;
108 }
109
110 static struct ctl_table_header *raid_table_header;
111
112 static ctl_table raid_table[] = {
113         {
114                 .procname       = "speed_limit_min",
115                 .data           = &sysctl_speed_limit_min,
116                 .maxlen         = sizeof(int),
117                 .mode           = S_IRUGO|S_IWUSR,
118                 .proc_handler   = proc_dointvec,
119         },
120         {
121                 .procname       = "speed_limit_max",
122                 .data           = &sysctl_speed_limit_max,
123                 .maxlen         = sizeof(int),
124                 .mode           = S_IRUGO|S_IWUSR,
125                 .proc_handler   = proc_dointvec,
126         },
127         { }
128 };
129
130 static ctl_table raid_dir_table[] = {
131         {
132                 .procname       = "raid",
133                 .maxlen         = 0,
134                 .mode           = S_IRUGO|S_IXUGO,
135                 .child          = raid_table,
136         },
137         { }
138 };
139
140 static ctl_table raid_root_table[] = {
141         {
142                 .procname       = "dev",
143                 .maxlen         = 0,
144                 .mode           = 0555,
145                 .child          = raid_dir_table,
146         },
147         {  }
148 };
149
150 static const struct block_device_operations md_fops;
151
152 static int start_readonly;
153
154 /* bio_clone_mddev
155  * like bio_clone, but with a local bio set
156  */
157
158 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
159                             struct mddev *mddev)
160 {
161         struct bio *b;
162
163         if (!mddev || !mddev->bio_set)
164                 return bio_alloc(gfp_mask, nr_iovecs);
165
166         b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
167         if (!b)
168                 return NULL;
169         return b;
170 }
171 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
172
173 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
174                             struct mddev *mddev)
175 {
176         if (!mddev || !mddev->bio_set)
177                 return bio_clone(bio, gfp_mask);
178
179         return bio_clone_bioset(bio, gfp_mask, mddev->bio_set);
180 }
181 EXPORT_SYMBOL_GPL(bio_clone_mddev);
182
183 void md_trim_bio(struct bio *bio, int offset, int size)
184 {
185         /* 'bio' is a cloned bio which we need to trim to match
186          * the given offset and size.
187          * This requires adjusting bi_sector, bi_size, and bi_io_vec
188          */
189         int i;
190         struct bio_vec *bvec;
191         int sofar = 0;
192
193         size <<= 9;
194         if (offset == 0 && size == bio->bi_size)
195                 return;
196
197         bio->bi_sector += offset;
198         bio->bi_size = size;
199         offset <<= 9;
200         clear_bit(BIO_SEG_VALID, &bio->bi_flags);
201
202         while (bio->bi_idx < bio->bi_vcnt &&
203                bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
204                 /* remove this whole bio_vec */
205                 offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
206                 bio->bi_idx++;
207         }
208         if (bio->bi_idx < bio->bi_vcnt) {
209                 bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
210                 bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
211         }
212         /* avoid any complications with bi_idx being non-zero*/
213         if (bio->bi_idx) {
214                 memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
215                         (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
216                 bio->bi_vcnt -= bio->bi_idx;
217                 bio->bi_idx = 0;
218         }
219         /* Make sure vcnt and last bv are not too big */
220         bio_for_each_segment(bvec, bio, i) {
221                 if (sofar + bvec->bv_len > size)
222                         bvec->bv_len = size - sofar;
223                 if (bvec->bv_len == 0) {
224                         bio->bi_vcnt = i;
225                         break;
226                 }
227                 sofar += bvec->bv_len;
228         }
229 }
230 EXPORT_SYMBOL_GPL(md_trim_bio);
231
232 /*
233  * We have a system wide 'event count' that is incremented
234  * on any 'interesting' event, and readers of /proc/mdstat
235  * can use 'poll' or 'select' to find out when the event
236  * count increases.
237  *
238  * Events are:
239  *  start array, stop array, error, add device, remove device,
240  *  start build, activate spare
241  */
242 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
243 static atomic_t md_event_count;
244 void md_new_event(struct mddev *mddev)
245 {
246         atomic_inc(&md_event_count);
247         wake_up(&md_event_waiters);
248 }
249 EXPORT_SYMBOL_GPL(md_new_event);
250
251 /* Alternate version that can be called from interrupts
252  * when calling sysfs_notify isn't needed.
253  */
254 static void md_new_event_inintr(struct mddev *mddev)
255 {
256         atomic_inc(&md_event_count);
257         wake_up(&md_event_waiters);
258 }
259
260 /*
261  * Enables to iterate over all existing md arrays
262  * all_mddevs_lock protects this list.
263  */
264 static LIST_HEAD(all_mddevs);
265 static DEFINE_SPINLOCK(all_mddevs_lock);
266
267
268 /*
269  * iterates through all used mddevs in the system.
270  * We take care to grab the all_mddevs_lock whenever navigating
271  * the list, and to always hold a refcount when unlocked.
272  * Any code which breaks out of this loop while own
273  * a reference to the current mddev and must mddev_put it.
274  */
275 #define for_each_mddev(_mddev,_tmp)                                     \
276                                                                         \
277         for (({ spin_lock(&all_mddevs_lock);                            \
278                 _tmp = all_mddevs.next;                                 \
279                 _mddev = NULL;});                                       \
280              ({ if (_tmp != &all_mddevs)                                \
281                         mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
282                 spin_unlock(&all_mddevs_lock);                          \
283                 if (_mddev) mddev_put(_mddev);                          \
284                 _mddev = list_entry(_tmp, struct mddev, all_mddevs);    \
285                 _tmp != &all_mddevs;});                                 \
286              ({ spin_lock(&all_mddevs_lock);                            \
287                 _tmp = _tmp->next;})                                    \
288                 )
289
290
291 /* Rather than calling directly into the personality make_request function,
292  * IO requests come here first so that we can check if the device is
293  * being suspended pending a reconfiguration.
294  * We hold a refcount over the call to ->make_request.  By the time that
295  * call has finished, the bio has been linked into some internal structure
296  * and so is visible to ->quiesce(), so we don't need the refcount any more.
297  */
298 static void md_make_request(struct request_queue *q, struct bio *bio)
299 {
300         const int rw = bio_data_dir(bio);
301         struct mddev *mddev = q->queuedata;
302         int cpu;
303         unsigned int sectors;
304
305         if (mddev == NULL || mddev->pers == NULL
306             || !mddev->ready) {
307                 bio_io_error(bio);
308                 return;
309         }
310         if (mddev->ro == 1 && unlikely(rw == WRITE)) {
311                 bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
312                 return;
313         }
314         smp_rmb(); /* Ensure implications of  'active' are visible */
315         rcu_read_lock();
316         if (mddev->suspended) {
317                 DEFINE_WAIT(__wait);
318                 for (;;) {
319                         prepare_to_wait(&mddev->sb_wait, &__wait,
320                                         TASK_UNINTERRUPTIBLE);
321                         if (!mddev->suspended)
322                                 break;
323                         rcu_read_unlock();
324                         schedule();
325                         rcu_read_lock();
326                 }
327                 finish_wait(&mddev->sb_wait, &__wait);
328         }
329         atomic_inc(&mddev->active_io);
330         rcu_read_unlock();
331
332         /*
333          * save the sectors now since our bio can
334          * go away inside make_request
335          */
336         sectors = bio_sectors(bio);
337         mddev->pers->make_request(mddev, bio);
338
339         cpu = part_stat_lock();
340         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
341         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
342         part_stat_unlock();
343
344         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
345                 wake_up(&mddev->sb_wait);
346 }
347
348 /* mddev_suspend makes sure no new requests are submitted
349  * to the device, and that any requests that have been submitted
350  * are completely handled.
351  * Once ->stop is called and completes, the module will be completely
352  * unused.
353  */
354 void mddev_suspend(struct mddev *mddev)
355 {
356         BUG_ON(mddev->suspended);
357         mddev->suspended = 1;
358         synchronize_rcu();
359         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
360         mddev->pers->quiesce(mddev, 1);
361
362         del_timer_sync(&mddev->safemode_timer);
363 }
364 EXPORT_SYMBOL_GPL(mddev_suspend);
365
366 void mddev_resume(struct mddev *mddev)
367 {
368         mddev->suspended = 0;
369         wake_up(&mddev->sb_wait);
370         mddev->pers->quiesce(mddev, 0);
371
372         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
373         md_wakeup_thread(mddev->thread);
374         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
375 }
376 EXPORT_SYMBOL_GPL(mddev_resume);
377
378 int mddev_congested(struct mddev *mddev, int bits)
379 {
380         return mddev->suspended;
381 }
382 EXPORT_SYMBOL(mddev_congested);
383
384 /*
385  * Generic flush handling for md
386  */
387
388 static void md_end_flush(struct bio *bio, int err)
389 {
390         struct md_rdev *rdev = bio->bi_private;
391         struct mddev *mddev = rdev->mddev;
392
393         rdev_dec_pending(rdev, mddev);
394
395         if (atomic_dec_and_test(&mddev->flush_pending)) {
396                 /* The pre-request flush has finished */
397                 queue_work(md_wq, &mddev->flush_work);
398         }
399         bio_put(bio);
400 }
401
402 static void md_submit_flush_data(struct work_struct *ws);
403
404 static void submit_flushes(struct work_struct *ws)
405 {
406         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
407         struct md_rdev *rdev;
408
409         INIT_WORK(&mddev->flush_work, md_submit_flush_data);
410         atomic_set(&mddev->flush_pending, 1);
411         rcu_read_lock();
412         rdev_for_each_rcu(rdev, mddev)
413                 if (rdev->raid_disk >= 0 &&
414                     !test_bit(Faulty, &rdev->flags)) {
415                         /* Take two references, one is dropped
416                          * when request finishes, one after
417                          * we reclaim rcu_read_lock
418                          */
419                         struct bio *bi;
420                         atomic_inc(&rdev->nr_pending);
421                         atomic_inc(&rdev->nr_pending);
422                         rcu_read_unlock();
423                         bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
424                         bi->bi_end_io = md_end_flush;
425                         bi->bi_private = rdev;
426                         bi->bi_bdev = rdev->bdev;
427                         atomic_inc(&mddev->flush_pending);
428                         submit_bio(WRITE_FLUSH, bi);
429                         rcu_read_lock();
430                         rdev_dec_pending(rdev, mddev);
431                 }
432         rcu_read_unlock();
433         if (atomic_dec_and_test(&mddev->flush_pending))
434                 queue_work(md_wq, &mddev->flush_work);
435 }
436
437 static void md_submit_flush_data(struct work_struct *ws)
438 {
439         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
440         struct bio *bio = mddev->flush_bio;
441
442         if (bio->bi_size == 0)
443                 /* an empty barrier - all done */
444                 bio_endio(bio, 0);
445         else {
446                 bio->bi_rw &= ~REQ_FLUSH;
447                 mddev->pers->make_request(mddev, bio);
448         }
449
450         mddev->flush_bio = NULL;
451         wake_up(&mddev->sb_wait);
452 }
453
454 void md_flush_request(struct mddev *mddev, struct bio *bio)
455 {
456         spin_lock_irq(&mddev->write_lock);
457         wait_event_lock_irq(mddev->sb_wait,
458                             !mddev->flush_bio,
459                             mddev->write_lock);
460         mddev->flush_bio = bio;
461         spin_unlock_irq(&mddev->write_lock);
462
463         INIT_WORK(&mddev->flush_work, submit_flushes);
464         queue_work(md_wq, &mddev->flush_work);
465 }
466 EXPORT_SYMBOL(md_flush_request);
467
468 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
469 {
470         struct mddev *mddev = cb->data;
471         md_wakeup_thread(mddev->thread);
472         kfree(cb);
473 }
474 EXPORT_SYMBOL(md_unplug);
475
476 static inline struct mddev *mddev_get(struct mddev *mddev)
477 {
478         atomic_inc(&mddev->active);
479         return mddev;
480 }
481
482 static void mddev_delayed_delete(struct work_struct *ws);
483
484 static void mddev_put(struct mddev *mddev)
485 {
486         struct bio_set *bs = NULL;
487
488         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
489                 return;
490         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
491             mddev->ctime == 0 && !mddev->hold_active) {
492                 /* Array is not configured at all, and not held active,
493                  * so destroy it */
494                 list_del_init(&mddev->all_mddevs);
495                 bs = mddev->bio_set;
496                 mddev->bio_set = NULL;
497                 if (mddev->gendisk) {
498                         /* We did a probe so need to clean up.  Call
499                          * queue_work inside the spinlock so that
500                          * flush_workqueue() after mddev_find will
501                          * succeed in waiting for the work to be done.
502                          */
503                         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
504                         queue_work(md_misc_wq, &mddev->del_work);
505                 } else
506                         kfree(mddev);
507         }
508         spin_unlock(&all_mddevs_lock);
509         if (bs)
510                 bioset_free(bs);
511 }
512
513 void mddev_init(struct mddev *mddev)
514 {
515         mutex_init(&mddev->open_mutex);
516         mutex_init(&mddev->reconfig_mutex);
517         mutex_init(&mddev->bitmap_info.mutex);
518         INIT_LIST_HEAD(&mddev->disks);
519         INIT_LIST_HEAD(&mddev->all_mddevs);
520         init_timer(&mddev->safemode_timer);
521         atomic_set(&mddev->active, 1);
522         atomic_set(&mddev->openers, 0);
523         atomic_set(&mddev->active_io, 0);
524         spin_lock_init(&mddev->write_lock);
525         atomic_set(&mddev->flush_pending, 0);
526         init_waitqueue_head(&mddev->sb_wait);
527         init_waitqueue_head(&mddev->recovery_wait);
528         mddev->reshape_position = MaxSector;
529         mddev->reshape_backwards = 0;
530         mddev->resync_min = 0;
531         mddev->resync_max = MaxSector;
532         mddev->level = LEVEL_NONE;
533 }
534 EXPORT_SYMBOL_GPL(mddev_init);
535
536 static struct mddev * mddev_find(dev_t unit)
537 {
538         struct mddev *mddev, *new = NULL;
539
540         if (unit && MAJOR(unit) != MD_MAJOR)
541                 unit &= ~((1<<MdpMinorShift)-1);
542
543  retry:
544         spin_lock(&all_mddevs_lock);
545
546         if (unit) {
547                 list_for_each_entry(mddev, &all_mddevs, all_mddevs)
548                         if (mddev->unit == unit) {
549                                 mddev_get(mddev);
550                                 spin_unlock(&all_mddevs_lock);
551                                 kfree(new);
552                                 return mddev;
553                         }
554
555                 if (new) {
556                         list_add(&new->all_mddevs, &all_mddevs);
557                         spin_unlock(&all_mddevs_lock);
558                         new->hold_active = UNTIL_IOCTL;
559                         return new;
560                 }
561         } else if (new) {
562                 /* find an unused unit number */
563                 static int next_minor = 512;
564                 int start = next_minor;
565                 int is_free = 0;
566                 int dev = 0;
567                 while (!is_free) {
568                         dev = MKDEV(MD_MAJOR, next_minor);
569                         next_minor++;
570                         if (next_minor > MINORMASK)
571                                 next_minor = 0;
572                         if (next_minor == start) {
573                                 /* Oh dear, all in use. */
574                                 spin_unlock(&all_mddevs_lock);
575                                 kfree(new);
576                                 return NULL;
577                         }
578                                 
579                         is_free = 1;
580                         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
581                                 if (mddev->unit == dev) {
582                                         is_free = 0;
583                                         break;
584                                 }
585                 }
586                 new->unit = dev;
587                 new->md_minor = MINOR(dev);
588                 new->hold_active = UNTIL_STOP;
589                 list_add(&new->all_mddevs, &all_mddevs);
590                 spin_unlock(&all_mddevs_lock);
591                 return new;
592         }
593         spin_unlock(&all_mddevs_lock);
594
595         new = kzalloc(sizeof(*new), GFP_KERNEL);
596         if (!new)
597                 return NULL;
598
599         new->unit = unit;
600         if (MAJOR(unit) == MD_MAJOR)
601                 new->md_minor = MINOR(unit);
602         else
603                 new->md_minor = MINOR(unit) >> MdpMinorShift;
604
605         mddev_init(new);
606
607         goto retry;
608 }
609
610 static inline int mddev_lock(struct mddev * mddev)
611 {
612         return mutex_lock_interruptible(&mddev->reconfig_mutex);
613 }
614
615 static inline int mddev_is_locked(struct mddev *mddev)
616 {
617         return mutex_is_locked(&mddev->reconfig_mutex);
618 }
619
620 static inline int mddev_trylock(struct mddev * mddev)
621 {
622         return mutex_trylock(&mddev->reconfig_mutex);
623 }
624
625 static struct attribute_group md_redundancy_group;
626
627 static void mddev_unlock(struct mddev * mddev)
628 {
629         if (mddev->to_remove) {
630                 /* These cannot be removed under reconfig_mutex as
631                  * an access to the files will try to take reconfig_mutex
632                  * while holding the file unremovable, which leads to
633                  * a deadlock.
634                  * So hold set sysfs_active while the remove in happeing,
635                  * and anything else which might set ->to_remove or my
636                  * otherwise change the sysfs namespace will fail with
637                  * -EBUSY if sysfs_active is still set.
638                  * We set sysfs_active under reconfig_mutex and elsewhere
639                  * test it under the same mutex to ensure its correct value
640                  * is seen.
641                  */
642                 struct attribute_group *to_remove = mddev->to_remove;
643                 mddev->to_remove = NULL;
644                 mddev->sysfs_active = 1;
645                 mutex_unlock(&mddev->reconfig_mutex);
646
647                 if (mddev->kobj.sd) {
648                         if (to_remove != &md_redundancy_group)
649                                 sysfs_remove_group(&mddev->kobj, to_remove);
650                         if (mddev->pers == NULL ||
651                             mddev->pers->sync_request == NULL) {
652                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
653                                 if (mddev->sysfs_action)
654                                         sysfs_put(mddev->sysfs_action);
655                                 mddev->sysfs_action = NULL;
656                         }
657                 }
658                 mddev->sysfs_active = 0;
659         } else
660                 mutex_unlock(&mddev->reconfig_mutex);
661
662         /* As we've dropped the mutex we need a spinlock to
663          * make sure the thread doesn't disappear
664          */
665         spin_lock(&pers_lock);
666         md_wakeup_thread(mddev->thread);
667         spin_unlock(&pers_lock);
668 }
669
670 static struct md_rdev * find_rdev_nr(struct mddev *mddev, int nr)
671 {
672         struct md_rdev *rdev;
673
674         rdev_for_each(rdev, mddev)
675                 if (rdev->desc_nr == nr)
676                         return rdev;
677
678         return NULL;
679 }
680
681 static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
682 {
683         struct md_rdev *rdev;
684
685         rdev_for_each_rcu(rdev, mddev)
686                 if (rdev->desc_nr == nr)
687                         return rdev;
688
689         return NULL;
690 }
691
692 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
693 {
694         struct md_rdev *rdev;
695
696         rdev_for_each(rdev, mddev)
697                 if (rdev->bdev->bd_dev == dev)
698                         return rdev;
699
700         return NULL;
701 }
702
703 static struct md_rdev *find_rdev_rcu(struct mddev *mddev, dev_t dev)
704 {
705         struct md_rdev *rdev;
706
707         rdev_for_each_rcu(rdev, mddev)
708                 if (rdev->bdev->bd_dev == dev)
709                         return rdev;
710
711         return NULL;
712 }
713
714 static struct md_personality *find_pers(int level, char *clevel)
715 {
716         struct md_personality *pers;
717         list_for_each_entry(pers, &pers_list, list) {
718                 if (level != LEVEL_NONE && pers->level == level)
719                         return pers;
720                 if (strcmp(pers->name, clevel)==0)
721                         return pers;
722         }
723         return NULL;
724 }
725
726 /* return the offset of the super block in 512byte sectors */
727 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
728 {
729         sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
730         return MD_NEW_SIZE_SECTORS(num_sectors);
731 }
732
733 static int alloc_disk_sb(struct md_rdev * rdev)
734 {
735         if (rdev->sb_page)
736                 MD_BUG();
737
738         rdev->sb_page = alloc_page(GFP_KERNEL);
739         if (!rdev->sb_page) {
740                 printk(KERN_ALERT "md: out of memory.\n");
741                 return -ENOMEM;
742         }
743
744         return 0;
745 }
746
747 void md_rdev_clear(struct md_rdev *rdev)
748 {
749         if (rdev->sb_page) {
750                 put_page(rdev->sb_page);
751                 rdev->sb_loaded = 0;
752                 rdev->sb_page = NULL;
753                 rdev->sb_start = 0;
754                 rdev->sectors = 0;
755         }
756         if (rdev->bb_page) {
757                 put_page(rdev->bb_page);
758                 rdev->bb_page = NULL;
759         }
760         kfree(rdev->badblocks.page);
761         rdev->badblocks.page = NULL;
762 }
763 EXPORT_SYMBOL_GPL(md_rdev_clear);
764
765 static void super_written(struct bio *bio, int error)
766 {
767         struct md_rdev *rdev = bio->bi_private;
768         struct mddev *mddev = rdev->mddev;
769
770         if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
771                 printk("md: super_written gets error=%d, uptodate=%d\n",
772                        error, test_bit(BIO_UPTODATE, &bio->bi_flags));
773                 WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
774                 md_error(mddev, rdev);
775         }
776
777         if (atomic_dec_and_test(&mddev->pending_writes))
778                 wake_up(&mddev->sb_wait);
779         bio_put(bio);
780 }
781
782 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
783                    sector_t sector, int size, struct page *page)
784 {
785         /* write first size bytes of page to sector of rdev
786          * Increment mddev->pending_writes before returning
787          * and decrement it on completion, waking up sb_wait
788          * if zero is reached.
789          * If an error occurred, call md_error
790          */
791         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
792
793         bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
794         bio->bi_sector = sector;
795         bio_add_page(bio, page, size, 0);
796         bio->bi_private = rdev;
797         bio->bi_end_io = super_written;
798
799         atomic_inc(&mddev->pending_writes);
800         submit_bio(WRITE_FLUSH_FUA, bio);
801 }
802
803 void md_super_wait(struct mddev *mddev)
804 {
805         /* wait for all superblock writes that were scheduled to complete */
806         DEFINE_WAIT(wq);
807         for(;;) {
808                 prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
809                 if (atomic_read(&mddev->pending_writes)==0)
810                         break;
811                 schedule();
812         }
813         finish_wait(&mddev->sb_wait, &wq);
814 }
815
816 static void bi_complete(struct bio *bio, int error)
817 {
818         complete((struct completion*)bio->bi_private);
819 }
820
821 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
822                  struct page *page, int rw, bool metadata_op)
823 {
824         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
825         struct completion event;
826         int ret;
827
828         rw |= REQ_SYNC;
829
830         bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
831                 rdev->meta_bdev : rdev->bdev;
832         if (metadata_op)
833                 bio->bi_sector = sector + rdev->sb_start;
834         else if (rdev->mddev->reshape_position != MaxSector &&
835                  (rdev->mddev->reshape_backwards ==
836                   (sector >= rdev->mddev->reshape_position)))
837                 bio->bi_sector = sector + rdev->new_data_offset;
838         else
839                 bio->bi_sector = sector + rdev->data_offset;
840         bio_add_page(bio, page, size, 0);
841         init_completion(&event);
842         bio->bi_private = &event;
843         bio->bi_end_io = bi_complete;
844         submit_bio(rw, bio);
845         wait_for_completion(&event);
846
847         ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
848         bio_put(bio);
849         return ret;
850 }
851 EXPORT_SYMBOL_GPL(sync_page_io);
852
853 static int read_disk_sb(struct md_rdev * rdev, int size)
854 {
855         char b[BDEVNAME_SIZE];
856         if (!rdev->sb_page) {
857                 MD_BUG();
858                 return -EINVAL;
859         }
860         if (rdev->sb_loaded)
861                 return 0;
862
863
864         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
865                 goto fail;
866         rdev->sb_loaded = 1;
867         return 0;
868
869 fail:
870         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
871                 bdevname(rdev->bdev,b));
872         return -EINVAL;
873 }
874
875 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
876 {
877         return  sb1->set_uuid0 == sb2->set_uuid0 &&
878                 sb1->set_uuid1 == sb2->set_uuid1 &&
879                 sb1->set_uuid2 == sb2->set_uuid2 &&
880                 sb1->set_uuid3 == sb2->set_uuid3;
881 }
882
883 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
884 {
885         int ret;
886         mdp_super_t *tmp1, *tmp2;
887
888         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
889         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
890
891         if (!tmp1 || !tmp2) {
892                 ret = 0;
893                 printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
894                 goto abort;
895         }
896
897         *tmp1 = *sb1;
898         *tmp2 = *sb2;
899
900         /*
901          * nr_disks is not constant
902          */
903         tmp1->nr_disks = 0;
904         tmp2->nr_disks = 0;
905
906         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
907 abort:
908         kfree(tmp1);
909         kfree(tmp2);
910         return ret;
911 }
912
913
914 static u32 md_csum_fold(u32 csum)
915 {
916         csum = (csum & 0xffff) + (csum >> 16);
917         return (csum & 0xffff) + (csum >> 16);
918 }
919
920 static unsigned int calc_sb_csum(mdp_super_t * sb)
921 {
922         u64 newcsum = 0;
923         u32 *sb32 = (u32*)sb;
924         int i;
925         unsigned int disk_csum, csum;
926
927         disk_csum = sb->sb_csum;
928         sb->sb_csum = 0;
929
930         for (i = 0; i < MD_SB_BYTES/4 ; i++)
931                 newcsum += sb32[i];
932         csum = (newcsum & 0xffffffff) + (newcsum>>32);
933
934
935 #ifdef CONFIG_ALPHA
936         /* This used to use csum_partial, which was wrong for several
937          * reasons including that different results are returned on
938          * different architectures.  It isn't critical that we get exactly
939          * the same return value as before (we always csum_fold before
940          * testing, and that removes any differences).  However as we
941          * know that csum_partial always returned a 16bit value on
942          * alphas, do a fold to maximise conformity to previous behaviour.
943          */
944         sb->sb_csum = md_csum_fold(disk_csum);
945 #else
946         sb->sb_csum = disk_csum;
947 #endif
948         return csum;
949 }
950
951
952 /*
953  * Handle superblock details.
954  * We want to be able to handle multiple superblock formats
955  * so we have a common interface to them all, and an array of
956  * different handlers.
957  * We rely on user-space to write the initial superblock, and support
958  * reading and updating of superblocks.
959  * Interface methods are:
960  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
961  *      loads and validates a superblock on dev.
962  *      if refdev != NULL, compare superblocks on both devices
963  *    Return:
964  *      0 - dev has a superblock that is compatible with refdev
965  *      1 - dev has a superblock that is compatible and newer than refdev
966  *          so dev should be used as the refdev in future
967  *     -EINVAL superblock incompatible or invalid
968  *     -othererror e.g. -EIO
969  *
970  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
971  *      Verify that dev is acceptable into mddev.
972  *       The first time, mddev->raid_disks will be 0, and data from
973  *       dev should be merged in.  Subsequent calls check that dev
974  *       is new enough.  Return 0 or -EINVAL
975  *
976  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
977  *     Update the superblock for rdev with data in mddev
978  *     This does not write to disc.
979  *
980  */
981
982 struct super_type  {
983         char                *name;
984         struct module       *owner;
985         int                 (*load_super)(struct md_rdev *rdev,
986                                           struct md_rdev *refdev,
987                                           int minor_version);
988         int                 (*validate_super)(struct mddev *mddev,
989                                               struct md_rdev *rdev);
990         void                (*sync_super)(struct mddev *mddev,
991                                           struct md_rdev *rdev);
992         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
993                                                 sector_t num_sectors);
994         int                 (*allow_new_offset)(struct md_rdev *rdev,
995                                                 unsigned long long new_offset);
996 };
997
998 /*
999  * Check that the given mddev has no bitmap.
1000  *
1001  * This function is called from the run method of all personalities that do not
1002  * support bitmaps. It prints an error message and returns non-zero if mddev
1003  * has a bitmap. Otherwise, it returns 0.
1004  *
1005  */
1006 int md_check_no_bitmap(struct mddev *mddev)
1007 {
1008         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
1009                 return 0;
1010         printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
1011                 mdname(mddev), mddev->pers->name);
1012         return 1;
1013 }
1014 EXPORT_SYMBOL(md_check_no_bitmap);
1015
1016 /*
1017  * load_super for 0.90.0 
1018  */
1019 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1020 {
1021         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1022         mdp_super_t *sb;
1023         int ret;
1024
1025         /*
1026          * Calculate the position of the superblock (512byte sectors),
1027          * it's at the end of the disk.
1028          *
1029          * It also happens to be a multiple of 4Kb.
1030          */
1031         rdev->sb_start = calc_dev_sboffset(rdev);
1032
1033         ret = read_disk_sb(rdev, MD_SB_BYTES);
1034         if (ret) return ret;
1035
1036         ret = -EINVAL;
1037
1038         bdevname(rdev->bdev, b);
1039         sb = page_address(rdev->sb_page);
1040
1041         if (sb->md_magic != MD_SB_MAGIC) {
1042                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
1043                        b);
1044                 goto abort;
1045         }
1046
1047         if (sb->major_version != 0 ||
1048             sb->minor_version < 90 ||
1049             sb->minor_version > 91) {
1050                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1051                         sb->major_version, sb->minor_version,
1052                         b);
1053                 goto abort;
1054         }
1055
1056         if (sb->raid_disks <= 0)
1057                 goto abort;
1058
1059         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1060                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1061                         b);
1062                 goto abort;
1063         }
1064
1065         rdev->preferred_minor = sb->md_minor;
1066         rdev->data_offset = 0;
1067         rdev->new_data_offset = 0;
1068         rdev->sb_size = MD_SB_BYTES;
1069         rdev->badblocks.shift = -1;
1070
1071         if (sb->level == LEVEL_MULTIPATH)
1072                 rdev->desc_nr = -1;
1073         else
1074                 rdev->desc_nr = sb->this_disk.number;
1075
1076         if (!refdev) {
1077                 ret = 1;
1078         } else {
1079                 __u64 ev1, ev2;
1080                 mdp_super_t *refsb = page_address(refdev->sb_page);
1081                 if (!uuid_equal(refsb, sb)) {
1082                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
1083                                 b, bdevname(refdev->bdev,b2));
1084                         goto abort;
1085                 }
1086                 if (!sb_equal(refsb, sb)) {
1087                         printk(KERN_WARNING "md: %s has same UUID"
1088                                " but different superblock to %s\n",
1089                                b, bdevname(refdev->bdev, b2));
1090                         goto abort;
1091                 }
1092                 ev1 = md_event(sb);
1093                 ev2 = md_event(refsb);
1094                 if (ev1 > ev2)
1095                         ret = 1;
1096                 else 
1097                         ret = 0;
1098         }
1099         rdev->sectors = rdev->sb_start;
1100         /* Limit to 4TB as metadata cannot record more than that.
1101          * (not needed for Linear and RAID0 as metadata doesn't
1102          * record this size)
1103          */
1104         if (rdev->sectors >= (2ULL << 32) && sb->level >= 1)
1105                 rdev->sectors = (2ULL << 32) - 2;
1106
1107         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1108                 /* "this cannot possibly happen" ... */
1109                 ret = -EINVAL;
1110
1111  abort:
1112         return ret;
1113 }
1114
1115 /*
1116  * validate_super for 0.90.0
1117  */
1118 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1119 {
1120         mdp_disk_t *desc;
1121         mdp_super_t *sb = page_address(rdev->sb_page);
1122         __u64 ev1 = md_event(sb);
1123
1124         rdev->raid_disk = -1;
1125         clear_bit(Faulty, &rdev->flags);
1126         clear_bit(In_sync, &rdev->flags);
1127         clear_bit(WriteMostly, &rdev->flags);
1128
1129         if (mddev->raid_disks == 0) {
1130                 mddev->major_version = 0;
1131                 mddev->minor_version = sb->minor_version;
1132                 mddev->patch_version = sb->patch_version;
1133                 mddev->external = 0;
1134                 mddev->chunk_sectors = sb->chunk_size >> 9;
1135                 mddev->ctime = sb->ctime;
1136                 mddev->utime = sb->utime;
1137                 mddev->level = sb->level;
1138                 mddev->clevel[0] = 0;
1139                 mddev->layout = sb->layout;
1140                 mddev->raid_disks = sb->raid_disks;
1141                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1142                 mddev->events = ev1;
1143                 mddev->bitmap_info.offset = 0;
1144                 mddev->bitmap_info.space = 0;
1145                 /* bitmap can use 60 K after the 4K superblocks */
1146                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1147                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1148                 mddev->reshape_backwards = 0;
1149
1150                 if (mddev->minor_version >= 91) {
1151                         mddev->reshape_position = sb->reshape_position;
1152                         mddev->delta_disks = sb->delta_disks;
1153                         mddev->new_level = sb->new_level;
1154                         mddev->new_layout = sb->new_layout;
1155                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1156                         if (mddev->delta_disks < 0)
1157                                 mddev->reshape_backwards = 1;
1158                 } else {
1159                         mddev->reshape_position = MaxSector;
1160                         mddev->delta_disks = 0;
1161                         mddev->new_level = mddev->level;
1162                         mddev->new_layout = mddev->layout;
1163                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1164                 }
1165
1166                 if (sb->state & (1<<MD_SB_CLEAN))
1167                         mddev->recovery_cp = MaxSector;
1168                 else {
1169                         if (sb->events_hi == sb->cp_events_hi && 
1170                                 sb->events_lo == sb->cp_events_lo) {
1171                                 mddev->recovery_cp = sb->recovery_cp;
1172                         } else
1173                                 mddev->recovery_cp = 0;
1174                 }
1175
1176                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1177                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1178                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1179                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1180
1181                 mddev->max_disks = MD_SB_DISKS;
1182
1183                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1184                     mddev->bitmap_info.file == NULL) {
1185                         mddev->bitmap_info.offset =
1186                                 mddev->bitmap_info.default_offset;
1187                         mddev->bitmap_info.space =
1188                                 mddev->bitmap_info.space;
1189                 }
1190
1191         } else if (mddev->pers == NULL) {
1192                 /* Insist on good event counter while assembling, except
1193                  * for spares (which don't need an event count) */
1194                 ++ev1;
1195                 if (sb->disks[rdev->desc_nr].state & (
1196                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1197                         if (ev1 < mddev->events) 
1198                                 return -EINVAL;
1199         } else if (mddev->bitmap) {
1200                 /* if adding to array with a bitmap, then we can accept an
1201                  * older device ... but not too old.
1202                  */
1203                 if (ev1 < mddev->bitmap->events_cleared)
1204                         return 0;
1205         } else {
1206                 if (ev1 < mddev->events)
1207                         /* just a hot-add of a new device, leave raid_disk at -1 */
1208                         return 0;
1209         }
1210
1211         if (mddev->level != LEVEL_MULTIPATH) {
1212                 desc = sb->disks + rdev->desc_nr;
1213
1214                 if (desc->state & (1<<MD_DISK_FAULTY))
1215                         set_bit(Faulty, &rdev->flags);
1216                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1217                             desc->raid_disk < mddev->raid_disks */) {
1218                         set_bit(In_sync, &rdev->flags);
1219                         rdev->raid_disk = desc->raid_disk;
1220                 } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1221                         /* active but not in sync implies recovery up to
1222                          * reshape position.  We don't know exactly where
1223                          * that is, so set to zero for now */
1224                         if (mddev->minor_version >= 91) {
1225                                 rdev->recovery_offset = 0;
1226                                 rdev->raid_disk = desc->raid_disk;
1227                         }
1228                 }
1229                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1230                         set_bit(WriteMostly, &rdev->flags);
1231         } else /* MULTIPATH are always insync */
1232                 set_bit(In_sync, &rdev->flags);
1233         return 0;
1234 }
1235
1236 /*
1237  * sync_super for 0.90.0
1238  */
1239 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1240 {
1241         mdp_super_t *sb;
1242         struct md_rdev *rdev2;
1243         int next_spare = mddev->raid_disks;
1244
1245
1246         /* make rdev->sb match mddev data..
1247          *
1248          * 1/ zero out disks
1249          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1250          * 3/ any empty disks < next_spare become removed
1251          *
1252          * disks[0] gets initialised to REMOVED because
1253          * we cannot be sure from other fields if it has
1254          * been initialised or not.
1255          */
1256         int i;
1257         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1258
1259         rdev->sb_size = MD_SB_BYTES;
1260
1261         sb = page_address(rdev->sb_page);
1262
1263         memset(sb, 0, sizeof(*sb));
1264
1265         sb->md_magic = MD_SB_MAGIC;
1266         sb->major_version = mddev->major_version;
1267         sb->patch_version = mddev->patch_version;
1268         sb->gvalid_words  = 0; /* ignored */
1269         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1270         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1271         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1272         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1273
1274         sb->ctime = mddev->ctime;
1275         sb->level = mddev->level;
1276         sb->size = mddev->dev_sectors / 2;
1277         sb->raid_disks = mddev->raid_disks;
1278         sb->md_minor = mddev->md_minor;
1279         sb->not_persistent = 0;
1280         sb->utime = mddev->utime;
1281         sb->state = 0;
1282         sb->events_hi = (mddev->events>>32);
1283         sb->events_lo = (u32)mddev->events;
1284
1285         if (mddev->reshape_position == MaxSector)
1286                 sb->minor_version = 90;
1287         else {
1288                 sb->minor_version = 91;
1289                 sb->reshape_position = mddev->reshape_position;
1290                 sb->new_level = mddev->new_level;
1291                 sb->delta_disks = mddev->delta_disks;
1292                 sb->new_layout = mddev->new_layout;
1293                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1294         }
1295         mddev->minor_version = sb->minor_version;
1296         if (mddev->in_sync)
1297         {
1298                 sb->recovery_cp = mddev->recovery_cp;
1299                 sb->cp_events_hi = (mddev->events>>32);
1300                 sb->cp_events_lo = (u32)mddev->events;
1301                 if (mddev->recovery_cp == MaxSector)
1302                         sb->state = (1<< MD_SB_CLEAN);
1303         } else
1304                 sb->recovery_cp = 0;
1305
1306         sb->layout = mddev->layout;
1307         sb->chunk_size = mddev->chunk_sectors << 9;
1308
1309         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1310                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1311
1312         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1313         rdev_for_each(rdev2, mddev) {
1314                 mdp_disk_t *d;
1315                 int desc_nr;
1316                 int is_active = test_bit(In_sync, &rdev2->flags);
1317
1318                 if (rdev2->raid_disk >= 0 &&
1319                     sb->minor_version >= 91)
1320                         /* we have nowhere to store the recovery_offset,
1321                          * but if it is not below the reshape_position,
1322                          * we can piggy-back on that.
1323                          */
1324                         is_active = 1;
1325                 if (rdev2->raid_disk < 0 ||
1326                     test_bit(Faulty, &rdev2->flags))
1327                         is_active = 0;
1328                 if (is_active)
1329                         desc_nr = rdev2->raid_disk;
1330                 else
1331                         desc_nr = next_spare++;
1332                 rdev2->desc_nr = desc_nr;
1333                 d = &sb->disks[rdev2->desc_nr];
1334                 nr_disks++;
1335                 d->number = rdev2->desc_nr;
1336                 d->major = MAJOR(rdev2->bdev->bd_dev);
1337                 d->minor = MINOR(rdev2->bdev->bd_dev);
1338                 if (is_active)
1339                         d->raid_disk = rdev2->raid_disk;
1340                 else
1341                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1342                 if (test_bit(Faulty, &rdev2->flags))
1343                         d->state = (1<<MD_DISK_FAULTY);
1344                 else if (is_active) {
1345                         d->state = (1<<MD_DISK_ACTIVE);
1346                         if (test_bit(In_sync, &rdev2->flags))
1347                                 d->state |= (1<<MD_DISK_SYNC);
1348                         active++;
1349                         working++;
1350                 } else {
1351                         d->state = 0;
1352                         spare++;
1353                         working++;
1354                 }
1355                 if (test_bit(WriteMostly, &rdev2->flags))
1356                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1357         }
1358         /* now set the "removed" and "faulty" bits on any missing devices */
1359         for (i=0 ; i < mddev->raid_disks ; i++) {
1360                 mdp_disk_t *d = &sb->disks[i];
1361                 if (d->state == 0 && d->number == 0) {
1362                         d->number = i;
1363                         d->raid_disk = i;
1364                         d->state = (1<<MD_DISK_REMOVED);
1365                         d->state |= (1<<MD_DISK_FAULTY);
1366                         failed++;
1367                 }
1368         }
1369         sb->nr_disks = nr_disks;
1370         sb->active_disks = active;
1371         sb->working_disks = working;
1372         sb->failed_disks = failed;
1373         sb->spare_disks = spare;
1374
1375         sb->this_disk = sb->disks[rdev->desc_nr];
1376         sb->sb_csum = calc_sb_csum(sb);
1377 }
1378
1379 /*
1380  * rdev_size_change for 0.90.0
1381  */
1382 static unsigned long long
1383 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1384 {
1385         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1386                 return 0; /* component must fit device */
1387         if (rdev->mddev->bitmap_info.offset)
1388                 return 0; /* can't move bitmap */
1389         rdev->sb_start = calc_dev_sboffset(rdev);
1390         if (!num_sectors || num_sectors > rdev->sb_start)
1391                 num_sectors = rdev->sb_start;
1392         /* Limit to 4TB as metadata cannot record more than that.
1393          * 4TB == 2^32 KB, or 2*2^32 sectors.
1394          */
1395         if (num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
1396                 num_sectors = (2ULL << 32) - 2;
1397         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1398                        rdev->sb_page);
1399         md_super_wait(rdev->mddev);
1400         return num_sectors;
1401 }
1402
1403 static int
1404 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1405 {
1406         /* non-zero offset changes not possible with v0.90 */
1407         return new_offset == 0;
1408 }
1409
1410 /*
1411  * version 1 superblock
1412  */
1413
1414 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1415 {
1416         __le32 disk_csum;
1417         u32 csum;
1418         unsigned long long newcsum;
1419         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1420         __le32 *isuper = (__le32*)sb;
1421
1422         disk_csum = sb->sb_csum;
1423         sb->sb_csum = 0;
1424         newcsum = 0;
1425         for (; size >= 4; size -= 4)
1426                 newcsum += le32_to_cpu(*isuper++);
1427
1428         if (size == 2)
1429                 newcsum += le16_to_cpu(*(__le16*) isuper);
1430
1431         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1432         sb->sb_csum = disk_csum;
1433         return cpu_to_le32(csum);
1434 }
1435
1436 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1437                             int acknowledged);
1438 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1439 {
1440         struct mdp_superblock_1 *sb;
1441         int ret;
1442         sector_t sb_start;
1443         sector_t sectors;
1444         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1445         int bmask;
1446
1447         /*
1448          * Calculate the position of the superblock in 512byte sectors.
1449          * It is always aligned to a 4K boundary and
1450          * depeding on minor_version, it can be:
1451          * 0: At least 8K, but less than 12K, from end of device
1452          * 1: At start of device
1453          * 2: 4K from start of device.
1454          */
1455         switch(minor_version) {
1456         case 0:
1457                 sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1458                 sb_start -= 8*2;
1459                 sb_start &= ~(sector_t)(4*2-1);
1460                 break;
1461         case 1:
1462                 sb_start = 0;
1463                 break;
1464         case 2:
1465                 sb_start = 8;
1466                 break;
1467         default:
1468                 return -EINVAL;
1469         }
1470         rdev->sb_start = sb_start;
1471
1472         /* superblock is rarely larger than 1K, but it can be larger,
1473          * and it is safe to read 4k, so we do that
1474          */
1475         ret = read_disk_sb(rdev, 4096);
1476         if (ret) return ret;
1477
1478
1479         sb = page_address(rdev->sb_page);
1480
1481         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1482             sb->major_version != cpu_to_le32(1) ||
1483             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1484             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1485             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1486                 return -EINVAL;
1487
1488         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1489                 printk("md: invalid superblock checksum on %s\n",
1490                         bdevname(rdev->bdev,b));
1491                 return -EINVAL;
1492         }
1493         if (le64_to_cpu(sb->data_size) < 10) {
1494                 printk("md: data_size too small on %s\n",
1495                        bdevname(rdev->bdev,b));
1496                 return -EINVAL;
1497         }
1498         if (sb->pad0 ||
1499             sb->pad3[0] ||
1500             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1501                 /* Some padding is non-zero, might be a new feature */
1502                 return -EINVAL;
1503
1504         rdev->preferred_minor = 0xffff;
1505         rdev->data_offset = le64_to_cpu(sb->data_offset);
1506         rdev->new_data_offset = rdev->data_offset;
1507         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1508             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1509                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1510         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1511
1512         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1513         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1514         if (rdev->sb_size & bmask)
1515                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1516
1517         if (minor_version
1518             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1519                 return -EINVAL;
1520         if (minor_version
1521             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1522                 return -EINVAL;
1523
1524         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1525                 rdev->desc_nr = -1;
1526         else
1527                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1528
1529         if (!rdev->bb_page) {
1530                 rdev->bb_page = alloc_page(GFP_KERNEL);
1531                 if (!rdev->bb_page)
1532                         return -ENOMEM;
1533         }
1534         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1535             rdev->badblocks.count == 0) {
1536                 /* need to load the bad block list.
1537                  * Currently we limit it to one page.
1538                  */
1539                 s32 offset;
1540                 sector_t bb_sector;
1541                 u64 *bbp;
1542                 int i;
1543                 int sectors = le16_to_cpu(sb->bblog_size);
1544                 if (sectors > (PAGE_SIZE / 512))
1545                         return -EINVAL;
1546                 offset = le32_to_cpu(sb->bblog_offset);
1547                 if (offset == 0)
1548                         return -EINVAL;
1549                 bb_sector = (long long)offset;
1550                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1551                                   rdev->bb_page, READ, true))
1552                         return -EIO;
1553                 bbp = (u64 *)page_address(rdev->bb_page);
1554                 rdev->badblocks.shift = sb->bblog_shift;
1555                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1556                         u64 bb = le64_to_cpu(*bbp);
1557                         int count = bb & (0x3ff);
1558                         u64 sector = bb >> 10;
1559                         sector <<= sb->bblog_shift;
1560                         count <<= sb->bblog_shift;
1561                         if (bb + 1 == 0)
1562                                 break;
1563                         if (md_set_badblocks(&rdev->badblocks,
1564                                              sector, count, 1) == 0)
1565                                 return -EINVAL;
1566                 }
1567         } else if (sb->bblog_offset == 0)
1568                 rdev->badblocks.shift = -1;
1569
1570         if (!refdev) {
1571                 ret = 1;
1572         } else {
1573                 __u64 ev1, ev2;
1574                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1575
1576                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1577                     sb->level != refsb->level ||
1578                     sb->layout != refsb->layout ||
1579                     sb->chunksize != refsb->chunksize) {
1580                         printk(KERN_WARNING "md: %s has strangely different"
1581                                 " superblock to %s\n",
1582                                 bdevname(rdev->bdev,b),
1583                                 bdevname(refdev->bdev,b2));
1584                         return -EINVAL;
1585                 }
1586                 ev1 = le64_to_cpu(sb->events);
1587                 ev2 = le64_to_cpu(refsb->events);
1588
1589                 if (ev1 > ev2)
1590                         ret = 1;
1591                 else
1592                         ret = 0;
1593         }
1594         if (minor_version) {
1595                 sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1596                 sectors -= rdev->data_offset;
1597         } else
1598                 sectors = rdev->sb_start;
1599         if (sectors < le64_to_cpu(sb->data_size))
1600                 return -EINVAL;
1601         rdev->sectors = le64_to_cpu(sb->data_size);
1602         return ret;
1603 }
1604
1605 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1606 {
1607         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1608         __u64 ev1 = le64_to_cpu(sb->events);
1609
1610         rdev->raid_disk = -1;
1611         clear_bit(Faulty, &rdev->flags);
1612         clear_bit(In_sync, &rdev->flags);
1613         clear_bit(WriteMostly, &rdev->flags);
1614
1615         if (mddev->raid_disks == 0) {
1616                 mddev->major_version = 1;
1617                 mddev->patch_version = 0;
1618                 mddev->external = 0;
1619                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1620                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1621                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1622                 mddev->level = le32_to_cpu(sb->level);
1623                 mddev->clevel[0] = 0;
1624                 mddev->layout = le32_to_cpu(sb->layout);
1625                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1626                 mddev->dev_sectors = le64_to_cpu(sb->size);
1627                 mddev->events = ev1;
1628                 mddev->bitmap_info.offset = 0;
1629                 mddev->bitmap_info.space = 0;
1630                 /* Default location for bitmap is 1K after superblock
1631                  * using 3K - total of 4K
1632                  */
1633                 mddev->bitmap_info.default_offset = 1024 >> 9;
1634                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1635                 mddev->reshape_backwards = 0;
1636
1637                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1638                 memcpy(mddev->uuid, sb->set_uuid, 16);
1639
1640                 mddev->max_disks =  (4096-256)/2;
1641
1642                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1643                     mddev->bitmap_info.file == NULL) {
1644                         mddev->bitmap_info.offset =
1645                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1646                         /* Metadata doesn't record how much space is available.
1647                          * For 1.0, we assume we can use up to the superblock
1648                          * if before, else to 4K beyond superblock.
1649                          * For others, assume no change is possible.
1650                          */
1651                         if (mddev->minor_version > 0)
1652                                 mddev->bitmap_info.space = 0;
1653                         else if (mddev->bitmap_info.offset > 0)
1654                                 mddev->bitmap_info.space =
1655                                         8 - mddev->bitmap_info.offset;
1656                         else
1657                                 mddev->bitmap_info.space =
1658                                         -mddev->bitmap_info.offset;
1659                 }
1660
1661                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1662                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1663                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1664                         mddev->new_level = le32_to_cpu(sb->new_level);
1665                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1666                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1667                         if (mddev->delta_disks < 0 ||
1668                             (mddev->delta_disks == 0 &&
1669                              (le32_to_cpu(sb->feature_map)
1670                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1671                                 mddev->reshape_backwards = 1;
1672                 } else {
1673                         mddev->reshape_position = MaxSector;
1674                         mddev->delta_disks = 0;
1675                         mddev->new_level = mddev->level;
1676                         mddev->new_layout = mddev->layout;
1677                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1678                 }
1679
1680         } else if (mddev->pers == NULL) {
1681                 /* Insist of good event counter while assembling, except for
1682                  * spares (which don't need an event count) */
1683                 ++ev1;
1684                 if (rdev->desc_nr >= 0 &&
1685                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1686                     le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1687                         if (ev1 < mddev->events)
1688                                 return -EINVAL;
1689         } else if (mddev->bitmap) {
1690                 /* If adding to array with a bitmap, then we can accept an
1691                  * older device, but not too old.
1692                  */
1693                 if (ev1 < mddev->bitmap->events_cleared)
1694                         return 0;
1695         } else {
1696                 if (ev1 < mddev->events)
1697                         /* just a hot-add of a new device, leave raid_disk at -1 */
1698                         return 0;
1699         }
1700         if (mddev->level != LEVEL_MULTIPATH) {
1701                 int role;
1702                 if (rdev->desc_nr < 0 ||
1703                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1704                         role = 0xffff;
1705                         rdev->desc_nr = -1;
1706                 } else
1707                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1708                 switch(role) {
1709                 case 0xffff: /* spare */
1710                         break;
1711                 case 0xfffe: /* faulty */
1712                         set_bit(Faulty, &rdev->flags);
1713                         break;
1714                 default:
1715                         if ((le32_to_cpu(sb->feature_map) &
1716                              MD_FEATURE_RECOVERY_OFFSET))
1717                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1718                         else
1719                                 set_bit(In_sync, &rdev->flags);
1720                         rdev->raid_disk = role;
1721                         break;
1722                 }
1723                 if (sb->devflags & WriteMostly1)
1724                         set_bit(WriteMostly, &rdev->flags);
1725                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1726                         set_bit(Replacement, &rdev->flags);
1727         } else /* MULTIPATH are always insync */
1728                 set_bit(In_sync, &rdev->flags);
1729
1730         return 0;
1731 }
1732
1733 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1734 {
1735         struct mdp_superblock_1 *sb;
1736         struct md_rdev *rdev2;
1737         int max_dev, i;
1738         /* make rdev->sb match mddev and rdev data. */
1739
1740         sb = page_address(rdev->sb_page);
1741
1742         sb->feature_map = 0;
1743         sb->pad0 = 0;
1744         sb->recovery_offset = cpu_to_le64(0);
1745         memset(sb->pad3, 0, sizeof(sb->pad3));
1746
1747         sb->utime = cpu_to_le64((__u64)mddev->utime);
1748         sb->events = cpu_to_le64(mddev->events);
1749         if (mddev->in_sync)
1750                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1751         else
1752                 sb->resync_offset = cpu_to_le64(0);
1753
1754         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1755
1756         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1757         sb->size = cpu_to_le64(mddev->dev_sectors);
1758         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1759         sb->level = cpu_to_le32(mddev->level);
1760         sb->layout = cpu_to_le32(mddev->layout);
1761
1762         if (test_bit(WriteMostly, &rdev->flags))
1763                 sb->devflags |= WriteMostly1;
1764         else
1765                 sb->devflags &= ~WriteMostly1;
1766         sb->data_offset = cpu_to_le64(rdev->data_offset);
1767         sb->data_size = cpu_to_le64(rdev->sectors);
1768
1769         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1770                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1771                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1772         }
1773
1774         if (rdev->raid_disk >= 0 &&
1775             !test_bit(In_sync, &rdev->flags)) {
1776                 sb->feature_map |=
1777                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1778                 sb->recovery_offset =
1779                         cpu_to_le64(rdev->recovery_offset);
1780         }
1781         if (test_bit(Replacement, &rdev->flags))
1782                 sb->feature_map |=
1783                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
1784
1785         if (mddev->reshape_position != MaxSector) {
1786                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1787                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1788                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1789                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1790                 sb->new_level = cpu_to_le32(mddev->new_level);
1791                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1792                 if (mddev->delta_disks == 0 &&
1793                     mddev->reshape_backwards)
1794                         sb->feature_map
1795                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1796                 if (rdev->new_data_offset != rdev->data_offset) {
1797                         sb->feature_map
1798                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1799                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1800                                                              - rdev->data_offset));
1801                 }
1802         }
1803
1804         if (rdev->badblocks.count == 0)
1805                 /* Nothing to do for bad blocks*/ ;
1806         else if (sb->bblog_offset == 0)
1807                 /* Cannot record bad blocks on this device */
1808                 md_error(mddev, rdev);
1809         else {
1810                 struct badblocks *bb = &rdev->badblocks;
1811                 u64 *bbp = (u64 *)page_address(rdev->bb_page);
1812                 u64 *p = bb->page;
1813                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1814                 if (bb->changed) {
1815                         unsigned seq;
1816
1817 retry:
1818                         seq = read_seqbegin(&bb->lock);
1819
1820                         memset(bbp, 0xff, PAGE_SIZE);
1821
1822                         for (i = 0 ; i < bb->count ; i++) {
1823                                 u64 internal_bb = p[i];
1824                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1825                                                 | BB_LEN(internal_bb));
1826                                 bbp[i] = cpu_to_le64(store_bb);
1827                         }
1828                         bb->changed = 0;
1829                         if (read_seqretry(&bb->lock, seq))
1830                                 goto retry;
1831
1832                         bb->sector = (rdev->sb_start +
1833                                       (int)le32_to_cpu(sb->bblog_offset));
1834                         bb->size = le16_to_cpu(sb->bblog_size);
1835                 }
1836         }
1837
1838         max_dev = 0;
1839         rdev_for_each(rdev2, mddev)
1840                 if (rdev2->desc_nr+1 > max_dev)
1841                         max_dev = rdev2->desc_nr+1;
1842
1843         if (max_dev > le32_to_cpu(sb->max_dev)) {
1844                 int bmask;
1845                 sb->max_dev = cpu_to_le32(max_dev);
1846                 rdev->sb_size = max_dev * 2 + 256;
1847                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1848                 if (rdev->sb_size & bmask)
1849                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
1850         } else
1851                 max_dev = le32_to_cpu(sb->max_dev);
1852
1853         for (i=0; i<max_dev;i++)
1854                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
1855         
1856         rdev_for_each(rdev2, mddev) {
1857                 i = rdev2->desc_nr;
1858                 if (test_bit(Faulty, &rdev2->flags))
1859                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
1860                 else if (test_bit(In_sync, &rdev2->flags))
1861                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1862                 else if (rdev2->raid_disk >= 0)
1863                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1864                 else
1865                         sb->dev_roles[i] = cpu_to_le16(0xffff);
1866         }
1867
1868         sb->sb_csum = calc_sb_1_csum(sb);
1869 }
1870
1871 static unsigned long long
1872 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1873 {
1874         struct mdp_superblock_1 *sb;
1875         sector_t max_sectors;
1876         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1877                 return 0; /* component must fit device */
1878         if (rdev->data_offset != rdev->new_data_offset)
1879                 return 0; /* too confusing */
1880         if (rdev->sb_start < rdev->data_offset) {
1881                 /* minor versions 1 and 2; superblock before data */
1882                 max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1883                 max_sectors -= rdev->data_offset;
1884                 if (!num_sectors || num_sectors > max_sectors)
1885                         num_sectors = max_sectors;
1886         } else if (rdev->mddev->bitmap_info.offset) {
1887                 /* minor version 0 with bitmap we can't move */
1888                 return 0;
1889         } else {
1890                 /* minor version 0; superblock after data */
1891                 sector_t sb_start;
1892                 sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1893                 sb_start &= ~(sector_t)(4*2 - 1);
1894                 max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1895                 if (!num_sectors || num_sectors > max_sectors)
1896                         num_sectors = max_sectors;
1897                 rdev->sb_start = sb_start;
1898         }
1899         sb = page_address(rdev->sb_page);
1900         sb->data_size = cpu_to_le64(num_sectors);
1901         sb->super_offset = rdev->sb_start;
1902         sb->sb_csum = calc_sb_1_csum(sb);
1903         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1904                        rdev->sb_page);
1905         md_super_wait(rdev->mddev);
1906         return num_sectors;
1907
1908 }
1909
1910 static int
1911 super_1_allow_new_offset(struct md_rdev *rdev,
1912                          unsigned long long new_offset)
1913 {
1914         /* All necessary checks on new >= old have been done */
1915         struct bitmap *bitmap;
1916         if (new_offset >= rdev->data_offset)
1917                 return 1;
1918
1919         /* with 1.0 metadata, there is no metadata to tread on
1920          * so we can always move back */
1921         if (rdev->mddev->minor_version == 0)
1922                 return 1;
1923
1924         /* otherwise we must be sure not to step on
1925          * any metadata, so stay:
1926          * 36K beyond start of superblock
1927          * beyond end of badblocks
1928          * beyond write-intent bitmap
1929          */
1930         if (rdev->sb_start + (32+4)*2 > new_offset)
1931                 return 0;
1932         bitmap = rdev->mddev->bitmap;
1933         if (bitmap && !rdev->mddev->bitmap_info.file &&
1934             rdev->sb_start + rdev->mddev->bitmap_info.offset +
1935             bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1936                 return 0;
1937         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1938                 return 0;
1939
1940         return 1;
1941 }
1942
1943 static struct super_type super_types[] = {
1944         [0] = {
1945                 .name   = "0.90.0",
1946                 .owner  = THIS_MODULE,
1947                 .load_super         = super_90_load,
1948                 .validate_super     = super_90_validate,
1949                 .sync_super         = super_90_sync,
1950                 .rdev_size_change   = super_90_rdev_size_change,
1951                 .allow_new_offset   = super_90_allow_new_offset,
1952         },
1953         [1] = {
1954                 .name   = "md-1",
1955                 .owner  = THIS_MODULE,
1956                 .load_super         = super_1_load,
1957                 .validate_super     = super_1_validate,
1958                 .sync_super         = super_1_sync,
1959                 .rdev_size_change   = super_1_rdev_size_change,
1960                 .allow_new_offset   = super_1_allow_new_offset,
1961         },
1962 };
1963
1964 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1965 {
1966         if (mddev->sync_super) {
1967                 mddev->sync_super(mddev, rdev);
1968                 return;
1969         }
1970
1971         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1972
1973         super_types[mddev->major_version].sync_super(mddev, rdev);
1974 }
1975
1976 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1977 {
1978         struct md_rdev *rdev, *rdev2;
1979
1980         rcu_read_lock();
1981         rdev_for_each_rcu(rdev, mddev1)
1982                 rdev_for_each_rcu(rdev2, mddev2)
1983                         if (rdev->bdev->bd_contains ==
1984                             rdev2->bdev->bd_contains) {
1985                                 rcu_read_unlock();
1986                                 return 1;
1987                         }
1988         rcu_read_unlock();
1989         return 0;
1990 }
1991
1992 static LIST_HEAD(pending_raid_disks);
1993
1994 /*
1995  * Try to register data integrity profile for an mddev
1996  *
1997  * This is called when an array is started and after a disk has been kicked
1998  * from the array. It only succeeds if all working and active component devices
1999  * are integrity capable with matching profiles.
2000  */
2001 int md_integrity_register(struct mddev *mddev)
2002 {
2003         struct md_rdev *rdev, *reference = NULL;
2004
2005         if (list_empty(&mddev->disks))
2006                 return 0; /* nothing to do */
2007         if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
2008                 return 0; /* shouldn't register, or already is */
2009         rdev_for_each(rdev, mddev) {
2010                 /* skip spares and non-functional disks */
2011                 if (test_bit(Faulty, &rdev->flags))
2012                         continue;
2013                 if (rdev->raid_disk < 0)
2014                         continue;
2015                 if (!reference) {
2016                         /* Use the first rdev as the reference */
2017                         reference = rdev;
2018                         continue;
2019                 }
2020                 /* does this rdev's profile match the reference profile? */
2021                 if (blk_integrity_compare(reference->bdev->bd_disk,
2022                                 rdev->bdev->bd_disk) < 0)
2023                         return -EINVAL;
2024         }
2025         if (!reference || !bdev_get_integrity(reference->bdev))
2026                 return 0;
2027         /*
2028          * All component devices are integrity capable and have matching
2029          * profiles, register the common profile for the md device.
2030          */
2031         if (blk_integrity_register(mddev->gendisk,
2032                         bdev_get_integrity(reference->bdev)) != 0) {
2033                 printk(KERN_ERR "md: failed to register integrity for %s\n",
2034                         mdname(mddev));
2035                 return -EINVAL;
2036         }
2037         printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2038         if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2039                 printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2040                        mdname(mddev));
2041                 return -EINVAL;
2042         }
2043         return 0;
2044 }
2045 EXPORT_SYMBOL(md_integrity_register);
2046
2047 /* Disable data integrity if non-capable/non-matching disk is being added */
2048 void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2049 {
2050         struct blk_integrity *bi_rdev;
2051         struct blk_integrity *bi_mddev;
2052
2053         if (!mddev->gendisk)
2054                 return;
2055
2056         bi_rdev = bdev_get_integrity(rdev->bdev);
2057         bi_mddev = blk_get_integrity(mddev->gendisk);
2058
2059         if (!bi_mddev) /* nothing to do */
2060                 return;
2061         if (rdev->raid_disk < 0) /* skip spares */
2062                 return;
2063         if (bi_rdev && blk_integrity_compare(mddev->gendisk,
2064                                              rdev->bdev->bd_disk) >= 0)
2065                 return;
2066         printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
2067         blk_integrity_unregister(mddev->gendisk);
2068 }
2069 EXPORT_SYMBOL(md_integrity_add_rdev);
2070
2071 static int bind_rdev_to_array(struct md_rdev * rdev, struct mddev * mddev)
2072 {
2073         char b[BDEVNAME_SIZE];
2074         struct kobject *ko;
2075         char *s;
2076         int err;
2077
2078         if (rdev->mddev) {
2079                 MD_BUG();
2080                 return -EINVAL;
2081         }
2082
2083         /* prevent duplicates */
2084         if (find_rdev(mddev, rdev->bdev->bd_dev))
2085                 return -EEXIST;
2086
2087         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2088         if (rdev->sectors && (mddev->dev_sectors == 0 ||
2089                         rdev->sectors < mddev->dev_sectors)) {
2090                 if (mddev->pers) {
2091                         /* Cannot change size, so fail
2092                          * If mddev->level <= 0, then we don't care
2093                          * about aligning sizes (e.g. linear)
2094                          */
2095                         if (mddev->level > 0)
2096                                 return -ENOSPC;
2097                 } else
2098                         mddev->dev_sectors = rdev->sectors;
2099         }
2100
2101         /* Verify rdev->desc_nr is unique.
2102          * If it is -1, assign a free number, else
2103          * check number is not in use
2104          */
2105         if (rdev->desc_nr < 0) {
2106                 int choice = 0;
2107                 if (mddev->pers) choice = mddev->raid_disks;
2108                 while (find_rdev_nr(mddev, choice))
2109                         choice++;
2110                 rdev->desc_nr = choice;
2111         } else {
2112                 if (find_rdev_nr(mddev, rdev->desc_nr))
2113                         return -EBUSY;
2114         }
2115         if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2116                 printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2117                        mdname(mddev), mddev->max_disks);
2118                 return -EBUSY;
2119         }
2120         bdevname(rdev->bdev,b);
2121         while ( (s=strchr(b, '/')) != NULL)
2122                 *s = '!';
2123
2124         rdev->mddev = mddev;
2125         printk(KERN_INFO "md: bind<%s>\n", b);
2126
2127         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2128                 goto fail;
2129
2130         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2131         if (sysfs_create_link(&rdev->kobj, ko, "block"))
2132                 /* failure here is OK */;
2133         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2134
2135         list_add_rcu(&rdev->same_set, &mddev->disks);
2136         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2137
2138         /* May as well allow recovery to be retried once */
2139         mddev->recovery_disabled++;
2140
2141         return 0;
2142
2143  fail:
2144         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2145                b, mdname(mddev));
2146         return err;
2147 }
2148
2149 static void md_delayed_delete(struct work_struct *ws)
2150 {
2151         struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2152         kobject_del(&rdev->kobj);
2153         kobject_put(&rdev->kobj);
2154 }
2155
2156 static void unbind_rdev_from_array(struct md_rdev * rdev)
2157 {
2158         char b[BDEVNAME_SIZE];
2159         if (!rdev->mddev) {
2160                 MD_BUG();
2161                 return;
2162         }
2163         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2164         list_del_rcu(&rdev->same_set);
2165         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2166         rdev->mddev = NULL;
2167         sysfs_remove_link(&rdev->kobj, "block");
2168         sysfs_put(rdev->sysfs_state);
2169         rdev->sysfs_state = NULL;
2170         rdev->badblocks.count = 0;
2171         /* We need to delay this, otherwise we can deadlock when
2172          * writing to 'remove' to "dev/state".  We also need
2173          * to delay it due to rcu usage.
2174          */
2175         synchronize_rcu();
2176         INIT_WORK(&rdev->del_work, md_delayed_delete);
2177         kobject_get(&rdev->kobj);
2178         queue_work(md_misc_wq, &rdev->del_work);
2179 }
2180
2181 /*
2182  * prevent the device from being mounted, repartitioned or
2183  * otherwise reused by a RAID array (or any other kernel
2184  * subsystem), by bd_claiming the device.
2185  */
2186 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2187 {
2188         int err = 0;
2189         struct block_device *bdev;
2190         char b[BDEVNAME_SIZE];
2191
2192         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2193                                  shared ? (struct md_rdev *)lock_rdev : rdev);
2194         if (IS_ERR(bdev)) {
2195                 printk(KERN_ERR "md: could not open %s.\n",
2196                         __bdevname(dev, b));
2197                 return PTR_ERR(bdev);
2198         }
2199         rdev->bdev = bdev;
2200         return err;
2201 }
2202
2203 static void unlock_rdev(struct md_rdev *rdev)
2204 {
2205         struct block_device *bdev = rdev->bdev;
2206         rdev->bdev = NULL;
2207         if (!bdev)
2208                 MD_BUG();
2209         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2210 }
2211
2212 void md_autodetect_dev(dev_t dev);
2213
2214 static void export_rdev(struct md_rdev * rdev)
2215 {
2216         char b[BDEVNAME_SIZE];
2217         printk(KERN_INFO "md: export_rdev(%s)\n",
2218                 bdevname(rdev->bdev,b));
2219         if (rdev->mddev)
2220                 MD_BUG();
2221         md_rdev_clear(rdev);
2222 #ifndef MODULE
2223         if (test_bit(AutoDetected, &rdev->flags))
2224                 md_autodetect_dev(rdev->bdev->bd_dev);
2225 #endif
2226         unlock_rdev(rdev);
2227         kobject_put(&rdev->kobj);
2228 }
2229
2230 static void kick_rdev_from_array(struct md_rdev * rdev)
2231 {
2232         unbind_rdev_from_array(rdev);
2233         export_rdev(rdev);
2234 }
2235
2236 static void export_array(struct mddev *mddev)
2237 {
2238         struct md_rdev *rdev, *tmp;
2239
2240         rdev_for_each_safe(rdev, tmp, mddev) {
2241                 if (!rdev->mddev) {
2242                         MD_BUG();
2243                         continue;
2244                 }
2245                 kick_rdev_from_array(rdev);
2246         }
2247         if (!list_empty(&mddev->disks))
2248                 MD_BUG();
2249         mddev->raid_disks = 0;
2250         mddev->major_version = 0;
2251 }
2252
2253 static void print_desc(mdp_disk_t *desc)
2254 {
2255         printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2256                 desc->major,desc->minor,desc->raid_disk,desc->state);
2257 }
2258
2259 static void print_sb_90(mdp_super_t *sb)
2260 {
2261         int i;
2262
2263         printk(KERN_INFO 
2264                 "md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2265                 sb->major_version, sb->minor_version, sb->patch_version,
2266                 sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2267                 sb->ctime);
2268         printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2269                 sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2270                 sb->md_minor, sb->layout, sb->chunk_size);
2271         printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2272                 " FD:%d SD:%d CSUM:%08x E:%08lx\n",
2273                 sb->utime, sb->state, sb->active_disks, sb->working_disks,
2274                 sb->failed_disks, sb->spare_disks,
2275                 sb->sb_csum, (unsigned long)sb->events_lo);
2276
2277         printk(KERN_INFO);
2278         for (i = 0; i < MD_SB_DISKS; i++) {
2279                 mdp_disk_t *desc;
2280
2281                 desc = sb->disks + i;
2282                 if (desc->number || desc->major || desc->minor ||
2283                     desc->raid_disk || (desc->state && (desc->state != 4))) {
2284                         printk("     D %2d: ", i);
2285                         print_desc(desc);
2286                 }
2287         }
2288         printk(KERN_INFO "md:     THIS: ");
2289         print_desc(&sb->this_disk);
2290 }
2291
2292 static void print_sb_1(struct mdp_superblock_1 *sb)
2293 {
2294         __u8 *uuid;
2295
2296         uuid = sb->set_uuid;
2297         printk(KERN_INFO
2298                "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2299                "md:    Name: \"%s\" CT:%llu\n",
2300                 le32_to_cpu(sb->major_version),
2301                 le32_to_cpu(sb->feature_map),
2302                 uuid,
2303                 sb->set_name,
2304                 (unsigned long long)le64_to_cpu(sb->ctime)
2305                        & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2306
2307         uuid = sb->device_uuid;
2308         printk(KERN_INFO
2309                "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2310                         " RO:%llu\n"
2311                "md:     Dev:%08x UUID: %pU\n"
2312                "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2313                "md:         (MaxDev:%u) \n",
2314                 le32_to_cpu(sb->level),
2315                 (unsigned long long)le64_to_cpu(sb->size),
2316                 le32_to_cpu(sb->raid_disks),
2317                 le32_to_cpu(sb->layout),
2318                 le32_to_cpu(sb->chunksize),
2319                 (unsigned long long)le64_to_cpu(sb->data_offset),
2320                 (unsigned long long)le64_to_cpu(sb->data_size),
2321                 (unsigned long long)le64_to_cpu(sb->super_offset),
2322                 (unsigned long long)le64_to_cpu(sb->recovery_offset),
2323                 le32_to_cpu(sb->dev_number),
2324                 uuid,
2325                 sb->devflags,
2326                 (unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2327                 (unsigned long long)le64_to_cpu(sb->events),
2328                 (unsigned long long)le64_to_cpu(sb->resync_offset),
2329                 le32_to_cpu(sb->sb_csum),
2330                 le32_to_cpu(sb->max_dev)
2331                 );
2332 }
2333
2334 static void print_rdev(struct md_rdev *rdev, int major_version)
2335 {
2336         char b[BDEVNAME_SIZE];
2337         printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2338                 bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2339                 test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2340                 rdev->desc_nr);
2341         if (rdev->sb_loaded) {
2342                 printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2343                 switch (major_version) {
2344                 case 0:
2345                         print_sb_90(page_address(rdev->sb_page));
2346                         break;
2347                 case 1:
2348                         print_sb_1(page_address(rdev->sb_page));
2349                         break;
2350                 }
2351         } else
2352                 printk(KERN_INFO "md: no rdev superblock!\n");
2353 }
2354
2355 static void md_print_devices(void)
2356 {
2357         struct list_head *tmp;
2358         struct md_rdev *rdev;
2359         struct mddev *mddev;
2360         char b[BDEVNAME_SIZE];
2361
2362         printk("\n");
2363         printk("md:     **********************************\n");
2364         printk("md:     * <COMPLETE RAID STATE PRINTOUT> *\n");
2365         printk("md:     **********************************\n");
2366         for_each_mddev(mddev, tmp) {
2367
2368                 if (mddev->bitmap)
2369                         bitmap_print_sb(mddev->bitmap);
2370                 else
2371                         printk("%s: ", mdname(mddev));
2372                 rdev_for_each(rdev, mddev)
2373                         printk("<%s>", bdevname(rdev->bdev,b));
2374                 printk("\n");
2375
2376                 rdev_for_each(rdev, mddev)
2377                         print_rdev(rdev, mddev->major_version);
2378         }
2379         printk("md:     **********************************\n");
2380         printk("\n");
2381 }
2382
2383
2384 static void sync_sbs(struct mddev * mddev, int nospares)
2385 {
2386         /* Update each superblock (in-memory image), but
2387          * if we are allowed to, skip spares which already
2388          * have the right event counter, or have one earlier
2389          * (which would mean they aren't being marked as dirty
2390          * with the rest of the array)
2391          */
2392         struct md_rdev *rdev;
2393         rdev_for_each(rdev, mddev) {
2394                 if (rdev->sb_events == mddev->events ||
2395                     (nospares &&
2396                      rdev->raid_disk < 0 &&
2397                      rdev->sb_events+1 == mddev->events)) {
2398                         /* Don't update this superblock */
2399                         rdev->sb_loaded = 2;
2400                 } else {
2401                         sync_super(mddev, rdev);
2402                         rdev->sb_loaded = 1;
2403                 }
2404         }
2405 }
2406
2407 static void md_update_sb(struct mddev * mddev, int force_change)
2408 {
2409         struct md_rdev *rdev;
2410         int sync_req;
2411         int nospares = 0;
2412         int any_badblocks_changed = 0;
2413
2414         if (mddev->ro) {
2415                 if (force_change)
2416                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2417                 return;
2418         }
2419 repeat:
2420         /* First make sure individual recovery_offsets are correct */
2421         rdev_for_each(rdev, mddev) {
2422                 if (rdev->raid_disk >= 0 &&
2423                     mddev->delta_disks >= 0 &&
2424                     !test_bit(In_sync, &rdev->flags) &&
2425                     mddev->curr_resync_completed > rdev->recovery_offset)
2426                                 rdev->recovery_offset = mddev->curr_resync_completed;
2427
2428         }       
2429         if (!mddev->persistent) {
2430                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2431                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2432                 if (!mddev->external) {
2433                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2434                         rdev_for_each(rdev, mddev) {
2435                                 if (rdev->badblocks.changed) {
2436                                         rdev->badblocks.changed = 0;
2437                                         md_ack_all_badblocks(&rdev->badblocks);
2438                                         md_error(mddev, rdev);
2439                                 }
2440                                 clear_bit(Blocked, &rdev->flags);
2441                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2442                                 wake_up(&rdev->blocked_wait);
2443                         }
2444                 }
2445                 wake_up(&mddev->sb_wait);
2446                 return;
2447         }
2448
2449         spin_lock_irq(&mddev->write_lock);
2450
2451         mddev->utime = get_seconds();
2452
2453         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2454                 force_change = 1;
2455         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2456                 /* just a clean<-> dirty transition, possibly leave spares alone,
2457                  * though if events isn't the right even/odd, we will have to do
2458                  * spares after all
2459                  */
2460                 nospares = 1;
2461         if (force_change)
2462                 nospares = 0;
2463         if (mddev->degraded)
2464                 /* If the array is degraded, then skipping spares is both
2465                  * dangerous and fairly pointless.
2466                  * Dangerous because a device that was removed from the array
2467                  * might have a event_count that still looks up-to-date,
2468                  * so it can be re-added without a resync.
2469                  * Pointless because if there are any spares to skip,
2470                  * then a recovery will happen and soon that array won't
2471                  * be degraded any more and the spare can go back to sleep then.
2472                  */
2473                 nospares = 0;
2474
2475         sync_req = mddev->in_sync;
2476
2477         /* If this is just a dirty<->clean transition, and the array is clean
2478          * and 'events' is odd, we can roll back to the previous clean state */
2479         if (nospares
2480             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2481             && mddev->can_decrease_events
2482             && mddev->events != 1) {
2483                 mddev->events--;
2484                 mddev->can_decrease_events = 0;
2485         } else {
2486                 /* otherwise we have to go forward and ... */
2487                 mddev->events ++;
2488                 mddev->can_decrease_events = nospares;
2489         }
2490
2491         if (!mddev->events) {
2492                 /*
2493                  * oops, this 64-bit counter should never wrap.
2494                  * Either we are in around ~1 trillion A.C., assuming
2495                  * 1 reboot per second, or we have a bug:
2496                  */
2497                 MD_BUG();
2498                 mddev->events --;
2499         }
2500
2501         rdev_for_each(rdev, mddev) {
2502                 if (rdev->badblocks.changed)
2503                         any_badblocks_changed++;
2504                 if (test_bit(Faulty, &rdev->flags))
2505                         set_bit(FaultRecorded, &rdev->flags);
2506         }
2507
2508         sync_sbs(mddev, nospares);
2509         spin_unlock_irq(&mddev->write_lock);
2510
2511         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2512                  mdname(mddev), mddev->in_sync);
2513
2514         bitmap_update_sb(mddev->bitmap);
2515         rdev_for_each(rdev, mddev) {
2516                 char b[BDEVNAME_SIZE];
2517
2518                 if (rdev->sb_loaded != 1)
2519                         continue; /* no noise on spare devices */
2520
2521                 if (!test_bit(Faulty, &rdev->flags) &&
2522                     rdev->saved_raid_disk == -1) {
2523                         md_super_write(mddev,rdev,
2524                                        rdev->sb_start, rdev->sb_size,
2525                                        rdev->sb_page);
2526                         pr_debug("md: (write) %s's sb offset: %llu\n",
2527                                  bdevname(rdev->bdev, b),
2528                                  (unsigned long long)rdev->sb_start);
2529                         rdev->sb_events = mddev->events;
2530                         if (rdev->badblocks.size) {
2531                                 md_super_write(mddev, rdev,
2532                                                rdev->badblocks.sector,
2533                                                rdev->badblocks.size << 9,
2534                                                rdev->bb_page);
2535                                 rdev->badblocks.size = 0;
2536                         }
2537
2538                 } else if (test_bit(Faulty, &rdev->flags))
2539                         pr_debug("md: %s (skipping faulty)\n",
2540                                  bdevname(rdev->bdev, b));
2541                 else
2542                         pr_debug("(skipping incremental s/r ");
2543
2544                 if (mddev->level == LEVEL_MULTIPATH)
2545                         /* only need to write one superblock... */
2546                         break;
2547         }
2548         md_super_wait(mddev);
2549         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2550
2551         spin_lock_irq(&mddev->write_lock);
2552         if (mddev->in_sync != sync_req ||
2553             test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2554                 /* have to write it out again */
2555                 spin_unlock_irq(&mddev->write_lock);
2556                 goto repeat;
2557         }
2558         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2559         spin_unlock_irq(&mddev->write_lock);
2560         wake_up(&mddev->sb_wait);
2561         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2562                 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2563
2564         rdev_for_each(rdev, mddev) {
2565                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2566                         clear_bit(Blocked, &rdev->flags);
2567
2568                 if (any_badblocks_changed)
2569                         md_ack_all_badblocks(&rdev->badblocks);
2570                 clear_bit(BlockedBadBlocks, &rdev->flags);
2571                 wake_up(&rdev->blocked_wait);
2572         }
2573 }
2574
2575 /* words written to sysfs files may, or may not, be \n terminated.
2576  * We want to accept with case. For this we use cmd_match.
2577  */
2578 static int cmd_match(const char *cmd, const char *str)
2579 {
2580         /* See if cmd, written into a sysfs file, matches
2581          * str.  They must either be the same, or cmd can
2582          * have a trailing newline
2583          */
2584         while (*cmd && *str && *cmd == *str) {
2585                 cmd++;
2586                 str++;
2587         }
2588         if (*cmd == '\n')
2589                 cmd++;
2590         if (*str || *cmd)
2591                 return 0;
2592         return 1;
2593 }
2594
2595 struct rdev_sysfs_entry {
2596         struct attribute attr;
2597         ssize_t (*show)(struct md_rdev *, char *);
2598         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2599 };
2600
2601 static ssize_t
2602 state_show(struct md_rdev *rdev, char *page)
2603 {
2604         char *sep = "";
2605         size_t len = 0;
2606
2607         if (test_bit(Faulty, &rdev->flags) ||
2608             rdev->badblocks.unacked_exist) {
2609                 len+= sprintf(page+len, "%sfaulty",sep);
2610                 sep = ",";
2611         }
2612         if (test_bit(In_sync, &rdev->flags)) {
2613                 len += sprintf(page+len, "%sin_sync",sep);
2614                 sep = ",";
2615         }
2616         if (test_bit(WriteMostly, &rdev->flags)) {
2617                 len += sprintf(page+len, "%swrite_mostly",sep);
2618                 sep = ",";
2619         }
2620         if (test_bit(Blocked, &rdev->flags) ||
2621             (rdev->badblocks.unacked_exist
2622              && !test_bit(Faulty, &rdev->flags))) {
2623                 len += sprintf(page+len, "%sblocked", sep);
2624                 sep = ",";
2625         }
2626         if (!test_bit(Faulty, &rdev->flags) &&
2627             !test_bit(In_sync, &rdev->flags)) {
2628                 len += sprintf(page+len, "%sspare", sep);
2629                 sep = ",";
2630         }
2631         if (test_bit(WriteErrorSeen, &rdev->flags)) {
2632                 len += sprintf(page+len, "%swrite_error", sep);
2633                 sep = ",";
2634         }
2635         if (test_bit(WantReplacement, &rdev->flags)) {
2636                 len += sprintf(page+len, "%swant_replacement", sep);
2637                 sep = ",";
2638         }
2639         if (test_bit(Replacement, &rdev->flags)) {
2640                 len += sprintf(page+len, "%sreplacement", sep);
2641                 sep = ",";
2642         }
2643
2644         return len+sprintf(page+len, "\n");
2645 }
2646
2647 static ssize_t
2648 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2649 {
2650         /* can write
2651          *  faulty  - simulates an error
2652          *  remove  - disconnects the device
2653          *  writemostly - sets write_mostly
2654          *  -writemostly - clears write_mostly
2655          *  blocked - sets the Blocked flags
2656          *  -blocked - clears the Blocked and possibly simulates an error
2657          *  insync - sets Insync providing device isn't active
2658          *  write_error - sets WriteErrorSeen
2659          *  -write_error - clears WriteErrorSeen
2660          */
2661         int err = -EINVAL;
2662         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2663                 md_error(rdev->mddev, rdev);
2664                 if (test_bit(Faulty, &rdev->flags))
2665                         err = 0;
2666                 else
2667                         err = -EBUSY;
2668         } else if (cmd_match(buf, "remove")) {
2669                 if (rdev->raid_disk >= 0)
2670                         err = -EBUSY;
2671                 else {
2672                         struct mddev *mddev = rdev->mddev;
2673                         kick_rdev_from_array(rdev);
2674                         if (mddev->pers)
2675                                 md_update_sb(mddev, 1);
2676                         md_new_event(mddev);
2677                         err = 0;
2678                 }
2679         } else if (cmd_match(buf, "writemostly")) {
2680                 set_bit(WriteMostly, &rdev->flags);
2681                 err = 0;
2682         } else if (cmd_match(buf, "-writemostly")) {
2683                 clear_bit(WriteMostly, &rdev->flags);
2684                 err = 0;
2685         } else if (cmd_match(buf, "blocked")) {
2686                 set_bit(Blocked, &rdev->flags);
2687                 err = 0;
2688         } else if (cmd_match(buf, "-blocked")) {
2689                 if (!test_bit(Faulty, &rdev->flags) &&
2690                     rdev->badblocks.unacked_exist) {
2691                         /* metadata handler doesn't understand badblocks,
2692                          * so we need to fail the device
2693                          */
2694                         md_error(rdev->mddev, rdev);
2695                 }
2696                 clear_bit(Blocked, &rdev->flags);
2697                 clear_bit(BlockedBadBlocks, &rdev->flags);
2698                 wake_up(&rdev->blocked_wait);
2699                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2700                 md_wakeup_thread(rdev->mddev->thread);
2701
2702                 err = 0;
2703         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2704                 set_bit(In_sync, &rdev->flags);
2705                 err = 0;
2706         } else if (cmd_match(buf, "write_error")) {
2707                 set_bit(WriteErrorSeen, &rdev->flags);
2708                 err = 0;
2709         } else if (cmd_match(buf, "-write_error")) {
2710                 clear_bit(WriteErrorSeen, &rdev->flags);
2711                 err = 0;
2712         } else if (cmd_match(buf, "want_replacement")) {
2713                 /* Any non-spare device that is not a replacement can
2714                  * become want_replacement at any time, but we then need to
2715                  * check if recovery is needed.
2716                  */
2717                 if (rdev->raid_disk >= 0 &&
2718                     !test_bit(Replacement, &rdev->flags))
2719                         set_bit(WantReplacement, &rdev->flags);
2720                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2721                 md_wakeup_thread(rdev->mddev->thread);
2722                 err = 0;
2723         } else if (cmd_match(buf, "-want_replacement")) {
2724                 /* Clearing 'want_replacement' is always allowed.
2725                  * Once replacements starts it is too late though.
2726                  */
2727                 err = 0;
2728                 clear_bit(WantReplacement, &rdev->flags);
2729         } else if (cmd_match(buf, "replacement")) {
2730                 /* Can only set a device as a replacement when array has not
2731                  * yet been started.  Once running, replacement is automatic
2732                  * from spares, or by assigning 'slot'.
2733                  */
2734                 if (rdev->mddev->pers)
2735                         err = -EBUSY;
2736                 else {
2737                         set_bit(Replacement, &rdev->flags);
2738                         err = 0;
2739                 }
2740         } else if (cmd_match(buf, "-replacement")) {
2741                 /* Similarly, can only clear Replacement before start */
2742                 if (rdev->mddev->pers)
2743                         err = -EBUSY;
2744                 else {
2745                         clear_bit(Replacement, &rdev->flags);
2746                         err = 0;
2747                 }
2748         }
2749         if (!err)
2750                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2751         return err ? err : len;
2752 }
2753 static struct rdev_sysfs_entry rdev_state =
2754 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2755
2756 static ssize_t
2757 errors_show(struct md_rdev *rdev, char *page)
2758 {
2759         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2760 }
2761
2762 static ssize_t
2763 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2764 {
2765         char *e;
2766         unsigned long n = simple_strtoul(buf, &e, 10);
2767         if (*buf && (*e == 0 || *e == '\n')) {
2768                 atomic_set(&rdev->corrected_errors, n);
2769                 return len;
2770         }
2771         return -EINVAL;
2772 }
2773 static struct rdev_sysfs_entry rdev_errors =
2774 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2775
2776 static ssize_t
2777 slot_show(struct md_rdev *rdev, char *page)
2778 {
2779         if (rdev->raid_disk < 0)
2780                 return sprintf(page, "none\n");
2781         else
2782                 return sprintf(page, "%d\n", rdev->raid_disk);
2783 }
2784
2785 static ssize_t
2786 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2787 {
2788         char *e;
2789         int err;
2790         int slot = simple_strtoul(buf, &e, 10);
2791         if (strncmp(buf, "none", 4)==0)
2792                 slot = -1;
2793         else if (e==buf || (*e && *e!= '\n'))
2794                 return -EINVAL;
2795         if (rdev->mddev->pers && slot == -1) {
2796                 /* Setting 'slot' on an active array requires also
2797                  * updating the 'rd%d' link, and communicating
2798                  * with the personality with ->hot_*_disk.
2799                  * For now we only support removing
2800                  * failed/spare devices.  This normally happens automatically,
2801                  * but not when the metadata is externally managed.
2802                  */
2803                 if (rdev->raid_disk == -1)
2804                         return -EEXIST;
2805                 /* personality does all needed checks */
2806                 if (rdev->mddev->pers->hot_remove_disk == NULL)
2807                         return -EINVAL;
2808                 err = rdev->mddev->pers->
2809                         hot_remove_disk(rdev->mddev, rdev);
2810                 if (err)
2811                         return err;
2812                 sysfs_unlink_rdev(rdev->mddev, rdev);
2813                 rdev->raid_disk = -1;
2814                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2815                 md_wakeup_thread(rdev->mddev->thread);
2816         } else if (rdev->mddev->pers) {
2817                 /* Activating a spare .. or possibly reactivating
2818                  * if we ever get bitmaps working here.
2819                  */
2820
2821                 if (rdev->raid_disk != -1)
2822                         return -EBUSY;
2823
2824                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2825                         return -EBUSY;
2826
2827                 if (rdev->mddev->pers->hot_add_disk == NULL)
2828                         return -EINVAL;
2829
2830                 if (slot >= rdev->mddev->raid_disks &&
2831                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2832                         return -ENOSPC;
2833
2834                 rdev->raid_disk = slot;
2835                 if (test_bit(In_sync, &rdev->flags))
2836                         rdev->saved_raid_disk = slot;
2837                 else
2838                         rdev->saved_raid_disk = -1;
2839                 clear_bit(In_sync, &rdev->flags);
2840                 err = rdev->mddev->pers->
2841                         hot_add_disk(rdev->mddev, rdev);
2842                 if (err) {
2843                         rdev->raid_disk = -1;
2844                         return err;
2845                 } else
2846                         sysfs_notify_dirent_safe(rdev->sysfs_state);
2847                 if (sysfs_link_rdev(rdev->mddev, rdev))
2848                         /* failure here is OK */;
2849                 /* don't wakeup anyone, leave that to userspace. */
2850         } else {
2851                 if (slot >= rdev->mddev->raid_disks &&
2852                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2853                         return -ENOSPC;
2854                 rdev->raid_disk = slot;
2855                 /* assume it is working */
2856                 clear_bit(Faulty, &rdev->flags);
2857                 clear_bit(WriteMostly, &rdev->flags);
2858                 set_bit(In_sync, &rdev->flags);
2859                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2860         }
2861         return len;
2862 }
2863
2864
2865 static struct rdev_sysfs_entry rdev_slot =
2866 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2867
2868 static ssize_t
2869 offset_show(struct md_rdev *rdev, char *page)
2870 {
2871         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2872 }
2873
2874 static ssize_t
2875 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2876 {
2877         unsigned long long offset;
2878         if (strict_strtoull(buf, 10, &offset) < 0)
2879                 return -EINVAL;
2880         if (rdev->mddev->pers && rdev->raid_disk >= 0)
2881                 return -EBUSY;
2882         if (rdev->sectors && rdev->mddev->external)
2883                 /* Must set offset before size, so overlap checks
2884                  * can be sane */
2885                 return -EBUSY;
2886         rdev->data_offset = offset;
2887         rdev->new_data_offset = offset;
2888         return len;
2889 }
2890
2891 static struct rdev_sysfs_entry rdev_offset =
2892 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2893
2894 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2895 {
2896         return sprintf(page, "%llu\n",
2897                        (unsigned long long)rdev->new_data_offset);
2898 }
2899
2900 static ssize_t new_offset_store(struct md_rdev *rdev,
2901                                 const char *buf, size_t len)
2902 {
2903         unsigned long long new_offset;
2904         struct mddev *mddev = rdev->mddev;
2905
2906         if (strict_strtoull(buf, 10, &new_offset) < 0)
2907                 return -EINVAL;
2908
2909         if (mddev->sync_thread)
2910                 return -EBUSY;
2911         if (new_offset == rdev->data_offset)
2912                 /* reset is always permitted */
2913                 ;
2914         else if (new_offset > rdev->data_offset) {
2915                 /* must not push array size beyond rdev_sectors */
2916                 if (new_offset - rdev->data_offset
2917                     + mddev->dev_sectors > rdev->sectors)
2918                                 return -E2BIG;
2919         }
2920         /* Metadata worries about other space details. */
2921
2922         /* decreasing the offset is inconsistent with a backwards
2923          * reshape.
2924          */
2925         if (new_offset < rdev->data_offset &&
2926             mddev->reshape_backwards)
2927                 return -EINVAL;
2928         /* Increasing offset is inconsistent with forwards
2929          * reshape.  reshape_direction should be set to
2930          * 'backwards' first.
2931          */
2932         if (new_offset > rdev->data_offset &&
2933             !mddev->reshape_backwards)
2934                 return -EINVAL;
2935
2936         if (mddev->pers && mddev->persistent &&
2937             !super_types[mddev->major_version]
2938             .allow_new_offset(rdev, new_offset))
2939                 return -E2BIG;
2940         rdev->new_data_offset = new_offset;
2941         if (new_offset > rdev->data_offset)
2942                 mddev->reshape_backwards = 1;
2943         else if (new_offset < rdev->data_offset)
2944                 mddev->reshape_backwards = 0;
2945
2946         return len;
2947 }
2948 static struct rdev_sysfs_entry rdev_new_offset =
2949 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2950
2951 static ssize_t
2952 rdev_size_show(struct md_rdev *rdev, char *page)
2953 {
2954         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2955 }
2956
2957 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2958 {
2959         /* check if two start/length pairs overlap */
2960         if (s1+l1 <= s2)
2961                 return 0;
2962         if (s2+l2 <= s1)
2963                 return 0;
2964         return 1;
2965 }
2966
2967 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2968 {
2969         unsigned long long blocks;
2970         sector_t new;
2971
2972         if (strict_strtoull(buf, 10, &blocks) < 0)
2973                 return -EINVAL;
2974
2975         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2976                 return -EINVAL; /* sector conversion overflow */
2977
2978         new = blocks * 2;
2979         if (new != blocks * 2)
2980                 return -EINVAL; /* unsigned long long to sector_t overflow */
2981
2982         *sectors = new;
2983         return 0;
2984 }
2985
2986 static ssize_t
2987 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2988 {
2989         struct mddev *my_mddev = rdev->mddev;
2990         sector_t oldsectors = rdev->sectors;
2991         sector_t sectors;
2992
2993         if (strict_blocks_to_sectors(buf, &sectors) < 0)
2994                 return -EINVAL;
2995         if (rdev->data_offset != rdev->new_data_offset)
2996                 return -EINVAL; /* too confusing */
2997         if (my_mddev->pers && rdev->raid_disk >= 0) {
2998                 if (my_mddev->persistent) {
2999                         sectors = super_types[my_mddev->major_version].
3000                                 rdev_size_change(rdev, sectors);
3001                         if (!sectors)
3002                                 return -EBUSY;
3003                 } else if (!sectors)
3004                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
3005                                 rdev->data_offset;
3006                 if (!my_mddev->pers->resize)
3007                         /* Cannot change size for RAID0 or Linear etc */
3008                         return -EINVAL;
3009         }
3010         if (sectors < my_mddev->dev_sectors)
3011                 return -EINVAL; /* component must fit device */
3012
3013         rdev->sectors = sectors;
3014         if (sectors > oldsectors && my_mddev->external) {
3015                 /* need to check that all other rdevs with the same ->bdev
3016                  * do not overlap.  We need to unlock the mddev to avoid
3017                  * a deadlock.  We have already changed rdev->sectors, and if
3018                  * we have to change it back, we will have the lock again.
3019                  */
3020                 struct mddev *mddev;
3021                 int overlap = 0;
3022                 struct list_head *tmp;
3023
3024                 mddev_unlock(my_mddev);
3025                 for_each_mddev(mddev, tmp) {
3026                         struct md_rdev *rdev2;
3027
3028                         mddev_lock(mddev);
3029                         rdev_for_each(rdev2, mddev)
3030                                 if (rdev->bdev == rdev2->bdev &&
3031                                     rdev != rdev2 &&
3032                                     overlaps(rdev->data_offset, rdev->sectors,
3033                                              rdev2->data_offset,
3034                                              rdev2->sectors)) {
3035                                         overlap = 1;
3036                                         break;
3037                                 }
3038                         mddev_unlock(mddev);
3039                         if (overlap) {
3040                                 mddev_put(mddev);
3041                                 break;
3042                         }
3043                 }
3044                 mddev_lock(my_mddev);
3045                 if (overlap) {
3046                         /* Someone else could have slipped in a size
3047                          * change here, but doing so is just silly.
3048                          * We put oldsectors back because we *know* it is
3049                          * safe, and trust userspace not to race with
3050                          * itself
3051                          */
3052                         rdev->sectors = oldsectors;
3053                         return -EBUSY;
3054                 }
3055         }
3056         return len;
3057 }
3058
3059 static struct rdev_sysfs_entry rdev_size =
3060 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3061
3062
3063 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3064 {
3065         unsigned long long recovery_start = rdev->recovery_offset;
3066
3067         if (test_bit(In_sync, &rdev->flags) ||
3068             recovery_start == MaxSector)
3069                 return sprintf(page, "none\n");
3070
3071         return sprintf(page, "%llu\n", recovery_start);
3072 }
3073
3074 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3075 {
3076         unsigned long long recovery_start;
3077
3078         if (cmd_match(buf, "none"))
3079                 recovery_start = MaxSector;
3080         else if (strict_strtoull(buf, 10, &recovery_start))
3081                 return -EINVAL;
3082
3083         if (rdev->mddev->pers &&
3084             rdev->raid_disk >= 0)
3085                 return -EBUSY;
3086
3087         rdev->recovery_offset = recovery_start;
3088         if (recovery_start == MaxSector)
3089                 set_bit(In_sync, &rdev->flags);
3090         else
3091                 clear_bit(In_sync, &rdev->flags);
3092         return len;
3093 }
3094
3095 static struct rdev_sysfs_entry rdev_recovery_start =
3096 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3097
3098
3099 static ssize_t
3100 badblocks_show(struct badblocks *bb, char *page, int unack);
3101 static ssize_t
3102 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
3103
3104 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3105 {
3106         return badblocks_show(&rdev->badblocks, page, 0);
3107 }
3108 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3109 {
3110         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3111         /* Maybe that ack was all we needed */
3112         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3113                 wake_up(&rdev->blocked_wait);
3114         return rv;
3115 }
3116 static struct rdev_sysfs_entry rdev_bad_blocks =
3117 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3118
3119
3120 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3121 {
3122         return badblocks_show(&rdev->badblocks, page, 1);
3123 }
3124 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3125 {
3126         return badblocks_store(&rdev->badblocks, page, len, 1);
3127 }
3128 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3129 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3130
3131 static struct attribute *rdev_default_attrs[] = {
3132         &rdev_state.attr,
3133         &rdev_errors.attr,
3134         &rdev_slot.attr,
3135         &rdev_offset.attr,
3136         &rdev_new_offset.attr,
3137         &rdev_size.attr,
3138         &rdev_recovery_start.attr,
3139         &rdev_bad_blocks.attr,
3140         &rdev_unack_bad_blocks.attr,
3141         NULL,
3142 };
3143 static ssize_t
3144 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3145 {
3146         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3147         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3148         struct mddev *mddev = rdev->mddev;
3149         ssize_t rv;
3150
3151         if (!entry->show)
3152                 return -EIO;
3153
3154         rv = mddev ? mddev_lock(mddev) : -EBUSY;
3155         if (!rv) {
3156                 if (rdev->mddev == NULL)
3157                         rv = -EBUSY;
3158                 else
3159                         rv = entry->show(rdev, page);
3160                 mddev_unlock(mddev);
3161         }
3162         return rv;
3163 }
3164
3165 static ssize_t
3166 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3167               const char *page, size_t length)
3168 {
3169         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3170         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3171         ssize_t rv;
3172         struct mddev *mddev = rdev->mddev;
3173
3174         if (!entry->store)
3175                 return -EIO;
3176         if (!capable(CAP_SYS_ADMIN))
3177                 return -EACCES;
3178         rv = mddev ? mddev_lock(mddev): -EBUSY;
3179         if (!rv) {
3180                 if (rdev->mddev == NULL)
3181                         rv = -EBUSY;
3182                 else
3183                         rv = entry->store(rdev, page, length);
3184                 mddev_unlock(mddev);
3185         }
3186         return rv;
3187 }
3188
3189 static void rdev_free(struct kobject *ko)
3190 {
3191         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3192         kfree(rdev);
3193 }
3194 static const struct sysfs_ops rdev_sysfs_ops = {
3195         .show           = rdev_attr_show,
3196         .store          = rdev_attr_store,
3197 };
3198 static struct kobj_type rdev_ktype = {
3199         .release        = rdev_free,
3200         .sysfs_ops      = &rdev_sysfs_ops,
3201         .default_attrs  = rdev_default_attrs,
3202 };
3203
3204 int md_rdev_init(struct md_rdev *rdev)
3205 {
3206         rdev->desc_nr = -1;
3207         rdev->saved_raid_disk = -1;
3208         rdev->raid_disk = -1;
3209         rdev->flags = 0;
3210         rdev->data_offset = 0;
3211         rdev->new_data_offset = 0;
3212         rdev->sb_events = 0;
3213         rdev->last_read_error.tv_sec  = 0;
3214         rdev->last_read_error.tv_nsec = 0;
3215         rdev->sb_loaded = 0;
3216         rdev->bb_page = NULL;
3217         atomic_set(&rdev->nr_pending, 0);
3218         atomic_set(&rdev->read_errors, 0);
3219         atomic_set(&rdev->corrected_errors, 0);
3220
3221         INIT_LIST_HEAD(&rdev->same_set);
3222         init_waitqueue_head(&rdev->blocked_wait);
3223
3224         /* Add space to store bad block list.
3225          * This reserves the space even on arrays where it cannot
3226          * be used - I wonder if that matters
3227          */
3228         rdev->badblocks.count = 0;
3229         rdev->badblocks.shift = 0;
3230         rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3231         seqlock_init(&rdev->badblocks.lock);
3232         if (rdev->badblocks.page == NULL)
3233                 return -ENOMEM;
3234
3235         return 0;
3236 }
3237 EXPORT_SYMBOL_GPL(md_rdev_init);
3238 /*
3239  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3240  *
3241  * mark the device faulty if:
3242  *
3243  *   - the device is nonexistent (zero size)
3244  *   - the device has no valid superblock
3245  *
3246  * a faulty rdev _never_ has rdev->sb set.
3247  */
3248 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3249 {
3250         char b[BDEVNAME_SIZE];
3251         int err;
3252         struct md_rdev *rdev;
3253         sector_t size;
3254
3255         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3256         if (!rdev) {
3257                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
3258                 return ERR_PTR(-ENOMEM);
3259         }
3260
3261         err = md_rdev_init(rdev);
3262         if (err)
3263                 goto abort_free;
3264         err = alloc_disk_sb(rdev);
3265         if (err)
3266                 goto abort_free;
3267
3268         err = lock_rdev(rdev, newdev, super_format == -2);
3269         if (err)
3270                 goto abort_free;
3271
3272         kobject_init(&rdev->kobj, &rdev_ktype);
3273
3274         size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3275         if (!size) {
3276                 printk(KERN_WARNING 
3277                         "md: %s has zero or unknown size, marking faulty!\n",
3278                         bdevname(rdev->bdev,b));
3279                 err = -EINVAL;
3280                 goto abort_free;
3281         }
3282
3283         if (super_format >= 0) {
3284                 err = super_types[super_format].
3285                         load_super(rdev, NULL, super_minor);
3286                 if (err == -EINVAL) {
3287                         printk(KERN_WARNING
3288                                 "md: %s does not have a valid v%d.%d "
3289                                "superblock, not importing!\n",
3290                                 bdevname(rdev->bdev,b),
3291                                super_format, super_minor);
3292                         goto abort_free;
3293                 }
3294                 if (err < 0) {
3295                         printk(KERN_WARNING 
3296                                 "md: could not read %s's sb, not importing!\n",
3297                                 bdevname(rdev->bdev,b));
3298                         goto abort_free;
3299                 }
3300         }
3301         if (super_format == -1)
3302                 /* hot-add for 0.90, or non-persistent: so no badblocks */
3303                 rdev->badblocks.shift = -1;
3304
3305         return rdev;
3306
3307 abort_free:
3308         if (rdev->bdev)
3309                 unlock_rdev(rdev);
3310         md_rdev_clear(rdev);
3311         kfree(rdev);
3312         return ERR_PTR(err);
3313 }
3314
3315 /*
3316  * Check a full RAID array for plausibility
3317  */
3318
3319
3320 static void analyze_sbs(struct mddev * mddev)
3321 {
3322         int i;
3323         struct md_rdev *rdev, *freshest, *tmp;
3324         char b[BDEVNAME_SIZE];
3325
3326         freshest = NULL;
3327         rdev_for_each_safe(rdev, tmp, mddev)
3328                 switch (super_types[mddev->major_version].
3329                         load_super(rdev, freshest, mddev->minor_version)) {
3330                 case 1:
3331                         freshest = rdev;
3332                         break;
3333                 case 0:
3334                         break;
3335                 default:
3336                         printk( KERN_ERR \
3337                                 "md: fatal superblock inconsistency in %s"
3338                                 " -- removing from array\n", 
3339                                 bdevname(rdev->bdev,b));
3340                         kick_rdev_from_array(rdev);
3341                 }
3342
3343
3344         super_types[mddev->major_version].
3345                 validate_super(mddev, freshest);
3346
3347         i = 0;
3348         rdev_for_each_safe(rdev, tmp, mddev) {
3349                 if (mddev->max_disks &&
3350                     (rdev->desc_nr >= mddev->max_disks ||
3351                      i > mddev->max_disks)) {
3352                         printk(KERN_WARNING
3353                                "md: %s: %s: only %d devices permitted\n",
3354                                mdname(mddev), bdevname(rdev->bdev, b),
3355                                mddev->max_disks);
3356                         kick_rdev_from_array(rdev);
3357                         continue;
3358                 }
3359                 if (rdev != freshest)
3360                         if (super_types[mddev->major_version].
3361                             validate_super(mddev, rdev)) {
3362                                 printk(KERN_WARNING "md: kicking non-fresh %s"
3363                                         " from array!\n",
3364                                         bdevname(rdev->bdev,b));
3365                                 kick_rdev_from_array(rdev);
3366                                 continue;
3367                         }
3368                 if (mddev->level == LEVEL_MULTIPATH) {
3369                         rdev->desc_nr = i++;
3370                         rdev->raid_disk = rdev->desc_nr;
3371                         set_bit(In_sync, &rdev->flags);
3372                 } else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3373                         rdev->raid_disk = -1;
3374                         clear_bit(In_sync, &rdev->flags);
3375                 }
3376         }
3377 }
3378
3379 /* Read a fixed-point number.
3380  * Numbers in sysfs attributes should be in "standard" units where
3381  * possible, so time should be in seconds.
3382  * However we internally use a a much smaller unit such as 
3383  * milliseconds or jiffies.
3384  * This function takes a decimal number with a possible fractional
3385  * component, and produces an integer which is the result of
3386  * multiplying that number by 10^'scale'.
3387  * all without any floating-point arithmetic.
3388  */
3389 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3390 {
3391         unsigned long result = 0;
3392         long decimals = -1;
3393         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3394                 if (*cp == '.')
3395                         decimals = 0;
3396                 else if (decimals < scale) {
3397                         unsigned int value;
3398                         value = *cp - '0';
3399                         result = result * 10 + value;
3400                         if (decimals >= 0)
3401                                 decimals++;
3402                 }
3403                 cp++;
3404         }
3405         if (*cp == '\n')
3406                 cp++;
3407         if (*cp)
3408                 return -EINVAL;
3409         if (decimals < 0)
3410                 decimals = 0;
3411         while (decimals < scale) {
3412                 result *= 10;
3413                 decimals ++;
3414         }
3415         *res = result;
3416         return 0;
3417 }
3418
3419
3420 static void md_safemode_timeout(unsigned long data);
3421
3422 static ssize_t
3423 safe_delay_show(struct mddev *mddev, char *page)
3424 {
3425         int msec = (mddev->safemode_delay*1000)/HZ;
3426         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3427 }
3428 static ssize_t
3429 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3430 {
3431         unsigned long msec;
3432
3433         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3434                 return -EINVAL;
3435         if (msec == 0)
3436                 mddev->safemode_delay = 0;
3437         else {
3438                 unsigned long old_delay = mddev->safemode_delay;
3439                 mddev->safemode_delay = (msec*HZ)/1000;
3440                 if (mddev->safemode_delay == 0)
3441                         mddev->safemode_delay = 1;
3442                 if (mddev->safemode_delay < old_delay)
3443                         md_safemode_timeout((unsigned long)mddev);
3444         }
3445         return len;
3446 }
3447 static struct md_sysfs_entry md_safe_delay =
3448 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3449
3450 static ssize_t
3451 level_show(struct mddev *mddev, char *page)
3452 {
3453         struct md_personality *p = mddev->pers;
3454         if (p)
3455                 return sprintf(page, "%s\n", p->name);
3456         else if (mddev->clevel[0])
3457                 return sprintf(page, "%s\n", mddev->clevel);
3458         else if (mddev->level != LEVEL_NONE)
3459                 return sprintf(page, "%d\n", mddev->level);
3460         else
3461                 return 0;
3462 }
3463
3464 static ssize_t
3465 level_store(struct mddev *mddev, const char *buf, size_t len)
3466 {
3467         char clevel[16];
3468         ssize_t rv = len;
3469         struct md_personality *pers;
3470         long level;
3471         void *priv;
3472         struct md_rdev *rdev;
3473
3474         if (mddev->pers == NULL) {
3475                 if (len == 0)
3476                         return 0;
3477                 if (len >= sizeof(mddev->clevel))
3478                         return -ENOSPC;
3479                 strncpy(mddev->clevel, buf, len);
3480                 if (mddev->clevel[len-1] == '\n')
3481                         len--;
3482                 mddev->clevel[len] = 0;
3483                 mddev->level = LEVEL_NONE;
3484                 return rv;
3485         }
3486
3487         /* request to change the personality.  Need to ensure:
3488          *  - array is not engaged in resync/recovery/reshape
3489          *  - old personality can be suspended
3490          *  - new personality will access other array.
3491          */
3492
3493         if (mddev->sync_thread ||
3494             mddev->reshape_position != MaxSector ||
3495             mddev->sysfs_active)
3496                 return -EBUSY;
3497
3498         if (!mddev->pers->quiesce) {
3499                 printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3500                        mdname(mddev), mddev->pers->name);
3501                 return -EINVAL;
3502         }
3503
3504         /* Now find the new personality */
3505         if (len == 0 || len >= sizeof(clevel))
3506                 return -EINVAL;
3507         strncpy(clevel, buf, len);
3508         if (clevel[len-1] == '\n')
3509                 len--;
3510         clevel[len] = 0;
3511         if (strict_strtol(clevel, 10, &level))
3512                 level = LEVEL_NONE;
3513
3514         if (request_module("md-%s", clevel) != 0)
3515                 request_module("md-level-%s", clevel);
3516         spin_lock(&pers_lock);
3517         pers = find_pers(level, clevel);
3518         if (!pers || !try_module_get(pers->owner)) {
3519                 spin_unlock(&pers_lock);
3520                 printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3521                 return -EINVAL;
3522         }
3523         spin_unlock(&pers_lock);
3524
3525         if (pers == mddev->pers) {
3526                 /* Nothing to do! */
3527                 module_put(pers->owner);
3528                 return rv;
3529         }
3530         if (!pers->takeover) {
3531                 module_put(pers->owner);
3532                 printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3533                        mdname(mddev), clevel);
3534                 return -EINVAL;
3535         }
3536
3537         rdev_for_each(rdev, mddev)
3538                 rdev->new_raid_disk = rdev->raid_disk;
3539
3540         /* ->takeover must set new_* and/or delta_disks
3541          * if it succeeds, and may set them when it fails.
3542          */
3543         priv = pers->takeover(mddev);
3544         if (IS_ERR(priv)) {
3545                 mddev->new_level = mddev->level;
3546                 mddev->new_layout = mddev->layout;
3547                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3548                 mddev->raid_disks -= mddev->delta_disks;
3549                 mddev->delta_disks = 0;
3550                 mddev->reshape_backwards = 0;
3551                 module_put(pers->owner);
3552                 printk(KERN_WARNING "md: %s: %s would not accept array\n",
3553                        mdname(mddev), clevel);
3554                 return PTR_ERR(priv);
3555         }
3556
3557         /* Looks like we have a winner */
3558         mddev_suspend(mddev);
3559         mddev->pers->stop(mddev);
3560         
3561         if (mddev->pers->sync_request == NULL &&
3562             pers->sync_request != NULL) {
3563                 /* need to add the md_redundancy_group */
3564                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3565                         printk(KERN_WARNING
3566                                "md: cannot register extra attributes for %s\n",
3567                                mdname(mddev));
3568                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3569         }               
3570         if (mddev->pers->sync_request != NULL &&
3571             pers->sync_request == NULL) {
3572                 /* need to remove the md_redundancy_group */
3573                 if (mddev->to_remove == NULL)
3574                         mddev->to_remove = &md_redundancy_group;
3575         }
3576
3577         if (mddev->pers->sync_request == NULL &&
3578             mddev->external) {
3579                 /* We are converting from a no-redundancy array
3580                  * to a redundancy array and metadata is managed
3581                  * externally so we need to be sure that writes
3582                  * won't block due to a need to transition
3583                  *      clean->dirty
3584                  * until external management is started.
3585                  */
3586                 mddev->in_sync = 0;
3587                 mddev->safemode_delay = 0;
3588                 mddev->safemode = 0;
3589         }
3590
3591         rdev_for_each(rdev, mddev) {
3592                 if (rdev->raid_disk < 0)
3593                         continue;
3594                 if (rdev->new_raid_disk >= mddev->raid_disks)
3595                         rdev->new_raid_disk = -1;
3596                 if (rdev->new_raid_disk == rdev->raid_disk)
3597                         continue;
3598                 sysfs_unlink_rdev(mddev, rdev);
3599         }
3600         rdev_for_each(rdev, mddev) {
3601                 if (rdev->raid_disk < 0)
3602                         continue;
3603                 if (rdev->new_raid_disk == rdev->raid_disk)
3604                         continue;
3605                 rdev->raid_disk = rdev->new_raid_disk;
3606                 if (rdev->raid_disk < 0)
3607                         clear_bit(In_sync, &rdev->flags);
3608                 else {
3609                         if (sysfs_link_rdev(mddev, rdev))
3610                                 printk(KERN_WARNING "md: cannot register rd%d"
3611                                        " for %s after level change\n",
3612                                        rdev->raid_disk, mdname(mddev));
3613                 }
3614         }
3615
3616         module_put(mddev->pers->owner);
3617         mddev->pers = pers;
3618         mddev->private = priv;
3619         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3620         mddev->level = mddev->new_level;
3621         mddev->layout = mddev->new_layout;
3622         mddev->chunk_sectors = mddev->new_chunk_sectors;
3623         mddev->delta_disks = 0;
3624         mddev->reshape_backwards = 0;
3625         mddev->degraded = 0;
3626         if (mddev->pers->sync_request == NULL) {
3627                 /* this is now an array without redundancy, so
3628                  * it must always be in_sync
3629                  */
3630                 mddev->in_sync = 1;
3631                 del_timer_sync(&mddev->safemode_timer);
3632         }
3633         pers->run(mddev);
3634         set_bit(MD_CHANGE_DEVS, &mddev->flags);
3635         mddev_resume(mddev);
3636         sysfs_notify(&mddev->kobj, NULL, "level");
3637         md_new_event(mddev);
3638         return rv;
3639 }
3640
3641 static struct md_sysfs_entry md_level =
3642 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3643
3644
3645 static ssize_t
3646 layout_show(struct mddev *mddev, char *page)
3647 {
3648         /* just a number, not meaningful for all levels */
3649         if (mddev->reshape_position != MaxSector &&
3650             mddev->layout != mddev->new_layout)
3651                 return sprintf(page, "%d (%d)\n",
3652                                mddev->new_layout, mddev->layout);
3653         return sprintf(page, "%d\n", mddev->layout);
3654 }
3655
3656 static ssize_t
3657 layout_store(struct mddev *mddev, const char *buf, size_t len)
3658 {
3659         char *e;
3660         unsigned long n = simple_strtoul(buf, &e, 10);
3661
3662         if (!*buf || (*e && *e != '\n'))
3663                 return -EINVAL;
3664
3665         if (mddev->pers) {
3666                 int err;
3667                 if (mddev->pers->check_reshape == NULL)
3668                         return -EBUSY;
3669                 mddev->new_layout = n;
3670                 err = mddev->pers->check_reshape(mddev);
3671                 if (err) {
3672                         mddev->new_layout = mddev->layout;
3673                         return err;
3674                 }
3675         } else {
3676                 mddev->new_layout = n;
3677                 if (mddev->reshape_position == MaxSector)
3678                         mddev->layout = n;
3679         }
3680         return len;
3681 }
3682 static struct md_sysfs_entry md_layout =
3683 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3684
3685
3686 static ssize_t
3687 raid_disks_show(struct mddev *mddev, char *page)
3688 {
3689         if (mddev->raid_disks == 0)
3690                 return 0;
3691         if (mddev->reshape_position != MaxSector &&
3692             mddev->delta_disks != 0)
3693                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3694                                mddev->raid_disks - mddev->delta_disks);
3695         return sprintf(page, "%d\n", mddev->raid_disks);
3696 }
3697
3698 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3699
3700 static ssize_t
3701 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3702 {
3703         char *e;
3704         int rv = 0;
3705         unsigned long n = simple_strtoul(buf, &e, 10);
3706
3707         if (!*buf || (*e && *e != '\n'))
3708                 return -EINVAL;
3709
3710         if (mddev->pers)
3711                 rv = update_raid_disks(mddev, n);
3712         else if (mddev->reshape_position != MaxSector) {
3713                 struct md_rdev *rdev;
3714                 int olddisks = mddev->raid_disks - mddev->delta_disks;
3715
3716                 rdev_for_each(rdev, mddev) {
3717                         if (olddisks < n &&
3718                             rdev->data_offset < rdev->new_data_offset)
3719                                 return -EINVAL;
3720                         if (olddisks > n &&
3721                             rdev->data_offset > rdev->new_data_offset)
3722                                 return -EINVAL;
3723                 }
3724                 mddev->delta_disks = n - olddisks;
3725                 mddev->raid_disks = n;
3726                 mddev->reshape_backwards = (mddev->delta_disks < 0);
3727         } else
3728                 mddev->raid_disks = n;
3729         return rv ? rv : len;
3730 }
3731 static struct md_sysfs_entry md_raid_disks =
3732 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3733
3734 static ssize_t
3735 chunk_size_show(struct mddev *mddev, char *page)
3736 {
3737         if (mddev->reshape_position != MaxSector &&
3738             mddev->chunk_sectors != mddev->new_chunk_sectors)
3739                 return sprintf(page, "%d (%d)\n",
3740                                mddev->new_chunk_sectors << 9,
3741                                mddev->chunk_sectors << 9);
3742         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3743 }
3744
3745 static ssize_t
3746 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3747 {
3748         char *e;
3749         unsigned long n = simple_strtoul(buf, &e, 10);
3750
3751         if (!*buf || (*e && *e != '\n'))
3752                 return -EINVAL;
3753
3754         if (mddev->pers) {
3755                 int err;
3756                 if (mddev->pers->check_reshape == NULL)
3757                         return -EBUSY;
3758                 mddev->new_chunk_sectors = n >> 9;
3759                 err = mddev->pers->check_reshape(mddev);
3760                 if (err) {
3761                         mddev->new_chunk_sectors = mddev->chunk_sectors;
3762                         return err;
3763                 }
3764         } else {
3765                 mddev->new_chunk_sectors = n >> 9;
3766                 if (mddev->reshape_position == MaxSector)
3767                         mddev->chunk_sectors = n >> 9;
3768         }
3769         return len;
3770 }
3771 static struct md_sysfs_entry md_chunk_size =
3772 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3773
3774 static ssize_t
3775 resync_start_show(struct mddev *mddev, char *page)
3776 {
3777         if (mddev->recovery_cp == MaxSector)
3778                 return sprintf(page, "none\n");
3779         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3780 }
3781
3782 static ssize_t
3783 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3784 {
3785         char *e;
3786         unsigned long long n = simple_strtoull(buf, &e, 10);
3787
3788         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3789                 return -EBUSY;
3790         if (cmd_match(buf, "none"))
3791                 n = MaxSector;
3792         else if (!*buf || (*e && *e != '\n'))
3793                 return -EINVAL;
3794
3795         mddev->recovery_cp = n;
3796         if (mddev->pers)
3797                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3798         return len;
3799 }
3800 static struct md_sysfs_entry md_resync_start =
3801 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3802
3803 /*
3804  * The array state can be:
3805  *
3806  * clear
3807  *     No devices, no size, no level
3808  *     Equivalent to STOP_ARRAY ioctl
3809  * inactive
3810  *     May have some settings, but array is not active
3811  *        all IO results in error
3812  *     When written, doesn't tear down array, but just stops it
3813  * suspended (not supported yet)
3814  *     All IO requests will block. The array can be reconfigured.
3815  *     Writing this, if accepted, will block until array is quiescent
3816  * readonly
3817  *     no resync can happen.  no superblocks get written.
3818  *     write requests fail
3819  * read-auto
3820  *     like readonly, but behaves like 'clean' on a write request.
3821  *
3822  * clean - no pending writes, but otherwise active.
3823  *     When written to inactive array, starts without resync
3824  *     If a write request arrives then
3825  *       if metadata is known, mark 'dirty' and switch to 'active'.
3826  *       if not known, block and switch to write-pending
3827  *     If written to an active array that has pending writes, then fails.
3828  * active
3829  *     fully active: IO and resync can be happening.
3830  *     When written to inactive array, starts with resync
3831  *
3832  * write-pending
3833  *     clean, but writes are blocked waiting for 'active' to be written.
3834  *
3835  * active-idle
3836  *     like active, but no writes have been seen for a while (100msec).
3837  *
3838  */
3839 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3840                    write_pending, active_idle, bad_word};
3841 static char *array_states[] = {
3842         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3843         "write-pending", "active-idle", NULL };
3844
3845 static int match_word(const char *word, char **list)
3846 {
3847         int n;
3848         for (n=0; list[n]; n++)
3849                 if (cmd_match(word, list[n]))
3850                         break;
3851         return n;
3852 }
3853
3854 static ssize_t
3855 array_state_show(struct mddev *mddev, char *page)
3856 {
3857         enum array_state st = inactive;
3858
3859         if (mddev->pers)
3860                 switch(mddev->ro) {
3861                 case 1:
3862                         st = readonly;
3863                         break;
3864                 case 2:
3865                         st = read_auto;
3866                         break;
3867                 case 0:
3868                         if (mddev->in_sync)
3869                                 st = clean;
3870                         else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3871                                 st = write_pending;
3872                         else if (mddev->safemode)
3873                                 st = active_idle;
3874                         else
3875                                 st = active;
3876                 }
3877         else {
3878                 if (list_empty(&mddev->disks) &&
3879                     mddev->raid_disks == 0 &&
3880                     mddev->dev_sectors == 0)
3881                         st = clear;
3882                 else
3883                         st = inactive;
3884         }
3885         return sprintf(page, "%s\n", array_states[st]);
3886 }
3887
3888 static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
3889 static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
3890 static int do_md_run(struct mddev * mddev);
3891 static int restart_array(struct mddev *mddev);
3892
3893 static ssize_t
3894 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3895 {
3896         int err = -EINVAL;
3897         enum array_state st = match_word(buf, array_states);
3898         switch(st) {
3899         case bad_word:
3900                 break;
3901         case clear:
3902                 /* stopping an active array */
3903                 err = do_md_stop(mddev, 0, NULL);
3904                 break;
3905         case inactive:
3906                 /* stopping an active array */
3907                 if (mddev->pers)
3908                         err = do_md_stop(mddev, 2, NULL);
3909                 else
3910                         err = 0; /* already inactive */
3911                 break;
3912         case suspended:
3913                 break; /* not supported yet */
3914         case readonly:
3915                 if (mddev->pers)
3916                         err = md_set_readonly(mddev, NULL);
3917                 else {
3918                         mddev->ro = 1;
3919                         set_disk_ro(mddev->gendisk, 1);
3920                         err = do_md_run(mddev);
3921                 }
3922                 break;
3923         case read_auto:
3924                 if (mddev->pers) {
3925                         if (mddev->ro == 0)
3926                                 err = md_set_readonly(mddev, NULL);
3927                         else if (mddev->ro == 1)
3928                                 err = restart_array(mddev);
3929                         if (err == 0) {
3930                                 mddev->ro = 2;
3931                                 set_disk_ro(mddev->gendisk, 0);
3932                         }
3933                 } else {
3934                         mddev->ro = 2;
3935                         err = do_md_run(mddev);
3936                 }
3937                 break;
3938         case clean:
3939                 if (mddev->pers) {
3940                         restart_array(mddev);
3941                         spin_lock_irq(&mddev->write_lock);
3942                         if (atomic_read(&mddev->writes_pending) == 0) {
3943                                 if (mddev->in_sync == 0) {
3944                                         mddev->in_sync = 1;
3945                                         if (mddev->safemode == 1)
3946                                                 mddev->safemode = 0;
3947                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3948                                 }
3949                                 err = 0;
3950                         } else
3951                                 err = -EBUSY;
3952                         spin_unlock_irq(&mddev->write_lock);
3953                 } else
3954                         err = -EINVAL;
3955                 break;
3956         case active:
3957                 if (mddev->pers) {
3958                         restart_array(mddev);
3959                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3960                         wake_up(&mddev->sb_wait);
3961                         err = 0;
3962                 } else {
3963                         mddev->ro = 0;
3964                         set_disk_ro(mddev->gendisk, 0);
3965                         err = do_md_run(mddev);
3966                 }
3967                 break;
3968         case write_pending:
3969         case active_idle:
3970                 /* these cannot be set */
3971                 break;
3972         }
3973         if (err)
3974                 return err;
3975         else {
3976                 if (mddev->hold_active == UNTIL_IOCTL)
3977                         mddev->hold_active = 0;
3978                 sysfs_notify_dirent_safe(mddev->sysfs_state);
3979                 return len;
3980         }
3981 }
3982 static struct md_sysfs_entry md_array_state =
3983 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3984
3985 static ssize_t
3986 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
3987         return sprintf(page, "%d\n",
3988                        atomic_read(&mddev->max_corr_read_errors));
3989 }
3990
3991 static ssize_t
3992 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
3993 {
3994         char *e;
3995         unsigned long n = simple_strtoul(buf, &e, 10);
3996
3997         if (*buf && (*e == 0 || *e == '\n')) {
3998                 atomic_set(&mddev->max_corr_read_errors, n);
3999                 return len;
4000         }
4001         return -EINVAL;
4002 }
4003
4004 static struct md_sysfs_entry max_corr_read_errors =
4005 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
4006         max_corrected_read_errors_store);
4007
4008 static ssize_t
4009 null_show(struct mddev *mddev, char *page)
4010 {
4011         return -EINVAL;
4012 }
4013
4014 static ssize_t
4015 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
4016 {
4017         /* buf must be %d:%d\n? giving major and minor numbers */
4018         /* The new device is added to the array.
4019          * If the array has a persistent superblock, we read the
4020          * superblock to initialise info and check validity.
4021          * Otherwise, only checking done is that in bind_rdev_to_array,
4022          * which mainly checks size.
4023          */
4024         char *e;
4025         int major = simple_strtoul(buf, &e, 10);
4026         int minor;
4027         dev_t dev;
4028         struct md_rdev *rdev;
4029         int err;
4030
4031         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4032                 return -EINVAL;
4033         minor = simple_strtoul(e+1, &e, 10);
4034         if (*e && *e != '\n')
4035                 return -EINVAL;
4036         dev = MKDEV(major, minor);
4037         if (major != MAJOR(dev) ||
4038             minor != MINOR(dev))
4039                 return -EOVERFLOW;
4040
4041
4042         if (mddev->persistent) {
4043                 rdev = md_import_device(dev, mddev->major_version,
4044                                         mddev->minor_version);
4045                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4046                         struct md_rdev *rdev0
4047                                 = list_entry(mddev->disks.next,
4048                                              struct md_rdev, same_set);
4049                         err = super_types[mddev->major_version]
4050                                 .load_super(rdev, rdev0, mddev->minor_version);
4051                         if (err < 0)
4052                                 goto out;
4053                 }
4054         } else if (mddev->external)
4055                 rdev = md_import_device(dev, -2, -1);
4056         else
4057                 rdev = md_import_device(dev, -1, -1);
4058
4059         if (IS_ERR(rdev))
4060                 return PTR_ERR(rdev);
4061         err = bind_rdev_to_array(rdev, mddev);
4062  out:
4063         if (err)
4064                 export_rdev(rdev);
4065         return err ? err : len;
4066 }
4067
4068 static struct md_sysfs_entry md_new_device =
4069 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4070
4071 static ssize_t
4072 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4073 {
4074         char *end;
4075         unsigned long chunk, end_chunk;
4076
4077         if (!mddev->bitmap)
4078                 goto out;
4079         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4080         while (*buf) {
4081                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4082                 if (buf == end) break;
4083                 if (*end == '-') { /* range */
4084                         buf = end + 1;
4085                         end_chunk = simple_strtoul(buf, &end, 0);
4086                         if (buf == end) break;
4087                 }
4088                 if (*end && !isspace(*end)) break;
4089                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4090                 buf = skip_spaces(end);
4091         }
4092         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4093 out:
4094         return len;
4095 }
4096
4097 static struct md_sysfs_entry md_bitmap =
4098 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4099
4100 static ssize_t
4101 size_show(struct mddev *mddev, char *page)
4102 {
4103         return sprintf(page, "%llu\n",
4104                 (unsigned long long)mddev->dev_sectors / 2);
4105 }
4106
4107 static int update_size(struct mddev *mddev, sector_t num_sectors);
4108
4109 static ssize_t
4110 size_store(struct mddev *mddev, const char *buf, size_t len)
4111 {
4112         /* If array is inactive, we can reduce the component size, but
4113          * not increase it (except from 0).
4114          * If array is active, we can try an on-line resize
4115          */
4116         sector_t sectors;
4117         int err = strict_blocks_to_sectors(buf, &sectors);
4118
4119         if (err < 0)
4120                 return err;
4121         if (mddev->pers) {
4122                 err = update_size(mddev, sectors);
4123                 md_update_sb(mddev, 1);
4124         } else {
4125                 if (mddev->dev_sectors == 0 ||
4126                     mddev->dev_sectors > sectors)
4127                         mddev->dev_sectors = sectors;
4128                 else
4129                         err = -ENOSPC;
4130         }
4131         return err ? err : len;
4132 }
4133
4134 static struct md_sysfs_entry md_size =
4135 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4136
4137
4138 /* Metadata version.
4139  * This is one of
4140  *   'none' for arrays with no metadata (good luck...)
4141  *   'external' for arrays with externally managed metadata,
4142  * or N.M for internally known formats
4143  */
4144 static ssize_t
4145 metadata_show(struct mddev *mddev, char *page)
4146 {
4147         if (mddev->persistent)
4148                 return sprintf(page, "%d.%d\n",
4149                                mddev->major_version, mddev->minor_version);
4150         else if (mddev->external)
4151                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4152         else
4153                 return sprintf(page, "none\n");
4154 }
4155
4156 static ssize_t
4157 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4158 {
4159         int major, minor;
4160         char *e;
4161         /* Changing the details of 'external' metadata is
4162          * always permitted.  Otherwise there must be
4163          * no devices attached to the array.
4164          */
4165         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4166                 ;
4167         else if (!list_empty(&mddev->disks))
4168                 return -EBUSY;
4169
4170         if (cmd_match(buf, "none")) {
4171                 mddev->persistent = 0;
4172                 mddev->external = 0;
4173                 mddev->major_version = 0;
4174                 mddev->minor_version = 90;
4175                 return len;
4176         }
4177         if (strncmp(buf, "external:", 9) == 0) {
4178                 size_t namelen = len-9;
4179                 if (namelen >= sizeof(mddev->metadata_type))
4180                         namelen = sizeof(mddev->metadata_type)-1;
4181                 strncpy(mddev->metadata_type, buf+9, namelen);
4182                 mddev->metadata_type[namelen] = 0;
4183                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4184                         mddev->metadata_type[--namelen] = 0;
4185                 mddev->persistent = 0;
4186                 mddev->external = 1;
4187                 mddev->major_version = 0;
4188                 mddev->minor_version = 90;
4189                 return len;
4190         }
4191         major = simple_strtoul(buf, &e, 10);
4192         if (e==buf || *e != '.')
4193                 return -EINVAL;
4194         buf = e+1;
4195         minor = simple_strtoul(buf, &e, 10);
4196         if (e==buf || (*e && *e != '\n') )
4197                 return -EINVAL;
4198         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4199                 return -ENOENT;
4200         mddev->major_version = major;
4201         mddev->minor_version = minor;
4202         mddev->persistent = 1;
4203         mddev->external = 0;
4204         return len;
4205 }
4206
4207 static struct md_sysfs_entry md_metadata =
4208 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4209
4210 static ssize_t
4211 action_show(struct mddev *mddev, char *page)
4212 {
4213         char *type = "idle";
4214         if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4215                 type = "frozen";
4216         else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4217             (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4218                 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4219                         type = "reshape";
4220                 else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4221                         if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4222                                 type = "resync";
4223                         else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4224                                 type = "check";
4225                         else
4226                                 type = "repair";
4227                 } else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4228                         type = "recover";
4229         }
4230         return sprintf(page, "%s\n", type);
4231 }
4232
4233 static void reap_sync_thread(struct mddev *mddev);
4234
4235 static ssize_t
4236 action_store(struct mddev *mddev, const char *page, size_t len)
4237 {
4238         if (!mddev->pers || !mddev->pers->sync_request)
4239                 return -EINVAL;
4240
4241         if (cmd_match(page, "frozen"))
4242                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4243         else
4244                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4245
4246         if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4247                 if (mddev->sync_thread) {
4248                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4249                         reap_sync_thread(mddev);
4250                 }
4251         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4252                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4253                 return -EBUSY;
4254         else if (cmd_match(page, "resync"))
4255                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4256         else if (cmd_match(page, "recover")) {
4257                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4258                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4259         } else if (cmd_match(page, "reshape")) {
4260                 int err;
4261                 if (mddev->pers->start_reshape == NULL)
4262                         return -EINVAL;
4263                 err = mddev->pers->start_reshape(mddev);
4264                 if (err)
4265                         return err;
4266                 sysfs_notify(&mddev->kobj, NULL, "degraded");
4267         } else {
4268                 if (cmd_match(page, "check"))
4269                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4270                 else if (!cmd_match(page, "repair"))
4271                         return -EINVAL;
4272                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4273                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4274         }
4275         if (mddev->ro == 2) {
4276                 /* A write to sync_action is enough to justify
4277                  * canceling read-auto mode
4278                  */
4279                 mddev->ro = 0;
4280                 md_wakeup_thread(mddev->sync_thread);
4281         }
4282         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4283         md_wakeup_thread(mddev->thread);
4284         sysfs_notify_dirent_safe(mddev->sysfs_action);
4285         return len;
4286 }
4287
4288 static ssize_t
4289 mismatch_cnt_show(struct mddev *mddev, char *page)
4290 {
4291         return sprintf(page, "%llu\n",
4292                        (unsigned long long)
4293                        atomic64_read(&mddev->resync_mismatches));
4294 }
4295
4296 static struct md_sysfs_entry md_scan_mode =
4297 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4298
4299
4300 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4301
4302 static ssize_t
4303 sync_min_show(struct mddev *mddev, char *page)
4304 {
4305         return sprintf(page, "%d (%s)\n", speed_min(mddev),
4306                        mddev->sync_speed_min ? "local": "system");
4307 }
4308
4309 static ssize_t
4310 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4311 {
4312         int min;
4313         char *e;
4314         if (strncmp(buf, "system", 6)==0) {
4315                 mddev->sync_speed_min = 0;
4316                 return len;
4317         }
4318         min = simple_strtoul(buf, &e, 10);
4319         if (buf == e || (*e && *e != '\n') || min <= 0)
4320                 return -EINVAL;
4321         mddev->sync_speed_min = min;
4322         return len;
4323 }
4324
4325 static struct md_sysfs_entry md_sync_min =
4326 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4327
4328 static ssize_t
4329 sync_max_show(struct mddev *mddev, char *page)
4330 {
4331         return sprintf(page, "%d (%s)\n", speed_max(mddev),
4332                        mddev->sync_speed_max ? "local": "system");
4333 }
4334
4335 static ssize_t
4336 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4337 {
4338         int max;
4339         char *e;
4340         if (strncmp(buf, "system", 6)==0) {
4341                 mddev->sync_speed_max = 0;
4342                 return len;
4343         }
4344         max = simple_strtoul(buf, &e, 10);
4345         if (buf == e || (*e && *e != '\n') || max <= 0)
4346                 return -EINVAL;
4347         mddev->sync_speed_max = max;
4348         return len;
4349 }
4350
4351 static struct md_sysfs_entry md_sync_max =
4352 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4353
4354 static ssize_t
4355 degraded_show(struct mddev *mddev, char *page)
4356 {
4357         return sprintf(page, "%d\n", mddev->degraded);
4358 }
4359 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4360
4361 static ssize_t
4362 sync_force_parallel_show(struct mddev *mddev, char *page)
4363 {
4364         return sprintf(page, "%d\n", mddev->parallel_resync);
4365 }
4366
4367 static ssize_t
4368 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4369 {
4370         long n;
4371
4372         if (strict_strtol(buf, 10, &n))
4373                 return -EINVAL;
4374
4375         if (n != 0 && n != 1)
4376                 return -EINVAL;
4377
4378         mddev->parallel_resync = n;
4379
4380         if (mddev->sync_thread)
4381                 wake_up(&resync_wait);
4382
4383         return len;
4384 }
4385
4386 /* force parallel resync, even with shared block devices */
4387 static struct md_sysfs_entry md_sync_force_parallel =
4388 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4389        sync_force_parallel_show, sync_force_parallel_store);
4390
4391 static ssize_t
4392 sync_speed_show(struct mddev *mddev, char *page)
4393 {
4394         unsigned long resync, dt, db;
4395         if (mddev->curr_resync == 0)
4396                 return sprintf(page, "none\n");
4397         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4398         dt = (jiffies - mddev->resync_mark) / HZ;
4399         if (!dt) dt++;
4400         db = resync - mddev->resync_mark_cnt;
4401         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4402 }
4403
4404 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4405
4406 static ssize_t
4407 sync_completed_show(struct mddev *mddev, char *page)
4408 {
4409         unsigned long long max_sectors, resync;
4410
4411         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4412                 return sprintf(page, "none\n");
4413
4414         if (mddev->curr_resync == 1 ||
4415             mddev->curr_resync == 2)
4416                 return sprintf(page, "delayed\n");
4417
4418         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4419             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4420                 max_sectors = mddev->resync_max_sectors;
4421         else
4422                 max_sectors = mddev->dev_sectors;
4423
4424         resync = mddev->curr_resync_completed;
4425         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4426 }
4427
4428 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4429
4430 static ssize_t
4431 min_sync_show(struct mddev *mddev, char *page)
4432 {
4433         return sprintf(page, "%llu\n",
4434                        (unsigned long long)mddev->resync_min);
4435 }
4436 static ssize_t
4437 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4438 {
4439         unsigned long long min;
4440         if (strict_strtoull(buf, 10, &min))
4441                 return -EINVAL;
4442         if (min > mddev->resync_max)
4443                 return -EINVAL;
4444         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4445                 return -EBUSY;
4446
4447         /* Must be a multiple of chunk_size */
4448         if (mddev->chunk_sectors) {
4449                 sector_t temp = min;
4450                 if (sector_div(temp, mddev->chunk_sectors))
4451                         return -EINVAL;
4452         }
4453         mddev->resync_min = min;
4454
4455         return len;
4456 }
4457
4458 static struct md_sysfs_entry md_min_sync =
4459 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4460
4461 static ssize_t
4462 max_sync_show(struct mddev *mddev, char *page)
4463 {
4464         if (mddev->resync_max == MaxSector)
4465                 return sprintf(page, "max\n");
4466         else
4467                 return sprintf(page, "%llu\n",
4468                                (unsigned long long)mddev->resync_max);
4469 }
4470 static ssize_t
4471 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4472 {
4473         if (strncmp(buf, "max", 3) == 0)
4474                 mddev->resync_max = MaxSector;
4475         else {
4476                 unsigned long long max;
4477                 if (strict_strtoull(buf, 10, &max))
4478                         return -EINVAL;
4479                 if (max < mddev->resync_min)
4480                         return -EINVAL;
4481                 if (max < mddev->resync_max &&
4482                     mddev->ro == 0 &&
4483                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4484                         return -EBUSY;
4485
4486                 /* Must be a multiple of chunk_size */
4487                 if (mddev->chunk_sectors) {
4488                         sector_t temp = max;
4489                         if (sector_div(temp, mddev->chunk_sectors))
4490                                 return -EINVAL;
4491                 }
4492                 mddev->resync_max = max;
4493         }
4494         wake_up(&mddev->recovery_wait);
4495         return len;
4496 }
4497
4498 static struct md_sysfs_entry md_max_sync =
4499 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4500
4501 static ssize_t
4502 suspend_lo_show(struct mddev *mddev, char *page)
4503 {
4504         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4505 }
4506
4507 static ssize_t
4508 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4509 {
4510         char *e;
4511         unsigned long long new = simple_strtoull(buf, &e, 10);
4512         unsigned long long old = mddev->suspend_lo;
4513
4514         if (mddev->pers == NULL || 
4515             mddev->pers->quiesce == NULL)
4516                 return -EINVAL;
4517         if (buf == e || (*e && *e != '\n'))
4518                 return -EINVAL;
4519
4520         mddev->suspend_lo = new;
4521         if (new >= old)
4522                 /* Shrinking suspended region */
4523                 mddev->pers->quiesce(mddev, 2);
4524         else {
4525                 /* Expanding suspended region - need to wait */
4526                 mddev->pers->quiesce(mddev, 1);
4527                 mddev->pers->quiesce(mddev, 0);
4528         }
4529         return len;
4530 }
4531 static struct md_sysfs_entry md_suspend_lo =
4532 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4533
4534
4535 static ssize_t
4536 suspend_hi_show(struct mddev *mddev, char *page)
4537 {
4538         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4539 }
4540
4541 static ssize_t
4542 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4543 {
4544         char *e;
4545         unsigned long long new = simple_strtoull(buf, &e, 10);
4546         unsigned long long old = mddev->suspend_hi;
4547
4548         if (mddev->pers == NULL ||
4549             mddev->pers->quiesce == NULL)
4550                 return -EINVAL;
4551         if (buf == e || (*e && *e != '\n'))
4552                 return -EINVAL;
4553
4554         mddev->suspend_hi = new;
4555         if (new <= old)
4556                 /* Shrinking suspended region */
4557                 mddev->pers->quiesce(mddev, 2);
4558         else {
4559                 /* Expanding suspended region - need to wait */
4560                 mddev->pers->quiesce(mddev, 1);
4561                 mddev->pers->quiesce(mddev, 0);
4562         }
4563         return len;
4564 }
4565 static struct md_sysfs_entry md_suspend_hi =
4566 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4567
4568 static ssize_t
4569 reshape_position_show(struct mddev *mddev, char *page)
4570 {
4571         if (mddev->reshape_position != MaxSector)
4572                 return sprintf(page, "%llu\n",
4573                                (unsigned long long)mddev->reshape_position);
4574         strcpy(page, "none\n");
4575         return 5;
4576 }
4577
4578 static ssize_t
4579 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4580 {
4581         struct md_rdev *rdev;
4582         char *e;
4583         unsigned long long new = simple_strtoull(buf, &e, 10);
4584         if (mddev->pers)
4585                 return -EBUSY;
4586         if (buf == e || (*e && *e != '\n'))
4587                 return -EINVAL;
4588         mddev->reshape_position = new;
4589         mddev->delta_disks = 0;
4590         mddev->reshape_backwards = 0;
4591         mddev->new_level = mddev->level;
4592         mddev->new_layout = mddev->layout;
4593         mddev->new_chunk_sectors = mddev->chunk_sectors;
4594         rdev_for_each(rdev, mddev)
4595                 rdev->new_data_offset = rdev->data_offset;
4596         return len;
4597 }
4598
4599 static struct md_sysfs_entry md_reshape_position =
4600 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4601        reshape_position_store);
4602
4603 static ssize_t
4604 reshape_direction_show(struct mddev *mddev, char *page)
4605 {
4606         return sprintf(page, "%s\n",
4607                        mddev->reshape_backwards ? "backwards" : "forwards");
4608 }
4609
4610 static ssize_t
4611 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4612 {
4613         int backwards = 0;
4614         if (cmd_match(buf, "forwards"))
4615                 backwards = 0;
4616         else if (cmd_match(buf, "backwards"))
4617                 backwards = 1;
4618         else
4619                 return -EINVAL;
4620         if (mddev->reshape_backwards == backwards)
4621                 return len;
4622
4623         /* check if we are allowed to change */
4624         if (mddev->delta_disks)
4625                 return -EBUSY;
4626
4627         if (mddev->persistent &&
4628             mddev->major_version == 0)
4629                 return -EINVAL;
4630
4631         mddev->reshape_backwards = backwards;
4632         return len;
4633 }
4634
4635 static struct md_sysfs_entry md_reshape_direction =
4636 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4637        reshape_direction_store);
4638
4639 static ssize_t
4640 array_size_show(struct mddev *mddev, char *page)
4641 {
4642         if (mddev->external_size)
4643                 return sprintf(page, "%llu\n",
4644                                (unsigned long long)mddev->array_sectors/2);
4645         else
4646                 return sprintf(page, "default\n");
4647 }
4648
4649 static ssize_t
4650 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4651 {
4652         sector_t sectors;
4653
4654         if (strncmp(buf, "default", 7) == 0) {
4655                 if (mddev->pers)
4656                         sectors = mddev->pers->size(mddev, 0, 0);
4657                 else
4658                         sectors = mddev->array_sectors;
4659
4660                 mddev->external_size = 0;
4661         } else {
4662                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
4663                         return -EINVAL;
4664                 if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4665                         return -E2BIG;
4666
4667                 mddev->external_size = 1;
4668         }
4669
4670         mddev->array_sectors = sectors;
4671         if (mddev->pers) {
4672                 set_capacity(mddev->gendisk, mddev->array_sectors);
4673                 revalidate_disk(mddev->gendisk);
4674         }
4675         return len;
4676 }
4677
4678 static struct md_sysfs_entry md_array_size =
4679 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4680        array_size_store);
4681
4682 static struct attribute *md_default_attrs[] = {
4683         &md_level.attr,
4684         &md_layout.attr,
4685         &md_raid_disks.attr,
4686         &md_chunk_size.attr,
4687         &md_size.attr,
4688         &md_resync_start.attr,
4689         &md_metadata.attr,
4690         &md_new_device.attr,
4691         &md_safe_delay.attr,
4692         &md_array_state.attr,
4693         &md_reshape_position.attr,
4694         &md_reshape_direction.attr,
4695         &md_array_size.attr,
4696         &max_corr_read_errors.attr,
4697         NULL,
4698 };
4699
4700 static struct attribute *md_redundancy_attrs[] = {
4701         &md_scan_mode.attr,
4702         &md_mismatches.attr,
4703         &md_sync_min.attr,
4704         &md_sync_max.attr,
4705         &md_sync_speed.attr,
4706         &md_sync_force_parallel.attr,
4707         &md_sync_completed.attr,
4708         &md_min_sync.attr,
4709         &md_max_sync.attr,
4710         &md_suspend_lo.attr,
4711         &md_suspend_hi.attr,
4712         &md_bitmap.attr,
4713         &md_degraded.attr,
4714         NULL,
4715 };
4716 static struct attribute_group md_redundancy_group = {
4717         .name = NULL,
4718         .attrs = md_redundancy_attrs,
4719 };
4720
4721
4722 static ssize_t
4723 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4724 {
4725         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4726         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4727         ssize_t rv;
4728
4729         if (!entry->show)
4730                 return -EIO;
4731         spin_lock(&all_mddevs_lock);
4732         if (list_empty(&mddev->all_mddevs)) {
4733                 spin_unlock(&all_mddevs_lock);
4734                 return -EBUSY;
4735         }
4736         mddev_get(mddev);
4737         spin_unlock(&all_mddevs_lock);
4738
4739         rv = mddev_lock(mddev);
4740         if (!rv) {
4741                 rv = entry->show(mddev, page);
4742                 mddev_unlock(mddev);
4743         }
4744         mddev_put(mddev);
4745         return rv;
4746 }
4747
4748 static ssize_t
4749 md_attr_store(struct kobject *kobj, struct attribute *attr,
4750               const char *page, size_t length)
4751 {
4752         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4753         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4754         ssize_t rv;
4755
4756         if (!entry->store)
4757                 return -EIO;
4758         if (!capable(CAP_SYS_ADMIN))
4759                 return -EACCES;
4760         spin_lock(&all_mddevs_lock);
4761         if (list_empty(&mddev->all_mddevs)) {
4762                 spin_unlock(&all_mddevs_lock);
4763                 return -EBUSY;
4764         }
4765         mddev_get(mddev);
4766         spin_unlock(&all_mddevs_lock);
4767         if (entry->store == new_dev_store)
4768                 flush_workqueue(md_misc_wq);
4769         rv = mddev_lock(mddev);
4770         if (!rv) {
4771                 rv = entry->store(mddev, page, length);
4772                 mddev_unlock(mddev);
4773         }
4774         mddev_put(mddev);
4775         return rv;
4776 }
4777
4778 static void md_free(struct kobject *ko)
4779 {
4780         struct mddev *mddev = container_of(ko, struct mddev, kobj);
4781
4782         if (mddev->sysfs_state)
4783                 sysfs_put(mddev->sysfs_state);
4784
4785         if (mddev->gendisk) {
4786                 del_gendisk(mddev->gendisk);
4787                 put_disk(mddev->gendisk);
4788         }
4789         if (mddev->queue)
4790                 blk_cleanup_queue(mddev->queue);
4791
4792         kfree(mddev);
4793 }
4794
4795 static const struct sysfs_ops md_sysfs_ops = {
4796         .show   = md_attr_show,
4797         .store  = md_attr_store,
4798 };
4799 static struct kobj_type md_ktype = {
4800         .release        = md_free,
4801         .sysfs_ops      = &md_sysfs_ops,
4802         .default_attrs  = md_default_attrs,
4803 };
4804
4805 int mdp_major = 0;
4806
4807 static void mddev_delayed_delete(struct work_struct *ws)
4808 {
4809         struct mddev *mddev = container_of(ws, struct mddev, del_work);
4810
4811         sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4812         kobject_del(&mddev->kobj);
4813         kobject_put(&mddev->kobj);
4814 }
4815
4816 static int md_alloc(dev_t dev, char *name)
4817 {
4818         static DEFINE_MUTEX(disks_mutex);
4819         struct mddev *mddev = mddev_find(dev);
4820         struct gendisk *disk;
4821         int partitioned;
4822         int shift;
4823         int unit;
4824         int error;
4825
4826         if (!mddev)
4827                 return -ENODEV;
4828
4829         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4830         shift = partitioned ? MdpMinorShift : 0;
4831         unit = MINOR(mddev->unit) >> shift;
4832
4833         /* wait for any previous instance of this device to be
4834          * completely removed (mddev_delayed_delete).
4835          */
4836         flush_workqueue(md_misc_wq);
4837
4838         mutex_lock(&disks_mutex);
4839         error = -EEXIST;
4840         if (mddev->gendisk)
4841                 goto abort;
4842
4843         if (name) {
4844                 /* Need to ensure that 'name' is not a duplicate.
4845                  */
4846                 struct mddev *mddev2;
4847                 spin_lock(&all_mddevs_lock);
4848
4849                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4850                         if (mddev2->gendisk &&
4851                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
4852                                 spin_unlock(&all_mddevs_lock);
4853                                 goto abort;
4854                         }
4855                 spin_unlock(&all_mddevs_lock);
4856         }
4857
4858         error = -ENOMEM;
4859         mddev->queue = blk_alloc_queue(GFP_KERNEL);
4860         if (!mddev->queue)
4861                 goto abort;
4862         mddev->queue->queuedata = mddev;
4863
4864         blk_queue_make_request(mddev->queue, md_make_request);
4865         blk_set_stacking_limits(&mddev->queue->limits);
4866
4867         disk = alloc_disk(1 << shift);
4868         if (!disk) {
4869                 blk_cleanup_queue(mddev->queue);
4870                 mddev->queue = NULL;
4871                 goto abort;
4872         }
4873         disk->major = MAJOR(mddev->unit);
4874         disk->first_minor = unit << shift;
4875         if (name)
4876                 strcpy(disk->disk_name, name);
4877         else if (partitioned)
4878                 sprintf(disk->disk_name, "md_d%d", unit);
4879         else
4880                 sprintf(disk->disk_name, "md%d", unit);
4881         disk->fops = &md_fops;
4882         disk->private_data = mddev;
4883         disk->queue = mddev->queue;
4884         blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4885         /* Allow extended partitions.  This makes the
4886          * 'mdp' device redundant, but we can't really
4887          * remove it now.
4888          */
4889         disk->flags |= GENHD_FL_EXT_DEVT;
4890         mddev->gendisk = disk;
4891         /* As soon as we call add_disk(), another thread could get
4892          * through to md_open, so make sure it doesn't get too far
4893          */
4894         mutex_lock(&mddev->open_mutex);
4895         add_disk(disk);
4896
4897         error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4898                                      &disk_to_dev(disk)->kobj, "%s", "md");
4899         if (error) {
4900                 /* This isn't possible, but as kobject_init_and_add is marked
4901                  * __must_check, we must do something with the result
4902                  */
4903                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4904                        disk->disk_name);
4905                 error = 0;
4906         }
4907         if (mddev->kobj.sd &&
4908             sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4909                 printk(KERN_DEBUG "pointless warning\n");
4910         mutex_unlock(&mddev->open_mutex);
4911  abort:
4912         mutex_unlock(&disks_mutex);
4913         if (!error && mddev->kobj.sd) {
4914                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
4915                 mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4916         }
4917         mddev_put(mddev);
4918         return error;
4919 }
4920
4921 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4922 {
4923         md_alloc(dev, NULL);
4924         return NULL;
4925 }
4926
4927 static int add_named_array(const char *val, struct kernel_param *kp)
4928 {
4929         /* val must be "md_*" where * is not all digits.
4930          * We allocate an array with a large free minor number, and
4931          * set the name to val.  val must not already be an active name.
4932          */
4933         int len = strlen(val);
4934         char buf[DISK_NAME_LEN];
4935
4936         while (len && val[len-1] == '\n')
4937                 len--;
4938         if (len >= DISK_NAME_LEN)
4939                 return -E2BIG;
4940         strlcpy(buf, val, len+1);
4941         if (strncmp(buf, "md_", 3) != 0)
4942                 return -EINVAL;
4943         return md_alloc(0, buf);
4944 }
4945
4946 static void md_safemode_timeout(unsigned long data)
4947 {
4948         struct mddev *mddev = (struct mddev *) data;
4949
4950         if (!atomic_read(&mddev->writes_pending)) {
4951                 mddev->safemode = 1;
4952                 if (mddev->external)
4953                         sysfs_notify_dirent_safe(mddev->sysfs_state);
4954         }
4955         md_wakeup_thread(mddev->thread);
4956 }
4957
4958 static int start_dirty_degraded;
4959
4960 int md_run(struct mddev *mddev)
4961 {
4962         int err;
4963         struct md_rdev *rdev;
4964         struct md_personality *pers;
4965
4966         if (list_empty(&mddev->disks))
4967                 /* cannot run an array with no devices.. */
4968                 return -EINVAL;
4969
4970         if (mddev->pers)
4971                 return -EBUSY;
4972         /* Cannot run until previous stop completes properly */
4973         if (mddev->sysfs_active)
4974                 return -EBUSY;
4975
4976         /*
4977          * Analyze all RAID superblock(s)
4978          */
4979         if (!mddev->raid_disks) {
4980                 if (!mddev->persistent)
4981                         return -EINVAL;
4982                 analyze_sbs(mddev);
4983         }
4984
4985         if (mddev->level != LEVEL_NONE)
4986                 request_module("md-level-%d", mddev->level);
4987         else if (mddev->clevel[0])
4988                 request_module("md-%s", mddev->clevel);
4989
4990         /*
4991          * Drop all container device buffers, from now on
4992          * the only valid external interface is through the md
4993          * device.
4994          */
4995         rdev_for_each(rdev, mddev) {
4996                 if (test_bit(Faulty, &rdev->flags))
4997                         continue;
4998                 sync_blockdev(rdev->bdev);
4999                 invalidate_bdev(rdev->bdev);
5000
5001                 /* perform some consistency tests on the device.
5002                  * We don't want the data to overlap the metadata,
5003                  * Internal Bitmap issues have been handled elsewhere.
5004                  */
5005                 if (rdev->meta_bdev) {
5006                         /* Nothing to check */;
5007                 } else if (rdev->data_offset < rdev->sb_start) {
5008                         if (mddev->dev_sectors &&
5009                             rdev->data_offset + mddev->dev_sectors
5010                             > rdev->sb_start) {
5011                                 printk("md: %s: data overlaps metadata\n",
5012                                        mdname(mddev));
5013                                 return -EINVAL;
5014                         }
5015                 } else {
5016                         if (rdev->sb_start + rdev->sb_size/512
5017                             > rdev->data_offset) {
5018                                 printk("md: %s: metadata overlaps data\n",
5019                                        mdname(mddev));
5020                                 return -EINVAL;
5021                         }
5022                 }
5023                 sysfs_notify_dirent_safe(rdev->sysfs_state);
5024         }
5025
5026         if (mddev->bio_set == NULL)
5027                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
5028
5029         spin_lock(&pers_lock);
5030         pers = find_pers(mddev->level, mddev->clevel);
5031         if (!pers || !try_module_get(pers->owner)) {
5032                 spin_unlock(&pers_lock);
5033                 if (mddev->level != LEVEL_NONE)
5034                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5035                                mddev->level);
5036                 else
5037                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5038                                mddev->clevel);
5039                 return -EINVAL;
5040         }
5041         mddev->pers = pers;
5042         spin_unlock(&pers_lock);
5043         if (mddev->level != pers->level) {
5044                 mddev->level = pers->level;
5045                 mddev->new_level = pers->level;
5046         }
5047         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5048
5049         if (mddev->reshape_position != MaxSector &&
5050             pers->start_reshape == NULL) {
5051                 /* This personality cannot handle reshaping... */
5052                 mddev->pers = NULL;
5053                 module_put(pers->owner);
5054                 return -EINVAL;
5055         }
5056
5057         if (pers->sync_request) {
5058                 /* Warn if this is a potentially silly
5059                  * configuration.
5060                  */
5061                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5062                 struct md_rdev *rdev2;
5063                 int warned = 0;
5064
5065                 rdev_for_each(rdev, mddev)
5066                         rdev_for_each(rdev2, mddev) {
5067                                 if (rdev < rdev2 &&
5068                                     rdev->bdev->bd_contains ==
5069                                     rdev2->bdev->bd_contains) {
5070                                         printk(KERN_WARNING
5071                                                "%s: WARNING: %s appears to be"
5072                                                " on the same physical disk as"
5073                                                " %s.\n",
5074                                                mdname(mddev),
5075                                                bdevname(rdev->bdev,b),
5076                                                bdevname(rdev2->bdev,b2));
5077                                         warned = 1;
5078                                 }
5079                         }
5080
5081                 if (warned)
5082                         printk(KERN_WARNING
5083                                "True protection against single-disk"
5084                                " failure might be compromised.\n");
5085         }
5086
5087         mddev->recovery = 0;
5088         /* may be over-ridden by personality */
5089         mddev->resync_max_sectors = mddev->dev_sectors;
5090
5091         mddev->ok_start_degraded = start_dirty_degraded;
5092
5093         if (start_readonly && mddev->ro == 0)
5094                 mddev->ro = 2; /* read-only, but switch on first write */
5095
5096         err = mddev->pers->run(mddev);
5097         if (err)
5098                 printk(KERN_ERR "md: pers->run() failed ...\n");
5099         else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
5100                 WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5101                           " but 'external_size' not in effect?\n", __func__);
5102                 printk(KERN_ERR
5103                        "md: invalid array_size %llu > default size %llu\n",
5104                        (unsigned long long)mddev->array_sectors / 2,
5105                        (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
5106                 err = -EINVAL;
5107                 mddev->pers->stop(mddev);
5108         }
5109         if (err == 0 && mddev->pers->sync_request &&
5110             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5111                 err = bitmap_create(mddev);
5112                 if (err) {
5113                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5114                                mdname(mddev), err);
5115                         mddev->pers->stop(mddev);
5116                 }
5117         }
5118         if (err) {
5119                 module_put(mddev->pers->owner);
5120                 mddev->pers = NULL;
5121                 bitmap_destroy(mddev);
5122                 return err;
5123         }
5124         if (mddev->pers->sync_request) {
5125                 if (mddev->kobj.sd &&
5126                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5127                         printk(KERN_WARNING
5128                                "md: cannot register extra attributes for %s\n",
5129                                mdname(mddev));
5130                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5131         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
5132                 mddev->ro = 0;
5133
5134         atomic_set(&mddev->writes_pending,0);
5135         atomic_set(&mddev->max_corr_read_errors,
5136                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5137         mddev->safemode = 0;
5138         mddev->safemode_timer.function = md_safemode_timeout;
5139         mddev->safemode_timer.data = (unsigned long) mddev;
5140         mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5141         mddev->in_sync = 1;
5142         smp_wmb();
5143         mddev->ready = 1;
5144         rdev_for_each(rdev, mddev)
5145                 if (rdev->raid_disk >= 0)
5146                         if (sysfs_link_rdev(mddev, rdev))
5147                                 /* failure here is OK */;
5148         
5149         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5150         
5151         if (mddev->flags)
5152                 md_update_sb(mddev, 0);
5153
5154         md_new_event(mddev);
5155         sysfs_notify_dirent_safe(mddev->sysfs_state);
5156         sysfs_notify_dirent_safe(mddev->sysfs_action);
5157         sysfs_notify(&mddev->kobj, NULL, "degraded");
5158         return 0;
5159 }
5160 EXPORT_SYMBOL_GPL(md_run);
5161
5162 static int do_md_run(struct mddev *mddev)
5163 {
5164         int err;
5165
5166         err = md_run(mddev);
5167         if (err)
5168                 goto out;
5169         err = bitmap_load(mddev);
5170         if (err) {
5171                 bitmap_destroy(mddev);
5172                 goto out;
5173         }
5174
5175         md_wakeup_thread(mddev->thread);
5176         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5177
5178         set_capacity(mddev->gendisk, mddev->array_sectors);
5179         revalidate_disk(mddev->gendisk);
5180         mddev->changed = 1;
5181         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5182 out:
5183         return err;
5184 }
5185
5186 static int restart_array(struct mddev *mddev)
5187 {
5188         struct gendisk *disk = mddev->gendisk;
5189
5190         /* Complain if it has no devices */
5191         if (list_empty(&mddev->disks))
5192                 return -ENXIO;
5193         if (!mddev->pers)
5194                 return -EINVAL;
5195         if (!mddev->ro)
5196                 return -EBUSY;
5197         mddev->safemode = 0;
5198         mddev->ro = 0;
5199         set_disk_ro(disk, 0);
5200         printk(KERN_INFO "md: %s switched to read-write mode.\n",
5201                 mdname(mddev));
5202         /* Kick recovery or resync if necessary */
5203         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5204         md_wakeup_thread(mddev->thread);
5205         md_wakeup_thread(mddev->sync_thread);
5206         sysfs_notify_dirent_safe(mddev->sysfs_state);
5207         return 0;
5208 }
5209
5210 /* similar to deny_write_access, but accounts for our holding a reference
5211  * to the file ourselves */
5212 static int deny_bitmap_write_access(struct file * file)
5213 {
5214         struct inode *inode = file->f_mapping->host;
5215
5216         spin_lock(&inode->i_lock);
5217         if (atomic_read(&inode->i_writecount) > 1) {
5218                 spin_unlock(&inode->i_lock);
5219                 return -ETXTBSY;
5220         }
5221         atomic_set(&inode->i_writecount, -1);
5222         spin_unlock(&inode->i_lock);
5223
5224         return 0;
5225 }
5226
5227 void restore_bitmap_write_access(struct file *file)
5228 {
5229         struct inode *inode = file->f_mapping->host;
5230
5231         spin_lock(&inode->i_lock);
5232         atomic_set(&inode->i_writecount, 1);
5233         spin_unlock(&inode->i_lock);
5234 }
5235
5236 static void md_clean(struct mddev *mddev)
5237 {
5238         mddev->array_sectors = 0;
5239         mddev->external_size = 0;
5240         mddev->dev_sectors = 0;
5241         mddev->raid_disks = 0;
5242         mddev->recovery_cp = 0;
5243         mddev->resync_min = 0;
5244         mddev->resync_max = MaxSector;
5245         mddev->reshape_position = MaxSector;
5246         mddev->external = 0;
5247         mddev->persistent = 0;
5248         mddev->level = LEVEL_NONE;
5249         mddev->clevel[0] = 0;
5250         mddev->flags = 0;
5251         mddev->ro = 0;
5252         mddev->metadata_type[0] = 0;
5253         mddev->chunk_sectors = 0;
5254         mddev->ctime = mddev->utime = 0;
5255         mddev->layout = 0;
5256         mddev->max_disks = 0;
5257         mddev->events = 0;
5258         mddev->can_decrease_events = 0;
5259         mddev->delta_disks = 0;
5260         mddev->reshape_backwards = 0;
5261         mddev->new_level = LEVEL_NONE;
5262         mddev->new_layout = 0;
5263         mddev->new_chunk_sectors = 0;
5264         mddev->curr_resync = 0;
5265         atomic64_set(&mddev->resync_mismatches, 0);
5266         mddev->suspend_lo = mddev->suspend_hi = 0;
5267         mddev->sync_speed_min = mddev->sync_speed_max = 0;
5268         mddev->recovery = 0;
5269         mddev->in_sync = 0;
5270         mddev->changed = 0;
5271         mddev->degraded = 0;
5272         mddev->safemode = 0;
5273         mddev->merge_check_needed = 0;
5274         mddev->bitmap_info.offset = 0;
5275         mddev->bitmap_info.default_offset = 0;
5276         mddev->bitmap_info.default_space = 0;
5277         mddev->bitmap_info.chunksize = 0;
5278         mddev->bitmap_info.daemon_sleep = 0;
5279         mddev->bitmap_info.max_write_behind = 0;
5280 }
5281
5282 static void __md_stop_writes(struct mddev *mddev)
5283 {
5284         if (mddev->sync_thread) {
5285                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5286                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5287                 reap_sync_thread(mddev);
5288         }
5289
5290         del_timer_sync(&mddev->safemode_timer);
5291
5292         bitmap_flush(mddev);
5293         md_super_wait(mddev);
5294
5295         if (!mddev->in_sync || mddev->flags) {
5296                 /* mark array as shutdown cleanly */
5297                 mddev->in_sync = 1;
5298                 md_update_sb(mddev, 1);
5299         }
5300 }
5301
5302 void md_stop_writes(struct mddev *mddev)
5303 {
5304         mddev_lock(mddev);
5305         __md_stop_writes(mddev);
5306         mddev_unlock(mddev);
5307 }
5308 EXPORT_SYMBOL_GPL(md_stop_writes);
5309
5310 static void __md_stop(struct mddev *mddev)
5311 {
5312         mddev->ready = 0;
5313         mddev->pers->stop(mddev);
5314         if (mddev->pers->sync_request && mddev->to_remove == NULL)
5315                 mddev->to_remove = &md_redundancy_group;
5316         module_put(mddev->pers->owner);
5317         mddev->pers = NULL;
5318         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5319 }
5320
5321 void md_stop(struct mddev *mddev)
5322 {
5323         /* stop the array and free an attached data structures.
5324          * This is called from dm-raid
5325          */
5326         __md_stop(mddev);
5327         bitmap_destroy(mddev);
5328         if (mddev->bio_set)
5329                 bioset_free(mddev->bio_set);
5330 }
5331
5332 EXPORT_SYMBOL_GPL(md_stop);
5333
5334 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5335 {
5336         int err = 0;
5337         mutex_lock(&mddev->open_mutex);
5338         if (atomic_read(&mddev->openers) > !!bdev) {
5339                 printk("md: %s still in use.\n",mdname(mddev));
5340                 err = -EBUSY;
5341                 goto out;
5342         }
5343         if (bdev)
5344                 sync_blockdev(bdev);
5345         if (mddev->pers) {
5346                 __md_stop_writes(mddev);
5347
5348                 err  = -ENXIO;
5349                 if (mddev->ro==1)
5350                         goto out;
5351                 mddev->ro = 1;
5352                 set_disk_ro(mddev->gendisk, 1);
5353                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5354                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5355                 err = 0;        
5356         }
5357 out:
5358         mutex_unlock(&mddev->open_mutex);
5359         return err;
5360 }
5361
5362 /* mode:
5363  *   0 - completely stop and dis-assemble array
5364  *   2 - stop but do not disassemble array
5365  */
5366 static int do_md_stop(struct mddev * mddev, int mode,
5367                       struct block_device *bdev)
5368 {
5369         struct gendisk *disk = mddev->gendisk;
5370         struct md_rdev *rdev;
5371
5372         mutex_lock(&mddev->open_mutex);
5373         if (atomic_read(&mddev->openers) > !!bdev ||
5374             mddev->sysfs_active) {
5375                 printk("md: %s still in use.\n",mdname(mddev));
5376                 mutex_unlock(&mddev->open_mutex);
5377                 return -EBUSY;
5378         }
5379         if (bdev)
5380                 /* It is possible IO was issued on some other
5381                  * open file which was closed before we took ->open_mutex.
5382                  * As that was not the last close __blkdev_put will not
5383                  * have called sync_blockdev, so we must.
5384                  */
5385                 sync_blockdev(bdev);
5386
5387         if (mddev->pers) {
5388                 if (mddev->ro)
5389                         set_disk_ro(disk, 0);
5390
5391                 __md_stop_writes(mddev);
5392                 __md_stop(mddev);
5393                 mddev->queue->merge_bvec_fn = NULL;
5394                 mddev->queue->backing_dev_info.congested_fn = NULL;
5395
5396                 /* tell userspace to handle 'inactive' */
5397                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5398
5399                 rdev_for_each(rdev, mddev)
5400                         if (rdev->raid_disk >= 0)
5401                                 sysfs_unlink_rdev(mddev, rdev);
5402
5403                 set_capacity(disk, 0);
5404                 mutex_unlock(&mddev->open_mutex);
5405                 mddev->changed = 1;
5406                 revalidate_disk(disk);
5407
5408                 if (mddev->ro)
5409                         mddev->ro = 0;
5410         } else
5411                 mutex_unlock(&mddev->open_mutex);
5412         /*
5413          * Free resources if final stop
5414          */
5415         if (mode == 0) {
5416                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5417
5418                 bitmap_destroy(mddev);
5419                 if (mddev->bitmap_info.file) {
5420                         restore_bitmap_write_access(mddev->bitmap_info.file);
5421                         fput(mddev->bitmap_info.file);
5422                         mddev->bitmap_info.file = NULL;
5423                 }
5424                 mddev->bitmap_info.offset = 0;
5425
5426                 export_array(mddev);
5427
5428                 md_clean(mddev);
5429                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5430                 if (mddev->hold_active == UNTIL_STOP)
5431                         mddev->hold_active = 0;
5432         }
5433         blk_integrity_unregister(disk);
5434         md_new_event(mddev);
5435         sysfs_notify_dirent_safe(mddev->sysfs_state);
5436         return 0;
5437 }
5438
5439 #ifndef MODULE
5440 static void autorun_array(struct mddev *mddev)
5441 {
5442         struct md_rdev *rdev;
5443         int err;
5444
5445         if (list_empty(&mddev->disks))
5446                 return;
5447
5448         printk(KERN_INFO "md: running: ");
5449
5450         rdev_for_each(rdev, mddev) {
5451                 char b[BDEVNAME_SIZE];
5452                 printk("<%s>", bdevname(rdev->bdev,b));
5453         }
5454         printk("\n");
5455
5456         err = do_md_run(mddev);
5457         if (err) {
5458                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5459                 do_md_stop(mddev, 0, NULL);
5460         }
5461 }
5462
5463 /*
5464  * lets try to run arrays based on all disks that have arrived
5465  * until now. (those are in pending_raid_disks)
5466  *
5467  * the method: pick the first pending disk, collect all disks with
5468  * the same UUID, remove all from the pending list and put them into
5469  * the 'same_array' list. Then order this list based on superblock
5470  * update time (freshest comes first), kick out 'old' disks and
5471  * compare superblocks. If everything's fine then run it.
5472  *
5473  * If "unit" is allocated, then bump its reference count
5474  */
5475 static void autorun_devices(int part)
5476 {
5477         struct md_rdev *rdev0, *rdev, *tmp;
5478         struct mddev *mddev;
5479         char b[BDEVNAME_SIZE];
5480
5481         printk(KERN_INFO "md: autorun ...\n");
5482         while (!list_empty(&pending_raid_disks)) {
5483                 int unit;
5484                 dev_t dev;
5485                 LIST_HEAD(candidates);
5486                 rdev0 = list_entry(pending_raid_disks.next,
5487                                          struct md_rdev, same_set);
5488
5489                 printk(KERN_INFO "md: considering %s ...\n",
5490                         bdevname(rdev0->bdev,b));
5491                 INIT_LIST_HEAD(&candidates);
5492                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5493                         if (super_90_load(rdev, rdev0, 0) >= 0) {
5494                                 printk(KERN_INFO "md:  adding %s ...\n",
5495                                         bdevname(rdev->bdev,b));
5496                                 list_move(&rdev->same_set, &candidates);
5497                         }
5498                 /*
5499                  * now we have a set of devices, with all of them having
5500                  * mostly sane superblocks. It's time to allocate the
5501                  * mddev.
5502                  */
5503                 if (part) {
5504                         dev = MKDEV(mdp_major,
5505                                     rdev0->preferred_minor << MdpMinorShift);
5506                         unit = MINOR(dev) >> MdpMinorShift;
5507                 } else {
5508                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5509                         unit = MINOR(dev);
5510                 }
5511                 if (rdev0->preferred_minor != unit) {
5512                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5513                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5514                         break;
5515                 }
5516
5517                 md_probe(dev, NULL, NULL);
5518                 mddev = mddev_find(dev);
5519                 if (!mddev || !mddev->gendisk) {
5520                         if (mddev)
5521                                 mddev_put(mddev);
5522                         printk(KERN_ERR
5523                                 "md: cannot allocate memory for md drive.\n");
5524                         break;
5525                 }
5526                 if (mddev_lock(mddev)) 
5527                         printk(KERN_WARNING "md: %s locked, cannot run\n",
5528                                mdname(mddev));
5529                 else if (mddev->raid_disks || mddev->major_version
5530                          || !list_empty(&mddev->disks)) {
5531                         printk(KERN_WARNING 
5532                                 "md: %s already running, cannot run %s\n",
5533                                 mdname(mddev), bdevname(rdev0->bdev,b));
5534                         mddev_unlock(mddev);
5535                 } else {
5536                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
5537                         mddev->persistent = 1;
5538                         rdev_for_each_list(rdev, tmp, &candidates) {
5539                                 list_del_init(&rdev->same_set);
5540                                 if (bind_rdev_to_array(rdev, mddev))
5541                                         export_rdev(rdev);
5542                         }
5543                         autorun_array(mddev);
5544                         mddev_unlock(mddev);
5545                 }
5546                 /* on success, candidates will be empty, on error
5547                  * it won't...
5548                  */
5549                 rdev_for_each_list(rdev, tmp, &candidates) {
5550                         list_del_init(&rdev->same_set);
5551                         export_rdev(rdev);
5552                 }
5553                 mddev_put(mddev);
5554         }
5555         printk(KERN_INFO "md: ... autorun DONE.\n");
5556 }
5557 #endif /* !MODULE */
5558
5559 static int get_version(void __user * arg)
5560 {
5561         mdu_version_t ver;
5562
5563         ver.major = MD_MAJOR_VERSION;
5564         ver.minor = MD_MINOR_VERSION;
5565         ver.patchlevel = MD_PATCHLEVEL_VERSION;
5566
5567         if (copy_to_user(arg, &ver, sizeof(ver)))
5568                 return -EFAULT;
5569
5570         return 0;
5571 }
5572
5573 static int get_array_info(struct mddev * mddev, void __user * arg)
5574 {
5575         mdu_array_info_t info;
5576         int nr,working,insync,failed,spare;
5577         struct md_rdev *rdev;
5578
5579         nr = working = insync = failed = spare = 0;
5580         rcu_read_lock();
5581         rdev_for_each_rcu(rdev, mddev) {
5582                 nr++;
5583                 if (test_bit(Faulty, &rdev->flags))
5584                         failed++;
5585                 else {
5586                         working++;
5587                         if (test_bit(In_sync, &rdev->flags))
5588                                 insync++;       
5589                         else
5590                                 spare++;
5591                 }
5592         }
5593         rcu_read_unlock();
5594
5595         info.major_version = mddev->major_version;
5596         info.minor_version = mddev->minor_version;
5597         info.patch_version = MD_PATCHLEVEL_VERSION;
5598         info.ctime         = mddev->ctime;
5599         info.level         = mddev->level;
5600         info.size          = mddev->dev_sectors / 2;
5601         if (info.size != mddev->dev_sectors / 2) /* overflow */
5602                 info.size = -1;
5603         info.nr_disks      = nr;
5604         info.raid_disks    = mddev->raid_disks;
5605         info.md_minor      = mddev->md_minor;
5606         info.not_persistent= !mddev->persistent;
5607
5608         info.utime         = mddev->utime;
5609         info.state         = 0;
5610         if (mddev->in_sync)
5611                 info.state = (1<<MD_SB_CLEAN);
5612         if (mddev->bitmap && mddev->bitmap_info.offset)
5613                 info.state = (1<<MD_SB_BITMAP_PRESENT);
5614         info.active_disks  = insync;
5615         info.working_disks = working;
5616         info.failed_disks  = failed;
5617         info.spare_disks   = spare;
5618
5619         info.layout        = mddev->layout;
5620         info.chunk_size    = mddev->chunk_sectors << 9;
5621
5622         if (copy_to_user(arg, &info, sizeof(info)))
5623                 return -EFAULT;
5624
5625         return 0;
5626 }
5627
5628 static int get_bitmap_file(struct mddev * mddev, void __user * arg)
5629 {
5630         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5631         char *ptr, *buf = NULL;
5632         int err = -ENOMEM;
5633
5634         if (md_allow_write(mddev))
5635                 file = kmalloc(sizeof(*file), GFP_NOIO);
5636         else
5637                 file = kmalloc(sizeof(*file), GFP_KERNEL);
5638
5639         if (!file)
5640                 goto out;
5641
5642         /* bitmap disabled, zero the first byte and copy out */
5643         if (!mddev->bitmap || !mddev->bitmap->storage.file) {
5644                 file->pathname[0] = '\0';
5645                 goto copy_out;
5646         }
5647
5648         buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5649         if (!buf)
5650                 goto out;
5651
5652         ptr = d_path(&mddev->bitmap->storage.file->f_path,
5653                      buf, sizeof(file->pathname));
5654         if (IS_ERR(ptr))
5655                 goto out;
5656
5657         strcpy(file->pathname, ptr);
5658
5659 copy_out:
5660         err = 0;
5661         if (copy_to_user(arg, file, sizeof(*file)))
5662                 err = -EFAULT;
5663 out:
5664         kfree(buf);
5665         kfree(file);
5666         return err;
5667 }
5668
5669 static int get_disk_info(struct mddev * mddev, void __user * arg)
5670 {
5671         mdu_disk_info_t info;
5672         struct md_rdev *rdev;
5673
5674         if (copy_from_user(&info, arg, sizeof(info)))
5675                 return -EFAULT;
5676
5677         rcu_read_lock();
5678         rdev = find_rdev_nr_rcu(mddev, info.number);
5679         if (rdev) {
5680                 info.major = MAJOR(rdev->bdev->bd_dev);
5681                 info.minor = MINOR(rdev->bdev->bd_dev);
5682                 info.raid_disk = rdev->raid_disk;
5683                 info.state = 0;
5684                 if (test_bit(Faulty, &rdev->flags))
5685                         info.state |= (1<<MD_DISK_FAULTY);
5686                 else if (test_bit(In_sync, &rdev->flags)) {
5687                         info.state |= (1<<MD_DISK_ACTIVE);
5688                         info.state |= (1<<MD_DISK_SYNC);
5689                 }
5690                 if (test_bit(WriteMostly, &rdev->flags))
5691                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
5692         } else {
5693                 info.major = info.minor = 0;
5694                 info.raid_disk = -1;
5695                 info.state = (1<<MD_DISK_REMOVED);
5696         }
5697         rcu_read_unlock();
5698
5699         if (copy_to_user(arg, &info, sizeof(info)))
5700                 return -EFAULT;
5701
5702         return 0;
5703 }
5704
5705 static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info)
5706 {
5707         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5708         struct md_rdev *rdev;
5709         dev_t dev = MKDEV(info->major,info->minor);
5710
5711         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5712                 return -EOVERFLOW;
5713
5714         if (!mddev->raid_disks) {
5715                 int err;
5716                 /* expecting a device which has a superblock */
5717                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5718                 if (IS_ERR(rdev)) {
5719                         printk(KERN_WARNING 
5720                                 "md: md_import_device returned %ld\n",
5721                                 PTR_ERR(rdev));
5722                         return PTR_ERR(rdev);
5723                 }
5724                 if (!list_empty(&mddev->disks)) {
5725                         struct md_rdev *rdev0
5726                                 = list_entry(mddev->disks.next,
5727                                              struct md_rdev, same_set);
5728                         err = super_types[mddev->major_version]
5729                                 .load_super(rdev, rdev0, mddev->minor_version);
5730                         if (err < 0) {
5731                                 printk(KERN_WARNING 
5732                                         "md: %s has different UUID to %s\n",
5733                                         bdevname(rdev->bdev,b), 
5734                                         bdevname(rdev0->bdev,b2));
5735                                 export_rdev(rdev);
5736                                 return -EINVAL;
5737                         }
5738                 }
5739                 err = bind_rdev_to_array(rdev, mddev);
5740                 if (err)
5741                         export_rdev(rdev);
5742                 return err;
5743         }
5744
5745         /*
5746          * add_new_disk can be used once the array is assembled
5747          * to add "hot spares".  They must already have a superblock
5748          * written
5749          */
5750         if (mddev->pers) {
5751                 int err;
5752                 if (!mddev->pers->hot_add_disk) {
5753                         printk(KERN_WARNING 
5754                                 "%s: personality does not support diskops!\n",
5755                                mdname(mddev));
5756                         return -EINVAL;
5757                 }
5758                 if (mddev->persistent)
5759                         rdev = md_import_device(dev, mddev->major_version,
5760                                                 mddev->minor_version);
5761                 else
5762                         rdev = md_import_device(dev, -1, -1);
5763                 if (IS_ERR(rdev)) {
5764                         printk(KERN_WARNING 
5765                                 "md: md_import_device returned %ld\n",
5766                                 PTR_ERR(rdev));
5767                         return PTR_ERR(rdev);
5768                 }
5769                 /* set saved_raid_disk if appropriate */
5770                 if (!mddev->persistent) {
5771                         if (info->state & (1<<MD_DISK_SYNC)  &&
5772                             info->raid_disk < mddev->raid_disks) {
5773                                 rdev->raid_disk = info->raid_disk;
5774                                 set_bit(In_sync, &rdev->flags);
5775                         } else
5776                                 rdev->raid_disk = -1;
5777                 } else
5778                         super_types[mddev->major_version].
5779                                 validate_super(mddev, rdev);
5780                 if ((info->state & (1<<MD_DISK_SYNC)) &&
5781                      rdev->raid_disk != info->raid_disk) {
5782                         /* This was a hot-add request, but events doesn't
5783                          * match, so reject it.
5784                          */
5785                         export_rdev(rdev);
5786                         return -EINVAL;
5787                 }
5788
5789                 if (test_bit(In_sync, &rdev->flags))
5790                         rdev->saved_raid_disk = rdev->raid_disk;
5791                 else
5792                         rdev->saved_raid_disk = -1;
5793
5794                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
5795                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5796                         set_bit(WriteMostly, &rdev->flags);
5797                 else
5798                         clear_bit(WriteMostly, &rdev->flags);
5799
5800                 rdev->raid_disk = -1;
5801                 err = bind_rdev_to_array(rdev, mddev);
5802                 if (!err && !mddev->pers->hot_remove_disk) {
5803                         /* If there is hot_add_disk but no hot_remove_disk
5804                          * then added disks for geometry changes,
5805                          * and should be added immediately.
5806                          */
5807                         super_types[mddev->major_version].
5808                                 validate_super(mddev, rdev);
5809                         err = mddev->pers->hot_add_disk(mddev, rdev);
5810                         if (err)
5811                                 unbind_rdev_from_array(rdev);
5812                 }
5813                 if (err)
5814                         export_rdev(rdev);
5815                 else
5816                         sysfs_notify_dirent_safe(rdev->sysfs_state);
5817
5818                 md_update_sb(mddev, 1);
5819                 if (mddev->degraded)
5820                         set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5821                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5822                 if (!err)
5823                         md_new_event(mddev);
5824                 md_wakeup_thread(mddev->thread);
5825                 return err;
5826         }
5827
5828         /* otherwise, add_new_disk is only allowed
5829          * for major_version==0 superblocks
5830          */
5831         if (mddev->major_version != 0) {
5832                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5833                        mdname(mddev));
5834                 return -EINVAL;
5835         }
5836
5837         if (!(info->state & (1<<MD_DISK_FAULTY))) {
5838                 int err;
5839                 rdev = md_import_device(dev, -1, 0);
5840                 if (IS_ERR(rdev)) {
5841                         printk(KERN_WARNING 
5842                                 "md: error, md_import_device() returned %ld\n",
5843                                 PTR_ERR(rdev));
5844                         return PTR_ERR(rdev);
5845                 }
5846                 rdev->desc_nr = info->number;
5847                 if (info->raid_disk < mddev->raid_disks)
5848                         rdev->raid_disk = info->raid_disk;
5849                 else
5850                         rdev->raid_disk = -1;
5851
5852                 if (rdev->raid_disk < mddev->raid_disks)
5853                         if (info->state & (1<<MD_DISK_SYNC))
5854                                 set_bit(In_sync, &rdev->flags);
5855
5856                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5857                         set_bit(WriteMostly, &rdev->flags);
5858
5859                 if (!mddev->persistent) {
5860                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
5861                         rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5862                 } else
5863                         rdev->sb_start = calc_dev_sboffset(rdev);
5864                 rdev->sectors = rdev->sb_start;
5865
5866                 err = bind_rdev_to_array(rdev, mddev);
5867                 if (err) {
5868                         export_rdev(rdev);
5869                         return err;
5870                 }
5871         }
5872
5873         return 0;
5874 }
5875
5876 static int hot_remove_disk(struct mddev * mddev, dev_t dev)
5877 {
5878         char b[BDEVNAME_SIZE];
5879         struct md_rdev *rdev;
5880
5881         rdev = find_rdev(mddev, dev);
5882         if (!rdev)
5883                 return -ENXIO;
5884
5885         if (rdev->raid_disk >= 0)
5886                 goto busy;
5887
5888         kick_rdev_from_array(rdev);
5889         md_update_sb(mddev, 1);
5890         md_new_event(mddev);
5891
5892         return 0;
5893 busy:
5894         printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5895                 bdevname(rdev->bdev,b), mdname(mddev));
5896         return -EBUSY;
5897 }
5898
5899 static int hot_add_disk(struct mddev * mddev, dev_t dev)
5900 {
5901         char b[BDEVNAME_SIZE];
5902         int err;
5903         struct md_rdev *rdev;
5904
5905         if (!mddev->pers)
5906                 return -ENODEV;
5907
5908         if (mddev->major_version != 0) {
5909                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5910                         " version-0 superblocks.\n",
5911                         mdname(mddev));
5912                 return -EINVAL;
5913         }
5914         if (!mddev->pers->hot_add_disk) {
5915                 printk(KERN_WARNING 
5916                         "%s: personality does not support diskops!\n",
5917                         mdname(mddev));
5918                 return -EINVAL;
5919         }
5920
5921         rdev = md_import_device(dev, -1, 0);
5922         if (IS_ERR(rdev)) {
5923                 printk(KERN_WARNING 
5924                         "md: error, md_import_device() returned %ld\n",
5925                         PTR_ERR(rdev));
5926                 return -EINVAL;
5927         }
5928
5929         if (mddev->persistent)
5930                 rdev->sb_start = calc_dev_sboffset(rdev);
5931         else
5932                 rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5933
5934         rdev->sectors = rdev->sb_start;
5935
5936         if (test_bit(Faulty, &rdev->flags)) {
5937                 printk(KERN_WARNING 
5938                         "md: can not hot-add faulty %s disk to %s!\n",
5939                         bdevname(rdev->bdev,b), mdname(mddev));
5940                 err = -EINVAL;
5941                 goto abort_export;
5942         }
5943         clear_bit(In_sync, &rdev->flags);
5944         rdev->desc_nr = -1;
5945         rdev->saved_raid_disk = -1;
5946         err = bind_rdev_to_array(rdev, mddev);
5947         if (err)
5948                 goto abort_export;
5949
5950         /*
5951          * The rest should better be atomic, we can have disk failures
5952          * noticed in interrupt contexts ...
5953          */
5954
5955         rdev->raid_disk = -1;
5956
5957         md_update_sb(mddev, 1);
5958
5959         /*
5960          * Kick recovery, maybe this spare has to be added to the
5961          * array immediately.
5962          */
5963         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5964         md_wakeup_thread(mddev->thread);
5965         md_new_event(mddev);
5966         return 0;
5967
5968 abort_export:
5969         export_rdev(rdev);
5970         return err;
5971 }
5972
5973 static int set_bitmap_file(struct mddev *mddev, int fd)
5974 {
5975         int err;
5976
5977         if (mddev->pers) {
5978                 if (!mddev->pers->quiesce)
5979                         return -EBUSY;
5980                 if (mddev->recovery || mddev->sync_thread)
5981                         return -EBUSY;
5982                 /* we should be able to change the bitmap.. */
5983         }
5984
5985
5986         if (fd >= 0) {
5987                 if (mddev->bitmap)
5988                         return -EEXIST; /* cannot add when bitmap is present */
5989                 mddev->bitmap_info.file = fget(fd);
5990
5991                 if (mddev->bitmap_info.file == NULL) {
5992                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5993                                mdname(mddev));
5994                         return -EBADF;
5995                 }
5996
5997                 err = deny_bitmap_write_access(mddev->bitmap_info.file);
5998                 if (err) {
5999                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
6000                                mdname(mddev));
6001                         fput(mddev->bitmap_info.file);
6002                         mddev->bitmap_info.file = NULL;
6003                         return err;
6004                 }
6005                 mddev->bitmap_info.offset = 0; /* file overrides offset */
6006         } else if (mddev->bitmap == NULL)
6007                 return -ENOENT; /* cannot remove what isn't there */
6008         err = 0;
6009         if (mddev->pers) {
6010                 mddev->pers->quiesce(mddev, 1);
6011                 if (fd >= 0) {
6012                         err = bitmap_create(mddev);
6013                         if (!err)
6014                                 err = bitmap_load(mddev);
6015                 }
6016                 if (fd < 0 || err) {
6017                         bitmap_destroy(mddev);
6018                         fd = -1; /* make sure to put the file */
6019                 }
6020                 mddev->pers->quiesce(mddev, 0);
6021         }
6022         if (fd < 0) {
6023                 if (mddev->bitmap_info.file) {
6024                         restore_bitmap_write_access(mddev->bitmap_info.file);
6025                         fput(mddev->bitmap_info.file);
6026                 }
6027                 mddev->bitmap_info.file = NULL;
6028         }
6029
6030         return err;
6031 }
6032
6033 /*
6034  * set_array_info is used two different ways
6035  * The original usage is when creating a new array.
6036  * In this usage, raid_disks is > 0 and it together with
6037  *  level, size, not_persistent,layout,chunksize determine the
6038  *  shape of the array.
6039  *  This will always create an array with a type-0.90.0 superblock.
6040  * The newer usage is when assembling an array.
6041  *  In this case raid_disks will be 0, and the major_version field is
6042  *  use to determine which style super-blocks are to be found on the devices.
6043  *  The minor and patch _version numbers are also kept incase the
6044  *  super_block handler wishes to interpret them.
6045  */
6046 static int set_array_info(struct mddev * mddev, mdu_array_info_t *info)
6047 {
6048
6049         if (info->raid_disks == 0) {
6050                 /* just setting version number for superblock loading */
6051                 if (info->major_version < 0 ||
6052                     info->major_version >= ARRAY_SIZE(super_types) ||
6053                     super_types[info->major_version].name == NULL) {
6054                         /* maybe try to auto-load a module? */
6055                         printk(KERN_INFO 
6056                                 "md: superblock version %d not known\n",
6057                                 info->major_version);
6058                         return -EINVAL;
6059                 }
6060                 mddev->major_version = info->major_version;
6061                 mddev->minor_version = info->minor_version;
6062                 mddev->patch_version = info->patch_version;
6063                 mddev->persistent = !info->not_persistent;
6064                 /* ensure mddev_put doesn't delete this now that there
6065                  * is some minimal configuration.
6066                  */
6067                 mddev->ctime         = get_seconds();
6068                 return 0;
6069         }
6070         mddev->major_version = MD_MAJOR_VERSION;
6071         mddev->minor_version = MD_MINOR_VERSION;
6072         mddev->patch_version = MD_PATCHLEVEL_VERSION;
6073         mddev->ctime         = get_seconds();
6074
6075         mddev->level         = info->level;
6076         mddev->clevel[0]     = 0;
6077         mddev->dev_sectors   = 2 * (sector_t)info->size;
6078         mddev->raid_disks    = info->raid_disks;
6079         /* don't set md_minor, it is determined by which /dev/md* was
6080          * openned
6081          */
6082         if (info->state & (1<<MD_SB_CLEAN))
6083                 mddev->recovery_cp = MaxSector;
6084         else
6085                 mddev->recovery_cp = 0;
6086         mddev->persistent    = ! info->not_persistent;
6087         mddev->external      = 0;
6088
6089         mddev->layout        = info->layout;
6090         mddev->chunk_sectors = info->chunk_size >> 9;
6091
6092         mddev->max_disks     = MD_SB_DISKS;
6093
6094         if (mddev->persistent)
6095                 mddev->flags         = 0;
6096         set_bit(MD_CHANGE_DEVS, &mddev->flags);
6097
6098         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6099         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6100         mddev->bitmap_info.offset = 0;
6101
6102         mddev->reshape_position = MaxSector;
6103
6104         /*
6105          * Generate a 128 bit UUID
6106          */
6107         get_random_bytes(mddev->uuid, 16);
6108
6109         mddev->new_level = mddev->level;
6110         mddev->new_chunk_sectors = mddev->chunk_sectors;
6111         mddev->new_layout = mddev->layout;
6112         mddev->delta_disks = 0;
6113         mddev->reshape_backwards = 0;
6114
6115         return 0;
6116 }
6117
6118 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6119 {
6120         WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6121
6122         if (mddev->external_size)
6123                 return;
6124
6125         mddev->array_sectors = array_sectors;
6126 }
6127 EXPORT_SYMBOL(md_set_array_sectors);
6128
6129 static int update_size(struct mddev *mddev, sector_t num_sectors)
6130 {
6131         struct md_rdev *rdev;
6132         int rv;
6133         int fit = (num_sectors == 0);
6134
6135         if (mddev->pers->resize == NULL)
6136                 return -EINVAL;
6137         /* The "num_sectors" is the number of sectors of each device that
6138          * is used.  This can only make sense for arrays with redundancy.
6139          * linear and raid0 always use whatever space is available. We can only
6140          * consider changing this number if no resync or reconstruction is
6141          * happening, and if the new size is acceptable. It must fit before the
6142          * sb_start or, if that is <data_offset, it must fit before the size
6143          * of each device.  If num_sectors is zero, we find the largest size
6144          * that fits.
6145          */
6146         if (mddev->sync_thread)
6147                 return -EBUSY;
6148
6149         rdev_for_each(rdev, mddev) {
6150                 sector_t avail = rdev->sectors;
6151
6152                 if (fit && (num_sectors == 0 || num_sectors > avail))
6153                         num_sectors = avail;
6154                 if (avail < num_sectors)
6155                         return -ENOSPC;
6156         }
6157         rv = mddev->pers->resize(mddev, num_sectors);
6158         if (!rv)
6159                 revalidate_disk(mddev->gendisk);
6160         return rv;
6161 }
6162
6163 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6164 {
6165         int rv;
6166         struct md_rdev *rdev;
6167         /* change the number of raid disks */
6168         if (mddev->pers->check_reshape == NULL)
6169                 return -EINVAL;
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)
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 int md_ioctl(struct block_device *bdev, fmode_t mode,
6341                         unsigned int cmd, unsigned long arg)
6342 {
6343         int err = 0;
6344         void __user *argp = (void __user *)arg;
6345         struct mddev *mddev = NULL;
6346         int ro;
6347
6348         switch (cmd) {
6349         case RAID_VERSION:
6350         case GET_ARRAY_INFO:
6351         case GET_DISK_INFO:
6352                 break;
6353         default:
6354                 if (!capable(CAP_SYS_ADMIN))
6355                         return -EACCES;
6356         }
6357
6358         /*
6359          * Commands dealing with the RAID driver but not any
6360          * particular array:
6361          */
6362         switch (cmd) {
6363         case RAID_VERSION:
6364                 err = get_version(argp);
6365                 goto done;
6366
6367         case PRINT_RAID_DEBUG:
6368                 err = 0;
6369                 md_print_devices();
6370                 goto done;
6371
6372 #ifndef MODULE
6373         case RAID_AUTORUN:
6374                 err = 0;
6375                 autostart_arrays(arg);
6376                 goto done;
6377 #endif
6378         default:;
6379         }
6380
6381         /*
6382          * Commands creating/starting a new array:
6383          */
6384
6385         mddev = bdev->bd_disk->private_data;
6386
6387         if (!mddev) {
6388                 BUG();
6389                 goto abort;
6390         }
6391
6392         /* Some actions do not requires the mutex */
6393         switch (cmd) {
6394         case GET_ARRAY_INFO:
6395                 if (!mddev->raid_disks && !mddev->external)
6396                         err = -ENODEV;
6397                 else
6398                         err = get_array_info(mddev, argp);
6399                 goto abort;
6400
6401         case GET_DISK_INFO:
6402                 if (!mddev->raid_disks && !mddev->external)
6403                         err = -ENODEV;
6404                 else
6405                         err = get_disk_info(mddev, argp);
6406                 goto abort;
6407
6408         case SET_DISK_FAULTY:
6409                 err = set_disk_faulty(mddev, new_decode_dev(arg));
6410                 goto abort;
6411         }
6412
6413         if (cmd == ADD_NEW_DISK)
6414                 /* need to ensure md_delayed_delete() has completed */
6415                 flush_workqueue(md_misc_wq);
6416
6417         err = mddev_lock(mddev);
6418         if (err) {
6419                 printk(KERN_INFO 
6420                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
6421                         err, cmd);
6422                 goto abort;
6423         }
6424
6425         if (cmd == SET_ARRAY_INFO) {
6426                 mdu_array_info_t info;
6427                 if (!arg)
6428                         memset(&info, 0, sizeof(info));
6429                 else if (copy_from_user(&info, argp, sizeof(info))) {
6430                         err = -EFAULT;
6431                         goto abort_unlock;
6432                 }
6433                 if (mddev->pers) {
6434                         err = update_array_info(mddev, &info);
6435                         if (err) {
6436                                 printk(KERN_WARNING "md: couldn't update"
6437                                        " array info. %d\n", err);
6438                                 goto abort_unlock;
6439                         }
6440                         goto done_unlock;
6441                 }
6442                 if (!list_empty(&mddev->disks)) {
6443                         printk(KERN_WARNING
6444                                "md: array %s already has disks!\n",
6445                                mdname(mddev));
6446                         err = -EBUSY;
6447                         goto abort_unlock;
6448                 }
6449                 if (mddev->raid_disks) {
6450                         printk(KERN_WARNING
6451                                "md: array %s already initialised!\n",
6452                                mdname(mddev));
6453                         err = -EBUSY;
6454                         goto abort_unlock;
6455                 }
6456                 err = set_array_info(mddev, &info);
6457                 if (err) {
6458                         printk(KERN_WARNING "md: couldn't set"
6459                                " array info. %d\n", err);
6460                         goto abort_unlock;
6461                 }
6462                 goto done_unlock;
6463         }
6464
6465         /*
6466          * Commands querying/configuring an existing array:
6467          */
6468         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6469          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6470         if ((!mddev->raid_disks && !mddev->external)
6471             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6472             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6473             && cmd != GET_BITMAP_FILE) {
6474                 err = -ENODEV;
6475                 goto abort_unlock;
6476         }
6477
6478         /*
6479          * Commands even a read-only array can execute:
6480          */
6481         switch (cmd) {
6482         case GET_BITMAP_FILE:
6483                 err = get_bitmap_file(mddev, argp);
6484                 goto done_unlock;
6485
6486         case RESTART_ARRAY_RW:
6487                 err = restart_array(mddev);
6488                 goto done_unlock;
6489
6490         case STOP_ARRAY:
6491                 err = do_md_stop(mddev, 0, bdev);
6492                 goto done_unlock;
6493
6494         case STOP_ARRAY_RO:
6495                 err = md_set_readonly(mddev, bdev);
6496                 goto done_unlock;
6497
6498         case BLKROSET:
6499                 if (get_user(ro, (int __user *)(arg))) {
6500                         err = -EFAULT;
6501                         goto done_unlock;
6502                 }
6503                 err = -EINVAL;
6504
6505                 /* if the bdev is going readonly the value of mddev->ro
6506                  * does not matter, no writes are coming
6507                  */
6508                 if (ro)
6509                         goto done_unlock;
6510
6511                 /* are we are already prepared for writes? */
6512                 if (mddev->ro != 1)
6513                         goto done_unlock;
6514
6515                 /* transitioning to readauto need only happen for
6516                  * arrays that call md_write_start
6517                  */
6518                 if (mddev->pers) {
6519                         err = restart_array(mddev);
6520                         if (err == 0) {
6521                                 mddev->ro = 2;
6522                                 set_disk_ro(mddev->gendisk, 0);
6523                         }
6524                 }
6525                 goto done_unlock;
6526         }
6527
6528         /*
6529          * The remaining ioctls are changing the state of the
6530          * superblock, so we do not allow them on read-only arrays.
6531          * However non-MD ioctls (e.g. get-size) will still come through
6532          * here and hit the 'default' below, so only disallow
6533          * 'md' ioctls, and switch to rw mode if started auto-readonly.
6534          */
6535         if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6536                 if (mddev->ro == 2) {
6537                         mddev->ro = 0;
6538                         sysfs_notify_dirent_safe(mddev->sysfs_state);
6539                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6540                         /* mddev_unlock will wake thread */
6541                         /* If a device failed while we were read-only, we
6542                          * need to make sure the metadata is updated now.
6543                          */
6544                         if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
6545                                 mddev_unlock(mddev);
6546                                 wait_event(mddev->sb_wait,
6547                                            !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
6548                                            !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6549                                 mddev_lock(mddev);
6550                         }
6551                 } else {
6552                         err = -EROFS;
6553                         goto abort_unlock;
6554                 }
6555         }
6556
6557         switch (cmd) {
6558         case ADD_NEW_DISK:
6559         {
6560                 mdu_disk_info_t info;
6561                 if (copy_from_user(&info, argp, sizeof(info)))
6562                         err = -EFAULT;
6563                 else
6564                         err = add_new_disk(mddev, &info);
6565                 goto done_unlock;
6566         }
6567
6568         case HOT_REMOVE_DISK:
6569                 err = hot_remove_disk(mddev, new_decode_dev(arg));
6570                 goto done_unlock;
6571
6572         case HOT_ADD_DISK:
6573                 err = hot_add_disk(mddev, new_decode_dev(arg));
6574                 goto done_unlock;
6575
6576         case RUN_ARRAY:
6577                 err = do_md_run(mddev);
6578                 goto done_unlock;
6579
6580         case SET_BITMAP_FILE:
6581                 err = set_bitmap_file(mddev, (int)arg);
6582                 goto done_unlock;
6583
6584         default:
6585                 err = -EINVAL;
6586                 goto abort_unlock;
6587         }
6588
6589 done_unlock:
6590 abort_unlock:
6591         if (mddev->hold_active == UNTIL_IOCTL &&
6592             err != -EINVAL)
6593                 mddev->hold_active = 0;
6594         mddev_unlock(mddev);
6595
6596         return err;
6597 done:
6598         if (err)
6599                 MD_BUG();
6600 abort:
6601         return err;
6602 }
6603 #ifdef CONFIG_COMPAT
6604 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6605                     unsigned int cmd, unsigned long arg)
6606 {
6607         switch (cmd) {
6608         case HOT_REMOVE_DISK:
6609         case HOT_ADD_DISK:
6610         case SET_DISK_FAULTY:
6611         case SET_BITMAP_FILE:
6612                 /* These take in integer arg, do not convert */
6613                 break;
6614         default:
6615                 arg = (unsigned long)compat_ptr(arg);
6616                 break;
6617         }
6618
6619         return md_ioctl(bdev, mode, cmd, arg);
6620 }
6621 #endif /* CONFIG_COMPAT */
6622
6623 static int md_open(struct block_device *bdev, fmode_t mode)
6624 {
6625         /*
6626          * Succeed if we can lock the mddev, which confirms that
6627          * it isn't being stopped right now.
6628          */
6629         struct mddev *mddev = mddev_find(bdev->bd_dev);
6630         int err;
6631
6632         if (!mddev)
6633                 return -ENODEV;
6634
6635         if (mddev->gendisk != bdev->bd_disk) {
6636                 /* we are racing with mddev_put which is discarding this
6637                  * bd_disk.
6638                  */
6639                 mddev_put(mddev);
6640                 /* Wait until bdev->bd_disk is definitely gone */
6641                 flush_workqueue(md_misc_wq);
6642                 /* Then retry the open from the top */
6643                 return -ERESTARTSYS;
6644         }
6645         BUG_ON(mddev != bdev->bd_disk->private_data);
6646
6647         if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6648                 goto out;
6649
6650         err = 0;
6651         atomic_inc(&mddev->openers);
6652         mutex_unlock(&mddev->open_mutex);
6653
6654         check_disk_change(bdev);
6655  out:
6656         return err;
6657 }
6658
6659 static int md_release(struct gendisk *disk, fmode_t mode)
6660 {
6661         struct mddev *mddev = disk->private_data;
6662
6663         BUG_ON(!mddev);
6664         atomic_dec(&mddev->openers);
6665         mddev_put(mddev);
6666
6667         return 0;
6668 }
6669
6670 static int md_media_changed(struct gendisk *disk)
6671 {
6672         struct mddev *mddev = disk->private_data;
6673
6674         return mddev->changed;
6675 }
6676
6677 static int md_revalidate(struct gendisk *disk)
6678 {
6679         struct mddev *mddev = disk->private_data;
6680
6681         mddev->changed = 0;
6682         return 0;
6683 }
6684 static const struct block_device_operations md_fops =
6685 {
6686         .owner          = THIS_MODULE,
6687         .open           = md_open,
6688         .release        = md_release,
6689         .ioctl          = md_ioctl,
6690 #ifdef CONFIG_COMPAT
6691         .compat_ioctl   = md_compat_ioctl,
6692 #endif
6693         .getgeo         = md_getgeo,
6694         .media_changed  = md_media_changed,
6695         .revalidate_disk= md_revalidate,
6696 };
6697
6698 static int md_thread(void * arg)
6699 {
6700         struct md_thread *thread = arg;
6701
6702         /*
6703          * md_thread is a 'system-thread', it's priority should be very
6704          * high. We avoid resource deadlocks individually in each
6705          * raid personality. (RAID5 does preallocation) We also use RR and
6706          * the very same RT priority as kswapd, thus we will never get
6707          * into a priority inversion deadlock.
6708          *
6709          * we definitely have to have equal or higher priority than
6710          * bdflush, otherwise bdflush will deadlock if there are too
6711          * many dirty RAID5 blocks.
6712          */
6713
6714         allow_signal(SIGKILL);
6715         while (!kthread_should_stop()) {
6716
6717                 /* We need to wait INTERRUPTIBLE so that
6718                  * we don't add to the load-average.
6719                  * That means we need to be sure no signals are
6720                  * pending
6721                  */
6722                 if (signal_pending(current))
6723                         flush_signals(current);
6724
6725                 wait_event_interruptible_timeout
6726                         (thread->wqueue,
6727                          test_bit(THREAD_WAKEUP, &thread->flags)
6728                          || kthread_should_stop(),
6729                          thread->timeout);
6730
6731                 clear_bit(THREAD_WAKEUP, &thread->flags);
6732                 if (!kthread_should_stop())
6733                         thread->run(thread);
6734         }
6735
6736         return 0;
6737 }
6738
6739 void md_wakeup_thread(struct md_thread *thread)
6740 {
6741         if (thread) {
6742                 pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
6743                 set_bit(THREAD_WAKEUP, &thread->flags);
6744                 wake_up(&thread->wqueue);
6745         }
6746 }
6747
6748 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
6749                 struct mddev *mddev, const char *name)
6750 {
6751         struct md_thread *thread;
6752
6753         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
6754         if (!thread)
6755                 return NULL;
6756
6757         init_waitqueue_head(&thread->wqueue);
6758
6759         thread->run = run;
6760         thread->mddev = mddev;
6761         thread->timeout = MAX_SCHEDULE_TIMEOUT;
6762         thread->tsk = kthread_run(md_thread, thread,
6763                                   "%s_%s",
6764                                   mdname(thread->mddev),
6765                                   name);
6766         if (IS_ERR(thread->tsk)) {
6767                 kfree(thread);
6768                 return NULL;
6769         }
6770         return thread;
6771 }
6772
6773 void md_unregister_thread(struct md_thread **threadp)
6774 {
6775         struct md_thread *thread = *threadp;
6776         if (!thread)
6777                 return;
6778         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6779         /* Locking ensures that mddev_unlock does not wake_up a
6780          * non-existent thread
6781          */
6782         spin_lock(&pers_lock);
6783         *threadp = NULL;
6784         spin_unlock(&pers_lock);
6785
6786         kthread_stop(thread->tsk);
6787         kfree(thread);
6788 }
6789
6790 void md_error(struct mddev *mddev, struct md_rdev *rdev)
6791 {
6792         if (!mddev) {
6793                 MD_BUG();
6794                 return;
6795         }
6796
6797         if (!rdev || test_bit(Faulty, &rdev->flags))
6798                 return;
6799
6800         if (!mddev->pers || !mddev->pers->error_handler)
6801                 return;
6802         mddev->pers->error_handler(mddev,rdev);
6803         if (mddev->degraded)
6804                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6805         sysfs_notify_dirent_safe(rdev->sysfs_state);
6806         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6807         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6808         md_wakeup_thread(mddev->thread);
6809         if (mddev->event_work.func)
6810                 queue_work(md_misc_wq, &mddev->event_work);
6811         md_new_event_inintr(mddev);
6812 }
6813
6814 /* seq_file implementation /proc/mdstat */
6815
6816 static void status_unused(struct seq_file *seq)
6817 {
6818         int i = 0;
6819         struct md_rdev *rdev;
6820
6821         seq_printf(seq, "unused devices: ");
6822
6823         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6824                 char b[BDEVNAME_SIZE];
6825                 i++;
6826                 seq_printf(seq, "%s ",
6827                               bdevname(rdev->bdev,b));
6828         }
6829         if (!i)
6830                 seq_printf(seq, "<none>");
6831
6832         seq_printf(seq, "\n");
6833 }
6834
6835
6836 static void status_resync(struct seq_file *seq, struct mddev * mddev)
6837 {
6838         sector_t max_sectors, resync, res;
6839         unsigned long dt, db;
6840         sector_t rt;
6841         int scale;
6842         unsigned int per_milli;
6843
6844         if (mddev->curr_resync <= 3)
6845                 resync = 0;
6846         else
6847                 resync = mddev->curr_resync
6848                         - atomic_read(&mddev->recovery_active);
6849
6850         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
6851             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6852                 max_sectors = mddev->resync_max_sectors;
6853         else
6854                 max_sectors = mddev->dev_sectors;
6855
6856         /*
6857          * Should not happen.
6858          */
6859         if (!max_sectors) {
6860                 MD_BUG();
6861                 return;
6862         }
6863         /* Pick 'scale' such that (resync>>scale)*1000 will fit
6864          * in a sector_t, and (max_sectors>>scale) will fit in a
6865          * u32, as those are the requirements for sector_div.
6866          * Thus 'scale' must be at least 10
6867          */
6868         scale = 10;
6869         if (sizeof(sector_t) > sizeof(unsigned long)) {
6870                 while ( max_sectors/2 > (1ULL<<(scale+32)))
6871                         scale++;
6872         }
6873         res = (resync>>scale)*1000;
6874         sector_div(res, (u32)((max_sectors>>scale)+1));
6875
6876         per_milli = res;
6877         {
6878                 int i, x = per_milli/50, y = 20-x;
6879                 seq_printf(seq, "[");
6880                 for (i = 0; i < x; i++)
6881                         seq_printf(seq, "=");
6882                 seq_printf(seq, ">");
6883                 for (i = 0; i < y; i++)
6884                         seq_printf(seq, ".");
6885                 seq_printf(seq, "] ");
6886         }
6887         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6888                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6889                     "reshape" :
6890                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6891                      "check" :
6892                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6893                       "resync" : "recovery"))),
6894                    per_milli/10, per_milli % 10,
6895                    (unsigned long long) resync/2,
6896                    (unsigned long long) max_sectors/2);
6897
6898         /*
6899          * dt: time from mark until now
6900          * db: blocks written from mark until now
6901          * rt: remaining time
6902          *
6903          * rt is a sector_t, so could be 32bit or 64bit.
6904          * So we divide before multiply in case it is 32bit and close
6905          * to the limit.
6906          * We scale the divisor (db) by 32 to avoid losing precision
6907          * near the end of resync when the number of remaining sectors
6908          * is close to 'db'.
6909          * We then divide rt by 32 after multiplying by db to compensate.
6910          * The '+1' avoids division by zero if db is very small.
6911          */
6912         dt = ((jiffies - mddev->resync_mark) / HZ);
6913         if (!dt) dt++;
6914         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6915                 - mddev->resync_mark_cnt;
6916
6917         rt = max_sectors - resync;    /* number of remaining sectors */
6918         sector_div(rt, db/32+1);
6919         rt *= dt;
6920         rt >>= 5;
6921
6922         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6923                    ((unsigned long)rt % 60)/6);
6924
6925         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6926 }
6927
6928 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6929 {
6930         struct list_head *tmp;
6931         loff_t l = *pos;
6932         struct mddev *mddev;
6933
6934         if (l >= 0x10000)
6935                 return NULL;
6936         if (!l--)
6937                 /* header */
6938                 return (void*)1;
6939
6940         spin_lock(&all_mddevs_lock);
6941         list_for_each(tmp,&all_mddevs)
6942                 if (!l--) {
6943                         mddev = list_entry(tmp, struct mddev, all_mddevs);
6944                         mddev_get(mddev);
6945                         spin_unlock(&all_mddevs_lock);
6946                         return mddev;
6947                 }
6948         spin_unlock(&all_mddevs_lock);
6949         if (!l--)
6950                 return (void*)2;/* tail */
6951         return NULL;
6952 }
6953
6954 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6955 {
6956         struct list_head *tmp;
6957         struct mddev *next_mddev, *mddev = v;
6958         
6959         ++*pos;
6960         if (v == (void*)2)
6961                 return NULL;
6962
6963         spin_lock(&all_mddevs_lock);
6964         if (v == (void*)1)
6965                 tmp = all_mddevs.next;
6966         else
6967                 tmp = mddev->all_mddevs.next;
6968         if (tmp != &all_mddevs)
6969                 next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
6970         else {
6971                 next_mddev = (void*)2;
6972                 *pos = 0x10000;
6973         }               
6974         spin_unlock(&all_mddevs_lock);
6975
6976         if (v != (void*)1)
6977                 mddev_put(mddev);
6978         return next_mddev;
6979
6980 }
6981
6982 static void md_seq_stop(struct seq_file *seq, void *v)
6983 {
6984         struct mddev *mddev = v;
6985
6986         if (mddev && v != (void*)1 && v != (void*)2)
6987                 mddev_put(mddev);
6988 }
6989
6990 static int md_seq_show(struct seq_file *seq, void *v)
6991 {
6992         struct mddev *mddev = v;
6993         sector_t sectors;
6994         struct md_rdev *rdev;
6995
6996         if (v == (void*)1) {
6997                 struct md_personality *pers;
6998                 seq_printf(seq, "Personalities : ");
6999                 spin_lock(&pers_lock);
7000                 list_for_each_entry(pers, &pers_list, list)
7001                         seq_printf(seq, "[%s] ", pers->name);
7002
7003                 spin_unlock(&pers_lock);
7004                 seq_printf(seq, "\n");
7005                 seq->poll_event = atomic_read(&md_event_count);
7006                 return 0;
7007         }
7008         if (v == (void*)2) {
7009                 status_unused(seq);
7010                 return 0;
7011         }
7012
7013         if (mddev_lock(mddev) < 0)
7014                 return -EINTR;
7015
7016         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
7017                 seq_printf(seq, "%s : %sactive", mdname(mddev),
7018                                                 mddev->pers ? "" : "in");
7019                 if (mddev->pers) {
7020                         if (mddev->ro==1)
7021                                 seq_printf(seq, " (read-only)");
7022                         if (mddev->ro==2)
7023                                 seq_printf(seq, " (auto-read-only)");
7024                         seq_printf(seq, " %s", mddev->pers->name);
7025                 }
7026
7027                 sectors = 0;
7028                 rdev_for_each(rdev, mddev) {
7029                         char b[BDEVNAME_SIZE];
7030                         seq_printf(seq, " %s[%d]",
7031                                 bdevname(rdev->bdev,b), rdev->desc_nr);
7032                         if (test_bit(WriteMostly, &rdev->flags))
7033                                 seq_printf(seq, "(W)");
7034                         if (test_bit(Faulty, &rdev->flags)) {
7035                                 seq_printf(seq, "(F)");
7036                                 continue;
7037                         }
7038                         if (rdev->raid_disk < 0)
7039                                 seq_printf(seq, "(S)"); /* spare */
7040                         if (test_bit(Replacement, &rdev->flags))
7041                                 seq_printf(seq, "(R)");
7042                         sectors += rdev->sectors;
7043                 }
7044
7045                 if (!list_empty(&mddev->disks)) {
7046                         if (mddev->pers)
7047                                 seq_printf(seq, "\n      %llu blocks",
7048                                            (unsigned long long)
7049                                            mddev->array_sectors / 2);
7050                         else
7051                                 seq_printf(seq, "\n      %llu blocks",
7052                                            (unsigned long long)sectors / 2);
7053                 }
7054                 if (mddev->persistent) {
7055                         if (mddev->major_version != 0 ||
7056                             mddev->minor_version != 90) {
7057                                 seq_printf(seq," super %d.%d",
7058                                            mddev->major_version,
7059                                            mddev->minor_version);
7060                         }
7061                 } else if (mddev->external)
7062                         seq_printf(seq, " super external:%s",
7063                                    mddev->metadata_type);
7064                 else
7065                         seq_printf(seq, " super non-persistent");
7066
7067                 if (mddev->pers) {
7068                         mddev->pers->status(seq, mddev);
7069                         seq_printf(seq, "\n      ");
7070                         if (mddev->pers->sync_request) {
7071                                 if (mddev->curr_resync > 2) {
7072                                         status_resync(seq, mddev);
7073                                         seq_printf(seq, "\n      ");
7074                                 } else if (mddev->curr_resync >= 1)
7075                                         seq_printf(seq, "\tresync=DELAYED\n      ");
7076                                 else if (mddev->recovery_cp < MaxSector)
7077                                         seq_printf(seq, "\tresync=PENDING\n      ");
7078                         }
7079                 } else
7080                         seq_printf(seq, "\n       ");
7081
7082                 bitmap_status(seq, mddev->bitmap);
7083
7084                 seq_printf(seq, "\n");
7085         }
7086         mddev_unlock(mddev);
7087         
7088         return 0;
7089 }
7090
7091 static const struct seq_operations md_seq_ops = {
7092         .start  = md_seq_start,
7093         .next   = md_seq_next,
7094         .stop   = md_seq_stop,
7095         .show   = md_seq_show,
7096 };
7097
7098 static int md_seq_open(struct inode *inode, struct file *file)
7099 {
7100         struct seq_file *seq;
7101         int error;
7102
7103         error = seq_open(file, &md_seq_ops);
7104         if (error)
7105                 return error;
7106
7107         seq = file->private_data;
7108         seq->poll_event = atomic_read(&md_event_count);
7109         return error;
7110 }
7111
7112 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7113 {
7114         struct seq_file *seq = filp->private_data;
7115         int mask;
7116
7117         poll_wait(filp, &md_event_waiters, wait);
7118
7119         /* always allow read */
7120         mask = POLLIN | POLLRDNORM;
7121
7122         if (seq->poll_event != atomic_read(&md_event_count))
7123                 mask |= POLLERR | POLLPRI;
7124         return mask;
7125 }
7126
7127 static const struct file_operations md_seq_fops = {
7128         .owner          = THIS_MODULE,
7129         .open           = md_seq_open,
7130         .read           = seq_read,
7131         .llseek         = seq_lseek,
7132         .release        = seq_release_private,
7133         .poll           = mdstat_poll,
7134 };
7135
7136 int register_md_personality(struct md_personality *p)
7137 {
7138         spin_lock(&pers_lock);
7139         list_add_tail(&p->list, &pers_list);
7140         printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
7141         spin_unlock(&pers_lock);
7142         return 0;
7143 }
7144
7145 int unregister_md_personality(struct md_personality *p)
7146 {
7147         printk(KERN_INFO "md: %s personality unregistered\n", p->name);
7148         spin_lock(&pers_lock);
7149         list_del_init(&p->list);
7150         spin_unlock(&pers_lock);
7151         return 0;
7152 }
7153
7154 static int is_mddev_idle(struct mddev *mddev, int init)
7155 {
7156         struct md_rdev * rdev;
7157         int idle;
7158         int curr_events;
7159
7160         idle = 1;
7161         rcu_read_lock();
7162         rdev_for_each_rcu(rdev, mddev) {
7163                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
7164                 curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
7165                               (int)part_stat_read(&disk->part0, sectors[1]) -
7166                               atomic_read(&disk->sync_io);
7167                 /* sync IO will cause sync_io to increase before the disk_stats
7168                  * as sync_io is counted when a request starts, and
7169                  * disk_stats is counted when it completes.
7170                  * So resync activity will cause curr_events to be smaller than
7171                  * when there was no such activity.
7172                  * non-sync IO will cause disk_stat to increase without
7173                  * increasing sync_io so curr_events will (eventually)
7174                  * be larger than it was before.  Once it becomes
7175                  * substantially larger, the test below will cause
7176                  * the array to appear non-idle, and resync will slow
7177                  * down.
7178                  * If there is a lot of outstanding resync activity when
7179                  * we set last_event to curr_events, then all that activity
7180                  * completing might cause the array to appear non-idle
7181                  * and resync will be slowed down even though there might
7182                  * not have been non-resync activity.  This will only
7183                  * happen once though.  'last_events' will soon reflect
7184                  * the state where there is little or no outstanding
7185                  * resync requests, and further resync activity will
7186                  * always make curr_events less than last_events.
7187                  *
7188                  */
7189                 if (init || curr_events - rdev->last_events > 64) {
7190                         rdev->last_events = curr_events;
7191                         idle = 0;
7192                 }
7193         }
7194         rcu_read_unlock();
7195         return idle;
7196 }
7197
7198 void md_done_sync(struct mddev *mddev, int blocks, int ok)
7199 {
7200         /* another "blocks" (512byte) blocks have been synced */
7201         atomic_sub(blocks, &mddev->recovery_active);
7202         wake_up(&mddev->recovery_wait);
7203         if (!ok) {
7204                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7205                 set_bit(MD_RECOVERY_ERROR, &mddev->recovery);
7206                 md_wakeup_thread(mddev->thread);
7207                 // stop recovery, signal do_sync ....
7208         }
7209 }
7210
7211
7212 /* md_write_start(mddev, bi)
7213  * If we need to update some array metadata (e.g. 'active' flag
7214  * in superblock) before writing, schedule a superblock update
7215  * and wait for it to complete.
7216  */
7217 void md_write_start(struct mddev *mddev, struct bio *bi)
7218 {
7219         int did_change = 0;
7220         if (bio_data_dir(bi) != WRITE)
7221                 return;
7222
7223         BUG_ON(mddev->ro == 1);
7224         if (mddev->ro == 2) {
7225                 /* need to switch to read/write */
7226                 mddev->ro = 0;
7227                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7228                 md_wakeup_thread(mddev->thread);
7229                 md_wakeup_thread(mddev->sync_thread);
7230                 did_change = 1;
7231         }
7232         atomic_inc(&mddev->writes_pending);
7233         if (mddev->safemode == 1)
7234                 mddev->safemode = 0;
7235         if (mddev->in_sync) {
7236                 spin_lock_irq(&mddev->write_lock);
7237                 if (mddev->in_sync) {
7238                         mddev->in_sync = 0;
7239                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7240                         set_bit(MD_CHANGE_PENDING, &mddev->flags);
7241                         md_wakeup_thread(mddev->thread);
7242                         did_change = 1;
7243                 }
7244                 spin_unlock_irq(&mddev->write_lock);
7245         }
7246         if (did_change)
7247                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7248         wait_event(mddev->sb_wait,
7249                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
7250 }
7251
7252 void md_write_end(struct mddev *mddev)
7253 {
7254         if (atomic_dec_and_test(&mddev->writes_pending)) {
7255                 if (mddev->safemode == 2)
7256                         md_wakeup_thread(mddev->thread);
7257                 else if (mddev->safemode_delay)
7258                         mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
7259         }
7260 }
7261
7262 /* md_allow_write(mddev)
7263  * Calling this ensures that the array is marked 'active' so that writes
7264  * may proceed without blocking.  It is important to call this before
7265  * attempting a GFP_KERNEL allocation while holding the mddev lock.
7266  * Must be called with mddev_lock held.
7267  *
7268  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
7269  * is dropped, so return -EAGAIN after notifying userspace.
7270  */
7271 int md_allow_write(struct mddev *mddev)
7272 {
7273         if (!mddev->pers)
7274                 return 0;
7275         if (mddev->ro)
7276                 return 0;
7277         if (!mddev->pers->sync_request)
7278                 return 0;
7279
7280         spin_lock_irq(&mddev->write_lock);
7281         if (mddev->in_sync) {
7282                 mddev->in_sync = 0;
7283                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7284                 set_bit(MD_CHANGE_PENDING, &mddev->flags);
7285                 if (mddev->safemode_delay &&
7286                     mddev->safemode == 0)
7287                         mddev->safemode = 1;
7288                 spin_unlock_irq(&mddev->write_lock);
7289                 md_update_sb(mddev, 0);
7290                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7291         } else
7292                 spin_unlock_irq(&mddev->write_lock);
7293
7294         if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
7295                 return -EAGAIN;
7296         else
7297                 return 0;
7298 }
7299 EXPORT_SYMBOL_GPL(md_allow_write);
7300
7301 #define SYNC_MARKS      10
7302 #define SYNC_MARK_STEP  (3*HZ)
7303 #define UPDATE_FREQUENCY (5*60*HZ)
7304 void md_do_sync(struct md_thread *thread)
7305 {
7306         struct mddev *mddev = thread->mddev;
7307         struct mddev *mddev2;
7308         unsigned int currspeed = 0,
7309                  window;
7310         sector_t max_sectors,j, io_sectors;
7311         unsigned long mark[SYNC_MARKS];
7312         unsigned long update_time;
7313         sector_t mark_cnt[SYNC_MARKS];
7314         int last_mark,m;
7315         struct list_head *tmp;
7316         sector_t last_check;
7317         int skipped = 0;
7318         struct md_rdev *rdev;
7319         char *desc;
7320         struct blk_plug plug;
7321
7322         /* just incase thread restarts... */
7323         if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7324                 return;
7325         if (mddev->ro) /* never try to sync a read-only array */
7326                 return;
7327
7328         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7329                 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
7330                         desc = "data-check";
7331                 else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7332                         desc = "requested-resync";
7333                 else
7334                         desc = "resync";
7335         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7336                 desc = "reshape";
7337         else
7338                 desc = "recovery";
7339
7340         /* we overload curr_resync somewhat here.
7341          * 0 == not engaged in resync at all
7342          * 2 == checking that there is no conflict with another sync
7343          * 1 == like 2, but have yielded to allow conflicting resync to
7344          *              commense
7345          * other == active in resync - this many blocks
7346          *
7347          * Before starting a resync we must have set curr_resync to
7348          * 2, and then checked that every "conflicting" array has curr_resync
7349          * less than ours.  When we find one that is the same or higher
7350          * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
7351          * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
7352          * This will mean we have to start checking from the beginning again.
7353          *
7354          */
7355
7356         do {
7357                 mddev->curr_resync = 2;
7358
7359         try_again:
7360                 if (kthread_should_stop())
7361                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7362
7363                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7364                         goto skip;
7365                 for_each_mddev(mddev2, tmp) {
7366                         if (mddev2 == mddev)
7367                                 continue;
7368                         if (!mddev->parallel_resync
7369                         &&  mddev2->curr_resync
7370                         &&  match_mddev_units(mddev, mddev2)) {
7371                                 DEFINE_WAIT(wq);
7372                                 if (mddev < mddev2 && mddev->curr_resync == 2) {
7373                                         /* arbitrarily yield */
7374                                         mddev->curr_resync = 1;
7375                                         wake_up(&resync_wait);
7376                                 }
7377                                 if (mddev > mddev2 && mddev->curr_resync == 1)
7378                                         /* no need to wait here, we can wait the next
7379                                          * time 'round when curr_resync == 2
7380                                          */
7381                                         continue;
7382                                 /* We need to wait 'interruptible' so as not to
7383                                  * contribute to the load average, and not to
7384                                  * be caught by 'softlockup'
7385                                  */
7386                                 prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7387                                 if (!kthread_should_stop() &&
7388                                     mddev2->curr_resync >= mddev->curr_resync) {
7389                                         printk(KERN_INFO "md: delaying %s of %s"
7390                                                " until %s has finished (they"
7391                                                " share one or more physical units)\n",
7392                                                desc, mdname(mddev), mdname(mddev2));
7393                                         mddev_put(mddev2);
7394                                         if (signal_pending(current))
7395                                                 flush_signals(current);
7396                                         schedule();
7397                                         finish_wait(&resync_wait, &wq);
7398                                         goto try_again;
7399                                 }
7400                                 finish_wait(&resync_wait, &wq);
7401                         }
7402                 }
7403         } while (mddev->curr_resync < 2);
7404
7405         j = 0;
7406         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7407                 /* resync follows the size requested by the personality,
7408                  * which defaults to physical size, but can be virtual size
7409                  */
7410                 max_sectors = mddev->resync_max_sectors;
7411                 atomic64_set(&mddev->resync_mismatches, 0);
7412                 /* we don't use the checkpoint if there's a bitmap */
7413                 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7414                         j = mddev->resync_min;
7415                 else if (!mddev->bitmap)
7416                         j = mddev->recovery_cp;
7417
7418         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7419                 max_sectors = mddev->resync_max_sectors;
7420         else {
7421                 /* recovery follows the physical size of devices */
7422                 max_sectors = mddev->dev_sectors;
7423                 j = MaxSector;
7424                 rcu_read_lock();
7425                 rdev_for_each_rcu(rdev, mddev)
7426                         if (rdev->raid_disk >= 0 &&
7427                             !test_bit(Faulty, &rdev->flags) &&
7428                             !test_bit(In_sync, &rdev->flags) &&
7429                             rdev->recovery_offset < j)
7430                                 j = rdev->recovery_offset;
7431                 rcu_read_unlock();
7432         }
7433
7434         printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7435         printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7436                 " %d KB/sec/disk.\n", speed_min(mddev));
7437         printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7438                "(but not more than %d KB/sec) for %s.\n",
7439                speed_max(mddev), desc);
7440
7441         is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7442
7443         io_sectors = 0;
7444         for (m = 0; m < SYNC_MARKS; m++) {
7445                 mark[m] = jiffies;
7446                 mark_cnt[m] = io_sectors;
7447         }
7448         last_mark = 0;
7449         mddev->resync_mark = mark[last_mark];
7450         mddev->resync_mark_cnt = mark_cnt[last_mark];
7451
7452         /*
7453          * Tune reconstruction:
7454          */
7455         window = 32*(PAGE_SIZE/512);
7456         printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7457                 window/2, (unsigned long long)max_sectors/2);
7458
7459         atomic_set(&mddev->recovery_active, 0);
7460         last_check = 0;
7461
7462         if (j>2) {
7463                 printk(KERN_INFO 
7464                        "md: resuming %s of %s from checkpoint.\n",
7465                        desc, mdname(mddev));
7466                 mddev->curr_resync = j;
7467         } else
7468                 mddev->curr_resync = 3; /* no longer delayed */
7469         mddev->curr_resync_completed = j;
7470         sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7471         md_new_event(mddev);
7472         update_time = jiffies;
7473
7474         blk_start_plug(&plug);
7475         while (j < max_sectors) {
7476                 sector_t sectors;
7477
7478                 skipped = 0;
7479
7480                 if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7481                     ((mddev->curr_resync > mddev->curr_resync_completed &&
7482                       (mddev->curr_resync - mddev->curr_resync_completed)
7483                       > (max_sectors >> 4)) ||
7484                      time_after_eq(jiffies, update_time + UPDATE_FREQUENCY) ||
7485                      (j - mddev->curr_resync_completed)*2
7486                      >= mddev->resync_max - mddev->curr_resync_completed
7487                             )) {
7488                         /* time to update curr_resync_completed */
7489                         wait_event(mddev->recovery_wait,
7490                                    atomic_read(&mddev->recovery_active) == 0);
7491                         mddev->curr_resync_completed = j;
7492                         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
7493                             j > mddev->recovery_cp)
7494                                 mddev->recovery_cp = j;
7495                         update_time = jiffies;
7496                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7497                         sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7498                 }
7499
7500                 while (j >= mddev->resync_max && !kthread_should_stop()) {
7501                         /* As this condition is controlled by user-space,
7502                          * we can block indefinitely, so use '_interruptible'
7503                          * to avoid triggering warnings.
7504                          */
7505                         flush_signals(current); /* just in case */
7506                         wait_event_interruptible(mddev->recovery_wait,
7507                                                  mddev->resync_max > j
7508                                                  || kthread_should_stop());
7509                 }
7510
7511                 if (kthread_should_stop())
7512                         goto interrupted;
7513
7514                 sectors = mddev->pers->sync_request(mddev, j, &skipped,
7515                                                   currspeed < speed_min(mddev));
7516                 if (sectors == 0) {
7517                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7518                         goto out;
7519                 }
7520
7521                 if (!skipped) { /* actual IO requested */
7522                         io_sectors += sectors;
7523                         atomic_add(sectors, &mddev->recovery_active);
7524                 }
7525
7526                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7527                         break;
7528
7529                 j += sectors;
7530                 if (j > 2)
7531                         mddev->curr_resync = j;
7532                 mddev->curr_mark_cnt = io_sectors;
7533                 if (last_check == 0)
7534                         /* this is the earliest that rebuild will be
7535                          * visible in /proc/mdstat
7536                          */
7537                         md_new_event(mddev);
7538
7539                 if (last_check + window > io_sectors || j == max_sectors)
7540                         continue;
7541
7542                 last_check = io_sectors;
7543         repeat:
7544                 if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
7545                         /* step marks */
7546                         int next = (last_mark+1) % SYNC_MARKS;
7547
7548                         mddev->resync_mark = mark[next];
7549                         mddev->resync_mark_cnt = mark_cnt[next];
7550                         mark[next] = jiffies;
7551                         mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
7552                         last_mark = next;
7553                 }
7554
7555
7556                 if (kthread_should_stop())
7557                         goto interrupted;
7558
7559
7560                 /*
7561                  * this loop exits only if either when we are slower than
7562                  * the 'hard' speed limit, or the system was IO-idle for
7563                  * a jiffy.
7564                  * the system might be non-idle CPU-wise, but we only care
7565                  * about not overloading the IO subsystem. (things like an
7566                  * e2fsck being done on the RAID array should execute fast)
7567                  */
7568                 cond_resched();
7569
7570                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
7571                         /((jiffies-mddev->resync_mark)/HZ +1) +1;
7572
7573                 if (currspeed > speed_min(mddev)) {
7574                         if ((currspeed > speed_max(mddev)) ||
7575                                         !is_mddev_idle(mddev, 0)) {
7576                                 msleep(500);
7577                                 goto repeat;
7578                         }
7579                 }
7580         }
7581         printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
7582         /*
7583          * this also signals 'finished resyncing' to md_stop
7584          */
7585  out:
7586         blk_finish_plug(&plug);
7587         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
7588
7589         /* tell personality that we are finished */
7590         mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
7591
7592         if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
7593             mddev->curr_resync > 2) {
7594                 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7595                         if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7596                                 if (mddev->curr_resync >= mddev->recovery_cp) {
7597                                         printk(KERN_INFO
7598                                                "md: checkpointing %s of %s.\n",
7599                                                desc, mdname(mddev));
7600                                         if (test_bit(MD_RECOVERY_ERROR,
7601                                                 &mddev->recovery))
7602                                                 mddev->recovery_cp =
7603                                                         mddev->curr_resync_completed;
7604                                         else
7605                                                 mddev->recovery_cp =
7606                                                         mddev->curr_resync;
7607                                 }
7608                         } else
7609                                 mddev->recovery_cp = MaxSector;
7610                 } else {
7611                         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7612                                 mddev->curr_resync = MaxSector;
7613                         rcu_read_lock();
7614                         rdev_for_each_rcu(rdev, mddev)
7615                                 if (rdev->raid_disk >= 0 &&
7616                                     mddev->delta_disks >= 0 &&
7617                                     !test_bit(Faulty, &rdev->flags) &&
7618                                     !test_bit(In_sync, &rdev->flags) &&
7619                                     rdev->recovery_offset < mddev->curr_resync)
7620                                         rdev->recovery_offset = mddev->curr_resync;
7621                         rcu_read_unlock();
7622                 }
7623         }
7624  skip:
7625         set_bit(MD_CHANGE_DEVS, &mddev->flags);
7626
7627         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7628                 /* We completed so min/max setting can be forgotten if used. */
7629                 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7630                         mddev->resync_min = 0;
7631                 mddev->resync_max = MaxSector;
7632         } else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7633                 mddev->resync_min = mddev->curr_resync_completed;
7634         mddev->curr_resync = 0;
7635         wake_up(&resync_wait);
7636         set_bit(MD_RECOVERY_DONE, &mddev->recovery);
7637         md_wakeup_thread(mddev->thread);
7638         return;
7639
7640  interrupted:
7641         /*
7642          * got a signal, exit.
7643          */
7644         printk(KERN_INFO
7645                "md: md_do_sync() got signal ... exiting\n");
7646         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7647         goto out;
7648
7649 }
7650 EXPORT_SYMBOL_GPL(md_do_sync);
7651
7652 static int remove_and_add_spares(struct mddev *mddev)
7653 {
7654         struct md_rdev *rdev;
7655         int spares = 0;
7656         int removed = 0;
7657
7658         rdev_for_each(rdev, mddev)
7659                 if (rdev->raid_disk >= 0 &&
7660                     !test_bit(Blocked, &rdev->flags) &&
7661                     (test_bit(Faulty, &rdev->flags) ||
7662                      ! test_bit(In_sync, &rdev->flags)) &&
7663                     atomic_read(&rdev->nr_pending)==0) {
7664                         if (mddev->pers->hot_remove_disk(
7665                                     mddev, rdev) == 0) {
7666                                 sysfs_unlink_rdev(mddev, rdev);
7667                                 rdev->raid_disk = -1;
7668                                 removed++;
7669                         }
7670                 }
7671         if (removed && mddev->kobj.sd)
7672                 sysfs_notify(&mddev->kobj, NULL, "degraded");
7673
7674         rdev_for_each(rdev, mddev) {
7675                 if (rdev->raid_disk >= 0 &&
7676                     !test_bit(In_sync, &rdev->flags) &&
7677                     !test_bit(Faulty, &rdev->flags))
7678                         spares++;
7679                 if (rdev->raid_disk < 0
7680                     && !test_bit(Faulty, &rdev->flags)) {
7681                         rdev->recovery_offset = 0;
7682                         if (mddev->pers->
7683                             hot_add_disk(mddev, rdev) == 0) {
7684                                 if (sysfs_link_rdev(mddev, rdev))
7685                                         /* failure here is OK */;
7686                                 spares++;
7687                                 md_new_event(mddev);
7688                                 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7689                         }
7690                 }
7691         }
7692         if (removed)
7693                 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7694         return spares;
7695 }
7696
7697 static void reap_sync_thread(struct mddev *mddev)
7698 {
7699         struct md_rdev *rdev;
7700
7701         /* resync has finished, collect result */
7702         md_unregister_thread(&mddev->sync_thread);
7703         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7704             !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7705                 /* success...*/
7706                 /* activate any spares */
7707                 if (mddev->pers->spare_active(mddev)) {
7708                         sysfs_notify(&mddev->kobj, NULL,
7709                                      "degraded");
7710                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
7711                 }
7712         }
7713         if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7714             mddev->pers->finish_reshape)
7715                 mddev->pers->finish_reshape(mddev);
7716
7717         /* If array is no-longer degraded, then any saved_raid_disk
7718          * information must be scrapped.  Also if any device is now
7719          * In_sync we must scrape the saved_raid_disk for that device
7720          * do the superblock for an incrementally recovered device
7721          * written out.
7722          */
7723         rdev_for_each(rdev, mddev)
7724                 if (!mddev->degraded ||
7725                     test_bit(In_sync, &rdev->flags))
7726                         rdev->saved_raid_disk = -1;
7727
7728         md_update_sb(mddev, 1);
7729         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7730         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7731         clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7732         clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7733         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7734         /* flag recovery needed just to double check */
7735         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7736         sysfs_notify_dirent_safe(mddev->sysfs_action);
7737         md_new_event(mddev);
7738         if (mddev->event_work.func)
7739                 queue_work(md_misc_wq, &mddev->event_work);
7740 }
7741
7742 /*
7743  * This routine is regularly called by all per-raid-array threads to
7744  * deal with generic issues like resync and super-block update.
7745  * Raid personalities that don't have a thread (linear/raid0) do not
7746  * need this as they never do any recovery or update the superblock.
7747  *
7748  * It does not do any resync itself, but rather "forks" off other threads
7749  * to do that as needed.
7750  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7751  * "->recovery" and create a thread at ->sync_thread.
7752  * When the thread finishes it sets MD_RECOVERY_DONE
7753  * and wakeups up this thread which will reap the thread and finish up.
7754  * This thread also removes any faulty devices (with nr_pending == 0).
7755  *
7756  * The overall approach is:
7757  *  1/ if the superblock needs updating, update it.
7758  *  2/ If a recovery thread is running, don't do anything else.
7759  *  3/ If recovery has finished, clean up, possibly marking spares active.
7760  *  4/ If there are any faulty devices, remove them.
7761  *  5/ If array is degraded, try to add spares devices
7762  *  6/ If array has spares or is not in-sync, start a resync thread.
7763  */
7764 void md_check_recovery(struct mddev *mddev)
7765 {
7766         if (mddev->suspended)
7767                 return;
7768
7769         if (mddev->bitmap)
7770                 bitmap_daemon_work(mddev);
7771
7772         if (signal_pending(current)) {
7773                 if (mddev->pers->sync_request && !mddev->external) {
7774                         printk(KERN_INFO "md: %s in immediate safe mode\n",
7775                                mdname(mddev));
7776                         mddev->safemode = 2;
7777                 }
7778                 flush_signals(current);
7779         }
7780
7781         if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7782                 return;
7783         if ( ! (
7784                 (mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7785                 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7786                 test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7787                 (mddev->external == 0 && mddev->safemode == 1) ||
7788                 (mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7789                  && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7790                 ))
7791                 return;
7792
7793         if (mddev_trylock(mddev)) {
7794                 int spares = 0;
7795
7796                 if (mddev->ro) {
7797                         /* Only thing we do on a ro array is remove
7798                          * failed devices.
7799                          */
7800                         struct md_rdev *rdev;
7801                         rdev_for_each(rdev, mddev)
7802                                 if (rdev->raid_disk >= 0 &&
7803                                     !test_bit(Blocked, &rdev->flags) &&
7804                                     test_bit(Faulty, &rdev->flags) &&
7805                                     atomic_read(&rdev->nr_pending)==0) {
7806                                         if (mddev->pers->hot_remove_disk(
7807                                                     mddev, rdev) == 0) {
7808                                                 sysfs_unlink_rdev(mddev, rdev);
7809                                                 rdev->raid_disk = -1;
7810                                         }
7811                                 }
7812                         clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7813                         goto unlock;
7814                 }
7815
7816                 if (!mddev->external) {
7817                         int did_change = 0;
7818                         spin_lock_irq(&mddev->write_lock);
7819                         if (mddev->safemode &&
7820                             !atomic_read(&mddev->writes_pending) &&
7821                             !mddev->in_sync &&
7822                             mddev->recovery_cp == MaxSector) {
7823                                 mddev->in_sync = 1;
7824                                 did_change = 1;
7825                                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7826                         }
7827                         if (mddev->safemode == 1)
7828                                 mddev->safemode = 0;
7829                         spin_unlock_irq(&mddev->write_lock);
7830                         if (did_change)
7831                                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7832                 }
7833
7834                 if (mddev->flags)
7835                         md_update_sb(mddev, 0);
7836
7837                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7838                     !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7839                         /* resync/recovery still happening */
7840                         clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7841                         goto unlock;
7842                 }
7843                 if (mddev->sync_thread) {
7844                         reap_sync_thread(mddev);
7845                         goto unlock;
7846                 }
7847                 /* Set RUNNING before clearing NEEDED to avoid
7848                  * any transients in the value of "sync_action".
7849                  */
7850                 mddev->curr_resync_completed = 0;
7851                 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7852                 /* Clear some bits that don't mean anything, but
7853                  * might be left set
7854                  */
7855                 clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7856                 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7857
7858                 if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7859                     test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7860                         goto unlock;
7861                 /* no recovery is running.
7862                  * remove any failed drives, then
7863                  * add spares if possible.
7864                  * Spares are also removed and re-added, to allow
7865                  * the personality to fail the re-add.
7866                  */
7867
7868                 if (mddev->reshape_position != MaxSector) {
7869                         if (mddev->pers->check_reshape == NULL ||
7870                             mddev->pers->check_reshape(mddev) != 0)
7871                                 /* Cannot proceed */
7872                                 goto unlock;
7873                         set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7874                         clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7875                 } else if ((spares = remove_and_add_spares(mddev))) {
7876                         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7877                         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7878                         clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7879                         set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7880                 } else if (mddev->recovery_cp < MaxSector) {
7881                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7882                         clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7883                 } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7884                         /* nothing to be done ... */
7885                         goto unlock;
7886
7887                 if (mddev->pers->sync_request) {
7888                         if (spares) {
7889                                 /* We are adding a device or devices to an array
7890                                  * which has the bitmap stored on all devices.
7891                                  * So make sure all bitmap pages get written
7892                                  */
7893                                 bitmap_write_all(mddev->bitmap);
7894                         }
7895                         mddev->sync_thread = md_register_thread(md_do_sync,
7896                                                                 mddev,
7897                                                                 "resync");
7898                         if (!mddev->sync_thread) {
7899                                 printk(KERN_ERR "%s: could not start resync"
7900                                         " thread...\n", 
7901                                         mdname(mddev));
7902                                 /* leave the spares where they are, it shouldn't hurt */
7903                                 clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7904                                 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7905                                 clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7906                                 clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7907                                 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7908                         } else
7909                                 md_wakeup_thread(mddev->sync_thread);
7910                         sysfs_notify_dirent_safe(mddev->sysfs_action);
7911                         md_new_event(mddev);
7912                 }
7913         unlock:
7914                 if (!mddev->sync_thread) {
7915                         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7916                         if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7917                                                &mddev->recovery))
7918                                 if (mddev->sysfs_action)
7919                                         sysfs_notify_dirent_safe(mddev->sysfs_action);
7920                 }
7921                 mddev_unlock(mddev);
7922         }
7923 }
7924
7925 void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
7926 {
7927         sysfs_notify_dirent_safe(rdev->sysfs_state);
7928         wait_event_timeout(rdev->blocked_wait,
7929                            !test_bit(Blocked, &rdev->flags) &&
7930                            !test_bit(BlockedBadBlocks, &rdev->flags),
7931                            msecs_to_jiffies(5000));
7932         rdev_dec_pending(rdev, mddev);
7933 }
7934 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7935
7936 void md_finish_reshape(struct mddev *mddev)
7937 {
7938         /* called be personality module when reshape completes. */
7939         struct md_rdev *rdev;
7940
7941         rdev_for_each(rdev, mddev) {
7942                 if (rdev->data_offset > rdev->new_data_offset)
7943                         rdev->sectors += rdev->data_offset - rdev->new_data_offset;
7944                 else
7945                         rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
7946                 rdev->data_offset = rdev->new_data_offset;
7947         }
7948 }
7949 EXPORT_SYMBOL(md_finish_reshape);
7950
7951 /* Bad block management.
7952  * We can record which blocks on each device are 'bad' and so just
7953  * fail those blocks, or that stripe, rather than the whole device.
7954  * Entries in the bad-block table are 64bits wide.  This comprises:
7955  * Length of bad-range, in sectors: 0-511 for lengths 1-512
7956  * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
7957  *  A 'shift' can be set so that larger blocks are tracked and
7958  *  consequently larger devices can be covered.
7959  * 'Acknowledged' flag - 1 bit. - the most significant bit.
7960  *
7961  * Locking of the bad-block table uses a seqlock so md_is_badblock
7962  * might need to retry if it is very unlucky.
7963  * We will sometimes want to check for bad blocks in a bi_end_io function,
7964  * so we use the write_seqlock_irq variant.
7965  *
7966  * When looking for a bad block we specify a range and want to
7967  * know if any block in the range is bad.  So we binary-search
7968  * to the last range that starts at-or-before the given endpoint,
7969  * (or "before the sector after the target range")
7970  * then see if it ends after the given start.
7971  * We return
7972  *  0 if there are no known bad blocks in the range
7973  *  1 if there are known bad block which are all acknowledged
7974  * -1 if there are bad blocks which have not yet been acknowledged in metadata.
7975  * plus the start/length of the first bad section we overlap.
7976  */
7977 int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
7978                    sector_t *first_bad, int *bad_sectors)
7979 {
7980         int hi;
7981         int lo;
7982         u64 *p = bb->page;
7983         int rv;
7984         sector_t target = s + sectors;
7985         unsigned seq;
7986
7987         if (bb->shift > 0) {
7988                 /* round the start down, and the end up */
7989                 s >>= bb->shift;
7990                 target += (1<<bb->shift) - 1;
7991                 target >>= bb->shift;
7992                 sectors = target - s;
7993         }
7994         /* 'target' is now the first block after the bad range */
7995
7996 retry:
7997         seq = read_seqbegin(&bb->lock);
7998         lo = 0;
7999         rv = 0;
8000         hi = bb->count;
8001
8002         /* Binary search between lo and hi for 'target'
8003          * i.e. for the last range that starts before 'target'
8004          */
8005         /* INVARIANT: ranges before 'lo' and at-or-after 'hi'
8006          * are known not to be the last range before target.
8007          * VARIANT: hi-lo is the number of possible
8008          * ranges, and decreases until it reaches 1
8009          */
8010         while (hi - lo > 1) {
8011                 int mid = (lo + hi) / 2;
8012                 sector_t a = BB_OFFSET(p[mid]);
8013                 if (a < target)
8014                         /* This could still be the one, earlier ranges
8015                          * could not. */
8016                         lo = mid;
8017                 else
8018                         /* This and later ranges are definitely out. */
8019                         hi = mid;
8020         }
8021         /* 'lo' might be the last that started before target, but 'hi' isn't */
8022         if (hi > lo) {
8023                 /* need to check all range that end after 's' to see if
8024                  * any are unacknowledged.
8025                  */
8026                 while (lo >= 0 &&
8027                        BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
8028                         if (BB_OFFSET(p[lo]) < target) {
8029                                 /* starts before the end, and finishes after
8030                                  * the start, so they must overlap
8031                                  */
8032                                 if (rv != -1 && BB_ACK(p[lo]))
8033                                         rv = 1;
8034                                 else
8035                                         rv = -1;
8036                                 *first_bad = BB_OFFSET(p[lo]);
8037                                 *bad_sectors = BB_LEN(p[lo]);
8038                         }
8039                         lo--;
8040                 }
8041         }
8042
8043         if (read_seqretry(&bb->lock, seq))
8044                 goto retry;
8045
8046         return rv;
8047 }
8048 EXPORT_SYMBOL_GPL(md_is_badblock);
8049
8050 /*
8051  * Add a range of bad blocks to the table.
8052  * This might extend the table, or might contract it
8053  * if two adjacent ranges can be merged.
8054  * We binary-search to find the 'insertion' point, then
8055  * decide how best to handle it.
8056  */
8057 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
8058                             int acknowledged)
8059 {
8060         u64 *p;
8061         int lo, hi;
8062         int rv = 1;
8063
8064         if (bb->shift < 0)
8065                 /* badblocks are disabled */
8066                 return 0;
8067
8068         if (bb->shift) {
8069                 /* round the start down, and the end up */
8070                 sector_t next = s + sectors;
8071                 s >>= bb->shift;
8072                 next += (1<<bb->shift) - 1;
8073                 next >>= bb->shift;
8074                 sectors = next - s;
8075         }
8076
8077         write_seqlock_irq(&bb->lock);
8078
8079         p = bb->page;
8080         lo = 0;
8081         hi = bb->count;
8082         /* Find the last range that starts at-or-before 's' */
8083         while (hi - lo > 1) {
8084                 int mid = (lo + hi) / 2;
8085                 sector_t a = BB_OFFSET(p[mid]);
8086                 if (a <= s)
8087                         lo = mid;
8088                 else
8089                         hi = mid;
8090         }
8091         if (hi > lo && BB_OFFSET(p[lo]) > s)
8092                 hi = lo;
8093
8094         if (hi > lo) {
8095                 /* we found a range that might merge with the start
8096                  * of our new range
8097                  */
8098                 sector_t a = BB_OFFSET(p[lo]);
8099                 sector_t e = a + BB_LEN(p[lo]);
8100                 int ack = BB_ACK(p[lo]);
8101                 if (e >= s) {
8102                         /* Yes, we can merge with a previous range */
8103                         if (s == a && s + sectors >= e)
8104                                 /* new range covers old */
8105                                 ack = acknowledged;
8106                         else
8107                                 ack = ack && acknowledged;
8108
8109                         if (e < s + sectors)
8110                                 e = s + sectors;
8111                         if (e - a <= BB_MAX_LEN) {
8112                                 p[lo] = BB_MAKE(a, e-a, ack);
8113                                 s = e;
8114                         } else {
8115                                 /* does not all fit in one range,
8116                                  * make p[lo] maximal
8117                                  */
8118                                 if (BB_LEN(p[lo]) != BB_MAX_LEN)
8119                                         p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
8120                                 s = a + BB_MAX_LEN;
8121                         }
8122                         sectors = e - s;
8123                 }
8124         }
8125         if (sectors && hi < bb->count) {
8126                 /* 'hi' points to the first range that starts after 's'.
8127                  * Maybe we can merge with the start of that range */
8128                 sector_t a = BB_OFFSET(p[hi]);
8129                 sector_t e = a + BB_LEN(p[hi]);
8130                 int ack = BB_ACK(p[hi]);
8131                 if (a <= s + sectors) {
8132                         /* merging is possible */
8133                         if (e <= s + sectors) {
8134                                 /* full overlap */
8135                                 e = s + sectors;
8136                                 ack = acknowledged;
8137                         } else
8138                                 ack = ack && acknowledged;
8139
8140                         a = s;
8141                         if (e - a <= BB_MAX_LEN) {
8142                                 p[hi] = BB_MAKE(a, e-a, ack);
8143                                 s = e;
8144                         } else {
8145                                 p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
8146                                 s = a + BB_MAX_LEN;
8147                         }
8148                         sectors = e - s;
8149                         lo = hi;
8150                         hi++;
8151                 }
8152         }
8153         if (sectors == 0 && hi < bb->count) {
8154                 /* we might be able to combine lo and hi */
8155                 /* Note: 's' is at the end of 'lo' */
8156                 sector_t a = BB_OFFSET(p[hi]);
8157                 int lolen = BB_LEN(p[lo]);
8158                 int hilen = BB_LEN(p[hi]);
8159                 int newlen = lolen + hilen - (s - a);
8160                 if (s >= a && newlen < BB_MAX_LEN) {
8161                         /* yes, we can combine them */
8162                         int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
8163                         p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
8164                         memmove(p + hi, p + hi + 1,
8165                                 (bb->count - hi - 1) * 8);
8166                         bb->count--;
8167                 }
8168         }
8169         while (sectors) {
8170                 /* didn't merge (it all).
8171                  * Need to add a range just before 'hi' */
8172                 if (bb->count >= MD_MAX_BADBLOCKS) {
8173                         /* No room for more */
8174                         rv = 0;
8175                         break;
8176                 } else {
8177                         int this_sectors = sectors;
8178                         memmove(p + hi + 1, p + hi,
8179                                 (bb->count - hi) * 8);
8180                         bb->count++;
8181
8182                         if (this_sectors > BB_MAX_LEN)
8183                                 this_sectors = BB_MAX_LEN;
8184                         p[hi] = BB_MAKE(s, this_sectors, acknowledged);
8185                         sectors -= this_sectors;
8186                         s += this_sectors;
8187                 }
8188         }
8189
8190         bb->changed = 1;
8191         if (!acknowledged)
8192                 bb->unacked_exist = 1;
8193         write_sequnlock_irq(&bb->lock);
8194
8195         return rv;
8196 }
8197
8198 int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8199                        int is_new)
8200 {
8201         int rv;
8202         if (is_new)
8203                 s += rdev->new_data_offset;
8204         else
8205                 s += rdev->data_offset;
8206         rv = md_set_badblocks(&rdev->badblocks,
8207                               s, sectors, 0);
8208         if (rv) {
8209                 /* Make sure they get written out promptly */
8210                 sysfs_notify_dirent_safe(rdev->sysfs_state);
8211                 set_bit(MD_CHANGE_CLEAN, &rdev->mddev->flags);
8212                 md_wakeup_thread(rdev->mddev->thread);
8213         }
8214         return rv;
8215 }
8216 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
8217
8218 /*
8219  * Remove a range of bad blocks from the table.
8220  * This may involve extending the table if we spilt a region,
8221  * but it must not fail.  So if the table becomes full, we just
8222  * drop the remove request.
8223  */
8224 static int md_clear_badblocks(struct badblocks *bb, sector_t s, int sectors)
8225 {
8226         u64 *p;
8227         int lo, hi;
8228         sector_t target = s + sectors;
8229         int rv = 0;
8230
8231         if (bb->shift > 0) {
8232                 /* When clearing we round the start up and the end down.
8233                  * This should not matter as the shift should align with
8234                  * the block size and no rounding should ever be needed.
8235                  * However it is better the think a block is bad when it
8236                  * isn't than to think a block is not bad when it is.
8237                  */
8238                 s += (1<<bb->shift) - 1;
8239                 s >>= bb->shift;
8240                 target >>= bb->shift;
8241                 sectors = target - s;
8242         }
8243
8244         write_seqlock_irq(&bb->lock);
8245
8246         p = bb->page;
8247         lo = 0;
8248         hi = bb->count;
8249         /* Find the last range that starts before 'target' */
8250         while (hi - lo > 1) {
8251                 int mid = (lo + hi) / 2;
8252                 sector_t a = BB_OFFSET(p[mid]);
8253                 if (a < target)
8254                         lo = mid;
8255                 else
8256                         hi = mid;
8257         }
8258         if (hi > lo) {
8259                 /* p[lo] is the last range that could overlap the
8260                  * current range.  Earlier ranges could also overlap,
8261                  * but only this one can overlap the end of the range.
8262                  */
8263                 if (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) {
8264                         /* Partial overlap, leave the tail of this range */
8265                         int ack = BB_ACK(p[lo]);
8266                         sector_t a = BB_OFFSET(p[lo]);
8267                         sector_t end = a + BB_LEN(p[lo]);
8268
8269                         if (a < s) {
8270                                 /* we need to split this range */
8271                                 if (bb->count >= MD_MAX_BADBLOCKS) {
8272                                         rv = 0;
8273                                         goto out;
8274                                 }
8275                                 memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
8276                                 bb->count++;
8277                                 p[lo] = BB_MAKE(a, s-a, ack);
8278                                 lo++;
8279                         }
8280                         p[lo] = BB_MAKE(target, end - target, ack);
8281                         /* there is no longer an overlap */
8282                         hi = lo;
8283                         lo--;
8284                 }
8285                 while (lo >= 0 &&
8286                        BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
8287                         /* This range does overlap */
8288                         if (BB_OFFSET(p[lo]) < s) {
8289                                 /* Keep the early parts of this range. */
8290                                 int ack = BB_ACK(p[lo]);
8291                                 sector_t start = BB_OFFSET(p[lo]);
8292                                 p[lo] = BB_MAKE(start, s - start, ack);
8293                                 /* now low doesn't overlap, so.. */
8294                                 break;
8295                         }
8296                         lo--;
8297                 }
8298                 /* 'lo' is strictly before, 'hi' is strictly after,
8299                  * anything between needs to be discarded
8300                  */
8301                 if (hi - lo > 1) {
8302                         memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
8303                         bb->count -= (hi - lo - 1);
8304                 }
8305         }
8306
8307         bb->changed = 1;
8308 out:
8309         write_sequnlock_irq(&bb->lock);
8310         return rv;
8311 }
8312
8313 int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8314                          int is_new)
8315 {
8316         if (is_new)
8317                 s += rdev->new_data_offset;
8318         else
8319                 s += rdev->data_offset;
8320         return md_clear_badblocks(&rdev->badblocks,
8321                                   s, sectors);
8322 }
8323 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
8324
8325 /*
8326  * Acknowledge all bad blocks in a list.
8327  * This only succeeds if ->changed is clear.  It is used by
8328  * in-kernel metadata updates
8329  */
8330 void md_ack_all_badblocks(struct badblocks *bb)
8331 {
8332         if (bb->page == NULL || bb->changed)
8333                 /* no point even trying */
8334                 return;
8335         write_seqlock_irq(&bb->lock);
8336
8337         if (bb->changed == 0 && bb->unacked_exist) {
8338                 u64 *p = bb->page;
8339                 int i;
8340                 for (i = 0; i < bb->count ; i++) {
8341                         if (!BB_ACK(p[i])) {
8342                                 sector_t start = BB_OFFSET(p[i]);
8343                                 int len = BB_LEN(p[i]);
8344                                 p[i] = BB_MAKE(start, len, 1);
8345                         }
8346                 }
8347                 bb->unacked_exist = 0;
8348         }
8349         write_sequnlock_irq(&bb->lock);
8350 }
8351 EXPORT_SYMBOL_GPL(md_ack_all_badblocks);
8352
8353 /* sysfs access to bad-blocks list.
8354  * We present two files.
8355  * 'bad-blocks' lists sector numbers and lengths of ranges that
8356  *    are recorded as bad.  The list is truncated to fit within
8357  *    the one-page limit of sysfs.
8358  *    Writing "sector length" to this file adds an acknowledged
8359  *    bad block list.
8360  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
8361  *    been acknowledged.  Writing to this file adds bad blocks
8362  *    without acknowledging them.  This is largely for testing.
8363  */
8364
8365 static ssize_t
8366 badblocks_show(struct badblocks *bb, char *page, int unack)
8367 {
8368         size_t len;
8369         int i;
8370         u64 *p = bb->page;
8371         unsigned seq;
8372
8373         if (bb->shift < 0)
8374                 return 0;
8375
8376 retry:
8377         seq = read_seqbegin(&bb->lock);
8378
8379         len = 0;
8380         i = 0;
8381
8382         while (len < PAGE_SIZE && i < bb->count) {
8383                 sector_t s = BB_OFFSET(p[i]);
8384                 unsigned int length = BB_LEN(p[i]);
8385                 int ack = BB_ACK(p[i]);
8386                 i++;
8387
8388                 if (unack && ack)
8389                         continue;
8390
8391                 len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
8392                                 (unsigned long long)s << bb->shift,
8393                                 length << bb->shift);
8394         }
8395         if (unack && len == 0)
8396                 bb->unacked_exist = 0;
8397
8398         if (read_seqretry(&bb->lock, seq))
8399                 goto retry;
8400
8401         return len;
8402 }
8403
8404 #define DO_DEBUG 1
8405
8406 static ssize_t
8407 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack)
8408 {
8409         unsigned long long sector;
8410         int length;
8411         char newline;
8412 #ifdef DO_DEBUG
8413         /* Allow clearing via sysfs *only* for testing/debugging.
8414          * Normally only a successful write may clear a badblock
8415          */
8416         int clear = 0;
8417         if (page[0] == '-') {
8418                 clear = 1;
8419                 page++;
8420         }
8421 #endif /* DO_DEBUG */
8422
8423         switch (sscanf(page, "%llu %d%c", &sector, &length, &newline)) {
8424         case 3:
8425                 if (newline != '\n')
8426                         return -EINVAL;
8427         case 2:
8428                 if (length <= 0)
8429                         return -EINVAL;
8430                 break;
8431         default:
8432                 return -EINVAL;
8433         }
8434
8435 #ifdef DO_DEBUG
8436         if (clear) {
8437                 md_clear_badblocks(bb, sector, length);
8438                 return len;
8439         }
8440 #endif /* DO_DEBUG */
8441         if (md_set_badblocks(bb, sector, length, !unack))
8442                 return len;
8443         else
8444                 return -ENOSPC;
8445 }
8446
8447 static int md_notify_reboot(struct notifier_block *this,
8448                             unsigned long code, void *x)
8449 {
8450         struct list_head *tmp;
8451         struct mddev *mddev;
8452         int need_delay = 0;
8453
8454         for_each_mddev(mddev, tmp) {
8455                 if (mddev_trylock(mddev)) {
8456                         if (mddev->pers)
8457                                 __md_stop_writes(mddev);
8458                         mddev->safemode = 2;
8459                         mddev_unlock(mddev);
8460                 }
8461                 need_delay = 1;
8462         }
8463         /*
8464          * certain more exotic SCSI devices are known to be
8465          * volatile wrt too early system reboots. While the
8466          * right place to handle this issue is the given
8467          * driver, we do want to have a safe RAID driver ...
8468          */
8469         if (need_delay)
8470                 mdelay(1000*1);
8471
8472         return NOTIFY_DONE;
8473 }
8474
8475 static struct notifier_block md_notifier = {
8476         .notifier_call  = md_notify_reboot,
8477         .next           = NULL,
8478         .priority       = INT_MAX, /* before any real devices */
8479 };
8480
8481 static void md_geninit(void)
8482 {
8483         pr_debug("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
8484
8485         proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
8486 }
8487
8488 static int __init md_init(void)
8489 {
8490         int ret = -ENOMEM;
8491
8492         md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
8493         if (!md_wq)
8494                 goto err_wq;
8495
8496         md_misc_wq = alloc_workqueue("md_misc", 0, 0);
8497         if (!md_misc_wq)
8498                 goto err_misc_wq;
8499
8500         if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
8501                 goto err_md;
8502
8503         if ((ret = register_blkdev(0, "mdp")) < 0)
8504                 goto err_mdp;
8505         mdp_major = ret;
8506
8507         blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
8508                             md_probe, NULL, NULL);
8509         blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
8510                             md_probe, NULL, NULL);
8511
8512         register_reboot_notifier(&md_notifier);
8513         raid_table_header = register_sysctl_table(raid_root_table);
8514
8515         md_geninit();
8516         return 0;
8517
8518 err_mdp:
8519         unregister_blkdev(MD_MAJOR, "md");
8520 err_md:
8521         destroy_workqueue(md_misc_wq);
8522 err_misc_wq:
8523         destroy_workqueue(md_wq);
8524 err_wq:
8525         return ret;
8526 }
8527
8528 #ifndef MODULE
8529
8530 /*
8531  * Searches all registered partitions for autorun RAID arrays
8532  * at boot time.
8533  */
8534
8535 static LIST_HEAD(all_detected_devices);
8536 struct detected_devices_node {
8537         struct list_head list;
8538         dev_t dev;
8539 };
8540
8541 void md_autodetect_dev(dev_t dev)
8542 {
8543         struct detected_devices_node *node_detected_dev;
8544
8545         node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
8546         if (node_detected_dev) {
8547                 node_detected_dev->dev = dev;
8548                 list_add_tail(&node_detected_dev->list, &all_detected_devices);
8549         } else {
8550                 printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
8551                         ", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
8552         }
8553 }
8554
8555
8556 static void autostart_arrays(int part)
8557 {
8558         struct md_rdev *rdev;
8559         struct detected_devices_node *node_detected_dev;
8560         dev_t dev;
8561         int i_scanned, i_passed;
8562
8563         i_scanned = 0;
8564         i_passed = 0;
8565
8566         printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
8567
8568         while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
8569                 i_scanned++;
8570                 node_detected_dev = list_entry(all_detected_devices.next,
8571                                         struct detected_devices_node, list);
8572                 list_del(&node_detected_dev->list);
8573                 dev = node_detected_dev->dev;
8574                 kfree(node_detected_dev);
8575                 rdev = md_import_device(dev,0, 90);
8576                 if (IS_ERR(rdev))
8577                         continue;
8578
8579                 if (test_bit(Faulty, &rdev->flags)) {
8580                         MD_BUG();
8581                         continue;
8582                 }
8583                 set_bit(AutoDetected, &rdev->flags);
8584                 list_add(&rdev->same_set, &pending_raid_disks);
8585                 i_passed++;
8586         }
8587
8588         printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
8589                                                 i_scanned, i_passed);
8590
8591         autorun_devices(part);
8592 }
8593
8594 #endif /* !MODULE */
8595
8596 static __exit void md_exit(void)
8597 {
8598         struct mddev *mddev;
8599         struct list_head *tmp;
8600
8601         blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
8602         blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
8603
8604         unregister_blkdev(MD_MAJOR,"md");
8605         unregister_blkdev(mdp_major, "mdp");
8606         unregister_reboot_notifier(&md_notifier);
8607         unregister_sysctl_table(raid_table_header);
8608         remove_proc_entry("mdstat", NULL);
8609         for_each_mddev(mddev, tmp) {
8610                 export_array(mddev);
8611                 mddev->hold_active = 0;
8612         }
8613         destroy_workqueue(md_misc_wq);
8614         destroy_workqueue(md_wq);
8615 }
8616
8617 subsys_initcall(md_init);
8618 module_exit(md_exit)
8619
8620 static int get_ro(char *buffer, struct kernel_param *kp)
8621 {
8622         return sprintf(buffer, "%d", start_readonly);
8623 }
8624 static int set_ro(const char *val, struct kernel_param *kp)
8625 {
8626         char *e;
8627         int num = simple_strtoul(val, &e, 10);
8628         if (*val && (*e == '\0' || *e == '\n')) {
8629                 start_readonly = num;
8630                 return 0;
8631         }
8632         return -EINVAL;
8633 }
8634
8635 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
8636 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
8637
8638 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
8639
8640 EXPORT_SYMBOL(register_md_personality);
8641 EXPORT_SYMBOL(unregister_md_personality);
8642 EXPORT_SYMBOL(md_error);
8643 EXPORT_SYMBOL(md_done_sync);
8644 EXPORT_SYMBOL(md_write_start);
8645 EXPORT_SYMBOL(md_write_end);
8646 EXPORT_SYMBOL(md_register_thread);
8647 EXPORT_SYMBOL(md_unregister_thread);
8648 EXPORT_SYMBOL(md_wakeup_thread);
8649 EXPORT_SYMBOL(md_check_recovery);
8650 MODULE_LICENSE("GPL");
8651 MODULE_DESCRIPTION("MD RAID framework");
8652 MODULE_ALIAS("md");
8653 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);