xref: /linux/drivers/md/md.c (revision 71901cc4109b3794b863884e348aff3c71e693cc)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/blkdev.h>
37 #include <linux/sysctl.h>
38 #include <linux/seq_file.h>
39 #include <linux/smp_lock.h>
40 #include <linux/buffer_head.h> /* for invalidate_bdev */
41 #include <linux/poll.h>
42 #include <linux/ctype.h>
43 #include <linux/string.h>
44 #include <linux/hdreg.h>
45 #include <linux/proc_fs.h>
46 #include <linux/random.h>
47 #include <linux/reboot.h>
48 #include <linux/file.h>
49 #include <linux/compat.h>
50 #include <linux/delay.h>
51 #include <linux/raid/md_p.h>
52 #include <linux/raid/md_u.h>
53 #include <linux/slab.h>
54 #include "md.h"
55 #include "bitmap.h"
56 
57 #define DEBUG 0
58 #define dprintk(x...) ((void)(DEBUG && printk(x)))
59 
60 
61 #ifndef MODULE
62 static void autostart_arrays(int part);
63 #endif
64 
65 static LIST_HEAD(pers_list);
66 static DEFINE_SPINLOCK(pers_lock);
67 
68 static void md_print_devices(void);
69 
70 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
71 
72 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
73 
74 /*
75  * Default number of read corrections we'll attempt on an rdev
76  * before ejecting it from the array. We divide the read error
77  * count by 2 for every hour elapsed between read errors.
78  */
79 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
80 /*
81  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
82  * is 1000 KB/sec, so the extra system load does not show up that much.
83  * Increase it if you want to have more _guaranteed_ speed. Note that
84  * the RAID driver will use the maximum available bandwidth if the IO
85  * subsystem is idle. There is also an 'absolute maximum' reconstruction
86  * speed limit - in case reconstruction slows down your system despite
87  * idle IO detection.
88  *
89  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
90  * or /sys/block/mdX/md/sync_speed_{min,max}
91  */
92 
93 static int sysctl_speed_limit_min = 1000;
94 static int sysctl_speed_limit_max = 200000;
95 static inline int speed_min(mddev_t *mddev)
96 {
97 	return mddev->sync_speed_min ?
98 		mddev->sync_speed_min : sysctl_speed_limit_min;
99 }
100 
101 static inline int speed_max(mddev_t *mddev)
102 {
103 	return mddev->sync_speed_max ?
104 		mddev->sync_speed_max : sysctl_speed_limit_max;
105 }
106 
107 static struct ctl_table_header *raid_table_header;
108 
109 static ctl_table raid_table[] = {
110 	{
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 		.procname	= "speed_limit_max",
119 		.data		= &sysctl_speed_limit_max,
120 		.maxlen		= sizeof(int),
121 		.mode		= S_IRUGO|S_IWUSR,
122 		.proc_handler	= proc_dointvec,
123 	},
124 	{ }
125 };
126 
127 static ctl_table raid_dir_table[] = {
128 	{
129 		.procname	= "raid",
130 		.maxlen		= 0,
131 		.mode		= S_IRUGO|S_IXUGO,
132 		.child		= raid_table,
133 	},
134 	{ }
135 };
136 
137 static ctl_table raid_root_table[] = {
138 	{
139 		.procname	= "dev",
140 		.maxlen		= 0,
141 		.mode		= 0555,
142 		.child		= raid_dir_table,
143 	},
144 	{  }
145 };
146 
147 static const struct block_device_operations md_fops;
148 
149 static int start_readonly;
150 
151 /*
152  * We have a system wide 'event count' that is incremented
153  * on any 'interesting' event, and readers of /proc/mdstat
154  * can use 'poll' or 'select' to find out when the event
155  * count increases.
156  *
157  * Events are:
158  *  start array, stop array, error, add device, remove device,
159  *  start build, activate spare
160  */
161 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
162 static atomic_t md_event_count;
163 void md_new_event(mddev_t *mddev)
164 {
165 	atomic_inc(&md_event_count);
166 	wake_up(&md_event_waiters);
167 }
168 EXPORT_SYMBOL_GPL(md_new_event);
169 
170 /* Alternate version that can be called from interrupts
171  * when calling sysfs_notify isn't needed.
172  */
173 static void md_new_event_inintr(mddev_t *mddev)
174 {
175 	atomic_inc(&md_event_count);
176 	wake_up(&md_event_waiters);
177 }
178 
179 /*
180  * Enables to iterate over all existing md arrays
181  * all_mddevs_lock protects this list.
182  */
183 static LIST_HEAD(all_mddevs);
184 static DEFINE_SPINLOCK(all_mddevs_lock);
185 
186 
187 /*
188  * iterates through all used mddevs in the system.
189  * We take care to grab the all_mddevs_lock whenever navigating
190  * the list, and to always hold a refcount when unlocked.
191  * Any code which breaks out of this loop while own
192  * a reference to the current mddev and must mddev_put it.
193  */
194 #define for_each_mddev(mddev,tmp)					\
195 									\
196 	for (({ spin_lock(&all_mddevs_lock); 				\
197 		tmp = all_mddevs.next;					\
198 		mddev = NULL;});					\
199 	     ({ if (tmp != &all_mddevs)					\
200 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
201 		spin_unlock(&all_mddevs_lock);				\
202 		if (mddev) mddev_put(mddev);				\
203 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
204 		tmp != &all_mddevs;});					\
205 	     ({ spin_lock(&all_mddevs_lock);				\
206 		tmp = tmp->next;})					\
207 		)
208 
209 
210 /* Rather than calling directly into the personality make_request function,
211  * IO requests come here first so that we can check if the device is
212  * being suspended pending a reconfiguration.
213  * We hold a refcount over the call to ->make_request.  By the time that
214  * call has finished, the bio has been linked into some internal structure
215  * and so is visible to ->quiesce(), so we don't need the refcount any more.
216  */
217 static int md_make_request(struct request_queue *q, struct bio *bio)
218 {
219 	const int rw = bio_data_dir(bio);
220 	mddev_t *mddev = q->queuedata;
221 	int rv;
222 	int cpu;
223 
224 	if (mddev == NULL || mddev->pers == NULL) {
225 		bio_io_error(bio);
226 		return 0;
227 	}
228 	rcu_read_lock();
229 	if (mddev->suspended || mddev->barrier) {
230 		DEFINE_WAIT(__wait);
231 		for (;;) {
232 			prepare_to_wait(&mddev->sb_wait, &__wait,
233 					TASK_UNINTERRUPTIBLE);
234 			if (!mddev->suspended && !mddev->barrier)
235 				break;
236 			rcu_read_unlock();
237 			schedule();
238 			rcu_read_lock();
239 		}
240 		finish_wait(&mddev->sb_wait, &__wait);
241 	}
242 	atomic_inc(&mddev->active_io);
243 	rcu_read_unlock();
244 
245 	rv = mddev->pers->make_request(mddev, bio);
246 
247 	cpu = part_stat_lock();
248 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
249 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
250 		      bio_sectors(bio));
251 	part_stat_unlock();
252 
253 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
254 		wake_up(&mddev->sb_wait);
255 
256 	return rv;
257 }
258 
259 /* mddev_suspend makes sure no new requests are submitted
260  * to the device, and that any requests that have been submitted
261  * are completely handled.
262  * Once ->stop is called and completes, the module will be completely
263  * unused.
264  */
265 void mddev_suspend(mddev_t *mddev)
266 {
267 	BUG_ON(mddev->suspended);
268 	mddev->suspended = 1;
269 	synchronize_rcu();
270 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
271 	mddev->pers->quiesce(mddev, 1);
272 }
273 EXPORT_SYMBOL_GPL(mddev_suspend);
274 
275 void mddev_resume(mddev_t *mddev)
276 {
277 	mddev->suspended = 0;
278 	wake_up(&mddev->sb_wait);
279 	mddev->pers->quiesce(mddev, 0);
280 }
281 EXPORT_SYMBOL_GPL(mddev_resume);
282 
283 int mddev_congested(mddev_t *mddev, int bits)
284 {
285 	if (mddev->barrier)
286 		return 1;
287 	return mddev->suspended;
288 }
289 EXPORT_SYMBOL(mddev_congested);
290 
291 /*
292  * Generic barrier handling for md
293  */
294 
295 #define POST_REQUEST_BARRIER ((void*)1)
296 
297 static void md_end_barrier(struct bio *bio, int err)
298 {
299 	mdk_rdev_t *rdev = bio->bi_private;
300 	mddev_t *mddev = rdev->mddev;
301 	if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
302 		set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
303 
304 	rdev_dec_pending(rdev, mddev);
305 
306 	if (atomic_dec_and_test(&mddev->flush_pending)) {
307 		if (mddev->barrier == POST_REQUEST_BARRIER) {
308 			/* This was a post-request barrier */
309 			mddev->barrier = NULL;
310 			wake_up(&mddev->sb_wait);
311 		} else
312 			/* The pre-request barrier has finished */
313 			schedule_work(&mddev->barrier_work);
314 	}
315 	bio_put(bio);
316 }
317 
318 static void submit_barriers(mddev_t *mddev)
319 {
320 	mdk_rdev_t *rdev;
321 
322 	rcu_read_lock();
323 	list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
324 		if (rdev->raid_disk >= 0 &&
325 		    !test_bit(Faulty, &rdev->flags)) {
326 			/* Take two references, one is dropped
327 			 * when request finishes, one after
328 			 * we reclaim rcu_read_lock
329 			 */
330 			struct bio *bi;
331 			atomic_inc(&rdev->nr_pending);
332 			atomic_inc(&rdev->nr_pending);
333 			rcu_read_unlock();
334 			bi = bio_alloc(GFP_KERNEL, 0);
335 			bi->bi_end_io = md_end_barrier;
336 			bi->bi_private = rdev;
337 			bi->bi_bdev = rdev->bdev;
338 			atomic_inc(&mddev->flush_pending);
339 			submit_bio(WRITE_BARRIER, bi);
340 			rcu_read_lock();
341 			rdev_dec_pending(rdev, mddev);
342 		}
343 	rcu_read_unlock();
344 }
345 
346 static void md_submit_barrier(struct work_struct *ws)
347 {
348 	mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
349 	struct bio *bio = mddev->barrier;
350 
351 	atomic_set(&mddev->flush_pending, 1);
352 
353 	if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
354 		bio_endio(bio, -EOPNOTSUPP);
355 	else if (bio->bi_size == 0)
356 		/* an empty barrier - all done */
357 		bio_endio(bio, 0);
358 	else {
359 		bio->bi_rw &= ~REQ_HARDBARRIER;
360 		if (mddev->pers->make_request(mddev, bio))
361 			generic_make_request(bio);
362 		mddev->barrier = POST_REQUEST_BARRIER;
363 		submit_barriers(mddev);
364 	}
365 	if (atomic_dec_and_test(&mddev->flush_pending)) {
366 		mddev->barrier = NULL;
367 		wake_up(&mddev->sb_wait);
368 	}
369 }
370 
371 void md_barrier_request(mddev_t *mddev, struct bio *bio)
372 {
373 	spin_lock_irq(&mddev->write_lock);
374 	wait_event_lock_irq(mddev->sb_wait,
375 			    !mddev->barrier,
376 			    mddev->write_lock, /*nothing*/);
377 	mddev->barrier = bio;
378 	spin_unlock_irq(&mddev->write_lock);
379 
380 	atomic_set(&mddev->flush_pending, 1);
381 	INIT_WORK(&mddev->barrier_work, md_submit_barrier);
382 
383 	submit_barriers(mddev);
384 
385 	if (atomic_dec_and_test(&mddev->flush_pending))
386 		schedule_work(&mddev->barrier_work);
387 }
388 EXPORT_SYMBOL(md_barrier_request);
389 
390 /* Support for plugging.
391  * This mirrors the plugging support in request_queue, but does not
392  * require having a whole queue
393  */
394 static void plugger_work(struct work_struct *work)
395 {
396 	struct plug_handle *plug =
397 		container_of(work, struct plug_handle, unplug_work);
398 	plug->unplug_fn(plug);
399 }
400 static void plugger_timeout(unsigned long data)
401 {
402 	struct plug_handle *plug = (void *)data;
403 	kblockd_schedule_work(NULL, &plug->unplug_work);
404 }
405 void plugger_init(struct plug_handle *plug,
406 		  void (*unplug_fn)(struct plug_handle *))
407 {
408 	plug->unplug_flag = 0;
409 	plug->unplug_fn = unplug_fn;
410 	init_timer(&plug->unplug_timer);
411 	plug->unplug_timer.function = plugger_timeout;
412 	plug->unplug_timer.data = (unsigned long)plug;
413 	INIT_WORK(&plug->unplug_work, plugger_work);
414 }
415 EXPORT_SYMBOL_GPL(plugger_init);
416 
417 void plugger_set_plug(struct plug_handle *plug)
418 {
419 	if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag))
420 		mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1);
421 }
422 EXPORT_SYMBOL_GPL(plugger_set_plug);
423 
424 int plugger_remove_plug(struct plug_handle *plug)
425 {
426 	if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) {
427 		del_timer(&plug->unplug_timer);
428 		return 1;
429 	} else
430 		return 0;
431 }
432 EXPORT_SYMBOL_GPL(plugger_remove_plug);
433 
434 
435 static inline mddev_t *mddev_get(mddev_t *mddev)
436 {
437 	atomic_inc(&mddev->active);
438 	return mddev;
439 }
440 
441 static void mddev_delayed_delete(struct work_struct *ws);
442 
443 static void mddev_put(mddev_t *mddev)
444 {
445 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
446 		return;
447 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
448 	    mddev->ctime == 0 && !mddev->hold_active) {
449 		/* Array is not configured at all, and not held active,
450 		 * so destroy it */
451 		list_del(&mddev->all_mddevs);
452 		if (mddev->gendisk) {
453 			/* we did a probe so need to clean up.
454 			 * Call schedule_work inside the spinlock
455 			 * so that flush_scheduled_work() after
456 			 * mddev_find will succeed in waiting for the
457 			 * work to be done.
458 			 */
459 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
460 			schedule_work(&mddev->del_work);
461 		} else
462 			kfree(mddev);
463 	}
464 	spin_unlock(&all_mddevs_lock);
465 }
466 
467 void mddev_init(mddev_t *mddev)
468 {
469 	mutex_init(&mddev->open_mutex);
470 	mutex_init(&mddev->reconfig_mutex);
471 	mutex_init(&mddev->bitmap_info.mutex);
472 	INIT_LIST_HEAD(&mddev->disks);
473 	INIT_LIST_HEAD(&mddev->all_mddevs);
474 	init_timer(&mddev->safemode_timer);
475 	atomic_set(&mddev->active, 1);
476 	atomic_set(&mddev->openers, 0);
477 	atomic_set(&mddev->active_io, 0);
478 	spin_lock_init(&mddev->write_lock);
479 	atomic_set(&mddev->flush_pending, 0);
480 	init_waitqueue_head(&mddev->sb_wait);
481 	init_waitqueue_head(&mddev->recovery_wait);
482 	mddev->reshape_position = MaxSector;
483 	mddev->resync_min = 0;
484 	mddev->resync_max = MaxSector;
485 	mddev->level = LEVEL_NONE;
486 }
487 EXPORT_SYMBOL_GPL(mddev_init);
488 
489 static mddev_t * mddev_find(dev_t unit)
490 {
491 	mddev_t *mddev, *new = NULL;
492 
493  retry:
494 	spin_lock(&all_mddevs_lock);
495 
496 	if (unit) {
497 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
498 			if (mddev->unit == unit) {
499 				mddev_get(mddev);
500 				spin_unlock(&all_mddevs_lock);
501 				kfree(new);
502 				return mddev;
503 			}
504 
505 		if (new) {
506 			list_add(&new->all_mddevs, &all_mddevs);
507 			spin_unlock(&all_mddevs_lock);
508 			new->hold_active = UNTIL_IOCTL;
509 			return new;
510 		}
511 	} else if (new) {
512 		/* find an unused unit number */
513 		static int next_minor = 512;
514 		int start = next_minor;
515 		int is_free = 0;
516 		int dev = 0;
517 		while (!is_free) {
518 			dev = MKDEV(MD_MAJOR, next_minor);
519 			next_minor++;
520 			if (next_minor > MINORMASK)
521 				next_minor = 0;
522 			if (next_minor == start) {
523 				/* Oh dear, all in use. */
524 				spin_unlock(&all_mddevs_lock);
525 				kfree(new);
526 				return NULL;
527 			}
528 
529 			is_free = 1;
530 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
531 				if (mddev->unit == dev) {
532 					is_free = 0;
533 					break;
534 				}
535 		}
536 		new->unit = dev;
537 		new->md_minor = MINOR(dev);
538 		new->hold_active = UNTIL_STOP;
539 		list_add(&new->all_mddevs, &all_mddevs);
540 		spin_unlock(&all_mddevs_lock);
541 		return new;
542 	}
543 	spin_unlock(&all_mddevs_lock);
544 
545 	new = kzalloc(sizeof(*new), GFP_KERNEL);
546 	if (!new)
547 		return NULL;
548 
549 	new->unit = unit;
550 	if (MAJOR(unit) == MD_MAJOR)
551 		new->md_minor = MINOR(unit);
552 	else
553 		new->md_minor = MINOR(unit) >> MdpMinorShift;
554 
555 	mddev_init(new);
556 
557 	goto retry;
558 }
559 
560 static inline int mddev_lock(mddev_t * mddev)
561 {
562 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
563 }
564 
565 static inline int mddev_is_locked(mddev_t *mddev)
566 {
567 	return mutex_is_locked(&mddev->reconfig_mutex);
568 }
569 
570 static inline int mddev_trylock(mddev_t * mddev)
571 {
572 	return mutex_trylock(&mddev->reconfig_mutex);
573 }
574 
575 static struct attribute_group md_redundancy_group;
576 
577 static void mddev_unlock(mddev_t * mddev)
578 {
579 	if (mddev->to_remove) {
580 		/* These cannot be removed under reconfig_mutex as
581 		 * an access to the files will try to take reconfig_mutex
582 		 * while holding the file unremovable, which leads to
583 		 * a deadlock.
584 		 * So hold set sysfs_active while the remove in happeing,
585 		 * and anything else which might set ->to_remove or my
586 		 * otherwise change the sysfs namespace will fail with
587 		 * -EBUSY if sysfs_active is still set.
588 		 * We set sysfs_active under reconfig_mutex and elsewhere
589 		 * test it under the same mutex to ensure its correct value
590 		 * is seen.
591 		 */
592 		struct attribute_group *to_remove = mddev->to_remove;
593 		mddev->to_remove = NULL;
594 		mddev->sysfs_active = 1;
595 		mutex_unlock(&mddev->reconfig_mutex);
596 
597 		if (mddev->kobj.sd) {
598 			if (to_remove != &md_redundancy_group)
599 				sysfs_remove_group(&mddev->kobj, to_remove);
600 			if (mddev->pers == NULL ||
601 			    mddev->pers->sync_request == NULL) {
602 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
603 				if (mddev->sysfs_action)
604 					sysfs_put(mddev->sysfs_action);
605 				mddev->sysfs_action = NULL;
606 			}
607 		}
608 		mddev->sysfs_active = 0;
609 	} else
610 		mutex_unlock(&mddev->reconfig_mutex);
611 
612 	md_wakeup_thread(mddev->thread);
613 }
614 
615 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
616 {
617 	mdk_rdev_t *rdev;
618 
619 	list_for_each_entry(rdev, &mddev->disks, same_set)
620 		if (rdev->desc_nr == nr)
621 			return rdev;
622 
623 	return NULL;
624 }
625 
626 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
627 {
628 	mdk_rdev_t *rdev;
629 
630 	list_for_each_entry(rdev, &mddev->disks, same_set)
631 		if (rdev->bdev->bd_dev == dev)
632 			return rdev;
633 
634 	return NULL;
635 }
636 
637 static struct mdk_personality *find_pers(int level, char *clevel)
638 {
639 	struct mdk_personality *pers;
640 	list_for_each_entry(pers, &pers_list, list) {
641 		if (level != LEVEL_NONE && pers->level == level)
642 			return pers;
643 		if (strcmp(pers->name, clevel)==0)
644 			return pers;
645 	}
646 	return NULL;
647 }
648 
649 /* return the offset of the super block in 512byte sectors */
650 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
651 {
652 	sector_t num_sectors = bdev->bd_inode->i_size / 512;
653 	return MD_NEW_SIZE_SECTORS(num_sectors);
654 }
655 
656 static int alloc_disk_sb(mdk_rdev_t * rdev)
657 {
658 	if (rdev->sb_page)
659 		MD_BUG();
660 
661 	rdev->sb_page = alloc_page(GFP_KERNEL);
662 	if (!rdev->sb_page) {
663 		printk(KERN_ALERT "md: out of memory.\n");
664 		return -ENOMEM;
665 	}
666 
667 	return 0;
668 }
669 
670 static void free_disk_sb(mdk_rdev_t * rdev)
671 {
672 	if (rdev->sb_page) {
673 		put_page(rdev->sb_page);
674 		rdev->sb_loaded = 0;
675 		rdev->sb_page = NULL;
676 		rdev->sb_start = 0;
677 		rdev->sectors = 0;
678 	}
679 }
680 
681 
682 static void super_written(struct bio *bio, int error)
683 {
684 	mdk_rdev_t *rdev = bio->bi_private;
685 	mddev_t *mddev = rdev->mddev;
686 
687 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
688 		printk("md: super_written gets error=%d, uptodate=%d\n",
689 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
690 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
691 		md_error(mddev, rdev);
692 	}
693 
694 	if (atomic_dec_and_test(&mddev->pending_writes))
695 		wake_up(&mddev->sb_wait);
696 	bio_put(bio);
697 }
698 
699 static void super_written_barrier(struct bio *bio, int error)
700 {
701 	struct bio *bio2 = bio->bi_private;
702 	mdk_rdev_t *rdev = bio2->bi_private;
703 	mddev_t *mddev = rdev->mddev;
704 
705 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
706 	    error == -EOPNOTSUPP) {
707 		unsigned long flags;
708 		/* barriers don't appear to be supported :-( */
709 		set_bit(BarriersNotsupp, &rdev->flags);
710 		mddev->barriers_work = 0;
711 		spin_lock_irqsave(&mddev->write_lock, flags);
712 		bio2->bi_next = mddev->biolist;
713 		mddev->biolist = bio2;
714 		spin_unlock_irqrestore(&mddev->write_lock, flags);
715 		wake_up(&mddev->sb_wait);
716 		bio_put(bio);
717 	} else {
718 		bio_put(bio2);
719 		bio->bi_private = rdev;
720 		super_written(bio, error);
721 	}
722 }
723 
724 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
725 		   sector_t sector, int size, struct page *page)
726 {
727 	/* write first size bytes of page to sector of rdev
728 	 * Increment mddev->pending_writes before returning
729 	 * and decrement it on completion, waking up sb_wait
730 	 * if zero is reached.
731 	 * If an error occurred, call md_error
732 	 *
733 	 * As we might need to resubmit the request if REQ_HARDBARRIER
734 	 * causes ENOTSUPP, we allocate a spare bio...
735 	 */
736 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
737 	int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG;
738 
739 	bio->bi_bdev = rdev->bdev;
740 	bio->bi_sector = sector;
741 	bio_add_page(bio, page, size, 0);
742 	bio->bi_private = rdev;
743 	bio->bi_end_io = super_written;
744 	bio->bi_rw = rw;
745 
746 	atomic_inc(&mddev->pending_writes);
747 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
748 		struct bio *rbio;
749 		rw |= REQ_HARDBARRIER;
750 		rbio = bio_clone(bio, GFP_NOIO);
751 		rbio->bi_private = bio;
752 		rbio->bi_end_io = super_written_barrier;
753 		submit_bio(rw, rbio);
754 	} else
755 		submit_bio(rw, bio);
756 }
757 
758 void md_super_wait(mddev_t *mddev)
759 {
760 	/* wait for all superblock writes that were scheduled to complete.
761 	 * if any had to be retried (due to BARRIER problems), retry them
762 	 */
763 	DEFINE_WAIT(wq);
764 	for(;;) {
765 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
766 		if (atomic_read(&mddev->pending_writes)==0)
767 			break;
768 		while (mddev->biolist) {
769 			struct bio *bio;
770 			spin_lock_irq(&mddev->write_lock);
771 			bio = mddev->biolist;
772 			mddev->biolist = bio->bi_next ;
773 			bio->bi_next = NULL;
774 			spin_unlock_irq(&mddev->write_lock);
775 			submit_bio(bio->bi_rw, bio);
776 		}
777 		schedule();
778 	}
779 	finish_wait(&mddev->sb_wait, &wq);
780 }
781 
782 static void bi_complete(struct bio *bio, int error)
783 {
784 	complete((struct completion*)bio->bi_private);
785 }
786 
787 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
788 		   struct page *page, int rw)
789 {
790 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
791 	struct completion event;
792 	int ret;
793 
794 	rw |= REQ_SYNC | REQ_UNPLUG;
795 
796 	bio->bi_bdev = bdev;
797 	bio->bi_sector = sector;
798 	bio_add_page(bio, page, size, 0);
799 	init_completion(&event);
800 	bio->bi_private = &event;
801 	bio->bi_end_io = bi_complete;
802 	submit_bio(rw, bio);
803 	wait_for_completion(&event);
804 
805 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
806 	bio_put(bio);
807 	return ret;
808 }
809 EXPORT_SYMBOL_GPL(sync_page_io);
810 
811 static int read_disk_sb(mdk_rdev_t * rdev, int size)
812 {
813 	char b[BDEVNAME_SIZE];
814 	if (!rdev->sb_page) {
815 		MD_BUG();
816 		return -EINVAL;
817 	}
818 	if (rdev->sb_loaded)
819 		return 0;
820 
821 
822 	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
823 		goto fail;
824 	rdev->sb_loaded = 1;
825 	return 0;
826 
827 fail:
828 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
829 		bdevname(rdev->bdev,b));
830 	return -EINVAL;
831 }
832 
833 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
834 {
835 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
836 		sb1->set_uuid1 == sb2->set_uuid1 &&
837 		sb1->set_uuid2 == sb2->set_uuid2 &&
838 		sb1->set_uuid3 == sb2->set_uuid3;
839 }
840 
841 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
842 {
843 	int ret;
844 	mdp_super_t *tmp1, *tmp2;
845 
846 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
847 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
848 
849 	if (!tmp1 || !tmp2) {
850 		ret = 0;
851 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
852 		goto abort;
853 	}
854 
855 	*tmp1 = *sb1;
856 	*tmp2 = *sb2;
857 
858 	/*
859 	 * nr_disks is not constant
860 	 */
861 	tmp1->nr_disks = 0;
862 	tmp2->nr_disks = 0;
863 
864 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
865 abort:
866 	kfree(tmp1);
867 	kfree(tmp2);
868 	return ret;
869 }
870 
871 
872 static u32 md_csum_fold(u32 csum)
873 {
874 	csum = (csum & 0xffff) + (csum >> 16);
875 	return (csum & 0xffff) + (csum >> 16);
876 }
877 
878 static unsigned int calc_sb_csum(mdp_super_t * sb)
879 {
880 	u64 newcsum = 0;
881 	u32 *sb32 = (u32*)sb;
882 	int i;
883 	unsigned int disk_csum, csum;
884 
885 	disk_csum = sb->sb_csum;
886 	sb->sb_csum = 0;
887 
888 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
889 		newcsum += sb32[i];
890 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
891 
892 
893 #ifdef CONFIG_ALPHA
894 	/* This used to use csum_partial, which was wrong for several
895 	 * reasons including that different results are returned on
896 	 * different architectures.  It isn't critical that we get exactly
897 	 * the same return value as before (we always csum_fold before
898 	 * testing, and that removes any differences).  However as we
899 	 * know that csum_partial always returned a 16bit value on
900 	 * alphas, do a fold to maximise conformity to previous behaviour.
901 	 */
902 	sb->sb_csum = md_csum_fold(disk_csum);
903 #else
904 	sb->sb_csum = disk_csum;
905 #endif
906 	return csum;
907 }
908 
909 
910 /*
911  * Handle superblock details.
912  * We want to be able to handle multiple superblock formats
913  * so we have a common interface to them all, and an array of
914  * different handlers.
915  * We rely on user-space to write the initial superblock, and support
916  * reading and updating of superblocks.
917  * Interface methods are:
918  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
919  *      loads and validates a superblock on dev.
920  *      if refdev != NULL, compare superblocks on both devices
921  *    Return:
922  *      0 - dev has a superblock that is compatible with refdev
923  *      1 - dev has a superblock that is compatible and newer than refdev
924  *          so dev should be used as the refdev in future
925  *     -EINVAL superblock incompatible or invalid
926  *     -othererror e.g. -EIO
927  *
928  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
929  *      Verify that dev is acceptable into mddev.
930  *       The first time, mddev->raid_disks will be 0, and data from
931  *       dev should be merged in.  Subsequent calls check that dev
932  *       is new enough.  Return 0 or -EINVAL
933  *
934  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
935  *     Update the superblock for rdev with data in mddev
936  *     This does not write to disc.
937  *
938  */
939 
940 struct super_type  {
941 	char		    *name;
942 	struct module	    *owner;
943 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
944 					  int minor_version);
945 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
946 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
947 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
948 						sector_t num_sectors);
949 };
950 
951 /*
952  * Check that the given mddev has no bitmap.
953  *
954  * This function is called from the run method of all personalities that do not
955  * support bitmaps. It prints an error message and returns non-zero if mddev
956  * has a bitmap. Otherwise, it returns 0.
957  *
958  */
959 int md_check_no_bitmap(mddev_t *mddev)
960 {
961 	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
962 		return 0;
963 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
964 		mdname(mddev), mddev->pers->name);
965 	return 1;
966 }
967 EXPORT_SYMBOL(md_check_no_bitmap);
968 
969 /*
970  * load_super for 0.90.0
971  */
972 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
973 {
974 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
975 	mdp_super_t *sb;
976 	int ret;
977 
978 	/*
979 	 * Calculate the position of the superblock (512byte sectors),
980 	 * it's at the end of the disk.
981 	 *
982 	 * It also happens to be a multiple of 4Kb.
983 	 */
984 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
985 
986 	ret = read_disk_sb(rdev, MD_SB_BYTES);
987 	if (ret) return ret;
988 
989 	ret = -EINVAL;
990 
991 	bdevname(rdev->bdev, b);
992 	sb = (mdp_super_t*)page_address(rdev->sb_page);
993 
994 	if (sb->md_magic != MD_SB_MAGIC) {
995 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
996 		       b);
997 		goto abort;
998 	}
999 
1000 	if (sb->major_version != 0 ||
1001 	    sb->minor_version < 90 ||
1002 	    sb->minor_version > 91) {
1003 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1004 			sb->major_version, sb->minor_version,
1005 			b);
1006 		goto abort;
1007 	}
1008 
1009 	if (sb->raid_disks <= 0)
1010 		goto abort;
1011 
1012 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1013 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1014 			b);
1015 		goto abort;
1016 	}
1017 
1018 	rdev->preferred_minor = sb->md_minor;
1019 	rdev->data_offset = 0;
1020 	rdev->sb_size = MD_SB_BYTES;
1021 
1022 	if (sb->level == LEVEL_MULTIPATH)
1023 		rdev->desc_nr = -1;
1024 	else
1025 		rdev->desc_nr = sb->this_disk.number;
1026 
1027 	if (!refdev) {
1028 		ret = 1;
1029 	} else {
1030 		__u64 ev1, ev2;
1031 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
1032 		if (!uuid_equal(refsb, sb)) {
1033 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
1034 				b, bdevname(refdev->bdev,b2));
1035 			goto abort;
1036 		}
1037 		if (!sb_equal(refsb, sb)) {
1038 			printk(KERN_WARNING "md: %s has same UUID"
1039 			       " but different superblock to %s\n",
1040 			       b, bdevname(refdev->bdev, b2));
1041 			goto abort;
1042 		}
1043 		ev1 = md_event(sb);
1044 		ev2 = md_event(refsb);
1045 		if (ev1 > ev2)
1046 			ret = 1;
1047 		else
1048 			ret = 0;
1049 	}
1050 	rdev->sectors = rdev->sb_start;
1051 
1052 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
1053 		/* "this cannot possibly happen" ... */
1054 		ret = -EINVAL;
1055 
1056  abort:
1057 	return ret;
1058 }
1059 
1060 /*
1061  * validate_super for 0.90.0
1062  */
1063 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1064 {
1065 	mdp_disk_t *desc;
1066 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
1067 	__u64 ev1 = md_event(sb);
1068 
1069 	rdev->raid_disk = -1;
1070 	clear_bit(Faulty, &rdev->flags);
1071 	clear_bit(In_sync, &rdev->flags);
1072 	clear_bit(WriteMostly, &rdev->flags);
1073 	clear_bit(BarriersNotsupp, &rdev->flags);
1074 
1075 	if (mddev->raid_disks == 0) {
1076 		mddev->major_version = 0;
1077 		mddev->minor_version = sb->minor_version;
1078 		mddev->patch_version = sb->patch_version;
1079 		mddev->external = 0;
1080 		mddev->chunk_sectors = sb->chunk_size >> 9;
1081 		mddev->ctime = sb->ctime;
1082 		mddev->utime = sb->utime;
1083 		mddev->level = sb->level;
1084 		mddev->clevel[0] = 0;
1085 		mddev->layout = sb->layout;
1086 		mddev->raid_disks = sb->raid_disks;
1087 		mddev->dev_sectors = sb->size * 2;
1088 		mddev->events = ev1;
1089 		mddev->bitmap_info.offset = 0;
1090 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1091 
1092 		if (mddev->minor_version >= 91) {
1093 			mddev->reshape_position = sb->reshape_position;
1094 			mddev->delta_disks = sb->delta_disks;
1095 			mddev->new_level = sb->new_level;
1096 			mddev->new_layout = sb->new_layout;
1097 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1098 		} else {
1099 			mddev->reshape_position = MaxSector;
1100 			mddev->delta_disks = 0;
1101 			mddev->new_level = mddev->level;
1102 			mddev->new_layout = mddev->layout;
1103 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1104 		}
1105 
1106 		if (sb->state & (1<<MD_SB_CLEAN))
1107 			mddev->recovery_cp = MaxSector;
1108 		else {
1109 			if (sb->events_hi == sb->cp_events_hi &&
1110 				sb->events_lo == sb->cp_events_lo) {
1111 				mddev->recovery_cp = sb->recovery_cp;
1112 			} else
1113 				mddev->recovery_cp = 0;
1114 		}
1115 
1116 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1117 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1118 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1119 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1120 
1121 		mddev->max_disks = MD_SB_DISKS;
1122 
1123 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1124 		    mddev->bitmap_info.file == NULL)
1125 			mddev->bitmap_info.offset =
1126 				mddev->bitmap_info.default_offset;
1127 
1128 	} else if (mddev->pers == NULL) {
1129 		/* Insist on good event counter while assembling, except
1130 		 * for spares (which don't need an event count) */
1131 		++ev1;
1132 		if (sb->disks[rdev->desc_nr].state & (
1133 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1134 			if (ev1 < mddev->events)
1135 				return -EINVAL;
1136 	} else if (mddev->bitmap) {
1137 		/* if adding to array with a bitmap, then we can accept an
1138 		 * older device ... but not too old.
1139 		 */
1140 		if (ev1 < mddev->bitmap->events_cleared)
1141 			return 0;
1142 	} else {
1143 		if (ev1 < mddev->events)
1144 			/* just a hot-add of a new device, leave raid_disk at -1 */
1145 			return 0;
1146 	}
1147 
1148 	if (mddev->level != LEVEL_MULTIPATH) {
1149 		desc = sb->disks + rdev->desc_nr;
1150 
1151 		if (desc->state & (1<<MD_DISK_FAULTY))
1152 			set_bit(Faulty, &rdev->flags);
1153 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1154 			    desc->raid_disk < mddev->raid_disks */) {
1155 			set_bit(In_sync, &rdev->flags);
1156 			rdev->raid_disk = desc->raid_disk;
1157 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1158 			/* active but not in sync implies recovery up to
1159 			 * reshape position.  We don't know exactly where
1160 			 * that is, so set to zero for now */
1161 			if (mddev->minor_version >= 91) {
1162 				rdev->recovery_offset = 0;
1163 				rdev->raid_disk = desc->raid_disk;
1164 			}
1165 		}
1166 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1167 			set_bit(WriteMostly, &rdev->flags);
1168 	} else /* MULTIPATH are always insync */
1169 		set_bit(In_sync, &rdev->flags);
1170 	return 0;
1171 }
1172 
1173 /*
1174  * sync_super for 0.90.0
1175  */
1176 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1177 {
1178 	mdp_super_t *sb;
1179 	mdk_rdev_t *rdev2;
1180 	int next_spare = mddev->raid_disks;
1181 
1182 
1183 	/* make rdev->sb match mddev data..
1184 	 *
1185 	 * 1/ zero out disks
1186 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1187 	 * 3/ any empty disks < next_spare become removed
1188 	 *
1189 	 * disks[0] gets initialised to REMOVED because
1190 	 * we cannot be sure from other fields if it has
1191 	 * been initialised or not.
1192 	 */
1193 	int i;
1194 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1195 
1196 	rdev->sb_size = MD_SB_BYTES;
1197 
1198 	sb = (mdp_super_t*)page_address(rdev->sb_page);
1199 
1200 	memset(sb, 0, sizeof(*sb));
1201 
1202 	sb->md_magic = MD_SB_MAGIC;
1203 	sb->major_version = mddev->major_version;
1204 	sb->patch_version = mddev->patch_version;
1205 	sb->gvalid_words  = 0; /* ignored */
1206 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1207 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1208 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1209 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1210 
1211 	sb->ctime = mddev->ctime;
1212 	sb->level = mddev->level;
1213 	sb->size = mddev->dev_sectors / 2;
1214 	sb->raid_disks = mddev->raid_disks;
1215 	sb->md_minor = mddev->md_minor;
1216 	sb->not_persistent = 0;
1217 	sb->utime = mddev->utime;
1218 	sb->state = 0;
1219 	sb->events_hi = (mddev->events>>32);
1220 	sb->events_lo = (u32)mddev->events;
1221 
1222 	if (mddev->reshape_position == MaxSector)
1223 		sb->minor_version = 90;
1224 	else {
1225 		sb->minor_version = 91;
1226 		sb->reshape_position = mddev->reshape_position;
1227 		sb->new_level = mddev->new_level;
1228 		sb->delta_disks = mddev->delta_disks;
1229 		sb->new_layout = mddev->new_layout;
1230 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1231 	}
1232 	mddev->minor_version = sb->minor_version;
1233 	if (mddev->in_sync)
1234 	{
1235 		sb->recovery_cp = mddev->recovery_cp;
1236 		sb->cp_events_hi = (mddev->events>>32);
1237 		sb->cp_events_lo = (u32)mddev->events;
1238 		if (mddev->recovery_cp == MaxSector)
1239 			sb->state = (1<< MD_SB_CLEAN);
1240 	} else
1241 		sb->recovery_cp = 0;
1242 
1243 	sb->layout = mddev->layout;
1244 	sb->chunk_size = mddev->chunk_sectors << 9;
1245 
1246 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1247 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1248 
1249 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1250 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1251 		mdp_disk_t *d;
1252 		int desc_nr;
1253 		int is_active = test_bit(In_sync, &rdev2->flags);
1254 
1255 		if (rdev2->raid_disk >= 0 &&
1256 		    sb->minor_version >= 91)
1257 			/* we have nowhere to store the recovery_offset,
1258 			 * but if it is not below the reshape_position,
1259 			 * we can piggy-back on that.
1260 			 */
1261 			is_active = 1;
1262 		if (rdev2->raid_disk < 0 ||
1263 		    test_bit(Faulty, &rdev2->flags))
1264 			is_active = 0;
1265 		if (is_active)
1266 			desc_nr = rdev2->raid_disk;
1267 		else
1268 			desc_nr = next_spare++;
1269 		rdev2->desc_nr = desc_nr;
1270 		d = &sb->disks[rdev2->desc_nr];
1271 		nr_disks++;
1272 		d->number = rdev2->desc_nr;
1273 		d->major = MAJOR(rdev2->bdev->bd_dev);
1274 		d->minor = MINOR(rdev2->bdev->bd_dev);
1275 		if (is_active)
1276 			d->raid_disk = rdev2->raid_disk;
1277 		else
1278 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1279 		if (test_bit(Faulty, &rdev2->flags))
1280 			d->state = (1<<MD_DISK_FAULTY);
1281 		else if (is_active) {
1282 			d->state = (1<<MD_DISK_ACTIVE);
1283 			if (test_bit(In_sync, &rdev2->flags))
1284 				d->state |= (1<<MD_DISK_SYNC);
1285 			active++;
1286 			working++;
1287 		} else {
1288 			d->state = 0;
1289 			spare++;
1290 			working++;
1291 		}
1292 		if (test_bit(WriteMostly, &rdev2->flags))
1293 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1294 	}
1295 	/* now set the "removed" and "faulty" bits on any missing devices */
1296 	for (i=0 ; i < mddev->raid_disks ; i++) {
1297 		mdp_disk_t *d = &sb->disks[i];
1298 		if (d->state == 0 && d->number == 0) {
1299 			d->number = i;
1300 			d->raid_disk = i;
1301 			d->state = (1<<MD_DISK_REMOVED);
1302 			d->state |= (1<<MD_DISK_FAULTY);
1303 			failed++;
1304 		}
1305 	}
1306 	sb->nr_disks = nr_disks;
1307 	sb->active_disks = active;
1308 	sb->working_disks = working;
1309 	sb->failed_disks = failed;
1310 	sb->spare_disks = spare;
1311 
1312 	sb->this_disk = sb->disks[rdev->desc_nr];
1313 	sb->sb_csum = calc_sb_csum(sb);
1314 }
1315 
1316 /*
1317  * rdev_size_change for 0.90.0
1318  */
1319 static unsigned long long
1320 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1321 {
1322 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1323 		return 0; /* component must fit device */
1324 	if (rdev->mddev->bitmap_info.offset)
1325 		return 0; /* can't move bitmap */
1326 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1327 	if (!num_sectors || num_sectors > rdev->sb_start)
1328 		num_sectors = rdev->sb_start;
1329 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1330 		       rdev->sb_page);
1331 	md_super_wait(rdev->mddev);
1332 	return num_sectors / 2; /* kB for sysfs */
1333 }
1334 
1335 
1336 /*
1337  * version 1 superblock
1338  */
1339 
1340 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1341 {
1342 	__le32 disk_csum;
1343 	u32 csum;
1344 	unsigned long long newcsum;
1345 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1346 	__le32 *isuper = (__le32*)sb;
1347 	int i;
1348 
1349 	disk_csum = sb->sb_csum;
1350 	sb->sb_csum = 0;
1351 	newcsum = 0;
1352 	for (i=0; size>=4; size -= 4 )
1353 		newcsum += le32_to_cpu(*isuper++);
1354 
1355 	if (size == 2)
1356 		newcsum += le16_to_cpu(*(__le16*) isuper);
1357 
1358 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1359 	sb->sb_csum = disk_csum;
1360 	return cpu_to_le32(csum);
1361 }
1362 
1363 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1364 {
1365 	struct mdp_superblock_1 *sb;
1366 	int ret;
1367 	sector_t sb_start;
1368 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1369 	int bmask;
1370 
1371 	/*
1372 	 * Calculate the position of the superblock in 512byte sectors.
1373 	 * It is always aligned to a 4K boundary and
1374 	 * depeding on minor_version, it can be:
1375 	 * 0: At least 8K, but less than 12K, from end of device
1376 	 * 1: At start of device
1377 	 * 2: 4K from start of device.
1378 	 */
1379 	switch(minor_version) {
1380 	case 0:
1381 		sb_start = rdev->bdev->bd_inode->i_size >> 9;
1382 		sb_start -= 8*2;
1383 		sb_start &= ~(sector_t)(4*2-1);
1384 		break;
1385 	case 1:
1386 		sb_start = 0;
1387 		break;
1388 	case 2:
1389 		sb_start = 8;
1390 		break;
1391 	default:
1392 		return -EINVAL;
1393 	}
1394 	rdev->sb_start = sb_start;
1395 
1396 	/* superblock is rarely larger than 1K, but it can be larger,
1397 	 * and it is safe to read 4k, so we do that
1398 	 */
1399 	ret = read_disk_sb(rdev, 4096);
1400 	if (ret) return ret;
1401 
1402 
1403 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1404 
1405 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1406 	    sb->major_version != cpu_to_le32(1) ||
1407 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1408 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1409 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1410 		return -EINVAL;
1411 
1412 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1413 		printk("md: invalid superblock checksum on %s\n",
1414 			bdevname(rdev->bdev,b));
1415 		return -EINVAL;
1416 	}
1417 	if (le64_to_cpu(sb->data_size) < 10) {
1418 		printk("md: data_size too small on %s\n",
1419 		       bdevname(rdev->bdev,b));
1420 		return -EINVAL;
1421 	}
1422 
1423 	rdev->preferred_minor = 0xffff;
1424 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1425 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1426 
1427 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1428 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1429 	if (rdev->sb_size & bmask)
1430 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1431 
1432 	if (minor_version
1433 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1434 		return -EINVAL;
1435 
1436 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1437 		rdev->desc_nr = -1;
1438 	else
1439 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1440 
1441 	if (!refdev) {
1442 		ret = 1;
1443 	} else {
1444 		__u64 ev1, ev2;
1445 		struct mdp_superblock_1 *refsb =
1446 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1447 
1448 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1449 		    sb->level != refsb->level ||
1450 		    sb->layout != refsb->layout ||
1451 		    sb->chunksize != refsb->chunksize) {
1452 			printk(KERN_WARNING "md: %s has strangely different"
1453 				" superblock to %s\n",
1454 				bdevname(rdev->bdev,b),
1455 				bdevname(refdev->bdev,b2));
1456 			return -EINVAL;
1457 		}
1458 		ev1 = le64_to_cpu(sb->events);
1459 		ev2 = le64_to_cpu(refsb->events);
1460 
1461 		if (ev1 > ev2)
1462 			ret = 1;
1463 		else
1464 			ret = 0;
1465 	}
1466 	if (minor_version)
1467 		rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
1468 			le64_to_cpu(sb->data_offset);
1469 	else
1470 		rdev->sectors = rdev->sb_start;
1471 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1472 		return -EINVAL;
1473 	rdev->sectors = le64_to_cpu(sb->data_size);
1474 	if (le64_to_cpu(sb->size) > rdev->sectors)
1475 		return -EINVAL;
1476 	return ret;
1477 }
1478 
1479 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1480 {
1481 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1482 	__u64 ev1 = le64_to_cpu(sb->events);
1483 
1484 	rdev->raid_disk = -1;
1485 	clear_bit(Faulty, &rdev->flags);
1486 	clear_bit(In_sync, &rdev->flags);
1487 	clear_bit(WriteMostly, &rdev->flags);
1488 	clear_bit(BarriersNotsupp, &rdev->flags);
1489 
1490 	if (mddev->raid_disks == 0) {
1491 		mddev->major_version = 1;
1492 		mddev->patch_version = 0;
1493 		mddev->external = 0;
1494 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1495 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1496 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1497 		mddev->level = le32_to_cpu(sb->level);
1498 		mddev->clevel[0] = 0;
1499 		mddev->layout = le32_to_cpu(sb->layout);
1500 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1501 		mddev->dev_sectors = le64_to_cpu(sb->size);
1502 		mddev->events = ev1;
1503 		mddev->bitmap_info.offset = 0;
1504 		mddev->bitmap_info.default_offset = 1024 >> 9;
1505 
1506 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1507 		memcpy(mddev->uuid, sb->set_uuid, 16);
1508 
1509 		mddev->max_disks =  (4096-256)/2;
1510 
1511 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1512 		    mddev->bitmap_info.file == NULL )
1513 			mddev->bitmap_info.offset =
1514 				(__s32)le32_to_cpu(sb->bitmap_offset);
1515 
1516 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1517 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1518 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1519 			mddev->new_level = le32_to_cpu(sb->new_level);
1520 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1521 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1522 		} else {
1523 			mddev->reshape_position = MaxSector;
1524 			mddev->delta_disks = 0;
1525 			mddev->new_level = mddev->level;
1526 			mddev->new_layout = mddev->layout;
1527 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1528 		}
1529 
1530 	} else if (mddev->pers == NULL) {
1531 		/* Insist of good event counter while assembling, except for
1532 		 * spares (which don't need an event count) */
1533 		++ev1;
1534 		if (rdev->desc_nr >= 0 &&
1535 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1536 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1537 			if (ev1 < mddev->events)
1538 				return -EINVAL;
1539 	} else if (mddev->bitmap) {
1540 		/* If adding to array with a bitmap, then we can accept an
1541 		 * older device, but not too old.
1542 		 */
1543 		if (ev1 < mddev->bitmap->events_cleared)
1544 			return 0;
1545 	} else {
1546 		if (ev1 < mddev->events)
1547 			/* just a hot-add of a new device, leave raid_disk at -1 */
1548 			return 0;
1549 	}
1550 	if (mddev->level != LEVEL_MULTIPATH) {
1551 		int role;
1552 		if (rdev->desc_nr < 0 ||
1553 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1554 			role = 0xffff;
1555 			rdev->desc_nr = -1;
1556 		} else
1557 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1558 		switch(role) {
1559 		case 0xffff: /* spare */
1560 			break;
1561 		case 0xfffe: /* faulty */
1562 			set_bit(Faulty, &rdev->flags);
1563 			break;
1564 		default:
1565 			if ((le32_to_cpu(sb->feature_map) &
1566 			     MD_FEATURE_RECOVERY_OFFSET))
1567 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1568 			else
1569 				set_bit(In_sync, &rdev->flags);
1570 			rdev->raid_disk = role;
1571 			break;
1572 		}
1573 		if (sb->devflags & WriteMostly1)
1574 			set_bit(WriteMostly, &rdev->flags);
1575 	} else /* MULTIPATH are always insync */
1576 		set_bit(In_sync, &rdev->flags);
1577 
1578 	return 0;
1579 }
1580 
1581 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1582 {
1583 	struct mdp_superblock_1 *sb;
1584 	mdk_rdev_t *rdev2;
1585 	int max_dev, i;
1586 	/* make rdev->sb match mddev and rdev data. */
1587 
1588 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1589 
1590 	sb->feature_map = 0;
1591 	sb->pad0 = 0;
1592 	sb->recovery_offset = cpu_to_le64(0);
1593 	memset(sb->pad1, 0, sizeof(sb->pad1));
1594 	memset(sb->pad2, 0, sizeof(sb->pad2));
1595 	memset(sb->pad3, 0, sizeof(sb->pad3));
1596 
1597 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1598 	sb->events = cpu_to_le64(mddev->events);
1599 	if (mddev->in_sync)
1600 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1601 	else
1602 		sb->resync_offset = cpu_to_le64(0);
1603 
1604 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1605 
1606 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1607 	sb->size = cpu_to_le64(mddev->dev_sectors);
1608 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1609 	sb->level = cpu_to_le32(mddev->level);
1610 	sb->layout = cpu_to_le32(mddev->layout);
1611 
1612 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1613 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1614 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1615 	}
1616 
1617 	if (rdev->raid_disk >= 0 &&
1618 	    !test_bit(In_sync, &rdev->flags)) {
1619 		sb->feature_map |=
1620 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1621 		sb->recovery_offset =
1622 			cpu_to_le64(rdev->recovery_offset);
1623 	}
1624 
1625 	if (mddev->reshape_position != MaxSector) {
1626 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1627 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1628 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1629 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1630 		sb->new_level = cpu_to_le32(mddev->new_level);
1631 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1632 	}
1633 
1634 	max_dev = 0;
1635 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1636 		if (rdev2->desc_nr+1 > max_dev)
1637 			max_dev = rdev2->desc_nr+1;
1638 
1639 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1640 		int bmask;
1641 		sb->max_dev = cpu_to_le32(max_dev);
1642 		rdev->sb_size = max_dev * 2 + 256;
1643 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1644 		if (rdev->sb_size & bmask)
1645 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1646 	} else
1647 		max_dev = le32_to_cpu(sb->max_dev);
1648 
1649 	for (i=0; i<max_dev;i++)
1650 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1651 
1652 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1653 		i = rdev2->desc_nr;
1654 		if (test_bit(Faulty, &rdev2->flags))
1655 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1656 		else if (test_bit(In_sync, &rdev2->flags))
1657 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1658 		else if (rdev2->raid_disk >= 0)
1659 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1660 		else
1661 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1662 	}
1663 
1664 	sb->sb_csum = calc_sb_1_csum(sb);
1665 }
1666 
1667 static unsigned long long
1668 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1669 {
1670 	struct mdp_superblock_1 *sb;
1671 	sector_t max_sectors;
1672 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1673 		return 0; /* component must fit device */
1674 	if (rdev->sb_start < rdev->data_offset) {
1675 		/* minor versions 1 and 2; superblock before data */
1676 		max_sectors = rdev->bdev->bd_inode->i_size >> 9;
1677 		max_sectors -= rdev->data_offset;
1678 		if (!num_sectors || num_sectors > max_sectors)
1679 			num_sectors = max_sectors;
1680 	} else if (rdev->mddev->bitmap_info.offset) {
1681 		/* minor version 0 with bitmap we can't move */
1682 		return 0;
1683 	} else {
1684 		/* minor version 0; superblock after data */
1685 		sector_t sb_start;
1686 		sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
1687 		sb_start &= ~(sector_t)(4*2 - 1);
1688 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1689 		if (!num_sectors || num_sectors > max_sectors)
1690 			num_sectors = max_sectors;
1691 		rdev->sb_start = sb_start;
1692 	}
1693 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1694 	sb->data_size = cpu_to_le64(num_sectors);
1695 	sb->super_offset = rdev->sb_start;
1696 	sb->sb_csum = calc_sb_1_csum(sb);
1697 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1698 		       rdev->sb_page);
1699 	md_super_wait(rdev->mddev);
1700 	return num_sectors / 2; /* kB for sysfs */
1701 }
1702 
1703 static struct super_type super_types[] = {
1704 	[0] = {
1705 		.name	= "0.90.0",
1706 		.owner	= THIS_MODULE,
1707 		.load_super	    = super_90_load,
1708 		.validate_super	    = super_90_validate,
1709 		.sync_super	    = super_90_sync,
1710 		.rdev_size_change   = super_90_rdev_size_change,
1711 	},
1712 	[1] = {
1713 		.name	= "md-1",
1714 		.owner	= THIS_MODULE,
1715 		.load_super	    = super_1_load,
1716 		.validate_super	    = super_1_validate,
1717 		.sync_super	    = super_1_sync,
1718 		.rdev_size_change   = super_1_rdev_size_change,
1719 	},
1720 };
1721 
1722 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1723 {
1724 	mdk_rdev_t *rdev, *rdev2;
1725 
1726 	rcu_read_lock();
1727 	rdev_for_each_rcu(rdev, mddev1)
1728 		rdev_for_each_rcu(rdev2, mddev2)
1729 			if (rdev->bdev->bd_contains ==
1730 			    rdev2->bdev->bd_contains) {
1731 				rcu_read_unlock();
1732 				return 1;
1733 			}
1734 	rcu_read_unlock();
1735 	return 0;
1736 }
1737 
1738 static LIST_HEAD(pending_raid_disks);
1739 
1740 /*
1741  * Try to register data integrity profile for an mddev
1742  *
1743  * This is called when an array is started and after a disk has been kicked
1744  * from the array. It only succeeds if all working and active component devices
1745  * are integrity capable with matching profiles.
1746  */
1747 int md_integrity_register(mddev_t *mddev)
1748 {
1749 	mdk_rdev_t *rdev, *reference = NULL;
1750 
1751 	if (list_empty(&mddev->disks))
1752 		return 0; /* nothing to do */
1753 	if (blk_get_integrity(mddev->gendisk))
1754 		return 0; /* already registered */
1755 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1756 		/* skip spares and non-functional disks */
1757 		if (test_bit(Faulty, &rdev->flags))
1758 			continue;
1759 		if (rdev->raid_disk < 0)
1760 			continue;
1761 		/*
1762 		 * If at least one rdev is not integrity capable, we can not
1763 		 * enable data integrity for the md device.
1764 		 */
1765 		if (!bdev_get_integrity(rdev->bdev))
1766 			return -EINVAL;
1767 		if (!reference) {
1768 			/* Use the first rdev as the reference */
1769 			reference = rdev;
1770 			continue;
1771 		}
1772 		/* does this rdev's profile match the reference profile? */
1773 		if (blk_integrity_compare(reference->bdev->bd_disk,
1774 				rdev->bdev->bd_disk) < 0)
1775 			return -EINVAL;
1776 	}
1777 	/*
1778 	 * All component devices are integrity capable and have matching
1779 	 * profiles, register the common profile for the md device.
1780 	 */
1781 	if (blk_integrity_register(mddev->gendisk,
1782 			bdev_get_integrity(reference->bdev)) != 0) {
1783 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1784 			mdname(mddev));
1785 		return -EINVAL;
1786 	}
1787 	printk(KERN_NOTICE "md: data integrity on %s enabled\n",
1788 		mdname(mddev));
1789 	return 0;
1790 }
1791 EXPORT_SYMBOL(md_integrity_register);
1792 
1793 /* Disable data integrity if non-capable/non-matching disk is being added */
1794 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1795 {
1796 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1797 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1798 
1799 	if (!bi_mddev) /* nothing to do */
1800 		return;
1801 	if (rdev->raid_disk < 0) /* skip spares */
1802 		return;
1803 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1804 					     rdev->bdev->bd_disk) >= 0)
1805 		return;
1806 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1807 	blk_integrity_unregister(mddev->gendisk);
1808 }
1809 EXPORT_SYMBOL(md_integrity_add_rdev);
1810 
1811 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1812 {
1813 	char b[BDEVNAME_SIZE];
1814 	struct kobject *ko;
1815 	char *s;
1816 	int err;
1817 
1818 	if (rdev->mddev) {
1819 		MD_BUG();
1820 		return -EINVAL;
1821 	}
1822 
1823 	/* prevent duplicates */
1824 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1825 		return -EEXIST;
1826 
1827 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
1828 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
1829 			rdev->sectors < mddev->dev_sectors)) {
1830 		if (mddev->pers) {
1831 			/* Cannot change size, so fail
1832 			 * If mddev->level <= 0, then we don't care
1833 			 * about aligning sizes (e.g. linear)
1834 			 */
1835 			if (mddev->level > 0)
1836 				return -ENOSPC;
1837 		} else
1838 			mddev->dev_sectors = rdev->sectors;
1839 	}
1840 
1841 	/* Verify rdev->desc_nr is unique.
1842 	 * If it is -1, assign a free number, else
1843 	 * check number is not in use
1844 	 */
1845 	if (rdev->desc_nr < 0) {
1846 		int choice = 0;
1847 		if (mddev->pers) choice = mddev->raid_disks;
1848 		while (find_rdev_nr(mddev, choice))
1849 			choice++;
1850 		rdev->desc_nr = choice;
1851 	} else {
1852 		if (find_rdev_nr(mddev, rdev->desc_nr))
1853 			return -EBUSY;
1854 	}
1855 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1856 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1857 		       mdname(mddev), mddev->max_disks);
1858 		return -EBUSY;
1859 	}
1860 	bdevname(rdev->bdev,b);
1861 	while ( (s=strchr(b, '/')) != NULL)
1862 		*s = '!';
1863 
1864 	rdev->mddev = mddev;
1865 	printk(KERN_INFO "md: bind<%s>\n", b);
1866 
1867 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1868 		goto fail;
1869 
1870 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1871 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
1872 		/* failure here is OK */;
1873 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
1874 
1875 	list_add_rcu(&rdev->same_set, &mddev->disks);
1876 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1877 
1878 	/* May as well allow recovery to be retried once */
1879 	mddev->recovery_disabled = 0;
1880 
1881 	return 0;
1882 
1883  fail:
1884 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1885 	       b, mdname(mddev));
1886 	return err;
1887 }
1888 
1889 static void md_delayed_delete(struct work_struct *ws)
1890 {
1891 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1892 	kobject_del(&rdev->kobj);
1893 	kobject_put(&rdev->kobj);
1894 }
1895 
1896 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1897 {
1898 	char b[BDEVNAME_SIZE];
1899 	if (!rdev->mddev) {
1900 		MD_BUG();
1901 		return;
1902 	}
1903 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1904 	list_del_rcu(&rdev->same_set);
1905 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1906 	rdev->mddev = NULL;
1907 	sysfs_remove_link(&rdev->kobj, "block");
1908 	sysfs_put(rdev->sysfs_state);
1909 	rdev->sysfs_state = NULL;
1910 	/* We need to delay this, otherwise we can deadlock when
1911 	 * writing to 'remove' to "dev/state".  We also need
1912 	 * to delay it due to rcu usage.
1913 	 */
1914 	synchronize_rcu();
1915 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1916 	kobject_get(&rdev->kobj);
1917 	schedule_work(&rdev->del_work);
1918 }
1919 
1920 /*
1921  * prevent the device from being mounted, repartitioned or
1922  * otherwise reused by a RAID array (or any other kernel
1923  * subsystem), by bd_claiming the device.
1924  */
1925 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1926 {
1927 	int err = 0;
1928 	struct block_device *bdev;
1929 	char b[BDEVNAME_SIZE];
1930 
1931 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1932 	if (IS_ERR(bdev)) {
1933 		printk(KERN_ERR "md: could not open %s.\n",
1934 			__bdevname(dev, b));
1935 		return PTR_ERR(bdev);
1936 	}
1937 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1938 	if (err) {
1939 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1940 			bdevname(bdev, b));
1941 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1942 		return err;
1943 	}
1944 	if (!shared)
1945 		set_bit(AllReserved, &rdev->flags);
1946 	rdev->bdev = bdev;
1947 	return err;
1948 }
1949 
1950 static void unlock_rdev(mdk_rdev_t *rdev)
1951 {
1952 	struct block_device *bdev = rdev->bdev;
1953 	rdev->bdev = NULL;
1954 	if (!bdev)
1955 		MD_BUG();
1956 	bd_release(bdev);
1957 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1958 }
1959 
1960 void md_autodetect_dev(dev_t dev);
1961 
1962 static void export_rdev(mdk_rdev_t * rdev)
1963 {
1964 	char b[BDEVNAME_SIZE];
1965 	printk(KERN_INFO "md: export_rdev(%s)\n",
1966 		bdevname(rdev->bdev,b));
1967 	if (rdev->mddev)
1968 		MD_BUG();
1969 	free_disk_sb(rdev);
1970 #ifndef MODULE
1971 	if (test_bit(AutoDetected, &rdev->flags))
1972 		md_autodetect_dev(rdev->bdev->bd_dev);
1973 #endif
1974 	unlock_rdev(rdev);
1975 	kobject_put(&rdev->kobj);
1976 }
1977 
1978 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1979 {
1980 	unbind_rdev_from_array(rdev);
1981 	export_rdev(rdev);
1982 }
1983 
1984 static void export_array(mddev_t *mddev)
1985 {
1986 	mdk_rdev_t *rdev, *tmp;
1987 
1988 	rdev_for_each(rdev, tmp, mddev) {
1989 		if (!rdev->mddev) {
1990 			MD_BUG();
1991 			continue;
1992 		}
1993 		kick_rdev_from_array(rdev);
1994 	}
1995 	if (!list_empty(&mddev->disks))
1996 		MD_BUG();
1997 	mddev->raid_disks = 0;
1998 	mddev->major_version = 0;
1999 }
2000 
2001 static void print_desc(mdp_disk_t *desc)
2002 {
2003 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2004 		desc->major,desc->minor,desc->raid_disk,desc->state);
2005 }
2006 
2007 static void print_sb_90(mdp_super_t *sb)
2008 {
2009 	int i;
2010 
2011 	printk(KERN_INFO
2012 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2013 		sb->major_version, sb->minor_version, sb->patch_version,
2014 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2015 		sb->ctime);
2016 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2017 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2018 		sb->md_minor, sb->layout, sb->chunk_size);
2019 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2020 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2021 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2022 		sb->failed_disks, sb->spare_disks,
2023 		sb->sb_csum, (unsigned long)sb->events_lo);
2024 
2025 	printk(KERN_INFO);
2026 	for (i = 0; i < MD_SB_DISKS; i++) {
2027 		mdp_disk_t *desc;
2028 
2029 		desc = sb->disks + i;
2030 		if (desc->number || desc->major || desc->minor ||
2031 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2032 			printk("     D %2d: ", i);
2033 			print_desc(desc);
2034 		}
2035 	}
2036 	printk(KERN_INFO "md:     THIS: ");
2037 	print_desc(&sb->this_disk);
2038 }
2039 
2040 static void print_sb_1(struct mdp_superblock_1 *sb)
2041 {
2042 	__u8 *uuid;
2043 
2044 	uuid = sb->set_uuid;
2045 	printk(KERN_INFO
2046 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2047 	       "md:    Name: \"%s\" CT:%llu\n",
2048 		le32_to_cpu(sb->major_version),
2049 		le32_to_cpu(sb->feature_map),
2050 		uuid,
2051 		sb->set_name,
2052 		(unsigned long long)le64_to_cpu(sb->ctime)
2053 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2054 
2055 	uuid = sb->device_uuid;
2056 	printk(KERN_INFO
2057 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2058 			" RO:%llu\n"
2059 	       "md:     Dev:%08x UUID: %pU\n"
2060 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2061 	       "md:         (MaxDev:%u) \n",
2062 		le32_to_cpu(sb->level),
2063 		(unsigned long long)le64_to_cpu(sb->size),
2064 		le32_to_cpu(sb->raid_disks),
2065 		le32_to_cpu(sb->layout),
2066 		le32_to_cpu(sb->chunksize),
2067 		(unsigned long long)le64_to_cpu(sb->data_offset),
2068 		(unsigned long long)le64_to_cpu(sb->data_size),
2069 		(unsigned long long)le64_to_cpu(sb->super_offset),
2070 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2071 		le32_to_cpu(sb->dev_number),
2072 		uuid,
2073 		sb->devflags,
2074 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2075 		(unsigned long long)le64_to_cpu(sb->events),
2076 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2077 		le32_to_cpu(sb->sb_csum),
2078 		le32_to_cpu(sb->max_dev)
2079 		);
2080 }
2081 
2082 static void print_rdev(mdk_rdev_t *rdev, int major_version)
2083 {
2084 	char b[BDEVNAME_SIZE];
2085 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2086 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2087 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2088 	        rdev->desc_nr);
2089 	if (rdev->sb_loaded) {
2090 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2091 		switch (major_version) {
2092 		case 0:
2093 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
2094 			break;
2095 		case 1:
2096 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
2097 			break;
2098 		}
2099 	} else
2100 		printk(KERN_INFO "md: no rdev superblock!\n");
2101 }
2102 
2103 static void md_print_devices(void)
2104 {
2105 	struct list_head *tmp;
2106 	mdk_rdev_t *rdev;
2107 	mddev_t *mddev;
2108 	char b[BDEVNAME_SIZE];
2109 
2110 	printk("\n");
2111 	printk("md:	**********************************\n");
2112 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2113 	printk("md:	**********************************\n");
2114 	for_each_mddev(mddev, tmp) {
2115 
2116 		if (mddev->bitmap)
2117 			bitmap_print_sb(mddev->bitmap);
2118 		else
2119 			printk("%s: ", mdname(mddev));
2120 		list_for_each_entry(rdev, &mddev->disks, same_set)
2121 			printk("<%s>", bdevname(rdev->bdev,b));
2122 		printk("\n");
2123 
2124 		list_for_each_entry(rdev, &mddev->disks, same_set)
2125 			print_rdev(rdev, mddev->major_version);
2126 	}
2127 	printk("md:	**********************************\n");
2128 	printk("\n");
2129 }
2130 
2131 
2132 static void sync_sbs(mddev_t * mddev, int nospares)
2133 {
2134 	/* Update each superblock (in-memory image), but
2135 	 * if we are allowed to, skip spares which already
2136 	 * have the right event counter, or have one earlier
2137 	 * (which would mean they aren't being marked as dirty
2138 	 * with the rest of the array)
2139 	 */
2140 	mdk_rdev_t *rdev;
2141 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2142 		if (rdev->sb_events == mddev->events ||
2143 		    (nospares &&
2144 		     rdev->raid_disk < 0 &&
2145 		     rdev->sb_events+1 == mddev->events)) {
2146 			/* Don't update this superblock */
2147 			rdev->sb_loaded = 2;
2148 		} else {
2149 			super_types[mddev->major_version].
2150 				sync_super(mddev, rdev);
2151 			rdev->sb_loaded = 1;
2152 		}
2153 	}
2154 }
2155 
2156 static void md_update_sb(mddev_t * mddev, int force_change)
2157 {
2158 	mdk_rdev_t *rdev;
2159 	int sync_req;
2160 	int nospares = 0;
2161 
2162 repeat:
2163 	/* First make sure individual recovery_offsets are correct */
2164 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2165 		if (rdev->raid_disk >= 0 &&
2166 		    mddev->delta_disks >= 0 &&
2167 		    !test_bit(In_sync, &rdev->flags) &&
2168 		    mddev->curr_resync_completed > rdev->recovery_offset)
2169 				rdev->recovery_offset = mddev->curr_resync_completed;
2170 
2171 	}
2172 	if (!mddev->persistent) {
2173 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2174 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2175 		wake_up(&mddev->sb_wait);
2176 		return;
2177 	}
2178 
2179 	spin_lock_irq(&mddev->write_lock);
2180 
2181 	mddev->utime = get_seconds();
2182 
2183 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2184 		force_change = 1;
2185 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2186 		/* just a clean<-> dirty transition, possibly leave spares alone,
2187 		 * though if events isn't the right even/odd, we will have to do
2188 		 * spares after all
2189 		 */
2190 		nospares = 1;
2191 	if (force_change)
2192 		nospares = 0;
2193 	if (mddev->degraded)
2194 		/* If the array is degraded, then skipping spares is both
2195 		 * dangerous and fairly pointless.
2196 		 * Dangerous because a device that was removed from the array
2197 		 * might have a event_count that still looks up-to-date,
2198 		 * so it can be re-added without a resync.
2199 		 * Pointless because if there are any spares to skip,
2200 		 * then a recovery will happen and soon that array won't
2201 		 * be degraded any more and the spare can go back to sleep then.
2202 		 */
2203 		nospares = 0;
2204 
2205 	sync_req = mddev->in_sync;
2206 
2207 	/* If this is just a dirty<->clean transition, and the array is clean
2208 	 * and 'events' is odd, we can roll back to the previous clean state */
2209 	if (nospares
2210 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2211 	    && mddev->can_decrease_events
2212 	    && mddev->events != 1) {
2213 		mddev->events--;
2214 		mddev->can_decrease_events = 0;
2215 	} else {
2216 		/* otherwise we have to go forward and ... */
2217 		mddev->events ++;
2218 		mddev->can_decrease_events = nospares;
2219 	}
2220 
2221 	if (!mddev->events) {
2222 		/*
2223 		 * oops, this 64-bit counter should never wrap.
2224 		 * Either we are in around ~1 trillion A.C., assuming
2225 		 * 1 reboot per second, or we have a bug:
2226 		 */
2227 		MD_BUG();
2228 		mddev->events --;
2229 	}
2230 	sync_sbs(mddev, nospares);
2231 	spin_unlock_irq(&mddev->write_lock);
2232 
2233 	dprintk(KERN_INFO
2234 		"md: updating %s RAID superblock on device (in sync %d)\n",
2235 		mdname(mddev),mddev->in_sync);
2236 
2237 	bitmap_update_sb(mddev->bitmap);
2238 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2239 		char b[BDEVNAME_SIZE];
2240 		dprintk(KERN_INFO "md: ");
2241 		if (rdev->sb_loaded != 1)
2242 			continue; /* no noise on spare devices */
2243 		if (test_bit(Faulty, &rdev->flags))
2244 			dprintk("(skipping faulty ");
2245 
2246 		dprintk("%s ", bdevname(rdev->bdev,b));
2247 		if (!test_bit(Faulty, &rdev->flags)) {
2248 			md_super_write(mddev,rdev,
2249 				       rdev->sb_start, rdev->sb_size,
2250 				       rdev->sb_page);
2251 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2252 				bdevname(rdev->bdev,b),
2253 				(unsigned long long)rdev->sb_start);
2254 			rdev->sb_events = mddev->events;
2255 
2256 		} else
2257 			dprintk(")\n");
2258 		if (mddev->level == LEVEL_MULTIPATH)
2259 			/* only need to write one superblock... */
2260 			break;
2261 	}
2262 	md_super_wait(mddev);
2263 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2264 
2265 	spin_lock_irq(&mddev->write_lock);
2266 	if (mddev->in_sync != sync_req ||
2267 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2268 		/* have to write it out again */
2269 		spin_unlock_irq(&mddev->write_lock);
2270 		goto repeat;
2271 	}
2272 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2273 	spin_unlock_irq(&mddev->write_lock);
2274 	wake_up(&mddev->sb_wait);
2275 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2276 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2277 
2278 }
2279 
2280 /* words written to sysfs files may, or may not, be \n terminated.
2281  * We want to accept with case. For this we use cmd_match.
2282  */
2283 static int cmd_match(const char *cmd, const char *str)
2284 {
2285 	/* See if cmd, written into a sysfs file, matches
2286 	 * str.  They must either be the same, or cmd can
2287 	 * have a trailing newline
2288 	 */
2289 	while (*cmd && *str && *cmd == *str) {
2290 		cmd++;
2291 		str++;
2292 	}
2293 	if (*cmd == '\n')
2294 		cmd++;
2295 	if (*str || *cmd)
2296 		return 0;
2297 	return 1;
2298 }
2299 
2300 struct rdev_sysfs_entry {
2301 	struct attribute attr;
2302 	ssize_t (*show)(mdk_rdev_t *, char *);
2303 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2304 };
2305 
2306 static ssize_t
2307 state_show(mdk_rdev_t *rdev, char *page)
2308 {
2309 	char *sep = "";
2310 	size_t len = 0;
2311 
2312 	if (test_bit(Faulty, &rdev->flags)) {
2313 		len+= sprintf(page+len, "%sfaulty",sep);
2314 		sep = ",";
2315 	}
2316 	if (test_bit(In_sync, &rdev->flags)) {
2317 		len += sprintf(page+len, "%sin_sync",sep);
2318 		sep = ",";
2319 	}
2320 	if (test_bit(WriteMostly, &rdev->flags)) {
2321 		len += sprintf(page+len, "%swrite_mostly",sep);
2322 		sep = ",";
2323 	}
2324 	if (test_bit(Blocked, &rdev->flags)) {
2325 		len += sprintf(page+len, "%sblocked", sep);
2326 		sep = ",";
2327 	}
2328 	if (!test_bit(Faulty, &rdev->flags) &&
2329 	    !test_bit(In_sync, &rdev->flags)) {
2330 		len += sprintf(page+len, "%sspare", sep);
2331 		sep = ",";
2332 	}
2333 	return len+sprintf(page+len, "\n");
2334 }
2335 
2336 static ssize_t
2337 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2338 {
2339 	/* can write
2340 	 *  faulty  - simulates and error
2341 	 *  remove  - disconnects the device
2342 	 *  writemostly - sets write_mostly
2343 	 *  -writemostly - clears write_mostly
2344 	 *  blocked - sets the Blocked flag
2345 	 *  -blocked - clears the Blocked flag
2346 	 *  insync - sets Insync providing device isn't active
2347 	 */
2348 	int err = -EINVAL;
2349 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2350 		md_error(rdev->mddev, rdev);
2351 		err = 0;
2352 	} else if (cmd_match(buf, "remove")) {
2353 		if (rdev->raid_disk >= 0)
2354 			err = -EBUSY;
2355 		else {
2356 			mddev_t *mddev = rdev->mddev;
2357 			kick_rdev_from_array(rdev);
2358 			if (mddev->pers)
2359 				md_update_sb(mddev, 1);
2360 			md_new_event(mddev);
2361 			err = 0;
2362 		}
2363 	} else if (cmd_match(buf, "writemostly")) {
2364 		set_bit(WriteMostly, &rdev->flags);
2365 		err = 0;
2366 	} else if (cmd_match(buf, "-writemostly")) {
2367 		clear_bit(WriteMostly, &rdev->flags);
2368 		err = 0;
2369 	} else if (cmd_match(buf, "blocked")) {
2370 		set_bit(Blocked, &rdev->flags);
2371 		err = 0;
2372 	} else if (cmd_match(buf, "-blocked")) {
2373 		clear_bit(Blocked, &rdev->flags);
2374 		wake_up(&rdev->blocked_wait);
2375 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2376 		md_wakeup_thread(rdev->mddev->thread);
2377 
2378 		err = 0;
2379 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2380 		set_bit(In_sync, &rdev->flags);
2381 		err = 0;
2382 	}
2383 	if (!err)
2384 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2385 	return err ? err : len;
2386 }
2387 static struct rdev_sysfs_entry rdev_state =
2388 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2389 
2390 static ssize_t
2391 errors_show(mdk_rdev_t *rdev, char *page)
2392 {
2393 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2394 }
2395 
2396 static ssize_t
2397 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2398 {
2399 	char *e;
2400 	unsigned long n = simple_strtoul(buf, &e, 10);
2401 	if (*buf && (*e == 0 || *e == '\n')) {
2402 		atomic_set(&rdev->corrected_errors, n);
2403 		return len;
2404 	}
2405 	return -EINVAL;
2406 }
2407 static struct rdev_sysfs_entry rdev_errors =
2408 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2409 
2410 static ssize_t
2411 slot_show(mdk_rdev_t *rdev, char *page)
2412 {
2413 	if (rdev->raid_disk < 0)
2414 		return sprintf(page, "none\n");
2415 	else
2416 		return sprintf(page, "%d\n", rdev->raid_disk);
2417 }
2418 
2419 static ssize_t
2420 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2421 {
2422 	char *e;
2423 	int err;
2424 	char nm[20];
2425 	int slot = simple_strtoul(buf, &e, 10);
2426 	if (strncmp(buf, "none", 4)==0)
2427 		slot = -1;
2428 	else if (e==buf || (*e && *e!= '\n'))
2429 		return -EINVAL;
2430 	if (rdev->mddev->pers && slot == -1) {
2431 		/* Setting 'slot' on an active array requires also
2432 		 * updating the 'rd%d' link, and communicating
2433 		 * with the personality with ->hot_*_disk.
2434 		 * For now we only support removing
2435 		 * failed/spare devices.  This normally happens automatically,
2436 		 * but not when the metadata is externally managed.
2437 		 */
2438 		if (rdev->raid_disk == -1)
2439 			return -EEXIST;
2440 		/* personality does all needed checks */
2441 		if (rdev->mddev->pers->hot_add_disk == NULL)
2442 			return -EINVAL;
2443 		err = rdev->mddev->pers->
2444 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2445 		if (err)
2446 			return err;
2447 		sprintf(nm, "rd%d", rdev->raid_disk);
2448 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2449 		rdev->raid_disk = -1;
2450 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2451 		md_wakeup_thread(rdev->mddev->thread);
2452 	} else if (rdev->mddev->pers) {
2453 		mdk_rdev_t *rdev2;
2454 		/* Activating a spare .. or possibly reactivating
2455 		 * if we ever get bitmaps working here.
2456 		 */
2457 
2458 		if (rdev->raid_disk != -1)
2459 			return -EBUSY;
2460 
2461 		if (rdev->mddev->pers->hot_add_disk == NULL)
2462 			return -EINVAL;
2463 
2464 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2465 			if (rdev2->raid_disk == slot)
2466 				return -EEXIST;
2467 
2468 		rdev->raid_disk = slot;
2469 		if (test_bit(In_sync, &rdev->flags))
2470 			rdev->saved_raid_disk = slot;
2471 		else
2472 			rdev->saved_raid_disk = -1;
2473 		err = rdev->mddev->pers->
2474 			hot_add_disk(rdev->mddev, rdev);
2475 		if (err) {
2476 			rdev->raid_disk = -1;
2477 			return err;
2478 		} else
2479 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2480 		sprintf(nm, "rd%d", rdev->raid_disk);
2481 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2482 			/* failure here is OK */;
2483 		/* don't wakeup anyone, leave that to userspace. */
2484 	} else {
2485 		if (slot >= rdev->mddev->raid_disks)
2486 			return -ENOSPC;
2487 		rdev->raid_disk = slot;
2488 		/* assume it is working */
2489 		clear_bit(Faulty, &rdev->flags);
2490 		clear_bit(WriteMostly, &rdev->flags);
2491 		set_bit(In_sync, &rdev->flags);
2492 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2493 	}
2494 	return len;
2495 }
2496 
2497 
2498 static struct rdev_sysfs_entry rdev_slot =
2499 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2500 
2501 static ssize_t
2502 offset_show(mdk_rdev_t *rdev, char *page)
2503 {
2504 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2505 }
2506 
2507 static ssize_t
2508 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2509 {
2510 	char *e;
2511 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2512 	if (e==buf || (*e && *e != '\n'))
2513 		return -EINVAL;
2514 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2515 		return -EBUSY;
2516 	if (rdev->sectors && rdev->mddev->external)
2517 		/* Must set offset before size, so overlap checks
2518 		 * can be sane */
2519 		return -EBUSY;
2520 	rdev->data_offset = offset;
2521 	return len;
2522 }
2523 
2524 static struct rdev_sysfs_entry rdev_offset =
2525 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2526 
2527 static ssize_t
2528 rdev_size_show(mdk_rdev_t *rdev, char *page)
2529 {
2530 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2531 }
2532 
2533 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2534 {
2535 	/* check if two start/length pairs overlap */
2536 	if (s1+l1 <= s2)
2537 		return 0;
2538 	if (s2+l2 <= s1)
2539 		return 0;
2540 	return 1;
2541 }
2542 
2543 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2544 {
2545 	unsigned long long blocks;
2546 	sector_t new;
2547 
2548 	if (strict_strtoull(buf, 10, &blocks) < 0)
2549 		return -EINVAL;
2550 
2551 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2552 		return -EINVAL; /* sector conversion overflow */
2553 
2554 	new = blocks * 2;
2555 	if (new != blocks * 2)
2556 		return -EINVAL; /* unsigned long long to sector_t overflow */
2557 
2558 	*sectors = new;
2559 	return 0;
2560 }
2561 
2562 static ssize_t
2563 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2564 {
2565 	mddev_t *my_mddev = rdev->mddev;
2566 	sector_t oldsectors = rdev->sectors;
2567 	sector_t sectors;
2568 
2569 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2570 		return -EINVAL;
2571 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2572 		if (my_mddev->persistent) {
2573 			sectors = super_types[my_mddev->major_version].
2574 				rdev_size_change(rdev, sectors);
2575 			if (!sectors)
2576 				return -EBUSY;
2577 		} else if (!sectors)
2578 			sectors = (rdev->bdev->bd_inode->i_size >> 9) -
2579 				rdev->data_offset;
2580 	}
2581 	if (sectors < my_mddev->dev_sectors)
2582 		return -EINVAL; /* component must fit device */
2583 
2584 	rdev->sectors = sectors;
2585 	if (sectors > oldsectors && my_mddev->external) {
2586 		/* need to check that all other rdevs with the same ->bdev
2587 		 * do not overlap.  We need to unlock the mddev to avoid
2588 		 * a deadlock.  We have already changed rdev->sectors, and if
2589 		 * we have to change it back, we will have the lock again.
2590 		 */
2591 		mddev_t *mddev;
2592 		int overlap = 0;
2593 		struct list_head *tmp;
2594 
2595 		mddev_unlock(my_mddev);
2596 		for_each_mddev(mddev, tmp) {
2597 			mdk_rdev_t *rdev2;
2598 
2599 			mddev_lock(mddev);
2600 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2601 				if (test_bit(AllReserved, &rdev2->flags) ||
2602 				    (rdev->bdev == rdev2->bdev &&
2603 				     rdev != rdev2 &&
2604 				     overlaps(rdev->data_offset, rdev->sectors,
2605 					      rdev2->data_offset,
2606 					      rdev2->sectors))) {
2607 					overlap = 1;
2608 					break;
2609 				}
2610 			mddev_unlock(mddev);
2611 			if (overlap) {
2612 				mddev_put(mddev);
2613 				break;
2614 			}
2615 		}
2616 		mddev_lock(my_mddev);
2617 		if (overlap) {
2618 			/* Someone else could have slipped in a size
2619 			 * change here, but doing so is just silly.
2620 			 * We put oldsectors back because we *know* it is
2621 			 * safe, and trust userspace not to race with
2622 			 * itself
2623 			 */
2624 			rdev->sectors = oldsectors;
2625 			return -EBUSY;
2626 		}
2627 	}
2628 	return len;
2629 }
2630 
2631 static struct rdev_sysfs_entry rdev_size =
2632 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2633 
2634 
2635 static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
2636 {
2637 	unsigned long long recovery_start = rdev->recovery_offset;
2638 
2639 	if (test_bit(In_sync, &rdev->flags) ||
2640 	    recovery_start == MaxSector)
2641 		return sprintf(page, "none\n");
2642 
2643 	return sprintf(page, "%llu\n", recovery_start);
2644 }
2645 
2646 static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2647 {
2648 	unsigned long long recovery_start;
2649 
2650 	if (cmd_match(buf, "none"))
2651 		recovery_start = MaxSector;
2652 	else if (strict_strtoull(buf, 10, &recovery_start))
2653 		return -EINVAL;
2654 
2655 	if (rdev->mddev->pers &&
2656 	    rdev->raid_disk >= 0)
2657 		return -EBUSY;
2658 
2659 	rdev->recovery_offset = recovery_start;
2660 	if (recovery_start == MaxSector)
2661 		set_bit(In_sync, &rdev->flags);
2662 	else
2663 		clear_bit(In_sync, &rdev->flags);
2664 	return len;
2665 }
2666 
2667 static struct rdev_sysfs_entry rdev_recovery_start =
2668 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
2669 
2670 static struct attribute *rdev_default_attrs[] = {
2671 	&rdev_state.attr,
2672 	&rdev_errors.attr,
2673 	&rdev_slot.attr,
2674 	&rdev_offset.attr,
2675 	&rdev_size.attr,
2676 	&rdev_recovery_start.attr,
2677 	NULL,
2678 };
2679 static ssize_t
2680 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2681 {
2682 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2683 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2684 	mddev_t *mddev = rdev->mddev;
2685 	ssize_t rv;
2686 
2687 	if (!entry->show)
2688 		return -EIO;
2689 
2690 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2691 	if (!rv) {
2692 		if (rdev->mddev == NULL)
2693 			rv = -EBUSY;
2694 		else
2695 			rv = entry->show(rdev, page);
2696 		mddev_unlock(mddev);
2697 	}
2698 	return rv;
2699 }
2700 
2701 static ssize_t
2702 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2703 	      const char *page, size_t length)
2704 {
2705 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2706 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2707 	ssize_t rv;
2708 	mddev_t *mddev = rdev->mddev;
2709 
2710 	if (!entry->store)
2711 		return -EIO;
2712 	if (!capable(CAP_SYS_ADMIN))
2713 		return -EACCES;
2714 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2715 	if (!rv) {
2716 		if (rdev->mddev == NULL)
2717 			rv = -EBUSY;
2718 		else
2719 			rv = entry->store(rdev, page, length);
2720 		mddev_unlock(mddev);
2721 	}
2722 	return rv;
2723 }
2724 
2725 static void rdev_free(struct kobject *ko)
2726 {
2727 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2728 	kfree(rdev);
2729 }
2730 static const struct sysfs_ops rdev_sysfs_ops = {
2731 	.show		= rdev_attr_show,
2732 	.store		= rdev_attr_store,
2733 };
2734 static struct kobj_type rdev_ktype = {
2735 	.release	= rdev_free,
2736 	.sysfs_ops	= &rdev_sysfs_ops,
2737 	.default_attrs	= rdev_default_attrs,
2738 };
2739 
2740 void md_rdev_init(mdk_rdev_t *rdev)
2741 {
2742 	rdev->desc_nr = -1;
2743 	rdev->saved_raid_disk = -1;
2744 	rdev->raid_disk = -1;
2745 	rdev->flags = 0;
2746 	rdev->data_offset = 0;
2747 	rdev->sb_events = 0;
2748 	rdev->last_read_error.tv_sec  = 0;
2749 	rdev->last_read_error.tv_nsec = 0;
2750 	atomic_set(&rdev->nr_pending, 0);
2751 	atomic_set(&rdev->read_errors, 0);
2752 	atomic_set(&rdev->corrected_errors, 0);
2753 
2754 	INIT_LIST_HEAD(&rdev->same_set);
2755 	init_waitqueue_head(&rdev->blocked_wait);
2756 }
2757 EXPORT_SYMBOL_GPL(md_rdev_init);
2758 /*
2759  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2760  *
2761  * mark the device faulty if:
2762  *
2763  *   - the device is nonexistent (zero size)
2764  *   - the device has no valid superblock
2765  *
2766  * a faulty rdev _never_ has rdev->sb set.
2767  */
2768 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2769 {
2770 	char b[BDEVNAME_SIZE];
2771 	int err;
2772 	mdk_rdev_t *rdev;
2773 	sector_t size;
2774 
2775 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2776 	if (!rdev) {
2777 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2778 		return ERR_PTR(-ENOMEM);
2779 	}
2780 
2781 	md_rdev_init(rdev);
2782 	if ((err = alloc_disk_sb(rdev)))
2783 		goto abort_free;
2784 
2785 	err = lock_rdev(rdev, newdev, super_format == -2);
2786 	if (err)
2787 		goto abort_free;
2788 
2789 	kobject_init(&rdev->kobj, &rdev_ktype);
2790 
2791 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2792 	if (!size) {
2793 		printk(KERN_WARNING
2794 			"md: %s has zero or unknown size, marking faulty!\n",
2795 			bdevname(rdev->bdev,b));
2796 		err = -EINVAL;
2797 		goto abort_free;
2798 	}
2799 
2800 	if (super_format >= 0) {
2801 		err = super_types[super_format].
2802 			load_super(rdev, NULL, super_minor);
2803 		if (err == -EINVAL) {
2804 			printk(KERN_WARNING
2805 				"md: %s does not have a valid v%d.%d "
2806 			       "superblock, not importing!\n",
2807 				bdevname(rdev->bdev,b),
2808 			       super_format, super_minor);
2809 			goto abort_free;
2810 		}
2811 		if (err < 0) {
2812 			printk(KERN_WARNING
2813 				"md: could not read %s's sb, not importing!\n",
2814 				bdevname(rdev->bdev,b));
2815 			goto abort_free;
2816 		}
2817 	}
2818 
2819 	return rdev;
2820 
2821 abort_free:
2822 	if (rdev->sb_page) {
2823 		if (rdev->bdev)
2824 			unlock_rdev(rdev);
2825 		free_disk_sb(rdev);
2826 	}
2827 	kfree(rdev);
2828 	return ERR_PTR(err);
2829 }
2830 
2831 /*
2832  * Check a full RAID array for plausibility
2833  */
2834 
2835 
2836 static void analyze_sbs(mddev_t * mddev)
2837 {
2838 	int i;
2839 	mdk_rdev_t *rdev, *freshest, *tmp;
2840 	char b[BDEVNAME_SIZE];
2841 
2842 	freshest = NULL;
2843 	rdev_for_each(rdev, tmp, mddev)
2844 		switch (super_types[mddev->major_version].
2845 			load_super(rdev, freshest, mddev->minor_version)) {
2846 		case 1:
2847 			freshest = rdev;
2848 			break;
2849 		case 0:
2850 			break;
2851 		default:
2852 			printk( KERN_ERR \
2853 				"md: fatal superblock inconsistency in %s"
2854 				" -- removing from array\n",
2855 				bdevname(rdev->bdev,b));
2856 			kick_rdev_from_array(rdev);
2857 		}
2858 
2859 
2860 	super_types[mddev->major_version].
2861 		validate_super(mddev, freshest);
2862 
2863 	i = 0;
2864 	rdev_for_each(rdev, tmp, mddev) {
2865 		if (mddev->max_disks &&
2866 		    (rdev->desc_nr >= mddev->max_disks ||
2867 		     i > mddev->max_disks)) {
2868 			printk(KERN_WARNING
2869 			       "md: %s: %s: only %d devices permitted\n",
2870 			       mdname(mddev), bdevname(rdev->bdev, b),
2871 			       mddev->max_disks);
2872 			kick_rdev_from_array(rdev);
2873 			continue;
2874 		}
2875 		if (rdev != freshest)
2876 			if (super_types[mddev->major_version].
2877 			    validate_super(mddev, rdev)) {
2878 				printk(KERN_WARNING "md: kicking non-fresh %s"
2879 					" from array!\n",
2880 					bdevname(rdev->bdev,b));
2881 				kick_rdev_from_array(rdev);
2882 				continue;
2883 			}
2884 		if (mddev->level == LEVEL_MULTIPATH) {
2885 			rdev->desc_nr = i++;
2886 			rdev->raid_disk = rdev->desc_nr;
2887 			set_bit(In_sync, &rdev->flags);
2888 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
2889 			rdev->raid_disk = -1;
2890 			clear_bit(In_sync, &rdev->flags);
2891 		}
2892 	}
2893 }
2894 
2895 /* Read a fixed-point number.
2896  * Numbers in sysfs attributes should be in "standard" units where
2897  * possible, so time should be in seconds.
2898  * However we internally use a a much smaller unit such as
2899  * milliseconds or jiffies.
2900  * This function takes a decimal number with a possible fractional
2901  * component, and produces an integer which is the result of
2902  * multiplying that number by 10^'scale'.
2903  * all without any floating-point arithmetic.
2904  */
2905 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
2906 {
2907 	unsigned long result = 0;
2908 	long decimals = -1;
2909 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
2910 		if (*cp == '.')
2911 			decimals = 0;
2912 		else if (decimals < scale) {
2913 			unsigned int value;
2914 			value = *cp - '0';
2915 			result = result * 10 + value;
2916 			if (decimals >= 0)
2917 				decimals++;
2918 		}
2919 		cp++;
2920 	}
2921 	if (*cp == '\n')
2922 		cp++;
2923 	if (*cp)
2924 		return -EINVAL;
2925 	if (decimals < 0)
2926 		decimals = 0;
2927 	while (decimals < scale) {
2928 		result *= 10;
2929 		decimals ++;
2930 	}
2931 	*res = result;
2932 	return 0;
2933 }
2934 
2935 
2936 static void md_safemode_timeout(unsigned long data);
2937 
2938 static ssize_t
2939 safe_delay_show(mddev_t *mddev, char *page)
2940 {
2941 	int msec = (mddev->safemode_delay*1000)/HZ;
2942 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2943 }
2944 static ssize_t
2945 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2946 {
2947 	unsigned long msec;
2948 
2949 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
2950 		return -EINVAL;
2951 	if (msec == 0)
2952 		mddev->safemode_delay = 0;
2953 	else {
2954 		unsigned long old_delay = mddev->safemode_delay;
2955 		mddev->safemode_delay = (msec*HZ)/1000;
2956 		if (mddev->safemode_delay == 0)
2957 			mddev->safemode_delay = 1;
2958 		if (mddev->safemode_delay < old_delay)
2959 			md_safemode_timeout((unsigned long)mddev);
2960 	}
2961 	return len;
2962 }
2963 static struct md_sysfs_entry md_safe_delay =
2964 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2965 
2966 static ssize_t
2967 level_show(mddev_t *mddev, char *page)
2968 {
2969 	struct mdk_personality *p = mddev->pers;
2970 	if (p)
2971 		return sprintf(page, "%s\n", p->name);
2972 	else if (mddev->clevel[0])
2973 		return sprintf(page, "%s\n", mddev->clevel);
2974 	else if (mddev->level != LEVEL_NONE)
2975 		return sprintf(page, "%d\n", mddev->level);
2976 	else
2977 		return 0;
2978 }
2979 
2980 static ssize_t
2981 level_store(mddev_t *mddev, const char *buf, size_t len)
2982 {
2983 	char clevel[16];
2984 	ssize_t rv = len;
2985 	struct mdk_personality *pers;
2986 	long level;
2987 	void *priv;
2988 	mdk_rdev_t *rdev;
2989 
2990 	if (mddev->pers == NULL) {
2991 		if (len == 0)
2992 			return 0;
2993 		if (len >= sizeof(mddev->clevel))
2994 			return -ENOSPC;
2995 		strncpy(mddev->clevel, buf, len);
2996 		if (mddev->clevel[len-1] == '\n')
2997 			len--;
2998 		mddev->clevel[len] = 0;
2999 		mddev->level = LEVEL_NONE;
3000 		return rv;
3001 	}
3002 
3003 	/* request to change the personality.  Need to ensure:
3004 	 *  - array is not engaged in resync/recovery/reshape
3005 	 *  - old personality can be suspended
3006 	 *  - new personality will access other array.
3007 	 */
3008 
3009 	if (mddev->sync_thread ||
3010 	    mddev->reshape_position != MaxSector ||
3011 	    mddev->sysfs_active)
3012 		return -EBUSY;
3013 
3014 	if (!mddev->pers->quiesce) {
3015 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3016 		       mdname(mddev), mddev->pers->name);
3017 		return -EINVAL;
3018 	}
3019 
3020 	/* Now find the new personality */
3021 	if (len == 0 || len >= sizeof(clevel))
3022 		return -EINVAL;
3023 	strncpy(clevel, buf, len);
3024 	if (clevel[len-1] == '\n')
3025 		len--;
3026 	clevel[len] = 0;
3027 	if (strict_strtol(clevel, 10, &level))
3028 		level = LEVEL_NONE;
3029 
3030 	if (request_module("md-%s", clevel) != 0)
3031 		request_module("md-level-%s", clevel);
3032 	spin_lock(&pers_lock);
3033 	pers = find_pers(level, clevel);
3034 	if (!pers || !try_module_get(pers->owner)) {
3035 		spin_unlock(&pers_lock);
3036 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3037 		return -EINVAL;
3038 	}
3039 	spin_unlock(&pers_lock);
3040 
3041 	if (pers == mddev->pers) {
3042 		/* Nothing to do! */
3043 		module_put(pers->owner);
3044 		return rv;
3045 	}
3046 	if (!pers->takeover) {
3047 		module_put(pers->owner);
3048 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3049 		       mdname(mddev), clevel);
3050 		return -EINVAL;
3051 	}
3052 
3053 	list_for_each_entry(rdev, &mddev->disks, same_set)
3054 		rdev->new_raid_disk = rdev->raid_disk;
3055 
3056 	/* ->takeover must set new_* and/or delta_disks
3057 	 * if it succeeds, and may set them when it fails.
3058 	 */
3059 	priv = pers->takeover(mddev);
3060 	if (IS_ERR(priv)) {
3061 		mddev->new_level = mddev->level;
3062 		mddev->new_layout = mddev->layout;
3063 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3064 		mddev->raid_disks -= mddev->delta_disks;
3065 		mddev->delta_disks = 0;
3066 		module_put(pers->owner);
3067 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3068 		       mdname(mddev), clevel);
3069 		return PTR_ERR(priv);
3070 	}
3071 
3072 	/* Looks like we have a winner */
3073 	mddev_suspend(mddev);
3074 	mddev->pers->stop(mddev);
3075 
3076 	if (mddev->pers->sync_request == NULL &&
3077 	    pers->sync_request != NULL) {
3078 		/* need to add the md_redundancy_group */
3079 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3080 			printk(KERN_WARNING
3081 			       "md: cannot register extra attributes for %s\n",
3082 			       mdname(mddev));
3083 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3084 	}
3085 	if (mddev->pers->sync_request != NULL &&
3086 	    pers->sync_request == NULL) {
3087 		/* need to remove the md_redundancy_group */
3088 		if (mddev->to_remove == NULL)
3089 			mddev->to_remove = &md_redundancy_group;
3090 	}
3091 
3092 	if (mddev->pers->sync_request == NULL &&
3093 	    mddev->external) {
3094 		/* We are converting from a no-redundancy array
3095 		 * to a redundancy array and metadata is managed
3096 		 * externally so we need to be sure that writes
3097 		 * won't block due to a need to transition
3098 		 *      clean->dirty
3099 		 * until external management is started.
3100 		 */
3101 		mddev->in_sync = 0;
3102 		mddev->safemode_delay = 0;
3103 		mddev->safemode = 0;
3104 	}
3105 
3106 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3107 		char nm[20];
3108 		if (rdev->raid_disk < 0)
3109 			continue;
3110 		if (rdev->new_raid_disk > mddev->raid_disks)
3111 			rdev->new_raid_disk = -1;
3112 		if (rdev->new_raid_disk == rdev->raid_disk)
3113 			continue;
3114 		sprintf(nm, "rd%d", rdev->raid_disk);
3115 		sysfs_remove_link(&mddev->kobj, nm);
3116 	}
3117 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3118 		if (rdev->raid_disk < 0)
3119 			continue;
3120 		if (rdev->new_raid_disk == rdev->raid_disk)
3121 			continue;
3122 		rdev->raid_disk = rdev->new_raid_disk;
3123 		if (rdev->raid_disk < 0)
3124 			clear_bit(In_sync, &rdev->flags);
3125 		else {
3126 			char nm[20];
3127 			sprintf(nm, "rd%d", rdev->raid_disk);
3128 			if(sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
3129 				printk("md: cannot register %s for %s after level change\n",
3130 				       nm, mdname(mddev));
3131 		}
3132 	}
3133 
3134 	module_put(mddev->pers->owner);
3135 	mddev->pers = pers;
3136 	mddev->private = priv;
3137 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3138 	mddev->level = mddev->new_level;
3139 	mddev->layout = mddev->new_layout;
3140 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3141 	mddev->delta_disks = 0;
3142 	if (mddev->pers->sync_request == NULL) {
3143 		/* this is now an array without redundancy, so
3144 		 * it must always be in_sync
3145 		 */
3146 		mddev->in_sync = 1;
3147 		del_timer_sync(&mddev->safemode_timer);
3148 	}
3149 	pers->run(mddev);
3150 	mddev_resume(mddev);
3151 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3152 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3153 	md_wakeup_thread(mddev->thread);
3154 	sysfs_notify(&mddev->kobj, NULL, "level");
3155 	md_new_event(mddev);
3156 	return rv;
3157 }
3158 
3159 static struct md_sysfs_entry md_level =
3160 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3161 
3162 
3163 static ssize_t
3164 layout_show(mddev_t *mddev, char *page)
3165 {
3166 	/* just a number, not meaningful for all levels */
3167 	if (mddev->reshape_position != MaxSector &&
3168 	    mddev->layout != mddev->new_layout)
3169 		return sprintf(page, "%d (%d)\n",
3170 			       mddev->new_layout, mddev->layout);
3171 	return sprintf(page, "%d\n", mddev->layout);
3172 }
3173 
3174 static ssize_t
3175 layout_store(mddev_t *mddev, const char *buf, size_t len)
3176 {
3177 	char *e;
3178 	unsigned long n = simple_strtoul(buf, &e, 10);
3179 
3180 	if (!*buf || (*e && *e != '\n'))
3181 		return -EINVAL;
3182 
3183 	if (mddev->pers) {
3184 		int err;
3185 		if (mddev->pers->check_reshape == NULL)
3186 			return -EBUSY;
3187 		mddev->new_layout = n;
3188 		err = mddev->pers->check_reshape(mddev);
3189 		if (err) {
3190 			mddev->new_layout = mddev->layout;
3191 			return err;
3192 		}
3193 	} else {
3194 		mddev->new_layout = n;
3195 		if (mddev->reshape_position == MaxSector)
3196 			mddev->layout = n;
3197 	}
3198 	return len;
3199 }
3200 static struct md_sysfs_entry md_layout =
3201 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3202 
3203 
3204 static ssize_t
3205 raid_disks_show(mddev_t *mddev, char *page)
3206 {
3207 	if (mddev->raid_disks == 0)
3208 		return 0;
3209 	if (mddev->reshape_position != MaxSector &&
3210 	    mddev->delta_disks != 0)
3211 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3212 			       mddev->raid_disks - mddev->delta_disks);
3213 	return sprintf(page, "%d\n", mddev->raid_disks);
3214 }
3215 
3216 static int update_raid_disks(mddev_t *mddev, int raid_disks);
3217 
3218 static ssize_t
3219 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
3220 {
3221 	char *e;
3222 	int rv = 0;
3223 	unsigned long n = simple_strtoul(buf, &e, 10);
3224 
3225 	if (!*buf || (*e && *e != '\n'))
3226 		return -EINVAL;
3227 
3228 	if (mddev->pers)
3229 		rv = update_raid_disks(mddev, n);
3230 	else if (mddev->reshape_position != MaxSector) {
3231 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3232 		mddev->delta_disks = n - olddisks;
3233 		mddev->raid_disks = n;
3234 	} else
3235 		mddev->raid_disks = n;
3236 	return rv ? rv : len;
3237 }
3238 static struct md_sysfs_entry md_raid_disks =
3239 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3240 
3241 static ssize_t
3242 chunk_size_show(mddev_t *mddev, char *page)
3243 {
3244 	if (mddev->reshape_position != MaxSector &&
3245 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3246 		return sprintf(page, "%d (%d)\n",
3247 			       mddev->new_chunk_sectors << 9,
3248 			       mddev->chunk_sectors << 9);
3249 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3250 }
3251 
3252 static ssize_t
3253 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
3254 {
3255 	char *e;
3256 	unsigned long n = simple_strtoul(buf, &e, 10);
3257 
3258 	if (!*buf || (*e && *e != '\n'))
3259 		return -EINVAL;
3260 
3261 	if (mddev->pers) {
3262 		int err;
3263 		if (mddev->pers->check_reshape == NULL)
3264 			return -EBUSY;
3265 		mddev->new_chunk_sectors = n >> 9;
3266 		err = mddev->pers->check_reshape(mddev);
3267 		if (err) {
3268 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3269 			return err;
3270 		}
3271 	} else {
3272 		mddev->new_chunk_sectors = n >> 9;
3273 		if (mddev->reshape_position == MaxSector)
3274 			mddev->chunk_sectors = n >> 9;
3275 	}
3276 	return len;
3277 }
3278 static struct md_sysfs_entry md_chunk_size =
3279 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3280 
3281 static ssize_t
3282 resync_start_show(mddev_t *mddev, char *page)
3283 {
3284 	if (mddev->recovery_cp == MaxSector)
3285 		return sprintf(page, "none\n");
3286 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3287 }
3288 
3289 static ssize_t
3290 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
3291 {
3292 	char *e;
3293 	unsigned long long n = simple_strtoull(buf, &e, 10);
3294 
3295 	if (mddev->pers)
3296 		return -EBUSY;
3297 	if (cmd_match(buf, "none"))
3298 		n = MaxSector;
3299 	else if (!*buf || (*e && *e != '\n'))
3300 		return -EINVAL;
3301 
3302 	mddev->recovery_cp = n;
3303 	return len;
3304 }
3305 static struct md_sysfs_entry md_resync_start =
3306 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3307 
3308 /*
3309  * The array state can be:
3310  *
3311  * clear
3312  *     No devices, no size, no level
3313  *     Equivalent to STOP_ARRAY ioctl
3314  * inactive
3315  *     May have some settings, but array is not active
3316  *        all IO results in error
3317  *     When written, doesn't tear down array, but just stops it
3318  * suspended (not supported yet)
3319  *     All IO requests will block. The array can be reconfigured.
3320  *     Writing this, if accepted, will block until array is quiescent
3321  * readonly
3322  *     no resync can happen.  no superblocks get written.
3323  *     write requests fail
3324  * read-auto
3325  *     like readonly, but behaves like 'clean' on a write request.
3326  *
3327  * clean - no pending writes, but otherwise active.
3328  *     When written to inactive array, starts without resync
3329  *     If a write request arrives then
3330  *       if metadata is known, mark 'dirty' and switch to 'active'.
3331  *       if not known, block and switch to write-pending
3332  *     If written to an active array that has pending writes, then fails.
3333  * active
3334  *     fully active: IO and resync can be happening.
3335  *     When written to inactive array, starts with resync
3336  *
3337  * write-pending
3338  *     clean, but writes are blocked waiting for 'active' to be written.
3339  *
3340  * active-idle
3341  *     like active, but no writes have been seen for a while (100msec).
3342  *
3343  */
3344 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3345 		   write_pending, active_idle, bad_word};
3346 static char *array_states[] = {
3347 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3348 	"write-pending", "active-idle", NULL };
3349 
3350 static int match_word(const char *word, char **list)
3351 {
3352 	int n;
3353 	for (n=0; list[n]; n++)
3354 		if (cmd_match(word, list[n]))
3355 			break;
3356 	return n;
3357 }
3358 
3359 static ssize_t
3360 array_state_show(mddev_t *mddev, char *page)
3361 {
3362 	enum array_state st = inactive;
3363 
3364 	if (mddev->pers)
3365 		switch(mddev->ro) {
3366 		case 1:
3367 			st = readonly;
3368 			break;
3369 		case 2:
3370 			st = read_auto;
3371 			break;
3372 		case 0:
3373 			if (mddev->in_sync)
3374 				st = clean;
3375 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3376 				st = write_pending;
3377 			else if (mddev->safemode)
3378 				st = active_idle;
3379 			else
3380 				st = active;
3381 		}
3382 	else {
3383 		if (list_empty(&mddev->disks) &&
3384 		    mddev->raid_disks == 0 &&
3385 		    mddev->dev_sectors == 0)
3386 			st = clear;
3387 		else
3388 			st = inactive;
3389 	}
3390 	return sprintf(page, "%s\n", array_states[st]);
3391 }
3392 
3393 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3394 static int md_set_readonly(mddev_t * mddev, int is_open);
3395 static int do_md_run(mddev_t * mddev);
3396 static int restart_array(mddev_t *mddev);
3397 
3398 static ssize_t
3399 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3400 {
3401 	int err = -EINVAL;
3402 	enum array_state st = match_word(buf, array_states);
3403 	switch(st) {
3404 	case bad_word:
3405 		break;
3406 	case clear:
3407 		/* stopping an active array */
3408 		if (atomic_read(&mddev->openers) > 0)
3409 			return -EBUSY;
3410 		err = do_md_stop(mddev, 0, 0);
3411 		break;
3412 	case inactive:
3413 		/* stopping an active array */
3414 		if (mddev->pers) {
3415 			if (atomic_read(&mddev->openers) > 0)
3416 				return -EBUSY;
3417 			err = do_md_stop(mddev, 2, 0);
3418 		} else
3419 			err = 0; /* already inactive */
3420 		break;
3421 	case suspended:
3422 		break; /* not supported yet */
3423 	case readonly:
3424 		if (mddev->pers)
3425 			err = md_set_readonly(mddev, 0);
3426 		else {
3427 			mddev->ro = 1;
3428 			set_disk_ro(mddev->gendisk, 1);
3429 			err = do_md_run(mddev);
3430 		}
3431 		break;
3432 	case read_auto:
3433 		if (mddev->pers) {
3434 			if (mddev->ro == 0)
3435 				err = md_set_readonly(mddev, 0);
3436 			else if (mddev->ro == 1)
3437 				err = restart_array(mddev);
3438 			if (err == 0) {
3439 				mddev->ro = 2;
3440 				set_disk_ro(mddev->gendisk, 0);
3441 			}
3442 		} else {
3443 			mddev->ro = 2;
3444 			err = do_md_run(mddev);
3445 		}
3446 		break;
3447 	case clean:
3448 		if (mddev->pers) {
3449 			restart_array(mddev);
3450 			spin_lock_irq(&mddev->write_lock);
3451 			if (atomic_read(&mddev->writes_pending) == 0) {
3452 				if (mddev->in_sync == 0) {
3453 					mddev->in_sync = 1;
3454 					if (mddev->safemode == 1)
3455 						mddev->safemode = 0;
3456 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3457 				}
3458 				err = 0;
3459 			} else
3460 				err = -EBUSY;
3461 			spin_unlock_irq(&mddev->write_lock);
3462 		} else
3463 			err = -EINVAL;
3464 		break;
3465 	case active:
3466 		if (mddev->pers) {
3467 			restart_array(mddev);
3468 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3469 			wake_up(&mddev->sb_wait);
3470 			err = 0;
3471 		} else {
3472 			mddev->ro = 0;
3473 			set_disk_ro(mddev->gendisk, 0);
3474 			err = do_md_run(mddev);
3475 		}
3476 		break;
3477 	case write_pending:
3478 	case active_idle:
3479 		/* these cannot be set */
3480 		break;
3481 	}
3482 	if (err)
3483 		return err;
3484 	else {
3485 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3486 		return len;
3487 	}
3488 }
3489 static struct md_sysfs_entry md_array_state =
3490 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3491 
3492 static ssize_t
3493 max_corrected_read_errors_show(mddev_t *mddev, char *page) {
3494 	return sprintf(page, "%d\n",
3495 		       atomic_read(&mddev->max_corr_read_errors));
3496 }
3497 
3498 static ssize_t
3499 max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
3500 {
3501 	char *e;
3502 	unsigned long n = simple_strtoul(buf, &e, 10);
3503 
3504 	if (*buf && (*e == 0 || *e == '\n')) {
3505 		atomic_set(&mddev->max_corr_read_errors, n);
3506 		return len;
3507 	}
3508 	return -EINVAL;
3509 }
3510 
3511 static struct md_sysfs_entry max_corr_read_errors =
3512 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3513 	max_corrected_read_errors_store);
3514 
3515 static ssize_t
3516 null_show(mddev_t *mddev, char *page)
3517 {
3518 	return -EINVAL;
3519 }
3520 
3521 static ssize_t
3522 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3523 {
3524 	/* buf must be %d:%d\n? giving major and minor numbers */
3525 	/* The new device is added to the array.
3526 	 * If the array has a persistent superblock, we read the
3527 	 * superblock to initialise info and check validity.
3528 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3529 	 * which mainly checks size.
3530 	 */
3531 	char *e;
3532 	int major = simple_strtoul(buf, &e, 10);
3533 	int minor;
3534 	dev_t dev;
3535 	mdk_rdev_t *rdev;
3536 	int err;
3537 
3538 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3539 		return -EINVAL;
3540 	minor = simple_strtoul(e+1, &e, 10);
3541 	if (*e && *e != '\n')
3542 		return -EINVAL;
3543 	dev = MKDEV(major, minor);
3544 	if (major != MAJOR(dev) ||
3545 	    minor != MINOR(dev))
3546 		return -EOVERFLOW;
3547 
3548 
3549 	if (mddev->persistent) {
3550 		rdev = md_import_device(dev, mddev->major_version,
3551 					mddev->minor_version);
3552 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3553 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3554 						       mdk_rdev_t, same_set);
3555 			err = super_types[mddev->major_version]
3556 				.load_super(rdev, rdev0, mddev->minor_version);
3557 			if (err < 0)
3558 				goto out;
3559 		}
3560 	} else if (mddev->external)
3561 		rdev = md_import_device(dev, -2, -1);
3562 	else
3563 		rdev = md_import_device(dev, -1, -1);
3564 
3565 	if (IS_ERR(rdev))
3566 		return PTR_ERR(rdev);
3567 	err = bind_rdev_to_array(rdev, mddev);
3568  out:
3569 	if (err)
3570 		export_rdev(rdev);
3571 	return err ? err : len;
3572 }
3573 
3574 static struct md_sysfs_entry md_new_device =
3575 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3576 
3577 static ssize_t
3578 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3579 {
3580 	char *end;
3581 	unsigned long chunk, end_chunk;
3582 
3583 	if (!mddev->bitmap)
3584 		goto out;
3585 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3586 	while (*buf) {
3587 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3588 		if (buf == end) break;
3589 		if (*end == '-') { /* range */
3590 			buf = end + 1;
3591 			end_chunk = simple_strtoul(buf, &end, 0);
3592 			if (buf == end) break;
3593 		}
3594 		if (*end && !isspace(*end)) break;
3595 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3596 		buf = skip_spaces(end);
3597 	}
3598 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3599 out:
3600 	return len;
3601 }
3602 
3603 static struct md_sysfs_entry md_bitmap =
3604 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3605 
3606 static ssize_t
3607 size_show(mddev_t *mddev, char *page)
3608 {
3609 	return sprintf(page, "%llu\n",
3610 		(unsigned long long)mddev->dev_sectors / 2);
3611 }
3612 
3613 static int update_size(mddev_t *mddev, sector_t num_sectors);
3614 
3615 static ssize_t
3616 size_store(mddev_t *mddev, const char *buf, size_t len)
3617 {
3618 	/* If array is inactive, we can reduce the component size, but
3619 	 * not increase it (except from 0).
3620 	 * If array is active, we can try an on-line resize
3621 	 */
3622 	sector_t sectors;
3623 	int err = strict_blocks_to_sectors(buf, &sectors);
3624 
3625 	if (err < 0)
3626 		return err;
3627 	if (mddev->pers) {
3628 		err = update_size(mddev, sectors);
3629 		md_update_sb(mddev, 1);
3630 	} else {
3631 		if (mddev->dev_sectors == 0 ||
3632 		    mddev->dev_sectors > sectors)
3633 			mddev->dev_sectors = sectors;
3634 		else
3635 			err = -ENOSPC;
3636 	}
3637 	return err ? err : len;
3638 }
3639 
3640 static struct md_sysfs_entry md_size =
3641 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3642 
3643 
3644 /* Metdata version.
3645  * This is one of
3646  *   'none' for arrays with no metadata (good luck...)
3647  *   'external' for arrays with externally managed metadata,
3648  * or N.M for internally known formats
3649  */
3650 static ssize_t
3651 metadata_show(mddev_t *mddev, char *page)
3652 {
3653 	if (mddev->persistent)
3654 		return sprintf(page, "%d.%d\n",
3655 			       mddev->major_version, mddev->minor_version);
3656 	else if (mddev->external)
3657 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3658 	else
3659 		return sprintf(page, "none\n");
3660 }
3661 
3662 static ssize_t
3663 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3664 {
3665 	int major, minor;
3666 	char *e;
3667 	/* Changing the details of 'external' metadata is
3668 	 * always permitted.  Otherwise there must be
3669 	 * no devices attached to the array.
3670 	 */
3671 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3672 		;
3673 	else if (!list_empty(&mddev->disks))
3674 		return -EBUSY;
3675 
3676 	if (cmd_match(buf, "none")) {
3677 		mddev->persistent = 0;
3678 		mddev->external = 0;
3679 		mddev->major_version = 0;
3680 		mddev->minor_version = 90;
3681 		return len;
3682 	}
3683 	if (strncmp(buf, "external:", 9) == 0) {
3684 		size_t namelen = len-9;
3685 		if (namelen >= sizeof(mddev->metadata_type))
3686 			namelen = sizeof(mddev->metadata_type)-1;
3687 		strncpy(mddev->metadata_type, buf+9, namelen);
3688 		mddev->metadata_type[namelen] = 0;
3689 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3690 			mddev->metadata_type[--namelen] = 0;
3691 		mddev->persistent = 0;
3692 		mddev->external = 1;
3693 		mddev->major_version = 0;
3694 		mddev->minor_version = 90;
3695 		return len;
3696 	}
3697 	major = simple_strtoul(buf, &e, 10);
3698 	if (e==buf || *e != '.')
3699 		return -EINVAL;
3700 	buf = e+1;
3701 	minor = simple_strtoul(buf, &e, 10);
3702 	if (e==buf || (*e && *e != '\n') )
3703 		return -EINVAL;
3704 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3705 		return -ENOENT;
3706 	mddev->major_version = major;
3707 	mddev->minor_version = minor;
3708 	mddev->persistent = 1;
3709 	mddev->external = 0;
3710 	return len;
3711 }
3712 
3713 static struct md_sysfs_entry md_metadata =
3714 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3715 
3716 static ssize_t
3717 action_show(mddev_t *mddev, char *page)
3718 {
3719 	char *type = "idle";
3720 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3721 		type = "frozen";
3722 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3723 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3724 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3725 			type = "reshape";
3726 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3727 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3728 				type = "resync";
3729 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3730 				type = "check";
3731 			else
3732 				type = "repair";
3733 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3734 			type = "recover";
3735 	}
3736 	return sprintf(page, "%s\n", type);
3737 }
3738 
3739 static ssize_t
3740 action_store(mddev_t *mddev, const char *page, size_t len)
3741 {
3742 	if (!mddev->pers || !mddev->pers->sync_request)
3743 		return -EINVAL;
3744 
3745 	if (cmd_match(page, "frozen"))
3746 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3747 	else
3748 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3749 
3750 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
3751 		if (mddev->sync_thread) {
3752 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3753 			md_unregister_thread(mddev->sync_thread);
3754 			mddev->sync_thread = NULL;
3755 			mddev->recovery = 0;
3756 		}
3757 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3758 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3759 		return -EBUSY;
3760 	else if (cmd_match(page, "resync"))
3761 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3762 	else if (cmd_match(page, "recover")) {
3763 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3764 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3765 	} else if (cmd_match(page, "reshape")) {
3766 		int err;
3767 		if (mddev->pers->start_reshape == NULL)
3768 			return -EINVAL;
3769 		err = mddev->pers->start_reshape(mddev);
3770 		if (err)
3771 			return err;
3772 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3773 	} else {
3774 		if (cmd_match(page, "check"))
3775 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3776 		else if (!cmd_match(page, "repair"))
3777 			return -EINVAL;
3778 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3779 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3780 	}
3781 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3782 	md_wakeup_thread(mddev->thread);
3783 	sysfs_notify_dirent_safe(mddev->sysfs_action);
3784 	return len;
3785 }
3786 
3787 static ssize_t
3788 mismatch_cnt_show(mddev_t *mddev, char *page)
3789 {
3790 	return sprintf(page, "%llu\n",
3791 		       (unsigned long long) mddev->resync_mismatches);
3792 }
3793 
3794 static struct md_sysfs_entry md_scan_mode =
3795 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3796 
3797 
3798 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3799 
3800 static ssize_t
3801 sync_min_show(mddev_t *mddev, char *page)
3802 {
3803 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3804 		       mddev->sync_speed_min ? "local": "system");
3805 }
3806 
3807 static ssize_t
3808 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3809 {
3810 	int min;
3811 	char *e;
3812 	if (strncmp(buf, "system", 6)==0) {
3813 		mddev->sync_speed_min = 0;
3814 		return len;
3815 	}
3816 	min = simple_strtoul(buf, &e, 10);
3817 	if (buf == e || (*e && *e != '\n') || min <= 0)
3818 		return -EINVAL;
3819 	mddev->sync_speed_min = min;
3820 	return len;
3821 }
3822 
3823 static struct md_sysfs_entry md_sync_min =
3824 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3825 
3826 static ssize_t
3827 sync_max_show(mddev_t *mddev, char *page)
3828 {
3829 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3830 		       mddev->sync_speed_max ? "local": "system");
3831 }
3832 
3833 static ssize_t
3834 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3835 {
3836 	int max;
3837 	char *e;
3838 	if (strncmp(buf, "system", 6)==0) {
3839 		mddev->sync_speed_max = 0;
3840 		return len;
3841 	}
3842 	max = simple_strtoul(buf, &e, 10);
3843 	if (buf == e || (*e && *e != '\n') || max <= 0)
3844 		return -EINVAL;
3845 	mddev->sync_speed_max = max;
3846 	return len;
3847 }
3848 
3849 static struct md_sysfs_entry md_sync_max =
3850 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3851 
3852 static ssize_t
3853 degraded_show(mddev_t *mddev, char *page)
3854 {
3855 	return sprintf(page, "%d\n", mddev->degraded);
3856 }
3857 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3858 
3859 static ssize_t
3860 sync_force_parallel_show(mddev_t *mddev, char *page)
3861 {
3862 	return sprintf(page, "%d\n", mddev->parallel_resync);
3863 }
3864 
3865 static ssize_t
3866 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3867 {
3868 	long n;
3869 
3870 	if (strict_strtol(buf, 10, &n))
3871 		return -EINVAL;
3872 
3873 	if (n != 0 && n != 1)
3874 		return -EINVAL;
3875 
3876 	mddev->parallel_resync = n;
3877 
3878 	if (mddev->sync_thread)
3879 		wake_up(&resync_wait);
3880 
3881 	return len;
3882 }
3883 
3884 /* force parallel resync, even with shared block devices */
3885 static struct md_sysfs_entry md_sync_force_parallel =
3886 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3887        sync_force_parallel_show, sync_force_parallel_store);
3888 
3889 static ssize_t
3890 sync_speed_show(mddev_t *mddev, char *page)
3891 {
3892 	unsigned long resync, dt, db;
3893 	if (mddev->curr_resync == 0)
3894 		return sprintf(page, "none\n");
3895 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3896 	dt = (jiffies - mddev->resync_mark) / HZ;
3897 	if (!dt) dt++;
3898 	db = resync - mddev->resync_mark_cnt;
3899 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3900 }
3901 
3902 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3903 
3904 static ssize_t
3905 sync_completed_show(mddev_t *mddev, char *page)
3906 {
3907 	unsigned long max_sectors, resync;
3908 
3909 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3910 		return sprintf(page, "none\n");
3911 
3912 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3913 		max_sectors = mddev->resync_max_sectors;
3914 	else
3915 		max_sectors = mddev->dev_sectors;
3916 
3917 	resync = mddev->curr_resync_completed;
3918 	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
3919 }
3920 
3921 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3922 
3923 static ssize_t
3924 min_sync_show(mddev_t *mddev, char *page)
3925 {
3926 	return sprintf(page, "%llu\n",
3927 		       (unsigned long long)mddev->resync_min);
3928 }
3929 static ssize_t
3930 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3931 {
3932 	unsigned long long min;
3933 	if (strict_strtoull(buf, 10, &min))
3934 		return -EINVAL;
3935 	if (min > mddev->resync_max)
3936 		return -EINVAL;
3937 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3938 		return -EBUSY;
3939 
3940 	/* Must be a multiple of chunk_size */
3941 	if (mddev->chunk_sectors) {
3942 		sector_t temp = min;
3943 		if (sector_div(temp, mddev->chunk_sectors))
3944 			return -EINVAL;
3945 	}
3946 	mddev->resync_min = min;
3947 
3948 	return len;
3949 }
3950 
3951 static struct md_sysfs_entry md_min_sync =
3952 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3953 
3954 static ssize_t
3955 max_sync_show(mddev_t *mddev, char *page)
3956 {
3957 	if (mddev->resync_max == MaxSector)
3958 		return sprintf(page, "max\n");
3959 	else
3960 		return sprintf(page, "%llu\n",
3961 			       (unsigned long long)mddev->resync_max);
3962 }
3963 static ssize_t
3964 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3965 {
3966 	if (strncmp(buf, "max", 3) == 0)
3967 		mddev->resync_max = MaxSector;
3968 	else {
3969 		unsigned long long max;
3970 		if (strict_strtoull(buf, 10, &max))
3971 			return -EINVAL;
3972 		if (max < mddev->resync_min)
3973 			return -EINVAL;
3974 		if (max < mddev->resync_max &&
3975 		    mddev->ro == 0 &&
3976 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3977 			return -EBUSY;
3978 
3979 		/* Must be a multiple of chunk_size */
3980 		if (mddev->chunk_sectors) {
3981 			sector_t temp = max;
3982 			if (sector_div(temp, mddev->chunk_sectors))
3983 				return -EINVAL;
3984 		}
3985 		mddev->resync_max = max;
3986 	}
3987 	wake_up(&mddev->recovery_wait);
3988 	return len;
3989 }
3990 
3991 static struct md_sysfs_entry md_max_sync =
3992 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
3993 
3994 static ssize_t
3995 suspend_lo_show(mddev_t *mddev, char *page)
3996 {
3997 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
3998 }
3999 
4000 static ssize_t
4001 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
4002 {
4003 	char *e;
4004 	unsigned long long new = simple_strtoull(buf, &e, 10);
4005 
4006 	if (mddev->pers == NULL ||
4007 	    mddev->pers->quiesce == NULL)
4008 		return -EINVAL;
4009 	if (buf == e || (*e && *e != '\n'))
4010 		return -EINVAL;
4011 	if (new >= mddev->suspend_hi ||
4012 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
4013 		mddev->suspend_lo = new;
4014 		mddev->pers->quiesce(mddev, 2);
4015 		return len;
4016 	} else
4017 		return -EINVAL;
4018 }
4019 static struct md_sysfs_entry md_suspend_lo =
4020 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4021 
4022 
4023 static ssize_t
4024 suspend_hi_show(mddev_t *mddev, char *page)
4025 {
4026 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4027 }
4028 
4029 static ssize_t
4030 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
4031 {
4032 	char *e;
4033 	unsigned long long new = simple_strtoull(buf, &e, 10);
4034 
4035 	if (mddev->pers == NULL ||
4036 	    mddev->pers->quiesce == NULL)
4037 		return -EINVAL;
4038 	if (buf == e || (*e && *e != '\n'))
4039 		return -EINVAL;
4040 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
4041 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
4042 		mddev->suspend_hi = new;
4043 		mddev->pers->quiesce(mddev, 1);
4044 		mddev->pers->quiesce(mddev, 0);
4045 		return len;
4046 	} else
4047 		return -EINVAL;
4048 }
4049 static struct md_sysfs_entry md_suspend_hi =
4050 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4051 
4052 static ssize_t
4053 reshape_position_show(mddev_t *mddev, char *page)
4054 {
4055 	if (mddev->reshape_position != MaxSector)
4056 		return sprintf(page, "%llu\n",
4057 			       (unsigned long long)mddev->reshape_position);
4058 	strcpy(page, "none\n");
4059 	return 5;
4060 }
4061 
4062 static ssize_t
4063 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
4064 {
4065 	char *e;
4066 	unsigned long long new = simple_strtoull(buf, &e, 10);
4067 	if (mddev->pers)
4068 		return -EBUSY;
4069 	if (buf == e || (*e && *e != '\n'))
4070 		return -EINVAL;
4071 	mddev->reshape_position = new;
4072 	mddev->delta_disks = 0;
4073 	mddev->new_level = mddev->level;
4074 	mddev->new_layout = mddev->layout;
4075 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4076 	return len;
4077 }
4078 
4079 static struct md_sysfs_entry md_reshape_position =
4080 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4081        reshape_position_store);
4082 
4083 static ssize_t
4084 array_size_show(mddev_t *mddev, char *page)
4085 {
4086 	if (mddev->external_size)
4087 		return sprintf(page, "%llu\n",
4088 			       (unsigned long long)mddev->array_sectors/2);
4089 	else
4090 		return sprintf(page, "default\n");
4091 }
4092 
4093 static ssize_t
4094 array_size_store(mddev_t *mddev, const char *buf, size_t len)
4095 {
4096 	sector_t sectors;
4097 
4098 	if (strncmp(buf, "default", 7) == 0) {
4099 		if (mddev->pers)
4100 			sectors = mddev->pers->size(mddev, 0, 0);
4101 		else
4102 			sectors = mddev->array_sectors;
4103 
4104 		mddev->external_size = 0;
4105 	} else {
4106 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4107 			return -EINVAL;
4108 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4109 			return -E2BIG;
4110 
4111 		mddev->external_size = 1;
4112 	}
4113 
4114 	mddev->array_sectors = sectors;
4115 	set_capacity(mddev->gendisk, mddev->array_sectors);
4116 	if (mddev->pers)
4117 		revalidate_disk(mddev->gendisk);
4118 
4119 	return len;
4120 }
4121 
4122 static struct md_sysfs_entry md_array_size =
4123 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4124        array_size_store);
4125 
4126 static struct attribute *md_default_attrs[] = {
4127 	&md_level.attr,
4128 	&md_layout.attr,
4129 	&md_raid_disks.attr,
4130 	&md_chunk_size.attr,
4131 	&md_size.attr,
4132 	&md_resync_start.attr,
4133 	&md_metadata.attr,
4134 	&md_new_device.attr,
4135 	&md_safe_delay.attr,
4136 	&md_array_state.attr,
4137 	&md_reshape_position.attr,
4138 	&md_array_size.attr,
4139 	&max_corr_read_errors.attr,
4140 	NULL,
4141 };
4142 
4143 static struct attribute *md_redundancy_attrs[] = {
4144 	&md_scan_mode.attr,
4145 	&md_mismatches.attr,
4146 	&md_sync_min.attr,
4147 	&md_sync_max.attr,
4148 	&md_sync_speed.attr,
4149 	&md_sync_force_parallel.attr,
4150 	&md_sync_completed.attr,
4151 	&md_min_sync.attr,
4152 	&md_max_sync.attr,
4153 	&md_suspend_lo.attr,
4154 	&md_suspend_hi.attr,
4155 	&md_bitmap.attr,
4156 	&md_degraded.attr,
4157 	NULL,
4158 };
4159 static struct attribute_group md_redundancy_group = {
4160 	.name = NULL,
4161 	.attrs = md_redundancy_attrs,
4162 };
4163 
4164 
4165 static ssize_t
4166 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4167 {
4168 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4169 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4170 	ssize_t rv;
4171 
4172 	if (!entry->show)
4173 		return -EIO;
4174 	rv = mddev_lock(mddev);
4175 	if (!rv) {
4176 		rv = entry->show(mddev, page);
4177 		mddev_unlock(mddev);
4178 	}
4179 	return rv;
4180 }
4181 
4182 static ssize_t
4183 md_attr_store(struct kobject *kobj, struct attribute *attr,
4184 	      const char *page, size_t length)
4185 {
4186 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4187 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4188 	ssize_t rv;
4189 
4190 	if (!entry->store)
4191 		return -EIO;
4192 	if (!capable(CAP_SYS_ADMIN))
4193 		return -EACCES;
4194 	rv = mddev_lock(mddev);
4195 	if (mddev->hold_active == UNTIL_IOCTL)
4196 		mddev->hold_active = 0;
4197 	if (!rv) {
4198 		rv = entry->store(mddev, page, length);
4199 		mddev_unlock(mddev);
4200 	}
4201 	return rv;
4202 }
4203 
4204 static void md_free(struct kobject *ko)
4205 {
4206 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
4207 
4208 	if (mddev->sysfs_state)
4209 		sysfs_put(mddev->sysfs_state);
4210 
4211 	if (mddev->gendisk) {
4212 		del_gendisk(mddev->gendisk);
4213 		put_disk(mddev->gendisk);
4214 	}
4215 	if (mddev->queue)
4216 		blk_cleanup_queue(mddev->queue);
4217 
4218 	kfree(mddev);
4219 }
4220 
4221 static const struct sysfs_ops md_sysfs_ops = {
4222 	.show	= md_attr_show,
4223 	.store	= md_attr_store,
4224 };
4225 static struct kobj_type md_ktype = {
4226 	.release	= md_free,
4227 	.sysfs_ops	= &md_sysfs_ops,
4228 	.default_attrs	= md_default_attrs,
4229 };
4230 
4231 int mdp_major = 0;
4232 
4233 static void mddev_delayed_delete(struct work_struct *ws)
4234 {
4235 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
4236 
4237 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4238 	kobject_del(&mddev->kobj);
4239 	kobject_put(&mddev->kobj);
4240 }
4241 
4242 static int md_alloc(dev_t dev, char *name)
4243 {
4244 	static DEFINE_MUTEX(disks_mutex);
4245 	mddev_t *mddev = mddev_find(dev);
4246 	struct gendisk *disk;
4247 	int partitioned;
4248 	int shift;
4249 	int unit;
4250 	int error;
4251 
4252 	if (!mddev)
4253 		return -ENODEV;
4254 
4255 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4256 	shift = partitioned ? MdpMinorShift : 0;
4257 	unit = MINOR(mddev->unit) >> shift;
4258 
4259 	/* wait for any previous instance if this device
4260 	 * to be completed removed (mddev_delayed_delete).
4261 	 */
4262 	flush_scheduled_work();
4263 
4264 	mutex_lock(&disks_mutex);
4265 	error = -EEXIST;
4266 	if (mddev->gendisk)
4267 		goto abort;
4268 
4269 	if (name) {
4270 		/* Need to ensure that 'name' is not a duplicate.
4271 		 */
4272 		mddev_t *mddev2;
4273 		spin_lock(&all_mddevs_lock);
4274 
4275 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4276 			if (mddev2->gendisk &&
4277 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4278 				spin_unlock(&all_mddevs_lock);
4279 				goto abort;
4280 			}
4281 		spin_unlock(&all_mddevs_lock);
4282 	}
4283 
4284 	error = -ENOMEM;
4285 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4286 	if (!mddev->queue)
4287 		goto abort;
4288 	mddev->queue->queuedata = mddev;
4289 
4290 	/* Can be unlocked because the queue is new: no concurrency */
4291 	queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
4292 
4293 	blk_queue_make_request(mddev->queue, md_make_request);
4294 
4295 	disk = alloc_disk(1 << shift);
4296 	if (!disk) {
4297 		blk_cleanup_queue(mddev->queue);
4298 		mddev->queue = NULL;
4299 		goto abort;
4300 	}
4301 	disk->major = MAJOR(mddev->unit);
4302 	disk->first_minor = unit << shift;
4303 	if (name)
4304 		strcpy(disk->disk_name, name);
4305 	else if (partitioned)
4306 		sprintf(disk->disk_name, "md_d%d", unit);
4307 	else
4308 		sprintf(disk->disk_name, "md%d", unit);
4309 	disk->fops = &md_fops;
4310 	disk->private_data = mddev;
4311 	disk->queue = mddev->queue;
4312 	/* Allow extended partitions.  This makes the
4313 	 * 'mdp' device redundant, but we can't really
4314 	 * remove it now.
4315 	 */
4316 	disk->flags |= GENHD_FL_EXT_DEVT;
4317 	add_disk(disk);
4318 	mddev->gendisk = disk;
4319 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4320 				     &disk_to_dev(disk)->kobj, "%s", "md");
4321 	if (error) {
4322 		/* This isn't possible, but as kobject_init_and_add is marked
4323 		 * __must_check, we must do something with the result
4324 		 */
4325 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4326 		       disk->disk_name);
4327 		error = 0;
4328 	}
4329 	if (mddev->kobj.sd &&
4330 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4331 		printk(KERN_DEBUG "pointless warning\n");
4332  abort:
4333 	mutex_unlock(&disks_mutex);
4334 	if (!error && mddev->kobj.sd) {
4335 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4336 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4337 	}
4338 	mddev_put(mddev);
4339 	return error;
4340 }
4341 
4342 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4343 {
4344 	md_alloc(dev, NULL);
4345 	return NULL;
4346 }
4347 
4348 static int add_named_array(const char *val, struct kernel_param *kp)
4349 {
4350 	/* val must be "md_*" where * is not all digits.
4351 	 * We allocate an array with a large free minor number, and
4352 	 * set the name to val.  val must not already be an active name.
4353 	 */
4354 	int len = strlen(val);
4355 	char buf[DISK_NAME_LEN];
4356 
4357 	while (len && val[len-1] == '\n')
4358 		len--;
4359 	if (len >= DISK_NAME_LEN)
4360 		return -E2BIG;
4361 	strlcpy(buf, val, len+1);
4362 	if (strncmp(buf, "md_", 3) != 0)
4363 		return -EINVAL;
4364 	return md_alloc(0, buf);
4365 }
4366 
4367 static void md_safemode_timeout(unsigned long data)
4368 {
4369 	mddev_t *mddev = (mddev_t *) data;
4370 
4371 	if (!atomic_read(&mddev->writes_pending)) {
4372 		mddev->safemode = 1;
4373 		if (mddev->external)
4374 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4375 	}
4376 	md_wakeup_thread(mddev->thread);
4377 }
4378 
4379 static int start_dirty_degraded;
4380 
4381 int md_run(mddev_t *mddev)
4382 {
4383 	int err;
4384 	mdk_rdev_t *rdev;
4385 	struct mdk_personality *pers;
4386 
4387 	if (list_empty(&mddev->disks))
4388 		/* cannot run an array with no devices.. */
4389 		return -EINVAL;
4390 
4391 	if (mddev->pers)
4392 		return -EBUSY;
4393 	/* Cannot run until previous stop completes properly */
4394 	if (mddev->sysfs_active)
4395 		return -EBUSY;
4396 
4397 	/*
4398 	 * Analyze all RAID superblock(s)
4399 	 */
4400 	if (!mddev->raid_disks) {
4401 		if (!mddev->persistent)
4402 			return -EINVAL;
4403 		analyze_sbs(mddev);
4404 	}
4405 
4406 	if (mddev->level != LEVEL_NONE)
4407 		request_module("md-level-%d", mddev->level);
4408 	else if (mddev->clevel[0])
4409 		request_module("md-%s", mddev->clevel);
4410 
4411 	/*
4412 	 * Drop all container device buffers, from now on
4413 	 * the only valid external interface is through the md
4414 	 * device.
4415 	 */
4416 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4417 		if (test_bit(Faulty, &rdev->flags))
4418 			continue;
4419 		sync_blockdev(rdev->bdev);
4420 		invalidate_bdev(rdev->bdev);
4421 
4422 		/* perform some consistency tests on the device.
4423 		 * We don't want the data to overlap the metadata,
4424 		 * Internal Bitmap issues have been handled elsewhere.
4425 		 */
4426 		if (rdev->data_offset < rdev->sb_start) {
4427 			if (mddev->dev_sectors &&
4428 			    rdev->data_offset + mddev->dev_sectors
4429 			    > rdev->sb_start) {
4430 				printk("md: %s: data overlaps metadata\n",
4431 				       mdname(mddev));
4432 				return -EINVAL;
4433 			}
4434 		} else {
4435 			if (rdev->sb_start + rdev->sb_size/512
4436 			    > rdev->data_offset) {
4437 				printk("md: %s: metadata overlaps data\n",
4438 				       mdname(mddev));
4439 				return -EINVAL;
4440 			}
4441 		}
4442 		sysfs_notify_dirent_safe(rdev->sysfs_state);
4443 	}
4444 
4445 	spin_lock(&pers_lock);
4446 	pers = find_pers(mddev->level, mddev->clevel);
4447 	if (!pers || !try_module_get(pers->owner)) {
4448 		spin_unlock(&pers_lock);
4449 		if (mddev->level != LEVEL_NONE)
4450 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4451 			       mddev->level);
4452 		else
4453 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4454 			       mddev->clevel);
4455 		return -EINVAL;
4456 	}
4457 	mddev->pers = pers;
4458 	spin_unlock(&pers_lock);
4459 	if (mddev->level != pers->level) {
4460 		mddev->level = pers->level;
4461 		mddev->new_level = pers->level;
4462 	}
4463 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4464 
4465 	if (mddev->reshape_position != MaxSector &&
4466 	    pers->start_reshape == NULL) {
4467 		/* This personality cannot handle reshaping... */
4468 		mddev->pers = NULL;
4469 		module_put(pers->owner);
4470 		return -EINVAL;
4471 	}
4472 
4473 	if (pers->sync_request) {
4474 		/* Warn if this is a potentially silly
4475 		 * configuration.
4476 		 */
4477 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4478 		mdk_rdev_t *rdev2;
4479 		int warned = 0;
4480 
4481 		list_for_each_entry(rdev, &mddev->disks, same_set)
4482 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4483 				if (rdev < rdev2 &&
4484 				    rdev->bdev->bd_contains ==
4485 				    rdev2->bdev->bd_contains) {
4486 					printk(KERN_WARNING
4487 					       "%s: WARNING: %s appears to be"
4488 					       " on the same physical disk as"
4489 					       " %s.\n",
4490 					       mdname(mddev),
4491 					       bdevname(rdev->bdev,b),
4492 					       bdevname(rdev2->bdev,b2));
4493 					warned = 1;
4494 				}
4495 			}
4496 
4497 		if (warned)
4498 			printk(KERN_WARNING
4499 			       "True protection against single-disk"
4500 			       " failure might be compromised.\n");
4501 	}
4502 
4503 	mddev->recovery = 0;
4504 	/* may be over-ridden by personality */
4505 	mddev->resync_max_sectors = mddev->dev_sectors;
4506 
4507 	mddev->barriers_work = 1;
4508 	mddev->ok_start_degraded = start_dirty_degraded;
4509 
4510 	if (start_readonly && mddev->ro == 0)
4511 		mddev->ro = 2; /* read-only, but switch on first write */
4512 
4513 	err = mddev->pers->run(mddev);
4514 	if (err)
4515 		printk(KERN_ERR "md: pers->run() failed ...\n");
4516 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4517 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4518 			  " but 'external_size' not in effect?\n", __func__);
4519 		printk(KERN_ERR
4520 		       "md: invalid array_size %llu > default size %llu\n",
4521 		       (unsigned long long)mddev->array_sectors / 2,
4522 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4523 		err = -EINVAL;
4524 		mddev->pers->stop(mddev);
4525 	}
4526 	if (err == 0 && mddev->pers->sync_request) {
4527 		err = bitmap_create(mddev);
4528 		if (err) {
4529 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4530 			       mdname(mddev), err);
4531 			mddev->pers->stop(mddev);
4532 		}
4533 	}
4534 	if (err) {
4535 		module_put(mddev->pers->owner);
4536 		mddev->pers = NULL;
4537 		bitmap_destroy(mddev);
4538 		return err;
4539 	}
4540 	if (mddev->pers->sync_request) {
4541 		if (mddev->kobj.sd &&
4542 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4543 			printk(KERN_WARNING
4544 			       "md: cannot register extra attributes for %s\n",
4545 			       mdname(mddev));
4546 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
4547 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4548 		mddev->ro = 0;
4549 
4550  	atomic_set(&mddev->writes_pending,0);
4551 	atomic_set(&mddev->max_corr_read_errors,
4552 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
4553 	mddev->safemode = 0;
4554 	mddev->safemode_timer.function = md_safemode_timeout;
4555 	mddev->safemode_timer.data = (unsigned long) mddev;
4556 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4557 	mddev->in_sync = 1;
4558 
4559 	list_for_each_entry(rdev, &mddev->disks, same_set)
4560 		if (rdev->raid_disk >= 0) {
4561 			char nm[20];
4562 			sprintf(nm, "rd%d", rdev->raid_disk);
4563 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
4564 				/* failure here is OK */;
4565 		}
4566 
4567 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4568 
4569 	if (mddev->flags)
4570 		md_update_sb(mddev, 0);
4571 
4572 	md_wakeup_thread(mddev->thread);
4573 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4574 
4575 	md_new_event(mddev);
4576 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4577 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4578 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4579 	return 0;
4580 }
4581 EXPORT_SYMBOL_GPL(md_run);
4582 
4583 static int do_md_run(mddev_t *mddev)
4584 {
4585 	int err;
4586 
4587 	err = md_run(mddev);
4588 	if (err)
4589 		goto out;
4590 	err = bitmap_load(mddev);
4591 	if (err) {
4592 		bitmap_destroy(mddev);
4593 		goto out;
4594 	}
4595 	set_capacity(mddev->gendisk, mddev->array_sectors);
4596 	revalidate_disk(mddev->gendisk);
4597 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4598 out:
4599 	return err;
4600 }
4601 
4602 static int restart_array(mddev_t *mddev)
4603 {
4604 	struct gendisk *disk = mddev->gendisk;
4605 
4606 	/* Complain if it has no devices */
4607 	if (list_empty(&mddev->disks))
4608 		return -ENXIO;
4609 	if (!mddev->pers)
4610 		return -EINVAL;
4611 	if (!mddev->ro)
4612 		return -EBUSY;
4613 	mddev->safemode = 0;
4614 	mddev->ro = 0;
4615 	set_disk_ro(disk, 0);
4616 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4617 		mdname(mddev));
4618 	/* Kick recovery or resync if necessary */
4619 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4620 	md_wakeup_thread(mddev->thread);
4621 	md_wakeup_thread(mddev->sync_thread);
4622 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4623 	return 0;
4624 }
4625 
4626 /* similar to deny_write_access, but accounts for our holding a reference
4627  * to the file ourselves */
4628 static int deny_bitmap_write_access(struct file * file)
4629 {
4630 	struct inode *inode = file->f_mapping->host;
4631 
4632 	spin_lock(&inode->i_lock);
4633 	if (atomic_read(&inode->i_writecount) > 1) {
4634 		spin_unlock(&inode->i_lock);
4635 		return -ETXTBSY;
4636 	}
4637 	atomic_set(&inode->i_writecount, -1);
4638 	spin_unlock(&inode->i_lock);
4639 
4640 	return 0;
4641 }
4642 
4643 void restore_bitmap_write_access(struct file *file)
4644 {
4645 	struct inode *inode = file->f_mapping->host;
4646 
4647 	spin_lock(&inode->i_lock);
4648 	atomic_set(&inode->i_writecount, 1);
4649 	spin_unlock(&inode->i_lock);
4650 }
4651 
4652 static void md_clean(mddev_t *mddev)
4653 {
4654 	mddev->array_sectors = 0;
4655 	mddev->external_size = 0;
4656 	mddev->dev_sectors = 0;
4657 	mddev->raid_disks = 0;
4658 	mddev->recovery_cp = 0;
4659 	mddev->resync_min = 0;
4660 	mddev->resync_max = MaxSector;
4661 	mddev->reshape_position = MaxSector;
4662 	mddev->external = 0;
4663 	mddev->persistent = 0;
4664 	mddev->level = LEVEL_NONE;
4665 	mddev->clevel[0] = 0;
4666 	mddev->flags = 0;
4667 	mddev->ro = 0;
4668 	mddev->metadata_type[0] = 0;
4669 	mddev->chunk_sectors = 0;
4670 	mddev->ctime = mddev->utime = 0;
4671 	mddev->layout = 0;
4672 	mddev->max_disks = 0;
4673 	mddev->events = 0;
4674 	mddev->can_decrease_events = 0;
4675 	mddev->delta_disks = 0;
4676 	mddev->new_level = LEVEL_NONE;
4677 	mddev->new_layout = 0;
4678 	mddev->new_chunk_sectors = 0;
4679 	mddev->curr_resync = 0;
4680 	mddev->resync_mismatches = 0;
4681 	mddev->suspend_lo = mddev->suspend_hi = 0;
4682 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
4683 	mddev->recovery = 0;
4684 	mddev->in_sync = 0;
4685 	mddev->degraded = 0;
4686 	mddev->barriers_work = 0;
4687 	mddev->safemode = 0;
4688 	mddev->bitmap_info.offset = 0;
4689 	mddev->bitmap_info.default_offset = 0;
4690 	mddev->bitmap_info.chunksize = 0;
4691 	mddev->bitmap_info.daemon_sleep = 0;
4692 	mddev->bitmap_info.max_write_behind = 0;
4693 	mddev->plug = NULL;
4694 }
4695 
4696 void md_stop_writes(mddev_t *mddev)
4697 {
4698 	if (mddev->sync_thread) {
4699 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4700 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4701 		md_unregister_thread(mddev->sync_thread);
4702 		mddev->sync_thread = NULL;
4703 	}
4704 
4705 	del_timer_sync(&mddev->safemode_timer);
4706 
4707 	bitmap_flush(mddev);
4708 	md_super_wait(mddev);
4709 
4710 	if (!mddev->in_sync || mddev->flags) {
4711 		/* mark array as shutdown cleanly */
4712 		mddev->in_sync = 1;
4713 		md_update_sb(mddev, 1);
4714 	}
4715 }
4716 EXPORT_SYMBOL_GPL(md_stop_writes);
4717 
4718 void md_stop(mddev_t *mddev)
4719 {
4720 	mddev->pers->stop(mddev);
4721 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
4722 		mddev->to_remove = &md_redundancy_group;
4723 	module_put(mddev->pers->owner);
4724 	mddev->pers = NULL;
4725 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4726 }
4727 EXPORT_SYMBOL_GPL(md_stop);
4728 
4729 static int md_set_readonly(mddev_t *mddev, int is_open)
4730 {
4731 	int err = 0;
4732 	mutex_lock(&mddev->open_mutex);
4733 	if (atomic_read(&mddev->openers) > is_open) {
4734 		printk("md: %s still in use.\n",mdname(mddev));
4735 		err = -EBUSY;
4736 		goto out;
4737 	}
4738 	if (mddev->pers) {
4739 		md_stop_writes(mddev);
4740 
4741 		err  = -ENXIO;
4742 		if (mddev->ro==1)
4743 			goto out;
4744 		mddev->ro = 1;
4745 		set_disk_ro(mddev->gendisk, 1);
4746 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4747 		sysfs_notify_dirent_safe(mddev->sysfs_state);
4748 		err = 0;
4749 	}
4750 out:
4751 	mutex_unlock(&mddev->open_mutex);
4752 	return err;
4753 }
4754 
4755 /* mode:
4756  *   0 - completely stop and dis-assemble array
4757  *   2 - stop but do not disassemble array
4758  */
4759 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4760 {
4761 	struct gendisk *disk = mddev->gendisk;
4762 	mdk_rdev_t *rdev;
4763 
4764 	mutex_lock(&mddev->open_mutex);
4765 	if (atomic_read(&mddev->openers) > is_open ||
4766 	    mddev->sysfs_active) {
4767 		printk("md: %s still in use.\n",mdname(mddev));
4768 		mutex_unlock(&mddev->open_mutex);
4769 		return -EBUSY;
4770 	}
4771 
4772 	if (mddev->pers) {
4773 		if (mddev->ro)
4774 			set_disk_ro(disk, 0);
4775 
4776 		md_stop_writes(mddev);
4777 		md_stop(mddev);
4778 		mddev->queue->merge_bvec_fn = NULL;
4779 		mddev->queue->unplug_fn = NULL;
4780 		mddev->queue->backing_dev_info.congested_fn = NULL;
4781 
4782 		/* tell userspace to handle 'inactive' */
4783 		sysfs_notify_dirent_safe(mddev->sysfs_state);
4784 
4785 		list_for_each_entry(rdev, &mddev->disks, same_set)
4786 			if (rdev->raid_disk >= 0) {
4787 				char nm[20];
4788 				sprintf(nm, "rd%d", rdev->raid_disk);
4789 				sysfs_remove_link(&mddev->kobj, nm);
4790 			}
4791 
4792 		set_capacity(disk, 0);
4793 		mutex_unlock(&mddev->open_mutex);
4794 		revalidate_disk(disk);
4795 
4796 		if (mddev->ro)
4797 			mddev->ro = 0;
4798 	} else
4799 		mutex_unlock(&mddev->open_mutex);
4800 	/*
4801 	 * Free resources if final stop
4802 	 */
4803 	if (mode == 0) {
4804 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4805 
4806 		bitmap_destroy(mddev);
4807 		if (mddev->bitmap_info.file) {
4808 			restore_bitmap_write_access(mddev->bitmap_info.file);
4809 			fput(mddev->bitmap_info.file);
4810 			mddev->bitmap_info.file = NULL;
4811 		}
4812 		mddev->bitmap_info.offset = 0;
4813 
4814 		export_array(mddev);
4815 
4816 		md_clean(mddev);
4817 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4818 		if (mddev->hold_active == UNTIL_STOP)
4819 			mddev->hold_active = 0;
4820 	}
4821 	blk_integrity_unregister(disk);
4822 	md_new_event(mddev);
4823 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4824 	return 0;
4825 }
4826 
4827 #ifndef MODULE
4828 static void autorun_array(mddev_t *mddev)
4829 {
4830 	mdk_rdev_t *rdev;
4831 	int err;
4832 
4833 	if (list_empty(&mddev->disks))
4834 		return;
4835 
4836 	printk(KERN_INFO "md: running: ");
4837 
4838 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4839 		char b[BDEVNAME_SIZE];
4840 		printk("<%s>", bdevname(rdev->bdev,b));
4841 	}
4842 	printk("\n");
4843 
4844 	err = do_md_run(mddev);
4845 	if (err) {
4846 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4847 		do_md_stop(mddev, 0, 0);
4848 	}
4849 }
4850 
4851 /*
4852  * lets try to run arrays based on all disks that have arrived
4853  * until now. (those are in pending_raid_disks)
4854  *
4855  * the method: pick the first pending disk, collect all disks with
4856  * the same UUID, remove all from the pending list and put them into
4857  * the 'same_array' list. Then order this list based on superblock
4858  * update time (freshest comes first), kick out 'old' disks and
4859  * compare superblocks. If everything's fine then run it.
4860  *
4861  * If "unit" is allocated, then bump its reference count
4862  */
4863 static void autorun_devices(int part)
4864 {
4865 	mdk_rdev_t *rdev0, *rdev, *tmp;
4866 	mddev_t *mddev;
4867 	char b[BDEVNAME_SIZE];
4868 
4869 	printk(KERN_INFO "md: autorun ...\n");
4870 	while (!list_empty(&pending_raid_disks)) {
4871 		int unit;
4872 		dev_t dev;
4873 		LIST_HEAD(candidates);
4874 		rdev0 = list_entry(pending_raid_disks.next,
4875 					 mdk_rdev_t, same_set);
4876 
4877 		printk(KERN_INFO "md: considering %s ...\n",
4878 			bdevname(rdev0->bdev,b));
4879 		INIT_LIST_HEAD(&candidates);
4880 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4881 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4882 				printk(KERN_INFO "md:  adding %s ...\n",
4883 					bdevname(rdev->bdev,b));
4884 				list_move(&rdev->same_set, &candidates);
4885 			}
4886 		/*
4887 		 * now we have a set of devices, with all of them having
4888 		 * mostly sane superblocks. It's time to allocate the
4889 		 * mddev.
4890 		 */
4891 		if (part) {
4892 			dev = MKDEV(mdp_major,
4893 				    rdev0->preferred_minor << MdpMinorShift);
4894 			unit = MINOR(dev) >> MdpMinorShift;
4895 		} else {
4896 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4897 			unit = MINOR(dev);
4898 		}
4899 		if (rdev0->preferred_minor != unit) {
4900 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4901 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4902 			break;
4903 		}
4904 
4905 		md_probe(dev, NULL, NULL);
4906 		mddev = mddev_find(dev);
4907 		if (!mddev || !mddev->gendisk) {
4908 			if (mddev)
4909 				mddev_put(mddev);
4910 			printk(KERN_ERR
4911 				"md: cannot allocate memory for md drive.\n");
4912 			break;
4913 		}
4914 		if (mddev_lock(mddev))
4915 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4916 			       mdname(mddev));
4917 		else if (mddev->raid_disks || mddev->major_version
4918 			 || !list_empty(&mddev->disks)) {
4919 			printk(KERN_WARNING
4920 				"md: %s already running, cannot run %s\n",
4921 				mdname(mddev), bdevname(rdev0->bdev,b));
4922 			mddev_unlock(mddev);
4923 		} else {
4924 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4925 			mddev->persistent = 1;
4926 			rdev_for_each_list(rdev, tmp, &candidates) {
4927 				list_del_init(&rdev->same_set);
4928 				if (bind_rdev_to_array(rdev, mddev))
4929 					export_rdev(rdev);
4930 			}
4931 			autorun_array(mddev);
4932 			mddev_unlock(mddev);
4933 		}
4934 		/* on success, candidates will be empty, on error
4935 		 * it won't...
4936 		 */
4937 		rdev_for_each_list(rdev, tmp, &candidates) {
4938 			list_del_init(&rdev->same_set);
4939 			export_rdev(rdev);
4940 		}
4941 		mddev_put(mddev);
4942 	}
4943 	printk(KERN_INFO "md: ... autorun DONE.\n");
4944 }
4945 #endif /* !MODULE */
4946 
4947 static int get_version(void __user * arg)
4948 {
4949 	mdu_version_t ver;
4950 
4951 	ver.major = MD_MAJOR_VERSION;
4952 	ver.minor = MD_MINOR_VERSION;
4953 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4954 
4955 	if (copy_to_user(arg, &ver, sizeof(ver)))
4956 		return -EFAULT;
4957 
4958 	return 0;
4959 }
4960 
4961 static int get_array_info(mddev_t * mddev, void __user * arg)
4962 {
4963 	mdu_array_info_t info;
4964 	int nr,working,insync,failed,spare;
4965 	mdk_rdev_t *rdev;
4966 
4967 	nr=working=insync=failed=spare=0;
4968 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4969 		nr++;
4970 		if (test_bit(Faulty, &rdev->flags))
4971 			failed++;
4972 		else {
4973 			working++;
4974 			if (test_bit(In_sync, &rdev->flags))
4975 				insync++;
4976 			else
4977 				spare++;
4978 		}
4979 	}
4980 
4981 	info.major_version = mddev->major_version;
4982 	info.minor_version = mddev->minor_version;
4983 	info.patch_version = MD_PATCHLEVEL_VERSION;
4984 	info.ctime         = mddev->ctime;
4985 	info.level         = mddev->level;
4986 	info.size          = mddev->dev_sectors / 2;
4987 	if (info.size != mddev->dev_sectors / 2) /* overflow */
4988 		info.size = -1;
4989 	info.nr_disks      = nr;
4990 	info.raid_disks    = mddev->raid_disks;
4991 	info.md_minor      = mddev->md_minor;
4992 	info.not_persistent= !mddev->persistent;
4993 
4994 	info.utime         = mddev->utime;
4995 	info.state         = 0;
4996 	if (mddev->in_sync)
4997 		info.state = (1<<MD_SB_CLEAN);
4998 	if (mddev->bitmap && mddev->bitmap_info.offset)
4999 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5000 	info.active_disks  = insync;
5001 	info.working_disks = working;
5002 	info.failed_disks  = failed;
5003 	info.spare_disks   = spare;
5004 
5005 	info.layout        = mddev->layout;
5006 	info.chunk_size    = mddev->chunk_sectors << 9;
5007 
5008 	if (copy_to_user(arg, &info, sizeof(info)))
5009 		return -EFAULT;
5010 
5011 	return 0;
5012 }
5013 
5014 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
5015 {
5016 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5017 	char *ptr, *buf = NULL;
5018 	int err = -ENOMEM;
5019 
5020 	if (md_allow_write(mddev))
5021 		file = kmalloc(sizeof(*file), GFP_NOIO);
5022 	else
5023 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5024 
5025 	if (!file)
5026 		goto out;
5027 
5028 	/* bitmap disabled, zero the first byte and copy out */
5029 	if (!mddev->bitmap || !mddev->bitmap->file) {
5030 		file->pathname[0] = '\0';
5031 		goto copy_out;
5032 	}
5033 
5034 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5035 	if (!buf)
5036 		goto out;
5037 
5038 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
5039 	if (IS_ERR(ptr))
5040 		goto out;
5041 
5042 	strcpy(file->pathname, ptr);
5043 
5044 copy_out:
5045 	err = 0;
5046 	if (copy_to_user(arg, file, sizeof(*file)))
5047 		err = -EFAULT;
5048 out:
5049 	kfree(buf);
5050 	kfree(file);
5051 	return err;
5052 }
5053 
5054 static int get_disk_info(mddev_t * mddev, void __user * arg)
5055 {
5056 	mdu_disk_info_t info;
5057 	mdk_rdev_t *rdev;
5058 
5059 	if (copy_from_user(&info, arg, sizeof(info)))
5060 		return -EFAULT;
5061 
5062 	rdev = find_rdev_nr(mddev, info.number);
5063 	if (rdev) {
5064 		info.major = MAJOR(rdev->bdev->bd_dev);
5065 		info.minor = MINOR(rdev->bdev->bd_dev);
5066 		info.raid_disk = rdev->raid_disk;
5067 		info.state = 0;
5068 		if (test_bit(Faulty, &rdev->flags))
5069 			info.state |= (1<<MD_DISK_FAULTY);
5070 		else if (test_bit(In_sync, &rdev->flags)) {
5071 			info.state |= (1<<MD_DISK_ACTIVE);
5072 			info.state |= (1<<MD_DISK_SYNC);
5073 		}
5074 		if (test_bit(WriteMostly, &rdev->flags))
5075 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5076 	} else {
5077 		info.major = info.minor = 0;
5078 		info.raid_disk = -1;
5079 		info.state = (1<<MD_DISK_REMOVED);
5080 	}
5081 
5082 	if (copy_to_user(arg, &info, sizeof(info)))
5083 		return -EFAULT;
5084 
5085 	return 0;
5086 }
5087 
5088 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5089 {
5090 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5091 	mdk_rdev_t *rdev;
5092 	dev_t dev = MKDEV(info->major,info->minor);
5093 
5094 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5095 		return -EOVERFLOW;
5096 
5097 	if (!mddev->raid_disks) {
5098 		int err;
5099 		/* expecting a device which has a superblock */
5100 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5101 		if (IS_ERR(rdev)) {
5102 			printk(KERN_WARNING
5103 				"md: md_import_device returned %ld\n",
5104 				PTR_ERR(rdev));
5105 			return PTR_ERR(rdev);
5106 		}
5107 		if (!list_empty(&mddev->disks)) {
5108 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
5109 							mdk_rdev_t, same_set);
5110 			err = super_types[mddev->major_version]
5111 				.load_super(rdev, rdev0, mddev->minor_version);
5112 			if (err < 0) {
5113 				printk(KERN_WARNING
5114 					"md: %s has different UUID to %s\n",
5115 					bdevname(rdev->bdev,b),
5116 					bdevname(rdev0->bdev,b2));
5117 				export_rdev(rdev);
5118 				return -EINVAL;
5119 			}
5120 		}
5121 		err = bind_rdev_to_array(rdev, mddev);
5122 		if (err)
5123 			export_rdev(rdev);
5124 		return err;
5125 	}
5126 
5127 	/*
5128 	 * add_new_disk can be used once the array is assembled
5129 	 * to add "hot spares".  They must already have a superblock
5130 	 * written
5131 	 */
5132 	if (mddev->pers) {
5133 		int err;
5134 		if (!mddev->pers->hot_add_disk) {
5135 			printk(KERN_WARNING
5136 				"%s: personality does not support diskops!\n",
5137 			       mdname(mddev));
5138 			return -EINVAL;
5139 		}
5140 		if (mddev->persistent)
5141 			rdev = md_import_device(dev, mddev->major_version,
5142 						mddev->minor_version);
5143 		else
5144 			rdev = md_import_device(dev, -1, -1);
5145 		if (IS_ERR(rdev)) {
5146 			printk(KERN_WARNING
5147 				"md: md_import_device returned %ld\n",
5148 				PTR_ERR(rdev));
5149 			return PTR_ERR(rdev);
5150 		}
5151 		/* set save_raid_disk if appropriate */
5152 		if (!mddev->persistent) {
5153 			if (info->state & (1<<MD_DISK_SYNC)  &&
5154 			    info->raid_disk < mddev->raid_disks)
5155 				rdev->raid_disk = info->raid_disk;
5156 			else
5157 				rdev->raid_disk = -1;
5158 		} else
5159 			super_types[mddev->major_version].
5160 				validate_super(mddev, rdev);
5161 		rdev->saved_raid_disk = rdev->raid_disk;
5162 
5163 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5164 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5165 			set_bit(WriteMostly, &rdev->flags);
5166 		else
5167 			clear_bit(WriteMostly, &rdev->flags);
5168 
5169 		rdev->raid_disk = -1;
5170 		err = bind_rdev_to_array(rdev, mddev);
5171 		if (!err && !mddev->pers->hot_remove_disk) {
5172 			/* If there is hot_add_disk but no hot_remove_disk
5173 			 * then added disks for geometry changes,
5174 			 * and should be added immediately.
5175 			 */
5176 			super_types[mddev->major_version].
5177 				validate_super(mddev, rdev);
5178 			err = mddev->pers->hot_add_disk(mddev, rdev);
5179 			if (err)
5180 				unbind_rdev_from_array(rdev);
5181 		}
5182 		if (err)
5183 			export_rdev(rdev);
5184 		else
5185 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5186 
5187 		md_update_sb(mddev, 1);
5188 		if (mddev->degraded)
5189 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5190 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5191 		md_wakeup_thread(mddev->thread);
5192 		return err;
5193 	}
5194 
5195 	/* otherwise, add_new_disk is only allowed
5196 	 * for major_version==0 superblocks
5197 	 */
5198 	if (mddev->major_version != 0) {
5199 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5200 		       mdname(mddev));
5201 		return -EINVAL;
5202 	}
5203 
5204 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5205 		int err;
5206 		rdev = md_import_device(dev, -1, 0);
5207 		if (IS_ERR(rdev)) {
5208 			printk(KERN_WARNING
5209 				"md: error, md_import_device() returned %ld\n",
5210 				PTR_ERR(rdev));
5211 			return PTR_ERR(rdev);
5212 		}
5213 		rdev->desc_nr = info->number;
5214 		if (info->raid_disk < mddev->raid_disks)
5215 			rdev->raid_disk = info->raid_disk;
5216 		else
5217 			rdev->raid_disk = -1;
5218 
5219 		if (rdev->raid_disk < mddev->raid_disks)
5220 			if (info->state & (1<<MD_DISK_SYNC))
5221 				set_bit(In_sync, &rdev->flags);
5222 
5223 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5224 			set_bit(WriteMostly, &rdev->flags);
5225 
5226 		if (!mddev->persistent) {
5227 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5228 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
5229 		} else
5230 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
5231 		rdev->sectors = rdev->sb_start;
5232 
5233 		err = bind_rdev_to_array(rdev, mddev);
5234 		if (err) {
5235 			export_rdev(rdev);
5236 			return err;
5237 		}
5238 	}
5239 
5240 	return 0;
5241 }
5242 
5243 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
5244 {
5245 	char b[BDEVNAME_SIZE];
5246 	mdk_rdev_t *rdev;
5247 
5248 	rdev = find_rdev(mddev, dev);
5249 	if (!rdev)
5250 		return -ENXIO;
5251 
5252 	if (rdev->raid_disk >= 0)
5253 		goto busy;
5254 
5255 	kick_rdev_from_array(rdev);
5256 	md_update_sb(mddev, 1);
5257 	md_new_event(mddev);
5258 
5259 	return 0;
5260 busy:
5261 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5262 		bdevname(rdev->bdev,b), mdname(mddev));
5263 	return -EBUSY;
5264 }
5265 
5266 static int hot_add_disk(mddev_t * mddev, dev_t dev)
5267 {
5268 	char b[BDEVNAME_SIZE];
5269 	int err;
5270 	mdk_rdev_t *rdev;
5271 
5272 	if (!mddev->pers)
5273 		return -ENODEV;
5274 
5275 	if (mddev->major_version != 0) {
5276 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5277 			" version-0 superblocks.\n",
5278 			mdname(mddev));
5279 		return -EINVAL;
5280 	}
5281 	if (!mddev->pers->hot_add_disk) {
5282 		printk(KERN_WARNING
5283 			"%s: personality does not support diskops!\n",
5284 			mdname(mddev));
5285 		return -EINVAL;
5286 	}
5287 
5288 	rdev = md_import_device(dev, -1, 0);
5289 	if (IS_ERR(rdev)) {
5290 		printk(KERN_WARNING
5291 			"md: error, md_import_device() returned %ld\n",
5292 			PTR_ERR(rdev));
5293 		return -EINVAL;
5294 	}
5295 
5296 	if (mddev->persistent)
5297 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
5298 	else
5299 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
5300 
5301 	rdev->sectors = rdev->sb_start;
5302 
5303 	if (test_bit(Faulty, &rdev->flags)) {
5304 		printk(KERN_WARNING
5305 			"md: can not hot-add faulty %s disk to %s!\n",
5306 			bdevname(rdev->bdev,b), mdname(mddev));
5307 		err = -EINVAL;
5308 		goto abort_export;
5309 	}
5310 	clear_bit(In_sync, &rdev->flags);
5311 	rdev->desc_nr = -1;
5312 	rdev->saved_raid_disk = -1;
5313 	err = bind_rdev_to_array(rdev, mddev);
5314 	if (err)
5315 		goto abort_export;
5316 
5317 	/*
5318 	 * The rest should better be atomic, we can have disk failures
5319 	 * noticed in interrupt contexts ...
5320 	 */
5321 
5322 	rdev->raid_disk = -1;
5323 
5324 	md_update_sb(mddev, 1);
5325 
5326 	/*
5327 	 * Kick recovery, maybe this spare has to be added to the
5328 	 * array immediately.
5329 	 */
5330 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5331 	md_wakeup_thread(mddev->thread);
5332 	md_new_event(mddev);
5333 	return 0;
5334 
5335 abort_export:
5336 	export_rdev(rdev);
5337 	return err;
5338 }
5339 
5340 static int set_bitmap_file(mddev_t *mddev, int fd)
5341 {
5342 	int err;
5343 
5344 	if (mddev->pers) {
5345 		if (!mddev->pers->quiesce)
5346 			return -EBUSY;
5347 		if (mddev->recovery || mddev->sync_thread)
5348 			return -EBUSY;
5349 		/* we should be able to change the bitmap.. */
5350 	}
5351 
5352 
5353 	if (fd >= 0) {
5354 		if (mddev->bitmap)
5355 			return -EEXIST; /* cannot add when bitmap is present */
5356 		mddev->bitmap_info.file = fget(fd);
5357 
5358 		if (mddev->bitmap_info.file == NULL) {
5359 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5360 			       mdname(mddev));
5361 			return -EBADF;
5362 		}
5363 
5364 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5365 		if (err) {
5366 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5367 			       mdname(mddev));
5368 			fput(mddev->bitmap_info.file);
5369 			mddev->bitmap_info.file = NULL;
5370 			return err;
5371 		}
5372 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5373 	} else if (mddev->bitmap == NULL)
5374 		return -ENOENT; /* cannot remove what isn't there */
5375 	err = 0;
5376 	if (mddev->pers) {
5377 		mddev->pers->quiesce(mddev, 1);
5378 		if (fd >= 0) {
5379 			err = bitmap_create(mddev);
5380 			if (!err)
5381 				err = bitmap_load(mddev);
5382 		}
5383 		if (fd < 0 || err) {
5384 			bitmap_destroy(mddev);
5385 			fd = -1; /* make sure to put the file */
5386 		}
5387 		mddev->pers->quiesce(mddev, 0);
5388 	}
5389 	if (fd < 0) {
5390 		if (mddev->bitmap_info.file) {
5391 			restore_bitmap_write_access(mddev->bitmap_info.file);
5392 			fput(mddev->bitmap_info.file);
5393 		}
5394 		mddev->bitmap_info.file = NULL;
5395 	}
5396 
5397 	return err;
5398 }
5399 
5400 /*
5401  * set_array_info is used two different ways
5402  * The original usage is when creating a new array.
5403  * In this usage, raid_disks is > 0 and it together with
5404  *  level, size, not_persistent,layout,chunksize determine the
5405  *  shape of the array.
5406  *  This will always create an array with a type-0.90.0 superblock.
5407  * The newer usage is when assembling an array.
5408  *  In this case raid_disks will be 0, and the major_version field is
5409  *  use to determine which style super-blocks are to be found on the devices.
5410  *  The minor and patch _version numbers are also kept incase the
5411  *  super_block handler wishes to interpret them.
5412  */
5413 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5414 {
5415 
5416 	if (info->raid_disks == 0) {
5417 		/* just setting version number for superblock loading */
5418 		if (info->major_version < 0 ||
5419 		    info->major_version >= ARRAY_SIZE(super_types) ||
5420 		    super_types[info->major_version].name == NULL) {
5421 			/* maybe try to auto-load a module? */
5422 			printk(KERN_INFO
5423 				"md: superblock version %d not known\n",
5424 				info->major_version);
5425 			return -EINVAL;
5426 		}
5427 		mddev->major_version = info->major_version;
5428 		mddev->minor_version = info->minor_version;
5429 		mddev->patch_version = info->patch_version;
5430 		mddev->persistent = !info->not_persistent;
5431 		/* ensure mddev_put doesn't delete this now that there
5432 		 * is some minimal configuration.
5433 		 */
5434 		mddev->ctime         = get_seconds();
5435 		return 0;
5436 	}
5437 	mddev->major_version = MD_MAJOR_VERSION;
5438 	mddev->minor_version = MD_MINOR_VERSION;
5439 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5440 	mddev->ctime         = get_seconds();
5441 
5442 	mddev->level         = info->level;
5443 	mddev->clevel[0]     = 0;
5444 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5445 	mddev->raid_disks    = info->raid_disks;
5446 	/* don't set md_minor, it is determined by which /dev/md* was
5447 	 * openned
5448 	 */
5449 	if (info->state & (1<<MD_SB_CLEAN))
5450 		mddev->recovery_cp = MaxSector;
5451 	else
5452 		mddev->recovery_cp = 0;
5453 	mddev->persistent    = ! info->not_persistent;
5454 	mddev->external	     = 0;
5455 
5456 	mddev->layout        = info->layout;
5457 	mddev->chunk_sectors = info->chunk_size >> 9;
5458 
5459 	mddev->max_disks     = MD_SB_DISKS;
5460 
5461 	if (mddev->persistent)
5462 		mddev->flags         = 0;
5463 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5464 
5465 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
5466 	mddev->bitmap_info.offset = 0;
5467 
5468 	mddev->reshape_position = MaxSector;
5469 
5470 	/*
5471 	 * Generate a 128 bit UUID
5472 	 */
5473 	get_random_bytes(mddev->uuid, 16);
5474 
5475 	mddev->new_level = mddev->level;
5476 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5477 	mddev->new_layout = mddev->layout;
5478 	mddev->delta_disks = 0;
5479 
5480 	return 0;
5481 }
5482 
5483 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5484 {
5485 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5486 
5487 	if (mddev->external_size)
5488 		return;
5489 
5490 	mddev->array_sectors = array_sectors;
5491 }
5492 EXPORT_SYMBOL(md_set_array_sectors);
5493 
5494 static int update_size(mddev_t *mddev, sector_t num_sectors)
5495 {
5496 	mdk_rdev_t *rdev;
5497 	int rv;
5498 	int fit = (num_sectors == 0);
5499 
5500 	if (mddev->pers->resize == NULL)
5501 		return -EINVAL;
5502 	/* The "num_sectors" is the number of sectors of each device that
5503 	 * is used.  This can only make sense for arrays with redundancy.
5504 	 * linear and raid0 always use whatever space is available. We can only
5505 	 * consider changing this number if no resync or reconstruction is
5506 	 * happening, and if the new size is acceptable. It must fit before the
5507 	 * sb_start or, if that is <data_offset, it must fit before the size
5508 	 * of each device.  If num_sectors is zero, we find the largest size
5509 	 * that fits.
5510 
5511 	 */
5512 	if (mddev->sync_thread)
5513 		return -EBUSY;
5514 	if (mddev->bitmap)
5515 		/* Sorry, cannot grow a bitmap yet, just remove it,
5516 		 * grow, and re-add.
5517 		 */
5518 		return -EBUSY;
5519 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5520 		sector_t avail = rdev->sectors;
5521 
5522 		if (fit && (num_sectors == 0 || num_sectors > avail))
5523 			num_sectors = avail;
5524 		if (avail < num_sectors)
5525 			return -ENOSPC;
5526 	}
5527 	rv = mddev->pers->resize(mddev, num_sectors);
5528 	if (!rv)
5529 		revalidate_disk(mddev->gendisk);
5530 	return rv;
5531 }
5532 
5533 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5534 {
5535 	int rv;
5536 	/* change the number of raid disks */
5537 	if (mddev->pers->check_reshape == NULL)
5538 		return -EINVAL;
5539 	if (raid_disks <= 0 ||
5540 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
5541 		return -EINVAL;
5542 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5543 		return -EBUSY;
5544 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5545 
5546 	rv = mddev->pers->check_reshape(mddev);
5547 	return rv;
5548 }
5549 
5550 
5551 /*
5552  * update_array_info is used to change the configuration of an
5553  * on-line array.
5554  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5555  * fields in the info are checked against the array.
5556  * Any differences that cannot be handled will cause an error.
5557  * Normally, only one change can be managed at a time.
5558  */
5559 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5560 {
5561 	int rv = 0;
5562 	int cnt = 0;
5563 	int state = 0;
5564 
5565 	/* calculate expected state,ignoring low bits */
5566 	if (mddev->bitmap && mddev->bitmap_info.offset)
5567 		state |= (1 << MD_SB_BITMAP_PRESENT);
5568 
5569 	if (mddev->major_version != info->major_version ||
5570 	    mddev->minor_version != info->minor_version ||
5571 /*	    mddev->patch_version != info->patch_version || */
5572 	    mddev->ctime         != info->ctime         ||
5573 	    mddev->level         != info->level         ||
5574 /*	    mddev->layout        != info->layout        || */
5575 	    !mddev->persistent	 != info->not_persistent||
5576 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5577 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5578 	    ((state^info->state) & 0xfffffe00)
5579 		)
5580 		return -EINVAL;
5581 	/* Check there is only one change */
5582 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5583 		cnt++;
5584 	if (mddev->raid_disks != info->raid_disks)
5585 		cnt++;
5586 	if (mddev->layout != info->layout)
5587 		cnt++;
5588 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5589 		cnt++;
5590 	if (cnt == 0)
5591 		return 0;
5592 	if (cnt > 1)
5593 		return -EINVAL;
5594 
5595 	if (mddev->layout != info->layout) {
5596 		/* Change layout
5597 		 * we don't need to do anything at the md level, the
5598 		 * personality will take care of it all.
5599 		 */
5600 		if (mddev->pers->check_reshape == NULL)
5601 			return -EINVAL;
5602 		else {
5603 			mddev->new_layout = info->layout;
5604 			rv = mddev->pers->check_reshape(mddev);
5605 			if (rv)
5606 				mddev->new_layout = mddev->layout;
5607 			return rv;
5608 		}
5609 	}
5610 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5611 		rv = update_size(mddev, (sector_t)info->size * 2);
5612 
5613 	if (mddev->raid_disks    != info->raid_disks)
5614 		rv = update_raid_disks(mddev, info->raid_disks);
5615 
5616 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5617 		if (mddev->pers->quiesce == NULL)
5618 			return -EINVAL;
5619 		if (mddev->recovery || mddev->sync_thread)
5620 			return -EBUSY;
5621 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5622 			/* add the bitmap */
5623 			if (mddev->bitmap)
5624 				return -EEXIST;
5625 			if (mddev->bitmap_info.default_offset == 0)
5626 				return -EINVAL;
5627 			mddev->bitmap_info.offset =
5628 				mddev->bitmap_info.default_offset;
5629 			mddev->pers->quiesce(mddev, 1);
5630 			rv = bitmap_create(mddev);
5631 			if (!rv)
5632 				rv = bitmap_load(mddev);
5633 			if (rv)
5634 				bitmap_destroy(mddev);
5635 			mddev->pers->quiesce(mddev, 0);
5636 		} else {
5637 			/* remove the bitmap */
5638 			if (!mddev->bitmap)
5639 				return -ENOENT;
5640 			if (mddev->bitmap->file)
5641 				return -EINVAL;
5642 			mddev->pers->quiesce(mddev, 1);
5643 			bitmap_destroy(mddev);
5644 			mddev->pers->quiesce(mddev, 0);
5645 			mddev->bitmap_info.offset = 0;
5646 		}
5647 	}
5648 	md_update_sb(mddev, 1);
5649 	return rv;
5650 }
5651 
5652 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5653 {
5654 	mdk_rdev_t *rdev;
5655 
5656 	if (mddev->pers == NULL)
5657 		return -ENODEV;
5658 
5659 	rdev = find_rdev(mddev, dev);
5660 	if (!rdev)
5661 		return -ENODEV;
5662 
5663 	md_error(mddev, rdev);
5664 	return 0;
5665 }
5666 
5667 /*
5668  * We have a problem here : there is no easy way to give a CHS
5669  * virtual geometry. We currently pretend that we have a 2 heads
5670  * 4 sectors (with a BIG number of cylinders...). This drives
5671  * dosfs just mad... ;-)
5672  */
5673 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5674 {
5675 	mddev_t *mddev = bdev->bd_disk->private_data;
5676 
5677 	geo->heads = 2;
5678 	geo->sectors = 4;
5679 	geo->cylinders = mddev->array_sectors / 8;
5680 	return 0;
5681 }
5682 
5683 static int md_ioctl(struct block_device *bdev, fmode_t mode,
5684 			unsigned int cmd, unsigned long arg)
5685 {
5686 	int err = 0;
5687 	void __user *argp = (void __user *)arg;
5688 	mddev_t *mddev = NULL;
5689 	int ro;
5690 
5691 	if (!capable(CAP_SYS_ADMIN))
5692 		return -EACCES;
5693 
5694 	/*
5695 	 * Commands dealing with the RAID driver but not any
5696 	 * particular array:
5697 	 */
5698 	switch (cmd)
5699 	{
5700 		case RAID_VERSION:
5701 			err = get_version(argp);
5702 			goto done;
5703 
5704 		case PRINT_RAID_DEBUG:
5705 			err = 0;
5706 			md_print_devices();
5707 			goto done;
5708 
5709 #ifndef MODULE
5710 		case RAID_AUTORUN:
5711 			err = 0;
5712 			autostart_arrays(arg);
5713 			goto done;
5714 #endif
5715 		default:;
5716 	}
5717 
5718 	/*
5719 	 * Commands creating/starting a new array:
5720 	 */
5721 
5722 	mddev = bdev->bd_disk->private_data;
5723 
5724 	if (!mddev) {
5725 		BUG();
5726 		goto abort;
5727 	}
5728 
5729 	err = mddev_lock(mddev);
5730 	if (err) {
5731 		printk(KERN_INFO
5732 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5733 			err, cmd);
5734 		goto abort;
5735 	}
5736 
5737 	switch (cmd)
5738 	{
5739 		case SET_ARRAY_INFO:
5740 			{
5741 				mdu_array_info_t info;
5742 				if (!arg)
5743 					memset(&info, 0, sizeof(info));
5744 				else if (copy_from_user(&info, argp, sizeof(info))) {
5745 					err = -EFAULT;
5746 					goto abort_unlock;
5747 				}
5748 				if (mddev->pers) {
5749 					err = update_array_info(mddev, &info);
5750 					if (err) {
5751 						printk(KERN_WARNING "md: couldn't update"
5752 						       " array info. %d\n", err);
5753 						goto abort_unlock;
5754 					}
5755 					goto done_unlock;
5756 				}
5757 				if (!list_empty(&mddev->disks)) {
5758 					printk(KERN_WARNING
5759 					       "md: array %s already has disks!\n",
5760 					       mdname(mddev));
5761 					err = -EBUSY;
5762 					goto abort_unlock;
5763 				}
5764 				if (mddev->raid_disks) {
5765 					printk(KERN_WARNING
5766 					       "md: array %s already initialised!\n",
5767 					       mdname(mddev));
5768 					err = -EBUSY;
5769 					goto abort_unlock;
5770 				}
5771 				err = set_array_info(mddev, &info);
5772 				if (err) {
5773 					printk(KERN_WARNING "md: couldn't set"
5774 					       " array info. %d\n", err);
5775 					goto abort_unlock;
5776 				}
5777 			}
5778 			goto done_unlock;
5779 
5780 		default:;
5781 	}
5782 
5783 	/*
5784 	 * Commands querying/configuring an existing array:
5785 	 */
5786 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5787 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5788 	if ((!mddev->raid_disks && !mddev->external)
5789 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5790 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5791 	    && cmd != GET_BITMAP_FILE) {
5792 		err = -ENODEV;
5793 		goto abort_unlock;
5794 	}
5795 
5796 	/*
5797 	 * Commands even a read-only array can execute:
5798 	 */
5799 	switch (cmd)
5800 	{
5801 		case GET_ARRAY_INFO:
5802 			err = get_array_info(mddev, argp);
5803 			goto done_unlock;
5804 
5805 		case GET_BITMAP_FILE:
5806 			err = get_bitmap_file(mddev, argp);
5807 			goto done_unlock;
5808 
5809 		case GET_DISK_INFO:
5810 			err = get_disk_info(mddev, argp);
5811 			goto done_unlock;
5812 
5813 		case RESTART_ARRAY_RW:
5814 			err = restart_array(mddev);
5815 			goto done_unlock;
5816 
5817 		case STOP_ARRAY:
5818 			err = do_md_stop(mddev, 0, 1);
5819 			goto done_unlock;
5820 
5821 		case STOP_ARRAY_RO:
5822 			err = md_set_readonly(mddev, 1);
5823 			goto done_unlock;
5824 
5825 		case BLKROSET:
5826 			if (get_user(ro, (int __user *)(arg))) {
5827 				err = -EFAULT;
5828 				goto done_unlock;
5829 			}
5830 			err = -EINVAL;
5831 
5832 			/* if the bdev is going readonly the value of mddev->ro
5833 			 * does not matter, no writes are coming
5834 			 */
5835 			if (ro)
5836 				goto done_unlock;
5837 
5838 			/* are we are already prepared for writes? */
5839 			if (mddev->ro != 1)
5840 				goto done_unlock;
5841 
5842 			/* transitioning to readauto need only happen for
5843 			 * arrays that call md_write_start
5844 			 */
5845 			if (mddev->pers) {
5846 				err = restart_array(mddev);
5847 				if (err == 0) {
5848 					mddev->ro = 2;
5849 					set_disk_ro(mddev->gendisk, 0);
5850 				}
5851 			}
5852 			goto done_unlock;
5853 	}
5854 
5855 	/*
5856 	 * The remaining ioctls are changing the state of the
5857 	 * superblock, so we do not allow them on read-only arrays.
5858 	 * However non-MD ioctls (e.g. get-size) will still come through
5859 	 * here and hit the 'default' below, so only disallow
5860 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5861 	 */
5862 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5863 		if (mddev->ro == 2) {
5864 			mddev->ro = 0;
5865 			sysfs_notify_dirent_safe(mddev->sysfs_state);
5866 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5867 			md_wakeup_thread(mddev->thread);
5868 		} else {
5869 			err = -EROFS;
5870 			goto abort_unlock;
5871 		}
5872 	}
5873 
5874 	switch (cmd)
5875 	{
5876 		case ADD_NEW_DISK:
5877 		{
5878 			mdu_disk_info_t info;
5879 			if (copy_from_user(&info, argp, sizeof(info)))
5880 				err = -EFAULT;
5881 			else
5882 				err = add_new_disk(mddev, &info);
5883 			goto done_unlock;
5884 		}
5885 
5886 		case HOT_REMOVE_DISK:
5887 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5888 			goto done_unlock;
5889 
5890 		case HOT_ADD_DISK:
5891 			err = hot_add_disk(mddev, new_decode_dev(arg));
5892 			goto done_unlock;
5893 
5894 		case SET_DISK_FAULTY:
5895 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5896 			goto done_unlock;
5897 
5898 		case RUN_ARRAY:
5899 			err = do_md_run(mddev);
5900 			goto done_unlock;
5901 
5902 		case SET_BITMAP_FILE:
5903 			err = set_bitmap_file(mddev, (int)arg);
5904 			goto done_unlock;
5905 
5906 		default:
5907 			err = -EINVAL;
5908 			goto abort_unlock;
5909 	}
5910 
5911 done_unlock:
5912 abort_unlock:
5913 	if (mddev->hold_active == UNTIL_IOCTL &&
5914 	    err != -EINVAL)
5915 		mddev->hold_active = 0;
5916 	mddev_unlock(mddev);
5917 
5918 	return err;
5919 done:
5920 	if (err)
5921 		MD_BUG();
5922 abort:
5923 	return err;
5924 }
5925 #ifdef CONFIG_COMPAT
5926 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
5927 		    unsigned int cmd, unsigned long arg)
5928 {
5929 	switch (cmd) {
5930 	case HOT_REMOVE_DISK:
5931 	case HOT_ADD_DISK:
5932 	case SET_DISK_FAULTY:
5933 	case SET_BITMAP_FILE:
5934 		/* These take in integer arg, do not convert */
5935 		break;
5936 	default:
5937 		arg = (unsigned long)compat_ptr(arg);
5938 		break;
5939 	}
5940 
5941 	return md_ioctl(bdev, mode, cmd, arg);
5942 }
5943 #endif /* CONFIG_COMPAT */
5944 
5945 static int md_open(struct block_device *bdev, fmode_t mode)
5946 {
5947 	/*
5948 	 * Succeed if we can lock the mddev, which confirms that
5949 	 * it isn't being stopped right now.
5950 	 */
5951 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5952 	int err;
5953 
5954 	lock_kernel();
5955 	if (mddev->gendisk != bdev->bd_disk) {
5956 		/* we are racing with mddev_put which is discarding this
5957 		 * bd_disk.
5958 		 */
5959 		mddev_put(mddev);
5960 		/* Wait until bdev->bd_disk is definitely gone */
5961 		flush_scheduled_work();
5962 		/* Then retry the open from the top */
5963 		unlock_kernel();
5964 		return -ERESTARTSYS;
5965 	}
5966 	BUG_ON(mddev != bdev->bd_disk->private_data);
5967 
5968 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
5969 		goto out;
5970 
5971 	err = 0;
5972 	atomic_inc(&mddev->openers);
5973 	mutex_unlock(&mddev->open_mutex);
5974 
5975 	check_disk_size_change(mddev->gendisk, bdev);
5976  out:
5977 	unlock_kernel();
5978 	return err;
5979 }
5980 
5981 static int md_release(struct gendisk *disk, fmode_t mode)
5982 {
5983  	mddev_t *mddev = disk->private_data;
5984 
5985 	BUG_ON(!mddev);
5986 	lock_kernel();
5987 	atomic_dec(&mddev->openers);
5988 	mddev_put(mddev);
5989 	unlock_kernel();
5990 
5991 	return 0;
5992 }
5993 static const struct block_device_operations md_fops =
5994 {
5995 	.owner		= THIS_MODULE,
5996 	.open		= md_open,
5997 	.release	= md_release,
5998 	.ioctl		= md_ioctl,
5999 #ifdef CONFIG_COMPAT
6000 	.compat_ioctl	= md_compat_ioctl,
6001 #endif
6002 	.getgeo		= md_getgeo,
6003 };
6004 
6005 static int md_thread(void * arg)
6006 {
6007 	mdk_thread_t *thread = arg;
6008 
6009 	/*
6010 	 * md_thread is a 'system-thread', it's priority should be very
6011 	 * high. We avoid resource deadlocks individually in each
6012 	 * raid personality. (RAID5 does preallocation) We also use RR and
6013 	 * the very same RT priority as kswapd, thus we will never get
6014 	 * into a priority inversion deadlock.
6015 	 *
6016 	 * we definitely have to have equal or higher priority than
6017 	 * bdflush, otherwise bdflush will deadlock if there are too
6018 	 * many dirty RAID5 blocks.
6019 	 */
6020 
6021 	allow_signal(SIGKILL);
6022 	while (!kthread_should_stop()) {
6023 
6024 		/* We need to wait INTERRUPTIBLE so that
6025 		 * we don't add to the load-average.
6026 		 * That means we need to be sure no signals are
6027 		 * pending
6028 		 */
6029 		if (signal_pending(current))
6030 			flush_signals(current);
6031 
6032 		wait_event_interruptible_timeout
6033 			(thread->wqueue,
6034 			 test_bit(THREAD_WAKEUP, &thread->flags)
6035 			 || kthread_should_stop(),
6036 			 thread->timeout);
6037 
6038 		clear_bit(THREAD_WAKEUP, &thread->flags);
6039 
6040 		thread->run(thread->mddev);
6041 	}
6042 
6043 	return 0;
6044 }
6045 
6046 void md_wakeup_thread(mdk_thread_t *thread)
6047 {
6048 	if (thread) {
6049 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
6050 		set_bit(THREAD_WAKEUP, &thread->flags);
6051 		wake_up(&thread->wqueue);
6052 	}
6053 }
6054 
6055 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
6056 				 const char *name)
6057 {
6058 	mdk_thread_t *thread;
6059 
6060 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
6061 	if (!thread)
6062 		return NULL;
6063 
6064 	init_waitqueue_head(&thread->wqueue);
6065 
6066 	thread->run = run;
6067 	thread->mddev = mddev;
6068 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6069 	thread->tsk = kthread_run(md_thread, thread,
6070 				  "%s_%s",
6071 				  mdname(thread->mddev),
6072 				  name ?: mddev->pers->name);
6073 	if (IS_ERR(thread->tsk)) {
6074 		kfree(thread);
6075 		return NULL;
6076 	}
6077 	return thread;
6078 }
6079 
6080 void md_unregister_thread(mdk_thread_t *thread)
6081 {
6082 	if (!thread)
6083 		return;
6084 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6085 
6086 	kthread_stop(thread->tsk);
6087 	kfree(thread);
6088 }
6089 
6090 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
6091 {
6092 	if (!mddev) {
6093 		MD_BUG();
6094 		return;
6095 	}
6096 
6097 	if (!rdev || test_bit(Faulty, &rdev->flags))
6098 		return;
6099 
6100 	if (mddev->external)
6101 		set_bit(Blocked, &rdev->flags);
6102 /*
6103 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
6104 		mdname(mddev),
6105 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
6106 		__builtin_return_address(0),__builtin_return_address(1),
6107 		__builtin_return_address(2),__builtin_return_address(3));
6108 */
6109 	if (!mddev->pers)
6110 		return;
6111 	if (!mddev->pers->error_handler)
6112 		return;
6113 	mddev->pers->error_handler(mddev,rdev);
6114 	if (mddev->degraded)
6115 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6116 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6117 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6118 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6119 	md_wakeup_thread(mddev->thread);
6120 	if (mddev->event_work.func)
6121 		schedule_work(&mddev->event_work);
6122 	md_new_event_inintr(mddev);
6123 }
6124 
6125 /* seq_file implementation /proc/mdstat */
6126 
6127 static void status_unused(struct seq_file *seq)
6128 {
6129 	int i = 0;
6130 	mdk_rdev_t *rdev;
6131 
6132 	seq_printf(seq, "unused devices: ");
6133 
6134 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6135 		char b[BDEVNAME_SIZE];
6136 		i++;
6137 		seq_printf(seq, "%s ",
6138 			      bdevname(rdev->bdev,b));
6139 	}
6140 	if (!i)
6141 		seq_printf(seq, "<none>");
6142 
6143 	seq_printf(seq, "\n");
6144 }
6145 
6146 
6147 static void status_resync(struct seq_file *seq, mddev_t * mddev)
6148 {
6149 	sector_t max_sectors, resync, res;
6150 	unsigned long dt, db;
6151 	sector_t rt;
6152 	int scale;
6153 	unsigned int per_milli;
6154 
6155 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6156 
6157 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6158 		max_sectors = mddev->resync_max_sectors;
6159 	else
6160 		max_sectors = mddev->dev_sectors;
6161 
6162 	/*
6163 	 * Should not happen.
6164 	 */
6165 	if (!max_sectors) {
6166 		MD_BUG();
6167 		return;
6168 	}
6169 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6170 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6171 	 * u32, as those are the requirements for sector_div.
6172 	 * Thus 'scale' must be at least 10
6173 	 */
6174 	scale = 10;
6175 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6176 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6177 			scale++;
6178 	}
6179 	res = (resync>>scale)*1000;
6180 	sector_div(res, (u32)((max_sectors>>scale)+1));
6181 
6182 	per_milli = res;
6183 	{
6184 		int i, x = per_milli/50, y = 20-x;
6185 		seq_printf(seq, "[");
6186 		for (i = 0; i < x; i++)
6187 			seq_printf(seq, "=");
6188 		seq_printf(seq, ">");
6189 		for (i = 0; i < y; i++)
6190 			seq_printf(seq, ".");
6191 		seq_printf(seq, "] ");
6192 	}
6193 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6194 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6195 		    "reshape" :
6196 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6197 		     "check" :
6198 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6199 		      "resync" : "recovery"))),
6200 		   per_milli/10, per_milli % 10,
6201 		   (unsigned long long) resync/2,
6202 		   (unsigned long long) max_sectors/2);
6203 
6204 	/*
6205 	 * dt: time from mark until now
6206 	 * db: blocks written from mark until now
6207 	 * rt: remaining time
6208 	 *
6209 	 * rt is a sector_t, so could be 32bit or 64bit.
6210 	 * So we divide before multiply in case it is 32bit and close
6211 	 * to the limit.
6212 	 * We scale the divisor (db) by 32 to avoid loosing precision
6213 	 * near the end of resync when the number of remaining sectors
6214 	 * is close to 'db'.
6215 	 * We then divide rt by 32 after multiplying by db to compensate.
6216 	 * The '+1' avoids division by zero if db is very small.
6217 	 */
6218 	dt = ((jiffies - mddev->resync_mark) / HZ);
6219 	if (!dt) dt++;
6220 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6221 		- mddev->resync_mark_cnt;
6222 
6223 	rt = max_sectors - resync;    /* number of remaining sectors */
6224 	sector_div(rt, db/32+1);
6225 	rt *= dt;
6226 	rt >>= 5;
6227 
6228 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6229 		   ((unsigned long)rt % 60)/6);
6230 
6231 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6232 }
6233 
6234 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6235 {
6236 	struct list_head *tmp;
6237 	loff_t l = *pos;
6238 	mddev_t *mddev;
6239 
6240 	if (l >= 0x10000)
6241 		return NULL;
6242 	if (!l--)
6243 		/* header */
6244 		return (void*)1;
6245 
6246 	spin_lock(&all_mddevs_lock);
6247 	list_for_each(tmp,&all_mddevs)
6248 		if (!l--) {
6249 			mddev = list_entry(tmp, mddev_t, all_mddevs);
6250 			mddev_get(mddev);
6251 			spin_unlock(&all_mddevs_lock);
6252 			return mddev;
6253 		}
6254 	spin_unlock(&all_mddevs_lock);
6255 	if (!l--)
6256 		return (void*)2;/* tail */
6257 	return NULL;
6258 }
6259 
6260 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6261 {
6262 	struct list_head *tmp;
6263 	mddev_t *next_mddev, *mddev = v;
6264 
6265 	++*pos;
6266 	if (v == (void*)2)
6267 		return NULL;
6268 
6269 	spin_lock(&all_mddevs_lock);
6270 	if (v == (void*)1)
6271 		tmp = all_mddevs.next;
6272 	else
6273 		tmp = mddev->all_mddevs.next;
6274 	if (tmp != &all_mddevs)
6275 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
6276 	else {
6277 		next_mddev = (void*)2;
6278 		*pos = 0x10000;
6279 	}
6280 	spin_unlock(&all_mddevs_lock);
6281 
6282 	if (v != (void*)1)
6283 		mddev_put(mddev);
6284 	return next_mddev;
6285 
6286 }
6287 
6288 static void md_seq_stop(struct seq_file *seq, void *v)
6289 {
6290 	mddev_t *mddev = v;
6291 
6292 	if (mddev && v != (void*)1 && v != (void*)2)
6293 		mddev_put(mddev);
6294 }
6295 
6296 struct mdstat_info {
6297 	int event;
6298 };
6299 
6300 static int md_seq_show(struct seq_file *seq, void *v)
6301 {
6302 	mddev_t *mddev = v;
6303 	sector_t sectors;
6304 	mdk_rdev_t *rdev;
6305 	struct mdstat_info *mi = seq->private;
6306 	struct bitmap *bitmap;
6307 
6308 	if (v == (void*)1) {
6309 		struct mdk_personality *pers;
6310 		seq_printf(seq, "Personalities : ");
6311 		spin_lock(&pers_lock);
6312 		list_for_each_entry(pers, &pers_list, list)
6313 			seq_printf(seq, "[%s] ", pers->name);
6314 
6315 		spin_unlock(&pers_lock);
6316 		seq_printf(seq, "\n");
6317 		mi->event = atomic_read(&md_event_count);
6318 		return 0;
6319 	}
6320 	if (v == (void*)2) {
6321 		status_unused(seq);
6322 		return 0;
6323 	}
6324 
6325 	if (mddev_lock(mddev) < 0)
6326 		return -EINTR;
6327 
6328 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6329 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6330 						mddev->pers ? "" : "in");
6331 		if (mddev->pers) {
6332 			if (mddev->ro==1)
6333 				seq_printf(seq, " (read-only)");
6334 			if (mddev->ro==2)
6335 				seq_printf(seq, " (auto-read-only)");
6336 			seq_printf(seq, " %s", mddev->pers->name);
6337 		}
6338 
6339 		sectors = 0;
6340 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6341 			char b[BDEVNAME_SIZE];
6342 			seq_printf(seq, " %s[%d]",
6343 				bdevname(rdev->bdev,b), rdev->desc_nr);
6344 			if (test_bit(WriteMostly, &rdev->flags))
6345 				seq_printf(seq, "(W)");
6346 			if (test_bit(Faulty, &rdev->flags)) {
6347 				seq_printf(seq, "(F)");
6348 				continue;
6349 			} else if (rdev->raid_disk < 0)
6350 				seq_printf(seq, "(S)"); /* spare */
6351 			sectors += rdev->sectors;
6352 		}
6353 
6354 		if (!list_empty(&mddev->disks)) {
6355 			if (mddev->pers)
6356 				seq_printf(seq, "\n      %llu blocks",
6357 					   (unsigned long long)
6358 					   mddev->array_sectors / 2);
6359 			else
6360 				seq_printf(seq, "\n      %llu blocks",
6361 					   (unsigned long long)sectors / 2);
6362 		}
6363 		if (mddev->persistent) {
6364 			if (mddev->major_version != 0 ||
6365 			    mddev->minor_version != 90) {
6366 				seq_printf(seq," super %d.%d",
6367 					   mddev->major_version,
6368 					   mddev->minor_version);
6369 			}
6370 		} else if (mddev->external)
6371 			seq_printf(seq, " super external:%s",
6372 				   mddev->metadata_type);
6373 		else
6374 			seq_printf(seq, " super non-persistent");
6375 
6376 		if (mddev->pers) {
6377 			mddev->pers->status(seq, mddev);
6378 	 		seq_printf(seq, "\n      ");
6379 			if (mddev->pers->sync_request) {
6380 				if (mddev->curr_resync > 2) {
6381 					status_resync(seq, mddev);
6382 					seq_printf(seq, "\n      ");
6383 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
6384 					seq_printf(seq, "\tresync=DELAYED\n      ");
6385 				else if (mddev->recovery_cp < MaxSector)
6386 					seq_printf(seq, "\tresync=PENDING\n      ");
6387 			}
6388 		} else
6389 			seq_printf(seq, "\n       ");
6390 
6391 		if ((bitmap = mddev->bitmap)) {
6392 			unsigned long chunk_kb;
6393 			unsigned long flags;
6394 			spin_lock_irqsave(&bitmap->lock, flags);
6395 			chunk_kb = mddev->bitmap_info.chunksize >> 10;
6396 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
6397 				"%lu%s chunk",
6398 				bitmap->pages - bitmap->missing_pages,
6399 				bitmap->pages,
6400 				(bitmap->pages - bitmap->missing_pages)
6401 					<< (PAGE_SHIFT - 10),
6402 				chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
6403 				chunk_kb ? "KB" : "B");
6404 			if (bitmap->file) {
6405 				seq_printf(seq, ", file: ");
6406 				seq_path(seq, &bitmap->file->f_path, " \t\n");
6407 			}
6408 
6409 			seq_printf(seq, "\n");
6410 			spin_unlock_irqrestore(&bitmap->lock, flags);
6411 		}
6412 
6413 		seq_printf(seq, "\n");
6414 	}
6415 	mddev_unlock(mddev);
6416 
6417 	return 0;
6418 }
6419 
6420 static const struct seq_operations md_seq_ops = {
6421 	.start  = md_seq_start,
6422 	.next   = md_seq_next,
6423 	.stop   = md_seq_stop,
6424 	.show   = md_seq_show,
6425 };
6426 
6427 static int md_seq_open(struct inode *inode, struct file *file)
6428 {
6429 	int error;
6430 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
6431 	if (mi == NULL)
6432 		return -ENOMEM;
6433 
6434 	error = seq_open(file, &md_seq_ops);
6435 	if (error)
6436 		kfree(mi);
6437 	else {
6438 		struct seq_file *p = file->private_data;
6439 		p->private = mi;
6440 		mi->event = atomic_read(&md_event_count);
6441 	}
6442 	return error;
6443 }
6444 
6445 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6446 {
6447 	struct seq_file *m = filp->private_data;
6448 	struct mdstat_info *mi = m->private;
6449 	int mask;
6450 
6451 	poll_wait(filp, &md_event_waiters, wait);
6452 
6453 	/* always allow read */
6454 	mask = POLLIN | POLLRDNORM;
6455 
6456 	if (mi->event != atomic_read(&md_event_count))
6457 		mask |= POLLERR | POLLPRI;
6458 	return mask;
6459 }
6460 
6461 static const struct file_operations md_seq_fops = {
6462 	.owner		= THIS_MODULE,
6463 	.open           = md_seq_open,
6464 	.read           = seq_read,
6465 	.llseek         = seq_lseek,
6466 	.release	= seq_release_private,
6467 	.poll		= mdstat_poll,
6468 };
6469 
6470 int register_md_personality(struct mdk_personality *p)
6471 {
6472 	spin_lock(&pers_lock);
6473 	list_add_tail(&p->list, &pers_list);
6474 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6475 	spin_unlock(&pers_lock);
6476 	return 0;
6477 }
6478 
6479 int unregister_md_personality(struct mdk_personality *p)
6480 {
6481 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6482 	spin_lock(&pers_lock);
6483 	list_del_init(&p->list);
6484 	spin_unlock(&pers_lock);
6485 	return 0;
6486 }
6487 
6488 static int is_mddev_idle(mddev_t *mddev, int init)
6489 {
6490 	mdk_rdev_t * rdev;
6491 	int idle;
6492 	int curr_events;
6493 
6494 	idle = 1;
6495 	rcu_read_lock();
6496 	rdev_for_each_rcu(rdev, mddev) {
6497 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6498 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6499 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6500 			      atomic_read(&disk->sync_io);
6501 		/* sync IO will cause sync_io to increase before the disk_stats
6502 		 * as sync_io is counted when a request starts, and
6503 		 * disk_stats is counted when it completes.
6504 		 * So resync activity will cause curr_events to be smaller than
6505 		 * when there was no such activity.
6506 		 * non-sync IO will cause disk_stat to increase without
6507 		 * increasing sync_io so curr_events will (eventually)
6508 		 * be larger than it was before.  Once it becomes
6509 		 * substantially larger, the test below will cause
6510 		 * the array to appear non-idle, and resync will slow
6511 		 * down.
6512 		 * If there is a lot of outstanding resync activity when
6513 		 * we set last_event to curr_events, then all that activity
6514 		 * completing might cause the array to appear non-idle
6515 		 * and resync will be slowed down even though there might
6516 		 * not have been non-resync activity.  This will only
6517 		 * happen once though.  'last_events' will soon reflect
6518 		 * the state where there is little or no outstanding
6519 		 * resync requests, and further resync activity will
6520 		 * always make curr_events less than last_events.
6521 		 *
6522 		 */
6523 		if (init || curr_events - rdev->last_events > 64) {
6524 			rdev->last_events = curr_events;
6525 			idle = 0;
6526 		}
6527 	}
6528 	rcu_read_unlock();
6529 	return idle;
6530 }
6531 
6532 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6533 {
6534 	/* another "blocks" (512byte) blocks have been synced */
6535 	atomic_sub(blocks, &mddev->recovery_active);
6536 	wake_up(&mddev->recovery_wait);
6537 	if (!ok) {
6538 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6539 		md_wakeup_thread(mddev->thread);
6540 		// stop recovery, signal do_sync ....
6541 	}
6542 }
6543 
6544 
6545 /* md_write_start(mddev, bi)
6546  * If we need to update some array metadata (e.g. 'active' flag
6547  * in superblock) before writing, schedule a superblock update
6548  * and wait for it to complete.
6549  */
6550 void md_write_start(mddev_t *mddev, struct bio *bi)
6551 {
6552 	int did_change = 0;
6553 	if (bio_data_dir(bi) != WRITE)
6554 		return;
6555 
6556 	BUG_ON(mddev->ro == 1);
6557 	if (mddev->ro == 2) {
6558 		/* need to switch to read/write */
6559 		mddev->ro = 0;
6560 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6561 		md_wakeup_thread(mddev->thread);
6562 		md_wakeup_thread(mddev->sync_thread);
6563 		did_change = 1;
6564 	}
6565 	atomic_inc(&mddev->writes_pending);
6566 	if (mddev->safemode == 1)
6567 		mddev->safemode = 0;
6568 	if (mddev->in_sync) {
6569 		spin_lock_irq(&mddev->write_lock);
6570 		if (mddev->in_sync) {
6571 			mddev->in_sync = 0;
6572 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6573 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
6574 			md_wakeup_thread(mddev->thread);
6575 			did_change = 1;
6576 		}
6577 		spin_unlock_irq(&mddev->write_lock);
6578 	}
6579 	if (did_change)
6580 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6581 	wait_event(mddev->sb_wait,
6582 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6583 }
6584 
6585 void md_write_end(mddev_t *mddev)
6586 {
6587 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6588 		if (mddev->safemode == 2)
6589 			md_wakeup_thread(mddev->thread);
6590 		else if (mddev->safemode_delay)
6591 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6592 	}
6593 }
6594 
6595 /* md_allow_write(mddev)
6596  * Calling this ensures that the array is marked 'active' so that writes
6597  * may proceed without blocking.  It is important to call this before
6598  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6599  * Must be called with mddev_lock held.
6600  *
6601  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6602  * is dropped, so return -EAGAIN after notifying userspace.
6603  */
6604 int md_allow_write(mddev_t *mddev)
6605 {
6606 	if (!mddev->pers)
6607 		return 0;
6608 	if (mddev->ro)
6609 		return 0;
6610 	if (!mddev->pers->sync_request)
6611 		return 0;
6612 
6613 	spin_lock_irq(&mddev->write_lock);
6614 	if (mddev->in_sync) {
6615 		mddev->in_sync = 0;
6616 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6617 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
6618 		if (mddev->safemode_delay &&
6619 		    mddev->safemode == 0)
6620 			mddev->safemode = 1;
6621 		spin_unlock_irq(&mddev->write_lock);
6622 		md_update_sb(mddev, 0);
6623 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6624 	} else
6625 		spin_unlock_irq(&mddev->write_lock);
6626 
6627 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
6628 		return -EAGAIN;
6629 	else
6630 		return 0;
6631 }
6632 EXPORT_SYMBOL_GPL(md_allow_write);
6633 
6634 void md_unplug(mddev_t *mddev)
6635 {
6636 	if (mddev->queue)
6637 		blk_unplug(mddev->queue);
6638 	if (mddev->plug)
6639 		mddev->plug->unplug_fn(mddev->plug);
6640 }
6641 
6642 #define SYNC_MARKS	10
6643 #define	SYNC_MARK_STEP	(3*HZ)
6644 void md_do_sync(mddev_t *mddev)
6645 {
6646 	mddev_t *mddev2;
6647 	unsigned int currspeed = 0,
6648 		 window;
6649 	sector_t max_sectors,j, io_sectors;
6650 	unsigned long mark[SYNC_MARKS];
6651 	sector_t mark_cnt[SYNC_MARKS];
6652 	int last_mark,m;
6653 	struct list_head *tmp;
6654 	sector_t last_check;
6655 	int skipped = 0;
6656 	mdk_rdev_t *rdev;
6657 	char *desc;
6658 
6659 	/* just incase thread restarts... */
6660 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6661 		return;
6662 	if (mddev->ro) /* never try to sync a read-only array */
6663 		return;
6664 
6665 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6666 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6667 			desc = "data-check";
6668 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6669 			desc = "requested-resync";
6670 		else
6671 			desc = "resync";
6672 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6673 		desc = "reshape";
6674 	else
6675 		desc = "recovery";
6676 
6677 	/* we overload curr_resync somewhat here.
6678 	 * 0 == not engaged in resync at all
6679 	 * 2 == checking that there is no conflict with another sync
6680 	 * 1 == like 2, but have yielded to allow conflicting resync to
6681 	 *		commense
6682 	 * other == active in resync - this many blocks
6683 	 *
6684 	 * Before starting a resync we must have set curr_resync to
6685 	 * 2, and then checked that every "conflicting" array has curr_resync
6686 	 * less than ours.  When we find one that is the same or higher
6687 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6688 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6689 	 * This will mean we have to start checking from the beginning again.
6690 	 *
6691 	 */
6692 
6693 	do {
6694 		mddev->curr_resync = 2;
6695 
6696 	try_again:
6697 		if (kthread_should_stop())
6698 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6699 
6700 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6701 			goto skip;
6702 		for_each_mddev(mddev2, tmp) {
6703 			if (mddev2 == mddev)
6704 				continue;
6705 			if (!mddev->parallel_resync
6706 			&&  mddev2->curr_resync
6707 			&&  match_mddev_units(mddev, mddev2)) {
6708 				DEFINE_WAIT(wq);
6709 				if (mddev < mddev2 && mddev->curr_resync == 2) {
6710 					/* arbitrarily yield */
6711 					mddev->curr_resync = 1;
6712 					wake_up(&resync_wait);
6713 				}
6714 				if (mddev > mddev2 && mddev->curr_resync == 1)
6715 					/* no need to wait here, we can wait the next
6716 					 * time 'round when curr_resync == 2
6717 					 */
6718 					continue;
6719 				/* We need to wait 'interruptible' so as not to
6720 				 * contribute to the load average, and not to
6721 				 * be caught by 'softlockup'
6722 				 */
6723 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
6724 				if (!kthread_should_stop() &&
6725 				    mddev2->curr_resync >= mddev->curr_resync) {
6726 					printk(KERN_INFO "md: delaying %s of %s"
6727 					       " until %s has finished (they"
6728 					       " share one or more physical units)\n",
6729 					       desc, mdname(mddev), mdname(mddev2));
6730 					mddev_put(mddev2);
6731 					if (signal_pending(current))
6732 						flush_signals(current);
6733 					schedule();
6734 					finish_wait(&resync_wait, &wq);
6735 					goto try_again;
6736 				}
6737 				finish_wait(&resync_wait, &wq);
6738 			}
6739 		}
6740 	} while (mddev->curr_resync < 2);
6741 
6742 	j = 0;
6743 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6744 		/* resync follows the size requested by the personality,
6745 		 * which defaults to physical size, but can be virtual size
6746 		 */
6747 		max_sectors = mddev->resync_max_sectors;
6748 		mddev->resync_mismatches = 0;
6749 		/* we don't use the checkpoint if there's a bitmap */
6750 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6751 			j = mddev->resync_min;
6752 		else if (!mddev->bitmap)
6753 			j = mddev->recovery_cp;
6754 
6755 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6756 		max_sectors = mddev->dev_sectors;
6757 	else {
6758 		/* recovery follows the physical size of devices */
6759 		max_sectors = mddev->dev_sectors;
6760 		j = MaxSector;
6761 		rcu_read_lock();
6762 		list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
6763 			if (rdev->raid_disk >= 0 &&
6764 			    !test_bit(Faulty, &rdev->flags) &&
6765 			    !test_bit(In_sync, &rdev->flags) &&
6766 			    rdev->recovery_offset < j)
6767 				j = rdev->recovery_offset;
6768 		rcu_read_unlock();
6769 	}
6770 
6771 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
6772 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
6773 		" %d KB/sec/disk.\n", speed_min(mddev));
6774 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6775 	       "(but not more than %d KB/sec) for %s.\n",
6776 	       speed_max(mddev), desc);
6777 
6778 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
6779 
6780 	io_sectors = 0;
6781 	for (m = 0; m < SYNC_MARKS; m++) {
6782 		mark[m] = jiffies;
6783 		mark_cnt[m] = io_sectors;
6784 	}
6785 	last_mark = 0;
6786 	mddev->resync_mark = mark[last_mark];
6787 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6788 
6789 	/*
6790 	 * Tune reconstruction:
6791 	 */
6792 	window = 32*(PAGE_SIZE/512);
6793 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6794 		window/2,(unsigned long long) max_sectors/2);
6795 
6796 	atomic_set(&mddev->recovery_active, 0);
6797 	last_check = 0;
6798 
6799 	if (j>2) {
6800 		printk(KERN_INFO
6801 		       "md: resuming %s of %s from checkpoint.\n",
6802 		       desc, mdname(mddev));
6803 		mddev->curr_resync = j;
6804 	}
6805 	mddev->curr_resync_completed = mddev->curr_resync;
6806 
6807 	while (j < max_sectors) {
6808 		sector_t sectors;
6809 
6810 		skipped = 0;
6811 
6812 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6813 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
6814 		      (mddev->curr_resync - mddev->curr_resync_completed)
6815 		      > (max_sectors >> 4)) ||
6816 		     (j - mddev->curr_resync_completed)*2
6817 		     >= mddev->resync_max - mddev->curr_resync_completed
6818 			    )) {
6819 			/* time to update curr_resync_completed */
6820 			md_unplug(mddev);
6821 			wait_event(mddev->recovery_wait,
6822 				   atomic_read(&mddev->recovery_active) == 0);
6823 			mddev->curr_resync_completed =
6824 				mddev->curr_resync;
6825 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6826 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6827 		}
6828 
6829 		while (j >= mddev->resync_max && !kthread_should_stop()) {
6830 			/* As this condition is controlled by user-space,
6831 			 * we can block indefinitely, so use '_interruptible'
6832 			 * to avoid triggering warnings.
6833 			 */
6834 			flush_signals(current); /* just in case */
6835 			wait_event_interruptible(mddev->recovery_wait,
6836 						 mddev->resync_max > j
6837 						 || kthread_should_stop());
6838 		}
6839 
6840 		if (kthread_should_stop())
6841 			goto interrupted;
6842 
6843 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6844 						  currspeed < speed_min(mddev));
6845 		if (sectors == 0) {
6846 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6847 			goto out;
6848 		}
6849 
6850 		if (!skipped) { /* actual IO requested */
6851 			io_sectors += sectors;
6852 			atomic_add(sectors, &mddev->recovery_active);
6853 		}
6854 
6855 		j += sectors;
6856 		if (j>1) mddev->curr_resync = j;
6857 		mddev->curr_mark_cnt = io_sectors;
6858 		if (last_check == 0)
6859 			/* this is the earliers that rebuilt will be
6860 			 * visible in /proc/mdstat
6861 			 */
6862 			md_new_event(mddev);
6863 
6864 		if (last_check + window > io_sectors || j == max_sectors)
6865 			continue;
6866 
6867 		last_check = io_sectors;
6868 
6869 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6870 			break;
6871 
6872 	repeat:
6873 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6874 			/* step marks */
6875 			int next = (last_mark+1) % SYNC_MARKS;
6876 
6877 			mddev->resync_mark = mark[next];
6878 			mddev->resync_mark_cnt = mark_cnt[next];
6879 			mark[next] = jiffies;
6880 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6881 			last_mark = next;
6882 		}
6883 
6884 
6885 		if (kthread_should_stop())
6886 			goto interrupted;
6887 
6888 
6889 		/*
6890 		 * this loop exits only if either when we are slower than
6891 		 * the 'hard' speed limit, or the system was IO-idle for
6892 		 * a jiffy.
6893 		 * the system might be non-idle CPU-wise, but we only care
6894 		 * about not overloading the IO subsystem. (things like an
6895 		 * e2fsck being done on the RAID array should execute fast)
6896 		 */
6897 		md_unplug(mddev);
6898 		cond_resched();
6899 
6900 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6901 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6902 
6903 		if (currspeed > speed_min(mddev)) {
6904 			if ((currspeed > speed_max(mddev)) ||
6905 					!is_mddev_idle(mddev, 0)) {
6906 				msleep(500);
6907 				goto repeat;
6908 			}
6909 		}
6910 	}
6911 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6912 	/*
6913 	 * this also signals 'finished resyncing' to md_stop
6914 	 */
6915  out:
6916 	md_unplug(mddev);
6917 
6918 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6919 
6920 	/* tell personality that we are finished */
6921 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6922 
6923 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6924 	    mddev->curr_resync > 2) {
6925 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6926 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6927 				if (mddev->curr_resync >= mddev->recovery_cp) {
6928 					printk(KERN_INFO
6929 					       "md: checkpointing %s of %s.\n",
6930 					       desc, mdname(mddev));
6931 					mddev->recovery_cp = mddev->curr_resync;
6932 				}
6933 			} else
6934 				mddev->recovery_cp = MaxSector;
6935 		} else {
6936 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6937 				mddev->curr_resync = MaxSector;
6938 			rcu_read_lock();
6939 			list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
6940 				if (rdev->raid_disk >= 0 &&
6941 				    mddev->delta_disks >= 0 &&
6942 				    !test_bit(Faulty, &rdev->flags) &&
6943 				    !test_bit(In_sync, &rdev->flags) &&
6944 				    rdev->recovery_offset < mddev->curr_resync)
6945 					rdev->recovery_offset = mddev->curr_resync;
6946 			rcu_read_unlock();
6947 		}
6948 	}
6949 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6950 
6951  skip:
6952 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6953 		/* We completed so min/max setting can be forgotten if used. */
6954 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6955 			mddev->resync_min = 0;
6956 		mddev->resync_max = MaxSector;
6957 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6958 		mddev->resync_min = mddev->curr_resync_completed;
6959 	mddev->curr_resync = 0;
6960 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6961 		mddev->curr_resync_completed = 0;
6962 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6963 	wake_up(&resync_wait);
6964 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6965 	md_wakeup_thread(mddev->thread);
6966 	return;
6967 
6968  interrupted:
6969 	/*
6970 	 * got a signal, exit.
6971 	 */
6972 	printk(KERN_INFO
6973 	       "md: md_do_sync() got signal ... exiting\n");
6974 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6975 	goto out;
6976 
6977 }
6978 EXPORT_SYMBOL_GPL(md_do_sync);
6979 
6980 
6981 static int remove_and_add_spares(mddev_t *mddev)
6982 {
6983 	mdk_rdev_t *rdev;
6984 	int spares = 0;
6985 
6986 	mddev->curr_resync_completed = 0;
6987 
6988 	list_for_each_entry(rdev, &mddev->disks, same_set)
6989 		if (rdev->raid_disk >= 0 &&
6990 		    !test_bit(Blocked, &rdev->flags) &&
6991 		    (test_bit(Faulty, &rdev->flags) ||
6992 		     ! test_bit(In_sync, &rdev->flags)) &&
6993 		    atomic_read(&rdev->nr_pending)==0) {
6994 			if (mddev->pers->hot_remove_disk(
6995 				    mddev, rdev->raid_disk)==0) {
6996 				char nm[20];
6997 				sprintf(nm,"rd%d", rdev->raid_disk);
6998 				sysfs_remove_link(&mddev->kobj, nm);
6999 				rdev->raid_disk = -1;
7000 			}
7001 		}
7002 
7003 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
7004 		list_for_each_entry(rdev, &mddev->disks, same_set) {
7005 			if (rdev->raid_disk >= 0 &&
7006 			    !test_bit(In_sync, &rdev->flags) &&
7007 			    !test_bit(Blocked, &rdev->flags))
7008 				spares++;
7009 			if (rdev->raid_disk < 0
7010 			    && !test_bit(Faulty, &rdev->flags)) {
7011 				rdev->recovery_offset = 0;
7012 				if (mddev->pers->
7013 				    hot_add_disk(mddev, rdev) == 0) {
7014 					char nm[20];
7015 					sprintf(nm, "rd%d", rdev->raid_disk);
7016 					if (sysfs_create_link(&mddev->kobj,
7017 							      &rdev->kobj, nm))
7018 						/* failure here is OK */;
7019 					spares++;
7020 					md_new_event(mddev);
7021 					set_bit(MD_CHANGE_DEVS, &mddev->flags);
7022 				} else
7023 					break;
7024 			}
7025 		}
7026 	}
7027 	return spares;
7028 }
7029 /*
7030  * This routine is regularly called by all per-raid-array threads to
7031  * deal with generic issues like resync and super-block update.
7032  * Raid personalities that don't have a thread (linear/raid0) do not
7033  * need this as they never do any recovery or update the superblock.
7034  *
7035  * It does not do any resync itself, but rather "forks" off other threads
7036  * to do that as needed.
7037  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7038  * "->recovery" and create a thread at ->sync_thread.
7039  * When the thread finishes it sets MD_RECOVERY_DONE
7040  * and wakeups up this thread which will reap the thread and finish up.
7041  * This thread also removes any faulty devices (with nr_pending == 0).
7042  *
7043  * The overall approach is:
7044  *  1/ if the superblock needs updating, update it.
7045  *  2/ If a recovery thread is running, don't do anything else.
7046  *  3/ If recovery has finished, clean up, possibly marking spares active.
7047  *  4/ If there are any faulty devices, remove them.
7048  *  5/ If array is degraded, try to add spares devices
7049  *  6/ If array has spares or is not in-sync, start a resync thread.
7050  */
7051 void md_check_recovery(mddev_t *mddev)
7052 {
7053 	mdk_rdev_t *rdev;
7054 
7055 
7056 	if (mddev->bitmap)
7057 		bitmap_daemon_work(mddev);
7058 
7059 	if (mddev->ro)
7060 		return;
7061 
7062 	if (signal_pending(current)) {
7063 		if (mddev->pers->sync_request && !mddev->external) {
7064 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7065 			       mdname(mddev));
7066 			mddev->safemode = 2;
7067 		}
7068 		flush_signals(current);
7069 	}
7070 
7071 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7072 		return;
7073 	if ( ! (
7074 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7075 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7076 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7077 		(mddev->external == 0 && mddev->safemode == 1) ||
7078 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7079 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7080 		))
7081 		return;
7082 
7083 	if (mddev_trylock(mddev)) {
7084 		int spares = 0;
7085 
7086 		if (mddev->ro) {
7087 			/* Only thing we do on a ro array is remove
7088 			 * failed devices.
7089 			 */
7090 			remove_and_add_spares(mddev);
7091 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7092 			goto unlock;
7093 		}
7094 
7095 		if (!mddev->external) {
7096 			int did_change = 0;
7097 			spin_lock_irq(&mddev->write_lock);
7098 			if (mddev->safemode &&
7099 			    !atomic_read(&mddev->writes_pending) &&
7100 			    !mddev->in_sync &&
7101 			    mddev->recovery_cp == MaxSector) {
7102 				mddev->in_sync = 1;
7103 				did_change = 1;
7104 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7105 			}
7106 			if (mddev->safemode == 1)
7107 				mddev->safemode = 0;
7108 			spin_unlock_irq(&mddev->write_lock);
7109 			if (did_change)
7110 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7111 		}
7112 
7113 		if (mddev->flags)
7114 			md_update_sb(mddev, 0);
7115 
7116 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7117 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7118 			/* resync/recovery still happening */
7119 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7120 			goto unlock;
7121 		}
7122 		if (mddev->sync_thread) {
7123 			/* resync has finished, collect result */
7124 			md_unregister_thread(mddev->sync_thread);
7125 			mddev->sync_thread = NULL;
7126 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7127 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7128 				/* success...*/
7129 				/* activate any spares */
7130 				if (mddev->pers->spare_active(mddev))
7131 					sysfs_notify(&mddev->kobj, NULL,
7132 						     "degraded");
7133 			}
7134 			if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7135 			    mddev->pers->finish_reshape)
7136 				mddev->pers->finish_reshape(mddev);
7137 			md_update_sb(mddev, 1);
7138 
7139 			/* if array is no-longer degraded, then any saved_raid_disk
7140 			 * information must be scrapped
7141 			 */
7142 			if (!mddev->degraded)
7143 				list_for_each_entry(rdev, &mddev->disks, same_set)
7144 					rdev->saved_raid_disk = -1;
7145 
7146 			mddev->recovery = 0;
7147 			/* flag recovery needed just to double check */
7148 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7149 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7150 			md_new_event(mddev);
7151 			goto unlock;
7152 		}
7153 		/* Set RUNNING before clearing NEEDED to avoid
7154 		 * any transients in the value of "sync_action".
7155 		 */
7156 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7157 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7158 		/* Clear some bits that don't mean anything, but
7159 		 * might be left set
7160 		 */
7161 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7162 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7163 
7164 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7165 			goto unlock;
7166 		/* no recovery is running.
7167 		 * remove any failed drives, then
7168 		 * add spares if possible.
7169 		 * Spare are also removed and re-added, to allow
7170 		 * the personality to fail the re-add.
7171 		 */
7172 
7173 		if (mddev->reshape_position != MaxSector) {
7174 			if (mddev->pers->check_reshape == NULL ||
7175 			    mddev->pers->check_reshape(mddev) != 0)
7176 				/* Cannot proceed */
7177 				goto unlock;
7178 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7179 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7180 		} else if ((spares = remove_and_add_spares(mddev))) {
7181 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7182 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7183 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7184 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7185 		} else if (mddev->recovery_cp < MaxSector) {
7186 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7187 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7188 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7189 			/* nothing to be done ... */
7190 			goto unlock;
7191 
7192 		if (mddev->pers->sync_request) {
7193 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
7194 				/* We are adding a device or devices to an array
7195 				 * which has the bitmap stored on all devices.
7196 				 * So make sure all bitmap pages get written
7197 				 */
7198 				bitmap_write_all(mddev->bitmap);
7199 			}
7200 			mddev->sync_thread = md_register_thread(md_do_sync,
7201 								mddev,
7202 								"resync");
7203 			if (!mddev->sync_thread) {
7204 				printk(KERN_ERR "%s: could not start resync"
7205 					" thread...\n",
7206 					mdname(mddev));
7207 				/* leave the spares where they are, it shouldn't hurt */
7208 				mddev->recovery = 0;
7209 			} else
7210 				md_wakeup_thread(mddev->sync_thread);
7211 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7212 			md_new_event(mddev);
7213 		}
7214 	unlock:
7215 		if (!mddev->sync_thread) {
7216 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7217 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7218 					       &mddev->recovery))
7219 				if (mddev->sysfs_action)
7220 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7221 		}
7222 		mddev_unlock(mddev);
7223 	}
7224 }
7225 
7226 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
7227 {
7228 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7229 	wait_event_timeout(rdev->blocked_wait,
7230 			   !test_bit(Blocked, &rdev->flags),
7231 			   msecs_to_jiffies(5000));
7232 	rdev_dec_pending(rdev, mddev);
7233 }
7234 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7235 
7236 static int md_notify_reboot(struct notifier_block *this,
7237 			    unsigned long code, void *x)
7238 {
7239 	struct list_head *tmp;
7240 	mddev_t *mddev;
7241 
7242 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
7243 
7244 		printk(KERN_INFO "md: stopping all md devices.\n");
7245 
7246 		for_each_mddev(mddev, tmp)
7247 			if (mddev_trylock(mddev)) {
7248 				/* Force a switch to readonly even array
7249 				 * appears to still be in use.  Hence
7250 				 * the '100'.
7251 				 */
7252 				md_set_readonly(mddev, 100);
7253 				mddev_unlock(mddev);
7254 			}
7255 		/*
7256 		 * certain more exotic SCSI devices are known to be
7257 		 * volatile wrt too early system reboots. While the
7258 		 * right place to handle this issue is the given
7259 		 * driver, we do want to have a safe RAID driver ...
7260 		 */
7261 		mdelay(1000*1);
7262 	}
7263 	return NOTIFY_DONE;
7264 }
7265 
7266 static struct notifier_block md_notifier = {
7267 	.notifier_call	= md_notify_reboot,
7268 	.next		= NULL,
7269 	.priority	= INT_MAX, /* before any real devices */
7270 };
7271 
7272 static void md_geninit(void)
7273 {
7274 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
7275 
7276 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
7277 }
7278 
7279 static int __init md_init(void)
7280 {
7281 	if (register_blkdev(MD_MAJOR, "md"))
7282 		return -1;
7283 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
7284 		unregister_blkdev(MD_MAJOR, "md");
7285 		return -1;
7286 	}
7287 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
7288 			    md_probe, NULL, NULL);
7289 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
7290 			    md_probe, NULL, NULL);
7291 
7292 	register_reboot_notifier(&md_notifier);
7293 	raid_table_header = register_sysctl_table(raid_root_table);
7294 
7295 	md_geninit();
7296 	return 0;
7297 }
7298 
7299 
7300 #ifndef MODULE
7301 
7302 /*
7303  * Searches all registered partitions for autorun RAID arrays
7304  * at boot time.
7305  */
7306 
7307 static LIST_HEAD(all_detected_devices);
7308 struct detected_devices_node {
7309 	struct list_head list;
7310 	dev_t dev;
7311 };
7312 
7313 void md_autodetect_dev(dev_t dev)
7314 {
7315 	struct detected_devices_node *node_detected_dev;
7316 
7317 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
7318 	if (node_detected_dev) {
7319 		node_detected_dev->dev = dev;
7320 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
7321 	} else {
7322 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
7323 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
7324 	}
7325 }
7326 
7327 
7328 static void autostart_arrays(int part)
7329 {
7330 	mdk_rdev_t *rdev;
7331 	struct detected_devices_node *node_detected_dev;
7332 	dev_t dev;
7333 	int i_scanned, i_passed;
7334 
7335 	i_scanned = 0;
7336 	i_passed = 0;
7337 
7338 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
7339 
7340 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
7341 		i_scanned++;
7342 		node_detected_dev = list_entry(all_detected_devices.next,
7343 					struct detected_devices_node, list);
7344 		list_del(&node_detected_dev->list);
7345 		dev = node_detected_dev->dev;
7346 		kfree(node_detected_dev);
7347 		rdev = md_import_device(dev,0, 90);
7348 		if (IS_ERR(rdev))
7349 			continue;
7350 
7351 		if (test_bit(Faulty, &rdev->flags)) {
7352 			MD_BUG();
7353 			continue;
7354 		}
7355 		set_bit(AutoDetected, &rdev->flags);
7356 		list_add(&rdev->same_set, &pending_raid_disks);
7357 		i_passed++;
7358 	}
7359 
7360 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
7361 						i_scanned, i_passed);
7362 
7363 	autorun_devices(part);
7364 }
7365 
7366 #endif /* !MODULE */
7367 
7368 static __exit void md_exit(void)
7369 {
7370 	mddev_t *mddev;
7371 	struct list_head *tmp;
7372 
7373 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
7374 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
7375 
7376 	unregister_blkdev(MD_MAJOR,"md");
7377 	unregister_blkdev(mdp_major, "mdp");
7378 	unregister_reboot_notifier(&md_notifier);
7379 	unregister_sysctl_table(raid_table_header);
7380 	remove_proc_entry("mdstat", NULL);
7381 	for_each_mddev(mddev, tmp) {
7382 		export_array(mddev);
7383 		mddev->hold_active = 0;
7384 	}
7385 }
7386 
7387 subsys_initcall(md_init);
7388 module_exit(md_exit)
7389 
7390 static int get_ro(char *buffer, struct kernel_param *kp)
7391 {
7392 	return sprintf(buffer, "%d", start_readonly);
7393 }
7394 static int set_ro(const char *val, struct kernel_param *kp)
7395 {
7396 	char *e;
7397 	int num = simple_strtoul(val, &e, 10);
7398 	if (*val && (*e == '\0' || *e == '\n')) {
7399 		start_readonly = num;
7400 		return 0;
7401 	}
7402 	return -EINVAL;
7403 }
7404 
7405 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
7406 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
7407 
7408 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
7409 
7410 EXPORT_SYMBOL(register_md_personality);
7411 EXPORT_SYMBOL(unregister_md_personality);
7412 EXPORT_SYMBOL(md_error);
7413 EXPORT_SYMBOL(md_done_sync);
7414 EXPORT_SYMBOL(md_write_start);
7415 EXPORT_SYMBOL(md_write_end);
7416 EXPORT_SYMBOL(md_register_thread);
7417 EXPORT_SYMBOL(md_unregister_thread);
7418 EXPORT_SYMBOL(md_wakeup_thread);
7419 EXPORT_SYMBOL(md_check_recovery);
7420 MODULE_LICENSE("GPL");
7421 MODULE_DESCRIPTION("MD RAID framework");
7422 MODULE_ALIAS("md");
7423 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
7424