Pull dock-bay into release branch
[linux-2.6] / 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/module.h>
36 #include <linux/kernel.h>
37 #include <linux/kthread.h>
38 #include <linux/linkage.h>
39 #include <linux/raid/md.h>
40 #include <linux/raid/bitmap.h>
41 #include <linux/sysctl.h>
42 #include <linux/buffer_head.h> /* for invalidate_bdev */
43 #include <linux/poll.h>
44 #include <linux/mutex.h>
45 #include <linux/ctype.h>
46 #include <linux/freezer.h>
47
48 #include <linux/init.h>
49
50 #include <linux/file.h>
51
52 #ifdef CONFIG_KMOD
53 #include <linux/kmod.h>
54 #endif
55
56 #include <asm/unaligned.h>
57
58 #define MAJOR_NR MD_MAJOR
59 #define MD_DRIVER
60
61 /* 63 partitions with the alternate major number (mdp) */
62 #define MdpMinorShift 6
63
64 #define DEBUG 0
65 #define dprintk(x...) ((void)(DEBUG && printk(x)))
66
67
68 #ifndef MODULE
69 static void autostart_arrays (int part);
70 #endif
71
72 static LIST_HEAD(pers_list);
73 static DEFINE_SPINLOCK(pers_lock);
74
75 static void md_print_devices(void);
76
77 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
78
79 /*
80  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
81  * is 1000 KB/sec, so the extra system load does not show up that much.
82  * Increase it if you want to have more _guaranteed_ speed. Note that
83  * the RAID driver will use the maximum available bandwidth if the IO
84  * subsystem is idle. There is also an 'absolute maximum' reconstruction
85  * speed limit - in case reconstruction slows down your system despite
86  * idle IO detection.
87  *
88  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
89  * or /sys/block/mdX/md/sync_speed_{min,max}
90  */
91
92 static int sysctl_speed_limit_min = 1000;
93 static int sysctl_speed_limit_max = 200000;
94 static inline int speed_min(mddev_t *mddev)
95 {
96         return mddev->sync_speed_min ?
97                 mddev->sync_speed_min : sysctl_speed_limit_min;
98 }
99
100 static inline int speed_max(mddev_t *mddev)
101 {
102         return mddev->sync_speed_max ?
103                 mddev->sync_speed_max : sysctl_speed_limit_max;
104 }
105
106 static struct ctl_table_header *raid_table_header;
107
108 static ctl_table raid_table[] = {
109         {
110                 .ctl_name       = DEV_RAID_SPEED_LIMIT_MIN,
111                 .procname       = "speed_limit_min",
112                 .data           = &sysctl_speed_limit_min,
113                 .maxlen         = sizeof(int),
114                 .mode           = S_IRUGO|S_IWUSR,
115                 .proc_handler   = &proc_dointvec,
116         },
117         {
118                 .ctl_name       = DEV_RAID_SPEED_LIMIT_MAX,
119                 .procname       = "speed_limit_max",
120                 .data           = &sysctl_speed_limit_max,
121                 .maxlen         = sizeof(int),
122                 .mode           = S_IRUGO|S_IWUSR,
123                 .proc_handler   = &proc_dointvec,
124         },
125         { .ctl_name = 0 }
126 };
127
128 static ctl_table raid_dir_table[] = {
129         {
130                 .ctl_name       = DEV_RAID,
131                 .procname       = "raid",
132                 .maxlen         = 0,
133                 .mode           = S_IRUGO|S_IXUGO,
134                 .child          = raid_table,
135         },
136         { .ctl_name = 0 }
137 };
138
139 static ctl_table raid_root_table[] = {
140         {
141                 .ctl_name       = CTL_DEV,
142                 .procname       = "dev",
143                 .maxlen         = 0,
144                 .mode           = 0555,
145                 .child          = raid_dir_table,
146         },
147         { .ctl_name = 0 }
148 };
149
150 static struct block_device_operations md_fops;
151
152 static int start_readonly;
153
154 /*
155  * We have a system wide 'event count' that is incremented
156  * on any 'interesting' event, and readers of /proc/mdstat
157  * can use 'poll' or 'select' to find out when the event
158  * count increases.
159  *
160  * Events are:
161  *  start array, stop array, error, add device, remove device,
162  *  start build, activate spare
163  */
164 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
165 static atomic_t md_event_count;
166 void md_new_event(mddev_t *mddev)
167 {
168         atomic_inc(&md_event_count);
169         wake_up(&md_event_waiters);
170         sysfs_notify(&mddev->kobj, NULL, "sync_action");
171 }
172 EXPORT_SYMBOL_GPL(md_new_event);
173
174 /* Alternate version that can be called from interrupts
175  * when calling sysfs_notify isn't needed.
176  */
177 static void md_new_event_inintr(mddev_t *mddev)
178 {
179         atomic_inc(&md_event_count);
180         wake_up(&md_event_waiters);
181 }
182
183 /*
184  * Enables to iterate over all existing md arrays
185  * all_mddevs_lock protects this list.
186  */
187 static LIST_HEAD(all_mddevs);
188 static DEFINE_SPINLOCK(all_mddevs_lock);
189
190
191 /*
192  * iterates through all used mddevs in the system.
193  * We take care to grab the all_mddevs_lock whenever navigating
194  * the list, and to always hold a refcount when unlocked.
195  * Any code which breaks out of this loop while own
196  * a reference to the current mddev and must mddev_put it.
197  */
198 #define ITERATE_MDDEV(mddev,tmp)                                        \
199                                                                         \
200         for (({ spin_lock(&all_mddevs_lock);                            \
201                 tmp = all_mddevs.next;                                  \
202                 mddev = NULL;});                                        \
203              ({ if (tmp != &all_mddevs)                                 \
204                         mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
205                 spin_unlock(&all_mddevs_lock);                          \
206                 if (mddev) mddev_put(mddev);                            \
207                 mddev = list_entry(tmp, mddev_t, all_mddevs);           \
208                 tmp != &all_mddevs;});                                  \
209              ({ spin_lock(&all_mddevs_lock);                            \
210                 tmp = tmp->next;})                                      \
211                 )
212
213
214 static int md_fail_request (request_queue_t *q, struct bio *bio)
215 {
216         bio_io_error(bio, bio->bi_size);
217         return 0;
218 }
219
220 static inline mddev_t *mddev_get(mddev_t *mddev)
221 {
222         atomic_inc(&mddev->active);
223         return mddev;
224 }
225
226 static void mddev_put(mddev_t *mddev)
227 {
228         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
229                 return;
230         if (!mddev->raid_disks && list_empty(&mddev->disks)) {
231                 list_del(&mddev->all_mddevs);
232                 spin_unlock(&all_mddevs_lock);
233                 blk_cleanup_queue(mddev->queue);
234                 kobject_unregister(&mddev->kobj);
235         } else
236                 spin_unlock(&all_mddevs_lock);
237 }
238
239 static mddev_t * mddev_find(dev_t unit)
240 {
241         mddev_t *mddev, *new = NULL;
242
243  retry:
244         spin_lock(&all_mddevs_lock);
245         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
246                 if (mddev->unit == unit) {
247                         mddev_get(mddev);
248                         spin_unlock(&all_mddevs_lock);
249                         kfree(new);
250                         return mddev;
251                 }
252
253         if (new) {
254                 list_add(&new->all_mddevs, &all_mddevs);
255                 spin_unlock(&all_mddevs_lock);
256                 return new;
257         }
258         spin_unlock(&all_mddevs_lock);
259
260         new = kzalloc(sizeof(*new), GFP_KERNEL);
261         if (!new)
262                 return NULL;
263
264         new->unit = unit;
265         if (MAJOR(unit) == MD_MAJOR)
266                 new->md_minor = MINOR(unit);
267         else
268                 new->md_minor = MINOR(unit) >> MdpMinorShift;
269
270         mutex_init(&new->reconfig_mutex);
271         INIT_LIST_HEAD(&new->disks);
272         INIT_LIST_HEAD(&new->all_mddevs);
273         init_timer(&new->safemode_timer);
274         atomic_set(&new->active, 1);
275         spin_lock_init(&new->write_lock);
276         init_waitqueue_head(&new->sb_wait);
277         new->reshape_position = MaxSector;
278
279         new->queue = blk_alloc_queue(GFP_KERNEL);
280         if (!new->queue) {
281                 kfree(new);
282                 return NULL;
283         }
284         set_bit(QUEUE_FLAG_CLUSTER, &new->queue->queue_flags);
285
286         blk_queue_make_request(new->queue, md_fail_request);
287
288         goto retry;
289 }
290
291 static inline int mddev_lock(mddev_t * mddev)
292 {
293         return mutex_lock_interruptible(&mddev->reconfig_mutex);
294 }
295
296 static inline int mddev_trylock(mddev_t * mddev)
297 {
298         return mutex_trylock(&mddev->reconfig_mutex);
299 }
300
301 static inline void mddev_unlock(mddev_t * mddev)
302 {
303         mutex_unlock(&mddev->reconfig_mutex);
304
305         md_wakeup_thread(mddev->thread);
306 }
307
308 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
309 {
310         mdk_rdev_t * rdev;
311         struct list_head *tmp;
312
313         ITERATE_RDEV(mddev,rdev,tmp) {
314                 if (rdev->desc_nr == nr)
315                         return rdev;
316         }
317         return NULL;
318 }
319
320 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
321 {
322         struct list_head *tmp;
323         mdk_rdev_t *rdev;
324
325         ITERATE_RDEV(mddev,rdev,tmp) {
326                 if (rdev->bdev->bd_dev == dev)
327                         return rdev;
328         }
329         return NULL;
330 }
331
332 static struct mdk_personality *find_pers(int level, char *clevel)
333 {
334         struct mdk_personality *pers;
335         list_for_each_entry(pers, &pers_list, list) {
336                 if (level != LEVEL_NONE && pers->level == level)
337                         return pers;
338                 if (strcmp(pers->name, clevel)==0)
339                         return pers;
340         }
341         return NULL;
342 }
343
344 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
345 {
346         sector_t size = bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
347         return MD_NEW_SIZE_BLOCKS(size);
348 }
349
350 static sector_t calc_dev_size(mdk_rdev_t *rdev, unsigned chunk_size)
351 {
352         sector_t size;
353
354         size = rdev->sb_offset;
355
356         if (chunk_size)
357                 size &= ~((sector_t)chunk_size/1024 - 1);
358         return size;
359 }
360
361 static int alloc_disk_sb(mdk_rdev_t * rdev)
362 {
363         if (rdev->sb_page)
364                 MD_BUG();
365
366         rdev->sb_page = alloc_page(GFP_KERNEL);
367         if (!rdev->sb_page) {
368                 printk(KERN_ALERT "md: out of memory.\n");
369                 return -EINVAL;
370         }
371
372         return 0;
373 }
374
375 static void free_disk_sb(mdk_rdev_t * rdev)
376 {
377         if (rdev->sb_page) {
378                 put_page(rdev->sb_page);
379                 rdev->sb_loaded = 0;
380                 rdev->sb_page = NULL;
381                 rdev->sb_offset = 0;
382                 rdev->size = 0;
383         }
384 }
385
386
387 static int super_written(struct bio *bio, unsigned int bytes_done, int error)
388 {
389         mdk_rdev_t *rdev = bio->bi_private;
390         mddev_t *mddev = rdev->mddev;
391         if (bio->bi_size)
392                 return 1;
393
394         if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
395                 printk("md: super_written gets error=%d, uptodate=%d\n",
396                        error, test_bit(BIO_UPTODATE, &bio->bi_flags));
397                 WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
398                 md_error(mddev, rdev);
399         }
400
401         if (atomic_dec_and_test(&mddev->pending_writes))
402                 wake_up(&mddev->sb_wait);
403         bio_put(bio);
404         return 0;
405 }
406
407 static int super_written_barrier(struct bio *bio, unsigned int bytes_done, int error)
408 {
409         struct bio *bio2 = bio->bi_private;
410         mdk_rdev_t *rdev = bio2->bi_private;
411         mddev_t *mddev = rdev->mddev;
412         if (bio->bi_size)
413                 return 1;
414
415         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
416             error == -EOPNOTSUPP) {
417                 unsigned long flags;
418                 /* barriers don't appear to be supported :-( */
419                 set_bit(BarriersNotsupp, &rdev->flags);
420                 mddev->barriers_work = 0;
421                 spin_lock_irqsave(&mddev->write_lock, flags);
422                 bio2->bi_next = mddev->biolist;
423                 mddev->biolist = bio2;
424                 spin_unlock_irqrestore(&mddev->write_lock, flags);
425                 wake_up(&mddev->sb_wait);
426                 bio_put(bio);
427                 return 0;
428         }
429         bio_put(bio2);
430         bio->bi_private = rdev;
431         return super_written(bio, bytes_done, error);
432 }
433
434 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
435                    sector_t sector, int size, struct page *page)
436 {
437         /* write first size bytes of page to sector of rdev
438          * Increment mddev->pending_writes before returning
439          * and decrement it on completion, waking up sb_wait
440          * if zero is reached.
441          * If an error occurred, call md_error
442          *
443          * As we might need to resubmit the request if BIO_RW_BARRIER
444          * causes ENOTSUPP, we allocate a spare bio...
445          */
446         struct bio *bio = bio_alloc(GFP_NOIO, 1);
447         int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNC);
448
449         bio->bi_bdev = rdev->bdev;
450         bio->bi_sector = sector;
451         bio_add_page(bio, page, size, 0);
452         bio->bi_private = rdev;
453         bio->bi_end_io = super_written;
454         bio->bi_rw = rw;
455
456         atomic_inc(&mddev->pending_writes);
457         if (!test_bit(BarriersNotsupp, &rdev->flags)) {
458                 struct bio *rbio;
459                 rw |= (1<<BIO_RW_BARRIER);
460                 rbio = bio_clone(bio, GFP_NOIO);
461                 rbio->bi_private = bio;
462                 rbio->bi_end_io = super_written_barrier;
463                 submit_bio(rw, rbio);
464         } else
465                 submit_bio(rw, bio);
466 }
467
468 void md_super_wait(mddev_t *mddev)
469 {
470         /* wait for all superblock writes that were scheduled to complete.
471          * if any had to be retried (due to BARRIER problems), retry them
472          */
473         DEFINE_WAIT(wq);
474         for(;;) {
475                 prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
476                 if (atomic_read(&mddev->pending_writes)==0)
477                         break;
478                 while (mddev->biolist) {
479                         struct bio *bio;
480                         spin_lock_irq(&mddev->write_lock);
481                         bio = mddev->biolist;
482                         mddev->biolist = bio->bi_next ;
483                         bio->bi_next = NULL;
484                         spin_unlock_irq(&mddev->write_lock);
485                         submit_bio(bio->bi_rw, bio);
486                 }
487                 schedule();
488         }
489         finish_wait(&mddev->sb_wait, &wq);
490 }
491
492 static int bi_complete(struct bio *bio, unsigned int bytes_done, int error)
493 {
494         if (bio->bi_size)
495                 return 1;
496
497         complete((struct completion*)bio->bi_private);
498         return 0;
499 }
500
501 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
502                    struct page *page, int rw)
503 {
504         struct bio *bio = bio_alloc(GFP_NOIO, 1);
505         struct completion event;
506         int ret;
507
508         rw |= (1 << BIO_RW_SYNC);
509
510         bio->bi_bdev = bdev;
511         bio->bi_sector = sector;
512         bio_add_page(bio, page, size, 0);
513         init_completion(&event);
514         bio->bi_private = &event;
515         bio->bi_end_io = bi_complete;
516         submit_bio(rw, bio);
517         wait_for_completion(&event);
518
519         ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
520         bio_put(bio);
521         return ret;
522 }
523 EXPORT_SYMBOL_GPL(sync_page_io);
524
525 static int read_disk_sb(mdk_rdev_t * rdev, int size)
526 {
527         char b[BDEVNAME_SIZE];
528         if (!rdev->sb_page) {
529                 MD_BUG();
530                 return -EINVAL;
531         }
532         if (rdev->sb_loaded)
533                 return 0;
534
535
536         if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, size, rdev->sb_page, READ))
537                 goto fail;
538         rdev->sb_loaded = 1;
539         return 0;
540
541 fail:
542         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
543                 bdevname(rdev->bdev,b));
544         return -EINVAL;
545 }
546
547 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
548 {
549         if (    (sb1->set_uuid0 == sb2->set_uuid0) &&
550                 (sb1->set_uuid1 == sb2->set_uuid1) &&
551                 (sb1->set_uuid2 == sb2->set_uuid2) &&
552                 (sb1->set_uuid3 == sb2->set_uuid3))
553
554                 return 1;
555
556         return 0;
557 }
558
559
560 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
561 {
562         int ret;
563         mdp_super_t *tmp1, *tmp2;
564
565         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
566         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
567
568         if (!tmp1 || !tmp2) {
569                 ret = 0;
570                 printk(KERN_INFO "md.c: sb1 is not equal to sb2!\n");
571                 goto abort;
572         }
573
574         *tmp1 = *sb1;
575         *tmp2 = *sb2;
576
577         /*
578          * nr_disks is not constant
579          */
580         tmp1->nr_disks = 0;
581         tmp2->nr_disks = 0;
582
583         if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
584                 ret = 0;
585         else
586                 ret = 1;
587
588 abort:
589         kfree(tmp1);
590         kfree(tmp2);
591         return ret;
592 }
593
594
595 static u32 md_csum_fold(u32 csum)
596 {
597         csum = (csum & 0xffff) + (csum >> 16);
598         return (csum & 0xffff) + (csum >> 16);
599 }
600
601 static unsigned int calc_sb_csum(mdp_super_t * sb)
602 {
603         u64 newcsum = 0;
604         u32 *sb32 = (u32*)sb;
605         int i;
606         unsigned int disk_csum, csum;
607
608         disk_csum = sb->sb_csum;
609         sb->sb_csum = 0;
610
611         for (i = 0; i < MD_SB_BYTES/4 ; i++)
612                 newcsum += sb32[i];
613         csum = (newcsum & 0xffffffff) + (newcsum>>32);
614
615
616 #ifdef CONFIG_ALPHA
617         /* This used to use csum_partial, which was wrong for several
618          * reasons including that different results are returned on
619          * different architectures.  It isn't critical that we get exactly
620          * the same return value as before (we always csum_fold before
621          * testing, and that removes any differences).  However as we
622          * know that csum_partial always returned a 16bit value on
623          * alphas, do a fold to maximise conformity to previous behaviour.
624          */
625         sb->sb_csum = md_csum_fold(disk_csum);
626 #else
627         sb->sb_csum = disk_csum;
628 #endif
629         return csum;
630 }
631
632
633 /*
634  * Handle superblock details.
635  * We want to be able to handle multiple superblock formats
636  * so we have a common interface to them all, and an array of
637  * different handlers.
638  * We rely on user-space to write the initial superblock, and support
639  * reading and updating of superblocks.
640  * Interface methods are:
641  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
642  *      loads and validates a superblock on dev.
643  *      if refdev != NULL, compare superblocks on both devices
644  *    Return:
645  *      0 - dev has a superblock that is compatible with refdev
646  *      1 - dev has a superblock that is compatible and newer than refdev
647  *          so dev should be used as the refdev in future
648  *     -EINVAL superblock incompatible or invalid
649  *     -othererror e.g. -EIO
650  *
651  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
652  *      Verify that dev is acceptable into mddev.
653  *       The first time, mddev->raid_disks will be 0, and data from
654  *       dev should be merged in.  Subsequent calls check that dev
655  *       is new enough.  Return 0 or -EINVAL
656  *
657  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
658  *     Update the superblock for rdev with data in mddev
659  *     This does not write to disc.
660  *
661  */
662
663 struct super_type  {
664         char            *name;
665         struct module   *owner;
666         int             (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version);
667         int             (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
668         void            (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
669 };
670
671 /*
672  * load_super for 0.90.0 
673  */
674 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
675 {
676         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
677         mdp_super_t *sb;
678         int ret;
679         sector_t sb_offset;
680
681         /*
682          * Calculate the position of the superblock,
683          * it's at the end of the disk.
684          *
685          * It also happens to be a multiple of 4Kb.
686          */
687         sb_offset = calc_dev_sboffset(rdev->bdev);
688         rdev->sb_offset = sb_offset;
689
690         ret = read_disk_sb(rdev, MD_SB_BYTES);
691         if (ret) return ret;
692
693         ret = -EINVAL;
694
695         bdevname(rdev->bdev, b);
696         sb = (mdp_super_t*)page_address(rdev->sb_page);
697
698         if (sb->md_magic != MD_SB_MAGIC) {
699                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
700                        b);
701                 goto abort;
702         }
703
704         if (sb->major_version != 0 ||
705             sb->minor_version < 90 ||
706             sb->minor_version > 91) {
707                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
708                         sb->major_version, sb->minor_version,
709                         b);
710                 goto abort;
711         }
712
713         if (sb->raid_disks <= 0)
714                 goto abort;
715
716         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
717                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
718                         b);
719                 goto abort;
720         }
721
722         rdev->preferred_minor = sb->md_minor;
723         rdev->data_offset = 0;
724         rdev->sb_size = MD_SB_BYTES;
725
726         if (sb->state & (1<<MD_SB_BITMAP_PRESENT)) {
727                 if (sb->level != 1 && sb->level != 4
728                     && sb->level != 5 && sb->level != 6
729                     && sb->level != 10) {
730                         /* FIXME use a better test */
731                         printk(KERN_WARNING
732                                "md: bitmaps not supported for this level.\n");
733                         goto abort;
734                 }
735         }
736
737         if (sb->level == LEVEL_MULTIPATH)
738                 rdev->desc_nr = -1;
739         else
740                 rdev->desc_nr = sb->this_disk.number;
741
742         if (refdev == 0)
743                 ret = 1;
744         else {
745                 __u64 ev1, ev2;
746                 mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
747                 if (!uuid_equal(refsb, sb)) {
748                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
749                                 b, bdevname(refdev->bdev,b2));
750                         goto abort;
751                 }
752                 if (!sb_equal(refsb, sb)) {
753                         printk(KERN_WARNING "md: %s has same UUID"
754                                " but different superblock to %s\n",
755                                b, bdevname(refdev->bdev, b2));
756                         goto abort;
757                 }
758                 ev1 = md_event(sb);
759                 ev2 = md_event(refsb);
760                 if (ev1 > ev2)
761                         ret = 1;
762                 else 
763                         ret = 0;
764         }
765         rdev->size = calc_dev_size(rdev, sb->chunk_size);
766
767         if (rdev->size < sb->size && sb->level > 1)
768                 /* "this cannot possibly happen" ... */
769                 ret = -EINVAL;
770
771  abort:
772         return ret;
773 }
774
775 /*
776  * validate_super for 0.90.0
777  */
778 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
779 {
780         mdp_disk_t *desc;
781         mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
782         __u64 ev1 = md_event(sb);
783
784         rdev->raid_disk = -1;
785         rdev->flags = 0;
786         if (mddev->raid_disks == 0) {
787                 mddev->major_version = 0;
788                 mddev->minor_version = sb->minor_version;
789                 mddev->patch_version = sb->patch_version;
790                 mddev->persistent = ! sb->not_persistent;
791                 mddev->chunk_size = sb->chunk_size;
792                 mddev->ctime = sb->ctime;
793                 mddev->utime = sb->utime;
794                 mddev->level = sb->level;
795                 mddev->clevel[0] = 0;
796                 mddev->layout = sb->layout;
797                 mddev->raid_disks = sb->raid_disks;
798                 mddev->size = sb->size;
799                 mddev->events = ev1;
800                 mddev->bitmap_offset = 0;
801                 mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
802
803                 if (mddev->minor_version >= 91) {
804                         mddev->reshape_position = sb->reshape_position;
805                         mddev->delta_disks = sb->delta_disks;
806                         mddev->new_level = sb->new_level;
807                         mddev->new_layout = sb->new_layout;
808                         mddev->new_chunk = sb->new_chunk;
809                 } else {
810                         mddev->reshape_position = MaxSector;
811                         mddev->delta_disks = 0;
812                         mddev->new_level = mddev->level;
813                         mddev->new_layout = mddev->layout;
814                         mddev->new_chunk = mddev->chunk_size;
815                 }
816
817                 if (sb->state & (1<<MD_SB_CLEAN))
818                         mddev->recovery_cp = MaxSector;
819                 else {
820                         if (sb->events_hi == sb->cp_events_hi && 
821                                 sb->events_lo == sb->cp_events_lo) {
822                                 mddev->recovery_cp = sb->recovery_cp;
823                         } else
824                                 mddev->recovery_cp = 0;
825                 }
826
827                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
828                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
829                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
830                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
831
832                 mddev->max_disks = MD_SB_DISKS;
833
834                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
835                     mddev->bitmap_file == NULL)
836                         mddev->bitmap_offset = mddev->default_bitmap_offset;
837
838         } else if (mddev->pers == NULL) {
839                 /* Insist on good event counter while assembling */
840                 ++ev1;
841                 if (ev1 < mddev->events) 
842                         return -EINVAL;
843         } else if (mddev->bitmap) {
844                 /* if adding to array with a bitmap, then we can accept an
845                  * older device ... but not too old.
846                  */
847                 if (ev1 < mddev->bitmap->events_cleared)
848                         return 0;
849         } else {
850                 if (ev1 < mddev->events)
851                         /* just a hot-add of a new device, leave raid_disk at -1 */
852                         return 0;
853         }
854
855         if (mddev->level != LEVEL_MULTIPATH) {
856                 desc = sb->disks + rdev->desc_nr;
857
858                 if (desc->state & (1<<MD_DISK_FAULTY))
859                         set_bit(Faulty, &rdev->flags);
860                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
861                             desc->raid_disk < mddev->raid_disks */) {
862                         set_bit(In_sync, &rdev->flags);
863                         rdev->raid_disk = desc->raid_disk;
864                 }
865                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
866                         set_bit(WriteMostly, &rdev->flags);
867         } else /* MULTIPATH are always insync */
868                 set_bit(In_sync, &rdev->flags);
869         return 0;
870 }
871
872 /*
873  * sync_super for 0.90.0
874  */
875 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
876 {
877         mdp_super_t *sb;
878         struct list_head *tmp;
879         mdk_rdev_t *rdev2;
880         int next_spare = mddev->raid_disks;
881
882
883         /* make rdev->sb match mddev data..
884          *
885          * 1/ zero out disks
886          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
887          * 3/ any empty disks < next_spare become removed
888          *
889          * disks[0] gets initialised to REMOVED because
890          * we cannot be sure from other fields if it has
891          * been initialised or not.
892          */
893         int i;
894         int active=0, working=0,failed=0,spare=0,nr_disks=0;
895
896         rdev->sb_size = MD_SB_BYTES;
897
898         sb = (mdp_super_t*)page_address(rdev->sb_page);
899
900         memset(sb, 0, sizeof(*sb));
901
902         sb->md_magic = MD_SB_MAGIC;
903         sb->major_version = mddev->major_version;
904         sb->patch_version = mddev->patch_version;
905         sb->gvalid_words  = 0; /* ignored */
906         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
907         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
908         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
909         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
910
911         sb->ctime = mddev->ctime;
912         sb->level = mddev->level;
913         sb->size  = mddev->size;
914         sb->raid_disks = mddev->raid_disks;
915         sb->md_minor = mddev->md_minor;
916         sb->not_persistent = !mddev->persistent;
917         sb->utime = mddev->utime;
918         sb->state = 0;
919         sb->events_hi = (mddev->events>>32);
920         sb->events_lo = (u32)mddev->events;
921
922         if (mddev->reshape_position == MaxSector)
923                 sb->minor_version = 90;
924         else {
925                 sb->minor_version = 91;
926                 sb->reshape_position = mddev->reshape_position;
927                 sb->new_level = mddev->new_level;
928                 sb->delta_disks = mddev->delta_disks;
929                 sb->new_layout = mddev->new_layout;
930                 sb->new_chunk = mddev->new_chunk;
931         }
932         mddev->minor_version = sb->minor_version;
933         if (mddev->in_sync)
934         {
935                 sb->recovery_cp = mddev->recovery_cp;
936                 sb->cp_events_hi = (mddev->events>>32);
937                 sb->cp_events_lo = (u32)mddev->events;
938                 if (mddev->recovery_cp == MaxSector)
939                         sb->state = (1<< MD_SB_CLEAN);
940         } else
941                 sb->recovery_cp = 0;
942
943         sb->layout = mddev->layout;
944         sb->chunk_size = mddev->chunk_size;
945
946         if (mddev->bitmap && mddev->bitmap_file == NULL)
947                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
948
949         sb->disks[0].state = (1<<MD_DISK_REMOVED);
950         ITERATE_RDEV(mddev,rdev2,tmp) {
951                 mdp_disk_t *d;
952                 int desc_nr;
953                 if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
954                     && !test_bit(Faulty, &rdev2->flags))
955                         desc_nr = rdev2->raid_disk;
956                 else
957                         desc_nr = next_spare++;
958                 rdev2->desc_nr = desc_nr;
959                 d = &sb->disks[rdev2->desc_nr];
960                 nr_disks++;
961                 d->number = rdev2->desc_nr;
962                 d->major = MAJOR(rdev2->bdev->bd_dev);
963                 d->minor = MINOR(rdev2->bdev->bd_dev);
964                 if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
965                     && !test_bit(Faulty, &rdev2->flags))
966                         d->raid_disk = rdev2->raid_disk;
967                 else
968                         d->raid_disk = rdev2->desc_nr; /* compatibility */
969                 if (test_bit(Faulty, &rdev2->flags))
970                         d->state = (1<<MD_DISK_FAULTY);
971                 else if (test_bit(In_sync, &rdev2->flags)) {
972                         d->state = (1<<MD_DISK_ACTIVE);
973                         d->state |= (1<<MD_DISK_SYNC);
974                         active++;
975                         working++;
976                 } else {
977                         d->state = 0;
978                         spare++;
979                         working++;
980                 }
981                 if (test_bit(WriteMostly, &rdev2->flags))
982                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
983         }
984         /* now set the "removed" and "faulty" bits on any missing devices */
985         for (i=0 ; i < mddev->raid_disks ; i++) {
986                 mdp_disk_t *d = &sb->disks[i];
987                 if (d->state == 0 && d->number == 0) {
988                         d->number = i;
989                         d->raid_disk = i;
990                         d->state = (1<<MD_DISK_REMOVED);
991                         d->state |= (1<<MD_DISK_FAULTY);
992                         failed++;
993                 }
994         }
995         sb->nr_disks = nr_disks;
996         sb->active_disks = active;
997         sb->working_disks = working;
998         sb->failed_disks = failed;
999         sb->spare_disks = spare;
1000
1001         sb->this_disk = sb->disks[rdev->desc_nr];
1002         sb->sb_csum = calc_sb_csum(sb);
1003 }
1004
1005 /*
1006  * version 1 superblock
1007  */
1008
1009 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1010 {
1011         __le32 disk_csum;
1012         u32 csum;
1013         unsigned long long newcsum;
1014         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1015         __le32 *isuper = (__le32*)sb;
1016         int i;
1017
1018         disk_csum = sb->sb_csum;
1019         sb->sb_csum = 0;
1020         newcsum = 0;
1021         for (i=0; size>=4; size -= 4 )
1022                 newcsum += le32_to_cpu(*isuper++);
1023
1024         if (size == 2)
1025                 newcsum += le16_to_cpu(*(__le16*) isuper);
1026
1027         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1028         sb->sb_csum = disk_csum;
1029         return cpu_to_le32(csum);
1030 }
1031
1032 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1033 {
1034         struct mdp_superblock_1 *sb;
1035         int ret;
1036         sector_t sb_offset;
1037         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1038         int bmask;
1039
1040         /*
1041          * Calculate the position of the superblock.
1042          * It is always aligned to a 4K boundary and
1043          * depeding on minor_version, it can be:
1044          * 0: At least 8K, but less than 12K, from end of device
1045          * 1: At start of device
1046          * 2: 4K from start of device.
1047          */
1048         switch(minor_version) {
1049         case 0:
1050                 sb_offset = rdev->bdev->bd_inode->i_size >> 9;
1051                 sb_offset -= 8*2;
1052                 sb_offset &= ~(sector_t)(4*2-1);
1053                 /* convert from sectors to K */
1054                 sb_offset /= 2;
1055                 break;
1056         case 1:
1057                 sb_offset = 0;
1058                 break;
1059         case 2:
1060                 sb_offset = 4;
1061                 break;
1062         default:
1063                 return -EINVAL;
1064         }
1065         rdev->sb_offset = sb_offset;
1066
1067         /* superblock is rarely larger than 1K, but it can be larger,
1068          * and it is safe to read 4k, so we do that
1069          */
1070         ret = read_disk_sb(rdev, 4096);
1071         if (ret) return ret;
1072
1073
1074         sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1075
1076         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1077             sb->major_version != cpu_to_le32(1) ||
1078             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1079             le64_to_cpu(sb->super_offset) != (rdev->sb_offset<<1) ||
1080             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1081                 return -EINVAL;
1082
1083         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1084                 printk("md: invalid superblock checksum on %s\n",
1085                         bdevname(rdev->bdev,b));
1086                 return -EINVAL;
1087         }
1088         if (le64_to_cpu(sb->data_size) < 10) {
1089                 printk("md: data_size too small on %s\n",
1090                        bdevname(rdev->bdev,b));
1091                 return -EINVAL;
1092         }
1093         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET)) {
1094                 if (sb->level != cpu_to_le32(1) &&
1095                     sb->level != cpu_to_le32(4) &&
1096                     sb->level != cpu_to_le32(5) &&
1097                     sb->level != cpu_to_le32(6) &&
1098                     sb->level != cpu_to_le32(10)) {
1099                         printk(KERN_WARNING
1100                                "md: bitmaps not supported for this level.\n");
1101                         return -EINVAL;
1102                 }
1103         }
1104
1105         rdev->preferred_minor = 0xffff;
1106         rdev->data_offset = le64_to_cpu(sb->data_offset);
1107         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1108
1109         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1110         bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
1111         if (rdev->sb_size & bmask)
1112                 rdev-> sb_size = (rdev->sb_size | bmask)+1;
1113
1114         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1115                 rdev->desc_nr = -1;
1116         else
1117                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1118
1119         if (refdev == 0)
1120                 ret = 1;
1121         else {
1122                 __u64 ev1, ev2;
1123                 struct mdp_superblock_1 *refsb = 
1124                         (struct mdp_superblock_1*)page_address(refdev->sb_page);
1125
1126                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1127                     sb->level != refsb->level ||
1128                     sb->layout != refsb->layout ||
1129                     sb->chunksize != refsb->chunksize) {
1130                         printk(KERN_WARNING "md: %s has strangely different"
1131                                 " superblock to %s\n",
1132                                 bdevname(rdev->bdev,b),
1133                                 bdevname(refdev->bdev,b2));
1134                         return -EINVAL;
1135                 }
1136                 ev1 = le64_to_cpu(sb->events);
1137                 ev2 = le64_to_cpu(refsb->events);
1138
1139                 if (ev1 > ev2)
1140                         ret = 1;
1141                 else
1142                         ret = 0;
1143         }
1144         if (minor_version) 
1145                 rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
1146         else
1147                 rdev->size = rdev->sb_offset;
1148         if (rdev->size < le64_to_cpu(sb->data_size)/2)
1149                 return -EINVAL;
1150         rdev->size = le64_to_cpu(sb->data_size)/2;
1151         if (le32_to_cpu(sb->chunksize))
1152                 rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
1153
1154         if (le64_to_cpu(sb->size) > rdev->size*2)
1155                 return -EINVAL;
1156         return ret;
1157 }
1158
1159 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1160 {
1161         struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1162         __u64 ev1 = le64_to_cpu(sb->events);
1163
1164         rdev->raid_disk = -1;
1165         rdev->flags = 0;
1166         if (mddev->raid_disks == 0) {
1167                 mddev->major_version = 1;
1168                 mddev->patch_version = 0;
1169                 mddev->persistent = 1;
1170                 mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
1171                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1172                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1173                 mddev->level = le32_to_cpu(sb->level);
1174                 mddev->clevel[0] = 0;
1175                 mddev->layout = le32_to_cpu(sb->layout);
1176                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1177                 mddev->size = le64_to_cpu(sb->size)/2;
1178                 mddev->events = ev1;
1179                 mddev->bitmap_offset = 0;
1180                 mddev->default_bitmap_offset = 1024 >> 9;
1181                 
1182                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1183                 memcpy(mddev->uuid, sb->set_uuid, 16);
1184
1185                 mddev->max_disks =  (4096-256)/2;
1186
1187                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1188                     mddev->bitmap_file == NULL )
1189                         mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1190
1191                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1192                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1193                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1194                         mddev->new_level = le32_to_cpu(sb->new_level);
1195                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1196                         mddev->new_chunk = le32_to_cpu(sb->new_chunk)<<9;
1197                 } else {
1198                         mddev->reshape_position = MaxSector;
1199                         mddev->delta_disks = 0;
1200                         mddev->new_level = mddev->level;
1201                         mddev->new_layout = mddev->layout;
1202                         mddev->new_chunk = mddev->chunk_size;
1203                 }
1204
1205         } else if (mddev->pers == NULL) {
1206                 /* Insist of good event counter while assembling */
1207                 ++ev1;
1208                 if (ev1 < mddev->events)
1209                         return -EINVAL;
1210         } else if (mddev->bitmap) {
1211                 /* If adding to array with a bitmap, then we can accept an
1212                  * older device, but not too old.
1213                  */
1214                 if (ev1 < mddev->bitmap->events_cleared)
1215                         return 0;
1216         } else {
1217                 if (ev1 < mddev->events)
1218                         /* just a hot-add of a new device, leave raid_disk at -1 */
1219                         return 0;
1220         }
1221         if (mddev->level != LEVEL_MULTIPATH) {
1222                 int role;
1223                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1224                 switch(role) {
1225                 case 0xffff: /* spare */
1226                         break;
1227                 case 0xfffe: /* faulty */
1228                         set_bit(Faulty, &rdev->flags);
1229                         break;
1230                 default:
1231                         if ((le32_to_cpu(sb->feature_map) &
1232                              MD_FEATURE_RECOVERY_OFFSET))
1233                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1234                         else
1235                                 set_bit(In_sync, &rdev->flags);
1236                         rdev->raid_disk = role;
1237                         break;
1238                 }
1239                 if (sb->devflags & WriteMostly1)
1240                         set_bit(WriteMostly, &rdev->flags);
1241         } else /* MULTIPATH are always insync */
1242                 set_bit(In_sync, &rdev->flags);
1243
1244         return 0;
1245 }
1246
1247 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1248 {
1249         struct mdp_superblock_1 *sb;
1250         struct list_head *tmp;
1251         mdk_rdev_t *rdev2;
1252         int max_dev, i;
1253         /* make rdev->sb match mddev and rdev data. */
1254
1255         sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1256
1257         sb->feature_map = 0;
1258         sb->pad0 = 0;
1259         sb->recovery_offset = cpu_to_le64(0);
1260         memset(sb->pad1, 0, sizeof(sb->pad1));
1261         memset(sb->pad2, 0, sizeof(sb->pad2));
1262         memset(sb->pad3, 0, sizeof(sb->pad3));
1263
1264         sb->utime = cpu_to_le64((__u64)mddev->utime);
1265         sb->events = cpu_to_le64(mddev->events);
1266         if (mddev->in_sync)
1267                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1268         else
1269                 sb->resync_offset = cpu_to_le64(0);
1270
1271         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1272
1273         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1274         sb->size = cpu_to_le64(mddev->size<<1);
1275
1276         if (mddev->bitmap && mddev->bitmap_file == NULL) {
1277                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1278                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1279         }
1280
1281         if (rdev->raid_disk >= 0 &&
1282             !test_bit(In_sync, &rdev->flags) &&
1283             rdev->recovery_offset > 0) {
1284                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1285                 sb->recovery_offset = cpu_to_le64(rdev->recovery_offset);
1286         }
1287
1288         if (mddev->reshape_position != MaxSector) {
1289                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1290                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1291                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1292                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1293                 sb->new_level = cpu_to_le32(mddev->new_level);
1294                 sb->new_chunk = cpu_to_le32(mddev->new_chunk>>9);
1295         }
1296
1297         max_dev = 0;
1298         ITERATE_RDEV(mddev,rdev2,tmp)
1299                 if (rdev2->desc_nr+1 > max_dev)
1300                         max_dev = rdev2->desc_nr+1;
1301
1302         if (max_dev > le32_to_cpu(sb->max_dev))
1303                 sb->max_dev = cpu_to_le32(max_dev);
1304         for (i=0; i<max_dev;i++)
1305                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
1306         
1307         ITERATE_RDEV(mddev,rdev2,tmp) {
1308                 i = rdev2->desc_nr;
1309                 if (test_bit(Faulty, &rdev2->flags))
1310                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
1311                 else if (test_bit(In_sync, &rdev2->flags))
1312                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1313                 else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
1314                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1315                 else
1316                         sb->dev_roles[i] = cpu_to_le16(0xffff);
1317         }
1318
1319         sb->sb_csum = calc_sb_1_csum(sb);
1320 }
1321
1322
1323 static struct super_type super_types[] = {
1324         [0] = {
1325                 .name   = "0.90.0",
1326                 .owner  = THIS_MODULE,
1327                 .load_super     = super_90_load,
1328                 .validate_super = super_90_validate,
1329                 .sync_super     = super_90_sync,
1330         },
1331         [1] = {
1332                 .name   = "md-1",
1333                 .owner  = THIS_MODULE,
1334                 .load_super     = super_1_load,
1335                 .validate_super = super_1_validate,
1336                 .sync_super     = super_1_sync,
1337         },
1338 };
1339
1340 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1341 {
1342         struct list_head *tmp, *tmp2;
1343         mdk_rdev_t *rdev, *rdev2;
1344
1345         ITERATE_RDEV(mddev1,rdev,tmp)
1346                 ITERATE_RDEV(mddev2, rdev2, tmp2)
1347                         if (rdev->bdev->bd_contains ==
1348                             rdev2->bdev->bd_contains)
1349                                 return 1;
1350
1351         return 0;
1352 }
1353
1354 static LIST_HEAD(pending_raid_disks);
1355
1356 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1357 {
1358         char b[BDEVNAME_SIZE];
1359         struct kobject *ko;
1360         char *s;
1361         int err;
1362
1363         if (rdev->mddev) {
1364                 MD_BUG();
1365                 return -EINVAL;
1366         }
1367         /* make sure rdev->size exceeds mddev->size */
1368         if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
1369                 if (mddev->pers) {
1370                         /* Cannot change size, so fail
1371                          * If mddev->level <= 0, then we don't care
1372                          * about aligning sizes (e.g. linear)
1373                          */
1374                         if (mddev->level > 0)
1375                                 return -ENOSPC;
1376                 } else
1377                         mddev->size = rdev->size;
1378         }
1379
1380         /* Verify rdev->desc_nr is unique.
1381          * If it is -1, assign a free number, else
1382          * check number is not in use
1383          */
1384         if (rdev->desc_nr < 0) {
1385                 int choice = 0;
1386                 if (mddev->pers) choice = mddev->raid_disks;
1387                 while (find_rdev_nr(mddev, choice))
1388                         choice++;
1389                 rdev->desc_nr = choice;
1390         } else {
1391                 if (find_rdev_nr(mddev, rdev->desc_nr))
1392                         return -EBUSY;
1393         }
1394         bdevname(rdev->bdev,b);
1395         if (kobject_set_name(&rdev->kobj, "dev-%s", b) < 0)
1396                 return -ENOMEM;
1397         while ( (s=strchr(rdev->kobj.k_name, '/')) != NULL)
1398                 *s = '!';
1399                         
1400         rdev->mddev = mddev;
1401         printk(KERN_INFO "md: bind<%s>\n", b);
1402
1403         rdev->kobj.parent = &mddev->kobj;
1404         if ((err = kobject_add(&rdev->kobj)))
1405                 goto fail;
1406
1407         if (rdev->bdev->bd_part)
1408                 ko = &rdev->bdev->bd_part->kobj;
1409         else
1410                 ko = &rdev->bdev->bd_disk->kobj;
1411         if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
1412                 kobject_del(&rdev->kobj);
1413                 goto fail;
1414         }
1415         list_add(&rdev->same_set, &mddev->disks);
1416         bd_claim_by_disk(rdev->bdev, rdev, mddev->gendisk);
1417         return 0;
1418
1419  fail:
1420         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1421                b, mdname(mddev));
1422         return err;
1423 }
1424
1425 static void delayed_delete(struct work_struct *ws)
1426 {
1427         mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1428         kobject_del(&rdev->kobj);
1429 }
1430
1431 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1432 {
1433         char b[BDEVNAME_SIZE];
1434         if (!rdev->mddev) {
1435                 MD_BUG();
1436                 return;
1437         }
1438         bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1439         list_del_init(&rdev->same_set);
1440         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1441         rdev->mddev = NULL;
1442         sysfs_remove_link(&rdev->kobj, "block");
1443
1444         /* We need to delay this, otherwise we can deadlock when
1445          * writing to 'remove' to "dev/state"
1446          */
1447         INIT_WORK(&rdev->del_work, delayed_delete);
1448         schedule_work(&rdev->del_work);
1449 }
1450
1451 /*
1452  * prevent the device from being mounted, repartitioned or
1453  * otherwise reused by a RAID array (or any other kernel
1454  * subsystem), by bd_claiming the device.
1455  */
1456 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev)
1457 {
1458         int err = 0;
1459         struct block_device *bdev;
1460         char b[BDEVNAME_SIZE];
1461
1462         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1463         if (IS_ERR(bdev)) {
1464                 printk(KERN_ERR "md: could not open %s.\n",
1465                         __bdevname(dev, b));
1466                 return PTR_ERR(bdev);
1467         }
1468         err = bd_claim(bdev, rdev);
1469         if (err) {
1470                 printk(KERN_ERR "md: could not bd_claim %s.\n",
1471                         bdevname(bdev, b));
1472                 blkdev_put(bdev);
1473                 return err;
1474         }
1475         rdev->bdev = bdev;
1476         return err;
1477 }
1478
1479 static void unlock_rdev(mdk_rdev_t *rdev)
1480 {
1481         struct block_device *bdev = rdev->bdev;
1482         rdev->bdev = NULL;
1483         if (!bdev)
1484                 MD_BUG();
1485         bd_release(bdev);
1486         blkdev_put(bdev);
1487 }
1488
1489 void md_autodetect_dev(dev_t dev);
1490
1491 static void export_rdev(mdk_rdev_t * rdev)
1492 {
1493         char b[BDEVNAME_SIZE];
1494         printk(KERN_INFO "md: export_rdev(%s)\n",
1495                 bdevname(rdev->bdev,b));
1496         if (rdev->mddev)
1497                 MD_BUG();
1498         free_disk_sb(rdev);
1499         list_del_init(&rdev->same_set);
1500 #ifndef MODULE
1501         md_autodetect_dev(rdev->bdev->bd_dev);
1502 #endif
1503         unlock_rdev(rdev);
1504         kobject_put(&rdev->kobj);
1505 }
1506
1507 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1508 {
1509         unbind_rdev_from_array(rdev);
1510         export_rdev(rdev);
1511 }
1512
1513 static void export_array(mddev_t *mddev)
1514 {
1515         struct list_head *tmp;
1516         mdk_rdev_t *rdev;
1517
1518         ITERATE_RDEV(mddev,rdev,tmp) {
1519                 if (!rdev->mddev) {
1520                         MD_BUG();
1521                         continue;
1522                 }
1523                 kick_rdev_from_array(rdev);
1524         }
1525         if (!list_empty(&mddev->disks))
1526                 MD_BUG();
1527         mddev->raid_disks = 0;
1528         mddev->major_version = 0;
1529 }
1530
1531 static void print_desc(mdp_disk_t *desc)
1532 {
1533         printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1534                 desc->major,desc->minor,desc->raid_disk,desc->state);
1535 }
1536
1537 static void print_sb(mdp_super_t *sb)
1538 {
1539         int i;
1540
1541         printk(KERN_INFO 
1542                 "md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1543                 sb->major_version, sb->minor_version, sb->patch_version,
1544                 sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1545                 sb->ctime);
1546         printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1547                 sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1548                 sb->md_minor, sb->layout, sb->chunk_size);
1549         printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1550                 " FD:%d SD:%d CSUM:%08x E:%08lx\n",
1551                 sb->utime, sb->state, sb->active_disks, sb->working_disks,
1552                 sb->failed_disks, sb->spare_disks,
1553                 sb->sb_csum, (unsigned long)sb->events_lo);
1554
1555         printk(KERN_INFO);
1556         for (i = 0; i < MD_SB_DISKS; i++) {
1557                 mdp_disk_t *desc;
1558
1559                 desc = sb->disks + i;
1560                 if (desc->number || desc->major || desc->minor ||
1561                     desc->raid_disk || (desc->state && (desc->state != 4))) {
1562                         printk("     D %2d: ", i);
1563                         print_desc(desc);
1564                 }
1565         }
1566         printk(KERN_INFO "md:     THIS: ");
1567         print_desc(&sb->this_disk);
1568
1569 }
1570
1571 static void print_rdev(mdk_rdev_t *rdev)
1572 {
1573         char b[BDEVNAME_SIZE];
1574         printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
1575                 bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
1576                 test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1577                 rdev->desc_nr);
1578         if (rdev->sb_loaded) {
1579                 printk(KERN_INFO "md: rdev superblock:\n");
1580                 print_sb((mdp_super_t*)page_address(rdev->sb_page));
1581         } else
1582                 printk(KERN_INFO "md: no rdev superblock!\n");
1583 }
1584
1585 static void md_print_devices(void)
1586 {
1587         struct list_head *tmp, *tmp2;
1588         mdk_rdev_t *rdev;
1589         mddev_t *mddev;
1590         char b[BDEVNAME_SIZE];
1591
1592         printk("\n");
1593         printk("md:     **********************************\n");
1594         printk("md:     * <COMPLETE RAID STATE PRINTOUT> *\n");
1595         printk("md:     **********************************\n");
1596         ITERATE_MDDEV(mddev,tmp) {
1597
1598                 if (mddev->bitmap)
1599                         bitmap_print_sb(mddev->bitmap);
1600                 else
1601                         printk("%s: ", mdname(mddev));
1602                 ITERATE_RDEV(mddev,rdev,tmp2)
1603                         printk("<%s>", bdevname(rdev->bdev,b));
1604                 printk("\n");
1605
1606                 ITERATE_RDEV(mddev,rdev,tmp2)
1607                         print_rdev(rdev);
1608         }
1609         printk("md:     **********************************\n");
1610         printk("\n");
1611 }
1612
1613
1614 static void sync_sbs(mddev_t * mddev, int nospares)
1615 {
1616         /* Update each superblock (in-memory image), but
1617          * if we are allowed to, skip spares which already
1618          * have the right event counter, or have one earlier
1619          * (which would mean they aren't being marked as dirty
1620          * with the rest of the array)
1621          */
1622         mdk_rdev_t *rdev;
1623         struct list_head *tmp;
1624
1625         ITERATE_RDEV(mddev,rdev,tmp) {
1626                 if (rdev->sb_events == mddev->events ||
1627                     (nospares &&
1628                      rdev->raid_disk < 0 &&
1629                      (rdev->sb_events&1)==0 &&
1630                      rdev->sb_events+1 == mddev->events)) {
1631                         /* Don't update this superblock */
1632                         rdev->sb_loaded = 2;
1633                 } else {
1634                         super_types[mddev->major_version].
1635                                 sync_super(mddev, rdev);
1636                         rdev->sb_loaded = 1;
1637                 }
1638         }
1639 }
1640
1641 static void md_update_sb(mddev_t * mddev, int force_change)
1642 {
1643         struct list_head *tmp;
1644         mdk_rdev_t *rdev;
1645         int sync_req;
1646         int nospares = 0;
1647
1648 repeat:
1649         spin_lock_irq(&mddev->write_lock);
1650
1651         set_bit(MD_CHANGE_PENDING, &mddev->flags);
1652         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
1653                 force_change = 1;
1654         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
1655                 /* just a clean<-> dirty transition, possibly leave spares alone,
1656                  * though if events isn't the right even/odd, we will have to do
1657                  * spares after all
1658                  */
1659                 nospares = 1;
1660         if (force_change)
1661                 nospares = 0;
1662         if (mddev->degraded)
1663                 /* If the array is degraded, then skipping spares is both
1664                  * dangerous and fairly pointless.
1665                  * Dangerous because a device that was removed from the array
1666                  * might have a event_count that still looks up-to-date,
1667                  * so it can be re-added without a resync.
1668                  * Pointless because if there are any spares to skip,
1669                  * then a recovery will happen and soon that array won't
1670                  * be degraded any more and the spare can go back to sleep then.
1671                  */
1672                 nospares = 0;
1673
1674         sync_req = mddev->in_sync;
1675         mddev->utime = get_seconds();
1676
1677         /* If this is just a dirty<->clean transition, and the array is clean
1678          * and 'events' is odd, we can roll back to the previous clean state */
1679         if (nospares
1680             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
1681             && (mddev->events & 1)
1682             && mddev->events != 1)
1683                 mddev->events--;
1684         else {
1685                 /* otherwise we have to go forward and ... */
1686                 mddev->events ++;
1687                 if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
1688                         /* .. if the array isn't clean, insist on an odd 'events' */
1689                         if ((mddev->events&1)==0) {
1690                                 mddev->events++;
1691                                 nospares = 0;
1692                         }
1693                 } else {
1694                         /* otherwise insist on an even 'events' (for clean states) */
1695                         if ((mddev->events&1)) {
1696                                 mddev->events++;
1697                                 nospares = 0;
1698                         }
1699                 }
1700         }
1701
1702         if (!mddev->events) {
1703                 /*
1704                  * oops, this 64-bit counter should never wrap.
1705                  * Either we are in around ~1 trillion A.C., assuming
1706                  * 1 reboot per second, or we have a bug:
1707                  */
1708                 MD_BUG();
1709                 mddev->events --;
1710         }
1711         sync_sbs(mddev, nospares);
1712
1713         /*
1714          * do not write anything to disk if using
1715          * nonpersistent superblocks
1716          */
1717         if (!mddev->persistent) {
1718                 clear_bit(MD_CHANGE_PENDING, &mddev->flags);
1719                 spin_unlock_irq(&mddev->write_lock);
1720                 wake_up(&mddev->sb_wait);
1721                 return;
1722         }
1723         spin_unlock_irq(&mddev->write_lock);
1724
1725         dprintk(KERN_INFO 
1726                 "md: updating %s RAID superblock on device (in sync %d)\n",
1727                 mdname(mddev),mddev->in_sync);
1728
1729         bitmap_update_sb(mddev->bitmap);
1730         ITERATE_RDEV(mddev,rdev,tmp) {
1731                 char b[BDEVNAME_SIZE];
1732                 dprintk(KERN_INFO "md: ");
1733                 if (rdev->sb_loaded != 1)
1734                         continue; /* no noise on spare devices */
1735                 if (test_bit(Faulty, &rdev->flags))
1736                         dprintk("(skipping faulty ");
1737
1738                 dprintk("%s ", bdevname(rdev->bdev,b));
1739                 if (!test_bit(Faulty, &rdev->flags)) {
1740                         md_super_write(mddev,rdev,
1741                                        rdev->sb_offset<<1, rdev->sb_size,
1742                                        rdev->sb_page);
1743                         dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1744                                 bdevname(rdev->bdev,b),
1745                                 (unsigned long long)rdev->sb_offset);
1746                         rdev->sb_events = mddev->events;
1747
1748                 } else
1749                         dprintk(")\n");
1750                 if (mddev->level == LEVEL_MULTIPATH)
1751                         /* only need to write one superblock... */
1752                         break;
1753         }
1754         md_super_wait(mddev);
1755         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
1756
1757         spin_lock_irq(&mddev->write_lock);
1758         if (mddev->in_sync != sync_req ||
1759             test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
1760                 /* have to write it out again */
1761                 spin_unlock_irq(&mddev->write_lock);
1762                 goto repeat;
1763         }
1764         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
1765         spin_unlock_irq(&mddev->write_lock);
1766         wake_up(&mddev->sb_wait);
1767
1768 }
1769
1770 /* words written to sysfs files may, or my not, be \n terminated.
1771  * We want to accept with case. For this we use cmd_match.
1772  */
1773 static int cmd_match(const char *cmd, const char *str)
1774 {
1775         /* See if cmd, written into a sysfs file, matches
1776          * str.  They must either be the same, or cmd can
1777          * have a trailing newline
1778          */
1779         while (*cmd && *str && *cmd == *str) {
1780                 cmd++;
1781                 str++;
1782         }
1783         if (*cmd == '\n')
1784                 cmd++;
1785         if (*str || *cmd)
1786                 return 0;
1787         return 1;
1788 }
1789
1790 struct rdev_sysfs_entry {
1791         struct attribute attr;
1792         ssize_t (*show)(mdk_rdev_t *, char *);
1793         ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
1794 };
1795
1796 static ssize_t
1797 state_show(mdk_rdev_t *rdev, char *page)
1798 {
1799         char *sep = "";
1800         int len=0;
1801
1802         if (test_bit(Faulty, &rdev->flags)) {
1803                 len+= sprintf(page+len, "%sfaulty",sep);
1804                 sep = ",";
1805         }
1806         if (test_bit(In_sync, &rdev->flags)) {
1807                 len += sprintf(page+len, "%sin_sync",sep);
1808                 sep = ",";
1809         }
1810         if (test_bit(WriteMostly, &rdev->flags)) {
1811                 len += sprintf(page+len, "%swrite_mostly",sep);
1812                 sep = ",";
1813         }
1814         if (!test_bit(Faulty, &rdev->flags) &&
1815             !test_bit(In_sync, &rdev->flags)) {
1816                 len += sprintf(page+len, "%sspare", sep);
1817                 sep = ",";
1818         }
1819         return len+sprintf(page+len, "\n");
1820 }
1821
1822 static ssize_t
1823 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1824 {
1825         /* can write
1826          *  faulty  - simulates and error
1827          *  remove  - disconnects the device
1828          *  writemostly - sets write_mostly
1829          *  -writemostly - clears write_mostly
1830          */
1831         int err = -EINVAL;
1832         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
1833                 md_error(rdev->mddev, rdev);
1834                 err = 0;
1835         } else if (cmd_match(buf, "remove")) {
1836                 if (rdev->raid_disk >= 0)
1837                         err = -EBUSY;
1838                 else {
1839                         mddev_t *mddev = rdev->mddev;
1840                         kick_rdev_from_array(rdev);
1841                         if (mddev->pers)
1842                                 md_update_sb(mddev, 1);
1843                         md_new_event(mddev);
1844                         err = 0;
1845                 }
1846         } else if (cmd_match(buf, "writemostly")) {
1847                 set_bit(WriteMostly, &rdev->flags);
1848                 err = 0;
1849         } else if (cmd_match(buf, "-writemostly")) {
1850                 clear_bit(WriteMostly, &rdev->flags);
1851                 err = 0;
1852         }
1853         return err ? err : len;
1854 }
1855 static struct rdev_sysfs_entry rdev_state =
1856 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
1857
1858 static ssize_t
1859 super_show(mdk_rdev_t *rdev, char *page)
1860 {
1861         if (rdev->sb_loaded && rdev->sb_size) {
1862                 memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
1863                 return rdev->sb_size;
1864         } else
1865                 return 0;
1866 }
1867 static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
1868
1869 static ssize_t
1870 errors_show(mdk_rdev_t *rdev, char *page)
1871 {
1872         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
1873 }
1874
1875 static ssize_t
1876 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1877 {
1878         char *e;
1879         unsigned long n = simple_strtoul(buf, &e, 10);
1880         if (*buf && (*e == 0 || *e == '\n')) {
1881                 atomic_set(&rdev->corrected_errors, n);
1882                 return len;
1883         }
1884         return -EINVAL;
1885 }
1886 static struct rdev_sysfs_entry rdev_errors =
1887 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
1888
1889 static ssize_t
1890 slot_show(mdk_rdev_t *rdev, char *page)
1891 {
1892         if (rdev->raid_disk < 0)
1893                 return sprintf(page, "none\n");
1894         else
1895                 return sprintf(page, "%d\n", rdev->raid_disk);
1896 }
1897
1898 static ssize_t
1899 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1900 {
1901         char *e;
1902         int slot = simple_strtoul(buf, &e, 10);
1903         if (strncmp(buf, "none", 4)==0)
1904                 slot = -1;
1905         else if (e==buf || (*e && *e!= '\n'))
1906                 return -EINVAL;
1907         if (rdev->mddev->pers)
1908                 /* Cannot set slot in active array (yet) */
1909                 return -EBUSY;
1910         if (slot >= rdev->mddev->raid_disks)
1911                 return -ENOSPC;
1912         rdev->raid_disk = slot;
1913         /* assume it is working */
1914         rdev->flags = 0;
1915         set_bit(In_sync, &rdev->flags);
1916         return len;
1917 }
1918
1919
1920 static struct rdev_sysfs_entry rdev_slot =
1921 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
1922
1923 static ssize_t
1924 offset_show(mdk_rdev_t *rdev, char *page)
1925 {
1926         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
1927 }
1928
1929 static ssize_t
1930 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1931 {
1932         char *e;
1933         unsigned long long offset = simple_strtoull(buf, &e, 10);
1934         if (e==buf || (*e && *e != '\n'))
1935                 return -EINVAL;
1936         if (rdev->mddev->pers)
1937                 return -EBUSY;
1938         rdev->data_offset = offset;
1939         return len;
1940 }
1941
1942 static struct rdev_sysfs_entry rdev_offset =
1943 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
1944
1945 static ssize_t
1946 rdev_size_show(mdk_rdev_t *rdev, char *page)
1947 {
1948         return sprintf(page, "%llu\n", (unsigned long long)rdev->size);
1949 }
1950
1951 static ssize_t
1952 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1953 {
1954         char *e;
1955         unsigned long long size = simple_strtoull(buf, &e, 10);
1956         if (e==buf || (*e && *e != '\n'))
1957                 return -EINVAL;
1958         if (rdev->mddev->pers)
1959                 return -EBUSY;
1960         rdev->size = size;
1961         if (size < rdev->mddev->size || rdev->mddev->size == 0)
1962                 rdev->mddev->size = size;
1963         return len;
1964 }
1965
1966 static struct rdev_sysfs_entry rdev_size =
1967 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
1968
1969 static struct attribute *rdev_default_attrs[] = {
1970         &rdev_state.attr,
1971         &rdev_super.attr,
1972         &rdev_errors.attr,
1973         &rdev_slot.attr,
1974         &rdev_offset.attr,
1975         &rdev_size.attr,
1976         NULL,
1977 };
1978 static ssize_t
1979 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
1980 {
1981         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1982         mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1983
1984         if (!entry->show)
1985                 return -EIO;
1986         return entry->show(rdev, page);
1987 }
1988
1989 static ssize_t
1990 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
1991               const char *page, size_t length)
1992 {
1993         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1994         mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1995
1996         if (!entry->store)
1997                 return -EIO;
1998         if (!capable(CAP_SYS_ADMIN))
1999                 return -EACCES;
2000         return entry->store(rdev, page, length);
2001 }
2002
2003 static void rdev_free(struct kobject *ko)
2004 {
2005         mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2006         kfree(rdev);
2007 }
2008 static struct sysfs_ops rdev_sysfs_ops = {
2009         .show           = rdev_attr_show,
2010         .store          = rdev_attr_store,
2011 };
2012 static struct kobj_type rdev_ktype = {
2013         .release        = rdev_free,
2014         .sysfs_ops      = &rdev_sysfs_ops,
2015         .default_attrs  = rdev_default_attrs,
2016 };
2017
2018 /*
2019  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2020  *
2021  * mark the device faulty if:
2022  *
2023  *   - the device is nonexistent (zero size)
2024  *   - the device has no valid superblock
2025  *
2026  * a faulty rdev _never_ has rdev->sb set.
2027  */
2028 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2029 {
2030         char b[BDEVNAME_SIZE];
2031         int err;
2032         mdk_rdev_t *rdev;
2033         sector_t size;
2034
2035         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2036         if (!rdev) {
2037                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
2038                 return ERR_PTR(-ENOMEM);
2039         }
2040
2041         if ((err = alloc_disk_sb(rdev)))
2042                 goto abort_free;
2043
2044         err = lock_rdev(rdev, newdev);
2045         if (err)
2046                 goto abort_free;
2047
2048         rdev->kobj.parent = NULL;
2049         rdev->kobj.ktype = &rdev_ktype;
2050         kobject_init(&rdev->kobj);
2051
2052         rdev->desc_nr = -1;
2053         rdev->saved_raid_disk = -1;
2054         rdev->raid_disk = -1;
2055         rdev->flags = 0;
2056         rdev->data_offset = 0;
2057         rdev->sb_events = 0;
2058         atomic_set(&rdev->nr_pending, 0);
2059         atomic_set(&rdev->read_errors, 0);
2060         atomic_set(&rdev->corrected_errors, 0);
2061
2062         size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2063         if (!size) {
2064                 printk(KERN_WARNING 
2065                         "md: %s has zero or unknown size, marking faulty!\n",
2066                         bdevname(rdev->bdev,b));
2067                 err = -EINVAL;
2068                 goto abort_free;
2069         }
2070
2071         if (super_format >= 0) {
2072                 err = super_types[super_format].
2073                         load_super(rdev, NULL, super_minor);
2074                 if (err == -EINVAL) {
2075                         printk(KERN_WARNING
2076                                 "md: %s does not have a valid v%d.%d "
2077                                "superblock, not importing!\n",
2078                                 bdevname(rdev->bdev,b),
2079                                super_format, super_minor);
2080                         goto abort_free;
2081                 }
2082                 if (err < 0) {
2083                         printk(KERN_WARNING 
2084                                 "md: could not read %s's sb, not importing!\n",
2085                                 bdevname(rdev->bdev,b));
2086                         goto abort_free;
2087                 }
2088         }
2089         INIT_LIST_HEAD(&rdev->same_set);
2090
2091         return rdev;
2092
2093 abort_free:
2094         if (rdev->sb_page) {
2095                 if (rdev->bdev)
2096                         unlock_rdev(rdev);
2097                 free_disk_sb(rdev);
2098         }
2099         kfree(rdev);
2100         return ERR_PTR(err);
2101 }
2102
2103 /*
2104  * Check a full RAID array for plausibility
2105  */
2106
2107
2108 static void analyze_sbs(mddev_t * mddev)
2109 {
2110         int i;
2111         struct list_head *tmp;
2112         mdk_rdev_t *rdev, *freshest;
2113         char b[BDEVNAME_SIZE];
2114
2115         freshest = NULL;
2116         ITERATE_RDEV(mddev,rdev,tmp)
2117                 switch (super_types[mddev->major_version].
2118                         load_super(rdev, freshest, mddev->minor_version)) {
2119                 case 1:
2120                         freshest = rdev;
2121                         break;
2122                 case 0:
2123                         break;
2124                 default:
2125                         printk( KERN_ERR \
2126                                 "md: fatal superblock inconsistency in %s"
2127                                 " -- removing from array\n", 
2128                                 bdevname(rdev->bdev,b));
2129                         kick_rdev_from_array(rdev);
2130                 }
2131
2132
2133         super_types[mddev->major_version].
2134                 validate_super(mddev, freshest);
2135
2136         i = 0;
2137         ITERATE_RDEV(mddev,rdev,tmp) {
2138                 if (rdev != freshest)
2139                         if (super_types[mddev->major_version].
2140                             validate_super(mddev, rdev)) {
2141                                 printk(KERN_WARNING "md: kicking non-fresh %s"
2142                                         " from array!\n",
2143                                         bdevname(rdev->bdev,b));
2144                                 kick_rdev_from_array(rdev);
2145                                 continue;
2146                         }
2147                 if (mddev->level == LEVEL_MULTIPATH) {
2148                         rdev->desc_nr = i++;
2149                         rdev->raid_disk = rdev->desc_nr;
2150                         set_bit(In_sync, &rdev->flags);
2151                 } else if (rdev->raid_disk >= mddev->raid_disks) {
2152                         rdev->raid_disk = -1;
2153                         clear_bit(In_sync, &rdev->flags);
2154                 }
2155         }
2156
2157
2158
2159         if (mddev->recovery_cp != MaxSector &&
2160             mddev->level >= 1)
2161                 printk(KERN_ERR "md: %s: raid array is not clean"
2162                        " -- starting background reconstruction\n",
2163                        mdname(mddev));
2164
2165 }
2166
2167 static ssize_t
2168 safe_delay_show(mddev_t *mddev, char *page)
2169 {
2170         int msec = (mddev->safemode_delay*1000)/HZ;
2171         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2172 }
2173 static ssize_t
2174 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2175 {
2176         int scale=1;
2177         int dot=0;
2178         int i;
2179         unsigned long msec;
2180         char buf[30];
2181         char *e;
2182         /* remove a period, and count digits after it */
2183         if (len >= sizeof(buf))
2184                 return -EINVAL;
2185         strlcpy(buf, cbuf, len);
2186         buf[len] = 0;
2187         for (i=0; i<len; i++) {
2188                 if (dot) {
2189                         if (isdigit(buf[i])) {
2190                                 buf[i-1] = buf[i];
2191                                 scale *= 10;
2192                         }
2193                         buf[i] = 0;
2194                 } else if (buf[i] == '.') {
2195                         dot=1;
2196                         buf[i] = 0;
2197                 }
2198         }
2199         msec = simple_strtoul(buf, &e, 10);
2200         if (e == buf || (*e && *e != '\n'))
2201                 return -EINVAL;
2202         msec = (msec * 1000) / scale;
2203         if (msec == 0)
2204                 mddev->safemode_delay = 0;
2205         else {
2206                 mddev->safemode_delay = (msec*HZ)/1000;
2207                 if (mddev->safemode_delay == 0)
2208                         mddev->safemode_delay = 1;
2209         }
2210         return len;
2211 }
2212 static struct md_sysfs_entry md_safe_delay =
2213 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2214
2215 static ssize_t
2216 level_show(mddev_t *mddev, char *page)
2217 {
2218         struct mdk_personality *p = mddev->pers;
2219         if (p)
2220                 return sprintf(page, "%s\n", p->name);
2221         else if (mddev->clevel[0])
2222                 return sprintf(page, "%s\n", mddev->clevel);
2223         else if (mddev->level != LEVEL_NONE)
2224                 return sprintf(page, "%d\n", mddev->level);
2225         else
2226                 return 0;
2227 }
2228
2229 static ssize_t
2230 level_store(mddev_t *mddev, const char *buf, size_t len)
2231 {
2232         int rv = len;
2233         if (mddev->pers)
2234                 return -EBUSY;
2235         if (len == 0)
2236                 return 0;
2237         if (len >= sizeof(mddev->clevel))
2238                 return -ENOSPC;
2239         strncpy(mddev->clevel, buf, len);
2240         if (mddev->clevel[len-1] == '\n')
2241                 len--;
2242         mddev->clevel[len] = 0;
2243         mddev->level = LEVEL_NONE;
2244         return rv;
2245 }
2246
2247 static struct md_sysfs_entry md_level =
2248 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
2249
2250
2251 static ssize_t
2252 layout_show(mddev_t *mddev, char *page)
2253 {
2254         /* just a number, not meaningful for all levels */
2255         if (mddev->reshape_position != MaxSector &&
2256             mddev->layout != mddev->new_layout)
2257                 return sprintf(page, "%d (%d)\n",
2258                                mddev->new_layout, mddev->layout);
2259         return sprintf(page, "%d\n", mddev->layout);
2260 }
2261
2262 static ssize_t
2263 layout_store(mddev_t *mddev, const char *buf, size_t len)
2264 {
2265         char *e;
2266         unsigned long n = simple_strtoul(buf, &e, 10);
2267
2268         if (!*buf || (*e && *e != '\n'))
2269                 return -EINVAL;
2270
2271         if (mddev->pers)
2272                 return -EBUSY;
2273         if (mddev->reshape_position != MaxSector)
2274                 mddev->new_layout = n;
2275         else
2276                 mddev->layout = n;
2277         return len;
2278 }
2279 static struct md_sysfs_entry md_layout =
2280 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
2281
2282
2283 static ssize_t
2284 raid_disks_show(mddev_t *mddev, char *page)
2285 {
2286         if (mddev->raid_disks == 0)
2287                 return 0;
2288         if (mddev->reshape_position != MaxSector &&
2289             mddev->delta_disks != 0)
2290                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
2291                                mddev->raid_disks - mddev->delta_disks);
2292         return sprintf(page, "%d\n", mddev->raid_disks);
2293 }
2294
2295 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2296
2297 static ssize_t
2298 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2299 {
2300         char *e;
2301         int rv = 0;
2302         unsigned long n = simple_strtoul(buf, &e, 10);
2303
2304         if (!*buf || (*e && *e != '\n'))
2305                 return -EINVAL;
2306
2307         if (mddev->pers)
2308                 rv = update_raid_disks(mddev, n);
2309         else if (mddev->reshape_position != MaxSector) {
2310                 int olddisks = mddev->raid_disks - mddev->delta_disks;
2311                 mddev->delta_disks = n - olddisks;
2312                 mddev->raid_disks = n;
2313         } else
2314                 mddev->raid_disks = n;
2315         return rv ? rv : len;
2316 }
2317 static struct md_sysfs_entry md_raid_disks =
2318 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
2319
2320 static ssize_t
2321 chunk_size_show(mddev_t *mddev, char *page)
2322 {
2323         if (mddev->reshape_position != MaxSector &&
2324             mddev->chunk_size != mddev->new_chunk)
2325                 return sprintf(page, "%d (%d)\n", mddev->new_chunk,
2326                                mddev->chunk_size);
2327         return sprintf(page, "%d\n", mddev->chunk_size);
2328 }
2329
2330 static ssize_t
2331 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2332 {
2333         /* can only set chunk_size if array is not yet active */
2334         char *e;
2335         unsigned long n = simple_strtoul(buf, &e, 10);
2336
2337         if (!*buf || (*e && *e != '\n'))
2338                 return -EINVAL;
2339
2340         if (mddev->pers)
2341                 return -EBUSY;
2342         else if (mddev->reshape_position != MaxSector)
2343                 mddev->new_chunk = n;
2344         else
2345                 mddev->chunk_size = n;
2346         return len;
2347 }
2348 static struct md_sysfs_entry md_chunk_size =
2349 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
2350
2351 static ssize_t
2352 resync_start_show(mddev_t *mddev, char *page)
2353 {
2354         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
2355 }
2356
2357 static ssize_t
2358 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
2359 {
2360         /* can only set chunk_size if array is not yet active */
2361         char *e;
2362         unsigned long long n = simple_strtoull(buf, &e, 10);
2363
2364         if (mddev->pers)
2365                 return -EBUSY;
2366         if (!*buf || (*e && *e != '\n'))
2367                 return -EINVAL;
2368
2369         mddev->recovery_cp = n;
2370         return len;
2371 }
2372 static struct md_sysfs_entry md_resync_start =
2373 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
2374
2375 /*
2376  * The array state can be:
2377  *
2378  * clear
2379  *     No devices, no size, no level
2380  *     Equivalent to STOP_ARRAY ioctl
2381  * inactive
2382  *     May have some settings, but array is not active
2383  *        all IO results in error
2384  *     When written, doesn't tear down array, but just stops it
2385  * suspended (not supported yet)
2386  *     All IO requests will block. The array can be reconfigured.
2387  *     Writing this, if accepted, will block until array is quiessent
2388  * readonly
2389  *     no resync can happen.  no superblocks get written.
2390  *     write requests fail
2391  * read-auto
2392  *     like readonly, but behaves like 'clean' on a write request.
2393  *
2394  * clean - no pending writes, but otherwise active.
2395  *     When written to inactive array, starts without resync
2396  *     If a write request arrives then
2397  *       if metadata is known, mark 'dirty' and switch to 'active'.
2398  *       if not known, block and switch to write-pending
2399  *     If written to an active array that has pending writes, then fails.
2400  * active
2401  *     fully active: IO and resync can be happening.
2402  *     When written to inactive array, starts with resync
2403  *
2404  * write-pending
2405  *     clean, but writes are blocked waiting for 'active' to be written.
2406  *
2407  * active-idle
2408  *     like active, but no writes have been seen for a while (100msec).
2409  *
2410  */
2411 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
2412                    write_pending, active_idle, bad_word};
2413 static char *array_states[] = {
2414         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
2415         "write-pending", "active-idle", NULL };
2416
2417 static int match_word(const char *word, char **list)
2418 {
2419         int n;
2420         for (n=0; list[n]; n++)
2421                 if (cmd_match(word, list[n]))
2422                         break;
2423         return n;
2424 }
2425
2426 static ssize_t
2427 array_state_show(mddev_t *mddev, char *page)
2428 {
2429         enum array_state st = inactive;
2430
2431         if (mddev->pers)
2432                 switch(mddev->ro) {
2433                 case 1:
2434                         st = readonly;
2435                         break;
2436                 case 2:
2437                         st = read_auto;
2438                         break;
2439                 case 0:
2440                         if (mddev->in_sync)
2441                                 st = clean;
2442                         else if (mddev->safemode)
2443                                 st = active_idle;
2444                         else
2445                                 st = active;
2446                 }
2447         else {
2448                 if (list_empty(&mddev->disks) &&
2449                     mddev->raid_disks == 0 &&
2450                     mddev->size == 0)
2451                         st = clear;
2452                 else
2453                         st = inactive;
2454         }
2455         return sprintf(page, "%s\n", array_states[st]);
2456 }
2457
2458 static int do_md_stop(mddev_t * mddev, int ro);
2459 static int do_md_run(mddev_t * mddev);
2460 static int restart_array(mddev_t *mddev);
2461
2462 static ssize_t
2463 array_state_store(mddev_t *mddev, const char *buf, size_t len)
2464 {
2465         int err = -EINVAL;
2466         enum array_state st = match_word(buf, array_states);
2467         switch(st) {
2468         case bad_word:
2469                 break;
2470         case clear:
2471                 /* stopping an active array */
2472                 if (mddev->pers) {
2473                         if (atomic_read(&mddev->active) > 1)
2474                                 return -EBUSY;
2475                         err = do_md_stop(mddev, 0);
2476                 }
2477                 break;
2478         case inactive:
2479                 /* stopping an active array */
2480                 if (mddev->pers) {
2481                         if (atomic_read(&mddev->active) > 1)
2482                                 return -EBUSY;
2483                         err = do_md_stop(mddev, 2);
2484                 }
2485                 break;
2486         case suspended:
2487                 break; /* not supported yet */
2488         case readonly:
2489                 if (mddev->pers)
2490                         err = do_md_stop(mddev, 1);
2491                 else {
2492                         mddev->ro = 1;
2493                         err = do_md_run(mddev);
2494                 }
2495                 break;
2496         case read_auto:
2497                 /* stopping an active array */
2498                 if (mddev->pers) {
2499                         err = do_md_stop(mddev, 1);
2500                         if (err == 0)
2501                                 mddev->ro = 2; /* FIXME mark devices writable */
2502                 } else {
2503                         mddev->ro = 2;
2504                         err = do_md_run(mddev);
2505                 }
2506                 break;
2507         case clean:
2508                 if (mddev->pers) {
2509                         restart_array(mddev);
2510                         spin_lock_irq(&mddev->write_lock);
2511                         if (atomic_read(&mddev->writes_pending) == 0) {
2512                                 mddev->in_sync = 1;
2513                                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
2514                         }
2515                         spin_unlock_irq(&mddev->write_lock);
2516                 } else {
2517                         mddev->ro = 0;
2518                         mddev->recovery_cp = MaxSector;
2519                         err = do_md_run(mddev);
2520                 }
2521                 break;
2522         case active:
2523                 if (mddev->pers) {
2524                         restart_array(mddev);
2525                         clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2526                         wake_up(&mddev->sb_wait);
2527                         err = 0;
2528                 } else {
2529                         mddev->ro = 0;
2530                         err = do_md_run(mddev);
2531                 }
2532                 break;
2533         case write_pending:
2534         case active_idle:
2535                 /* these cannot be set */
2536                 break;
2537         }
2538         if (err)
2539                 return err;
2540         else
2541                 return len;
2542 }
2543 static struct md_sysfs_entry md_array_state =
2544 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
2545
2546 static ssize_t
2547 null_show(mddev_t *mddev, char *page)
2548 {
2549         return -EINVAL;
2550 }
2551
2552 static ssize_t
2553 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
2554 {
2555         /* buf must be %d:%d\n? giving major and minor numbers */
2556         /* The new device is added to the array.
2557          * If the array has a persistent superblock, we read the
2558          * superblock to initialise info and check validity.
2559          * Otherwise, only checking done is that in bind_rdev_to_array,
2560          * which mainly checks size.
2561          */
2562         char *e;
2563         int major = simple_strtoul(buf, &e, 10);
2564         int minor;
2565         dev_t dev;
2566         mdk_rdev_t *rdev;
2567         int err;
2568
2569         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
2570                 return -EINVAL;
2571         minor = simple_strtoul(e+1, &e, 10);
2572         if (*e && *e != '\n')
2573                 return -EINVAL;
2574         dev = MKDEV(major, minor);
2575         if (major != MAJOR(dev) ||
2576             minor != MINOR(dev))
2577                 return -EOVERFLOW;
2578
2579
2580         if (mddev->persistent) {
2581                 rdev = md_import_device(dev, mddev->major_version,
2582                                         mddev->minor_version);
2583                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
2584                         mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
2585                                                        mdk_rdev_t, same_set);
2586                         err = super_types[mddev->major_version]
2587                                 .load_super(rdev, rdev0, mddev->minor_version);
2588                         if (err < 0)
2589                                 goto out;
2590                 }
2591         } else
2592                 rdev = md_import_device(dev, -1, -1);
2593
2594         if (IS_ERR(rdev))
2595                 return PTR_ERR(rdev);
2596         err = bind_rdev_to_array(rdev, mddev);
2597  out:
2598         if (err)
2599                 export_rdev(rdev);
2600         return err ? err : len;
2601 }
2602
2603 static struct md_sysfs_entry md_new_device =
2604 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
2605
2606 static ssize_t
2607 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
2608 {
2609         char *end;
2610         unsigned long chunk, end_chunk;
2611
2612         if (!mddev->bitmap)
2613                 goto out;
2614         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
2615         while (*buf) {
2616                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
2617                 if (buf == end) break;
2618                 if (*end == '-') { /* range */
2619                         buf = end + 1;
2620                         end_chunk = simple_strtoul(buf, &end, 0);
2621                         if (buf == end) break;
2622                 }
2623                 if (*end && !isspace(*end)) break;
2624                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
2625                 buf = end;
2626                 while (isspace(*buf)) buf++;
2627         }
2628         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
2629 out:
2630         return len;
2631 }
2632
2633 static struct md_sysfs_entry md_bitmap =
2634 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
2635
2636 static ssize_t
2637 size_show(mddev_t *mddev, char *page)
2638 {
2639         return sprintf(page, "%llu\n", (unsigned long long)mddev->size);
2640 }
2641
2642 static int update_size(mddev_t *mddev, unsigned long size);
2643
2644 static ssize_t
2645 size_store(mddev_t *mddev, const char *buf, size_t len)
2646 {
2647         /* If array is inactive, we can reduce the component size, but
2648          * not increase it (except from 0).
2649          * If array is active, we can try an on-line resize
2650          */
2651         char *e;
2652         int err = 0;
2653         unsigned long long size = simple_strtoull(buf, &e, 10);
2654         if (!*buf || *buf == '\n' ||
2655             (*e && *e != '\n'))
2656                 return -EINVAL;
2657
2658         if (mddev->pers) {
2659                 err = update_size(mddev, size);
2660                 md_update_sb(mddev, 1);
2661         } else {
2662                 if (mddev->size == 0 ||
2663                     mddev->size > size)
2664                         mddev->size = size;
2665                 else
2666                         err = -ENOSPC;
2667         }
2668         return err ? err : len;
2669 }
2670
2671 static struct md_sysfs_entry md_size =
2672 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
2673
2674
2675 /* Metdata version.
2676  * This is either 'none' for arrays with externally managed metadata,
2677  * or N.M for internally known formats
2678  */
2679 static ssize_t
2680 metadata_show(mddev_t *mddev, char *page)
2681 {
2682         if (mddev->persistent)
2683                 return sprintf(page, "%d.%d\n",
2684                                mddev->major_version, mddev->minor_version);
2685         else
2686                 return sprintf(page, "none\n");
2687 }
2688
2689 static ssize_t
2690 metadata_store(mddev_t *mddev, const char *buf, size_t len)
2691 {
2692         int major, minor;
2693         char *e;
2694         if (!list_empty(&mddev->disks))
2695                 return -EBUSY;
2696
2697         if (cmd_match(buf, "none")) {
2698                 mddev->persistent = 0;
2699                 mddev->major_version = 0;
2700                 mddev->minor_version = 90;
2701                 return len;
2702         }
2703         major = simple_strtoul(buf, &e, 10);
2704         if (e==buf || *e != '.')
2705                 return -EINVAL;
2706         buf = e+1;
2707         minor = simple_strtoul(buf, &e, 10);
2708         if (e==buf || (*e && *e != '\n') )
2709                 return -EINVAL;
2710         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
2711                 return -ENOENT;
2712         mddev->major_version = major;
2713         mddev->minor_version = minor;
2714         mddev->persistent = 1;
2715         return len;
2716 }
2717
2718 static struct md_sysfs_entry md_metadata =
2719 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2720
2721 static ssize_t
2722 action_show(mddev_t *mddev, char *page)
2723 {
2724         char *type = "idle";
2725         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2726             test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) {
2727                 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
2728                         type = "reshape";
2729                 else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2730                         if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2731                                 type = "resync";
2732                         else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
2733                                 type = "check";
2734                         else
2735                                 type = "repair";
2736                 } else
2737                         type = "recover";
2738         }
2739         return sprintf(page, "%s\n", type);
2740 }
2741
2742 static ssize_t
2743 action_store(mddev_t *mddev, const char *page, size_t len)
2744 {
2745         if (!mddev->pers || !mddev->pers->sync_request)
2746                 return -EINVAL;
2747
2748         if (cmd_match(page, "idle")) {
2749                 if (mddev->sync_thread) {
2750                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2751                         md_unregister_thread(mddev->sync_thread);
2752                         mddev->sync_thread = NULL;
2753                         mddev->recovery = 0;
2754                 }
2755         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2756                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
2757                 return -EBUSY;
2758         else if (cmd_match(page, "resync") || cmd_match(page, "recover"))
2759                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2760         else if (cmd_match(page, "reshape")) {
2761                 int err;
2762                 if (mddev->pers->start_reshape == NULL)
2763                         return -EINVAL;
2764                 err = mddev->pers->start_reshape(mddev);
2765                 if (err)
2766                         return err;
2767         } else {
2768                 if (cmd_match(page, "check"))
2769                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
2770                 else if (!cmd_match(page, "repair"))
2771                         return -EINVAL;
2772                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
2773                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
2774         }
2775         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2776         md_wakeup_thread(mddev->thread);
2777         return len;
2778 }
2779
2780 static ssize_t
2781 mismatch_cnt_show(mddev_t *mddev, char *page)
2782 {
2783         return sprintf(page, "%llu\n",
2784                        (unsigned long long) mddev->resync_mismatches);
2785 }
2786
2787 static struct md_sysfs_entry md_scan_mode =
2788 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
2789
2790
2791 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
2792
2793 static ssize_t
2794 sync_min_show(mddev_t *mddev, char *page)
2795 {
2796         return sprintf(page, "%d (%s)\n", speed_min(mddev),
2797                        mddev->sync_speed_min ? "local": "system");
2798 }
2799
2800 static ssize_t
2801 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
2802 {
2803         int min;
2804         char *e;
2805         if (strncmp(buf, "system", 6)==0) {
2806                 mddev->sync_speed_min = 0;
2807                 return len;
2808         }
2809         min = simple_strtoul(buf, &e, 10);
2810         if (buf == e || (*e && *e != '\n') || min <= 0)
2811                 return -EINVAL;
2812         mddev->sync_speed_min = min;
2813         return len;
2814 }
2815
2816 static struct md_sysfs_entry md_sync_min =
2817 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
2818
2819 static ssize_t
2820 sync_max_show(mddev_t *mddev, char *page)
2821 {
2822         return sprintf(page, "%d (%s)\n", speed_max(mddev),
2823                        mddev->sync_speed_max ? "local": "system");
2824 }
2825
2826 static ssize_t
2827 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
2828 {
2829         int max;
2830         char *e;
2831         if (strncmp(buf, "system", 6)==0) {
2832                 mddev->sync_speed_max = 0;
2833                 return len;
2834         }
2835         max = simple_strtoul(buf, &e, 10);
2836         if (buf == e || (*e && *e != '\n') || max <= 0)
2837                 return -EINVAL;
2838         mddev->sync_speed_max = max;
2839         return len;
2840 }
2841
2842 static struct md_sysfs_entry md_sync_max =
2843 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
2844
2845
2846 static ssize_t
2847 sync_speed_show(mddev_t *mddev, char *page)
2848 {
2849         unsigned long resync, dt, db;
2850         resync = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active));
2851         dt = ((jiffies - mddev->resync_mark) / HZ);
2852         if (!dt) dt++;
2853         db = resync - (mddev->resync_mark_cnt);
2854         return sprintf(page, "%ld\n", db/dt/2); /* K/sec */
2855 }
2856
2857 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
2858
2859 static ssize_t
2860 sync_completed_show(mddev_t *mddev, char *page)
2861 {
2862         unsigned long max_blocks, resync;
2863
2864         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2865                 max_blocks = mddev->resync_max_sectors;
2866         else
2867                 max_blocks = mddev->size << 1;
2868
2869         resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
2870         return sprintf(page, "%lu / %lu\n", resync, max_blocks);
2871 }
2872
2873 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
2874
2875 static ssize_t
2876 suspend_lo_show(mddev_t *mddev, char *page)
2877 {
2878         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
2879 }
2880
2881 static ssize_t
2882 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
2883 {
2884         char *e;
2885         unsigned long long new = simple_strtoull(buf, &e, 10);
2886
2887         if (mddev->pers->quiesce == NULL)
2888                 return -EINVAL;
2889         if (buf == e || (*e && *e != '\n'))
2890                 return -EINVAL;
2891         if (new >= mddev->suspend_hi ||
2892             (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
2893                 mddev->suspend_lo = new;
2894                 mddev->pers->quiesce(mddev, 2);
2895                 return len;
2896         } else
2897                 return -EINVAL;
2898 }
2899 static struct md_sysfs_entry md_suspend_lo =
2900 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
2901
2902
2903 static ssize_t
2904 suspend_hi_show(mddev_t *mddev, char *page)
2905 {
2906         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
2907 }
2908
2909 static ssize_t
2910 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
2911 {
2912         char *e;
2913         unsigned long long new = simple_strtoull(buf, &e, 10);
2914
2915         if (mddev->pers->quiesce == NULL)
2916                 return -EINVAL;
2917         if (buf == e || (*e && *e != '\n'))
2918                 return -EINVAL;
2919         if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
2920             (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
2921                 mddev->suspend_hi = new;
2922                 mddev->pers->quiesce(mddev, 1);
2923                 mddev->pers->quiesce(mddev, 0);
2924                 return len;
2925         } else
2926                 return -EINVAL;
2927 }
2928 static struct md_sysfs_entry md_suspend_hi =
2929 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
2930
2931 static ssize_t
2932 reshape_position_show(mddev_t *mddev, char *page)
2933 {
2934         if (mddev->reshape_position != MaxSector)
2935                 return sprintf(page, "%llu\n",
2936                                (unsigned long long)mddev->reshape_position);
2937         strcpy(page, "none\n");
2938         return 5;
2939 }
2940
2941 static ssize_t
2942 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
2943 {
2944         char *e;
2945         unsigned long long new = simple_strtoull(buf, &e, 10);
2946         if (mddev->pers)
2947                 return -EBUSY;
2948         if (buf == e || (*e && *e != '\n'))
2949                 return -EINVAL;
2950         mddev->reshape_position = new;
2951         mddev->delta_disks = 0;
2952         mddev->new_level = mddev->level;
2953         mddev->new_layout = mddev->layout;
2954         mddev->new_chunk = mddev->chunk_size;
2955         return len;
2956 }
2957
2958 static struct md_sysfs_entry md_reshape_position =
2959 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
2960        reshape_position_store);
2961
2962
2963 static struct attribute *md_default_attrs[] = {
2964         &md_level.attr,
2965         &md_layout.attr,
2966         &md_raid_disks.attr,
2967         &md_chunk_size.attr,
2968         &md_size.attr,
2969         &md_resync_start.attr,
2970         &md_metadata.attr,
2971         &md_new_device.attr,
2972         &md_safe_delay.attr,
2973         &md_array_state.attr,
2974         &md_reshape_position.attr,
2975         NULL,
2976 };
2977
2978 static struct attribute *md_redundancy_attrs[] = {
2979         &md_scan_mode.attr,
2980         &md_mismatches.attr,
2981         &md_sync_min.attr,
2982         &md_sync_max.attr,
2983         &md_sync_speed.attr,
2984         &md_sync_completed.attr,
2985         &md_suspend_lo.attr,
2986         &md_suspend_hi.attr,
2987         &md_bitmap.attr,
2988         NULL,
2989 };
2990 static struct attribute_group md_redundancy_group = {
2991         .name = NULL,
2992         .attrs = md_redundancy_attrs,
2993 };
2994
2995
2996 static ssize_t
2997 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2998 {
2999         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3000         mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3001         ssize_t rv;
3002
3003         if (!entry->show)
3004                 return -EIO;
3005         rv = mddev_lock(mddev);
3006         if (!rv) {
3007                 rv = entry->show(mddev, page);
3008                 mddev_unlock(mddev);
3009         }
3010         return rv;
3011 }
3012
3013 static ssize_t
3014 md_attr_store(struct kobject *kobj, struct attribute *attr,
3015               const char *page, size_t length)
3016 {
3017         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3018         mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3019         ssize_t rv;
3020
3021         if (!entry->store)
3022                 return -EIO;
3023         if (!capable(CAP_SYS_ADMIN))
3024                 return -EACCES;
3025         rv = mddev_lock(mddev);
3026         if (!rv) {
3027                 rv = entry->store(mddev, page, length);
3028                 mddev_unlock(mddev);
3029         }
3030         return rv;
3031 }
3032
3033 static void md_free(struct kobject *ko)
3034 {
3035         mddev_t *mddev = container_of(ko, mddev_t, kobj);
3036         kfree(mddev);
3037 }
3038
3039 static struct sysfs_ops md_sysfs_ops = {
3040         .show   = md_attr_show,
3041         .store  = md_attr_store,
3042 };
3043 static struct kobj_type md_ktype = {
3044         .release        = md_free,
3045         .sysfs_ops      = &md_sysfs_ops,
3046         .default_attrs  = md_default_attrs,
3047 };
3048
3049 int mdp_major = 0;
3050
3051 static struct kobject *md_probe(dev_t dev, int *part, void *data)
3052 {
3053         static DEFINE_MUTEX(disks_mutex);
3054         mddev_t *mddev = mddev_find(dev);
3055         struct gendisk *disk;
3056         int partitioned = (MAJOR(dev) != MD_MAJOR);
3057         int shift = partitioned ? MdpMinorShift : 0;
3058         int unit = MINOR(dev) >> shift;
3059
3060         if (!mddev)
3061                 return NULL;
3062
3063         mutex_lock(&disks_mutex);
3064         if (mddev->gendisk) {
3065                 mutex_unlock(&disks_mutex);
3066                 mddev_put(mddev);
3067                 return NULL;
3068         }
3069         disk = alloc_disk(1 << shift);
3070         if (!disk) {
3071                 mutex_unlock(&disks_mutex);
3072                 mddev_put(mddev);
3073                 return NULL;
3074         }
3075         disk->major = MAJOR(dev);
3076         disk->first_minor = unit << shift;
3077         if (partitioned)
3078                 sprintf(disk->disk_name, "md_d%d", unit);
3079         else
3080                 sprintf(disk->disk_name, "md%d", unit);
3081         disk->fops = &md_fops;
3082         disk->private_data = mddev;
3083         disk->queue = mddev->queue;
3084         add_disk(disk);
3085         mddev->gendisk = disk;
3086         mutex_unlock(&disks_mutex);
3087         mddev->kobj.parent = &disk->kobj;
3088         mddev->kobj.k_name = NULL;
3089         snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
3090         mddev->kobj.ktype = &md_ktype;
3091         if (kobject_register(&mddev->kobj))
3092                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
3093                        disk->disk_name);
3094         return NULL;
3095 }
3096
3097 static void md_safemode_timeout(unsigned long data)
3098 {
3099         mddev_t *mddev = (mddev_t *) data;
3100
3101         mddev->safemode = 1;
3102         md_wakeup_thread(mddev->thread);
3103 }
3104
3105 static int start_dirty_degraded;
3106
3107 static int do_md_run(mddev_t * mddev)
3108 {
3109         int err;
3110         int chunk_size;
3111         struct list_head *tmp;
3112         mdk_rdev_t *rdev;
3113         struct gendisk *disk;
3114         struct mdk_personality *pers;
3115         char b[BDEVNAME_SIZE];
3116
3117         if (list_empty(&mddev->disks))
3118                 /* cannot run an array with no devices.. */
3119                 return -EINVAL;
3120
3121         if (mddev->pers)
3122                 return -EBUSY;
3123
3124         /*
3125          * Analyze all RAID superblock(s)
3126          */
3127         if (!mddev->raid_disks)
3128                 analyze_sbs(mddev);
3129
3130         chunk_size = mddev->chunk_size;
3131
3132         if (chunk_size) {
3133                 if (chunk_size > MAX_CHUNK_SIZE) {
3134                         printk(KERN_ERR "too big chunk_size: %d > %d\n",
3135                                 chunk_size, MAX_CHUNK_SIZE);
3136                         return -EINVAL;
3137                 }
3138                 /*
3139                  * chunk-size has to be a power of 2 and multiples of PAGE_SIZE
3140                  */
3141                 if ( (1 << ffz(~chunk_size)) != chunk_size) {
3142                         printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
3143                         return -EINVAL;
3144                 }
3145                 if (chunk_size < PAGE_SIZE) {
3146                         printk(KERN_ERR "too small chunk_size: %d < %ld\n",
3147                                 chunk_size, PAGE_SIZE);
3148                         return -EINVAL;
3149                 }
3150
3151                 /* devices must have minimum size of one chunk */
3152                 ITERATE_RDEV(mddev,rdev,tmp) {
3153                         if (test_bit(Faulty, &rdev->flags))
3154                                 continue;
3155                         if (rdev->size < chunk_size / 1024) {
3156                                 printk(KERN_WARNING
3157                                         "md: Dev %s smaller than chunk_size:"
3158                                         " %lluk < %dk\n",
3159                                         bdevname(rdev->bdev,b),
3160                                         (unsigned long long)rdev->size,
3161                                         chunk_size / 1024);
3162                                 return -EINVAL;
3163                         }
3164                 }
3165         }
3166
3167 #ifdef CONFIG_KMOD
3168         if (mddev->level != LEVEL_NONE)
3169                 request_module("md-level-%d", mddev->level);
3170         else if (mddev->clevel[0])
3171                 request_module("md-%s", mddev->clevel);
3172 #endif
3173
3174         /*
3175          * Drop all container device buffers, from now on
3176          * the only valid external interface is through the md
3177          * device.
3178          */
3179         ITERATE_RDEV(mddev,rdev,tmp) {
3180                 if (test_bit(Faulty, &rdev->flags))
3181                         continue;
3182                 sync_blockdev(rdev->bdev);
3183                 invalidate_bdev(rdev->bdev);
3184
3185                 /* perform some consistency tests on the device.
3186                  * We don't want the data to overlap the metadata,
3187                  * Internal Bitmap issues has handled elsewhere.
3188                  */
3189                 if (rdev->data_offset < rdev->sb_offset) {
3190                         if (mddev->size &&
3191                             rdev->data_offset + mddev->size*2
3192                             > rdev->sb_offset*2) {
3193                                 printk("md: %s: data overlaps metadata\n",
3194                                        mdname(mddev));
3195                                 return -EINVAL;
3196                         }
3197                 } else {
3198                         if (rdev->sb_offset*2 + rdev->sb_size/512
3199                             > rdev->data_offset) {
3200                                 printk("md: %s: metadata overlaps data\n",
3201                                        mdname(mddev));
3202                                 return -EINVAL;
3203                         }
3204                 }
3205         }
3206
3207         md_probe(mddev->unit, NULL, NULL);
3208         disk = mddev->gendisk;
3209         if (!disk)
3210                 return -ENOMEM;
3211
3212         spin_lock(&pers_lock);
3213         pers = find_pers(mddev->level, mddev->clevel);
3214         if (!pers || !try_module_get(pers->owner)) {
3215                 spin_unlock(&pers_lock);
3216                 if (mddev->level != LEVEL_NONE)
3217                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
3218                                mddev->level);
3219                 else
3220                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
3221                                mddev->clevel);
3222                 return -EINVAL;
3223         }
3224         mddev->pers = pers;
3225         spin_unlock(&pers_lock);
3226         mddev->level = pers->level;
3227         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3228
3229         if (mddev->reshape_position != MaxSector &&
3230             pers->start_reshape == NULL) {
3231                 /* This personality cannot handle reshaping... */
3232                 mddev->pers = NULL;
3233                 module_put(pers->owner);
3234                 return -EINVAL;
3235         }
3236
3237         if (pers->sync_request) {
3238                 /* Warn if this is a potentially silly
3239                  * configuration.
3240                  */
3241                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
3242                 mdk_rdev_t *rdev2;
3243                 struct list_head *tmp2;
3244                 int warned = 0;
3245                 ITERATE_RDEV(mddev, rdev, tmp) {
3246                         ITERATE_RDEV(mddev, rdev2, tmp2) {
3247                                 if (rdev < rdev2 &&
3248                                     rdev->bdev->bd_contains ==
3249                                     rdev2->bdev->bd_contains) {
3250                                         printk(KERN_WARNING
3251                                                "%s: WARNING: %s appears to be"
3252                                                " on the same physical disk as"
3253                                                " %s.\n",
3254                                                mdname(mddev),
3255                                                bdevname(rdev->bdev,b),
3256                                                bdevname(rdev2->bdev,b2));
3257                                         warned = 1;
3258                                 }
3259                         }
3260                 }
3261                 if (warned)
3262                         printk(KERN_WARNING
3263                                "True protection against single-disk"
3264                                " failure might be compromised.\n");
3265         }
3266
3267         mddev->recovery = 0;
3268         mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
3269         mddev->barriers_work = 1;
3270         mddev->ok_start_degraded = start_dirty_degraded;
3271
3272         if (start_readonly)
3273                 mddev->ro = 2; /* read-only, but switch on first write */
3274
3275         err = mddev->pers->run(mddev);
3276         if (!err && mddev->pers->sync_request) {
3277                 err = bitmap_create(mddev);
3278                 if (err) {
3279                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
3280                                mdname(mddev), err);
3281                         mddev->pers->stop(mddev);
3282                 }
3283         }
3284         if (err) {
3285                 printk(KERN_ERR "md: pers->run() failed ...\n");
3286                 module_put(mddev->pers->owner);
3287                 mddev->pers = NULL;
3288                 bitmap_destroy(mddev);
3289                 return err;
3290         }
3291         if (mddev->pers->sync_request) {
3292                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3293                         printk(KERN_WARNING
3294                                "md: cannot register extra attributes for %s\n",
3295                                mdname(mddev));
3296         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
3297                 mddev->ro = 0;
3298
3299         atomic_set(&mddev->writes_pending,0);
3300         mddev->safemode = 0;
3301         mddev->safemode_timer.function = md_safemode_timeout;
3302         mddev->safemode_timer.data = (unsigned long) mddev;
3303         mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
3304         mddev->in_sync = 1;
3305
3306         ITERATE_RDEV(mddev,rdev,tmp)
3307                 if (rdev->raid_disk >= 0) {
3308                         char nm[20];
3309                         sprintf(nm, "rd%d", rdev->raid_disk);
3310                         if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
3311                                 printk("md: cannot register %s for %s\n",
3312                                        nm, mdname(mddev));
3313                 }
3314         
3315         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3316         
3317         if (mddev->flags)
3318                 md_update_sb(mddev, 0);
3319
3320         set_capacity(disk, mddev->array_size<<1);
3321
3322         /* If we call blk_queue_make_request here, it will
3323          * re-initialise max_sectors etc which may have been
3324          * refined inside -> run.  So just set the bits we need to set.
3325          * Most initialisation happended when we called
3326          * blk_queue_make_request(..., md_fail_request)
3327          * earlier.
3328          */
3329         mddev->queue->queuedata = mddev;
3330         mddev->queue->make_request_fn = mddev->pers->make_request;
3331
3332         /* If there is a partially-recovered drive we need to
3333          * start recovery here.  If we leave it to md_check_recovery,
3334          * it will remove the drives and not do the right thing
3335          */
3336         if (mddev->degraded && !mddev->sync_thread) {
3337                 struct list_head *rtmp;
3338                 int spares = 0;
3339                 ITERATE_RDEV(mddev,rdev,rtmp)
3340                         if (rdev->raid_disk >= 0 &&
3341                             !test_bit(In_sync, &rdev->flags) &&
3342                             !test_bit(Faulty, &rdev->flags))
3343                                 /* complete an interrupted recovery */
3344                                 spares++;
3345                 if (spares && mddev->pers->sync_request) {
3346                         mddev->recovery = 0;
3347                         set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3348                         mddev->sync_thread = md_register_thread(md_do_sync,
3349                                                                 mddev,
3350                                                                 "%s_resync");
3351                         if (!mddev->sync_thread) {
3352                                 printk(KERN_ERR "%s: could not start resync"
3353                                        " thread...\n",
3354                                        mdname(mddev));
3355                                 /* leave the spares where they are, it shouldn't hurt */
3356                                 mddev->recovery = 0;
3357                         }
3358                 }
3359         }
3360         md_wakeup_thread(mddev->thread);
3361         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
3362
3363         mddev->changed = 1;
3364         md_new_event(mddev);
3365         kobject_uevent(&mddev->gendisk->kobj, KOBJ_CHANGE);
3366         return 0;
3367 }
3368
3369 static int restart_array(mddev_t *mddev)
3370 {
3371         struct gendisk *disk = mddev->gendisk;
3372         int err;
3373
3374         /*
3375          * Complain if it has no devices
3376          */
3377         err = -ENXIO;
3378         if (list_empty(&mddev->disks))
3379                 goto out;
3380
3381         if (mddev->pers) {
3382                 err = -EBUSY;
3383                 if (!mddev->ro)
3384                         goto out;
3385
3386                 mddev->safemode = 0;
3387                 mddev->ro = 0;
3388                 set_disk_ro(disk, 0);
3389
3390                 printk(KERN_INFO "md: %s switched to read-write mode.\n",
3391                         mdname(mddev));
3392                 /*
3393                  * Kick recovery or resync if necessary
3394                  */
3395                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3396                 md_wakeup_thread(mddev->thread);
3397                 md_wakeup_thread(mddev->sync_thread);
3398                 err = 0;
3399         } else
3400                 err = -EINVAL;
3401
3402 out:
3403         return err;
3404 }
3405
3406 /* similar to deny_write_access, but accounts for our holding a reference
3407  * to the file ourselves */
3408 static int deny_bitmap_write_access(struct file * file)
3409 {
3410         struct inode *inode = file->f_mapping->host;
3411
3412         spin_lock(&inode->i_lock);
3413         if (atomic_read(&inode->i_writecount) > 1) {
3414                 spin_unlock(&inode->i_lock);
3415                 return -ETXTBSY;
3416         }
3417         atomic_set(&inode->i_writecount, -1);
3418         spin_unlock(&inode->i_lock);
3419
3420         return 0;
3421 }
3422
3423 static void restore_bitmap_write_access(struct file *file)
3424 {
3425         struct inode *inode = file->f_mapping->host;
3426
3427         spin_lock(&inode->i_lock);
3428         atomic_set(&inode->i_writecount, 1);
3429         spin_unlock(&inode->i_lock);
3430 }
3431
3432 /* mode:
3433  *   0 - completely stop and dis-assemble array
3434  *   1 - switch to readonly
3435  *   2 - stop but do not disassemble array
3436  */
3437 static int do_md_stop(mddev_t * mddev, int mode)
3438 {
3439         int err = 0;
3440         struct gendisk *disk = mddev->gendisk;
3441
3442         if (mddev->pers) {
3443                 if (atomic_read(&mddev->active)>2) {
3444                         printk("md: %s still in use.\n",mdname(mddev));
3445                         return -EBUSY;
3446                 }
3447
3448                 if (mddev->sync_thread) {
3449                         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3450                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3451                         md_unregister_thread(mddev->sync_thread);
3452                         mddev->sync_thread = NULL;
3453                 }
3454
3455                 del_timer_sync(&mddev->safemode_timer);
3456
3457                 invalidate_partition(disk, 0);
3458
3459                 switch(mode) {
3460                 case 1: /* readonly */
3461                         err  = -ENXIO;
3462                         if (mddev->ro==1)
3463                                 goto out;
3464                         mddev->ro = 1;
3465                         break;
3466                 case 0: /* disassemble */
3467                 case 2: /* stop */
3468                         bitmap_flush(mddev);
3469                         md_super_wait(mddev);
3470                         if (mddev->ro)
3471                                 set_disk_ro(disk, 0);
3472                         blk_queue_make_request(mddev->queue, md_fail_request);
3473                         mddev->pers->stop(mddev);
3474                         mddev->queue->merge_bvec_fn = NULL;
3475                         mddev->queue->unplug_fn = NULL;
3476                         mddev->queue->issue_flush_fn = NULL;
3477                         mddev->queue->backing_dev_info.congested_fn = NULL;
3478                         if (mddev->pers->sync_request)
3479                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
3480
3481                         module_put(mddev->pers->owner);
3482                         mddev->pers = NULL;
3483
3484                         set_capacity(disk, 0);
3485                         mddev->changed = 1;
3486
3487                         if (mddev->ro)
3488                                 mddev->ro = 0;
3489                 }
3490                 if (!mddev->in_sync || mddev->flags) {
3491                         /* mark array as shutdown cleanly */
3492                         mddev->in_sync = 1;
3493                         md_update_sb(mddev, 1);
3494                 }
3495                 if (mode == 1)
3496                         set_disk_ro(disk, 1);
3497                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3498         }
3499
3500         /*
3501          * Free resources if final stop
3502          */
3503         if (mode == 0) {
3504                 mdk_rdev_t *rdev;
3505                 struct list_head *tmp;
3506
3507                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
3508
3509                 bitmap_destroy(mddev);
3510                 if (mddev->bitmap_file) {
3511                         restore_bitmap_write_access(mddev->bitmap_file);
3512                         fput(mddev->bitmap_file);
3513                         mddev->bitmap_file = NULL;
3514                 }
3515                 mddev->bitmap_offset = 0;
3516
3517                 ITERATE_RDEV(mddev,rdev,tmp)
3518                         if (rdev->raid_disk >= 0) {
3519                                 char nm[20];
3520                                 sprintf(nm, "rd%d", rdev->raid_disk);
3521                                 sysfs_remove_link(&mddev->kobj, nm);
3522                         }
3523
3524                 /* make sure all delayed_delete calls have finished */
3525                 flush_scheduled_work();
3526
3527                 export_array(mddev);
3528
3529                 mddev->array_size = 0;
3530                 mddev->size = 0;
3531                 mddev->raid_disks = 0;
3532                 mddev->recovery_cp = 0;
3533                 mddev->reshape_position = MaxSector;
3534
3535         } else if (mddev->pers)
3536                 printk(KERN_INFO "md: %s switched to read-only mode.\n",
3537                         mdname(mddev));
3538         err = 0;
3539         md_new_event(mddev);
3540 out:
3541         return err;
3542 }
3543
3544 #ifndef MODULE
3545 static void autorun_array(mddev_t *mddev)
3546 {
3547         mdk_rdev_t *rdev;
3548         struct list_head *tmp;
3549         int err;
3550
3551         if (list_empty(&mddev->disks))
3552                 return;
3553
3554         printk(KERN_INFO "md: running: ");
3555
3556         ITERATE_RDEV(mddev,rdev,tmp) {
3557                 char b[BDEVNAME_SIZE];
3558                 printk("<%s>", bdevname(rdev->bdev,b));
3559         }
3560         printk("\n");
3561
3562         err = do_md_run (mddev);
3563         if (err) {
3564                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
3565                 do_md_stop (mddev, 0);
3566         }
3567 }
3568
3569 /*
3570  * lets try to run arrays based on all disks that have arrived
3571  * until now. (those are in pending_raid_disks)
3572  *
3573  * the method: pick the first pending disk, collect all disks with
3574  * the same UUID, remove all from the pending list and put them into
3575  * the 'same_array' list. Then order this list based on superblock
3576  * update time (freshest comes first), kick out 'old' disks and
3577  * compare superblocks. If everything's fine then run it.
3578  *
3579  * If "unit" is allocated, then bump its reference count
3580  */
3581 static void autorun_devices(int part)
3582 {
3583         struct list_head *tmp;
3584         mdk_rdev_t *rdev0, *rdev;
3585         mddev_t *mddev;
3586         char b[BDEVNAME_SIZE];
3587
3588         printk(KERN_INFO "md: autorun ...\n");
3589         while (!list_empty(&pending_raid_disks)) {
3590                 int unit;
3591                 dev_t dev;
3592                 LIST_HEAD(candidates);
3593                 rdev0 = list_entry(pending_raid_disks.next,
3594                                          mdk_rdev_t, same_set);
3595
3596                 printk(KERN_INFO "md: considering %s ...\n",
3597                         bdevname(rdev0->bdev,b));
3598                 INIT_LIST_HEAD(&candidates);
3599                 ITERATE_RDEV_PENDING(rdev,tmp)
3600                         if (super_90_load(rdev, rdev0, 0) >= 0) {
3601                                 printk(KERN_INFO "md:  adding %s ...\n",
3602                                         bdevname(rdev->bdev,b));
3603                                 list_move(&rdev->same_set, &candidates);
3604                         }
3605                 /*
3606                  * now we have a set of devices, with all of them having
3607                  * mostly sane superblocks. It's time to allocate the
3608                  * mddev.
3609                  */
3610                 if (part) {
3611                         dev = MKDEV(mdp_major,
3612                                     rdev0->preferred_minor << MdpMinorShift);
3613                         unit = MINOR(dev) >> MdpMinorShift;
3614                 } else {
3615                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
3616                         unit = MINOR(dev);
3617                 }
3618                 if (rdev0->preferred_minor != unit) {
3619                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
3620                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
3621                         break;
3622                 }
3623
3624                 md_probe(dev, NULL, NULL);
3625                 mddev = mddev_find(dev);
3626                 if (!mddev) {
3627                         printk(KERN_ERR 
3628                                 "md: cannot allocate memory for md drive.\n");
3629                         break;
3630                 }
3631                 if (mddev_lock(mddev)) 
3632                         printk(KERN_WARNING "md: %s locked, cannot run\n",
3633                                mdname(mddev));
3634                 else if (mddev->raid_disks || mddev->major_version
3635                          || !list_empty(&mddev->disks)) {
3636                         printk(KERN_WARNING 
3637                                 "md: %s already running, cannot run %s\n",
3638                                 mdname(mddev), bdevname(rdev0->bdev,b));
3639                         mddev_unlock(mddev);
3640                 } else {
3641                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
3642                         ITERATE_RDEV_GENERIC(candidates,rdev,tmp) {
3643                                 list_del_init(&rdev->same_set);
3644                                 if (bind_rdev_to_array(rdev, mddev))
3645                                         export_rdev(rdev);
3646                         }
3647                         autorun_array(mddev);
3648                         mddev_unlock(mddev);
3649                 }
3650                 /* on success, candidates will be empty, on error
3651                  * it won't...
3652                  */
3653                 ITERATE_RDEV_GENERIC(candidates,rdev,tmp)
3654                         export_rdev(rdev);
3655                 mddev_put(mddev);
3656         }
3657         printk(KERN_INFO "md: ... autorun DONE.\n");
3658 }
3659 #endif /* !MODULE */
3660
3661 static int get_version(void __user * arg)
3662 {
3663         mdu_version_t ver;
3664
3665         ver.major = MD_MAJOR_VERSION;
3666         ver.minor = MD_MINOR_VERSION;
3667         ver.patchlevel = MD_PATCHLEVEL_VERSION;
3668
3669         if (copy_to_user(arg, &ver, sizeof(ver)))
3670                 return -EFAULT;
3671
3672         return 0;
3673 }
3674
3675 static int get_array_info(mddev_t * mddev, void __user * arg)
3676 {
3677         mdu_array_info_t info;
3678         int nr,working,active,failed,spare;
3679         mdk_rdev_t *rdev;
3680         struct list_head *tmp;
3681
3682         nr=working=active=failed=spare=0;
3683         ITERATE_RDEV(mddev,rdev,tmp) {
3684                 nr++;
3685                 if (test_bit(Faulty, &rdev->flags))
3686                         failed++;
3687                 else {
3688                         working++;
3689                         if (test_bit(In_sync, &rdev->flags))
3690                                 active++;       
3691                         else
3692                                 spare++;
3693                 }
3694         }
3695
3696         info.major_version = mddev->major_version;
3697         info.minor_version = mddev->minor_version;
3698         info.patch_version = MD_PATCHLEVEL_VERSION;
3699         info.ctime         = mddev->ctime;
3700         info.level         = mddev->level;
3701         info.size          = mddev->size;
3702         if (info.size != mddev->size) /* overflow */
3703                 info.size = -1;
3704         info.nr_disks      = nr;
3705         info.raid_disks    = mddev->raid_disks;
3706         info.md_minor      = mddev->md_minor;
3707         info.not_persistent= !mddev->persistent;
3708
3709         info.utime         = mddev->utime;
3710         info.state         = 0;
3711         if (mddev->in_sync)
3712                 info.state = (1<<MD_SB_CLEAN);
3713         if (mddev->bitmap && mddev->bitmap_offset)
3714                 info.state = (1<<MD_SB_BITMAP_PRESENT);
3715         info.active_disks  = active;
3716         info.working_disks = working;
3717         info.failed_disks  = failed;
3718         info.spare_disks   = spare;
3719
3720         info.layout        = mddev->layout;
3721         info.chunk_size    = mddev->chunk_size;
3722
3723         if (copy_to_user(arg, &info, sizeof(info)))
3724                 return -EFAULT;
3725
3726         return 0;
3727 }
3728
3729 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
3730 {
3731         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
3732         char *ptr, *buf = NULL;
3733         int err = -ENOMEM;
3734
3735         md_allow_write(mddev);
3736
3737         file = kmalloc(sizeof(*file), GFP_KERNEL);
3738         if (!file)
3739                 goto out;
3740
3741         /* bitmap disabled, zero the first byte and copy out */
3742         if (!mddev->bitmap || !mddev->bitmap->file) {
3743                 file->pathname[0] = '\0';
3744                 goto copy_out;
3745         }
3746
3747         buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
3748         if (!buf)
3749                 goto out;
3750
3751         ptr = file_path(mddev->bitmap->file, buf, sizeof(file->pathname));
3752         if (!ptr)
3753                 goto out;
3754
3755         strcpy(file->pathname, ptr);
3756
3757 copy_out:
3758         err = 0;
3759         if (copy_to_user(arg, file, sizeof(*file)))
3760                 err = -EFAULT;
3761 out:
3762         kfree(buf);
3763         kfree(file);
3764         return err;
3765 }
3766
3767 static int get_disk_info(mddev_t * mddev, void __user * arg)
3768 {
3769         mdu_disk_info_t info;
3770         unsigned int nr;
3771         mdk_rdev_t *rdev;
3772
3773         if (copy_from_user(&info, arg, sizeof(info)))
3774                 return -EFAULT;
3775
3776         nr = info.number;
3777
3778         rdev = find_rdev_nr(mddev, nr);
3779         if (rdev) {
3780                 info.major = MAJOR(rdev->bdev->bd_dev);
3781                 info.minor = MINOR(rdev->bdev->bd_dev);
3782                 info.raid_disk = rdev->raid_disk;
3783                 info.state = 0;
3784                 if (test_bit(Faulty, &rdev->flags))
3785                         info.state |= (1<<MD_DISK_FAULTY);
3786                 else if (test_bit(In_sync, &rdev->flags)) {
3787                         info.state |= (1<<MD_DISK_ACTIVE);
3788                         info.state |= (1<<MD_DISK_SYNC);
3789                 }
3790                 if (test_bit(WriteMostly, &rdev->flags))
3791                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
3792         } else {
3793                 info.major = info.minor = 0;
3794                 info.raid_disk = -1;
3795                 info.state = (1<<MD_DISK_REMOVED);
3796         }
3797
3798         if (copy_to_user(arg, &info, sizeof(info)))
3799                 return -EFAULT;
3800
3801         return 0;
3802 }
3803
3804 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
3805 {
3806         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
3807         mdk_rdev_t *rdev;
3808         dev_t dev = MKDEV(info->major,info->minor);
3809
3810         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
3811                 return -EOVERFLOW;
3812
3813         if (!mddev->raid_disks) {
3814                 int err;
3815                 /* expecting a device which has a superblock */
3816                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
3817                 if (IS_ERR(rdev)) {
3818                         printk(KERN_WARNING 
3819                                 "md: md_import_device returned %ld\n",
3820                                 PTR_ERR(rdev));
3821                         return PTR_ERR(rdev);
3822                 }
3823                 if (!list_empty(&mddev->disks)) {
3824                         mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3825                                                         mdk_rdev_t, same_set);
3826                         int err = super_types[mddev->major_version]
3827                                 .load_super(rdev, rdev0, mddev->minor_version);
3828                         if (err < 0) {
3829                                 printk(KERN_WARNING 
3830                                         "md: %s has different UUID to %s\n",
3831                                         bdevname(rdev->bdev,b), 
3832                                         bdevname(rdev0->bdev,b2));
3833                                 export_rdev(rdev);
3834                                 return -EINVAL;
3835                         }
3836                 }
3837                 err = bind_rdev_to_array(rdev, mddev);
3838                 if (err)
3839                         export_rdev(rdev);
3840                 return err;
3841         }
3842
3843         /*
3844          * add_new_disk can be used once the array is assembled
3845          * to add "hot spares".  They must already have a superblock
3846          * written
3847          */
3848         if (mddev->pers) {
3849                 int err;
3850                 if (!mddev->pers->hot_add_disk) {
3851                         printk(KERN_WARNING 
3852                                 "%s: personality does not support diskops!\n",
3853                                mdname(mddev));
3854                         return -EINVAL;
3855                 }
3856                 if (mddev->persistent)
3857                         rdev = md_import_device(dev, mddev->major_version,
3858                                                 mddev->minor_version);
3859                 else
3860                         rdev = md_import_device(dev, -1, -1);
3861                 if (IS_ERR(rdev)) {
3862                         printk(KERN_WARNING 
3863                                 "md: md_import_device returned %ld\n",
3864                                 PTR_ERR(rdev));
3865                         return PTR_ERR(rdev);
3866                 }
3867                 /* set save_raid_disk if appropriate */
3868                 if (!mddev->persistent) {
3869                         if (info->state & (1<<MD_DISK_SYNC)  &&
3870                             info->raid_disk < mddev->raid_disks)
3871                                 rdev->raid_disk = info->raid_disk;
3872                         else
3873                                 rdev->raid_disk = -1;
3874                 } else
3875                         super_types[mddev->major_version].
3876                                 validate_super(mddev, rdev);
3877                 rdev->saved_raid_disk = rdev->raid_disk;
3878
3879                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
3880                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3881                         set_bit(WriteMostly, &rdev->flags);
3882
3883                 rdev->raid_disk = -1;
3884                 err = bind_rdev_to_array(rdev, mddev);
3885                 if (!err && !mddev->pers->hot_remove_disk) {
3886                         /* If there is hot_add_disk but no hot_remove_disk
3887                          * then added disks for geometry changes,
3888                          * and should be added immediately.
3889                          */
3890                         super_types[mddev->major_version].
3891                                 validate_super(mddev, rdev);
3892                         err = mddev->pers->hot_add_disk(mddev, rdev);
3893                         if (err)
3894                                 unbind_rdev_from_array(rdev);
3895                 }
3896                 if (err)
3897                         export_rdev(rdev);
3898
3899                 md_update_sb(mddev, 1);
3900                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3901                 md_wakeup_thread(mddev->thread);
3902                 return err;
3903         }
3904
3905         /* otherwise, add_new_disk is only allowed
3906          * for major_version==0 superblocks
3907          */
3908         if (mddev->major_version != 0) {
3909                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
3910                        mdname(mddev));
3911                 return -EINVAL;
3912         }
3913
3914         if (!(info->state & (1<<MD_DISK_FAULTY))) {
3915                 int err;
3916                 rdev = md_import_device (dev, -1, 0);
3917                 if (IS_ERR(rdev)) {
3918                         printk(KERN_WARNING 
3919                                 "md: error, md_import_device() returned %ld\n",
3920                                 PTR_ERR(rdev));
3921                         return PTR_ERR(rdev);
3922                 }
3923                 rdev->desc_nr = info->number;
3924                 if (info->raid_disk < mddev->raid_disks)
3925                         rdev->raid_disk = info->raid_disk;
3926                 else
3927                         rdev->raid_disk = -1;
3928
3929                 rdev->flags = 0;
3930
3931                 if (rdev->raid_disk < mddev->raid_disks)
3932                         if (info->state & (1<<MD_DISK_SYNC))
3933                                 set_bit(In_sync, &rdev->flags);
3934
3935                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3936                         set_bit(WriteMostly, &rdev->flags);
3937
3938                 if (!mddev->persistent) {
3939                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
3940                         rdev->sb_offset = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
3941                 } else 
3942                         rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
3943                 rdev->size = calc_dev_size(rdev, mddev->chunk_size);
3944
3945                 err = bind_rdev_to_array(rdev, mddev);
3946                 if (err) {
3947                         export_rdev(rdev);
3948                         return err;
3949                 }
3950         }
3951
3952         return 0;
3953 }
3954
3955 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
3956 {
3957         char b[BDEVNAME_SIZE];
3958         mdk_rdev_t *rdev;
3959
3960         if (!mddev->pers)
3961                 return -ENODEV;
3962
3963         rdev = find_rdev(mddev, dev);
3964         if (!rdev)
3965                 return -ENXIO;
3966
3967         if (rdev->raid_disk >= 0)
3968                 goto busy;
3969
3970         kick_rdev_from_array(rdev);
3971         md_update_sb(mddev, 1);
3972         md_new_event(mddev);
3973
3974         return 0;
3975 busy:
3976         printk(KERN_WARNING "md: cannot remove active disk %s from %s ... \n",
3977                 bdevname(rdev->bdev,b), mdname(mddev));
3978         return -EBUSY;
3979 }
3980
3981 static int hot_add_disk(mddev_t * mddev, dev_t dev)
3982 {
3983         char b[BDEVNAME_SIZE];
3984         int err;
3985         unsigned int size;
3986         mdk_rdev_t *rdev;
3987
3988         if (!mddev->pers)
3989                 return -ENODEV;
3990
3991         if (mddev->major_version != 0) {
3992                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
3993                         " version-0 superblocks.\n",
3994                         mdname(mddev));
3995                 return -EINVAL;
3996         }
3997         if (!mddev->pers->hot_add_disk) {
3998                 printk(KERN_WARNING 
3999                         "%s: personality does not support diskops!\n",
4000                         mdname(mddev));
4001                 return -EINVAL;
4002         }
4003
4004         rdev = md_import_device (dev, -1, 0);
4005         if (IS_ERR(rdev)) {
4006                 printk(KERN_WARNING 
4007                         "md: error, md_import_device() returned %ld\n",
4008                         PTR_ERR(rdev));
4009                 return -EINVAL;
4010         }
4011
4012         if (mddev->persistent)
4013                 rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
4014         else
4015                 rdev->sb_offset =
4016                         rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
4017
4018         size = calc_dev_size(rdev, mddev->chunk_size);
4019         rdev->size = size;
4020
4021         if (test_bit(Faulty, &rdev->flags)) {
4022                 printk(KERN_WARNING 
4023                         "md: can not hot-add faulty %s disk to %s!\n",
4024                         bdevname(rdev->bdev,b), mdname(mddev));
4025                 err = -EINVAL;
4026                 goto abort_export;
4027         }
4028         clear_bit(In_sync, &rdev->flags);
4029         rdev->desc_nr = -1;
4030         rdev->saved_raid_disk = -1;
4031         err = bind_rdev_to_array(rdev, mddev);
4032         if (err)
4033                 goto abort_export;
4034
4035         /*
4036          * The rest should better be atomic, we can have disk failures
4037          * noticed in interrupt contexts ...
4038          */
4039
4040         if (rdev->desc_nr == mddev->max_disks) {
4041                 printk(KERN_WARNING "%s: can not hot-add to full array!\n",
4042                         mdname(mddev));
4043                 err = -EBUSY;
4044                 goto abort_unbind_export;
4045         }
4046
4047         rdev->raid_disk = -1;
4048
4049         md_update_sb(mddev, 1);
4050
4051         /*
4052          * Kick recovery, maybe this spare has to be added to the
4053          * array immediately.
4054          */
4055         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4056         md_wakeup_thread(mddev->thread);
4057         md_new_event(mddev);
4058         return 0;
4059
4060 abort_unbind_export:
4061         unbind_rdev_from_array(rdev);
4062
4063 abort_export:
4064         export_rdev(rdev);
4065         return err;
4066 }
4067
4068 static int set_bitmap_file(mddev_t *mddev, int fd)
4069 {
4070         int err;
4071
4072         if (mddev->pers) {
4073                 if (!mddev->pers->quiesce)
4074                         return -EBUSY;
4075                 if (mddev->recovery || mddev->sync_thread)
4076                         return -EBUSY;
4077                 /* we should be able to change the bitmap.. */
4078         }
4079
4080
4081         if (fd >= 0) {
4082                 if (mddev->bitmap)
4083                         return -EEXIST; /* cannot add when bitmap is present */
4084                 mddev->bitmap_file = fget(fd);
4085
4086                 if (mddev->bitmap_file == NULL) {
4087                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
4088                                mdname(mddev));
4089                         return -EBADF;
4090                 }
4091
4092                 err = deny_bitmap_write_access(mddev->bitmap_file);
4093                 if (err) {
4094                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
4095                                mdname(mddev));
4096                         fput(mddev->bitmap_file);
4097                         mddev->bitmap_file = NULL;
4098                         return err;
4099                 }
4100                 mddev->bitmap_offset = 0; /* file overrides offset */
4101         } else if (mddev->bitmap == NULL)
4102                 return -ENOENT; /* cannot remove what isn't there */
4103         err = 0;
4104         if (mddev->pers) {
4105                 mddev->pers->quiesce(mddev, 1);
4106                 if (fd >= 0)
4107                         err = bitmap_create(mddev);
4108                 if (fd < 0 || err) {
4109                         bitmap_destroy(mddev);
4110                         fd = -1; /* make sure to put the file */
4111                 }
4112                 mddev->pers->quiesce(mddev, 0);
4113         }
4114         if (fd < 0) {
4115                 if (mddev->bitmap_file) {
4116                         restore_bitmap_write_access(mddev->bitmap_file);
4117                         fput(mddev->bitmap_file);
4118                 }
4119                 mddev->bitmap_file = NULL;
4120         }
4121
4122         return err;
4123 }
4124
4125 /*
4126  * set_array_info is used two different ways
4127  * The original usage is when creating a new array.
4128  * In this usage, raid_disks is > 0 and it together with
4129  *  level, size, not_persistent,layout,chunksize determine the
4130  *  shape of the array.
4131  *  This will always create an array with a type-0.90.0 superblock.
4132  * The newer usage is when assembling an array.
4133  *  In this case raid_disks will be 0, and the major_version field is
4134  *  use to determine which style super-blocks are to be found on the devices.
4135  *  The minor and patch _version numbers are also kept incase the
4136  *  super_block handler wishes to interpret them.
4137  */
4138 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
4139 {
4140
4141         if (info->raid_disks == 0) {
4142                 /* just setting version number for superblock loading */
4143                 if (info->major_version < 0 ||
4144                     info->major_version >= ARRAY_SIZE(super_types) ||
4145                     super_types[info->major_version].name == NULL) {
4146                         /* maybe try to auto-load a module? */
4147                         printk(KERN_INFO 
4148                                 "md: superblock version %d not known\n",
4149                                 info->major_version);
4150                         return -EINVAL;
4151                 }
4152                 mddev->major_version = info->major_version;
4153                 mddev->minor_version = info->minor_version;
4154                 mddev->patch_version = info->patch_version;
4155                 mddev->persistent = !info->not_persistent;
4156                 return 0;
4157         }
4158         mddev->major_version = MD_MAJOR_VERSION;
4159         mddev->minor_version = MD_MINOR_VERSION;
4160         mddev->patch_version = MD_PATCHLEVEL_VERSION;
4161         mddev->ctime         = get_seconds();
4162
4163         mddev->level         = info->level;
4164         mddev->clevel[0]     = 0;
4165         mddev->size          = info->size;
4166         mddev->raid_disks    = info->raid_disks;
4167         /* don't set md_minor, it is determined by which /dev/md* was
4168          * openned
4169          */
4170         if (info->state & (1<<MD_SB_CLEAN))
4171                 mddev->recovery_cp = MaxSector;
4172         else
4173                 mddev->recovery_cp = 0;
4174         mddev->persistent    = ! info->not_persistent;
4175
4176         mddev->layout        = info->layout;
4177         mddev->chunk_size    = info->chunk_size;
4178
4179         mddev->max_disks     = MD_SB_DISKS;
4180
4181         mddev->flags         = 0;
4182         set_bit(MD_CHANGE_DEVS, &mddev->flags);
4183
4184         mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
4185         mddev->bitmap_offset = 0;
4186
4187         mddev->reshape_position = MaxSector;
4188
4189         /*
4190          * Generate a 128 bit UUID
4191          */
4192         get_random_bytes(mddev->uuid, 16);
4193
4194         mddev->new_level = mddev->level;
4195         mddev->new_chunk = mddev->chunk_size;
4196         mddev->new_layout = mddev->layout;
4197         mddev->delta_disks = 0;
4198
4199         return 0;
4200 }
4201
4202 static int update_size(mddev_t *mddev, unsigned long size)
4203 {
4204         mdk_rdev_t * rdev;
4205         int rv;
4206         struct list_head *tmp;
4207         int fit = (size == 0);
4208
4209         if (mddev->pers->resize == NULL)
4210                 return -EINVAL;
4211         /* The "size" is the amount of each device that is used.
4212          * This can only make sense for arrays with redundancy.
4213          * linear and raid0 always use whatever space is available
4214          * We can only consider changing the size if no resync
4215          * or reconstruction is happening, and if the new size
4216          * is acceptable. It must fit before the sb_offset or,
4217          * if that is <data_offset, it must fit before the
4218          * size of each device.
4219          * If size is zero, we find the largest size that fits.
4220          */
4221         if (mddev->sync_thread)
4222                 return -EBUSY;
4223         ITERATE_RDEV(mddev,rdev,tmp) {
4224                 sector_t avail;
4225                 avail = rdev->size * 2;
4226
4227                 if (fit && (size == 0 || size > avail/2))
4228                         size = avail/2;
4229                 if (avail < ((sector_t)size << 1))
4230                         return -ENOSPC;
4231         }
4232         rv = mddev->pers->resize(mddev, (sector_t)size *2);
4233         if (!rv) {
4234                 struct block_device *bdev;
4235
4236                 bdev = bdget_disk(mddev->gendisk, 0);
4237                 if (bdev) {
4238                         mutex_lock(&bdev->bd_inode->i_mutex);
4239                         i_size_write(bdev->bd_inode, (loff_t)mddev->array_size << 10);
4240                         mutex_unlock(&bdev->bd_inode->i_mutex);
4241                         bdput(bdev);
4242                 }
4243         }
4244         return rv;
4245 }
4246
4247 static int update_raid_disks(mddev_t *mddev, int raid_disks)
4248 {
4249         int rv;
4250         /* change the number of raid disks */
4251         if (mddev->pers->check_reshape == NULL)
4252                 return -EINVAL;
4253         if (raid_disks <= 0 ||
4254             raid_disks >= mddev->max_disks)
4255                 return -EINVAL;
4256         if (mddev->sync_thread || mddev->reshape_position != MaxSector)
4257                 return -EBUSY;
4258         mddev->delta_disks = raid_disks - mddev->raid_disks;
4259
4260         rv = mddev->pers->check_reshape(mddev);
4261         return rv;
4262 }
4263
4264
4265 /*
4266  * update_array_info is used to change the configuration of an
4267  * on-line array.
4268  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
4269  * fields in the info are checked against the array.
4270  * Any differences that cannot be handled will cause an error.
4271  * Normally, only one change can be managed at a time.
4272  */
4273 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
4274 {
4275         int rv = 0;
4276         int cnt = 0;
4277         int state = 0;
4278
4279         /* calculate expected state,ignoring low bits */
4280         if (mddev->bitmap && mddev->bitmap_offset)
4281                 state |= (1 << MD_SB_BITMAP_PRESENT);
4282
4283         if (mddev->major_version != info->major_version ||
4284             mddev->minor_version != info->minor_version ||
4285 /*          mddev->patch_version != info->patch_version || */
4286             mddev->ctime         != info->ctime         ||
4287             mddev->level         != info->level         ||
4288 /*          mddev->layout        != info->layout        || */
4289             !mddev->persistent   != info->not_persistent||
4290             mddev->chunk_size    != info->chunk_size    ||
4291             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
4292             ((state^info->state) & 0xfffffe00)
4293                 )
4294                 return -EINVAL;
4295         /* Check there is only one change */
4296         if (info->size >= 0 && mddev->size != info->size) cnt++;
4297         if (mddev->raid_disks != info->raid_disks) cnt++;
4298         if (mddev->layout != info->layout) cnt++;
4299         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
4300         if (cnt == 0) return 0;
4301         if (cnt > 1) return -EINVAL;
4302
4303         if (mddev->layout != info->layout) {
4304                 /* Change layout
4305                  * we don't need to do anything at the md level, the
4306                  * personality will take care of it all.
4307                  */
4308                 if (mddev->pers->reconfig == NULL)
4309                         return -EINVAL;
4310                 else
4311                         return mddev->pers->reconfig(mddev, info->layout, -1);
4312         }
4313         if (info->size >= 0 && mddev->size != info->size)
4314                 rv = update_size(mddev, info->size);
4315
4316         if (mddev->raid_disks    != info->raid_disks)
4317                 rv = update_raid_disks(mddev, info->raid_disks);
4318
4319         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
4320                 if (mddev->pers->quiesce == NULL)
4321                         return -EINVAL;
4322                 if (mddev->recovery || mddev->sync_thread)
4323                         return -EBUSY;
4324                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
4325                         /* add the bitmap */
4326                         if (mddev->bitmap)
4327                                 return -EEXIST;
4328                         if (mddev->default_bitmap_offset == 0)
4329                                 return -EINVAL;
4330                         mddev->bitmap_offset = mddev->default_bitmap_offset;
4331                         mddev->pers->quiesce(mddev, 1);
4332                         rv = bitmap_create(mddev);
4333                         if (rv)
4334                                 bitmap_destroy(mddev);
4335                         mddev->pers->quiesce(mddev, 0);
4336                 } else {
4337                         /* remove the bitmap */
4338                         if (!mddev->bitmap)
4339                                 return -ENOENT;
4340                         if (mddev->bitmap->file)
4341                                 return -EINVAL;
4342                         mddev->pers->quiesce(mddev, 1);
4343                         bitmap_destroy(mddev);
4344                         mddev->pers->quiesce(mddev, 0);
4345                         mddev->bitmap_offset = 0;
4346                 }
4347         }
4348         md_update_sb(mddev, 1);
4349         return rv;
4350 }
4351
4352 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
4353 {
4354         mdk_rdev_t *rdev;
4355
4356         if (mddev->pers == NULL)
4357                 return -ENODEV;
4358
4359         rdev = find_rdev(mddev, dev);
4360         if (!rdev)
4361                 return -ENODEV;
4362
4363         md_error(mddev, rdev);
4364         return 0;
4365 }
4366
4367 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
4368 {
4369         mddev_t *mddev = bdev->bd_disk->private_data;
4370
4371         geo->heads = 2;
4372         geo->sectors = 4;
4373         geo->cylinders = get_capacity(mddev->gendisk) / 8;
4374         return 0;
4375 }
4376
4377 static int md_ioctl(struct inode *inode, struct file *file,
4378                         unsigned int cmd, unsigned long arg)
4379 {
4380         int err = 0;
4381         void __user *argp = (void __user *)arg;
4382         mddev_t *mddev = NULL;
4383
4384         if (!capable(CAP_SYS_ADMIN))
4385                 return -EACCES;
4386
4387         /*
4388          * Commands dealing with the RAID driver but not any
4389          * particular array:
4390          */
4391         switch (cmd)
4392         {
4393                 case RAID_VERSION:
4394                         err = get_version(argp);
4395                         goto done;
4396
4397                 case PRINT_RAID_DEBUG:
4398                         err = 0;
4399                         md_print_devices();
4400                         goto done;
4401
4402 #ifndef MODULE
4403                 case RAID_AUTORUN:
4404                         err = 0;
4405                         autostart_arrays(arg);
4406                         goto done;
4407 #endif
4408                 default:;
4409         }
4410
4411         /*
4412          * Commands creating/starting a new array:
4413          */
4414
4415         mddev = inode->i_bdev->bd_disk->private_data;
4416
4417         if (!mddev) {
4418                 BUG();
4419                 goto abort;
4420         }
4421
4422         err = mddev_lock(mddev);
4423         if (err) {
4424                 printk(KERN_INFO 
4425                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
4426                         err, cmd);
4427                 goto abort;
4428         }
4429
4430         switch (cmd)
4431         {
4432                 case SET_ARRAY_INFO:
4433                         {
4434                                 mdu_array_info_t info;
4435                                 if (!arg)
4436                                         memset(&info, 0, sizeof(info));
4437                                 else if (copy_from_user(&info, argp, sizeof(info))) {
4438                                         err = -EFAULT;
4439                                         goto abort_unlock;
4440                                 }
4441                                 if (mddev->pers) {
4442                                         err = update_array_info(mddev, &info);
4443                                         if (err) {
4444                                                 printk(KERN_WARNING "md: couldn't update"
4445                                                        " array info. %d\n", err);
4446                                                 goto abort_unlock;
4447                                         }
4448                                         goto done_unlock;
4449                                 }
4450                                 if (!list_empty(&mddev->disks)) {
4451                                         printk(KERN_WARNING
4452                                                "md: array %s already has disks!\n",
4453                                                mdname(mddev));
4454                                         err = -EBUSY;
4455                                         goto abort_unlock;
4456                                 }
4457                                 if (mddev->raid_disks) {
4458                                         printk(KERN_WARNING
4459                                                "md: array %s already initialised!\n",
4460                                                mdname(mddev));
4461                                         err = -EBUSY;
4462                                         goto abort_unlock;
4463                                 }
4464                                 err = set_array_info(mddev, &info);
4465                                 if (err) {
4466                                         printk(KERN_WARNING "md: couldn't set"
4467                                                " array info. %d\n", err);
4468                                         goto abort_unlock;
4469                                 }
4470                         }
4471                         goto done_unlock;
4472
4473                 default:;
4474         }
4475
4476         /*
4477          * Commands querying/configuring an existing array:
4478          */
4479         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
4480          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
4481         if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
4482                         && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
4483                         && cmd != GET_BITMAP_FILE) {
4484                 err = -ENODEV;
4485                 goto abort_unlock;
4486         }
4487
4488         /*
4489          * Commands even a read-only array can execute:
4490          */
4491         switch (cmd)
4492         {
4493                 case GET_ARRAY_INFO:
4494                         err = get_array_info(mddev, argp);
4495                         goto done_unlock;
4496
4497                 case GET_BITMAP_FILE:
4498                         err = get_bitmap_file(mddev, argp);
4499                         goto done_unlock;
4500
4501                 case GET_DISK_INFO:
4502                         err = get_disk_info(mddev, argp);
4503                         goto done_unlock;
4504
4505                 case RESTART_ARRAY_RW:
4506                         err = restart_array(mddev);
4507                         goto done_unlock;
4508
4509                 case STOP_ARRAY:
4510                         err = do_md_stop (mddev, 0);
4511                         goto done_unlock;
4512
4513                 case STOP_ARRAY_RO:
4514                         err = do_md_stop (mddev, 1);
4515                         goto done_unlock;
4516
4517         /*
4518          * We have a problem here : there is no easy way to give a CHS
4519          * virtual geometry. We currently pretend that we have a 2 heads
4520          * 4 sectors (with a BIG number of cylinders...). This drives
4521          * dosfs just mad... ;-)
4522          */
4523         }
4524
4525         /*
4526          * The remaining ioctls are changing the state of the
4527          * superblock, so we do not allow them on read-only arrays.
4528          * However non-MD ioctls (e.g. get-size) will still come through
4529          * here and hit the 'default' below, so only disallow
4530          * 'md' ioctls, and switch to rw mode if started auto-readonly.
4531          */
4532         if (_IOC_TYPE(cmd) == MD_MAJOR &&
4533             mddev->ro && mddev->pers) {
4534                 if (mddev->ro == 2) {
4535                         mddev->ro = 0;
4536                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4537                 md_wakeup_thread(mddev->thread);
4538
4539                 } else {
4540                         err = -EROFS;
4541                         goto abort_unlock;
4542                 }
4543         }
4544
4545         switch (cmd)
4546         {
4547                 case ADD_NEW_DISK:
4548                 {
4549                         mdu_disk_info_t info;
4550                         if (copy_from_user(&info, argp, sizeof(info)))
4551                                 err = -EFAULT;
4552                         else
4553                                 err = add_new_disk(mddev, &info);
4554                         goto done_unlock;
4555                 }
4556
4557                 case HOT_REMOVE_DISK:
4558                         err = hot_remove_disk(mddev, new_decode_dev(arg));
4559                         goto done_unlock;
4560
4561                 case HOT_ADD_DISK:
4562                         err = hot_add_disk(mddev, new_decode_dev(arg));
4563                         goto done_unlock;
4564
4565                 case SET_DISK_FAULTY:
4566                         err = set_disk_faulty(mddev, new_decode_dev(arg));
4567                         goto done_unlock;
4568
4569                 case RUN_ARRAY:
4570                         err = do_md_run (mddev);
4571                         goto done_unlock;
4572
4573                 case SET_BITMAP_FILE:
4574                         err = set_bitmap_file(mddev, (int)arg);
4575                         goto done_unlock;
4576
4577                 default:
4578                         err = -EINVAL;
4579                         goto abort_unlock;
4580         }
4581
4582 done_unlock:
4583 abort_unlock:
4584         mddev_unlock(mddev);
4585
4586         return err;
4587 done:
4588         if (err)
4589                 MD_BUG();
4590 abort:
4591         return err;
4592 }
4593
4594 static int md_open(struct inode *inode, struct file *file)
4595 {
4596         /*
4597          * Succeed if we can lock the mddev, which confirms that
4598          * it isn't being stopped right now.
4599          */
4600         mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
4601         int err;
4602
4603         if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
4604                 goto out;
4605
4606         err = 0;
4607         mddev_get(mddev);
4608         mddev_unlock(mddev);
4609
4610         check_disk_change(inode->i_bdev);
4611  out:
4612         return err;
4613 }
4614
4615 static int md_release(struct inode *inode, struct file * file)
4616 {
4617         mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
4618
4619         BUG_ON(!mddev);
4620         mddev_put(mddev);
4621
4622         return 0;
4623 }
4624
4625 static int md_media_changed(struct gendisk *disk)
4626 {
4627         mddev_t *mddev = disk->private_data;
4628
4629         return mddev->changed;
4630 }
4631
4632 static int md_revalidate(struct gendisk *disk)
4633 {
4634         mddev_t *mddev = disk->private_data;
4635
4636         mddev->changed = 0;
4637         return 0;
4638 }
4639 static struct block_device_operations md_fops =
4640 {
4641         .owner          = THIS_MODULE,
4642         .open           = md_open,
4643         .release        = md_release,
4644         .ioctl          = md_ioctl,
4645         .getgeo         = md_getgeo,
4646         .media_changed  = md_media_changed,
4647         .revalidate_disk= md_revalidate,
4648 };
4649
4650 static int md_thread(void * arg)
4651 {
4652         mdk_thread_t *thread = arg;
4653
4654         /*
4655          * md_thread is a 'system-thread', it's priority should be very
4656          * high. We avoid resource deadlocks individually in each
4657          * raid personality. (RAID5 does preallocation) We also use RR and
4658          * the very same RT priority as kswapd, thus we will never get
4659          * into a priority inversion deadlock.
4660          *
4661          * we definitely have to have equal or higher priority than
4662          * bdflush, otherwise bdflush will deadlock if there are too
4663          * many dirty RAID5 blocks.
4664          */
4665
4666         allow_signal(SIGKILL);
4667         while (!kthread_should_stop()) {
4668
4669                 /* We need to wait INTERRUPTIBLE so that
4670                  * we don't add to the load-average.
4671                  * That means we need to be sure no signals are
4672                  * pending
4673                  */
4674                 if (signal_pending(current))
4675                         flush_signals(current);
4676
4677                 wait_event_interruptible_timeout
4678                         (thread->wqueue,
4679                          test_bit(THREAD_WAKEUP, &thread->flags)
4680                          || kthread_should_stop(),
4681                          thread->timeout);
4682
4683                 clear_bit(THREAD_WAKEUP, &thread->flags);
4684
4685                 thread->run(thread->mddev);
4686         }
4687
4688         return 0;
4689 }
4690
4691 void md_wakeup_thread(mdk_thread_t *thread)
4692 {
4693         if (thread) {
4694                 dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
4695                 set_bit(THREAD_WAKEUP, &thread->flags);
4696                 wake_up(&thread->wqueue);
4697         }
4698 }
4699
4700 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
4701                                  const char *name)
4702 {
4703         mdk_thread_t *thread;
4704
4705         thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
4706         if (!thread)
4707                 return NULL;
4708
4709         init_waitqueue_head(&thread->wqueue);
4710
4711         thread->run = run;
4712         thread->mddev = mddev;
4713         thread->timeout = MAX_SCHEDULE_TIMEOUT;
4714         thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
4715         if (IS_ERR(thread->tsk)) {
4716                 kfree(thread);
4717                 return NULL;
4718         }
4719         return thread;
4720 }
4721
4722 void md_unregister_thread(mdk_thread_t *thread)
4723 {
4724         dprintk("interrupting MD-thread pid %d\n", thread->tsk->pid);
4725
4726         kthread_stop(thread->tsk);
4727         kfree(thread);
4728 }
4729
4730 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
4731 {
4732         if (!mddev) {
4733                 MD_BUG();
4734                 return;
4735         }
4736
4737         if (!rdev || test_bit(Faulty, &rdev->flags))
4738                 return;
4739 /*
4740         dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
4741                 mdname(mddev),
4742                 MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
4743                 __builtin_return_address(0),__builtin_return_address(1),
4744                 __builtin_return_address(2),__builtin_return_address(3));
4745 */
4746         if (!mddev->pers)
4747                 return;
4748         if (!mddev->pers->error_handler)
4749                 return;
4750         mddev->pers->error_handler(mddev,rdev);
4751         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4752         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4753         md_wakeup_thread(mddev->thread);
4754         md_new_event_inintr(mddev);
4755 }
4756
4757 /* seq_file implementation /proc/mdstat */
4758
4759 static void status_unused(struct seq_file *seq)
4760 {
4761         int i = 0;
4762         mdk_rdev_t *rdev;
4763         struct list_head *tmp;
4764
4765         seq_printf(seq, "unused devices: ");
4766
4767         ITERATE_RDEV_PENDING(rdev,tmp) {
4768                 char b[BDEVNAME_SIZE];
4769                 i++;
4770                 seq_printf(seq, "%s ",
4771                               bdevname(rdev->bdev,b));
4772         }
4773         if (!i)
4774                 seq_printf(seq, "<none>");
4775
4776         seq_printf(seq, "\n");
4777 }
4778
4779
4780 static void status_resync(struct seq_file *seq, mddev_t * mddev)
4781 {
4782         sector_t max_blocks, resync, res;
4783         unsigned long dt, db, rt;
4784         int scale;
4785         unsigned int per_milli;
4786
4787         resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
4788
4789         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4790                 max_blocks = mddev->resync_max_sectors >> 1;
4791         else
4792                 max_blocks = mddev->size;
4793
4794         /*
4795          * Should not happen.
4796          */
4797         if (!max_blocks) {
4798                 MD_BUG();
4799                 return;
4800         }
4801         /* Pick 'scale' such that (resync>>scale)*1000 will fit
4802          * in a sector_t, and (max_blocks>>scale) will fit in a
4803          * u32, as those are the requirements for sector_div.
4804          * Thus 'scale' must be at least 10
4805          */
4806         scale = 10;
4807         if (sizeof(sector_t) > sizeof(unsigned long)) {
4808                 while ( max_blocks/2 > (1ULL<<(scale+32)))
4809                         scale++;
4810         }
4811         res = (resync>>scale)*1000;
4812         sector_div(res, (u32)((max_blocks>>scale)+1));
4813
4814         per_milli = res;
4815         {
4816                 int i, x = per_milli/50, y = 20-x;
4817                 seq_printf(seq, "[");
4818                 for (i = 0; i < x; i++)
4819                         seq_printf(seq, "=");
4820                 seq_printf(seq, ">");
4821                 for (i = 0; i < y; i++)
4822                         seq_printf(seq, ".");
4823                 seq_printf(seq, "] ");
4824         }
4825         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
4826                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
4827                     "reshape" :
4828                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
4829                      "check" :
4830                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
4831                       "resync" : "recovery"))),
4832                    per_milli/10, per_milli % 10,
4833                    (unsigned long long) resync,
4834                    (unsigned long long) max_blocks);
4835
4836         /*
4837          * We do not want to overflow, so the order of operands and
4838          * the * 100 / 100 trick are important. We do a +1 to be
4839          * safe against division by zero. We only estimate anyway.
4840          *
4841          * dt: time from mark until now
4842          * db: blocks written from mark until now
4843          * rt: remaining time
4844          */
4845         dt = ((jiffies - mddev->resync_mark) / HZ);
4846         if (!dt) dt++;
4847         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
4848                 - mddev->resync_mark_cnt;
4849         rt = (dt * ((unsigned long)(max_blocks-resync) / (db/2/100+1)))/100;
4850
4851         seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
4852
4853         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
4854 }
4855
4856 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
4857 {
4858         struct list_head *tmp;
4859         loff_t l = *pos;
4860         mddev_t *mddev;
4861
4862         if (l >= 0x10000)
4863                 return NULL;
4864         if (!l--)
4865                 /* header */
4866                 return (void*)1;
4867
4868         spin_lock(&all_mddevs_lock);
4869         list_for_each(tmp,&all_mddevs)
4870                 if (!l--) {
4871                         mddev = list_entry(tmp, mddev_t, all_mddevs);
4872                         mddev_get(mddev);
4873                         spin_unlock(&all_mddevs_lock);
4874                         return mddev;
4875                 }
4876         spin_unlock(&all_mddevs_lock);
4877         if (!l--)
4878                 return (void*)2;/* tail */
4879         return NULL;
4880 }
4881
4882 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4883 {
4884         struct list_head *tmp;
4885         mddev_t *next_mddev, *mddev = v;
4886         
4887         ++*pos;
4888         if (v == (void*)2)
4889                 return NULL;
4890
4891         spin_lock(&all_mddevs_lock);
4892         if (v == (void*)1)
4893                 tmp = all_mddevs.next;
4894         else
4895                 tmp = mddev->all_mddevs.next;
4896         if (tmp != &all_mddevs)
4897                 next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
4898         else {
4899                 next_mddev = (void*)2;
4900                 *pos = 0x10000;
4901         }               
4902         spin_unlock(&all_mddevs_lock);
4903
4904         if (v != (void*)1)
4905                 mddev_put(mddev);
4906         return next_mddev;
4907
4908 }
4909
4910 static void md_seq_stop(struct seq_file *seq, void *v)
4911 {
4912         mddev_t *mddev = v;
4913
4914         if (mddev && v != (void*)1 && v != (void*)2)
4915                 mddev_put(mddev);
4916 }
4917
4918 struct mdstat_info {
4919         int event;
4920 };
4921
4922 static int md_seq_show(struct seq_file *seq, void *v)
4923 {
4924         mddev_t *mddev = v;
4925         sector_t size;
4926         struct list_head *tmp2;
4927         mdk_rdev_t *rdev;
4928         struct mdstat_info *mi = seq->private;
4929         struct bitmap *bitmap;
4930
4931         if (v == (void*)1) {
4932                 struct mdk_personality *pers;
4933                 seq_printf(seq, "Personalities : ");
4934                 spin_lock(&pers_lock);
4935                 list_for_each_entry(pers, &pers_list, list)
4936                         seq_printf(seq, "[%s] ", pers->name);
4937
4938                 spin_unlock(&pers_lock);
4939                 seq_printf(seq, "\n");
4940                 mi->event = atomic_read(&md_event_count);
4941                 return 0;
4942         }
4943         if (v == (void*)2) {
4944                 status_unused(seq);
4945                 return 0;
4946         }
4947
4948         if (mddev_lock(mddev) < 0)
4949                 return -EINTR;
4950
4951         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
4952                 seq_printf(seq, "%s : %sactive", mdname(mddev),
4953                                                 mddev->pers ? "" : "in");
4954                 if (mddev->pers) {
4955                         if (mddev->ro==1)
4956                                 seq_printf(seq, " (read-only)");
4957                         if (mddev->ro==2)
4958                                 seq_printf(seq, "(auto-read-only)");
4959                         seq_printf(seq, " %s", mddev->pers->name);
4960                 }
4961
4962                 size = 0;
4963                 ITERATE_RDEV(mddev,rdev,tmp2) {
4964                         char b[BDEVNAME_SIZE];
4965                         seq_printf(seq, " %s[%d]",
4966                                 bdevname(rdev->bdev,b), rdev->desc_nr);
4967                         if (test_bit(WriteMostly, &rdev->flags))
4968                                 seq_printf(seq, "(W)");
4969                         if (test_bit(Faulty, &rdev->flags)) {
4970                                 seq_printf(seq, "(F)");
4971                                 continue;
4972                         } else if (rdev->raid_disk < 0)
4973                                 seq_printf(seq, "(S)"); /* spare */
4974                         size += rdev->size;
4975                 }
4976
4977                 if (!list_empty(&mddev->disks)) {
4978                         if (mddev->pers)
4979                                 seq_printf(seq, "\n      %llu blocks",
4980                                         (unsigned long long)mddev->array_size);
4981                         else
4982                                 seq_printf(seq, "\n      %llu blocks",
4983                                         (unsigned long long)size);
4984                 }
4985                 if (mddev->persistent) {
4986                         if (mddev->major_version != 0 ||
4987                             mddev->minor_version != 90) {
4988                                 seq_printf(seq," super %d.%d",
4989                                            mddev->major_version,
4990                                            mddev->minor_version);
4991                         }
4992                 } else
4993                         seq_printf(seq, " super non-persistent");
4994
4995                 if (mddev->pers) {
4996                         mddev->pers->status (seq, mddev);
4997                         seq_printf(seq, "\n      ");
4998                         if (mddev->pers->sync_request) {
4999                                 if (mddev->curr_resync > 2) {
5000                                         status_resync (seq, mddev);
5001                                         seq_printf(seq, "\n      ");
5002                                 } else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
5003                                         seq_printf(seq, "\tresync=DELAYED\n      ");
5004                                 else if (mddev->recovery_cp < MaxSector)
5005                                         seq_printf(seq, "\tresync=PENDING\n      ");
5006                         }
5007                 } else
5008                         seq_printf(seq, "\n       ");
5009
5010                 if ((bitmap = mddev->bitmap)) {
5011                         unsigned long chunk_kb;
5012                         unsigned long flags;
5013                         spin_lock_irqsave(&bitmap->lock, flags);
5014                         chunk_kb = bitmap->chunksize >> 10;
5015                         seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
5016                                 "%lu%s chunk",
5017                                 bitmap->pages - bitmap->missing_pages,
5018                                 bitmap->pages,
5019                                 (bitmap->pages - bitmap->missing_pages)
5020                                         << (PAGE_SHIFT - 10),
5021                                 chunk_kb ? chunk_kb : bitmap->chunksize,
5022                                 chunk_kb ? "KB" : "B");
5023                         if (bitmap->file) {
5024                                 seq_printf(seq, ", file: ");
5025                                 seq_path(seq, bitmap->file->f_path.mnt,
5026                                          bitmap->file->f_path.dentry," \t\n");
5027                         }
5028
5029                         seq_printf(seq, "\n");
5030                         spin_unlock_irqrestore(&bitmap->lock, flags);
5031                 }
5032
5033                 seq_printf(seq, "\n");
5034         }
5035         mddev_unlock(mddev);
5036         
5037         return 0;
5038 }
5039
5040 static struct seq_operations md_seq_ops = {
5041         .start  = md_seq_start,
5042         .next   = md_seq_next,
5043         .stop   = md_seq_stop,
5044         .show   = md_seq_show,
5045 };
5046
5047 static int md_seq_open(struct inode *inode, struct file *file)
5048 {
5049         int error;
5050         struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
5051         if (mi == NULL)
5052                 return -ENOMEM;
5053
5054         error = seq_open(file, &md_seq_ops);
5055         if (error)
5056                 kfree(mi);
5057         else {
5058                 struct seq_file *p = file->private_data;
5059                 p->private = mi;
5060                 mi->event = atomic_read(&md_event_count);
5061         }
5062         return error;
5063 }
5064
5065 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
5066 {
5067         struct seq_file *m = filp->private_data;
5068         struct mdstat_info *mi = m->private;
5069         int mask;
5070
5071         poll_wait(filp, &md_event_waiters, wait);
5072
5073         /* always allow read */
5074         mask = POLLIN | POLLRDNORM;
5075
5076         if (mi->event != atomic_read(&md_event_count))
5077                 mask |= POLLERR | POLLPRI;
5078         return mask;
5079 }
5080
5081 static const struct file_operations md_seq_fops = {
5082         .owner          = THIS_MODULE,
5083         .open           = md_seq_open,
5084         .read           = seq_read,
5085         .llseek         = seq_lseek,
5086         .release        = seq_release_private,
5087         .poll           = mdstat_poll,
5088 };
5089
5090 int register_md_personality(struct mdk_personality *p)
5091 {
5092         spin_lock(&pers_lock);
5093         list_add_tail(&p->list, &pers_list);
5094         printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
5095         spin_unlock(&pers_lock);
5096         return 0;
5097 }
5098
5099 int unregister_md_personality(struct mdk_personality *p)
5100 {
5101         printk(KERN_INFO "md: %s personality unregistered\n", p->name);
5102         spin_lock(&pers_lock);
5103         list_del_init(&p->list);
5104         spin_unlock(&pers_lock);
5105         return 0;
5106 }
5107
5108 static int is_mddev_idle(mddev_t *mddev)
5109 {
5110         mdk_rdev_t * rdev;
5111         struct list_head *tmp;
5112         int idle;
5113         long curr_events;
5114
5115         idle = 1;
5116         ITERATE_RDEV(mddev,rdev,tmp) {
5117                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
5118                 curr_events = disk_stat_read(disk, sectors[0]) + 
5119                                 disk_stat_read(disk, sectors[1]) - 
5120                                 atomic_read(&disk->sync_io);
5121                 /* sync IO will cause sync_io to increase before the disk_stats
5122                  * as sync_io is counted when a request starts, and
5123                  * disk_stats is counted when it completes.
5124                  * So resync activity will cause curr_events to be smaller than
5125                  * when there was no such activity.
5126                  * non-sync IO will cause disk_stat to increase without
5127                  * increasing sync_io so curr_events will (eventually)
5128                  * be larger than it was before.  Once it becomes
5129                  * substantially larger, the test below will cause
5130                  * the array to appear non-idle, and resync will slow
5131                  * down.
5132                  * If there is a lot of outstanding resync activity when
5133                  * we set last_event to curr_events, then all that activity
5134                  * completing might cause the array to appear non-idle
5135                  * and resync will be slowed down even though there might
5136                  * not have been non-resync activity.  This will only
5137                  * happen once though.  'last_events' will soon reflect
5138                  * the state where there is little or no outstanding
5139                  * resync requests, and further resync activity will
5140                  * always make curr_events less than last_events.
5141                  *
5142                  */
5143                 if (curr_events - rdev->last_events > 4096) {
5144                         rdev->last_events = curr_events;
5145                         idle = 0;
5146                 }
5147         }
5148         return idle;
5149 }
5150
5151 void md_done_sync(mddev_t *mddev, int blocks, int ok)
5152 {
5153         /* another "blocks" (512byte) blocks have been synced */
5154         atomic_sub(blocks, &mddev->recovery_active);
5155         wake_up(&mddev->recovery_wait);
5156         if (!ok) {
5157                 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
5158                 md_wakeup_thread(mddev->thread);
5159                 // stop recovery, signal do_sync ....
5160         }
5161 }
5162
5163
5164 /* md_write_start(mddev, bi)
5165  * If we need to update some array metadata (e.g. 'active' flag
5166  * in superblock) before writing, schedule a superblock update
5167  * and wait for it to complete.
5168  */
5169 void md_write_start(mddev_t *mddev, struct bio *bi)
5170 {
5171         if (bio_data_dir(bi) != WRITE)
5172                 return;
5173
5174         BUG_ON(mddev->ro == 1);
5175         if (mddev->ro == 2) {
5176                 /* need to switch to read/write */
5177                 mddev->ro = 0;
5178                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5179                 md_wakeup_thread(mddev->thread);
5180         }
5181         atomic_inc(&mddev->writes_pending);
5182         if (mddev->in_sync) {
5183                 spin_lock_irq(&mddev->write_lock);
5184                 if (mddev->in_sync) {
5185                         mddev->in_sync = 0;
5186                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
5187                         md_wakeup_thread(mddev->thread);
5188                 }
5189                 spin_unlock_irq(&mddev->write_lock);
5190         }
5191         wait_event(mddev->sb_wait, mddev->flags==0);
5192 }
5193
5194 void md_write_end(mddev_t *mddev)
5195 {
5196         if (atomic_dec_and_test(&mddev->writes_pending)) {
5197                 if (mddev->safemode == 2)
5198                         md_wakeup_thread(mddev->thread);
5199                 else if (mddev->safemode_delay)
5200                         mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
5201         }
5202 }
5203
5204 /* md_allow_write(mddev)
5205  * Calling this ensures that the array is marked 'active' so that writes
5206  * may proceed without blocking.  It is important to call this before
5207  * attempting a GFP_KERNEL allocation while holding the mddev lock.
5208  * Must be called with mddev_lock held.
5209  */
5210 void md_allow_write(mddev_t *mddev)
5211 {
5212         if (!mddev->pers)
5213                 return;
5214         if (mddev->ro)
5215                 return;
5216
5217         spin_lock_irq(&mddev->write_lock);
5218         if (mddev->in_sync) {
5219                 mddev->in_sync = 0;
5220                 set_bit(MD_CHANGE_CLEAN, &mddev->flags);
5221                 if (mddev->safemode_delay &&
5222                     mddev->safemode == 0)
5223                         mddev->safemode = 1;
5224                 spin_unlock_irq(&mddev->write_lock);
5225                 md_update_sb(mddev, 0);
5226         } else
5227                 spin_unlock_irq(&mddev->write_lock);
5228 }
5229 EXPORT_SYMBOL_GPL(md_allow_write);
5230
5231 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
5232
5233 #define SYNC_MARKS      10
5234 #define SYNC_MARK_STEP  (3*HZ)
5235 void md_do_sync(mddev_t *mddev)
5236 {
5237         mddev_t *mddev2;
5238         unsigned int currspeed = 0,
5239                  window;
5240         sector_t max_sectors,j, io_sectors;
5241         unsigned long mark[SYNC_MARKS];
5242         sector_t mark_cnt[SYNC_MARKS];
5243         int last_mark,m;
5244         struct list_head *tmp;
5245         sector_t last_check;
5246         int skipped = 0;
5247         struct list_head *rtmp;
5248         mdk_rdev_t *rdev;
5249         char *desc;
5250
5251         /* just incase thread restarts... */
5252         if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
5253                 return;
5254         if (mddev->ro) /* never try to sync a read-only array */
5255                 return;
5256
5257         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5258                 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
5259                         desc = "data-check";
5260                 else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
5261                         desc = "requested-resync";
5262                 else
5263                         desc = "resync";
5264         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5265                 desc = "reshape";
5266         else
5267                 desc = "recovery";
5268
5269         /* we overload curr_resync somewhat here.
5270          * 0 == not engaged in resync at all
5271          * 2 == checking that there is no conflict with another sync
5272          * 1 == like 2, but have yielded to allow conflicting resync to
5273          *              commense
5274          * other == active in resync - this many blocks
5275          *
5276          * Before starting a resync we must have set curr_resync to
5277          * 2, and then checked that every "conflicting" array has curr_resync
5278          * less than ours.  When we find one that is the same or higher
5279          * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
5280          * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
5281          * This will mean we have to start checking from the beginning again.
5282          *
5283          */
5284
5285         do {
5286                 mddev->curr_resync = 2;
5287
5288         try_again:
5289                 if (kthread_should_stop()) {
5290                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5291                         goto skip;
5292                 }
5293                 ITERATE_MDDEV(mddev2,tmp) {
5294                         if (mddev2 == mddev)
5295                                 continue;
5296                         if (mddev2->curr_resync && 
5297                             match_mddev_units(mddev,mddev2)) {
5298                                 DEFINE_WAIT(wq);
5299                                 if (mddev < mddev2 && mddev->curr_resync == 2) {
5300                                         /* arbitrarily yield */
5301                                         mddev->curr_resync = 1;
5302                                         wake_up(&resync_wait);
5303                                 }
5304                                 if (mddev > mddev2 && mddev->curr_resync == 1)
5305                                         /* no need to wait here, we can wait the next
5306                                          * time 'round when curr_resync == 2
5307                                          */
5308                                         continue;
5309                                 prepare_to_wait(&resync_wait, &wq, TASK_UNINTERRUPTIBLE);
5310                                 if (!kthread_should_stop() &&
5311                                     mddev2->curr_resync >= mddev->curr_resync) {
5312                                         printk(KERN_INFO "md: delaying %s of %s"
5313                                                " until %s has finished (they"
5314                                                " share one or more physical units)\n",
5315                                                desc, mdname(mddev), mdname(mddev2));
5316                                         mddev_put(mddev2);
5317                                         schedule();
5318                                         finish_wait(&resync_wait, &wq);
5319                                         goto try_again;
5320                                 }
5321                                 finish_wait(&resync_wait, &wq);
5322                         }
5323                 }
5324         } while (mddev->curr_resync < 2);
5325
5326         j = 0;
5327         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5328                 /* resync follows the size requested by the personality,
5329                  * which defaults to physical size, but can be virtual size
5330                  */
5331                 max_sectors = mddev->resync_max_sectors;
5332                 mddev->resync_mismatches = 0;
5333                 /* we don't use the checkpoint if there's a bitmap */
5334                 if (!mddev->bitmap &&
5335                     !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
5336                         j = mddev->recovery_cp;
5337         } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5338                 max_sectors = mddev->size << 1;
5339         else {
5340                 /* recovery follows the physical size of devices */
5341                 max_sectors = mddev->size << 1;
5342                 j = MaxSector;
5343                 ITERATE_RDEV(mddev,rdev,rtmp)
5344                         if (rdev->raid_disk >= 0 &&
5345                             !test_bit(Faulty, &rdev->flags) &&
5346                             !test_bit(In_sync, &rdev->flags) &&
5347                             rdev->recovery_offset < j)
5348                                 j = rdev->recovery_offset;
5349         }
5350
5351         printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
5352         printk(KERN_INFO "md: minimum _guaranteed_  speed:"
5353                 " %d KB/sec/disk.\n", speed_min(mddev));
5354         printk(KERN_INFO "md: using maximum available idle IO bandwidth "
5355                "(but not more than %d KB/sec) for %s.\n",
5356                speed_max(mddev), desc);
5357
5358         is_mddev_idle(mddev); /* this also initializes IO event counters */
5359
5360         io_sectors = 0;
5361         for (m = 0; m < SYNC_MARKS; m++) {
5362                 mark[m] = jiffies;
5363                 mark_cnt[m] = io_sectors;
5364         }
5365         last_mark = 0;
5366         mddev->resync_mark = mark[last_mark];
5367         mddev->resync_mark_cnt = mark_cnt[last_mark];
5368
5369         /*
5370          * Tune reconstruction:
5371          */
5372         window = 32*(PAGE_SIZE/512);
5373         printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
5374                 window/2,(unsigned long long) max_sectors/2);
5375
5376         atomic_set(&mddev->recovery_active, 0);
5377         init_waitqueue_head(&mddev->recovery_wait);
5378         last_check = 0;
5379
5380         if (j>2) {
5381                 printk(KERN_INFO 
5382                        "md: resuming %s of %s from checkpoint.\n",
5383                        desc, mdname(mddev));
5384                 mddev->curr_resync = j;
5385         }
5386
5387         while (j < max_sectors) {
5388                 sector_t sectors;
5389
5390                 skipped = 0;
5391                 sectors = mddev->pers->sync_request(mddev, j, &skipped,
5392                                             currspeed < speed_min(mddev));
5393                 if (sectors == 0) {
5394                         set_bit(MD_RECOVERY_ERR, &mddev->recovery);
5395                         goto out;
5396                 }
5397
5398                 if (!skipped) { /* actual IO requested */
5399                         io_sectors += sectors;
5400                         atomic_add(sectors, &mddev->recovery_active);
5401                 }
5402
5403                 j += sectors;
5404                 if (j>1) mddev->curr_resync = j;
5405                 mddev->curr_mark_cnt = io_sectors;
5406                 if (last_check == 0)
5407                         /* this is the earliers that rebuilt will be
5408                          * visible in /proc/mdstat
5409                          */
5410                         md_new_event(mddev);
5411
5412                 if (last_check + window > io_sectors || j == max_sectors)
5413                         continue;
5414
5415                 last_check = io_sectors;
5416
5417                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
5418                     test_bit(MD_RECOVERY_ERR, &mddev->recovery))
5419                         break;
5420
5421         repeat:
5422                 if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
5423                         /* step marks */
5424                         int next = (last_mark+1) % SYNC_MARKS;
5425
5426                         mddev->resync_mark = mark[next];
5427                         mddev->resync_mark_cnt = mark_cnt[next];
5428                         mark[next] = jiffies;
5429                         mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
5430                         last_mark = next;
5431                 }
5432
5433
5434                 if (kthread_should_stop()) {
5435                         /*
5436                          * got a signal, exit.
5437                          */
5438                         printk(KERN_INFO 
5439                                 "md: md_do_sync() got signal ... exiting\n");
5440                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5441                         goto out;
5442                 }
5443
5444                 /*
5445                  * this loop exits only if either when we are slower than
5446                  * the 'hard' speed limit, or the system was IO-idle for
5447                  * a jiffy.
5448                  * the system might be non-idle CPU-wise, but we only care
5449                  * about not overloading the IO subsystem. (things like an
5450                  * e2fsck being done on the RAID array should execute fast)
5451                  */
5452                 mddev->queue->unplug_fn(mddev->queue);
5453                 cond_resched();
5454
5455                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
5456                         /((jiffies-mddev->resync_mark)/HZ +1) +1;
5457
5458                 if (currspeed > speed_min(mddev)) {
5459                         if ((currspeed > speed_max(mddev)) ||
5460                                         !is_mddev_idle(mddev)) {
5461                                 msleep(500);
5462                                 goto repeat;
5463                         }
5464                 }
5465         }
5466         printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
5467         /*
5468          * this also signals 'finished resyncing' to md_stop
5469          */
5470  out:
5471         mddev->queue->unplug_fn(mddev->queue);
5472
5473         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
5474
5475         /* tell personality that we are finished */
5476         mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
5477
5478         if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
5479             !test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
5480             mddev->curr_resync > 2) {
5481                 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5482                         if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5483                                 if (mddev->curr_resync >= mddev->recovery_cp) {
5484                                         printk(KERN_INFO
5485                                                "md: checkpointing %s of %s.\n",
5486                                                desc, mdname(mddev));
5487                                         mddev->recovery_cp = mddev->curr_resync;
5488                                 }
5489                         } else
5490                                 mddev->recovery_cp = MaxSector;
5491                 } else {
5492                         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5493                                 mddev->curr_resync = MaxSector;
5494                         ITERATE_RDEV(mddev,rdev,rtmp)
5495                                 if (rdev->raid_disk >= 0 &&
5496                                     !test_bit(Faulty, &rdev->flags) &&
5497                                     !test_bit(In_sync, &rdev->flags) &&
5498                                     rdev->recovery_offset < mddev->curr_resync)
5499                                         rdev->recovery_offset = mddev->curr_resync;
5500                 }
5501         }
5502         set_bit(MD_CHANGE_DEVS, &mddev->flags);
5503
5504  skip:
5505         mddev->curr_resync = 0;
5506         wake_up(&resync_wait);
5507         set_bit(MD_RECOVERY_DONE, &mddev->recovery);
5508         md_wakeup_thread(mddev->thread);
5509 }
5510 EXPORT_SYMBOL_GPL(md_do_sync);
5511
5512
5513 static int remove_and_add_spares(mddev_t *mddev)
5514 {
5515         mdk_rdev_t *rdev;
5516         struct list_head *rtmp;
5517         int spares = 0;
5518
5519         ITERATE_RDEV(mddev,rdev,rtmp)
5520                 if (rdev->raid_disk >= 0 &&
5521                     (test_bit(Faulty, &rdev->flags) ||
5522                      ! test_bit(In_sync, &rdev->flags)) &&
5523                     atomic_read(&rdev->nr_pending)==0) {
5524                         if (mddev->pers->hot_remove_disk(
5525                                     mddev, rdev->raid_disk)==0) {
5526                                 char nm[20];
5527                                 sprintf(nm,"rd%d", rdev->raid_disk);
5528                                 sysfs_remove_link(&mddev->kobj, nm);
5529                                 rdev->raid_disk = -1;
5530                         }
5531                 }
5532
5533         if (mddev->degraded) {
5534                 ITERATE_RDEV(mddev,rdev,rtmp)
5535                         if (rdev->raid_disk < 0
5536                             && !test_bit(Faulty, &rdev->flags)) {
5537                                 rdev->recovery_offset = 0;
5538                                 if (mddev->pers->hot_add_disk(mddev,rdev)) {
5539                                         char nm[20];
5540                                         sprintf(nm, "rd%d", rdev->raid_disk);
5541                                         if (sysfs_create_link(&mddev->kobj,
5542                                                               &rdev->kobj, nm))
5543                                                 printk(KERN_WARNING
5544                                                        "md: cannot register "
5545                                                        "%s for %s\n",
5546                                                        nm, mdname(mddev));
5547                                         spares++;
5548                                         md_new_event(mddev);
5549                                 } else
5550                                         break;
5551                         }
5552         }
5553         return spares;
5554 }
5555 /*
5556  * This routine is regularly called by all per-raid-array threads to
5557  * deal with generic issues like resync and super-block update.
5558  * Raid personalities that don't have a thread (linear/raid0) do not
5559  * need this as they never do any recovery or update the superblock.
5560  *
5561  * It does not do any resync itself, but rather "forks" off other threads
5562  * to do that as needed.
5563  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
5564  * "->recovery" and create a thread at ->sync_thread.
5565  * When the thread finishes it sets MD_RECOVERY_DONE (and might set MD_RECOVERY_ERR)
5566  * and wakeups up this thread which will reap the thread and finish up.
5567  * This thread also removes any faulty devices (with nr_pending == 0).
5568  *
5569  * The overall approach is:
5570  *  1/ if the superblock needs updating, update it.
5571  *  2/ If a recovery thread is running, don't do anything else.
5572  *  3/ If recovery has finished, clean up, possibly marking spares active.
5573  *  4/ If there are any faulty devices, remove them.
5574  *  5/ If array is degraded, try to add spares devices
5575  *  6/ If array has spares or is not in-sync, start a resync thread.
5576  */
5577 void md_check_recovery(mddev_t *mddev)
5578 {
5579         mdk_rdev_t *rdev;
5580         struct list_head *rtmp;
5581
5582
5583         if (mddev->bitmap)
5584                 bitmap_daemon_work(mddev->bitmap);
5585
5586         if (mddev->ro)
5587                 return;
5588
5589         if (signal_pending(current)) {
5590                 if (mddev->pers->sync_request) {
5591                         printk(KERN_INFO "md: %s in immediate safe mode\n",
5592                                mdname(mddev));
5593                         mddev->safemode = 2;
5594                 }
5595                 flush_signals(current);
5596         }
5597
5598         if ( ! (
5599                 mddev->flags ||
5600                 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
5601                 test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
5602                 (mddev->safemode == 1) ||
5603                 (mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
5604                  && !mddev->in_sync && mddev->recovery_cp == MaxSector)
5605                 ))
5606                 return;
5607
5608         if (mddev_trylock(mddev)) {
5609                 int spares = 0;
5610
5611                 spin_lock_irq(&mddev->write_lock);
5612                 if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
5613                     !mddev->in_sync && mddev->recovery_cp == MaxSector) {
5614                         mddev->in_sync = 1;
5615                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
5616                 }
5617                 if (mddev->safemode == 1)
5618                         mddev->safemode = 0;
5619                 spin_unlock_irq(&mddev->write_lock);
5620
5621                 if (mddev->flags)
5622                         md_update_sb(mddev, 0);
5623
5624
5625                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
5626                     !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
5627                         /* resync/recovery still happening */
5628                         clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5629                         goto unlock;
5630                 }
5631                 if (mddev->sync_thread) {
5632                         /* resync has finished, collect result */
5633                         md_unregister_thread(mddev->sync_thread);
5634                         mddev->sync_thread = NULL;
5635                         if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
5636                             !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5637                                 /* success...*/
5638                                 /* activate any spares */
5639                                 mddev->pers->spare_active(mddev);
5640                         }
5641                         md_update_sb(mddev, 1);
5642
5643                         /* if array is no-longer degraded, then any saved_raid_disk
5644                          * information must be scrapped
5645                          */
5646                         if (!mddev->degraded)
5647                                 ITERATE_RDEV(mddev,rdev,rtmp)
5648                                         rdev->saved_raid_disk = -1;
5649
5650                         mddev->recovery = 0;
5651                         /* flag recovery needed just to double check */
5652                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5653                         md_new_event(mddev);
5654                         goto unlock;
5655                 }
5656                 /* Clear some bits that don't mean anything, but
5657                  * might be left set
5658                  */
5659                 clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5660                 clear_bit(MD_RECOVERY_ERR, &mddev->recovery);
5661                 clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
5662                 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
5663
5664                 if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
5665                         goto unlock;
5666                 /* no recovery is running.
5667                  * remove any failed drives, then
5668                  * add spares if possible.
5669                  * Spare are also removed and re-added, to allow
5670                  * the personality to fail the re-add.
5671                  */
5672
5673                 if (mddev->reshape_position != MaxSector) {
5674                         if (mddev->pers->check_reshape(mddev) != 0)
5675                                 /* Cannot proceed */
5676                                 goto unlock;
5677                         set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5678                 } else if ((spares = remove_and_add_spares(mddev))) {
5679                         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5680                         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5681                 } else if (mddev->recovery_cp < MaxSector) {
5682                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5683                 } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
5684                         /* nothing to be done ... */
5685                         goto unlock;
5686
5687                 if (mddev->pers->sync_request) {
5688                         set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5689                         if (spares && mddev->bitmap && ! mddev->bitmap->file) {
5690                                 /* We are adding a device or devices to an array
5691                                  * which has the bitmap stored on all devices.
5692                                  * So make sure all bitmap pages get written
5693                                  */
5694                                 bitmap_write_all(mddev->bitmap);
5695                         }
5696                         mddev->sync_thread = md_register_thread(md_do_sync,
5697                                                                 mddev,
5698                                                                 "%s_resync");
5699                         if (!mddev->sync_thread) {
5700                                 printk(KERN_ERR "%s: could not start resync"
5701                                         " thread...\n", 
5702                                         mdname(mddev));
5703                                 /* leave the spares where they are, it shouldn't hurt */
5704                                 mddev->recovery = 0;
5705                         } else
5706                                 md_wakeup_thread(mddev->sync_thread);
5707                         md_new_event(mddev);
5708                 }
5709         unlock:
5710                 mddev_unlock(mddev);
5711         }
5712 }
5713
5714 static int md_notify_reboot(struct notifier_block *this,
5715                             unsigned long code, void *x)
5716 {
5717         struct list_head *tmp;
5718         mddev_t *mddev;
5719
5720         if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
5721
5722                 printk(KERN_INFO "md: stopping all md devices.\n");
5723
5724                 ITERATE_MDDEV(mddev,tmp)
5725                         if (mddev_trylock(mddev)) {
5726                                 do_md_stop (mddev, 1);
5727                                 mddev_unlock(mddev);
5728                         }
5729                 /*
5730                  * certain more exotic SCSI devices are known to be
5731                  * volatile wrt too early system reboots. While the
5732                  * right place to handle this issue is the given
5733                  * driver, we do want to have a safe RAID driver ...
5734                  */
5735                 mdelay(1000*1);
5736         }
5737         return NOTIFY_DONE;
5738 }
5739
5740 static struct notifier_block md_notifier = {
5741         .notifier_call  = md_notify_reboot,
5742         .next           = NULL,
5743         .priority       = INT_MAX, /* before any real devices */
5744 };
5745
5746 static void md_geninit(void)
5747 {
5748         struct proc_dir_entry *p;
5749
5750         dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
5751
5752         p = create_proc_entry("mdstat", S_IRUGO, NULL);
5753         if (p)
5754                 p->proc_fops = &md_seq_fops;
5755 }
5756
5757 static int __init md_init(void)
5758 {
5759         if (register_blkdev(MAJOR_NR, "md"))
5760                 return -1;
5761         if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
5762                 unregister_blkdev(MAJOR_NR, "md");
5763                 return -1;
5764         }
5765         blk_register_region(MKDEV(MAJOR_NR, 0), 1UL<<MINORBITS, THIS_MODULE,
5766                             md_probe, NULL, NULL);
5767         blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
5768                             md_probe, NULL, NULL);
5769
5770         register_reboot_notifier(&md_notifier);
5771         raid_table_header = register_sysctl_table(raid_root_table);
5772
5773         md_geninit();
5774         return (0);
5775 }
5776
5777
5778 #ifndef MODULE
5779
5780 /*
5781  * Searches all registered partitions for autorun RAID arrays
5782  * at boot time.
5783  */
5784 static dev_t detected_devices[128];
5785 static int dev_cnt;
5786
5787 void md_autodetect_dev(dev_t dev)
5788 {
5789         if (dev_cnt >= 0 && dev_cnt < 127)
5790                 detected_devices[dev_cnt++] = dev;
5791 }
5792
5793
5794 static void autostart_arrays(int part)
5795 {
5796         mdk_rdev_t *rdev;
5797         int i;
5798
5799         printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
5800
5801         for (i = 0; i < dev_cnt; i++) {
5802                 dev_t dev = detected_devices[i];
5803
5804                 rdev = md_import_device(dev,0, 90);
5805                 if (IS_ERR(rdev))
5806                         continue;
5807
5808                 if (test_bit(Faulty, &rdev->flags)) {
5809                         MD_BUG();
5810                         continue;
5811                 }
5812                 list_add(&rdev->same_set, &pending_raid_disks);
5813         }
5814         dev_cnt = 0;
5815
5816         autorun_devices(part);
5817 }
5818
5819 #endif /* !MODULE */
5820
5821 static __exit void md_exit(void)
5822 {
5823         mddev_t *mddev;
5824         struct list_head *tmp;
5825
5826         blk_unregister_region(MKDEV(MAJOR_NR,0), 1U << MINORBITS);
5827         blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
5828
5829         unregister_blkdev(MAJOR_NR,"md");
5830         unregister_blkdev(mdp_major, "mdp");
5831         unregister_reboot_notifier(&md_notifier);
5832         unregister_sysctl_table(raid_table_header);
5833         remove_proc_entry("mdstat", NULL);
5834         ITERATE_MDDEV(mddev,tmp) {
5835                 struct gendisk *disk = mddev->gendisk;
5836                 if (!disk)
5837                         continue;
5838                 export_array(mddev);
5839                 del_gendisk(disk);
5840                 put_disk(disk);
5841                 mddev->gendisk = NULL;
5842                 mddev_put(mddev);
5843         }
5844 }
5845
5846 subsys_initcall(md_init);
5847 module_exit(md_exit)
5848
5849 static int get_ro(char *buffer, struct kernel_param *kp)
5850 {
5851         return sprintf(buffer, "%d", start_readonly);
5852 }
5853 static int set_ro(const char *val, struct kernel_param *kp)
5854 {
5855         char *e;
5856         int num = simple_strtoul(val, &e, 10);
5857         if (*val && (*e == '\0' || *e == '\n')) {
5858                 start_readonly = num;
5859                 return 0;
5860         }
5861         return -EINVAL;
5862 }
5863
5864 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
5865 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
5866
5867
5868 EXPORT_SYMBOL(register_md_personality);
5869 EXPORT_SYMBOL(unregister_md_personality);
5870 EXPORT_SYMBOL(md_error);
5871 EXPORT_SYMBOL(md_done_sync);
5872 EXPORT_SYMBOL(md_write_start);
5873 EXPORT_SYMBOL(md_write_end);
5874 EXPORT_SYMBOL(md_register_thread);
5875 EXPORT_SYMBOL(md_unregister_thread);
5876 EXPORT_SYMBOL(md_wakeup_thread);
5877 EXPORT_SYMBOL(md_check_recovery);
5878 MODULE_LICENSE("GPL");
5879 MODULE_ALIAS("md");
5880 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);