xref: /openbmc/linux/drivers/md/md.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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/mutex.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 #ifndef MODULE
61 static void autostart_arrays(int part);
62 #endif
63 
64 static LIST_HEAD(pers_list);
65 static DEFINE_SPINLOCK(pers_lock);
66 
67 static void md_print_devices(void);
68 
69 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
70 static struct workqueue_struct *md_wq;
71 static struct workqueue_struct *md_misc_wq;
72 
73 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
74 
75 /*
76  * Default number of read corrections we'll attempt on an rdev
77  * before ejecting it from the array. We divide the read error
78  * count by 2 for every hour elapsed between read errors.
79  */
80 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
81 /*
82  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
83  * is 1000 KB/sec, so the extra system load does not show up that much.
84  * Increase it if you want to have more _guaranteed_ speed. Note that
85  * the RAID driver will use the maximum available bandwidth if the IO
86  * subsystem is idle. There is also an 'absolute maximum' reconstruction
87  * speed limit - in case reconstruction slows down your system despite
88  * idle IO detection.
89  *
90  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
91  * or /sys/block/mdX/md/sync_speed_{min,max}
92  */
93 
94 static int sysctl_speed_limit_min = 1000;
95 static int sysctl_speed_limit_max = 200000;
96 static inline int speed_min(mddev_t *mddev)
97 {
98 	return mddev->sync_speed_min ?
99 		mddev->sync_speed_min : sysctl_speed_limit_min;
100 }
101 
102 static inline int speed_max(mddev_t *mddev)
103 {
104 	return mddev->sync_speed_max ?
105 		mddev->sync_speed_max : sysctl_speed_limit_max;
106 }
107 
108 static struct ctl_table_header *raid_table_header;
109 
110 static ctl_table raid_table[] = {
111 	{
112 		.procname	= "speed_limit_min",
113 		.data		= &sysctl_speed_limit_min,
114 		.maxlen		= sizeof(int),
115 		.mode		= S_IRUGO|S_IWUSR,
116 		.proc_handler	= proc_dointvec,
117 	},
118 	{
119 		.procname	= "speed_limit_max",
120 		.data		= &sysctl_speed_limit_max,
121 		.maxlen		= sizeof(int),
122 		.mode		= S_IRUGO|S_IWUSR,
123 		.proc_handler	= proc_dointvec,
124 	},
125 	{ }
126 };
127 
128 static ctl_table raid_dir_table[] = {
129 	{
130 		.procname	= "raid",
131 		.maxlen		= 0,
132 		.mode		= S_IRUGO|S_IXUGO,
133 		.child		= raid_table,
134 	},
135 	{ }
136 };
137 
138 static ctl_table raid_root_table[] = {
139 	{
140 		.procname	= "dev",
141 		.maxlen		= 0,
142 		.mode		= 0555,
143 		.child		= raid_dir_table,
144 	},
145 	{  }
146 };
147 
148 static const struct block_device_operations md_fops;
149 
150 static int start_readonly;
151 
152 /* bio_clone_mddev
153  * like bio_clone, but with a local bio set
154  */
155 
156 static void mddev_bio_destructor(struct bio *bio)
157 {
158 	mddev_t *mddev, **mddevp;
159 
160 	mddevp = (void*)bio;
161 	mddev = mddevp[-1];
162 
163 	bio_free(bio, mddev->bio_set);
164 }
165 
166 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
167 			    mddev_t *mddev)
168 {
169 	struct bio *b;
170 	mddev_t **mddevp;
171 
172 	if (!mddev || !mddev->bio_set)
173 		return bio_alloc(gfp_mask, nr_iovecs);
174 
175 	b = bio_alloc_bioset(gfp_mask, nr_iovecs,
176 			     mddev->bio_set);
177 	if (!b)
178 		return NULL;
179 	mddevp = (void*)b;
180 	mddevp[-1] = mddev;
181 	b->bi_destructor = mddev_bio_destructor;
182 	return b;
183 }
184 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
185 
186 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
187 			    mddev_t *mddev)
188 {
189 	struct bio *b;
190 	mddev_t **mddevp;
191 
192 	if (!mddev || !mddev->bio_set)
193 		return bio_clone(bio, gfp_mask);
194 
195 	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
196 			     mddev->bio_set);
197 	if (!b)
198 		return NULL;
199 	mddevp = (void*)b;
200 	mddevp[-1] = mddev;
201 	b->bi_destructor = mddev_bio_destructor;
202 	__bio_clone(b, bio);
203 	if (bio_integrity(bio)) {
204 		int ret;
205 
206 		ret = bio_integrity_clone(b, bio, gfp_mask, mddev->bio_set);
207 
208 		if (ret < 0) {
209 			bio_put(b);
210 			return NULL;
211 		}
212 	}
213 
214 	return b;
215 }
216 EXPORT_SYMBOL_GPL(bio_clone_mddev);
217 
218 /*
219  * We have a system wide 'event count' that is incremented
220  * on any 'interesting' event, and readers of /proc/mdstat
221  * can use 'poll' or 'select' to find out when the event
222  * count increases.
223  *
224  * Events are:
225  *  start array, stop array, error, add device, remove device,
226  *  start build, activate spare
227  */
228 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
229 static atomic_t md_event_count;
230 void md_new_event(mddev_t *mddev)
231 {
232 	atomic_inc(&md_event_count);
233 	wake_up(&md_event_waiters);
234 }
235 EXPORT_SYMBOL_GPL(md_new_event);
236 
237 /* Alternate version that can be called from interrupts
238  * when calling sysfs_notify isn't needed.
239  */
240 static void md_new_event_inintr(mddev_t *mddev)
241 {
242 	atomic_inc(&md_event_count);
243 	wake_up(&md_event_waiters);
244 }
245 
246 /*
247  * Enables to iterate over all existing md arrays
248  * all_mddevs_lock protects this list.
249  */
250 static LIST_HEAD(all_mddevs);
251 static DEFINE_SPINLOCK(all_mddevs_lock);
252 
253 
254 /*
255  * iterates through all used mddevs in the system.
256  * We take care to grab the all_mddevs_lock whenever navigating
257  * the list, and to always hold a refcount when unlocked.
258  * Any code which breaks out of this loop while own
259  * a reference to the current mddev and must mddev_put it.
260  */
261 #define for_each_mddev(mddev,tmp)					\
262 									\
263 	for (({ spin_lock(&all_mddevs_lock); 				\
264 		tmp = all_mddevs.next;					\
265 		mddev = NULL;});					\
266 	     ({ if (tmp != &all_mddevs)					\
267 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
268 		spin_unlock(&all_mddevs_lock);				\
269 		if (mddev) mddev_put(mddev);				\
270 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
271 		tmp != &all_mddevs;});					\
272 	     ({ spin_lock(&all_mddevs_lock);				\
273 		tmp = tmp->next;})					\
274 		)
275 
276 
277 /* Rather than calling directly into the personality make_request function,
278  * IO requests come here first so that we can check if the device is
279  * being suspended pending a reconfiguration.
280  * We hold a refcount over the call to ->make_request.  By the time that
281  * call has finished, the bio has been linked into some internal structure
282  * and so is visible to ->quiesce(), so we don't need the refcount any more.
283  */
284 static int md_make_request(struct request_queue *q, struct bio *bio)
285 {
286 	const int rw = bio_data_dir(bio);
287 	mddev_t *mddev = q->queuedata;
288 	int rv;
289 	int cpu;
290 
291 	if (mddev == NULL || mddev->pers == NULL) {
292 		bio_io_error(bio);
293 		return 0;
294 	}
295 	rcu_read_lock();
296 	if (mddev->suspended) {
297 		DEFINE_WAIT(__wait);
298 		for (;;) {
299 			prepare_to_wait(&mddev->sb_wait, &__wait,
300 					TASK_UNINTERRUPTIBLE);
301 			if (!mddev->suspended)
302 				break;
303 			rcu_read_unlock();
304 			schedule();
305 			rcu_read_lock();
306 		}
307 		finish_wait(&mddev->sb_wait, &__wait);
308 	}
309 	atomic_inc(&mddev->active_io);
310 	rcu_read_unlock();
311 
312 	rv = mddev->pers->make_request(mddev, bio);
313 
314 	cpu = part_stat_lock();
315 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
316 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
317 		      bio_sectors(bio));
318 	part_stat_unlock();
319 
320 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
321 		wake_up(&mddev->sb_wait);
322 
323 	return rv;
324 }
325 
326 /* mddev_suspend makes sure no new requests are submitted
327  * to the device, and that any requests that have been submitted
328  * are completely handled.
329  * Once ->stop is called and completes, the module will be completely
330  * unused.
331  */
332 void mddev_suspend(mddev_t *mddev)
333 {
334 	BUG_ON(mddev->suspended);
335 	mddev->suspended = 1;
336 	synchronize_rcu();
337 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
338 	mddev->pers->quiesce(mddev, 1);
339 }
340 EXPORT_SYMBOL_GPL(mddev_suspend);
341 
342 void mddev_resume(mddev_t *mddev)
343 {
344 	mddev->suspended = 0;
345 	wake_up(&mddev->sb_wait);
346 	mddev->pers->quiesce(mddev, 0);
347 }
348 EXPORT_SYMBOL_GPL(mddev_resume);
349 
350 int mddev_congested(mddev_t *mddev, int bits)
351 {
352 	return mddev->suspended;
353 }
354 EXPORT_SYMBOL(mddev_congested);
355 
356 /*
357  * Generic flush handling for md
358  */
359 
360 static void md_end_flush(struct bio *bio, int err)
361 {
362 	mdk_rdev_t *rdev = bio->bi_private;
363 	mddev_t *mddev = rdev->mddev;
364 
365 	rdev_dec_pending(rdev, mddev);
366 
367 	if (atomic_dec_and_test(&mddev->flush_pending)) {
368 		/* The pre-request flush has finished */
369 		queue_work(md_wq, &mddev->flush_work);
370 	}
371 	bio_put(bio);
372 }
373 
374 static void md_submit_flush_data(struct work_struct *ws);
375 
376 static void submit_flushes(struct work_struct *ws)
377 {
378 	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
379 	mdk_rdev_t *rdev;
380 
381 	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
382 	atomic_set(&mddev->flush_pending, 1);
383 	rcu_read_lock();
384 	list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
385 		if (rdev->raid_disk >= 0 &&
386 		    !test_bit(Faulty, &rdev->flags)) {
387 			/* Take two references, one is dropped
388 			 * when request finishes, one after
389 			 * we reclaim rcu_read_lock
390 			 */
391 			struct bio *bi;
392 			atomic_inc(&rdev->nr_pending);
393 			atomic_inc(&rdev->nr_pending);
394 			rcu_read_unlock();
395 			bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
396 			bi->bi_end_io = md_end_flush;
397 			bi->bi_private = rdev;
398 			bi->bi_bdev = rdev->bdev;
399 			atomic_inc(&mddev->flush_pending);
400 			submit_bio(WRITE_FLUSH, bi);
401 			rcu_read_lock();
402 			rdev_dec_pending(rdev, mddev);
403 		}
404 	rcu_read_unlock();
405 	if (atomic_dec_and_test(&mddev->flush_pending))
406 		queue_work(md_wq, &mddev->flush_work);
407 }
408 
409 static void md_submit_flush_data(struct work_struct *ws)
410 {
411 	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
412 	struct bio *bio = mddev->flush_bio;
413 
414 	if (bio->bi_size == 0)
415 		/* an empty barrier - all done */
416 		bio_endio(bio, 0);
417 	else {
418 		bio->bi_rw &= ~REQ_FLUSH;
419 		if (mddev->pers->make_request(mddev, bio))
420 			generic_make_request(bio);
421 	}
422 
423 	mddev->flush_bio = NULL;
424 	wake_up(&mddev->sb_wait);
425 }
426 
427 void md_flush_request(mddev_t *mddev, struct bio *bio)
428 {
429 	spin_lock_irq(&mddev->write_lock);
430 	wait_event_lock_irq(mddev->sb_wait,
431 			    !mddev->flush_bio,
432 			    mddev->write_lock, /*nothing*/);
433 	mddev->flush_bio = bio;
434 	spin_unlock_irq(&mddev->write_lock);
435 
436 	INIT_WORK(&mddev->flush_work, submit_flushes);
437 	queue_work(md_wq, &mddev->flush_work);
438 }
439 EXPORT_SYMBOL(md_flush_request);
440 
441 /* Support for plugging.
442  * This mirrors the plugging support in request_queue, but does not
443  * require having a whole queue
444  */
445 static void plugger_work(struct work_struct *work)
446 {
447 	struct plug_handle *plug =
448 		container_of(work, struct plug_handle, unplug_work);
449 	plug->unplug_fn(plug);
450 }
451 static void plugger_timeout(unsigned long data)
452 {
453 	struct plug_handle *plug = (void *)data;
454 	kblockd_schedule_work(NULL, &plug->unplug_work);
455 }
456 void plugger_init(struct plug_handle *plug,
457 		  void (*unplug_fn)(struct plug_handle *))
458 {
459 	plug->unplug_flag = 0;
460 	plug->unplug_fn = unplug_fn;
461 	init_timer(&plug->unplug_timer);
462 	plug->unplug_timer.function = plugger_timeout;
463 	plug->unplug_timer.data = (unsigned long)plug;
464 	INIT_WORK(&plug->unplug_work, plugger_work);
465 }
466 EXPORT_SYMBOL_GPL(plugger_init);
467 
468 void plugger_set_plug(struct plug_handle *plug)
469 {
470 	if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag))
471 		mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1);
472 }
473 EXPORT_SYMBOL_GPL(plugger_set_plug);
474 
475 int plugger_remove_plug(struct plug_handle *plug)
476 {
477 	if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) {
478 		del_timer(&plug->unplug_timer);
479 		return 1;
480 	} else
481 		return 0;
482 }
483 EXPORT_SYMBOL_GPL(plugger_remove_plug);
484 
485 
486 static inline mddev_t *mddev_get(mddev_t *mddev)
487 {
488 	atomic_inc(&mddev->active);
489 	return mddev;
490 }
491 
492 static void mddev_delayed_delete(struct work_struct *ws);
493 
494 static void mddev_put(mddev_t *mddev)
495 {
496 	struct bio_set *bs = NULL;
497 
498 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
499 		return;
500 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
501 	    mddev->ctime == 0 && !mddev->hold_active) {
502 		/* Array is not configured at all, and not held active,
503 		 * so destroy it */
504 		list_del(&mddev->all_mddevs);
505 		bs = mddev->bio_set;
506 		mddev->bio_set = NULL;
507 		if (mddev->gendisk) {
508 			/* We did a probe so need to clean up.  Call
509 			 * queue_work inside the spinlock so that
510 			 * flush_workqueue() after mddev_find will
511 			 * succeed in waiting for the work to be done.
512 			 */
513 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
514 			queue_work(md_misc_wq, &mddev->del_work);
515 		} else
516 			kfree(mddev);
517 	}
518 	spin_unlock(&all_mddevs_lock);
519 	if (bs)
520 		bioset_free(bs);
521 }
522 
523 void mddev_init(mddev_t *mddev)
524 {
525 	mutex_init(&mddev->open_mutex);
526 	mutex_init(&mddev->reconfig_mutex);
527 	mutex_init(&mddev->bitmap_info.mutex);
528 	INIT_LIST_HEAD(&mddev->disks);
529 	INIT_LIST_HEAD(&mddev->all_mddevs);
530 	init_timer(&mddev->safemode_timer);
531 	atomic_set(&mddev->active, 1);
532 	atomic_set(&mddev->openers, 0);
533 	atomic_set(&mddev->active_io, 0);
534 	spin_lock_init(&mddev->write_lock);
535 	atomic_set(&mddev->flush_pending, 0);
536 	init_waitqueue_head(&mddev->sb_wait);
537 	init_waitqueue_head(&mddev->recovery_wait);
538 	mddev->reshape_position = MaxSector;
539 	mddev->resync_min = 0;
540 	mddev->resync_max = MaxSector;
541 	mddev->level = LEVEL_NONE;
542 }
543 EXPORT_SYMBOL_GPL(mddev_init);
544 
545 static mddev_t * mddev_find(dev_t unit)
546 {
547 	mddev_t *mddev, *new = NULL;
548 
549  retry:
550 	spin_lock(&all_mddevs_lock);
551 
552 	if (unit) {
553 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
554 			if (mddev->unit == unit) {
555 				mddev_get(mddev);
556 				spin_unlock(&all_mddevs_lock);
557 				kfree(new);
558 				return mddev;
559 			}
560 
561 		if (new) {
562 			list_add(&new->all_mddevs, &all_mddevs);
563 			spin_unlock(&all_mddevs_lock);
564 			new->hold_active = UNTIL_IOCTL;
565 			return new;
566 		}
567 	} else if (new) {
568 		/* find an unused unit number */
569 		static int next_minor = 512;
570 		int start = next_minor;
571 		int is_free = 0;
572 		int dev = 0;
573 		while (!is_free) {
574 			dev = MKDEV(MD_MAJOR, next_minor);
575 			next_minor++;
576 			if (next_minor > MINORMASK)
577 				next_minor = 0;
578 			if (next_minor == start) {
579 				/* Oh dear, all in use. */
580 				spin_unlock(&all_mddevs_lock);
581 				kfree(new);
582 				return NULL;
583 			}
584 
585 			is_free = 1;
586 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
587 				if (mddev->unit == dev) {
588 					is_free = 0;
589 					break;
590 				}
591 		}
592 		new->unit = dev;
593 		new->md_minor = MINOR(dev);
594 		new->hold_active = UNTIL_STOP;
595 		list_add(&new->all_mddevs, &all_mddevs);
596 		spin_unlock(&all_mddevs_lock);
597 		return new;
598 	}
599 	spin_unlock(&all_mddevs_lock);
600 
601 	new = kzalloc(sizeof(*new), GFP_KERNEL);
602 	if (!new)
603 		return NULL;
604 
605 	new->unit = unit;
606 	if (MAJOR(unit) == MD_MAJOR)
607 		new->md_minor = MINOR(unit);
608 	else
609 		new->md_minor = MINOR(unit) >> MdpMinorShift;
610 
611 	mddev_init(new);
612 
613 	goto retry;
614 }
615 
616 static inline int mddev_lock(mddev_t * mddev)
617 {
618 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
619 }
620 
621 static inline int mddev_is_locked(mddev_t *mddev)
622 {
623 	return mutex_is_locked(&mddev->reconfig_mutex);
624 }
625 
626 static inline int mddev_trylock(mddev_t * mddev)
627 {
628 	return mutex_trylock(&mddev->reconfig_mutex);
629 }
630 
631 static struct attribute_group md_redundancy_group;
632 
633 static void mddev_unlock(mddev_t * mddev)
634 {
635 	if (mddev->to_remove) {
636 		/* These cannot be removed under reconfig_mutex as
637 		 * an access to the files will try to take reconfig_mutex
638 		 * while holding the file unremovable, which leads to
639 		 * a deadlock.
640 		 * So hold set sysfs_active while the remove in happeing,
641 		 * and anything else which might set ->to_remove or my
642 		 * otherwise change the sysfs namespace will fail with
643 		 * -EBUSY if sysfs_active is still set.
644 		 * We set sysfs_active under reconfig_mutex and elsewhere
645 		 * test it under the same mutex to ensure its correct value
646 		 * is seen.
647 		 */
648 		struct attribute_group *to_remove = mddev->to_remove;
649 		mddev->to_remove = NULL;
650 		mddev->sysfs_active = 1;
651 		mutex_unlock(&mddev->reconfig_mutex);
652 
653 		if (mddev->kobj.sd) {
654 			if (to_remove != &md_redundancy_group)
655 				sysfs_remove_group(&mddev->kobj, to_remove);
656 			if (mddev->pers == NULL ||
657 			    mddev->pers->sync_request == NULL) {
658 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
659 				if (mddev->sysfs_action)
660 					sysfs_put(mddev->sysfs_action);
661 				mddev->sysfs_action = NULL;
662 			}
663 		}
664 		mddev->sysfs_active = 0;
665 	} else
666 		mutex_unlock(&mddev->reconfig_mutex);
667 
668 	md_wakeup_thread(mddev->thread);
669 }
670 
671 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
672 {
673 	mdk_rdev_t *rdev;
674 
675 	list_for_each_entry(rdev, &mddev->disks, same_set)
676 		if (rdev->desc_nr == nr)
677 			return rdev;
678 
679 	return NULL;
680 }
681 
682 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
683 {
684 	mdk_rdev_t *rdev;
685 
686 	list_for_each_entry(rdev, &mddev->disks, same_set)
687 		if (rdev->bdev->bd_dev == dev)
688 			return rdev;
689 
690 	return NULL;
691 }
692 
693 static struct mdk_personality *find_pers(int level, char *clevel)
694 {
695 	struct mdk_personality *pers;
696 	list_for_each_entry(pers, &pers_list, list) {
697 		if (level != LEVEL_NONE && pers->level == level)
698 			return pers;
699 		if (strcmp(pers->name, clevel)==0)
700 			return pers;
701 	}
702 	return NULL;
703 }
704 
705 /* return the offset of the super block in 512byte sectors */
706 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
707 {
708 	sector_t num_sectors = i_size_read(bdev->bd_inode) / 512;
709 	return MD_NEW_SIZE_SECTORS(num_sectors);
710 }
711 
712 static int alloc_disk_sb(mdk_rdev_t * rdev)
713 {
714 	if (rdev->sb_page)
715 		MD_BUG();
716 
717 	rdev->sb_page = alloc_page(GFP_KERNEL);
718 	if (!rdev->sb_page) {
719 		printk(KERN_ALERT "md: out of memory.\n");
720 		return -ENOMEM;
721 	}
722 
723 	return 0;
724 }
725 
726 static void free_disk_sb(mdk_rdev_t * rdev)
727 {
728 	if (rdev->sb_page) {
729 		put_page(rdev->sb_page);
730 		rdev->sb_loaded = 0;
731 		rdev->sb_page = NULL;
732 		rdev->sb_start = 0;
733 		rdev->sectors = 0;
734 	}
735 }
736 
737 
738 static void super_written(struct bio *bio, int error)
739 {
740 	mdk_rdev_t *rdev = bio->bi_private;
741 	mddev_t *mddev = rdev->mddev;
742 
743 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
744 		printk("md: super_written gets error=%d, uptodate=%d\n",
745 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
746 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
747 		md_error(mddev, rdev);
748 	}
749 
750 	if (atomic_dec_and_test(&mddev->pending_writes))
751 		wake_up(&mddev->sb_wait);
752 	bio_put(bio);
753 }
754 
755 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
756 		   sector_t sector, int size, struct page *page)
757 {
758 	/* write first size bytes of page to sector of rdev
759 	 * Increment mddev->pending_writes before returning
760 	 * and decrement it on completion, waking up sb_wait
761 	 * if zero is reached.
762 	 * If an error occurred, call md_error
763 	 */
764 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
765 
766 	bio->bi_bdev = rdev->bdev;
767 	bio->bi_sector = sector;
768 	bio_add_page(bio, page, size, 0);
769 	bio->bi_private = rdev;
770 	bio->bi_end_io = super_written;
771 
772 	atomic_inc(&mddev->pending_writes);
773 	submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
774 		   bio);
775 }
776 
777 void md_super_wait(mddev_t *mddev)
778 {
779 	/* wait for all superblock writes that were scheduled to complete */
780 	DEFINE_WAIT(wq);
781 	for(;;) {
782 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
783 		if (atomic_read(&mddev->pending_writes)==0)
784 			break;
785 		schedule();
786 	}
787 	finish_wait(&mddev->sb_wait, &wq);
788 }
789 
790 static void bi_complete(struct bio *bio, int error)
791 {
792 	complete((struct completion*)bio->bi_private);
793 }
794 
795 int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
796 		 struct page *page, int rw)
797 {
798 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
799 	struct completion event;
800 	int ret;
801 
802 	rw |= REQ_SYNC | REQ_UNPLUG;
803 
804 	bio->bi_bdev = rdev->bdev;
805 	bio->bi_sector = sector;
806 	bio_add_page(bio, page, size, 0);
807 	init_completion(&event);
808 	bio->bi_private = &event;
809 	bio->bi_end_io = bi_complete;
810 	submit_bio(rw, bio);
811 	wait_for_completion(&event);
812 
813 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
814 	bio_put(bio);
815 	return ret;
816 }
817 EXPORT_SYMBOL_GPL(sync_page_io);
818 
819 static int read_disk_sb(mdk_rdev_t * rdev, int size)
820 {
821 	char b[BDEVNAME_SIZE];
822 	if (!rdev->sb_page) {
823 		MD_BUG();
824 		return -EINVAL;
825 	}
826 	if (rdev->sb_loaded)
827 		return 0;
828 
829 
830 	if (!sync_page_io(rdev, rdev->sb_start, size, rdev->sb_page, READ))
831 		goto fail;
832 	rdev->sb_loaded = 1;
833 	return 0;
834 
835 fail:
836 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
837 		bdevname(rdev->bdev,b));
838 	return -EINVAL;
839 }
840 
841 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
842 {
843 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
844 		sb1->set_uuid1 == sb2->set_uuid1 &&
845 		sb1->set_uuid2 == sb2->set_uuid2 &&
846 		sb1->set_uuid3 == sb2->set_uuid3;
847 }
848 
849 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
850 {
851 	int ret;
852 	mdp_super_t *tmp1, *tmp2;
853 
854 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
855 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
856 
857 	if (!tmp1 || !tmp2) {
858 		ret = 0;
859 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
860 		goto abort;
861 	}
862 
863 	*tmp1 = *sb1;
864 	*tmp2 = *sb2;
865 
866 	/*
867 	 * nr_disks is not constant
868 	 */
869 	tmp1->nr_disks = 0;
870 	tmp2->nr_disks = 0;
871 
872 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
873 abort:
874 	kfree(tmp1);
875 	kfree(tmp2);
876 	return ret;
877 }
878 
879 
880 static u32 md_csum_fold(u32 csum)
881 {
882 	csum = (csum & 0xffff) + (csum >> 16);
883 	return (csum & 0xffff) + (csum >> 16);
884 }
885 
886 static unsigned int calc_sb_csum(mdp_super_t * sb)
887 {
888 	u64 newcsum = 0;
889 	u32 *sb32 = (u32*)sb;
890 	int i;
891 	unsigned int disk_csum, csum;
892 
893 	disk_csum = sb->sb_csum;
894 	sb->sb_csum = 0;
895 
896 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
897 		newcsum += sb32[i];
898 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
899 
900 
901 #ifdef CONFIG_ALPHA
902 	/* This used to use csum_partial, which was wrong for several
903 	 * reasons including that different results are returned on
904 	 * different architectures.  It isn't critical that we get exactly
905 	 * the same return value as before (we always csum_fold before
906 	 * testing, and that removes any differences).  However as we
907 	 * know that csum_partial always returned a 16bit value on
908 	 * alphas, do a fold to maximise conformity to previous behaviour.
909 	 */
910 	sb->sb_csum = md_csum_fold(disk_csum);
911 #else
912 	sb->sb_csum = disk_csum;
913 #endif
914 	return csum;
915 }
916 
917 
918 /*
919  * Handle superblock details.
920  * We want to be able to handle multiple superblock formats
921  * so we have a common interface to them all, and an array of
922  * different handlers.
923  * We rely on user-space to write the initial superblock, and support
924  * reading and updating of superblocks.
925  * Interface methods are:
926  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
927  *      loads and validates a superblock on dev.
928  *      if refdev != NULL, compare superblocks on both devices
929  *    Return:
930  *      0 - dev has a superblock that is compatible with refdev
931  *      1 - dev has a superblock that is compatible and newer than refdev
932  *          so dev should be used as the refdev in future
933  *     -EINVAL superblock incompatible or invalid
934  *     -othererror e.g. -EIO
935  *
936  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
937  *      Verify that dev is acceptable into mddev.
938  *       The first time, mddev->raid_disks will be 0, and data from
939  *       dev should be merged in.  Subsequent calls check that dev
940  *       is new enough.  Return 0 or -EINVAL
941  *
942  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
943  *     Update the superblock for rdev with data in mddev
944  *     This does not write to disc.
945  *
946  */
947 
948 struct super_type  {
949 	char		    *name;
950 	struct module	    *owner;
951 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
952 					  int minor_version);
953 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
954 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
955 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
956 						sector_t num_sectors);
957 };
958 
959 /*
960  * Check that the given mddev has no bitmap.
961  *
962  * This function is called from the run method of all personalities that do not
963  * support bitmaps. It prints an error message and returns non-zero if mddev
964  * has a bitmap. Otherwise, it returns 0.
965  *
966  */
967 int md_check_no_bitmap(mddev_t *mddev)
968 {
969 	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
970 		return 0;
971 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
972 		mdname(mddev), mddev->pers->name);
973 	return 1;
974 }
975 EXPORT_SYMBOL(md_check_no_bitmap);
976 
977 /*
978  * load_super for 0.90.0
979  */
980 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
981 {
982 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
983 	mdp_super_t *sb;
984 	int ret;
985 
986 	/*
987 	 * Calculate the position of the superblock (512byte sectors),
988 	 * it's at the end of the disk.
989 	 *
990 	 * It also happens to be a multiple of 4Kb.
991 	 */
992 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
993 
994 	ret = read_disk_sb(rdev, MD_SB_BYTES);
995 	if (ret) return ret;
996 
997 	ret = -EINVAL;
998 
999 	bdevname(rdev->bdev, b);
1000 	sb = (mdp_super_t*)page_address(rdev->sb_page);
1001 
1002 	if (sb->md_magic != MD_SB_MAGIC) {
1003 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
1004 		       b);
1005 		goto abort;
1006 	}
1007 
1008 	if (sb->major_version != 0 ||
1009 	    sb->minor_version < 90 ||
1010 	    sb->minor_version > 91) {
1011 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1012 			sb->major_version, sb->minor_version,
1013 			b);
1014 		goto abort;
1015 	}
1016 
1017 	if (sb->raid_disks <= 0)
1018 		goto abort;
1019 
1020 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1021 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1022 			b);
1023 		goto abort;
1024 	}
1025 
1026 	rdev->preferred_minor = sb->md_minor;
1027 	rdev->data_offset = 0;
1028 	rdev->sb_size = MD_SB_BYTES;
1029 
1030 	if (sb->level == LEVEL_MULTIPATH)
1031 		rdev->desc_nr = -1;
1032 	else
1033 		rdev->desc_nr = sb->this_disk.number;
1034 
1035 	if (!refdev) {
1036 		ret = 1;
1037 	} else {
1038 		__u64 ev1, ev2;
1039 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
1040 		if (!uuid_equal(refsb, sb)) {
1041 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
1042 				b, bdevname(refdev->bdev,b2));
1043 			goto abort;
1044 		}
1045 		if (!sb_equal(refsb, sb)) {
1046 			printk(KERN_WARNING "md: %s has same UUID"
1047 			       " but different superblock to %s\n",
1048 			       b, bdevname(refdev->bdev, b2));
1049 			goto abort;
1050 		}
1051 		ev1 = md_event(sb);
1052 		ev2 = md_event(refsb);
1053 		if (ev1 > ev2)
1054 			ret = 1;
1055 		else
1056 			ret = 0;
1057 	}
1058 	rdev->sectors = rdev->sb_start;
1059 
1060 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
1061 		/* "this cannot possibly happen" ... */
1062 		ret = -EINVAL;
1063 
1064  abort:
1065 	return ret;
1066 }
1067 
1068 /*
1069  * validate_super for 0.90.0
1070  */
1071 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1072 {
1073 	mdp_disk_t *desc;
1074 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
1075 	__u64 ev1 = md_event(sb);
1076 
1077 	rdev->raid_disk = -1;
1078 	clear_bit(Faulty, &rdev->flags);
1079 	clear_bit(In_sync, &rdev->flags);
1080 	clear_bit(WriteMostly, &rdev->flags);
1081 
1082 	if (mddev->raid_disks == 0) {
1083 		mddev->major_version = 0;
1084 		mddev->minor_version = sb->minor_version;
1085 		mddev->patch_version = sb->patch_version;
1086 		mddev->external = 0;
1087 		mddev->chunk_sectors = sb->chunk_size >> 9;
1088 		mddev->ctime = sb->ctime;
1089 		mddev->utime = sb->utime;
1090 		mddev->level = sb->level;
1091 		mddev->clevel[0] = 0;
1092 		mddev->layout = sb->layout;
1093 		mddev->raid_disks = sb->raid_disks;
1094 		mddev->dev_sectors = sb->size * 2;
1095 		mddev->events = ev1;
1096 		mddev->bitmap_info.offset = 0;
1097 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1098 
1099 		if (mddev->minor_version >= 91) {
1100 			mddev->reshape_position = sb->reshape_position;
1101 			mddev->delta_disks = sb->delta_disks;
1102 			mddev->new_level = sb->new_level;
1103 			mddev->new_layout = sb->new_layout;
1104 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1105 		} else {
1106 			mddev->reshape_position = MaxSector;
1107 			mddev->delta_disks = 0;
1108 			mddev->new_level = mddev->level;
1109 			mddev->new_layout = mddev->layout;
1110 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1111 		}
1112 
1113 		if (sb->state & (1<<MD_SB_CLEAN))
1114 			mddev->recovery_cp = MaxSector;
1115 		else {
1116 			if (sb->events_hi == sb->cp_events_hi &&
1117 				sb->events_lo == sb->cp_events_lo) {
1118 				mddev->recovery_cp = sb->recovery_cp;
1119 			} else
1120 				mddev->recovery_cp = 0;
1121 		}
1122 
1123 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1124 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1125 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1126 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1127 
1128 		mddev->max_disks = MD_SB_DISKS;
1129 
1130 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1131 		    mddev->bitmap_info.file == NULL)
1132 			mddev->bitmap_info.offset =
1133 				mddev->bitmap_info.default_offset;
1134 
1135 	} else if (mddev->pers == NULL) {
1136 		/* Insist on good event counter while assembling, except
1137 		 * for spares (which don't need an event count) */
1138 		++ev1;
1139 		if (sb->disks[rdev->desc_nr].state & (
1140 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1141 			if (ev1 < mddev->events)
1142 				return -EINVAL;
1143 	} else if (mddev->bitmap) {
1144 		/* if adding to array with a bitmap, then we can accept an
1145 		 * older device ... but not too old.
1146 		 */
1147 		if (ev1 < mddev->bitmap->events_cleared)
1148 			return 0;
1149 	} else {
1150 		if (ev1 < mddev->events)
1151 			/* just a hot-add of a new device, leave raid_disk at -1 */
1152 			return 0;
1153 	}
1154 
1155 	if (mddev->level != LEVEL_MULTIPATH) {
1156 		desc = sb->disks + rdev->desc_nr;
1157 
1158 		if (desc->state & (1<<MD_DISK_FAULTY))
1159 			set_bit(Faulty, &rdev->flags);
1160 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1161 			    desc->raid_disk < mddev->raid_disks */) {
1162 			set_bit(In_sync, &rdev->flags);
1163 			rdev->raid_disk = desc->raid_disk;
1164 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1165 			/* active but not in sync implies recovery up to
1166 			 * reshape position.  We don't know exactly where
1167 			 * that is, so set to zero for now */
1168 			if (mddev->minor_version >= 91) {
1169 				rdev->recovery_offset = 0;
1170 				rdev->raid_disk = desc->raid_disk;
1171 			}
1172 		}
1173 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1174 			set_bit(WriteMostly, &rdev->flags);
1175 	} else /* MULTIPATH are always insync */
1176 		set_bit(In_sync, &rdev->flags);
1177 	return 0;
1178 }
1179 
1180 /*
1181  * sync_super for 0.90.0
1182  */
1183 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1184 {
1185 	mdp_super_t *sb;
1186 	mdk_rdev_t *rdev2;
1187 	int next_spare = mddev->raid_disks;
1188 
1189 
1190 	/* make rdev->sb match mddev data..
1191 	 *
1192 	 * 1/ zero out disks
1193 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1194 	 * 3/ any empty disks < next_spare become removed
1195 	 *
1196 	 * disks[0] gets initialised to REMOVED because
1197 	 * we cannot be sure from other fields if it has
1198 	 * been initialised or not.
1199 	 */
1200 	int i;
1201 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1202 
1203 	rdev->sb_size = MD_SB_BYTES;
1204 
1205 	sb = (mdp_super_t*)page_address(rdev->sb_page);
1206 
1207 	memset(sb, 0, sizeof(*sb));
1208 
1209 	sb->md_magic = MD_SB_MAGIC;
1210 	sb->major_version = mddev->major_version;
1211 	sb->patch_version = mddev->patch_version;
1212 	sb->gvalid_words  = 0; /* ignored */
1213 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1214 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1215 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1216 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1217 
1218 	sb->ctime = mddev->ctime;
1219 	sb->level = mddev->level;
1220 	sb->size = mddev->dev_sectors / 2;
1221 	sb->raid_disks = mddev->raid_disks;
1222 	sb->md_minor = mddev->md_minor;
1223 	sb->not_persistent = 0;
1224 	sb->utime = mddev->utime;
1225 	sb->state = 0;
1226 	sb->events_hi = (mddev->events>>32);
1227 	sb->events_lo = (u32)mddev->events;
1228 
1229 	if (mddev->reshape_position == MaxSector)
1230 		sb->minor_version = 90;
1231 	else {
1232 		sb->minor_version = 91;
1233 		sb->reshape_position = mddev->reshape_position;
1234 		sb->new_level = mddev->new_level;
1235 		sb->delta_disks = mddev->delta_disks;
1236 		sb->new_layout = mddev->new_layout;
1237 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1238 	}
1239 	mddev->minor_version = sb->minor_version;
1240 	if (mddev->in_sync)
1241 	{
1242 		sb->recovery_cp = mddev->recovery_cp;
1243 		sb->cp_events_hi = (mddev->events>>32);
1244 		sb->cp_events_lo = (u32)mddev->events;
1245 		if (mddev->recovery_cp == MaxSector)
1246 			sb->state = (1<< MD_SB_CLEAN);
1247 	} else
1248 		sb->recovery_cp = 0;
1249 
1250 	sb->layout = mddev->layout;
1251 	sb->chunk_size = mddev->chunk_sectors << 9;
1252 
1253 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1254 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1255 
1256 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1257 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1258 		mdp_disk_t *d;
1259 		int desc_nr;
1260 		int is_active = test_bit(In_sync, &rdev2->flags);
1261 
1262 		if (rdev2->raid_disk >= 0 &&
1263 		    sb->minor_version >= 91)
1264 			/* we have nowhere to store the recovery_offset,
1265 			 * but if it is not below the reshape_position,
1266 			 * we can piggy-back on that.
1267 			 */
1268 			is_active = 1;
1269 		if (rdev2->raid_disk < 0 ||
1270 		    test_bit(Faulty, &rdev2->flags))
1271 			is_active = 0;
1272 		if (is_active)
1273 			desc_nr = rdev2->raid_disk;
1274 		else
1275 			desc_nr = next_spare++;
1276 		rdev2->desc_nr = desc_nr;
1277 		d = &sb->disks[rdev2->desc_nr];
1278 		nr_disks++;
1279 		d->number = rdev2->desc_nr;
1280 		d->major = MAJOR(rdev2->bdev->bd_dev);
1281 		d->minor = MINOR(rdev2->bdev->bd_dev);
1282 		if (is_active)
1283 			d->raid_disk = rdev2->raid_disk;
1284 		else
1285 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1286 		if (test_bit(Faulty, &rdev2->flags))
1287 			d->state = (1<<MD_DISK_FAULTY);
1288 		else if (is_active) {
1289 			d->state = (1<<MD_DISK_ACTIVE);
1290 			if (test_bit(In_sync, &rdev2->flags))
1291 				d->state |= (1<<MD_DISK_SYNC);
1292 			active++;
1293 			working++;
1294 		} else {
1295 			d->state = 0;
1296 			spare++;
1297 			working++;
1298 		}
1299 		if (test_bit(WriteMostly, &rdev2->flags))
1300 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1301 	}
1302 	/* now set the "removed" and "faulty" bits on any missing devices */
1303 	for (i=0 ; i < mddev->raid_disks ; i++) {
1304 		mdp_disk_t *d = &sb->disks[i];
1305 		if (d->state == 0 && d->number == 0) {
1306 			d->number = i;
1307 			d->raid_disk = i;
1308 			d->state = (1<<MD_DISK_REMOVED);
1309 			d->state |= (1<<MD_DISK_FAULTY);
1310 			failed++;
1311 		}
1312 	}
1313 	sb->nr_disks = nr_disks;
1314 	sb->active_disks = active;
1315 	sb->working_disks = working;
1316 	sb->failed_disks = failed;
1317 	sb->spare_disks = spare;
1318 
1319 	sb->this_disk = sb->disks[rdev->desc_nr];
1320 	sb->sb_csum = calc_sb_csum(sb);
1321 }
1322 
1323 /*
1324  * rdev_size_change for 0.90.0
1325  */
1326 static unsigned long long
1327 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1328 {
1329 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1330 		return 0; /* component must fit device */
1331 	if (rdev->mddev->bitmap_info.offset)
1332 		return 0; /* can't move bitmap */
1333 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1334 	if (!num_sectors || num_sectors > rdev->sb_start)
1335 		num_sectors = rdev->sb_start;
1336 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1337 		       rdev->sb_page);
1338 	md_super_wait(rdev->mddev);
1339 	return num_sectors;
1340 }
1341 
1342 
1343 /*
1344  * version 1 superblock
1345  */
1346 
1347 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1348 {
1349 	__le32 disk_csum;
1350 	u32 csum;
1351 	unsigned long long newcsum;
1352 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1353 	__le32 *isuper = (__le32*)sb;
1354 	int i;
1355 
1356 	disk_csum = sb->sb_csum;
1357 	sb->sb_csum = 0;
1358 	newcsum = 0;
1359 	for (i=0; size>=4; size -= 4 )
1360 		newcsum += le32_to_cpu(*isuper++);
1361 
1362 	if (size == 2)
1363 		newcsum += le16_to_cpu(*(__le16*) isuper);
1364 
1365 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1366 	sb->sb_csum = disk_csum;
1367 	return cpu_to_le32(csum);
1368 }
1369 
1370 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1371 {
1372 	struct mdp_superblock_1 *sb;
1373 	int ret;
1374 	sector_t sb_start;
1375 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1376 	int bmask;
1377 
1378 	/*
1379 	 * Calculate the position of the superblock in 512byte sectors.
1380 	 * It is always aligned to a 4K boundary and
1381 	 * depeding on minor_version, it can be:
1382 	 * 0: At least 8K, but less than 12K, from end of device
1383 	 * 1: At start of device
1384 	 * 2: 4K from start of device.
1385 	 */
1386 	switch(minor_version) {
1387 	case 0:
1388 		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1389 		sb_start -= 8*2;
1390 		sb_start &= ~(sector_t)(4*2-1);
1391 		break;
1392 	case 1:
1393 		sb_start = 0;
1394 		break;
1395 	case 2:
1396 		sb_start = 8;
1397 		break;
1398 	default:
1399 		return -EINVAL;
1400 	}
1401 	rdev->sb_start = sb_start;
1402 
1403 	/* superblock is rarely larger than 1K, but it can be larger,
1404 	 * and it is safe to read 4k, so we do that
1405 	 */
1406 	ret = read_disk_sb(rdev, 4096);
1407 	if (ret) return ret;
1408 
1409 
1410 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1411 
1412 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1413 	    sb->major_version != cpu_to_le32(1) ||
1414 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1415 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1416 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1417 		return -EINVAL;
1418 
1419 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1420 		printk("md: invalid superblock checksum on %s\n",
1421 			bdevname(rdev->bdev,b));
1422 		return -EINVAL;
1423 	}
1424 	if (le64_to_cpu(sb->data_size) < 10) {
1425 		printk("md: data_size too small on %s\n",
1426 		       bdevname(rdev->bdev,b));
1427 		return -EINVAL;
1428 	}
1429 
1430 	rdev->preferred_minor = 0xffff;
1431 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1432 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1433 
1434 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1435 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1436 	if (rdev->sb_size & bmask)
1437 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1438 
1439 	if (minor_version
1440 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1441 		return -EINVAL;
1442 
1443 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1444 		rdev->desc_nr = -1;
1445 	else
1446 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1447 
1448 	if (!refdev) {
1449 		ret = 1;
1450 	} else {
1451 		__u64 ev1, ev2;
1452 		struct mdp_superblock_1 *refsb =
1453 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1454 
1455 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1456 		    sb->level != refsb->level ||
1457 		    sb->layout != refsb->layout ||
1458 		    sb->chunksize != refsb->chunksize) {
1459 			printk(KERN_WARNING "md: %s has strangely different"
1460 				" superblock to %s\n",
1461 				bdevname(rdev->bdev,b),
1462 				bdevname(refdev->bdev,b2));
1463 			return -EINVAL;
1464 		}
1465 		ev1 = le64_to_cpu(sb->events);
1466 		ev2 = le64_to_cpu(refsb->events);
1467 
1468 		if (ev1 > ev2)
1469 			ret = 1;
1470 		else
1471 			ret = 0;
1472 	}
1473 	if (minor_version)
1474 		rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
1475 			le64_to_cpu(sb->data_offset);
1476 	else
1477 		rdev->sectors = rdev->sb_start;
1478 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1479 		return -EINVAL;
1480 	rdev->sectors = le64_to_cpu(sb->data_size);
1481 	if (le64_to_cpu(sb->size) > rdev->sectors)
1482 		return -EINVAL;
1483 	return ret;
1484 }
1485 
1486 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1487 {
1488 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1489 	__u64 ev1 = le64_to_cpu(sb->events);
1490 
1491 	rdev->raid_disk = -1;
1492 	clear_bit(Faulty, &rdev->flags);
1493 	clear_bit(In_sync, &rdev->flags);
1494 	clear_bit(WriteMostly, &rdev->flags);
1495 
1496 	if (mddev->raid_disks == 0) {
1497 		mddev->major_version = 1;
1498 		mddev->patch_version = 0;
1499 		mddev->external = 0;
1500 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1501 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1502 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1503 		mddev->level = le32_to_cpu(sb->level);
1504 		mddev->clevel[0] = 0;
1505 		mddev->layout = le32_to_cpu(sb->layout);
1506 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1507 		mddev->dev_sectors = le64_to_cpu(sb->size);
1508 		mddev->events = ev1;
1509 		mddev->bitmap_info.offset = 0;
1510 		mddev->bitmap_info.default_offset = 1024 >> 9;
1511 
1512 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1513 		memcpy(mddev->uuid, sb->set_uuid, 16);
1514 
1515 		mddev->max_disks =  (4096-256)/2;
1516 
1517 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1518 		    mddev->bitmap_info.file == NULL )
1519 			mddev->bitmap_info.offset =
1520 				(__s32)le32_to_cpu(sb->bitmap_offset);
1521 
1522 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1523 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1524 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1525 			mddev->new_level = le32_to_cpu(sb->new_level);
1526 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1527 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1528 		} else {
1529 			mddev->reshape_position = MaxSector;
1530 			mddev->delta_disks = 0;
1531 			mddev->new_level = mddev->level;
1532 			mddev->new_layout = mddev->layout;
1533 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1534 		}
1535 
1536 	} else if (mddev->pers == NULL) {
1537 		/* Insist of good event counter while assembling, except for
1538 		 * spares (which don't need an event count) */
1539 		++ev1;
1540 		if (rdev->desc_nr >= 0 &&
1541 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1542 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1543 			if (ev1 < mddev->events)
1544 				return -EINVAL;
1545 	} else if (mddev->bitmap) {
1546 		/* If adding to array with a bitmap, then we can accept an
1547 		 * older device, but not too old.
1548 		 */
1549 		if (ev1 < mddev->bitmap->events_cleared)
1550 			return 0;
1551 	} else {
1552 		if (ev1 < mddev->events)
1553 			/* just a hot-add of a new device, leave raid_disk at -1 */
1554 			return 0;
1555 	}
1556 	if (mddev->level != LEVEL_MULTIPATH) {
1557 		int role;
1558 		if (rdev->desc_nr < 0 ||
1559 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1560 			role = 0xffff;
1561 			rdev->desc_nr = -1;
1562 		} else
1563 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1564 		switch(role) {
1565 		case 0xffff: /* spare */
1566 			break;
1567 		case 0xfffe: /* faulty */
1568 			set_bit(Faulty, &rdev->flags);
1569 			break;
1570 		default:
1571 			if ((le32_to_cpu(sb->feature_map) &
1572 			     MD_FEATURE_RECOVERY_OFFSET))
1573 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1574 			else
1575 				set_bit(In_sync, &rdev->flags);
1576 			rdev->raid_disk = role;
1577 			break;
1578 		}
1579 		if (sb->devflags & WriteMostly1)
1580 			set_bit(WriteMostly, &rdev->flags);
1581 	} else /* MULTIPATH are always insync */
1582 		set_bit(In_sync, &rdev->flags);
1583 
1584 	return 0;
1585 }
1586 
1587 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1588 {
1589 	struct mdp_superblock_1 *sb;
1590 	mdk_rdev_t *rdev2;
1591 	int max_dev, i;
1592 	/* make rdev->sb match mddev and rdev data. */
1593 
1594 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1595 
1596 	sb->feature_map = 0;
1597 	sb->pad0 = 0;
1598 	sb->recovery_offset = cpu_to_le64(0);
1599 	memset(sb->pad1, 0, sizeof(sb->pad1));
1600 	memset(sb->pad2, 0, sizeof(sb->pad2));
1601 	memset(sb->pad3, 0, sizeof(sb->pad3));
1602 
1603 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1604 	sb->events = cpu_to_le64(mddev->events);
1605 	if (mddev->in_sync)
1606 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1607 	else
1608 		sb->resync_offset = cpu_to_le64(0);
1609 
1610 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1611 
1612 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1613 	sb->size = cpu_to_le64(mddev->dev_sectors);
1614 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1615 	sb->level = cpu_to_le32(mddev->level);
1616 	sb->layout = cpu_to_le32(mddev->layout);
1617 
1618 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1619 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1620 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1621 	}
1622 
1623 	if (rdev->raid_disk >= 0 &&
1624 	    !test_bit(In_sync, &rdev->flags)) {
1625 		sb->feature_map |=
1626 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1627 		sb->recovery_offset =
1628 			cpu_to_le64(rdev->recovery_offset);
1629 	}
1630 
1631 	if (mddev->reshape_position != MaxSector) {
1632 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1633 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1634 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1635 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1636 		sb->new_level = cpu_to_le32(mddev->new_level);
1637 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1638 	}
1639 
1640 	max_dev = 0;
1641 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1642 		if (rdev2->desc_nr+1 > max_dev)
1643 			max_dev = rdev2->desc_nr+1;
1644 
1645 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1646 		int bmask;
1647 		sb->max_dev = cpu_to_le32(max_dev);
1648 		rdev->sb_size = max_dev * 2 + 256;
1649 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1650 		if (rdev->sb_size & bmask)
1651 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1652 	} else
1653 		max_dev = le32_to_cpu(sb->max_dev);
1654 
1655 	for (i=0; i<max_dev;i++)
1656 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1657 
1658 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1659 		i = rdev2->desc_nr;
1660 		if (test_bit(Faulty, &rdev2->flags))
1661 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1662 		else if (test_bit(In_sync, &rdev2->flags))
1663 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1664 		else if (rdev2->raid_disk >= 0)
1665 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1666 		else
1667 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1668 	}
1669 
1670 	sb->sb_csum = calc_sb_1_csum(sb);
1671 }
1672 
1673 static unsigned long long
1674 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1675 {
1676 	struct mdp_superblock_1 *sb;
1677 	sector_t max_sectors;
1678 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1679 		return 0; /* component must fit device */
1680 	if (rdev->sb_start < rdev->data_offset) {
1681 		/* minor versions 1 and 2; superblock before data */
1682 		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1683 		max_sectors -= rdev->data_offset;
1684 		if (!num_sectors || num_sectors > max_sectors)
1685 			num_sectors = max_sectors;
1686 	} else if (rdev->mddev->bitmap_info.offset) {
1687 		/* minor version 0 with bitmap we can't move */
1688 		return 0;
1689 	} else {
1690 		/* minor version 0; superblock after data */
1691 		sector_t sb_start;
1692 		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1693 		sb_start &= ~(sector_t)(4*2 - 1);
1694 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1695 		if (!num_sectors || num_sectors > max_sectors)
1696 			num_sectors = max_sectors;
1697 		rdev->sb_start = sb_start;
1698 	}
1699 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1700 	sb->data_size = cpu_to_le64(num_sectors);
1701 	sb->super_offset = rdev->sb_start;
1702 	sb->sb_csum = calc_sb_1_csum(sb);
1703 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1704 		       rdev->sb_page);
1705 	md_super_wait(rdev->mddev);
1706 	return num_sectors;
1707 }
1708 
1709 static struct super_type super_types[] = {
1710 	[0] = {
1711 		.name	= "0.90.0",
1712 		.owner	= THIS_MODULE,
1713 		.load_super	    = super_90_load,
1714 		.validate_super	    = super_90_validate,
1715 		.sync_super	    = super_90_sync,
1716 		.rdev_size_change   = super_90_rdev_size_change,
1717 	},
1718 	[1] = {
1719 		.name	= "md-1",
1720 		.owner	= THIS_MODULE,
1721 		.load_super	    = super_1_load,
1722 		.validate_super	    = super_1_validate,
1723 		.sync_super	    = super_1_sync,
1724 		.rdev_size_change   = super_1_rdev_size_change,
1725 	},
1726 };
1727 
1728 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1729 {
1730 	mdk_rdev_t *rdev, *rdev2;
1731 
1732 	rcu_read_lock();
1733 	rdev_for_each_rcu(rdev, mddev1)
1734 		rdev_for_each_rcu(rdev2, mddev2)
1735 			if (rdev->bdev->bd_contains ==
1736 			    rdev2->bdev->bd_contains) {
1737 				rcu_read_unlock();
1738 				return 1;
1739 			}
1740 	rcu_read_unlock();
1741 	return 0;
1742 }
1743 
1744 static LIST_HEAD(pending_raid_disks);
1745 
1746 /*
1747  * Try to register data integrity profile for an mddev
1748  *
1749  * This is called when an array is started and after a disk has been kicked
1750  * from the array. It only succeeds if all working and active component devices
1751  * are integrity capable with matching profiles.
1752  */
1753 int md_integrity_register(mddev_t *mddev)
1754 {
1755 	mdk_rdev_t *rdev, *reference = NULL;
1756 
1757 	if (list_empty(&mddev->disks))
1758 		return 0; /* nothing to do */
1759 	if (blk_get_integrity(mddev->gendisk))
1760 		return 0; /* already registered */
1761 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1762 		/* skip spares and non-functional disks */
1763 		if (test_bit(Faulty, &rdev->flags))
1764 			continue;
1765 		if (rdev->raid_disk < 0)
1766 			continue;
1767 		/*
1768 		 * If at least one rdev is not integrity capable, we can not
1769 		 * enable data integrity for the md device.
1770 		 */
1771 		if (!bdev_get_integrity(rdev->bdev))
1772 			return -EINVAL;
1773 		if (!reference) {
1774 			/* Use the first rdev as the reference */
1775 			reference = rdev;
1776 			continue;
1777 		}
1778 		/* does this rdev's profile match the reference profile? */
1779 		if (blk_integrity_compare(reference->bdev->bd_disk,
1780 				rdev->bdev->bd_disk) < 0)
1781 			return -EINVAL;
1782 	}
1783 	/*
1784 	 * All component devices are integrity capable and have matching
1785 	 * profiles, register the common profile for the md device.
1786 	 */
1787 	if (blk_integrity_register(mddev->gendisk,
1788 			bdev_get_integrity(reference->bdev)) != 0) {
1789 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1790 			mdname(mddev));
1791 		return -EINVAL;
1792 	}
1793 	printk(KERN_NOTICE "md: data integrity on %s enabled\n",
1794 		mdname(mddev));
1795 	return 0;
1796 }
1797 EXPORT_SYMBOL(md_integrity_register);
1798 
1799 /* Disable data integrity if non-capable/non-matching disk is being added */
1800 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1801 {
1802 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1803 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1804 
1805 	if (!bi_mddev) /* nothing to do */
1806 		return;
1807 	if (rdev->raid_disk < 0) /* skip spares */
1808 		return;
1809 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1810 					     rdev->bdev->bd_disk) >= 0)
1811 		return;
1812 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1813 	blk_integrity_unregister(mddev->gendisk);
1814 }
1815 EXPORT_SYMBOL(md_integrity_add_rdev);
1816 
1817 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1818 {
1819 	char b[BDEVNAME_SIZE];
1820 	struct kobject *ko;
1821 	char *s;
1822 	int err;
1823 
1824 	if (rdev->mddev) {
1825 		MD_BUG();
1826 		return -EINVAL;
1827 	}
1828 
1829 	/* prevent duplicates */
1830 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1831 		return -EEXIST;
1832 
1833 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
1834 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
1835 			rdev->sectors < mddev->dev_sectors)) {
1836 		if (mddev->pers) {
1837 			/* Cannot change size, so fail
1838 			 * If mddev->level <= 0, then we don't care
1839 			 * about aligning sizes (e.g. linear)
1840 			 */
1841 			if (mddev->level > 0)
1842 				return -ENOSPC;
1843 		} else
1844 			mddev->dev_sectors = rdev->sectors;
1845 	}
1846 
1847 	/* Verify rdev->desc_nr is unique.
1848 	 * If it is -1, assign a free number, else
1849 	 * check number is not in use
1850 	 */
1851 	if (rdev->desc_nr < 0) {
1852 		int choice = 0;
1853 		if (mddev->pers) choice = mddev->raid_disks;
1854 		while (find_rdev_nr(mddev, choice))
1855 			choice++;
1856 		rdev->desc_nr = choice;
1857 	} else {
1858 		if (find_rdev_nr(mddev, rdev->desc_nr))
1859 			return -EBUSY;
1860 	}
1861 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1862 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1863 		       mdname(mddev), mddev->max_disks);
1864 		return -EBUSY;
1865 	}
1866 	bdevname(rdev->bdev,b);
1867 	while ( (s=strchr(b, '/')) != NULL)
1868 		*s = '!';
1869 
1870 	rdev->mddev = mddev;
1871 	printk(KERN_INFO "md: bind<%s>\n", b);
1872 
1873 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1874 		goto fail;
1875 
1876 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1877 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
1878 		/* failure here is OK */;
1879 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
1880 
1881 	list_add_rcu(&rdev->same_set, &mddev->disks);
1882 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1883 
1884 	/* May as well allow recovery to be retried once */
1885 	mddev->recovery_disabled = 0;
1886 
1887 	return 0;
1888 
1889  fail:
1890 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1891 	       b, mdname(mddev));
1892 	return err;
1893 }
1894 
1895 static void md_delayed_delete(struct work_struct *ws)
1896 {
1897 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1898 	kobject_del(&rdev->kobj);
1899 	kobject_put(&rdev->kobj);
1900 }
1901 
1902 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1903 {
1904 	char b[BDEVNAME_SIZE];
1905 	if (!rdev->mddev) {
1906 		MD_BUG();
1907 		return;
1908 	}
1909 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1910 	list_del_rcu(&rdev->same_set);
1911 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1912 	rdev->mddev = NULL;
1913 	sysfs_remove_link(&rdev->kobj, "block");
1914 	sysfs_put(rdev->sysfs_state);
1915 	rdev->sysfs_state = NULL;
1916 	/* We need to delay this, otherwise we can deadlock when
1917 	 * writing to 'remove' to "dev/state".  We also need
1918 	 * to delay it due to rcu usage.
1919 	 */
1920 	synchronize_rcu();
1921 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1922 	kobject_get(&rdev->kobj);
1923 	queue_work(md_misc_wq, &rdev->del_work);
1924 }
1925 
1926 /*
1927  * prevent the device from being mounted, repartitioned or
1928  * otherwise reused by a RAID array (or any other kernel
1929  * subsystem), by bd_claiming the device.
1930  */
1931 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1932 {
1933 	int err = 0;
1934 	struct block_device *bdev;
1935 	char b[BDEVNAME_SIZE];
1936 
1937 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1938 	if (IS_ERR(bdev)) {
1939 		printk(KERN_ERR "md: could not open %s.\n",
1940 			__bdevname(dev, b));
1941 		return PTR_ERR(bdev);
1942 	}
1943 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1944 	if (err) {
1945 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1946 			bdevname(bdev, b));
1947 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1948 		return err;
1949 	}
1950 	if (!shared)
1951 		set_bit(AllReserved, &rdev->flags);
1952 	rdev->bdev = bdev;
1953 	return err;
1954 }
1955 
1956 static void unlock_rdev(mdk_rdev_t *rdev)
1957 {
1958 	struct block_device *bdev = rdev->bdev;
1959 	rdev->bdev = NULL;
1960 	if (!bdev)
1961 		MD_BUG();
1962 	bd_release(bdev);
1963 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1964 }
1965 
1966 void md_autodetect_dev(dev_t dev);
1967 
1968 static void export_rdev(mdk_rdev_t * rdev)
1969 {
1970 	char b[BDEVNAME_SIZE];
1971 	printk(KERN_INFO "md: export_rdev(%s)\n",
1972 		bdevname(rdev->bdev,b));
1973 	if (rdev->mddev)
1974 		MD_BUG();
1975 	free_disk_sb(rdev);
1976 #ifndef MODULE
1977 	if (test_bit(AutoDetected, &rdev->flags))
1978 		md_autodetect_dev(rdev->bdev->bd_dev);
1979 #endif
1980 	unlock_rdev(rdev);
1981 	kobject_put(&rdev->kobj);
1982 }
1983 
1984 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1985 {
1986 	unbind_rdev_from_array(rdev);
1987 	export_rdev(rdev);
1988 }
1989 
1990 static void export_array(mddev_t *mddev)
1991 {
1992 	mdk_rdev_t *rdev, *tmp;
1993 
1994 	rdev_for_each(rdev, tmp, mddev) {
1995 		if (!rdev->mddev) {
1996 			MD_BUG();
1997 			continue;
1998 		}
1999 		kick_rdev_from_array(rdev);
2000 	}
2001 	if (!list_empty(&mddev->disks))
2002 		MD_BUG();
2003 	mddev->raid_disks = 0;
2004 	mddev->major_version = 0;
2005 }
2006 
2007 static void print_desc(mdp_disk_t *desc)
2008 {
2009 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2010 		desc->major,desc->minor,desc->raid_disk,desc->state);
2011 }
2012 
2013 static void print_sb_90(mdp_super_t *sb)
2014 {
2015 	int i;
2016 
2017 	printk(KERN_INFO
2018 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2019 		sb->major_version, sb->minor_version, sb->patch_version,
2020 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2021 		sb->ctime);
2022 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2023 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2024 		sb->md_minor, sb->layout, sb->chunk_size);
2025 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2026 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2027 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2028 		sb->failed_disks, sb->spare_disks,
2029 		sb->sb_csum, (unsigned long)sb->events_lo);
2030 
2031 	printk(KERN_INFO);
2032 	for (i = 0; i < MD_SB_DISKS; i++) {
2033 		mdp_disk_t *desc;
2034 
2035 		desc = sb->disks + i;
2036 		if (desc->number || desc->major || desc->minor ||
2037 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2038 			printk("     D %2d: ", i);
2039 			print_desc(desc);
2040 		}
2041 	}
2042 	printk(KERN_INFO "md:     THIS: ");
2043 	print_desc(&sb->this_disk);
2044 }
2045 
2046 static void print_sb_1(struct mdp_superblock_1 *sb)
2047 {
2048 	__u8 *uuid;
2049 
2050 	uuid = sb->set_uuid;
2051 	printk(KERN_INFO
2052 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2053 	       "md:    Name: \"%s\" CT:%llu\n",
2054 		le32_to_cpu(sb->major_version),
2055 		le32_to_cpu(sb->feature_map),
2056 		uuid,
2057 		sb->set_name,
2058 		(unsigned long long)le64_to_cpu(sb->ctime)
2059 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2060 
2061 	uuid = sb->device_uuid;
2062 	printk(KERN_INFO
2063 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2064 			" RO:%llu\n"
2065 	       "md:     Dev:%08x UUID: %pU\n"
2066 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2067 	       "md:         (MaxDev:%u) \n",
2068 		le32_to_cpu(sb->level),
2069 		(unsigned long long)le64_to_cpu(sb->size),
2070 		le32_to_cpu(sb->raid_disks),
2071 		le32_to_cpu(sb->layout),
2072 		le32_to_cpu(sb->chunksize),
2073 		(unsigned long long)le64_to_cpu(sb->data_offset),
2074 		(unsigned long long)le64_to_cpu(sb->data_size),
2075 		(unsigned long long)le64_to_cpu(sb->super_offset),
2076 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2077 		le32_to_cpu(sb->dev_number),
2078 		uuid,
2079 		sb->devflags,
2080 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2081 		(unsigned long long)le64_to_cpu(sb->events),
2082 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2083 		le32_to_cpu(sb->sb_csum),
2084 		le32_to_cpu(sb->max_dev)
2085 		);
2086 }
2087 
2088 static void print_rdev(mdk_rdev_t *rdev, int major_version)
2089 {
2090 	char b[BDEVNAME_SIZE];
2091 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2092 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2093 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2094 	        rdev->desc_nr);
2095 	if (rdev->sb_loaded) {
2096 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2097 		switch (major_version) {
2098 		case 0:
2099 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
2100 			break;
2101 		case 1:
2102 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
2103 			break;
2104 		}
2105 	} else
2106 		printk(KERN_INFO "md: no rdev superblock!\n");
2107 }
2108 
2109 static void md_print_devices(void)
2110 {
2111 	struct list_head *tmp;
2112 	mdk_rdev_t *rdev;
2113 	mddev_t *mddev;
2114 	char b[BDEVNAME_SIZE];
2115 
2116 	printk("\n");
2117 	printk("md:	**********************************\n");
2118 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2119 	printk("md:	**********************************\n");
2120 	for_each_mddev(mddev, tmp) {
2121 
2122 		if (mddev->bitmap)
2123 			bitmap_print_sb(mddev->bitmap);
2124 		else
2125 			printk("%s: ", mdname(mddev));
2126 		list_for_each_entry(rdev, &mddev->disks, same_set)
2127 			printk("<%s>", bdevname(rdev->bdev,b));
2128 		printk("\n");
2129 
2130 		list_for_each_entry(rdev, &mddev->disks, same_set)
2131 			print_rdev(rdev, mddev->major_version);
2132 	}
2133 	printk("md:	**********************************\n");
2134 	printk("\n");
2135 }
2136 
2137 
2138 static void sync_sbs(mddev_t * mddev, int nospares)
2139 {
2140 	/* Update each superblock (in-memory image), but
2141 	 * if we are allowed to, skip spares which already
2142 	 * have the right event counter, or have one earlier
2143 	 * (which would mean they aren't being marked as dirty
2144 	 * with the rest of the array)
2145 	 */
2146 	mdk_rdev_t *rdev;
2147 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2148 		if (rdev->sb_events == mddev->events ||
2149 		    (nospares &&
2150 		     rdev->raid_disk < 0 &&
2151 		     rdev->sb_events+1 == mddev->events)) {
2152 			/* Don't update this superblock */
2153 			rdev->sb_loaded = 2;
2154 		} else {
2155 			super_types[mddev->major_version].
2156 				sync_super(mddev, rdev);
2157 			rdev->sb_loaded = 1;
2158 		}
2159 	}
2160 }
2161 
2162 static void md_update_sb(mddev_t * mddev, int force_change)
2163 {
2164 	mdk_rdev_t *rdev;
2165 	int sync_req;
2166 	int nospares = 0;
2167 
2168 repeat:
2169 	/* First make sure individual recovery_offsets are correct */
2170 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2171 		if (rdev->raid_disk >= 0 &&
2172 		    mddev->delta_disks >= 0 &&
2173 		    !test_bit(In_sync, &rdev->flags) &&
2174 		    mddev->curr_resync_completed > rdev->recovery_offset)
2175 				rdev->recovery_offset = mddev->curr_resync_completed;
2176 
2177 	}
2178 	if (!mddev->persistent) {
2179 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2180 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2181 		if (!mddev->external)
2182 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2183 		wake_up(&mddev->sb_wait);
2184 		return;
2185 	}
2186 
2187 	spin_lock_irq(&mddev->write_lock);
2188 
2189 	mddev->utime = get_seconds();
2190 
2191 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2192 		force_change = 1;
2193 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2194 		/* just a clean<-> dirty transition, possibly leave spares alone,
2195 		 * though if events isn't the right even/odd, we will have to do
2196 		 * spares after all
2197 		 */
2198 		nospares = 1;
2199 	if (force_change)
2200 		nospares = 0;
2201 	if (mddev->degraded)
2202 		/* If the array is degraded, then skipping spares is both
2203 		 * dangerous and fairly pointless.
2204 		 * Dangerous because a device that was removed from the array
2205 		 * might have a event_count that still looks up-to-date,
2206 		 * so it can be re-added without a resync.
2207 		 * Pointless because if there are any spares to skip,
2208 		 * then a recovery will happen and soon that array won't
2209 		 * be degraded any more and the spare can go back to sleep then.
2210 		 */
2211 		nospares = 0;
2212 
2213 	sync_req = mddev->in_sync;
2214 
2215 	/* If this is just a dirty<->clean transition, and the array is clean
2216 	 * and 'events' is odd, we can roll back to the previous clean state */
2217 	if (nospares
2218 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2219 	    && mddev->can_decrease_events
2220 	    && mddev->events != 1) {
2221 		mddev->events--;
2222 		mddev->can_decrease_events = 0;
2223 	} else {
2224 		/* otherwise we have to go forward and ... */
2225 		mddev->events ++;
2226 		mddev->can_decrease_events = nospares;
2227 	}
2228 
2229 	if (!mddev->events) {
2230 		/*
2231 		 * oops, this 64-bit counter should never wrap.
2232 		 * Either we are in around ~1 trillion A.C., assuming
2233 		 * 1 reboot per second, or we have a bug:
2234 		 */
2235 		MD_BUG();
2236 		mddev->events --;
2237 	}
2238 	sync_sbs(mddev, nospares);
2239 	spin_unlock_irq(&mddev->write_lock);
2240 
2241 	dprintk(KERN_INFO
2242 		"md: updating %s RAID superblock on device (in sync %d)\n",
2243 		mdname(mddev),mddev->in_sync);
2244 
2245 	bitmap_update_sb(mddev->bitmap);
2246 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2247 		char b[BDEVNAME_SIZE];
2248 		dprintk(KERN_INFO "md: ");
2249 		if (rdev->sb_loaded != 1)
2250 			continue; /* no noise on spare devices */
2251 		if (test_bit(Faulty, &rdev->flags))
2252 			dprintk("(skipping faulty ");
2253 
2254 		dprintk("%s ", bdevname(rdev->bdev,b));
2255 		if (!test_bit(Faulty, &rdev->flags)) {
2256 			md_super_write(mddev,rdev,
2257 				       rdev->sb_start, rdev->sb_size,
2258 				       rdev->sb_page);
2259 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2260 				bdevname(rdev->bdev,b),
2261 				(unsigned long long)rdev->sb_start);
2262 			rdev->sb_events = mddev->events;
2263 
2264 		} else
2265 			dprintk(")\n");
2266 		if (mddev->level == LEVEL_MULTIPATH)
2267 			/* only need to write one superblock... */
2268 			break;
2269 	}
2270 	md_super_wait(mddev);
2271 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2272 
2273 	spin_lock_irq(&mddev->write_lock);
2274 	if (mddev->in_sync != sync_req ||
2275 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2276 		/* have to write it out again */
2277 		spin_unlock_irq(&mddev->write_lock);
2278 		goto repeat;
2279 	}
2280 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2281 	spin_unlock_irq(&mddev->write_lock);
2282 	wake_up(&mddev->sb_wait);
2283 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2284 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2285 
2286 }
2287 
2288 /* words written to sysfs files may, or may not, be \n terminated.
2289  * We want to accept with case. For this we use cmd_match.
2290  */
2291 static int cmd_match(const char *cmd, const char *str)
2292 {
2293 	/* See if cmd, written into a sysfs file, matches
2294 	 * str.  They must either be the same, or cmd can
2295 	 * have a trailing newline
2296 	 */
2297 	while (*cmd && *str && *cmd == *str) {
2298 		cmd++;
2299 		str++;
2300 	}
2301 	if (*cmd == '\n')
2302 		cmd++;
2303 	if (*str || *cmd)
2304 		return 0;
2305 	return 1;
2306 }
2307 
2308 struct rdev_sysfs_entry {
2309 	struct attribute attr;
2310 	ssize_t (*show)(mdk_rdev_t *, char *);
2311 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2312 };
2313 
2314 static ssize_t
2315 state_show(mdk_rdev_t *rdev, char *page)
2316 {
2317 	char *sep = "";
2318 	size_t len = 0;
2319 
2320 	if (test_bit(Faulty, &rdev->flags)) {
2321 		len+= sprintf(page+len, "%sfaulty",sep);
2322 		sep = ",";
2323 	}
2324 	if (test_bit(In_sync, &rdev->flags)) {
2325 		len += sprintf(page+len, "%sin_sync",sep);
2326 		sep = ",";
2327 	}
2328 	if (test_bit(WriteMostly, &rdev->flags)) {
2329 		len += sprintf(page+len, "%swrite_mostly",sep);
2330 		sep = ",";
2331 	}
2332 	if (test_bit(Blocked, &rdev->flags)) {
2333 		len += sprintf(page+len, "%sblocked", sep);
2334 		sep = ",";
2335 	}
2336 	if (!test_bit(Faulty, &rdev->flags) &&
2337 	    !test_bit(In_sync, &rdev->flags)) {
2338 		len += sprintf(page+len, "%sspare", sep);
2339 		sep = ",";
2340 	}
2341 	return len+sprintf(page+len, "\n");
2342 }
2343 
2344 static ssize_t
2345 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2346 {
2347 	/* can write
2348 	 *  faulty  - simulates and error
2349 	 *  remove  - disconnects the device
2350 	 *  writemostly - sets write_mostly
2351 	 *  -writemostly - clears write_mostly
2352 	 *  blocked - sets the Blocked flag
2353 	 *  -blocked - clears the Blocked flag
2354 	 *  insync - sets Insync providing device isn't active
2355 	 */
2356 	int err = -EINVAL;
2357 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2358 		md_error(rdev->mddev, rdev);
2359 		err = 0;
2360 	} else if (cmd_match(buf, "remove")) {
2361 		if (rdev->raid_disk >= 0)
2362 			err = -EBUSY;
2363 		else {
2364 			mddev_t *mddev = rdev->mddev;
2365 			kick_rdev_from_array(rdev);
2366 			if (mddev->pers)
2367 				md_update_sb(mddev, 1);
2368 			md_new_event(mddev);
2369 			err = 0;
2370 		}
2371 	} else if (cmd_match(buf, "writemostly")) {
2372 		set_bit(WriteMostly, &rdev->flags);
2373 		err = 0;
2374 	} else if (cmd_match(buf, "-writemostly")) {
2375 		clear_bit(WriteMostly, &rdev->flags);
2376 		err = 0;
2377 	} else if (cmd_match(buf, "blocked")) {
2378 		set_bit(Blocked, &rdev->flags);
2379 		err = 0;
2380 	} else if (cmd_match(buf, "-blocked")) {
2381 		clear_bit(Blocked, &rdev->flags);
2382 		wake_up(&rdev->blocked_wait);
2383 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2384 		md_wakeup_thread(rdev->mddev->thread);
2385 
2386 		err = 0;
2387 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2388 		set_bit(In_sync, &rdev->flags);
2389 		err = 0;
2390 	}
2391 	if (!err)
2392 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2393 	return err ? err : len;
2394 }
2395 static struct rdev_sysfs_entry rdev_state =
2396 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2397 
2398 static ssize_t
2399 errors_show(mdk_rdev_t *rdev, char *page)
2400 {
2401 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2402 }
2403 
2404 static ssize_t
2405 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2406 {
2407 	char *e;
2408 	unsigned long n = simple_strtoul(buf, &e, 10);
2409 	if (*buf && (*e == 0 || *e == '\n')) {
2410 		atomic_set(&rdev->corrected_errors, n);
2411 		return len;
2412 	}
2413 	return -EINVAL;
2414 }
2415 static struct rdev_sysfs_entry rdev_errors =
2416 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2417 
2418 static ssize_t
2419 slot_show(mdk_rdev_t *rdev, char *page)
2420 {
2421 	if (rdev->raid_disk < 0)
2422 		return sprintf(page, "none\n");
2423 	else
2424 		return sprintf(page, "%d\n", rdev->raid_disk);
2425 }
2426 
2427 static ssize_t
2428 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2429 {
2430 	char *e;
2431 	int err;
2432 	char nm[20];
2433 	int slot = simple_strtoul(buf, &e, 10);
2434 	if (strncmp(buf, "none", 4)==0)
2435 		slot = -1;
2436 	else if (e==buf || (*e && *e!= '\n'))
2437 		return -EINVAL;
2438 	if (rdev->mddev->pers && slot == -1) {
2439 		/* Setting 'slot' on an active array requires also
2440 		 * updating the 'rd%d' link, and communicating
2441 		 * with the personality with ->hot_*_disk.
2442 		 * For now we only support removing
2443 		 * failed/spare devices.  This normally happens automatically,
2444 		 * but not when the metadata is externally managed.
2445 		 */
2446 		if (rdev->raid_disk == -1)
2447 			return -EEXIST;
2448 		/* personality does all needed checks */
2449 		if (rdev->mddev->pers->hot_add_disk == NULL)
2450 			return -EINVAL;
2451 		err = rdev->mddev->pers->
2452 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2453 		if (err)
2454 			return err;
2455 		sprintf(nm, "rd%d", rdev->raid_disk);
2456 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2457 		rdev->raid_disk = -1;
2458 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2459 		md_wakeup_thread(rdev->mddev->thread);
2460 	} else if (rdev->mddev->pers) {
2461 		mdk_rdev_t *rdev2;
2462 		/* Activating a spare .. or possibly reactivating
2463 		 * if we ever get bitmaps working here.
2464 		 */
2465 
2466 		if (rdev->raid_disk != -1)
2467 			return -EBUSY;
2468 
2469 		if (rdev->mddev->pers->hot_add_disk == NULL)
2470 			return -EINVAL;
2471 
2472 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2473 			if (rdev2->raid_disk == slot)
2474 				return -EEXIST;
2475 
2476 		rdev->raid_disk = slot;
2477 		if (test_bit(In_sync, &rdev->flags))
2478 			rdev->saved_raid_disk = slot;
2479 		else
2480 			rdev->saved_raid_disk = -1;
2481 		err = rdev->mddev->pers->
2482 			hot_add_disk(rdev->mddev, rdev);
2483 		if (err) {
2484 			rdev->raid_disk = -1;
2485 			return err;
2486 		} else
2487 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2488 		sprintf(nm, "rd%d", rdev->raid_disk);
2489 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2490 			/* failure here is OK */;
2491 		/* don't wakeup anyone, leave that to userspace. */
2492 	} else {
2493 		if (slot >= rdev->mddev->raid_disks)
2494 			return -ENOSPC;
2495 		rdev->raid_disk = slot;
2496 		/* assume it is working */
2497 		clear_bit(Faulty, &rdev->flags);
2498 		clear_bit(WriteMostly, &rdev->flags);
2499 		set_bit(In_sync, &rdev->flags);
2500 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2501 	}
2502 	return len;
2503 }
2504 
2505 
2506 static struct rdev_sysfs_entry rdev_slot =
2507 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2508 
2509 static ssize_t
2510 offset_show(mdk_rdev_t *rdev, char *page)
2511 {
2512 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2513 }
2514 
2515 static ssize_t
2516 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2517 {
2518 	char *e;
2519 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2520 	if (e==buf || (*e && *e != '\n'))
2521 		return -EINVAL;
2522 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2523 		return -EBUSY;
2524 	if (rdev->sectors && rdev->mddev->external)
2525 		/* Must set offset before size, so overlap checks
2526 		 * can be sane */
2527 		return -EBUSY;
2528 	rdev->data_offset = offset;
2529 	return len;
2530 }
2531 
2532 static struct rdev_sysfs_entry rdev_offset =
2533 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2534 
2535 static ssize_t
2536 rdev_size_show(mdk_rdev_t *rdev, char *page)
2537 {
2538 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2539 }
2540 
2541 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2542 {
2543 	/* check if two start/length pairs overlap */
2544 	if (s1+l1 <= s2)
2545 		return 0;
2546 	if (s2+l2 <= s1)
2547 		return 0;
2548 	return 1;
2549 }
2550 
2551 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2552 {
2553 	unsigned long long blocks;
2554 	sector_t new;
2555 
2556 	if (strict_strtoull(buf, 10, &blocks) < 0)
2557 		return -EINVAL;
2558 
2559 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2560 		return -EINVAL; /* sector conversion overflow */
2561 
2562 	new = blocks * 2;
2563 	if (new != blocks * 2)
2564 		return -EINVAL; /* unsigned long long to sector_t overflow */
2565 
2566 	*sectors = new;
2567 	return 0;
2568 }
2569 
2570 static ssize_t
2571 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2572 {
2573 	mddev_t *my_mddev = rdev->mddev;
2574 	sector_t oldsectors = rdev->sectors;
2575 	sector_t sectors;
2576 
2577 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2578 		return -EINVAL;
2579 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2580 		if (my_mddev->persistent) {
2581 			sectors = super_types[my_mddev->major_version].
2582 				rdev_size_change(rdev, sectors);
2583 			if (!sectors)
2584 				return -EBUSY;
2585 		} else if (!sectors)
2586 			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2587 				rdev->data_offset;
2588 	}
2589 	if (sectors < my_mddev->dev_sectors)
2590 		return -EINVAL; /* component must fit device */
2591 
2592 	rdev->sectors = sectors;
2593 	if (sectors > oldsectors && my_mddev->external) {
2594 		/* need to check that all other rdevs with the same ->bdev
2595 		 * do not overlap.  We need to unlock the mddev to avoid
2596 		 * a deadlock.  We have already changed rdev->sectors, and if
2597 		 * we have to change it back, we will have the lock again.
2598 		 */
2599 		mddev_t *mddev;
2600 		int overlap = 0;
2601 		struct list_head *tmp;
2602 
2603 		mddev_unlock(my_mddev);
2604 		for_each_mddev(mddev, tmp) {
2605 			mdk_rdev_t *rdev2;
2606 
2607 			mddev_lock(mddev);
2608 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2609 				if (test_bit(AllReserved, &rdev2->flags) ||
2610 				    (rdev->bdev == rdev2->bdev &&
2611 				     rdev != rdev2 &&
2612 				     overlaps(rdev->data_offset, rdev->sectors,
2613 					      rdev2->data_offset,
2614 					      rdev2->sectors))) {
2615 					overlap = 1;
2616 					break;
2617 				}
2618 			mddev_unlock(mddev);
2619 			if (overlap) {
2620 				mddev_put(mddev);
2621 				break;
2622 			}
2623 		}
2624 		mddev_lock(my_mddev);
2625 		if (overlap) {
2626 			/* Someone else could have slipped in a size
2627 			 * change here, but doing so is just silly.
2628 			 * We put oldsectors back because we *know* it is
2629 			 * safe, and trust userspace not to race with
2630 			 * itself
2631 			 */
2632 			rdev->sectors = oldsectors;
2633 			return -EBUSY;
2634 		}
2635 	}
2636 	return len;
2637 }
2638 
2639 static struct rdev_sysfs_entry rdev_size =
2640 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2641 
2642 
2643 static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
2644 {
2645 	unsigned long long recovery_start = rdev->recovery_offset;
2646 
2647 	if (test_bit(In_sync, &rdev->flags) ||
2648 	    recovery_start == MaxSector)
2649 		return sprintf(page, "none\n");
2650 
2651 	return sprintf(page, "%llu\n", recovery_start);
2652 }
2653 
2654 static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2655 {
2656 	unsigned long long recovery_start;
2657 
2658 	if (cmd_match(buf, "none"))
2659 		recovery_start = MaxSector;
2660 	else if (strict_strtoull(buf, 10, &recovery_start))
2661 		return -EINVAL;
2662 
2663 	if (rdev->mddev->pers &&
2664 	    rdev->raid_disk >= 0)
2665 		return -EBUSY;
2666 
2667 	rdev->recovery_offset = recovery_start;
2668 	if (recovery_start == MaxSector)
2669 		set_bit(In_sync, &rdev->flags);
2670 	else
2671 		clear_bit(In_sync, &rdev->flags);
2672 	return len;
2673 }
2674 
2675 static struct rdev_sysfs_entry rdev_recovery_start =
2676 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
2677 
2678 static struct attribute *rdev_default_attrs[] = {
2679 	&rdev_state.attr,
2680 	&rdev_errors.attr,
2681 	&rdev_slot.attr,
2682 	&rdev_offset.attr,
2683 	&rdev_size.attr,
2684 	&rdev_recovery_start.attr,
2685 	NULL,
2686 };
2687 static ssize_t
2688 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2689 {
2690 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2691 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2692 	mddev_t *mddev = rdev->mddev;
2693 	ssize_t rv;
2694 
2695 	if (!entry->show)
2696 		return -EIO;
2697 
2698 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2699 	if (!rv) {
2700 		if (rdev->mddev == NULL)
2701 			rv = -EBUSY;
2702 		else
2703 			rv = entry->show(rdev, page);
2704 		mddev_unlock(mddev);
2705 	}
2706 	return rv;
2707 }
2708 
2709 static ssize_t
2710 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2711 	      const char *page, size_t length)
2712 {
2713 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2714 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2715 	ssize_t rv;
2716 	mddev_t *mddev = rdev->mddev;
2717 
2718 	if (!entry->store)
2719 		return -EIO;
2720 	if (!capable(CAP_SYS_ADMIN))
2721 		return -EACCES;
2722 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2723 	if (!rv) {
2724 		if (rdev->mddev == NULL)
2725 			rv = -EBUSY;
2726 		else
2727 			rv = entry->store(rdev, page, length);
2728 		mddev_unlock(mddev);
2729 	}
2730 	return rv;
2731 }
2732 
2733 static void rdev_free(struct kobject *ko)
2734 {
2735 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2736 	kfree(rdev);
2737 }
2738 static const struct sysfs_ops rdev_sysfs_ops = {
2739 	.show		= rdev_attr_show,
2740 	.store		= rdev_attr_store,
2741 };
2742 static struct kobj_type rdev_ktype = {
2743 	.release	= rdev_free,
2744 	.sysfs_ops	= &rdev_sysfs_ops,
2745 	.default_attrs	= rdev_default_attrs,
2746 };
2747 
2748 void md_rdev_init(mdk_rdev_t *rdev)
2749 {
2750 	rdev->desc_nr = -1;
2751 	rdev->saved_raid_disk = -1;
2752 	rdev->raid_disk = -1;
2753 	rdev->flags = 0;
2754 	rdev->data_offset = 0;
2755 	rdev->sb_events = 0;
2756 	rdev->last_read_error.tv_sec  = 0;
2757 	rdev->last_read_error.tv_nsec = 0;
2758 	atomic_set(&rdev->nr_pending, 0);
2759 	atomic_set(&rdev->read_errors, 0);
2760 	atomic_set(&rdev->corrected_errors, 0);
2761 
2762 	INIT_LIST_HEAD(&rdev->same_set);
2763 	init_waitqueue_head(&rdev->blocked_wait);
2764 }
2765 EXPORT_SYMBOL_GPL(md_rdev_init);
2766 /*
2767  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2768  *
2769  * mark the device faulty if:
2770  *
2771  *   - the device is nonexistent (zero size)
2772  *   - the device has no valid superblock
2773  *
2774  * a faulty rdev _never_ has rdev->sb set.
2775  */
2776 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2777 {
2778 	char b[BDEVNAME_SIZE];
2779 	int err;
2780 	mdk_rdev_t *rdev;
2781 	sector_t size;
2782 
2783 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2784 	if (!rdev) {
2785 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2786 		return ERR_PTR(-ENOMEM);
2787 	}
2788 
2789 	md_rdev_init(rdev);
2790 	if ((err = alloc_disk_sb(rdev)))
2791 		goto abort_free;
2792 
2793 	err = lock_rdev(rdev, newdev, super_format == -2);
2794 	if (err)
2795 		goto abort_free;
2796 
2797 	kobject_init(&rdev->kobj, &rdev_ktype);
2798 
2799 	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
2800 	if (!size) {
2801 		printk(KERN_WARNING
2802 			"md: %s has zero or unknown size, marking faulty!\n",
2803 			bdevname(rdev->bdev,b));
2804 		err = -EINVAL;
2805 		goto abort_free;
2806 	}
2807 
2808 	if (super_format >= 0) {
2809 		err = super_types[super_format].
2810 			load_super(rdev, NULL, super_minor);
2811 		if (err == -EINVAL) {
2812 			printk(KERN_WARNING
2813 				"md: %s does not have a valid v%d.%d "
2814 			       "superblock, not importing!\n",
2815 				bdevname(rdev->bdev,b),
2816 			       super_format, super_minor);
2817 			goto abort_free;
2818 		}
2819 		if (err < 0) {
2820 			printk(KERN_WARNING
2821 				"md: could not read %s's sb, not importing!\n",
2822 				bdevname(rdev->bdev,b));
2823 			goto abort_free;
2824 		}
2825 	}
2826 
2827 	return rdev;
2828 
2829 abort_free:
2830 	if (rdev->sb_page) {
2831 		if (rdev->bdev)
2832 			unlock_rdev(rdev);
2833 		free_disk_sb(rdev);
2834 	}
2835 	kfree(rdev);
2836 	return ERR_PTR(err);
2837 }
2838 
2839 /*
2840  * Check a full RAID array for plausibility
2841  */
2842 
2843 
2844 static void analyze_sbs(mddev_t * mddev)
2845 {
2846 	int i;
2847 	mdk_rdev_t *rdev, *freshest, *tmp;
2848 	char b[BDEVNAME_SIZE];
2849 
2850 	freshest = NULL;
2851 	rdev_for_each(rdev, tmp, mddev)
2852 		switch (super_types[mddev->major_version].
2853 			load_super(rdev, freshest, mddev->minor_version)) {
2854 		case 1:
2855 			freshest = rdev;
2856 			break;
2857 		case 0:
2858 			break;
2859 		default:
2860 			printk( KERN_ERR \
2861 				"md: fatal superblock inconsistency in %s"
2862 				" -- removing from array\n",
2863 				bdevname(rdev->bdev,b));
2864 			kick_rdev_from_array(rdev);
2865 		}
2866 
2867 
2868 	super_types[mddev->major_version].
2869 		validate_super(mddev, freshest);
2870 
2871 	i = 0;
2872 	rdev_for_each(rdev, tmp, mddev) {
2873 		if (mddev->max_disks &&
2874 		    (rdev->desc_nr >= mddev->max_disks ||
2875 		     i > mddev->max_disks)) {
2876 			printk(KERN_WARNING
2877 			       "md: %s: %s: only %d devices permitted\n",
2878 			       mdname(mddev), bdevname(rdev->bdev, b),
2879 			       mddev->max_disks);
2880 			kick_rdev_from_array(rdev);
2881 			continue;
2882 		}
2883 		if (rdev != freshest)
2884 			if (super_types[mddev->major_version].
2885 			    validate_super(mddev, rdev)) {
2886 				printk(KERN_WARNING "md: kicking non-fresh %s"
2887 					" from array!\n",
2888 					bdevname(rdev->bdev,b));
2889 				kick_rdev_from_array(rdev);
2890 				continue;
2891 			}
2892 		if (mddev->level == LEVEL_MULTIPATH) {
2893 			rdev->desc_nr = i++;
2894 			rdev->raid_disk = rdev->desc_nr;
2895 			set_bit(In_sync, &rdev->flags);
2896 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
2897 			rdev->raid_disk = -1;
2898 			clear_bit(In_sync, &rdev->flags);
2899 		}
2900 	}
2901 }
2902 
2903 /* Read a fixed-point number.
2904  * Numbers in sysfs attributes should be in "standard" units where
2905  * possible, so time should be in seconds.
2906  * However we internally use a a much smaller unit such as
2907  * milliseconds or jiffies.
2908  * This function takes a decimal number with a possible fractional
2909  * component, and produces an integer which is the result of
2910  * multiplying that number by 10^'scale'.
2911  * all without any floating-point arithmetic.
2912  */
2913 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
2914 {
2915 	unsigned long result = 0;
2916 	long decimals = -1;
2917 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
2918 		if (*cp == '.')
2919 			decimals = 0;
2920 		else if (decimals < scale) {
2921 			unsigned int value;
2922 			value = *cp - '0';
2923 			result = result * 10 + value;
2924 			if (decimals >= 0)
2925 				decimals++;
2926 		}
2927 		cp++;
2928 	}
2929 	if (*cp == '\n')
2930 		cp++;
2931 	if (*cp)
2932 		return -EINVAL;
2933 	if (decimals < 0)
2934 		decimals = 0;
2935 	while (decimals < scale) {
2936 		result *= 10;
2937 		decimals ++;
2938 	}
2939 	*res = result;
2940 	return 0;
2941 }
2942 
2943 
2944 static void md_safemode_timeout(unsigned long data);
2945 
2946 static ssize_t
2947 safe_delay_show(mddev_t *mddev, char *page)
2948 {
2949 	int msec = (mddev->safemode_delay*1000)/HZ;
2950 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2951 }
2952 static ssize_t
2953 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2954 {
2955 	unsigned long msec;
2956 
2957 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
2958 		return -EINVAL;
2959 	if (msec == 0)
2960 		mddev->safemode_delay = 0;
2961 	else {
2962 		unsigned long old_delay = mddev->safemode_delay;
2963 		mddev->safemode_delay = (msec*HZ)/1000;
2964 		if (mddev->safemode_delay == 0)
2965 			mddev->safemode_delay = 1;
2966 		if (mddev->safemode_delay < old_delay)
2967 			md_safemode_timeout((unsigned long)mddev);
2968 	}
2969 	return len;
2970 }
2971 static struct md_sysfs_entry md_safe_delay =
2972 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2973 
2974 static ssize_t
2975 level_show(mddev_t *mddev, char *page)
2976 {
2977 	struct mdk_personality *p = mddev->pers;
2978 	if (p)
2979 		return sprintf(page, "%s\n", p->name);
2980 	else if (mddev->clevel[0])
2981 		return sprintf(page, "%s\n", mddev->clevel);
2982 	else if (mddev->level != LEVEL_NONE)
2983 		return sprintf(page, "%d\n", mddev->level);
2984 	else
2985 		return 0;
2986 }
2987 
2988 static ssize_t
2989 level_store(mddev_t *mddev, const char *buf, size_t len)
2990 {
2991 	char clevel[16];
2992 	ssize_t rv = len;
2993 	struct mdk_personality *pers;
2994 	long level;
2995 	void *priv;
2996 	mdk_rdev_t *rdev;
2997 
2998 	if (mddev->pers == NULL) {
2999 		if (len == 0)
3000 			return 0;
3001 		if (len >= sizeof(mddev->clevel))
3002 			return -ENOSPC;
3003 		strncpy(mddev->clevel, buf, len);
3004 		if (mddev->clevel[len-1] == '\n')
3005 			len--;
3006 		mddev->clevel[len] = 0;
3007 		mddev->level = LEVEL_NONE;
3008 		return rv;
3009 	}
3010 
3011 	/* request to change the personality.  Need to ensure:
3012 	 *  - array is not engaged in resync/recovery/reshape
3013 	 *  - old personality can be suspended
3014 	 *  - new personality will access other array.
3015 	 */
3016 
3017 	if (mddev->sync_thread ||
3018 	    mddev->reshape_position != MaxSector ||
3019 	    mddev->sysfs_active)
3020 		return -EBUSY;
3021 
3022 	if (!mddev->pers->quiesce) {
3023 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3024 		       mdname(mddev), mddev->pers->name);
3025 		return -EINVAL;
3026 	}
3027 
3028 	/* Now find the new personality */
3029 	if (len == 0 || len >= sizeof(clevel))
3030 		return -EINVAL;
3031 	strncpy(clevel, buf, len);
3032 	if (clevel[len-1] == '\n')
3033 		len--;
3034 	clevel[len] = 0;
3035 	if (strict_strtol(clevel, 10, &level))
3036 		level = LEVEL_NONE;
3037 
3038 	if (request_module("md-%s", clevel) != 0)
3039 		request_module("md-level-%s", clevel);
3040 	spin_lock(&pers_lock);
3041 	pers = find_pers(level, clevel);
3042 	if (!pers || !try_module_get(pers->owner)) {
3043 		spin_unlock(&pers_lock);
3044 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3045 		return -EINVAL;
3046 	}
3047 	spin_unlock(&pers_lock);
3048 
3049 	if (pers == mddev->pers) {
3050 		/* Nothing to do! */
3051 		module_put(pers->owner);
3052 		return rv;
3053 	}
3054 	if (!pers->takeover) {
3055 		module_put(pers->owner);
3056 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3057 		       mdname(mddev), clevel);
3058 		return -EINVAL;
3059 	}
3060 
3061 	list_for_each_entry(rdev, &mddev->disks, same_set)
3062 		rdev->new_raid_disk = rdev->raid_disk;
3063 
3064 	/* ->takeover must set new_* and/or delta_disks
3065 	 * if it succeeds, and may set them when it fails.
3066 	 */
3067 	priv = pers->takeover(mddev);
3068 	if (IS_ERR(priv)) {
3069 		mddev->new_level = mddev->level;
3070 		mddev->new_layout = mddev->layout;
3071 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3072 		mddev->raid_disks -= mddev->delta_disks;
3073 		mddev->delta_disks = 0;
3074 		module_put(pers->owner);
3075 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3076 		       mdname(mddev), clevel);
3077 		return PTR_ERR(priv);
3078 	}
3079 
3080 	/* Looks like we have a winner */
3081 	mddev_suspend(mddev);
3082 	mddev->pers->stop(mddev);
3083 
3084 	if (mddev->pers->sync_request == NULL &&
3085 	    pers->sync_request != NULL) {
3086 		/* need to add the md_redundancy_group */
3087 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3088 			printk(KERN_WARNING
3089 			       "md: cannot register extra attributes for %s\n",
3090 			       mdname(mddev));
3091 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3092 	}
3093 	if (mddev->pers->sync_request != NULL &&
3094 	    pers->sync_request == NULL) {
3095 		/* need to remove the md_redundancy_group */
3096 		if (mddev->to_remove == NULL)
3097 			mddev->to_remove = &md_redundancy_group;
3098 	}
3099 
3100 	if (mddev->pers->sync_request == NULL &&
3101 	    mddev->external) {
3102 		/* We are converting from a no-redundancy array
3103 		 * to a redundancy array and metadata is managed
3104 		 * externally so we need to be sure that writes
3105 		 * won't block due to a need to transition
3106 		 *      clean->dirty
3107 		 * until external management is started.
3108 		 */
3109 		mddev->in_sync = 0;
3110 		mddev->safemode_delay = 0;
3111 		mddev->safemode = 0;
3112 	}
3113 
3114 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3115 		char nm[20];
3116 		if (rdev->raid_disk < 0)
3117 			continue;
3118 		if (rdev->new_raid_disk > mddev->raid_disks)
3119 			rdev->new_raid_disk = -1;
3120 		if (rdev->new_raid_disk == rdev->raid_disk)
3121 			continue;
3122 		sprintf(nm, "rd%d", rdev->raid_disk);
3123 		sysfs_remove_link(&mddev->kobj, nm);
3124 	}
3125 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3126 		if (rdev->raid_disk < 0)
3127 			continue;
3128 		if (rdev->new_raid_disk == rdev->raid_disk)
3129 			continue;
3130 		rdev->raid_disk = rdev->new_raid_disk;
3131 		if (rdev->raid_disk < 0)
3132 			clear_bit(In_sync, &rdev->flags);
3133 		else {
3134 			char nm[20];
3135 			sprintf(nm, "rd%d", rdev->raid_disk);
3136 			if(sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
3137 				printk("md: cannot register %s for %s after level change\n",
3138 				       nm, mdname(mddev));
3139 		}
3140 	}
3141 
3142 	module_put(mddev->pers->owner);
3143 	mddev->pers = pers;
3144 	mddev->private = priv;
3145 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3146 	mddev->level = mddev->new_level;
3147 	mddev->layout = mddev->new_layout;
3148 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3149 	mddev->delta_disks = 0;
3150 	if (mddev->pers->sync_request == NULL) {
3151 		/* this is now an array without redundancy, so
3152 		 * it must always be in_sync
3153 		 */
3154 		mddev->in_sync = 1;
3155 		del_timer_sync(&mddev->safemode_timer);
3156 	}
3157 	pers->run(mddev);
3158 	mddev_resume(mddev);
3159 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3160 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3161 	md_wakeup_thread(mddev->thread);
3162 	sysfs_notify(&mddev->kobj, NULL, "level");
3163 	md_new_event(mddev);
3164 	return rv;
3165 }
3166 
3167 static struct md_sysfs_entry md_level =
3168 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3169 
3170 
3171 static ssize_t
3172 layout_show(mddev_t *mddev, char *page)
3173 {
3174 	/* just a number, not meaningful for all levels */
3175 	if (mddev->reshape_position != MaxSector &&
3176 	    mddev->layout != mddev->new_layout)
3177 		return sprintf(page, "%d (%d)\n",
3178 			       mddev->new_layout, mddev->layout);
3179 	return sprintf(page, "%d\n", mddev->layout);
3180 }
3181 
3182 static ssize_t
3183 layout_store(mddev_t *mddev, const char *buf, size_t len)
3184 {
3185 	char *e;
3186 	unsigned long n = simple_strtoul(buf, &e, 10);
3187 
3188 	if (!*buf || (*e && *e != '\n'))
3189 		return -EINVAL;
3190 
3191 	if (mddev->pers) {
3192 		int err;
3193 		if (mddev->pers->check_reshape == NULL)
3194 			return -EBUSY;
3195 		mddev->new_layout = n;
3196 		err = mddev->pers->check_reshape(mddev);
3197 		if (err) {
3198 			mddev->new_layout = mddev->layout;
3199 			return err;
3200 		}
3201 	} else {
3202 		mddev->new_layout = n;
3203 		if (mddev->reshape_position == MaxSector)
3204 			mddev->layout = n;
3205 	}
3206 	return len;
3207 }
3208 static struct md_sysfs_entry md_layout =
3209 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3210 
3211 
3212 static ssize_t
3213 raid_disks_show(mddev_t *mddev, char *page)
3214 {
3215 	if (mddev->raid_disks == 0)
3216 		return 0;
3217 	if (mddev->reshape_position != MaxSector &&
3218 	    mddev->delta_disks != 0)
3219 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3220 			       mddev->raid_disks - mddev->delta_disks);
3221 	return sprintf(page, "%d\n", mddev->raid_disks);
3222 }
3223 
3224 static int update_raid_disks(mddev_t *mddev, int raid_disks);
3225 
3226 static ssize_t
3227 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
3228 {
3229 	char *e;
3230 	int rv = 0;
3231 	unsigned long n = simple_strtoul(buf, &e, 10);
3232 
3233 	if (!*buf || (*e && *e != '\n'))
3234 		return -EINVAL;
3235 
3236 	if (mddev->pers)
3237 		rv = update_raid_disks(mddev, n);
3238 	else if (mddev->reshape_position != MaxSector) {
3239 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3240 		mddev->delta_disks = n - olddisks;
3241 		mddev->raid_disks = n;
3242 	} else
3243 		mddev->raid_disks = n;
3244 	return rv ? rv : len;
3245 }
3246 static struct md_sysfs_entry md_raid_disks =
3247 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3248 
3249 static ssize_t
3250 chunk_size_show(mddev_t *mddev, char *page)
3251 {
3252 	if (mddev->reshape_position != MaxSector &&
3253 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3254 		return sprintf(page, "%d (%d)\n",
3255 			       mddev->new_chunk_sectors << 9,
3256 			       mddev->chunk_sectors << 9);
3257 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3258 }
3259 
3260 static ssize_t
3261 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
3262 {
3263 	char *e;
3264 	unsigned long n = simple_strtoul(buf, &e, 10);
3265 
3266 	if (!*buf || (*e && *e != '\n'))
3267 		return -EINVAL;
3268 
3269 	if (mddev->pers) {
3270 		int err;
3271 		if (mddev->pers->check_reshape == NULL)
3272 			return -EBUSY;
3273 		mddev->new_chunk_sectors = n >> 9;
3274 		err = mddev->pers->check_reshape(mddev);
3275 		if (err) {
3276 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3277 			return err;
3278 		}
3279 	} else {
3280 		mddev->new_chunk_sectors = n >> 9;
3281 		if (mddev->reshape_position == MaxSector)
3282 			mddev->chunk_sectors = n >> 9;
3283 	}
3284 	return len;
3285 }
3286 static struct md_sysfs_entry md_chunk_size =
3287 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3288 
3289 static ssize_t
3290 resync_start_show(mddev_t *mddev, char *page)
3291 {
3292 	if (mddev->recovery_cp == MaxSector)
3293 		return sprintf(page, "none\n");
3294 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3295 }
3296 
3297 static ssize_t
3298 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
3299 {
3300 	char *e;
3301 	unsigned long long n = simple_strtoull(buf, &e, 10);
3302 
3303 	if (mddev->pers)
3304 		return -EBUSY;
3305 	if (cmd_match(buf, "none"))
3306 		n = MaxSector;
3307 	else if (!*buf || (*e && *e != '\n'))
3308 		return -EINVAL;
3309 
3310 	mddev->recovery_cp = n;
3311 	return len;
3312 }
3313 static struct md_sysfs_entry md_resync_start =
3314 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3315 
3316 /*
3317  * The array state can be:
3318  *
3319  * clear
3320  *     No devices, no size, no level
3321  *     Equivalent to STOP_ARRAY ioctl
3322  * inactive
3323  *     May have some settings, but array is not active
3324  *        all IO results in error
3325  *     When written, doesn't tear down array, but just stops it
3326  * suspended (not supported yet)
3327  *     All IO requests will block. The array can be reconfigured.
3328  *     Writing this, if accepted, will block until array is quiescent
3329  * readonly
3330  *     no resync can happen.  no superblocks get written.
3331  *     write requests fail
3332  * read-auto
3333  *     like readonly, but behaves like 'clean' on a write request.
3334  *
3335  * clean - no pending writes, but otherwise active.
3336  *     When written to inactive array, starts without resync
3337  *     If a write request arrives then
3338  *       if metadata is known, mark 'dirty' and switch to 'active'.
3339  *       if not known, block and switch to write-pending
3340  *     If written to an active array that has pending writes, then fails.
3341  * active
3342  *     fully active: IO and resync can be happening.
3343  *     When written to inactive array, starts with resync
3344  *
3345  * write-pending
3346  *     clean, but writes are blocked waiting for 'active' to be written.
3347  *
3348  * active-idle
3349  *     like active, but no writes have been seen for a while (100msec).
3350  *
3351  */
3352 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3353 		   write_pending, active_idle, bad_word};
3354 static char *array_states[] = {
3355 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3356 	"write-pending", "active-idle", NULL };
3357 
3358 static int match_word(const char *word, char **list)
3359 {
3360 	int n;
3361 	for (n=0; list[n]; n++)
3362 		if (cmd_match(word, list[n]))
3363 			break;
3364 	return n;
3365 }
3366 
3367 static ssize_t
3368 array_state_show(mddev_t *mddev, char *page)
3369 {
3370 	enum array_state st = inactive;
3371 
3372 	if (mddev->pers)
3373 		switch(mddev->ro) {
3374 		case 1:
3375 			st = readonly;
3376 			break;
3377 		case 2:
3378 			st = read_auto;
3379 			break;
3380 		case 0:
3381 			if (mddev->in_sync)
3382 				st = clean;
3383 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3384 				st = write_pending;
3385 			else if (mddev->safemode)
3386 				st = active_idle;
3387 			else
3388 				st = active;
3389 		}
3390 	else {
3391 		if (list_empty(&mddev->disks) &&
3392 		    mddev->raid_disks == 0 &&
3393 		    mddev->dev_sectors == 0)
3394 			st = clear;
3395 		else
3396 			st = inactive;
3397 	}
3398 	return sprintf(page, "%s\n", array_states[st]);
3399 }
3400 
3401 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3402 static int md_set_readonly(mddev_t * mddev, int is_open);
3403 static int do_md_run(mddev_t * mddev);
3404 static int restart_array(mddev_t *mddev);
3405 
3406 static ssize_t
3407 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3408 {
3409 	int err = -EINVAL;
3410 	enum array_state st = match_word(buf, array_states);
3411 	switch(st) {
3412 	case bad_word:
3413 		break;
3414 	case clear:
3415 		/* stopping an active array */
3416 		if (atomic_read(&mddev->openers) > 0)
3417 			return -EBUSY;
3418 		err = do_md_stop(mddev, 0, 0);
3419 		break;
3420 	case inactive:
3421 		/* stopping an active array */
3422 		if (mddev->pers) {
3423 			if (atomic_read(&mddev->openers) > 0)
3424 				return -EBUSY;
3425 			err = do_md_stop(mddev, 2, 0);
3426 		} else
3427 			err = 0; /* already inactive */
3428 		break;
3429 	case suspended:
3430 		break; /* not supported yet */
3431 	case readonly:
3432 		if (mddev->pers)
3433 			err = md_set_readonly(mddev, 0);
3434 		else {
3435 			mddev->ro = 1;
3436 			set_disk_ro(mddev->gendisk, 1);
3437 			err = do_md_run(mddev);
3438 		}
3439 		break;
3440 	case read_auto:
3441 		if (mddev->pers) {
3442 			if (mddev->ro == 0)
3443 				err = md_set_readonly(mddev, 0);
3444 			else if (mddev->ro == 1)
3445 				err = restart_array(mddev);
3446 			if (err == 0) {
3447 				mddev->ro = 2;
3448 				set_disk_ro(mddev->gendisk, 0);
3449 			}
3450 		} else {
3451 			mddev->ro = 2;
3452 			err = do_md_run(mddev);
3453 		}
3454 		break;
3455 	case clean:
3456 		if (mddev->pers) {
3457 			restart_array(mddev);
3458 			spin_lock_irq(&mddev->write_lock);
3459 			if (atomic_read(&mddev->writes_pending) == 0) {
3460 				if (mddev->in_sync == 0) {
3461 					mddev->in_sync = 1;
3462 					if (mddev->safemode == 1)
3463 						mddev->safemode = 0;
3464 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3465 				}
3466 				err = 0;
3467 			} else
3468 				err = -EBUSY;
3469 			spin_unlock_irq(&mddev->write_lock);
3470 		} else
3471 			err = -EINVAL;
3472 		break;
3473 	case active:
3474 		if (mddev->pers) {
3475 			restart_array(mddev);
3476 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3477 			wake_up(&mddev->sb_wait);
3478 			err = 0;
3479 		} else {
3480 			mddev->ro = 0;
3481 			set_disk_ro(mddev->gendisk, 0);
3482 			err = do_md_run(mddev);
3483 		}
3484 		break;
3485 	case write_pending:
3486 	case active_idle:
3487 		/* these cannot be set */
3488 		break;
3489 	}
3490 	if (err)
3491 		return err;
3492 	else {
3493 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3494 		return len;
3495 	}
3496 }
3497 static struct md_sysfs_entry md_array_state =
3498 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3499 
3500 static ssize_t
3501 max_corrected_read_errors_show(mddev_t *mddev, char *page) {
3502 	return sprintf(page, "%d\n",
3503 		       atomic_read(&mddev->max_corr_read_errors));
3504 }
3505 
3506 static ssize_t
3507 max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
3508 {
3509 	char *e;
3510 	unsigned long n = simple_strtoul(buf, &e, 10);
3511 
3512 	if (*buf && (*e == 0 || *e == '\n')) {
3513 		atomic_set(&mddev->max_corr_read_errors, n);
3514 		return len;
3515 	}
3516 	return -EINVAL;
3517 }
3518 
3519 static struct md_sysfs_entry max_corr_read_errors =
3520 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3521 	max_corrected_read_errors_store);
3522 
3523 static ssize_t
3524 null_show(mddev_t *mddev, char *page)
3525 {
3526 	return -EINVAL;
3527 }
3528 
3529 static ssize_t
3530 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3531 {
3532 	/* buf must be %d:%d\n? giving major and minor numbers */
3533 	/* The new device is added to the array.
3534 	 * If the array has a persistent superblock, we read the
3535 	 * superblock to initialise info and check validity.
3536 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3537 	 * which mainly checks size.
3538 	 */
3539 	char *e;
3540 	int major = simple_strtoul(buf, &e, 10);
3541 	int minor;
3542 	dev_t dev;
3543 	mdk_rdev_t *rdev;
3544 	int err;
3545 
3546 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3547 		return -EINVAL;
3548 	minor = simple_strtoul(e+1, &e, 10);
3549 	if (*e && *e != '\n')
3550 		return -EINVAL;
3551 	dev = MKDEV(major, minor);
3552 	if (major != MAJOR(dev) ||
3553 	    minor != MINOR(dev))
3554 		return -EOVERFLOW;
3555 
3556 
3557 	if (mddev->persistent) {
3558 		rdev = md_import_device(dev, mddev->major_version,
3559 					mddev->minor_version);
3560 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3561 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3562 						       mdk_rdev_t, same_set);
3563 			err = super_types[mddev->major_version]
3564 				.load_super(rdev, rdev0, mddev->minor_version);
3565 			if (err < 0)
3566 				goto out;
3567 		}
3568 	} else if (mddev->external)
3569 		rdev = md_import_device(dev, -2, -1);
3570 	else
3571 		rdev = md_import_device(dev, -1, -1);
3572 
3573 	if (IS_ERR(rdev))
3574 		return PTR_ERR(rdev);
3575 	err = bind_rdev_to_array(rdev, mddev);
3576  out:
3577 	if (err)
3578 		export_rdev(rdev);
3579 	return err ? err : len;
3580 }
3581 
3582 static struct md_sysfs_entry md_new_device =
3583 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3584 
3585 static ssize_t
3586 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3587 {
3588 	char *end;
3589 	unsigned long chunk, end_chunk;
3590 
3591 	if (!mddev->bitmap)
3592 		goto out;
3593 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3594 	while (*buf) {
3595 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3596 		if (buf == end) break;
3597 		if (*end == '-') { /* range */
3598 			buf = end + 1;
3599 			end_chunk = simple_strtoul(buf, &end, 0);
3600 			if (buf == end) break;
3601 		}
3602 		if (*end && !isspace(*end)) break;
3603 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3604 		buf = skip_spaces(end);
3605 	}
3606 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3607 out:
3608 	return len;
3609 }
3610 
3611 static struct md_sysfs_entry md_bitmap =
3612 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3613 
3614 static ssize_t
3615 size_show(mddev_t *mddev, char *page)
3616 {
3617 	return sprintf(page, "%llu\n",
3618 		(unsigned long long)mddev->dev_sectors / 2);
3619 }
3620 
3621 static int update_size(mddev_t *mddev, sector_t num_sectors);
3622 
3623 static ssize_t
3624 size_store(mddev_t *mddev, const char *buf, size_t len)
3625 {
3626 	/* If array is inactive, we can reduce the component size, but
3627 	 * not increase it (except from 0).
3628 	 * If array is active, we can try an on-line resize
3629 	 */
3630 	sector_t sectors;
3631 	int err = strict_blocks_to_sectors(buf, &sectors);
3632 
3633 	if (err < 0)
3634 		return err;
3635 	if (mddev->pers) {
3636 		err = update_size(mddev, sectors);
3637 		md_update_sb(mddev, 1);
3638 	} else {
3639 		if (mddev->dev_sectors == 0 ||
3640 		    mddev->dev_sectors > sectors)
3641 			mddev->dev_sectors = sectors;
3642 		else
3643 			err = -ENOSPC;
3644 	}
3645 	return err ? err : len;
3646 }
3647 
3648 static struct md_sysfs_entry md_size =
3649 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3650 
3651 
3652 /* Metdata version.
3653  * This is one of
3654  *   'none' for arrays with no metadata (good luck...)
3655  *   'external' for arrays with externally managed metadata,
3656  * or N.M for internally known formats
3657  */
3658 static ssize_t
3659 metadata_show(mddev_t *mddev, char *page)
3660 {
3661 	if (mddev->persistent)
3662 		return sprintf(page, "%d.%d\n",
3663 			       mddev->major_version, mddev->minor_version);
3664 	else if (mddev->external)
3665 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3666 	else
3667 		return sprintf(page, "none\n");
3668 }
3669 
3670 static ssize_t
3671 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3672 {
3673 	int major, minor;
3674 	char *e;
3675 	/* Changing the details of 'external' metadata is
3676 	 * always permitted.  Otherwise there must be
3677 	 * no devices attached to the array.
3678 	 */
3679 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3680 		;
3681 	else if (!list_empty(&mddev->disks))
3682 		return -EBUSY;
3683 
3684 	if (cmd_match(buf, "none")) {
3685 		mddev->persistent = 0;
3686 		mddev->external = 0;
3687 		mddev->major_version = 0;
3688 		mddev->minor_version = 90;
3689 		return len;
3690 	}
3691 	if (strncmp(buf, "external:", 9) == 0) {
3692 		size_t namelen = len-9;
3693 		if (namelen >= sizeof(mddev->metadata_type))
3694 			namelen = sizeof(mddev->metadata_type)-1;
3695 		strncpy(mddev->metadata_type, buf+9, namelen);
3696 		mddev->metadata_type[namelen] = 0;
3697 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3698 			mddev->metadata_type[--namelen] = 0;
3699 		mddev->persistent = 0;
3700 		mddev->external = 1;
3701 		mddev->major_version = 0;
3702 		mddev->minor_version = 90;
3703 		return len;
3704 	}
3705 	major = simple_strtoul(buf, &e, 10);
3706 	if (e==buf || *e != '.')
3707 		return -EINVAL;
3708 	buf = e+1;
3709 	minor = simple_strtoul(buf, &e, 10);
3710 	if (e==buf || (*e && *e != '\n') )
3711 		return -EINVAL;
3712 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3713 		return -ENOENT;
3714 	mddev->major_version = major;
3715 	mddev->minor_version = minor;
3716 	mddev->persistent = 1;
3717 	mddev->external = 0;
3718 	return len;
3719 }
3720 
3721 static struct md_sysfs_entry md_metadata =
3722 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3723 
3724 static ssize_t
3725 action_show(mddev_t *mddev, char *page)
3726 {
3727 	char *type = "idle";
3728 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3729 		type = "frozen";
3730 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3731 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3732 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3733 			type = "reshape";
3734 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3735 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3736 				type = "resync";
3737 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3738 				type = "check";
3739 			else
3740 				type = "repair";
3741 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3742 			type = "recover";
3743 	}
3744 	return sprintf(page, "%s\n", type);
3745 }
3746 
3747 static ssize_t
3748 action_store(mddev_t *mddev, const char *page, size_t len)
3749 {
3750 	if (!mddev->pers || !mddev->pers->sync_request)
3751 		return -EINVAL;
3752 
3753 	if (cmd_match(page, "frozen"))
3754 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3755 	else
3756 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3757 
3758 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
3759 		if (mddev->sync_thread) {
3760 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3761 			md_unregister_thread(mddev->sync_thread);
3762 			mddev->sync_thread = NULL;
3763 			mddev->recovery = 0;
3764 		}
3765 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3766 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3767 		return -EBUSY;
3768 	else if (cmd_match(page, "resync"))
3769 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3770 	else if (cmd_match(page, "recover")) {
3771 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3772 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3773 	} else if (cmd_match(page, "reshape")) {
3774 		int err;
3775 		if (mddev->pers->start_reshape == NULL)
3776 			return -EINVAL;
3777 		err = mddev->pers->start_reshape(mddev);
3778 		if (err)
3779 			return err;
3780 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3781 	} else {
3782 		if (cmd_match(page, "check"))
3783 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3784 		else if (!cmd_match(page, "repair"))
3785 			return -EINVAL;
3786 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3787 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3788 	}
3789 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3790 	md_wakeup_thread(mddev->thread);
3791 	sysfs_notify_dirent_safe(mddev->sysfs_action);
3792 	return len;
3793 }
3794 
3795 static ssize_t
3796 mismatch_cnt_show(mddev_t *mddev, char *page)
3797 {
3798 	return sprintf(page, "%llu\n",
3799 		       (unsigned long long) mddev->resync_mismatches);
3800 }
3801 
3802 static struct md_sysfs_entry md_scan_mode =
3803 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3804 
3805 
3806 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3807 
3808 static ssize_t
3809 sync_min_show(mddev_t *mddev, char *page)
3810 {
3811 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3812 		       mddev->sync_speed_min ? "local": "system");
3813 }
3814 
3815 static ssize_t
3816 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3817 {
3818 	int min;
3819 	char *e;
3820 	if (strncmp(buf, "system", 6)==0) {
3821 		mddev->sync_speed_min = 0;
3822 		return len;
3823 	}
3824 	min = simple_strtoul(buf, &e, 10);
3825 	if (buf == e || (*e && *e != '\n') || min <= 0)
3826 		return -EINVAL;
3827 	mddev->sync_speed_min = min;
3828 	return len;
3829 }
3830 
3831 static struct md_sysfs_entry md_sync_min =
3832 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3833 
3834 static ssize_t
3835 sync_max_show(mddev_t *mddev, char *page)
3836 {
3837 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3838 		       mddev->sync_speed_max ? "local": "system");
3839 }
3840 
3841 static ssize_t
3842 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3843 {
3844 	int max;
3845 	char *e;
3846 	if (strncmp(buf, "system", 6)==0) {
3847 		mddev->sync_speed_max = 0;
3848 		return len;
3849 	}
3850 	max = simple_strtoul(buf, &e, 10);
3851 	if (buf == e || (*e && *e != '\n') || max <= 0)
3852 		return -EINVAL;
3853 	mddev->sync_speed_max = max;
3854 	return len;
3855 }
3856 
3857 static struct md_sysfs_entry md_sync_max =
3858 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3859 
3860 static ssize_t
3861 degraded_show(mddev_t *mddev, char *page)
3862 {
3863 	return sprintf(page, "%d\n", mddev->degraded);
3864 }
3865 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3866 
3867 static ssize_t
3868 sync_force_parallel_show(mddev_t *mddev, char *page)
3869 {
3870 	return sprintf(page, "%d\n", mddev->parallel_resync);
3871 }
3872 
3873 static ssize_t
3874 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3875 {
3876 	long n;
3877 
3878 	if (strict_strtol(buf, 10, &n))
3879 		return -EINVAL;
3880 
3881 	if (n != 0 && n != 1)
3882 		return -EINVAL;
3883 
3884 	mddev->parallel_resync = n;
3885 
3886 	if (mddev->sync_thread)
3887 		wake_up(&resync_wait);
3888 
3889 	return len;
3890 }
3891 
3892 /* force parallel resync, even with shared block devices */
3893 static struct md_sysfs_entry md_sync_force_parallel =
3894 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3895        sync_force_parallel_show, sync_force_parallel_store);
3896 
3897 static ssize_t
3898 sync_speed_show(mddev_t *mddev, char *page)
3899 {
3900 	unsigned long resync, dt, db;
3901 	if (mddev->curr_resync == 0)
3902 		return sprintf(page, "none\n");
3903 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3904 	dt = (jiffies - mddev->resync_mark) / HZ;
3905 	if (!dt) dt++;
3906 	db = resync - mddev->resync_mark_cnt;
3907 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3908 }
3909 
3910 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3911 
3912 static ssize_t
3913 sync_completed_show(mddev_t *mddev, char *page)
3914 {
3915 	unsigned long max_sectors, resync;
3916 
3917 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3918 		return sprintf(page, "none\n");
3919 
3920 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3921 		max_sectors = mddev->resync_max_sectors;
3922 	else
3923 		max_sectors = mddev->dev_sectors;
3924 
3925 	resync = mddev->curr_resync_completed;
3926 	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
3927 }
3928 
3929 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3930 
3931 static ssize_t
3932 min_sync_show(mddev_t *mddev, char *page)
3933 {
3934 	return sprintf(page, "%llu\n",
3935 		       (unsigned long long)mddev->resync_min);
3936 }
3937 static ssize_t
3938 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3939 {
3940 	unsigned long long min;
3941 	if (strict_strtoull(buf, 10, &min))
3942 		return -EINVAL;
3943 	if (min > mddev->resync_max)
3944 		return -EINVAL;
3945 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3946 		return -EBUSY;
3947 
3948 	/* Must be a multiple of chunk_size */
3949 	if (mddev->chunk_sectors) {
3950 		sector_t temp = min;
3951 		if (sector_div(temp, mddev->chunk_sectors))
3952 			return -EINVAL;
3953 	}
3954 	mddev->resync_min = min;
3955 
3956 	return len;
3957 }
3958 
3959 static struct md_sysfs_entry md_min_sync =
3960 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3961 
3962 static ssize_t
3963 max_sync_show(mddev_t *mddev, char *page)
3964 {
3965 	if (mddev->resync_max == MaxSector)
3966 		return sprintf(page, "max\n");
3967 	else
3968 		return sprintf(page, "%llu\n",
3969 			       (unsigned long long)mddev->resync_max);
3970 }
3971 static ssize_t
3972 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3973 {
3974 	if (strncmp(buf, "max", 3) == 0)
3975 		mddev->resync_max = MaxSector;
3976 	else {
3977 		unsigned long long max;
3978 		if (strict_strtoull(buf, 10, &max))
3979 			return -EINVAL;
3980 		if (max < mddev->resync_min)
3981 			return -EINVAL;
3982 		if (max < mddev->resync_max &&
3983 		    mddev->ro == 0 &&
3984 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3985 			return -EBUSY;
3986 
3987 		/* Must be a multiple of chunk_size */
3988 		if (mddev->chunk_sectors) {
3989 			sector_t temp = max;
3990 			if (sector_div(temp, mddev->chunk_sectors))
3991 				return -EINVAL;
3992 		}
3993 		mddev->resync_max = max;
3994 	}
3995 	wake_up(&mddev->recovery_wait);
3996 	return len;
3997 }
3998 
3999 static struct md_sysfs_entry md_max_sync =
4000 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4001 
4002 static ssize_t
4003 suspend_lo_show(mddev_t *mddev, char *page)
4004 {
4005 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4006 }
4007 
4008 static ssize_t
4009 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
4010 {
4011 	char *e;
4012 	unsigned long long new = simple_strtoull(buf, &e, 10);
4013 
4014 	if (mddev->pers == NULL ||
4015 	    mddev->pers->quiesce == NULL)
4016 		return -EINVAL;
4017 	if (buf == e || (*e && *e != '\n'))
4018 		return -EINVAL;
4019 	if (new >= mddev->suspend_hi ||
4020 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
4021 		mddev->suspend_lo = new;
4022 		mddev->pers->quiesce(mddev, 2);
4023 		return len;
4024 	} else
4025 		return -EINVAL;
4026 }
4027 static struct md_sysfs_entry md_suspend_lo =
4028 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4029 
4030 
4031 static ssize_t
4032 suspend_hi_show(mddev_t *mddev, char *page)
4033 {
4034 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4035 }
4036 
4037 static ssize_t
4038 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
4039 {
4040 	char *e;
4041 	unsigned long long new = simple_strtoull(buf, &e, 10);
4042 
4043 	if (mddev->pers == NULL ||
4044 	    mddev->pers->quiesce == NULL)
4045 		return -EINVAL;
4046 	if (buf == e || (*e && *e != '\n'))
4047 		return -EINVAL;
4048 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
4049 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
4050 		mddev->suspend_hi = new;
4051 		mddev->pers->quiesce(mddev, 1);
4052 		mddev->pers->quiesce(mddev, 0);
4053 		return len;
4054 	} else
4055 		return -EINVAL;
4056 }
4057 static struct md_sysfs_entry md_suspend_hi =
4058 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4059 
4060 static ssize_t
4061 reshape_position_show(mddev_t *mddev, char *page)
4062 {
4063 	if (mddev->reshape_position != MaxSector)
4064 		return sprintf(page, "%llu\n",
4065 			       (unsigned long long)mddev->reshape_position);
4066 	strcpy(page, "none\n");
4067 	return 5;
4068 }
4069 
4070 static ssize_t
4071 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
4072 {
4073 	char *e;
4074 	unsigned long long new = simple_strtoull(buf, &e, 10);
4075 	if (mddev->pers)
4076 		return -EBUSY;
4077 	if (buf == e || (*e && *e != '\n'))
4078 		return -EINVAL;
4079 	mddev->reshape_position = new;
4080 	mddev->delta_disks = 0;
4081 	mddev->new_level = mddev->level;
4082 	mddev->new_layout = mddev->layout;
4083 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4084 	return len;
4085 }
4086 
4087 static struct md_sysfs_entry md_reshape_position =
4088 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4089        reshape_position_store);
4090 
4091 static ssize_t
4092 array_size_show(mddev_t *mddev, char *page)
4093 {
4094 	if (mddev->external_size)
4095 		return sprintf(page, "%llu\n",
4096 			       (unsigned long long)mddev->array_sectors/2);
4097 	else
4098 		return sprintf(page, "default\n");
4099 }
4100 
4101 static ssize_t
4102 array_size_store(mddev_t *mddev, const char *buf, size_t len)
4103 {
4104 	sector_t sectors;
4105 
4106 	if (strncmp(buf, "default", 7) == 0) {
4107 		if (mddev->pers)
4108 			sectors = mddev->pers->size(mddev, 0, 0);
4109 		else
4110 			sectors = mddev->array_sectors;
4111 
4112 		mddev->external_size = 0;
4113 	} else {
4114 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4115 			return -EINVAL;
4116 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4117 			return -E2BIG;
4118 
4119 		mddev->external_size = 1;
4120 	}
4121 
4122 	mddev->array_sectors = sectors;
4123 	set_capacity(mddev->gendisk, mddev->array_sectors);
4124 	if (mddev->pers)
4125 		revalidate_disk(mddev->gendisk);
4126 
4127 	return len;
4128 }
4129 
4130 static struct md_sysfs_entry md_array_size =
4131 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4132        array_size_store);
4133 
4134 static struct attribute *md_default_attrs[] = {
4135 	&md_level.attr,
4136 	&md_layout.attr,
4137 	&md_raid_disks.attr,
4138 	&md_chunk_size.attr,
4139 	&md_size.attr,
4140 	&md_resync_start.attr,
4141 	&md_metadata.attr,
4142 	&md_new_device.attr,
4143 	&md_safe_delay.attr,
4144 	&md_array_state.attr,
4145 	&md_reshape_position.attr,
4146 	&md_array_size.attr,
4147 	&max_corr_read_errors.attr,
4148 	NULL,
4149 };
4150 
4151 static struct attribute *md_redundancy_attrs[] = {
4152 	&md_scan_mode.attr,
4153 	&md_mismatches.attr,
4154 	&md_sync_min.attr,
4155 	&md_sync_max.attr,
4156 	&md_sync_speed.attr,
4157 	&md_sync_force_parallel.attr,
4158 	&md_sync_completed.attr,
4159 	&md_min_sync.attr,
4160 	&md_max_sync.attr,
4161 	&md_suspend_lo.attr,
4162 	&md_suspend_hi.attr,
4163 	&md_bitmap.attr,
4164 	&md_degraded.attr,
4165 	NULL,
4166 };
4167 static struct attribute_group md_redundancy_group = {
4168 	.name = NULL,
4169 	.attrs = md_redundancy_attrs,
4170 };
4171 
4172 
4173 static ssize_t
4174 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4175 {
4176 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4177 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4178 	ssize_t rv;
4179 
4180 	if (!entry->show)
4181 		return -EIO;
4182 	rv = mddev_lock(mddev);
4183 	if (!rv) {
4184 		rv = entry->show(mddev, page);
4185 		mddev_unlock(mddev);
4186 	}
4187 	return rv;
4188 }
4189 
4190 static ssize_t
4191 md_attr_store(struct kobject *kobj, struct attribute *attr,
4192 	      const char *page, size_t length)
4193 {
4194 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4195 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4196 	ssize_t rv;
4197 
4198 	if (!entry->store)
4199 		return -EIO;
4200 	if (!capable(CAP_SYS_ADMIN))
4201 		return -EACCES;
4202 	rv = mddev_lock(mddev);
4203 	if (mddev->hold_active == UNTIL_IOCTL)
4204 		mddev->hold_active = 0;
4205 	if (!rv) {
4206 		rv = entry->store(mddev, page, length);
4207 		mddev_unlock(mddev);
4208 	}
4209 	return rv;
4210 }
4211 
4212 static void md_free(struct kobject *ko)
4213 {
4214 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
4215 
4216 	if (mddev->sysfs_state)
4217 		sysfs_put(mddev->sysfs_state);
4218 
4219 	if (mddev->gendisk) {
4220 		del_gendisk(mddev->gendisk);
4221 		put_disk(mddev->gendisk);
4222 	}
4223 	if (mddev->queue)
4224 		blk_cleanup_queue(mddev->queue);
4225 
4226 	kfree(mddev);
4227 }
4228 
4229 static const struct sysfs_ops md_sysfs_ops = {
4230 	.show	= md_attr_show,
4231 	.store	= md_attr_store,
4232 };
4233 static struct kobj_type md_ktype = {
4234 	.release	= md_free,
4235 	.sysfs_ops	= &md_sysfs_ops,
4236 	.default_attrs	= md_default_attrs,
4237 };
4238 
4239 int mdp_major = 0;
4240 
4241 static void mddev_delayed_delete(struct work_struct *ws)
4242 {
4243 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
4244 
4245 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4246 	kobject_del(&mddev->kobj);
4247 	kobject_put(&mddev->kobj);
4248 }
4249 
4250 static int md_alloc(dev_t dev, char *name)
4251 {
4252 	static DEFINE_MUTEX(disks_mutex);
4253 	mddev_t *mddev = mddev_find(dev);
4254 	struct gendisk *disk;
4255 	int partitioned;
4256 	int shift;
4257 	int unit;
4258 	int error;
4259 
4260 	if (!mddev)
4261 		return -ENODEV;
4262 
4263 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4264 	shift = partitioned ? MdpMinorShift : 0;
4265 	unit = MINOR(mddev->unit) >> shift;
4266 
4267 	/* wait for any previous instance of this device to be
4268 	 * completely removed (mddev_delayed_delete).
4269 	 */
4270 	flush_workqueue(md_misc_wq);
4271 
4272 	mutex_lock(&disks_mutex);
4273 	error = -EEXIST;
4274 	if (mddev->gendisk)
4275 		goto abort;
4276 
4277 	if (name) {
4278 		/* Need to ensure that 'name' is not a duplicate.
4279 		 */
4280 		mddev_t *mddev2;
4281 		spin_lock(&all_mddevs_lock);
4282 
4283 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4284 			if (mddev2->gendisk &&
4285 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4286 				spin_unlock(&all_mddevs_lock);
4287 				goto abort;
4288 			}
4289 		spin_unlock(&all_mddevs_lock);
4290 	}
4291 
4292 	error = -ENOMEM;
4293 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4294 	if (!mddev->queue)
4295 		goto abort;
4296 	mddev->queue->queuedata = mddev;
4297 
4298 	blk_queue_make_request(mddev->queue, md_make_request);
4299 
4300 	disk = alloc_disk(1 << shift);
4301 	if (!disk) {
4302 		blk_cleanup_queue(mddev->queue);
4303 		mddev->queue = NULL;
4304 		goto abort;
4305 	}
4306 	disk->major = MAJOR(mddev->unit);
4307 	disk->first_minor = unit << shift;
4308 	if (name)
4309 		strcpy(disk->disk_name, name);
4310 	else if (partitioned)
4311 		sprintf(disk->disk_name, "md_d%d", unit);
4312 	else
4313 		sprintf(disk->disk_name, "md%d", unit);
4314 	disk->fops = &md_fops;
4315 	disk->private_data = mddev;
4316 	disk->queue = mddev->queue;
4317 	/* Allow extended partitions.  This makes the
4318 	 * 'mdp' device redundant, but we can't really
4319 	 * remove it now.
4320 	 */
4321 	disk->flags |= GENHD_FL_EXT_DEVT;
4322 	add_disk(disk);
4323 	mddev->gendisk = disk;
4324 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4325 				     &disk_to_dev(disk)->kobj, "%s", "md");
4326 	if (error) {
4327 		/* This isn't possible, but as kobject_init_and_add is marked
4328 		 * __must_check, we must do something with the result
4329 		 */
4330 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4331 		       disk->disk_name);
4332 		error = 0;
4333 	}
4334 	if (mddev->kobj.sd &&
4335 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4336 		printk(KERN_DEBUG "pointless warning\n");
4337 
4338 	blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4339  abort:
4340 	mutex_unlock(&disks_mutex);
4341 	if (!error && mddev->kobj.sd) {
4342 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4343 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4344 	}
4345 	mddev_put(mddev);
4346 	return error;
4347 }
4348 
4349 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4350 {
4351 	md_alloc(dev, NULL);
4352 	return NULL;
4353 }
4354 
4355 static int add_named_array(const char *val, struct kernel_param *kp)
4356 {
4357 	/* val must be "md_*" where * is not all digits.
4358 	 * We allocate an array with a large free minor number, and
4359 	 * set the name to val.  val must not already be an active name.
4360 	 */
4361 	int len = strlen(val);
4362 	char buf[DISK_NAME_LEN];
4363 
4364 	while (len && val[len-1] == '\n')
4365 		len--;
4366 	if (len >= DISK_NAME_LEN)
4367 		return -E2BIG;
4368 	strlcpy(buf, val, len+1);
4369 	if (strncmp(buf, "md_", 3) != 0)
4370 		return -EINVAL;
4371 	return md_alloc(0, buf);
4372 }
4373 
4374 static void md_safemode_timeout(unsigned long data)
4375 {
4376 	mddev_t *mddev = (mddev_t *) data;
4377 
4378 	if (!atomic_read(&mddev->writes_pending)) {
4379 		mddev->safemode = 1;
4380 		if (mddev->external)
4381 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4382 	}
4383 	md_wakeup_thread(mddev->thread);
4384 }
4385 
4386 static int start_dirty_degraded;
4387 
4388 int md_run(mddev_t *mddev)
4389 {
4390 	int err;
4391 	mdk_rdev_t *rdev;
4392 	struct mdk_personality *pers;
4393 
4394 	if (list_empty(&mddev->disks))
4395 		/* cannot run an array with no devices.. */
4396 		return -EINVAL;
4397 
4398 	if (mddev->pers)
4399 		return -EBUSY;
4400 	/* Cannot run until previous stop completes properly */
4401 	if (mddev->sysfs_active)
4402 		return -EBUSY;
4403 
4404 	/*
4405 	 * Analyze all RAID superblock(s)
4406 	 */
4407 	if (!mddev->raid_disks) {
4408 		if (!mddev->persistent)
4409 			return -EINVAL;
4410 		analyze_sbs(mddev);
4411 	}
4412 
4413 	if (mddev->level != LEVEL_NONE)
4414 		request_module("md-level-%d", mddev->level);
4415 	else if (mddev->clevel[0])
4416 		request_module("md-%s", mddev->clevel);
4417 
4418 	/*
4419 	 * Drop all container device buffers, from now on
4420 	 * the only valid external interface is through the md
4421 	 * device.
4422 	 */
4423 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4424 		if (test_bit(Faulty, &rdev->flags))
4425 			continue;
4426 		sync_blockdev(rdev->bdev);
4427 		invalidate_bdev(rdev->bdev);
4428 
4429 		/* perform some consistency tests on the device.
4430 		 * We don't want the data to overlap the metadata,
4431 		 * Internal Bitmap issues have been handled elsewhere.
4432 		 */
4433 		if (rdev->data_offset < rdev->sb_start) {
4434 			if (mddev->dev_sectors &&
4435 			    rdev->data_offset + mddev->dev_sectors
4436 			    > rdev->sb_start) {
4437 				printk("md: %s: data overlaps metadata\n",
4438 				       mdname(mddev));
4439 				return -EINVAL;
4440 			}
4441 		} else {
4442 			if (rdev->sb_start + rdev->sb_size/512
4443 			    > rdev->data_offset) {
4444 				printk("md: %s: metadata overlaps data\n",
4445 				       mdname(mddev));
4446 				return -EINVAL;
4447 			}
4448 		}
4449 		sysfs_notify_dirent_safe(rdev->sysfs_state);
4450 	}
4451 
4452 	if (mddev->bio_set == NULL)
4453 		mddev->bio_set = bioset_create(BIO_POOL_SIZE, sizeof(mddev));
4454 
4455 	spin_lock(&pers_lock);
4456 	pers = find_pers(mddev->level, mddev->clevel);
4457 	if (!pers || !try_module_get(pers->owner)) {
4458 		spin_unlock(&pers_lock);
4459 		if (mddev->level != LEVEL_NONE)
4460 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4461 			       mddev->level);
4462 		else
4463 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4464 			       mddev->clevel);
4465 		return -EINVAL;
4466 	}
4467 	mddev->pers = pers;
4468 	spin_unlock(&pers_lock);
4469 	if (mddev->level != pers->level) {
4470 		mddev->level = pers->level;
4471 		mddev->new_level = pers->level;
4472 	}
4473 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4474 
4475 	if (mddev->reshape_position != MaxSector &&
4476 	    pers->start_reshape == NULL) {
4477 		/* This personality cannot handle reshaping... */
4478 		mddev->pers = NULL;
4479 		module_put(pers->owner);
4480 		return -EINVAL;
4481 	}
4482 
4483 	if (pers->sync_request) {
4484 		/* Warn if this is a potentially silly
4485 		 * configuration.
4486 		 */
4487 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4488 		mdk_rdev_t *rdev2;
4489 		int warned = 0;
4490 
4491 		list_for_each_entry(rdev, &mddev->disks, same_set)
4492 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4493 				if (rdev < rdev2 &&
4494 				    rdev->bdev->bd_contains ==
4495 				    rdev2->bdev->bd_contains) {
4496 					printk(KERN_WARNING
4497 					       "%s: WARNING: %s appears to be"
4498 					       " on the same physical disk as"
4499 					       " %s.\n",
4500 					       mdname(mddev),
4501 					       bdevname(rdev->bdev,b),
4502 					       bdevname(rdev2->bdev,b2));
4503 					warned = 1;
4504 				}
4505 			}
4506 
4507 		if (warned)
4508 			printk(KERN_WARNING
4509 			       "True protection against single-disk"
4510 			       " failure might be compromised.\n");
4511 	}
4512 
4513 	mddev->recovery = 0;
4514 	/* may be over-ridden by personality */
4515 	mddev->resync_max_sectors = mddev->dev_sectors;
4516 
4517 	mddev->ok_start_degraded = start_dirty_degraded;
4518 
4519 	if (start_readonly && mddev->ro == 0)
4520 		mddev->ro = 2; /* read-only, but switch on first write */
4521 
4522 	err = mddev->pers->run(mddev);
4523 	if (err)
4524 		printk(KERN_ERR "md: pers->run() failed ...\n");
4525 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4526 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4527 			  " but 'external_size' not in effect?\n", __func__);
4528 		printk(KERN_ERR
4529 		       "md: invalid array_size %llu > default size %llu\n",
4530 		       (unsigned long long)mddev->array_sectors / 2,
4531 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4532 		err = -EINVAL;
4533 		mddev->pers->stop(mddev);
4534 	}
4535 	if (err == 0 && mddev->pers->sync_request) {
4536 		err = bitmap_create(mddev);
4537 		if (err) {
4538 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4539 			       mdname(mddev), err);
4540 			mddev->pers->stop(mddev);
4541 		}
4542 	}
4543 	if (err) {
4544 		module_put(mddev->pers->owner);
4545 		mddev->pers = NULL;
4546 		bitmap_destroy(mddev);
4547 		return err;
4548 	}
4549 	if (mddev->pers->sync_request) {
4550 		if (mddev->kobj.sd &&
4551 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4552 			printk(KERN_WARNING
4553 			       "md: cannot register extra attributes for %s\n",
4554 			       mdname(mddev));
4555 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
4556 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4557 		mddev->ro = 0;
4558 
4559  	atomic_set(&mddev->writes_pending,0);
4560 	atomic_set(&mddev->max_corr_read_errors,
4561 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
4562 	mddev->safemode = 0;
4563 	mddev->safemode_timer.function = md_safemode_timeout;
4564 	mddev->safemode_timer.data = (unsigned long) mddev;
4565 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4566 	mddev->in_sync = 1;
4567 
4568 	list_for_each_entry(rdev, &mddev->disks, same_set)
4569 		if (rdev->raid_disk >= 0) {
4570 			char nm[20];
4571 			sprintf(nm, "rd%d", rdev->raid_disk);
4572 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
4573 				/* failure here is OK */;
4574 		}
4575 
4576 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4577 
4578 	if (mddev->flags)
4579 		md_update_sb(mddev, 0);
4580 
4581 	md_wakeup_thread(mddev->thread);
4582 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4583 
4584 	md_new_event(mddev);
4585 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4586 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4587 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4588 	return 0;
4589 }
4590 EXPORT_SYMBOL_GPL(md_run);
4591 
4592 static int do_md_run(mddev_t *mddev)
4593 {
4594 	int err;
4595 
4596 	err = md_run(mddev);
4597 	if (err)
4598 		goto out;
4599 	err = bitmap_load(mddev);
4600 	if (err) {
4601 		bitmap_destroy(mddev);
4602 		goto out;
4603 	}
4604 	set_capacity(mddev->gendisk, mddev->array_sectors);
4605 	revalidate_disk(mddev->gendisk);
4606 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4607 out:
4608 	return err;
4609 }
4610 
4611 static int restart_array(mddev_t *mddev)
4612 {
4613 	struct gendisk *disk = mddev->gendisk;
4614 
4615 	/* Complain if it has no devices */
4616 	if (list_empty(&mddev->disks))
4617 		return -ENXIO;
4618 	if (!mddev->pers)
4619 		return -EINVAL;
4620 	if (!mddev->ro)
4621 		return -EBUSY;
4622 	mddev->safemode = 0;
4623 	mddev->ro = 0;
4624 	set_disk_ro(disk, 0);
4625 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4626 		mdname(mddev));
4627 	/* Kick recovery or resync if necessary */
4628 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4629 	md_wakeup_thread(mddev->thread);
4630 	md_wakeup_thread(mddev->sync_thread);
4631 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4632 	return 0;
4633 }
4634 
4635 /* similar to deny_write_access, but accounts for our holding a reference
4636  * to the file ourselves */
4637 static int deny_bitmap_write_access(struct file * file)
4638 {
4639 	struct inode *inode = file->f_mapping->host;
4640 
4641 	spin_lock(&inode->i_lock);
4642 	if (atomic_read(&inode->i_writecount) > 1) {
4643 		spin_unlock(&inode->i_lock);
4644 		return -ETXTBSY;
4645 	}
4646 	atomic_set(&inode->i_writecount, -1);
4647 	spin_unlock(&inode->i_lock);
4648 
4649 	return 0;
4650 }
4651 
4652 void restore_bitmap_write_access(struct file *file)
4653 {
4654 	struct inode *inode = file->f_mapping->host;
4655 
4656 	spin_lock(&inode->i_lock);
4657 	atomic_set(&inode->i_writecount, 1);
4658 	spin_unlock(&inode->i_lock);
4659 }
4660 
4661 static void md_clean(mddev_t *mddev)
4662 {
4663 	mddev->array_sectors = 0;
4664 	mddev->external_size = 0;
4665 	mddev->dev_sectors = 0;
4666 	mddev->raid_disks = 0;
4667 	mddev->recovery_cp = 0;
4668 	mddev->resync_min = 0;
4669 	mddev->resync_max = MaxSector;
4670 	mddev->reshape_position = MaxSector;
4671 	mddev->external = 0;
4672 	mddev->persistent = 0;
4673 	mddev->level = LEVEL_NONE;
4674 	mddev->clevel[0] = 0;
4675 	mddev->flags = 0;
4676 	mddev->ro = 0;
4677 	mddev->metadata_type[0] = 0;
4678 	mddev->chunk_sectors = 0;
4679 	mddev->ctime = mddev->utime = 0;
4680 	mddev->layout = 0;
4681 	mddev->max_disks = 0;
4682 	mddev->events = 0;
4683 	mddev->can_decrease_events = 0;
4684 	mddev->delta_disks = 0;
4685 	mddev->new_level = LEVEL_NONE;
4686 	mddev->new_layout = 0;
4687 	mddev->new_chunk_sectors = 0;
4688 	mddev->curr_resync = 0;
4689 	mddev->resync_mismatches = 0;
4690 	mddev->suspend_lo = mddev->suspend_hi = 0;
4691 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
4692 	mddev->recovery = 0;
4693 	mddev->in_sync = 0;
4694 	mddev->degraded = 0;
4695 	mddev->safemode = 0;
4696 	mddev->bitmap_info.offset = 0;
4697 	mddev->bitmap_info.default_offset = 0;
4698 	mddev->bitmap_info.chunksize = 0;
4699 	mddev->bitmap_info.daemon_sleep = 0;
4700 	mddev->bitmap_info.max_write_behind = 0;
4701 	mddev->plug = NULL;
4702 }
4703 
4704 void md_stop_writes(mddev_t *mddev)
4705 {
4706 	if (mddev->sync_thread) {
4707 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4708 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4709 		md_unregister_thread(mddev->sync_thread);
4710 		mddev->sync_thread = NULL;
4711 	}
4712 
4713 	del_timer_sync(&mddev->safemode_timer);
4714 
4715 	bitmap_flush(mddev);
4716 	md_super_wait(mddev);
4717 
4718 	if (!mddev->in_sync || mddev->flags) {
4719 		/* mark array as shutdown cleanly */
4720 		mddev->in_sync = 1;
4721 		md_update_sb(mddev, 1);
4722 	}
4723 }
4724 EXPORT_SYMBOL_GPL(md_stop_writes);
4725 
4726 void md_stop(mddev_t *mddev)
4727 {
4728 	mddev->pers->stop(mddev);
4729 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
4730 		mddev->to_remove = &md_redundancy_group;
4731 	module_put(mddev->pers->owner);
4732 	mddev->pers = NULL;
4733 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4734 }
4735 EXPORT_SYMBOL_GPL(md_stop);
4736 
4737 static int md_set_readonly(mddev_t *mddev, int is_open)
4738 {
4739 	int err = 0;
4740 	mutex_lock(&mddev->open_mutex);
4741 	if (atomic_read(&mddev->openers) > is_open) {
4742 		printk("md: %s still in use.\n",mdname(mddev));
4743 		err = -EBUSY;
4744 		goto out;
4745 	}
4746 	if (mddev->pers) {
4747 		md_stop_writes(mddev);
4748 
4749 		err  = -ENXIO;
4750 		if (mddev->ro==1)
4751 			goto out;
4752 		mddev->ro = 1;
4753 		set_disk_ro(mddev->gendisk, 1);
4754 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4755 		sysfs_notify_dirent_safe(mddev->sysfs_state);
4756 		err = 0;
4757 	}
4758 out:
4759 	mutex_unlock(&mddev->open_mutex);
4760 	return err;
4761 }
4762 
4763 /* mode:
4764  *   0 - completely stop and dis-assemble array
4765  *   2 - stop but do not disassemble array
4766  */
4767 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4768 {
4769 	struct gendisk *disk = mddev->gendisk;
4770 	mdk_rdev_t *rdev;
4771 
4772 	mutex_lock(&mddev->open_mutex);
4773 	if (atomic_read(&mddev->openers) > is_open ||
4774 	    mddev->sysfs_active) {
4775 		printk("md: %s still in use.\n",mdname(mddev));
4776 		mutex_unlock(&mddev->open_mutex);
4777 		return -EBUSY;
4778 	}
4779 
4780 	if (mddev->pers) {
4781 		if (mddev->ro)
4782 			set_disk_ro(disk, 0);
4783 
4784 		md_stop_writes(mddev);
4785 		md_stop(mddev);
4786 		mddev->queue->merge_bvec_fn = NULL;
4787 		mddev->queue->unplug_fn = NULL;
4788 		mddev->queue->backing_dev_info.congested_fn = NULL;
4789 
4790 		/* tell userspace to handle 'inactive' */
4791 		sysfs_notify_dirent_safe(mddev->sysfs_state);
4792 
4793 		list_for_each_entry(rdev, &mddev->disks, same_set)
4794 			if (rdev->raid_disk >= 0) {
4795 				char nm[20];
4796 				sprintf(nm, "rd%d", rdev->raid_disk);
4797 				sysfs_remove_link(&mddev->kobj, nm);
4798 			}
4799 
4800 		set_capacity(disk, 0);
4801 		mutex_unlock(&mddev->open_mutex);
4802 		revalidate_disk(disk);
4803 
4804 		if (mddev->ro)
4805 			mddev->ro = 0;
4806 	} else
4807 		mutex_unlock(&mddev->open_mutex);
4808 	/*
4809 	 * Free resources if final stop
4810 	 */
4811 	if (mode == 0) {
4812 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4813 
4814 		bitmap_destroy(mddev);
4815 		if (mddev->bitmap_info.file) {
4816 			restore_bitmap_write_access(mddev->bitmap_info.file);
4817 			fput(mddev->bitmap_info.file);
4818 			mddev->bitmap_info.file = NULL;
4819 		}
4820 		mddev->bitmap_info.offset = 0;
4821 
4822 		export_array(mddev);
4823 
4824 		md_clean(mddev);
4825 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4826 		if (mddev->hold_active == UNTIL_STOP)
4827 			mddev->hold_active = 0;
4828 	}
4829 	blk_integrity_unregister(disk);
4830 	md_new_event(mddev);
4831 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4832 	return 0;
4833 }
4834 
4835 #ifndef MODULE
4836 static void autorun_array(mddev_t *mddev)
4837 {
4838 	mdk_rdev_t *rdev;
4839 	int err;
4840 
4841 	if (list_empty(&mddev->disks))
4842 		return;
4843 
4844 	printk(KERN_INFO "md: running: ");
4845 
4846 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4847 		char b[BDEVNAME_SIZE];
4848 		printk("<%s>", bdevname(rdev->bdev,b));
4849 	}
4850 	printk("\n");
4851 
4852 	err = do_md_run(mddev);
4853 	if (err) {
4854 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4855 		do_md_stop(mddev, 0, 0);
4856 	}
4857 }
4858 
4859 /*
4860  * lets try to run arrays based on all disks that have arrived
4861  * until now. (those are in pending_raid_disks)
4862  *
4863  * the method: pick the first pending disk, collect all disks with
4864  * the same UUID, remove all from the pending list and put them into
4865  * the 'same_array' list. Then order this list based on superblock
4866  * update time (freshest comes first), kick out 'old' disks and
4867  * compare superblocks. If everything's fine then run it.
4868  *
4869  * If "unit" is allocated, then bump its reference count
4870  */
4871 static void autorun_devices(int part)
4872 {
4873 	mdk_rdev_t *rdev0, *rdev, *tmp;
4874 	mddev_t *mddev;
4875 	char b[BDEVNAME_SIZE];
4876 
4877 	printk(KERN_INFO "md: autorun ...\n");
4878 	while (!list_empty(&pending_raid_disks)) {
4879 		int unit;
4880 		dev_t dev;
4881 		LIST_HEAD(candidates);
4882 		rdev0 = list_entry(pending_raid_disks.next,
4883 					 mdk_rdev_t, same_set);
4884 
4885 		printk(KERN_INFO "md: considering %s ...\n",
4886 			bdevname(rdev0->bdev,b));
4887 		INIT_LIST_HEAD(&candidates);
4888 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4889 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4890 				printk(KERN_INFO "md:  adding %s ...\n",
4891 					bdevname(rdev->bdev,b));
4892 				list_move(&rdev->same_set, &candidates);
4893 			}
4894 		/*
4895 		 * now we have a set of devices, with all of them having
4896 		 * mostly sane superblocks. It's time to allocate the
4897 		 * mddev.
4898 		 */
4899 		if (part) {
4900 			dev = MKDEV(mdp_major,
4901 				    rdev0->preferred_minor << MdpMinorShift);
4902 			unit = MINOR(dev) >> MdpMinorShift;
4903 		} else {
4904 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4905 			unit = MINOR(dev);
4906 		}
4907 		if (rdev0->preferred_minor != unit) {
4908 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4909 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4910 			break;
4911 		}
4912 
4913 		md_probe(dev, NULL, NULL);
4914 		mddev = mddev_find(dev);
4915 		if (!mddev || !mddev->gendisk) {
4916 			if (mddev)
4917 				mddev_put(mddev);
4918 			printk(KERN_ERR
4919 				"md: cannot allocate memory for md drive.\n");
4920 			break;
4921 		}
4922 		if (mddev_lock(mddev))
4923 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4924 			       mdname(mddev));
4925 		else if (mddev->raid_disks || mddev->major_version
4926 			 || !list_empty(&mddev->disks)) {
4927 			printk(KERN_WARNING
4928 				"md: %s already running, cannot run %s\n",
4929 				mdname(mddev), bdevname(rdev0->bdev,b));
4930 			mddev_unlock(mddev);
4931 		} else {
4932 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4933 			mddev->persistent = 1;
4934 			rdev_for_each_list(rdev, tmp, &candidates) {
4935 				list_del_init(&rdev->same_set);
4936 				if (bind_rdev_to_array(rdev, mddev))
4937 					export_rdev(rdev);
4938 			}
4939 			autorun_array(mddev);
4940 			mddev_unlock(mddev);
4941 		}
4942 		/* on success, candidates will be empty, on error
4943 		 * it won't...
4944 		 */
4945 		rdev_for_each_list(rdev, tmp, &candidates) {
4946 			list_del_init(&rdev->same_set);
4947 			export_rdev(rdev);
4948 		}
4949 		mddev_put(mddev);
4950 	}
4951 	printk(KERN_INFO "md: ... autorun DONE.\n");
4952 }
4953 #endif /* !MODULE */
4954 
4955 static int get_version(void __user * arg)
4956 {
4957 	mdu_version_t ver;
4958 
4959 	ver.major = MD_MAJOR_VERSION;
4960 	ver.minor = MD_MINOR_VERSION;
4961 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4962 
4963 	if (copy_to_user(arg, &ver, sizeof(ver)))
4964 		return -EFAULT;
4965 
4966 	return 0;
4967 }
4968 
4969 static int get_array_info(mddev_t * mddev, void __user * arg)
4970 {
4971 	mdu_array_info_t info;
4972 	int nr,working,insync,failed,spare;
4973 	mdk_rdev_t *rdev;
4974 
4975 	nr=working=insync=failed=spare=0;
4976 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4977 		nr++;
4978 		if (test_bit(Faulty, &rdev->flags))
4979 			failed++;
4980 		else {
4981 			working++;
4982 			if (test_bit(In_sync, &rdev->flags))
4983 				insync++;
4984 			else
4985 				spare++;
4986 		}
4987 	}
4988 
4989 	info.major_version = mddev->major_version;
4990 	info.minor_version = mddev->minor_version;
4991 	info.patch_version = MD_PATCHLEVEL_VERSION;
4992 	info.ctime         = mddev->ctime;
4993 	info.level         = mddev->level;
4994 	info.size          = mddev->dev_sectors / 2;
4995 	if (info.size != mddev->dev_sectors / 2) /* overflow */
4996 		info.size = -1;
4997 	info.nr_disks      = nr;
4998 	info.raid_disks    = mddev->raid_disks;
4999 	info.md_minor      = mddev->md_minor;
5000 	info.not_persistent= !mddev->persistent;
5001 
5002 	info.utime         = mddev->utime;
5003 	info.state         = 0;
5004 	if (mddev->in_sync)
5005 		info.state = (1<<MD_SB_CLEAN);
5006 	if (mddev->bitmap && mddev->bitmap_info.offset)
5007 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5008 	info.active_disks  = insync;
5009 	info.working_disks = working;
5010 	info.failed_disks  = failed;
5011 	info.spare_disks   = spare;
5012 
5013 	info.layout        = mddev->layout;
5014 	info.chunk_size    = mddev->chunk_sectors << 9;
5015 
5016 	if (copy_to_user(arg, &info, sizeof(info)))
5017 		return -EFAULT;
5018 
5019 	return 0;
5020 }
5021 
5022 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
5023 {
5024 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5025 	char *ptr, *buf = NULL;
5026 	int err = -ENOMEM;
5027 
5028 	if (md_allow_write(mddev))
5029 		file = kmalloc(sizeof(*file), GFP_NOIO);
5030 	else
5031 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5032 
5033 	if (!file)
5034 		goto out;
5035 
5036 	/* bitmap disabled, zero the first byte and copy out */
5037 	if (!mddev->bitmap || !mddev->bitmap->file) {
5038 		file->pathname[0] = '\0';
5039 		goto copy_out;
5040 	}
5041 
5042 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5043 	if (!buf)
5044 		goto out;
5045 
5046 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
5047 	if (IS_ERR(ptr))
5048 		goto out;
5049 
5050 	strcpy(file->pathname, ptr);
5051 
5052 copy_out:
5053 	err = 0;
5054 	if (copy_to_user(arg, file, sizeof(*file)))
5055 		err = -EFAULT;
5056 out:
5057 	kfree(buf);
5058 	kfree(file);
5059 	return err;
5060 }
5061 
5062 static int get_disk_info(mddev_t * mddev, void __user * arg)
5063 {
5064 	mdu_disk_info_t info;
5065 	mdk_rdev_t *rdev;
5066 
5067 	if (copy_from_user(&info, arg, sizeof(info)))
5068 		return -EFAULT;
5069 
5070 	rdev = find_rdev_nr(mddev, info.number);
5071 	if (rdev) {
5072 		info.major = MAJOR(rdev->bdev->bd_dev);
5073 		info.minor = MINOR(rdev->bdev->bd_dev);
5074 		info.raid_disk = rdev->raid_disk;
5075 		info.state = 0;
5076 		if (test_bit(Faulty, &rdev->flags))
5077 			info.state |= (1<<MD_DISK_FAULTY);
5078 		else if (test_bit(In_sync, &rdev->flags)) {
5079 			info.state |= (1<<MD_DISK_ACTIVE);
5080 			info.state |= (1<<MD_DISK_SYNC);
5081 		}
5082 		if (test_bit(WriteMostly, &rdev->flags))
5083 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5084 	} else {
5085 		info.major = info.minor = 0;
5086 		info.raid_disk = -1;
5087 		info.state = (1<<MD_DISK_REMOVED);
5088 	}
5089 
5090 	if (copy_to_user(arg, &info, sizeof(info)))
5091 		return -EFAULT;
5092 
5093 	return 0;
5094 }
5095 
5096 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5097 {
5098 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5099 	mdk_rdev_t *rdev;
5100 	dev_t dev = MKDEV(info->major,info->minor);
5101 
5102 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5103 		return -EOVERFLOW;
5104 
5105 	if (!mddev->raid_disks) {
5106 		int err;
5107 		/* expecting a device which has a superblock */
5108 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5109 		if (IS_ERR(rdev)) {
5110 			printk(KERN_WARNING
5111 				"md: md_import_device returned %ld\n",
5112 				PTR_ERR(rdev));
5113 			return PTR_ERR(rdev);
5114 		}
5115 		if (!list_empty(&mddev->disks)) {
5116 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
5117 							mdk_rdev_t, same_set);
5118 			err = super_types[mddev->major_version]
5119 				.load_super(rdev, rdev0, mddev->minor_version);
5120 			if (err < 0) {
5121 				printk(KERN_WARNING
5122 					"md: %s has different UUID to %s\n",
5123 					bdevname(rdev->bdev,b),
5124 					bdevname(rdev0->bdev,b2));
5125 				export_rdev(rdev);
5126 				return -EINVAL;
5127 			}
5128 		}
5129 		err = bind_rdev_to_array(rdev, mddev);
5130 		if (err)
5131 			export_rdev(rdev);
5132 		return err;
5133 	}
5134 
5135 	/*
5136 	 * add_new_disk can be used once the array is assembled
5137 	 * to add "hot spares".  They must already have a superblock
5138 	 * written
5139 	 */
5140 	if (mddev->pers) {
5141 		int err;
5142 		if (!mddev->pers->hot_add_disk) {
5143 			printk(KERN_WARNING
5144 				"%s: personality does not support diskops!\n",
5145 			       mdname(mddev));
5146 			return -EINVAL;
5147 		}
5148 		if (mddev->persistent)
5149 			rdev = md_import_device(dev, mddev->major_version,
5150 						mddev->minor_version);
5151 		else
5152 			rdev = md_import_device(dev, -1, -1);
5153 		if (IS_ERR(rdev)) {
5154 			printk(KERN_WARNING
5155 				"md: md_import_device returned %ld\n",
5156 				PTR_ERR(rdev));
5157 			return PTR_ERR(rdev);
5158 		}
5159 		/* set saved_raid_disk if appropriate */
5160 		if (!mddev->persistent) {
5161 			if (info->state & (1<<MD_DISK_SYNC)  &&
5162 			    info->raid_disk < mddev->raid_disks)
5163 				rdev->raid_disk = info->raid_disk;
5164 			else
5165 				rdev->raid_disk = -1;
5166 		} else
5167 			super_types[mddev->major_version].
5168 				validate_super(mddev, rdev);
5169 		if (test_bit(In_sync, &rdev->flags))
5170 			rdev->saved_raid_disk = rdev->raid_disk;
5171 		else
5172 			rdev->saved_raid_disk = -1;
5173 
5174 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5175 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5176 			set_bit(WriteMostly, &rdev->flags);
5177 		else
5178 			clear_bit(WriteMostly, &rdev->flags);
5179 
5180 		rdev->raid_disk = -1;
5181 		err = bind_rdev_to_array(rdev, mddev);
5182 		if (!err && !mddev->pers->hot_remove_disk) {
5183 			/* If there is hot_add_disk but no hot_remove_disk
5184 			 * then added disks for geometry changes,
5185 			 * and should be added immediately.
5186 			 */
5187 			super_types[mddev->major_version].
5188 				validate_super(mddev, rdev);
5189 			err = mddev->pers->hot_add_disk(mddev, rdev);
5190 			if (err)
5191 				unbind_rdev_from_array(rdev);
5192 		}
5193 		if (err)
5194 			export_rdev(rdev);
5195 		else
5196 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5197 
5198 		md_update_sb(mddev, 1);
5199 		if (mddev->degraded)
5200 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5201 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5202 		md_wakeup_thread(mddev->thread);
5203 		return err;
5204 	}
5205 
5206 	/* otherwise, add_new_disk is only allowed
5207 	 * for major_version==0 superblocks
5208 	 */
5209 	if (mddev->major_version != 0) {
5210 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5211 		       mdname(mddev));
5212 		return -EINVAL;
5213 	}
5214 
5215 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5216 		int err;
5217 		rdev = md_import_device(dev, -1, 0);
5218 		if (IS_ERR(rdev)) {
5219 			printk(KERN_WARNING
5220 				"md: error, md_import_device() returned %ld\n",
5221 				PTR_ERR(rdev));
5222 			return PTR_ERR(rdev);
5223 		}
5224 		rdev->desc_nr = info->number;
5225 		if (info->raid_disk < mddev->raid_disks)
5226 			rdev->raid_disk = info->raid_disk;
5227 		else
5228 			rdev->raid_disk = -1;
5229 
5230 		if (rdev->raid_disk < mddev->raid_disks)
5231 			if (info->state & (1<<MD_DISK_SYNC))
5232 				set_bit(In_sync, &rdev->flags);
5233 
5234 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5235 			set_bit(WriteMostly, &rdev->flags);
5236 
5237 		if (!mddev->persistent) {
5238 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5239 			rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5240 		} else
5241 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
5242 		rdev->sectors = rdev->sb_start;
5243 
5244 		err = bind_rdev_to_array(rdev, mddev);
5245 		if (err) {
5246 			export_rdev(rdev);
5247 			return err;
5248 		}
5249 	}
5250 
5251 	return 0;
5252 }
5253 
5254 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
5255 {
5256 	char b[BDEVNAME_SIZE];
5257 	mdk_rdev_t *rdev;
5258 
5259 	rdev = find_rdev(mddev, dev);
5260 	if (!rdev)
5261 		return -ENXIO;
5262 
5263 	if (rdev->raid_disk >= 0)
5264 		goto busy;
5265 
5266 	kick_rdev_from_array(rdev);
5267 	md_update_sb(mddev, 1);
5268 	md_new_event(mddev);
5269 
5270 	return 0;
5271 busy:
5272 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5273 		bdevname(rdev->bdev,b), mdname(mddev));
5274 	return -EBUSY;
5275 }
5276 
5277 static int hot_add_disk(mddev_t * mddev, dev_t dev)
5278 {
5279 	char b[BDEVNAME_SIZE];
5280 	int err;
5281 	mdk_rdev_t *rdev;
5282 
5283 	if (!mddev->pers)
5284 		return -ENODEV;
5285 
5286 	if (mddev->major_version != 0) {
5287 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5288 			" version-0 superblocks.\n",
5289 			mdname(mddev));
5290 		return -EINVAL;
5291 	}
5292 	if (!mddev->pers->hot_add_disk) {
5293 		printk(KERN_WARNING
5294 			"%s: personality does not support diskops!\n",
5295 			mdname(mddev));
5296 		return -EINVAL;
5297 	}
5298 
5299 	rdev = md_import_device(dev, -1, 0);
5300 	if (IS_ERR(rdev)) {
5301 		printk(KERN_WARNING
5302 			"md: error, md_import_device() returned %ld\n",
5303 			PTR_ERR(rdev));
5304 		return -EINVAL;
5305 	}
5306 
5307 	if (mddev->persistent)
5308 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
5309 	else
5310 		rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5311 
5312 	rdev->sectors = rdev->sb_start;
5313 
5314 	if (test_bit(Faulty, &rdev->flags)) {
5315 		printk(KERN_WARNING
5316 			"md: can not hot-add faulty %s disk to %s!\n",
5317 			bdevname(rdev->bdev,b), mdname(mddev));
5318 		err = -EINVAL;
5319 		goto abort_export;
5320 	}
5321 	clear_bit(In_sync, &rdev->flags);
5322 	rdev->desc_nr = -1;
5323 	rdev->saved_raid_disk = -1;
5324 	err = bind_rdev_to_array(rdev, mddev);
5325 	if (err)
5326 		goto abort_export;
5327 
5328 	/*
5329 	 * The rest should better be atomic, we can have disk failures
5330 	 * noticed in interrupt contexts ...
5331 	 */
5332 
5333 	rdev->raid_disk = -1;
5334 
5335 	md_update_sb(mddev, 1);
5336 
5337 	/*
5338 	 * Kick recovery, maybe this spare has to be added to the
5339 	 * array immediately.
5340 	 */
5341 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5342 	md_wakeup_thread(mddev->thread);
5343 	md_new_event(mddev);
5344 	return 0;
5345 
5346 abort_export:
5347 	export_rdev(rdev);
5348 	return err;
5349 }
5350 
5351 static int set_bitmap_file(mddev_t *mddev, int fd)
5352 {
5353 	int err;
5354 
5355 	if (mddev->pers) {
5356 		if (!mddev->pers->quiesce)
5357 			return -EBUSY;
5358 		if (mddev->recovery || mddev->sync_thread)
5359 			return -EBUSY;
5360 		/* we should be able to change the bitmap.. */
5361 	}
5362 
5363 
5364 	if (fd >= 0) {
5365 		if (mddev->bitmap)
5366 			return -EEXIST; /* cannot add when bitmap is present */
5367 		mddev->bitmap_info.file = fget(fd);
5368 
5369 		if (mddev->bitmap_info.file == NULL) {
5370 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5371 			       mdname(mddev));
5372 			return -EBADF;
5373 		}
5374 
5375 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5376 		if (err) {
5377 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5378 			       mdname(mddev));
5379 			fput(mddev->bitmap_info.file);
5380 			mddev->bitmap_info.file = NULL;
5381 			return err;
5382 		}
5383 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5384 	} else if (mddev->bitmap == NULL)
5385 		return -ENOENT; /* cannot remove what isn't there */
5386 	err = 0;
5387 	if (mddev->pers) {
5388 		mddev->pers->quiesce(mddev, 1);
5389 		if (fd >= 0) {
5390 			err = bitmap_create(mddev);
5391 			if (!err)
5392 				err = bitmap_load(mddev);
5393 		}
5394 		if (fd < 0 || err) {
5395 			bitmap_destroy(mddev);
5396 			fd = -1; /* make sure to put the file */
5397 		}
5398 		mddev->pers->quiesce(mddev, 0);
5399 	}
5400 	if (fd < 0) {
5401 		if (mddev->bitmap_info.file) {
5402 			restore_bitmap_write_access(mddev->bitmap_info.file);
5403 			fput(mddev->bitmap_info.file);
5404 		}
5405 		mddev->bitmap_info.file = NULL;
5406 	}
5407 
5408 	return err;
5409 }
5410 
5411 /*
5412  * set_array_info is used two different ways
5413  * The original usage is when creating a new array.
5414  * In this usage, raid_disks is > 0 and it together with
5415  *  level, size, not_persistent,layout,chunksize determine the
5416  *  shape of the array.
5417  *  This will always create an array with a type-0.90.0 superblock.
5418  * The newer usage is when assembling an array.
5419  *  In this case raid_disks will be 0, and the major_version field is
5420  *  use to determine which style super-blocks are to be found on the devices.
5421  *  The minor and patch _version numbers are also kept incase the
5422  *  super_block handler wishes to interpret them.
5423  */
5424 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5425 {
5426 
5427 	if (info->raid_disks == 0) {
5428 		/* just setting version number for superblock loading */
5429 		if (info->major_version < 0 ||
5430 		    info->major_version >= ARRAY_SIZE(super_types) ||
5431 		    super_types[info->major_version].name == NULL) {
5432 			/* maybe try to auto-load a module? */
5433 			printk(KERN_INFO
5434 				"md: superblock version %d not known\n",
5435 				info->major_version);
5436 			return -EINVAL;
5437 		}
5438 		mddev->major_version = info->major_version;
5439 		mddev->minor_version = info->minor_version;
5440 		mddev->patch_version = info->patch_version;
5441 		mddev->persistent = !info->not_persistent;
5442 		/* ensure mddev_put doesn't delete this now that there
5443 		 * is some minimal configuration.
5444 		 */
5445 		mddev->ctime         = get_seconds();
5446 		return 0;
5447 	}
5448 	mddev->major_version = MD_MAJOR_VERSION;
5449 	mddev->minor_version = MD_MINOR_VERSION;
5450 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5451 	mddev->ctime         = get_seconds();
5452 
5453 	mddev->level         = info->level;
5454 	mddev->clevel[0]     = 0;
5455 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5456 	mddev->raid_disks    = info->raid_disks;
5457 	/* don't set md_minor, it is determined by which /dev/md* was
5458 	 * openned
5459 	 */
5460 	if (info->state & (1<<MD_SB_CLEAN))
5461 		mddev->recovery_cp = MaxSector;
5462 	else
5463 		mddev->recovery_cp = 0;
5464 	mddev->persistent    = ! info->not_persistent;
5465 	mddev->external	     = 0;
5466 
5467 	mddev->layout        = info->layout;
5468 	mddev->chunk_sectors = info->chunk_size >> 9;
5469 
5470 	mddev->max_disks     = MD_SB_DISKS;
5471 
5472 	if (mddev->persistent)
5473 		mddev->flags         = 0;
5474 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5475 
5476 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
5477 	mddev->bitmap_info.offset = 0;
5478 
5479 	mddev->reshape_position = MaxSector;
5480 
5481 	/*
5482 	 * Generate a 128 bit UUID
5483 	 */
5484 	get_random_bytes(mddev->uuid, 16);
5485 
5486 	mddev->new_level = mddev->level;
5487 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5488 	mddev->new_layout = mddev->layout;
5489 	mddev->delta_disks = 0;
5490 
5491 	return 0;
5492 }
5493 
5494 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5495 {
5496 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5497 
5498 	if (mddev->external_size)
5499 		return;
5500 
5501 	mddev->array_sectors = array_sectors;
5502 }
5503 EXPORT_SYMBOL(md_set_array_sectors);
5504 
5505 static int update_size(mddev_t *mddev, sector_t num_sectors)
5506 {
5507 	mdk_rdev_t *rdev;
5508 	int rv;
5509 	int fit = (num_sectors == 0);
5510 
5511 	if (mddev->pers->resize == NULL)
5512 		return -EINVAL;
5513 	/* The "num_sectors" is the number of sectors of each device that
5514 	 * is used.  This can only make sense for arrays with redundancy.
5515 	 * linear and raid0 always use whatever space is available. We can only
5516 	 * consider changing this number if no resync or reconstruction is
5517 	 * happening, and if the new size is acceptable. It must fit before the
5518 	 * sb_start or, if that is <data_offset, it must fit before the size
5519 	 * of each device.  If num_sectors is zero, we find the largest size
5520 	 * that fits.
5521 
5522 	 */
5523 	if (mddev->sync_thread)
5524 		return -EBUSY;
5525 	if (mddev->bitmap)
5526 		/* Sorry, cannot grow a bitmap yet, just remove it,
5527 		 * grow, and re-add.
5528 		 */
5529 		return -EBUSY;
5530 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5531 		sector_t avail = rdev->sectors;
5532 
5533 		if (fit && (num_sectors == 0 || num_sectors > avail))
5534 			num_sectors = avail;
5535 		if (avail < num_sectors)
5536 			return -ENOSPC;
5537 	}
5538 	rv = mddev->pers->resize(mddev, num_sectors);
5539 	if (!rv)
5540 		revalidate_disk(mddev->gendisk);
5541 	return rv;
5542 }
5543 
5544 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5545 {
5546 	int rv;
5547 	/* change the number of raid disks */
5548 	if (mddev->pers->check_reshape == NULL)
5549 		return -EINVAL;
5550 	if (raid_disks <= 0 ||
5551 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
5552 		return -EINVAL;
5553 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5554 		return -EBUSY;
5555 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5556 
5557 	rv = mddev->pers->check_reshape(mddev);
5558 	return rv;
5559 }
5560 
5561 
5562 /*
5563  * update_array_info is used to change the configuration of an
5564  * on-line array.
5565  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5566  * fields in the info are checked against the array.
5567  * Any differences that cannot be handled will cause an error.
5568  * Normally, only one change can be managed at a time.
5569  */
5570 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5571 {
5572 	int rv = 0;
5573 	int cnt = 0;
5574 	int state = 0;
5575 
5576 	/* calculate expected state,ignoring low bits */
5577 	if (mddev->bitmap && mddev->bitmap_info.offset)
5578 		state |= (1 << MD_SB_BITMAP_PRESENT);
5579 
5580 	if (mddev->major_version != info->major_version ||
5581 	    mddev->minor_version != info->minor_version ||
5582 /*	    mddev->patch_version != info->patch_version || */
5583 	    mddev->ctime         != info->ctime         ||
5584 	    mddev->level         != info->level         ||
5585 /*	    mddev->layout        != info->layout        || */
5586 	    !mddev->persistent	 != info->not_persistent||
5587 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5588 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5589 	    ((state^info->state) & 0xfffffe00)
5590 		)
5591 		return -EINVAL;
5592 	/* Check there is only one change */
5593 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5594 		cnt++;
5595 	if (mddev->raid_disks != info->raid_disks)
5596 		cnt++;
5597 	if (mddev->layout != info->layout)
5598 		cnt++;
5599 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5600 		cnt++;
5601 	if (cnt == 0)
5602 		return 0;
5603 	if (cnt > 1)
5604 		return -EINVAL;
5605 
5606 	if (mddev->layout != info->layout) {
5607 		/* Change layout
5608 		 * we don't need to do anything at the md level, the
5609 		 * personality will take care of it all.
5610 		 */
5611 		if (mddev->pers->check_reshape == NULL)
5612 			return -EINVAL;
5613 		else {
5614 			mddev->new_layout = info->layout;
5615 			rv = mddev->pers->check_reshape(mddev);
5616 			if (rv)
5617 				mddev->new_layout = mddev->layout;
5618 			return rv;
5619 		}
5620 	}
5621 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5622 		rv = update_size(mddev, (sector_t)info->size * 2);
5623 
5624 	if (mddev->raid_disks    != info->raid_disks)
5625 		rv = update_raid_disks(mddev, info->raid_disks);
5626 
5627 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5628 		if (mddev->pers->quiesce == NULL)
5629 			return -EINVAL;
5630 		if (mddev->recovery || mddev->sync_thread)
5631 			return -EBUSY;
5632 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5633 			/* add the bitmap */
5634 			if (mddev->bitmap)
5635 				return -EEXIST;
5636 			if (mddev->bitmap_info.default_offset == 0)
5637 				return -EINVAL;
5638 			mddev->bitmap_info.offset =
5639 				mddev->bitmap_info.default_offset;
5640 			mddev->pers->quiesce(mddev, 1);
5641 			rv = bitmap_create(mddev);
5642 			if (!rv)
5643 				rv = bitmap_load(mddev);
5644 			if (rv)
5645 				bitmap_destroy(mddev);
5646 			mddev->pers->quiesce(mddev, 0);
5647 		} else {
5648 			/* remove the bitmap */
5649 			if (!mddev->bitmap)
5650 				return -ENOENT;
5651 			if (mddev->bitmap->file)
5652 				return -EINVAL;
5653 			mddev->pers->quiesce(mddev, 1);
5654 			bitmap_destroy(mddev);
5655 			mddev->pers->quiesce(mddev, 0);
5656 			mddev->bitmap_info.offset = 0;
5657 		}
5658 	}
5659 	md_update_sb(mddev, 1);
5660 	return rv;
5661 }
5662 
5663 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5664 {
5665 	mdk_rdev_t *rdev;
5666 
5667 	if (mddev->pers == NULL)
5668 		return -ENODEV;
5669 
5670 	rdev = find_rdev(mddev, dev);
5671 	if (!rdev)
5672 		return -ENODEV;
5673 
5674 	md_error(mddev, rdev);
5675 	return 0;
5676 }
5677 
5678 /*
5679  * We have a problem here : there is no easy way to give a CHS
5680  * virtual geometry. We currently pretend that we have a 2 heads
5681  * 4 sectors (with a BIG number of cylinders...). This drives
5682  * dosfs just mad... ;-)
5683  */
5684 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5685 {
5686 	mddev_t *mddev = bdev->bd_disk->private_data;
5687 
5688 	geo->heads = 2;
5689 	geo->sectors = 4;
5690 	geo->cylinders = mddev->array_sectors / 8;
5691 	return 0;
5692 }
5693 
5694 static int md_ioctl(struct block_device *bdev, fmode_t mode,
5695 			unsigned int cmd, unsigned long arg)
5696 {
5697 	int err = 0;
5698 	void __user *argp = (void __user *)arg;
5699 	mddev_t *mddev = NULL;
5700 	int ro;
5701 
5702 	if (!capable(CAP_SYS_ADMIN))
5703 		return -EACCES;
5704 
5705 	/*
5706 	 * Commands dealing with the RAID driver but not any
5707 	 * particular array:
5708 	 */
5709 	switch (cmd)
5710 	{
5711 		case RAID_VERSION:
5712 			err = get_version(argp);
5713 			goto done;
5714 
5715 		case PRINT_RAID_DEBUG:
5716 			err = 0;
5717 			md_print_devices();
5718 			goto done;
5719 
5720 #ifndef MODULE
5721 		case RAID_AUTORUN:
5722 			err = 0;
5723 			autostart_arrays(arg);
5724 			goto done;
5725 #endif
5726 		default:;
5727 	}
5728 
5729 	/*
5730 	 * Commands creating/starting a new array:
5731 	 */
5732 
5733 	mddev = bdev->bd_disk->private_data;
5734 
5735 	if (!mddev) {
5736 		BUG();
5737 		goto abort;
5738 	}
5739 
5740 	err = mddev_lock(mddev);
5741 	if (err) {
5742 		printk(KERN_INFO
5743 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5744 			err, cmd);
5745 		goto abort;
5746 	}
5747 
5748 	switch (cmd)
5749 	{
5750 		case SET_ARRAY_INFO:
5751 			{
5752 				mdu_array_info_t info;
5753 				if (!arg)
5754 					memset(&info, 0, sizeof(info));
5755 				else if (copy_from_user(&info, argp, sizeof(info))) {
5756 					err = -EFAULT;
5757 					goto abort_unlock;
5758 				}
5759 				if (mddev->pers) {
5760 					err = update_array_info(mddev, &info);
5761 					if (err) {
5762 						printk(KERN_WARNING "md: couldn't update"
5763 						       " array info. %d\n", err);
5764 						goto abort_unlock;
5765 					}
5766 					goto done_unlock;
5767 				}
5768 				if (!list_empty(&mddev->disks)) {
5769 					printk(KERN_WARNING
5770 					       "md: array %s already has disks!\n",
5771 					       mdname(mddev));
5772 					err = -EBUSY;
5773 					goto abort_unlock;
5774 				}
5775 				if (mddev->raid_disks) {
5776 					printk(KERN_WARNING
5777 					       "md: array %s already initialised!\n",
5778 					       mdname(mddev));
5779 					err = -EBUSY;
5780 					goto abort_unlock;
5781 				}
5782 				err = set_array_info(mddev, &info);
5783 				if (err) {
5784 					printk(KERN_WARNING "md: couldn't set"
5785 					       " array info. %d\n", err);
5786 					goto abort_unlock;
5787 				}
5788 			}
5789 			goto done_unlock;
5790 
5791 		default:;
5792 	}
5793 
5794 	/*
5795 	 * Commands querying/configuring an existing array:
5796 	 */
5797 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5798 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5799 	if ((!mddev->raid_disks && !mddev->external)
5800 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5801 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5802 	    && cmd != GET_BITMAP_FILE) {
5803 		err = -ENODEV;
5804 		goto abort_unlock;
5805 	}
5806 
5807 	/*
5808 	 * Commands even a read-only array can execute:
5809 	 */
5810 	switch (cmd)
5811 	{
5812 		case GET_ARRAY_INFO:
5813 			err = get_array_info(mddev, argp);
5814 			goto done_unlock;
5815 
5816 		case GET_BITMAP_FILE:
5817 			err = get_bitmap_file(mddev, argp);
5818 			goto done_unlock;
5819 
5820 		case GET_DISK_INFO:
5821 			err = get_disk_info(mddev, argp);
5822 			goto done_unlock;
5823 
5824 		case RESTART_ARRAY_RW:
5825 			err = restart_array(mddev);
5826 			goto done_unlock;
5827 
5828 		case STOP_ARRAY:
5829 			err = do_md_stop(mddev, 0, 1);
5830 			goto done_unlock;
5831 
5832 		case STOP_ARRAY_RO:
5833 			err = md_set_readonly(mddev, 1);
5834 			goto done_unlock;
5835 
5836 		case BLKROSET:
5837 			if (get_user(ro, (int __user *)(arg))) {
5838 				err = -EFAULT;
5839 				goto done_unlock;
5840 			}
5841 			err = -EINVAL;
5842 
5843 			/* if the bdev is going readonly the value of mddev->ro
5844 			 * does not matter, no writes are coming
5845 			 */
5846 			if (ro)
5847 				goto done_unlock;
5848 
5849 			/* are we are already prepared for writes? */
5850 			if (mddev->ro != 1)
5851 				goto done_unlock;
5852 
5853 			/* transitioning to readauto need only happen for
5854 			 * arrays that call md_write_start
5855 			 */
5856 			if (mddev->pers) {
5857 				err = restart_array(mddev);
5858 				if (err == 0) {
5859 					mddev->ro = 2;
5860 					set_disk_ro(mddev->gendisk, 0);
5861 				}
5862 			}
5863 			goto done_unlock;
5864 	}
5865 
5866 	/*
5867 	 * The remaining ioctls are changing the state of the
5868 	 * superblock, so we do not allow them on read-only arrays.
5869 	 * However non-MD ioctls (e.g. get-size) will still come through
5870 	 * here and hit the 'default' below, so only disallow
5871 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5872 	 */
5873 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5874 		if (mddev->ro == 2) {
5875 			mddev->ro = 0;
5876 			sysfs_notify_dirent_safe(mddev->sysfs_state);
5877 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5878 			md_wakeup_thread(mddev->thread);
5879 		} else {
5880 			err = -EROFS;
5881 			goto abort_unlock;
5882 		}
5883 	}
5884 
5885 	switch (cmd)
5886 	{
5887 		case ADD_NEW_DISK:
5888 		{
5889 			mdu_disk_info_t info;
5890 			if (copy_from_user(&info, argp, sizeof(info)))
5891 				err = -EFAULT;
5892 			else
5893 				err = add_new_disk(mddev, &info);
5894 			goto done_unlock;
5895 		}
5896 
5897 		case HOT_REMOVE_DISK:
5898 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5899 			goto done_unlock;
5900 
5901 		case HOT_ADD_DISK:
5902 			err = hot_add_disk(mddev, new_decode_dev(arg));
5903 			goto done_unlock;
5904 
5905 		case SET_DISK_FAULTY:
5906 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5907 			goto done_unlock;
5908 
5909 		case RUN_ARRAY:
5910 			err = do_md_run(mddev);
5911 			goto done_unlock;
5912 
5913 		case SET_BITMAP_FILE:
5914 			err = set_bitmap_file(mddev, (int)arg);
5915 			goto done_unlock;
5916 
5917 		default:
5918 			err = -EINVAL;
5919 			goto abort_unlock;
5920 	}
5921 
5922 done_unlock:
5923 abort_unlock:
5924 	if (mddev->hold_active == UNTIL_IOCTL &&
5925 	    err != -EINVAL)
5926 		mddev->hold_active = 0;
5927 	mddev_unlock(mddev);
5928 
5929 	return err;
5930 done:
5931 	if (err)
5932 		MD_BUG();
5933 abort:
5934 	return err;
5935 }
5936 #ifdef CONFIG_COMPAT
5937 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
5938 		    unsigned int cmd, unsigned long arg)
5939 {
5940 	switch (cmd) {
5941 	case HOT_REMOVE_DISK:
5942 	case HOT_ADD_DISK:
5943 	case SET_DISK_FAULTY:
5944 	case SET_BITMAP_FILE:
5945 		/* These take in integer arg, do not convert */
5946 		break;
5947 	default:
5948 		arg = (unsigned long)compat_ptr(arg);
5949 		break;
5950 	}
5951 
5952 	return md_ioctl(bdev, mode, cmd, arg);
5953 }
5954 #endif /* CONFIG_COMPAT */
5955 
5956 static int md_open(struct block_device *bdev, fmode_t mode)
5957 {
5958 	/*
5959 	 * Succeed if we can lock the mddev, which confirms that
5960 	 * it isn't being stopped right now.
5961 	 */
5962 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5963 	int err;
5964 
5965 	if (mddev->gendisk != bdev->bd_disk) {
5966 		/* we are racing with mddev_put which is discarding this
5967 		 * bd_disk.
5968 		 */
5969 		mddev_put(mddev);
5970 		/* Wait until bdev->bd_disk is definitely gone */
5971 		flush_workqueue(md_misc_wq);
5972 		/* Then retry the open from the top */
5973 		return -ERESTARTSYS;
5974 	}
5975 	BUG_ON(mddev != bdev->bd_disk->private_data);
5976 
5977 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
5978 		goto out;
5979 
5980 	err = 0;
5981 	atomic_inc(&mddev->openers);
5982 	mutex_unlock(&mddev->open_mutex);
5983 
5984 	check_disk_size_change(mddev->gendisk, bdev);
5985  out:
5986 	return err;
5987 }
5988 
5989 static int md_release(struct gendisk *disk, fmode_t mode)
5990 {
5991  	mddev_t *mddev = disk->private_data;
5992 
5993 	BUG_ON(!mddev);
5994 	atomic_dec(&mddev->openers);
5995 	mddev_put(mddev);
5996 
5997 	return 0;
5998 }
5999 static const struct block_device_operations md_fops =
6000 {
6001 	.owner		= THIS_MODULE,
6002 	.open		= md_open,
6003 	.release	= md_release,
6004 	.ioctl		= md_ioctl,
6005 #ifdef CONFIG_COMPAT
6006 	.compat_ioctl	= md_compat_ioctl,
6007 #endif
6008 	.getgeo		= md_getgeo,
6009 };
6010 
6011 static int md_thread(void * arg)
6012 {
6013 	mdk_thread_t *thread = arg;
6014 
6015 	/*
6016 	 * md_thread is a 'system-thread', it's priority should be very
6017 	 * high. We avoid resource deadlocks individually in each
6018 	 * raid personality. (RAID5 does preallocation) We also use RR and
6019 	 * the very same RT priority as kswapd, thus we will never get
6020 	 * into a priority inversion deadlock.
6021 	 *
6022 	 * we definitely have to have equal or higher priority than
6023 	 * bdflush, otherwise bdflush will deadlock if there are too
6024 	 * many dirty RAID5 blocks.
6025 	 */
6026 
6027 	allow_signal(SIGKILL);
6028 	while (!kthread_should_stop()) {
6029 
6030 		/* We need to wait INTERRUPTIBLE so that
6031 		 * we don't add to the load-average.
6032 		 * That means we need to be sure no signals are
6033 		 * pending
6034 		 */
6035 		if (signal_pending(current))
6036 			flush_signals(current);
6037 
6038 		wait_event_interruptible_timeout
6039 			(thread->wqueue,
6040 			 test_bit(THREAD_WAKEUP, &thread->flags)
6041 			 || kthread_should_stop(),
6042 			 thread->timeout);
6043 
6044 		if (test_and_clear_bit(THREAD_WAKEUP, &thread->flags))
6045 			thread->run(thread->mddev);
6046 	}
6047 
6048 	return 0;
6049 }
6050 
6051 void md_wakeup_thread(mdk_thread_t *thread)
6052 {
6053 	if (thread) {
6054 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
6055 		set_bit(THREAD_WAKEUP, &thread->flags);
6056 		wake_up(&thread->wqueue);
6057 	}
6058 }
6059 
6060 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
6061 				 const char *name)
6062 {
6063 	mdk_thread_t *thread;
6064 
6065 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
6066 	if (!thread)
6067 		return NULL;
6068 
6069 	init_waitqueue_head(&thread->wqueue);
6070 
6071 	thread->run = run;
6072 	thread->mddev = mddev;
6073 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6074 	thread->tsk = kthread_run(md_thread, thread,
6075 				  "%s_%s",
6076 				  mdname(thread->mddev),
6077 				  name ?: mddev->pers->name);
6078 	if (IS_ERR(thread->tsk)) {
6079 		kfree(thread);
6080 		return NULL;
6081 	}
6082 	return thread;
6083 }
6084 
6085 void md_unregister_thread(mdk_thread_t *thread)
6086 {
6087 	if (!thread)
6088 		return;
6089 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6090 
6091 	kthread_stop(thread->tsk);
6092 	kfree(thread);
6093 }
6094 
6095 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
6096 {
6097 	if (!mddev) {
6098 		MD_BUG();
6099 		return;
6100 	}
6101 
6102 	if (!rdev || test_bit(Faulty, &rdev->flags))
6103 		return;
6104 
6105 	if (mddev->external)
6106 		set_bit(Blocked, &rdev->flags);
6107 /*
6108 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
6109 		mdname(mddev),
6110 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
6111 		__builtin_return_address(0),__builtin_return_address(1),
6112 		__builtin_return_address(2),__builtin_return_address(3));
6113 */
6114 	if (!mddev->pers)
6115 		return;
6116 	if (!mddev->pers->error_handler)
6117 		return;
6118 	mddev->pers->error_handler(mddev,rdev);
6119 	if (mddev->degraded)
6120 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6121 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6122 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6123 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6124 	md_wakeup_thread(mddev->thread);
6125 	if (mddev->event_work.func)
6126 		queue_work(md_misc_wq, &mddev->event_work);
6127 	md_new_event_inintr(mddev);
6128 }
6129 
6130 /* seq_file implementation /proc/mdstat */
6131 
6132 static void status_unused(struct seq_file *seq)
6133 {
6134 	int i = 0;
6135 	mdk_rdev_t *rdev;
6136 
6137 	seq_printf(seq, "unused devices: ");
6138 
6139 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6140 		char b[BDEVNAME_SIZE];
6141 		i++;
6142 		seq_printf(seq, "%s ",
6143 			      bdevname(rdev->bdev,b));
6144 	}
6145 	if (!i)
6146 		seq_printf(seq, "<none>");
6147 
6148 	seq_printf(seq, "\n");
6149 }
6150 
6151 
6152 static void status_resync(struct seq_file *seq, mddev_t * mddev)
6153 {
6154 	sector_t max_sectors, resync, res;
6155 	unsigned long dt, db;
6156 	sector_t rt;
6157 	int scale;
6158 	unsigned int per_milli;
6159 
6160 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6161 
6162 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6163 		max_sectors = mddev->resync_max_sectors;
6164 	else
6165 		max_sectors = mddev->dev_sectors;
6166 
6167 	/*
6168 	 * Should not happen.
6169 	 */
6170 	if (!max_sectors) {
6171 		MD_BUG();
6172 		return;
6173 	}
6174 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6175 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6176 	 * u32, as those are the requirements for sector_div.
6177 	 * Thus 'scale' must be at least 10
6178 	 */
6179 	scale = 10;
6180 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6181 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6182 			scale++;
6183 	}
6184 	res = (resync>>scale)*1000;
6185 	sector_div(res, (u32)((max_sectors>>scale)+1));
6186 
6187 	per_milli = res;
6188 	{
6189 		int i, x = per_milli/50, y = 20-x;
6190 		seq_printf(seq, "[");
6191 		for (i = 0; i < x; i++)
6192 			seq_printf(seq, "=");
6193 		seq_printf(seq, ">");
6194 		for (i = 0; i < y; i++)
6195 			seq_printf(seq, ".");
6196 		seq_printf(seq, "] ");
6197 	}
6198 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6199 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6200 		    "reshape" :
6201 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6202 		     "check" :
6203 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6204 		      "resync" : "recovery"))),
6205 		   per_milli/10, per_milli % 10,
6206 		   (unsigned long long) resync/2,
6207 		   (unsigned long long) max_sectors/2);
6208 
6209 	/*
6210 	 * dt: time from mark until now
6211 	 * db: blocks written from mark until now
6212 	 * rt: remaining time
6213 	 *
6214 	 * rt is a sector_t, so could be 32bit or 64bit.
6215 	 * So we divide before multiply in case it is 32bit and close
6216 	 * to the limit.
6217 	 * We scale the divisor (db) by 32 to avoid loosing precision
6218 	 * near the end of resync when the number of remaining sectors
6219 	 * is close to 'db'.
6220 	 * We then divide rt by 32 after multiplying by db to compensate.
6221 	 * The '+1' avoids division by zero if db is very small.
6222 	 */
6223 	dt = ((jiffies - mddev->resync_mark) / HZ);
6224 	if (!dt) dt++;
6225 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6226 		- mddev->resync_mark_cnt;
6227 
6228 	rt = max_sectors - resync;    /* number of remaining sectors */
6229 	sector_div(rt, db/32+1);
6230 	rt *= dt;
6231 	rt >>= 5;
6232 
6233 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6234 		   ((unsigned long)rt % 60)/6);
6235 
6236 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6237 }
6238 
6239 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6240 {
6241 	struct list_head *tmp;
6242 	loff_t l = *pos;
6243 	mddev_t *mddev;
6244 
6245 	if (l >= 0x10000)
6246 		return NULL;
6247 	if (!l--)
6248 		/* header */
6249 		return (void*)1;
6250 
6251 	spin_lock(&all_mddevs_lock);
6252 	list_for_each(tmp,&all_mddevs)
6253 		if (!l--) {
6254 			mddev = list_entry(tmp, mddev_t, all_mddevs);
6255 			mddev_get(mddev);
6256 			spin_unlock(&all_mddevs_lock);
6257 			return mddev;
6258 		}
6259 	spin_unlock(&all_mddevs_lock);
6260 	if (!l--)
6261 		return (void*)2;/* tail */
6262 	return NULL;
6263 }
6264 
6265 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6266 {
6267 	struct list_head *tmp;
6268 	mddev_t *next_mddev, *mddev = v;
6269 
6270 	++*pos;
6271 	if (v == (void*)2)
6272 		return NULL;
6273 
6274 	spin_lock(&all_mddevs_lock);
6275 	if (v == (void*)1)
6276 		tmp = all_mddevs.next;
6277 	else
6278 		tmp = mddev->all_mddevs.next;
6279 	if (tmp != &all_mddevs)
6280 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
6281 	else {
6282 		next_mddev = (void*)2;
6283 		*pos = 0x10000;
6284 	}
6285 	spin_unlock(&all_mddevs_lock);
6286 
6287 	if (v != (void*)1)
6288 		mddev_put(mddev);
6289 	return next_mddev;
6290 
6291 }
6292 
6293 static void md_seq_stop(struct seq_file *seq, void *v)
6294 {
6295 	mddev_t *mddev = v;
6296 
6297 	if (mddev && v != (void*)1 && v != (void*)2)
6298 		mddev_put(mddev);
6299 }
6300 
6301 struct mdstat_info {
6302 	int event;
6303 };
6304 
6305 static int md_seq_show(struct seq_file *seq, void *v)
6306 {
6307 	mddev_t *mddev = v;
6308 	sector_t sectors;
6309 	mdk_rdev_t *rdev;
6310 	struct mdstat_info *mi = seq->private;
6311 	struct bitmap *bitmap;
6312 
6313 	if (v == (void*)1) {
6314 		struct mdk_personality *pers;
6315 		seq_printf(seq, "Personalities : ");
6316 		spin_lock(&pers_lock);
6317 		list_for_each_entry(pers, &pers_list, list)
6318 			seq_printf(seq, "[%s] ", pers->name);
6319 
6320 		spin_unlock(&pers_lock);
6321 		seq_printf(seq, "\n");
6322 		mi->event = atomic_read(&md_event_count);
6323 		return 0;
6324 	}
6325 	if (v == (void*)2) {
6326 		status_unused(seq);
6327 		return 0;
6328 	}
6329 
6330 	if (mddev_lock(mddev) < 0)
6331 		return -EINTR;
6332 
6333 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6334 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6335 						mddev->pers ? "" : "in");
6336 		if (mddev->pers) {
6337 			if (mddev->ro==1)
6338 				seq_printf(seq, " (read-only)");
6339 			if (mddev->ro==2)
6340 				seq_printf(seq, " (auto-read-only)");
6341 			seq_printf(seq, " %s", mddev->pers->name);
6342 		}
6343 
6344 		sectors = 0;
6345 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6346 			char b[BDEVNAME_SIZE];
6347 			seq_printf(seq, " %s[%d]",
6348 				bdevname(rdev->bdev,b), rdev->desc_nr);
6349 			if (test_bit(WriteMostly, &rdev->flags))
6350 				seq_printf(seq, "(W)");
6351 			if (test_bit(Faulty, &rdev->flags)) {
6352 				seq_printf(seq, "(F)");
6353 				continue;
6354 			} else if (rdev->raid_disk < 0)
6355 				seq_printf(seq, "(S)"); /* spare */
6356 			sectors += rdev->sectors;
6357 		}
6358 
6359 		if (!list_empty(&mddev->disks)) {
6360 			if (mddev->pers)
6361 				seq_printf(seq, "\n      %llu blocks",
6362 					   (unsigned long long)
6363 					   mddev->array_sectors / 2);
6364 			else
6365 				seq_printf(seq, "\n      %llu blocks",
6366 					   (unsigned long long)sectors / 2);
6367 		}
6368 		if (mddev->persistent) {
6369 			if (mddev->major_version != 0 ||
6370 			    mddev->minor_version != 90) {
6371 				seq_printf(seq," super %d.%d",
6372 					   mddev->major_version,
6373 					   mddev->minor_version);
6374 			}
6375 		} else if (mddev->external)
6376 			seq_printf(seq, " super external:%s",
6377 				   mddev->metadata_type);
6378 		else
6379 			seq_printf(seq, " super non-persistent");
6380 
6381 		if (mddev->pers) {
6382 			mddev->pers->status(seq, mddev);
6383 	 		seq_printf(seq, "\n      ");
6384 			if (mddev->pers->sync_request) {
6385 				if (mddev->curr_resync > 2) {
6386 					status_resync(seq, mddev);
6387 					seq_printf(seq, "\n      ");
6388 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
6389 					seq_printf(seq, "\tresync=DELAYED\n      ");
6390 				else if (mddev->recovery_cp < MaxSector)
6391 					seq_printf(seq, "\tresync=PENDING\n      ");
6392 			}
6393 		} else
6394 			seq_printf(seq, "\n       ");
6395 
6396 		if ((bitmap = mddev->bitmap)) {
6397 			unsigned long chunk_kb;
6398 			unsigned long flags;
6399 			spin_lock_irqsave(&bitmap->lock, flags);
6400 			chunk_kb = mddev->bitmap_info.chunksize >> 10;
6401 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
6402 				"%lu%s chunk",
6403 				bitmap->pages - bitmap->missing_pages,
6404 				bitmap->pages,
6405 				(bitmap->pages - bitmap->missing_pages)
6406 					<< (PAGE_SHIFT - 10),
6407 				chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
6408 				chunk_kb ? "KB" : "B");
6409 			if (bitmap->file) {
6410 				seq_printf(seq, ", file: ");
6411 				seq_path(seq, &bitmap->file->f_path, " \t\n");
6412 			}
6413 
6414 			seq_printf(seq, "\n");
6415 			spin_unlock_irqrestore(&bitmap->lock, flags);
6416 		}
6417 
6418 		seq_printf(seq, "\n");
6419 	}
6420 	mddev_unlock(mddev);
6421 
6422 	return 0;
6423 }
6424 
6425 static const struct seq_operations md_seq_ops = {
6426 	.start  = md_seq_start,
6427 	.next   = md_seq_next,
6428 	.stop   = md_seq_stop,
6429 	.show   = md_seq_show,
6430 };
6431 
6432 static int md_seq_open(struct inode *inode, struct file *file)
6433 {
6434 	int error;
6435 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
6436 	if (mi == NULL)
6437 		return -ENOMEM;
6438 
6439 	error = seq_open(file, &md_seq_ops);
6440 	if (error)
6441 		kfree(mi);
6442 	else {
6443 		struct seq_file *p = file->private_data;
6444 		p->private = mi;
6445 		mi->event = atomic_read(&md_event_count);
6446 	}
6447 	return error;
6448 }
6449 
6450 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6451 {
6452 	struct seq_file *m = filp->private_data;
6453 	struct mdstat_info *mi = m->private;
6454 	int mask;
6455 
6456 	poll_wait(filp, &md_event_waiters, wait);
6457 
6458 	/* always allow read */
6459 	mask = POLLIN | POLLRDNORM;
6460 
6461 	if (mi->event != atomic_read(&md_event_count))
6462 		mask |= POLLERR | POLLPRI;
6463 	return mask;
6464 }
6465 
6466 static const struct file_operations md_seq_fops = {
6467 	.owner		= THIS_MODULE,
6468 	.open           = md_seq_open,
6469 	.read           = seq_read,
6470 	.llseek         = seq_lseek,
6471 	.release	= seq_release_private,
6472 	.poll		= mdstat_poll,
6473 };
6474 
6475 int register_md_personality(struct mdk_personality *p)
6476 {
6477 	spin_lock(&pers_lock);
6478 	list_add_tail(&p->list, &pers_list);
6479 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6480 	spin_unlock(&pers_lock);
6481 	return 0;
6482 }
6483 
6484 int unregister_md_personality(struct mdk_personality *p)
6485 {
6486 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6487 	spin_lock(&pers_lock);
6488 	list_del_init(&p->list);
6489 	spin_unlock(&pers_lock);
6490 	return 0;
6491 }
6492 
6493 static int is_mddev_idle(mddev_t *mddev, int init)
6494 {
6495 	mdk_rdev_t * rdev;
6496 	int idle;
6497 	int curr_events;
6498 
6499 	idle = 1;
6500 	rcu_read_lock();
6501 	rdev_for_each_rcu(rdev, mddev) {
6502 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6503 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6504 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6505 			      atomic_read(&disk->sync_io);
6506 		/* sync IO will cause sync_io to increase before the disk_stats
6507 		 * as sync_io is counted when a request starts, and
6508 		 * disk_stats is counted when it completes.
6509 		 * So resync activity will cause curr_events to be smaller than
6510 		 * when there was no such activity.
6511 		 * non-sync IO will cause disk_stat to increase without
6512 		 * increasing sync_io so curr_events will (eventually)
6513 		 * be larger than it was before.  Once it becomes
6514 		 * substantially larger, the test below will cause
6515 		 * the array to appear non-idle, and resync will slow
6516 		 * down.
6517 		 * If there is a lot of outstanding resync activity when
6518 		 * we set last_event to curr_events, then all that activity
6519 		 * completing might cause the array to appear non-idle
6520 		 * and resync will be slowed down even though there might
6521 		 * not have been non-resync activity.  This will only
6522 		 * happen once though.  'last_events' will soon reflect
6523 		 * the state where there is little or no outstanding
6524 		 * resync requests, and further resync activity will
6525 		 * always make curr_events less than last_events.
6526 		 *
6527 		 */
6528 		if (init || curr_events - rdev->last_events > 64) {
6529 			rdev->last_events = curr_events;
6530 			idle = 0;
6531 		}
6532 	}
6533 	rcu_read_unlock();
6534 	return idle;
6535 }
6536 
6537 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6538 {
6539 	/* another "blocks" (512byte) blocks have been synced */
6540 	atomic_sub(blocks, &mddev->recovery_active);
6541 	wake_up(&mddev->recovery_wait);
6542 	if (!ok) {
6543 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6544 		md_wakeup_thread(mddev->thread);
6545 		// stop recovery, signal do_sync ....
6546 	}
6547 }
6548 
6549 
6550 /* md_write_start(mddev, bi)
6551  * If we need to update some array metadata (e.g. 'active' flag
6552  * in superblock) before writing, schedule a superblock update
6553  * and wait for it to complete.
6554  */
6555 void md_write_start(mddev_t *mddev, struct bio *bi)
6556 {
6557 	int did_change = 0;
6558 	if (bio_data_dir(bi) != WRITE)
6559 		return;
6560 
6561 	BUG_ON(mddev->ro == 1);
6562 	if (mddev->ro == 2) {
6563 		/* need to switch to read/write */
6564 		mddev->ro = 0;
6565 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6566 		md_wakeup_thread(mddev->thread);
6567 		md_wakeup_thread(mddev->sync_thread);
6568 		did_change = 1;
6569 	}
6570 	atomic_inc(&mddev->writes_pending);
6571 	if (mddev->safemode == 1)
6572 		mddev->safemode = 0;
6573 	if (mddev->in_sync) {
6574 		spin_lock_irq(&mddev->write_lock);
6575 		if (mddev->in_sync) {
6576 			mddev->in_sync = 0;
6577 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6578 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
6579 			md_wakeup_thread(mddev->thread);
6580 			did_change = 1;
6581 		}
6582 		spin_unlock_irq(&mddev->write_lock);
6583 	}
6584 	if (did_change)
6585 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6586 	wait_event(mddev->sb_wait,
6587 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6588 }
6589 
6590 void md_write_end(mddev_t *mddev)
6591 {
6592 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6593 		if (mddev->safemode == 2)
6594 			md_wakeup_thread(mddev->thread);
6595 		else if (mddev->safemode_delay)
6596 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6597 	}
6598 }
6599 
6600 /* md_allow_write(mddev)
6601  * Calling this ensures that the array is marked 'active' so that writes
6602  * may proceed without blocking.  It is important to call this before
6603  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6604  * Must be called with mddev_lock held.
6605  *
6606  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6607  * is dropped, so return -EAGAIN after notifying userspace.
6608  */
6609 int md_allow_write(mddev_t *mddev)
6610 {
6611 	if (!mddev->pers)
6612 		return 0;
6613 	if (mddev->ro)
6614 		return 0;
6615 	if (!mddev->pers->sync_request)
6616 		return 0;
6617 
6618 	spin_lock_irq(&mddev->write_lock);
6619 	if (mddev->in_sync) {
6620 		mddev->in_sync = 0;
6621 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6622 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
6623 		if (mddev->safemode_delay &&
6624 		    mddev->safemode == 0)
6625 			mddev->safemode = 1;
6626 		spin_unlock_irq(&mddev->write_lock);
6627 		md_update_sb(mddev, 0);
6628 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6629 	} else
6630 		spin_unlock_irq(&mddev->write_lock);
6631 
6632 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
6633 		return -EAGAIN;
6634 	else
6635 		return 0;
6636 }
6637 EXPORT_SYMBOL_GPL(md_allow_write);
6638 
6639 void md_unplug(mddev_t *mddev)
6640 {
6641 	if (mddev->queue)
6642 		blk_unplug(mddev->queue);
6643 	if (mddev->plug)
6644 		mddev->plug->unplug_fn(mddev->plug);
6645 }
6646 
6647 #define SYNC_MARKS	10
6648 #define	SYNC_MARK_STEP	(3*HZ)
6649 void md_do_sync(mddev_t *mddev)
6650 {
6651 	mddev_t *mddev2;
6652 	unsigned int currspeed = 0,
6653 		 window;
6654 	sector_t max_sectors,j, io_sectors;
6655 	unsigned long mark[SYNC_MARKS];
6656 	sector_t mark_cnt[SYNC_MARKS];
6657 	int last_mark,m;
6658 	struct list_head *tmp;
6659 	sector_t last_check;
6660 	int skipped = 0;
6661 	mdk_rdev_t *rdev;
6662 	char *desc;
6663 
6664 	/* just incase thread restarts... */
6665 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6666 		return;
6667 	if (mddev->ro) /* never try to sync a read-only array */
6668 		return;
6669 
6670 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6671 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6672 			desc = "data-check";
6673 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6674 			desc = "requested-resync";
6675 		else
6676 			desc = "resync";
6677 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6678 		desc = "reshape";
6679 	else
6680 		desc = "recovery";
6681 
6682 	/* we overload curr_resync somewhat here.
6683 	 * 0 == not engaged in resync at all
6684 	 * 2 == checking that there is no conflict with another sync
6685 	 * 1 == like 2, but have yielded to allow conflicting resync to
6686 	 *		commense
6687 	 * other == active in resync - this many blocks
6688 	 *
6689 	 * Before starting a resync we must have set curr_resync to
6690 	 * 2, and then checked that every "conflicting" array has curr_resync
6691 	 * less than ours.  When we find one that is the same or higher
6692 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6693 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6694 	 * This will mean we have to start checking from the beginning again.
6695 	 *
6696 	 */
6697 
6698 	do {
6699 		mddev->curr_resync = 2;
6700 
6701 	try_again:
6702 		if (kthread_should_stop())
6703 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6704 
6705 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6706 			goto skip;
6707 		for_each_mddev(mddev2, tmp) {
6708 			if (mddev2 == mddev)
6709 				continue;
6710 			if (!mddev->parallel_resync
6711 			&&  mddev2->curr_resync
6712 			&&  match_mddev_units(mddev, mddev2)) {
6713 				DEFINE_WAIT(wq);
6714 				if (mddev < mddev2 && mddev->curr_resync == 2) {
6715 					/* arbitrarily yield */
6716 					mddev->curr_resync = 1;
6717 					wake_up(&resync_wait);
6718 				}
6719 				if (mddev > mddev2 && mddev->curr_resync == 1)
6720 					/* no need to wait here, we can wait the next
6721 					 * time 'round when curr_resync == 2
6722 					 */
6723 					continue;
6724 				/* We need to wait 'interruptible' so as not to
6725 				 * contribute to the load average, and not to
6726 				 * be caught by 'softlockup'
6727 				 */
6728 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
6729 				if (!kthread_should_stop() &&
6730 				    mddev2->curr_resync >= mddev->curr_resync) {
6731 					printk(KERN_INFO "md: delaying %s of %s"
6732 					       " until %s has finished (they"
6733 					       " share one or more physical units)\n",
6734 					       desc, mdname(mddev), mdname(mddev2));
6735 					mddev_put(mddev2);
6736 					if (signal_pending(current))
6737 						flush_signals(current);
6738 					schedule();
6739 					finish_wait(&resync_wait, &wq);
6740 					goto try_again;
6741 				}
6742 				finish_wait(&resync_wait, &wq);
6743 			}
6744 		}
6745 	} while (mddev->curr_resync < 2);
6746 
6747 	j = 0;
6748 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6749 		/* resync follows the size requested by the personality,
6750 		 * which defaults to physical size, but can be virtual size
6751 		 */
6752 		max_sectors = mddev->resync_max_sectors;
6753 		mddev->resync_mismatches = 0;
6754 		/* we don't use the checkpoint if there's a bitmap */
6755 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6756 			j = mddev->resync_min;
6757 		else if (!mddev->bitmap)
6758 			j = mddev->recovery_cp;
6759 
6760 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6761 		max_sectors = mddev->dev_sectors;
6762 	else {
6763 		/* recovery follows the physical size of devices */
6764 		max_sectors = mddev->dev_sectors;
6765 		j = MaxSector;
6766 		rcu_read_lock();
6767 		list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
6768 			if (rdev->raid_disk >= 0 &&
6769 			    !test_bit(Faulty, &rdev->flags) &&
6770 			    !test_bit(In_sync, &rdev->flags) &&
6771 			    rdev->recovery_offset < j)
6772 				j = rdev->recovery_offset;
6773 		rcu_read_unlock();
6774 	}
6775 
6776 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
6777 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
6778 		" %d KB/sec/disk.\n", speed_min(mddev));
6779 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6780 	       "(but not more than %d KB/sec) for %s.\n",
6781 	       speed_max(mddev), desc);
6782 
6783 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
6784 
6785 	io_sectors = 0;
6786 	for (m = 0; m < SYNC_MARKS; m++) {
6787 		mark[m] = jiffies;
6788 		mark_cnt[m] = io_sectors;
6789 	}
6790 	last_mark = 0;
6791 	mddev->resync_mark = mark[last_mark];
6792 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6793 
6794 	/*
6795 	 * Tune reconstruction:
6796 	 */
6797 	window = 32*(PAGE_SIZE/512);
6798 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6799 		window/2,(unsigned long long) max_sectors/2);
6800 
6801 	atomic_set(&mddev->recovery_active, 0);
6802 	last_check = 0;
6803 
6804 	if (j>2) {
6805 		printk(KERN_INFO
6806 		       "md: resuming %s of %s from checkpoint.\n",
6807 		       desc, mdname(mddev));
6808 		mddev->curr_resync = j;
6809 	}
6810 	mddev->curr_resync_completed = mddev->curr_resync;
6811 
6812 	while (j < max_sectors) {
6813 		sector_t sectors;
6814 
6815 		skipped = 0;
6816 
6817 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6818 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
6819 		      (mddev->curr_resync - mddev->curr_resync_completed)
6820 		      > (max_sectors >> 4)) ||
6821 		     (j - mddev->curr_resync_completed)*2
6822 		     >= mddev->resync_max - mddev->curr_resync_completed
6823 			    )) {
6824 			/* time to update curr_resync_completed */
6825 			md_unplug(mddev);
6826 			wait_event(mddev->recovery_wait,
6827 				   atomic_read(&mddev->recovery_active) == 0);
6828 			mddev->curr_resync_completed =
6829 				mddev->curr_resync;
6830 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6831 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6832 		}
6833 
6834 		while (j >= mddev->resync_max && !kthread_should_stop()) {
6835 			/* As this condition is controlled by user-space,
6836 			 * we can block indefinitely, so use '_interruptible'
6837 			 * to avoid triggering warnings.
6838 			 */
6839 			flush_signals(current); /* just in case */
6840 			wait_event_interruptible(mddev->recovery_wait,
6841 						 mddev->resync_max > j
6842 						 || kthread_should_stop());
6843 		}
6844 
6845 		if (kthread_should_stop())
6846 			goto interrupted;
6847 
6848 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6849 						  currspeed < speed_min(mddev));
6850 		if (sectors == 0) {
6851 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6852 			goto out;
6853 		}
6854 
6855 		if (!skipped) { /* actual IO requested */
6856 			io_sectors += sectors;
6857 			atomic_add(sectors, &mddev->recovery_active);
6858 		}
6859 
6860 		j += sectors;
6861 		if (j>1) mddev->curr_resync = j;
6862 		mddev->curr_mark_cnt = io_sectors;
6863 		if (last_check == 0)
6864 			/* this is the earliers that rebuilt will be
6865 			 * visible in /proc/mdstat
6866 			 */
6867 			md_new_event(mddev);
6868 
6869 		if (last_check + window > io_sectors || j == max_sectors)
6870 			continue;
6871 
6872 		last_check = io_sectors;
6873 
6874 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6875 			break;
6876 
6877 	repeat:
6878 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6879 			/* step marks */
6880 			int next = (last_mark+1) % SYNC_MARKS;
6881 
6882 			mddev->resync_mark = mark[next];
6883 			mddev->resync_mark_cnt = mark_cnt[next];
6884 			mark[next] = jiffies;
6885 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6886 			last_mark = next;
6887 		}
6888 
6889 
6890 		if (kthread_should_stop())
6891 			goto interrupted;
6892 
6893 
6894 		/*
6895 		 * this loop exits only if either when we are slower than
6896 		 * the 'hard' speed limit, or the system was IO-idle for
6897 		 * a jiffy.
6898 		 * the system might be non-idle CPU-wise, but we only care
6899 		 * about not overloading the IO subsystem. (things like an
6900 		 * e2fsck being done on the RAID array should execute fast)
6901 		 */
6902 		md_unplug(mddev);
6903 		cond_resched();
6904 
6905 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6906 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6907 
6908 		if (currspeed > speed_min(mddev)) {
6909 			if ((currspeed > speed_max(mddev)) ||
6910 					!is_mddev_idle(mddev, 0)) {
6911 				msleep(500);
6912 				goto repeat;
6913 			}
6914 		}
6915 	}
6916 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6917 	/*
6918 	 * this also signals 'finished resyncing' to md_stop
6919 	 */
6920  out:
6921 	md_unplug(mddev);
6922 
6923 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6924 
6925 	/* tell personality that we are finished */
6926 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6927 
6928 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6929 	    mddev->curr_resync > 2) {
6930 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6931 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6932 				if (mddev->curr_resync >= mddev->recovery_cp) {
6933 					printk(KERN_INFO
6934 					       "md: checkpointing %s of %s.\n",
6935 					       desc, mdname(mddev));
6936 					mddev->recovery_cp = mddev->curr_resync;
6937 				}
6938 			} else
6939 				mddev->recovery_cp = MaxSector;
6940 		} else {
6941 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6942 				mddev->curr_resync = MaxSector;
6943 			rcu_read_lock();
6944 			list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
6945 				if (rdev->raid_disk >= 0 &&
6946 				    mddev->delta_disks >= 0 &&
6947 				    !test_bit(Faulty, &rdev->flags) &&
6948 				    !test_bit(In_sync, &rdev->flags) &&
6949 				    rdev->recovery_offset < mddev->curr_resync)
6950 					rdev->recovery_offset = mddev->curr_resync;
6951 			rcu_read_unlock();
6952 		}
6953 	}
6954 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6955 
6956  skip:
6957 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6958 		/* We completed so min/max setting can be forgotten if used. */
6959 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6960 			mddev->resync_min = 0;
6961 		mddev->resync_max = MaxSector;
6962 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6963 		mddev->resync_min = mddev->curr_resync_completed;
6964 	mddev->curr_resync = 0;
6965 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6966 		mddev->curr_resync_completed = 0;
6967 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6968 	wake_up(&resync_wait);
6969 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6970 	md_wakeup_thread(mddev->thread);
6971 	return;
6972 
6973  interrupted:
6974 	/*
6975 	 * got a signal, exit.
6976 	 */
6977 	printk(KERN_INFO
6978 	       "md: md_do_sync() got signal ... exiting\n");
6979 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6980 	goto out;
6981 
6982 }
6983 EXPORT_SYMBOL_GPL(md_do_sync);
6984 
6985 
6986 static int remove_and_add_spares(mddev_t *mddev)
6987 {
6988 	mdk_rdev_t *rdev;
6989 	int spares = 0;
6990 
6991 	mddev->curr_resync_completed = 0;
6992 
6993 	list_for_each_entry(rdev, &mddev->disks, same_set)
6994 		if (rdev->raid_disk >= 0 &&
6995 		    !test_bit(Blocked, &rdev->flags) &&
6996 		    (test_bit(Faulty, &rdev->flags) ||
6997 		     ! test_bit(In_sync, &rdev->flags)) &&
6998 		    atomic_read(&rdev->nr_pending)==0) {
6999 			if (mddev->pers->hot_remove_disk(
7000 				    mddev, rdev->raid_disk)==0) {
7001 				char nm[20];
7002 				sprintf(nm,"rd%d", rdev->raid_disk);
7003 				sysfs_remove_link(&mddev->kobj, nm);
7004 				rdev->raid_disk = -1;
7005 			}
7006 		}
7007 
7008 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
7009 		list_for_each_entry(rdev, &mddev->disks, same_set) {
7010 			if (rdev->raid_disk >= 0 &&
7011 			    !test_bit(In_sync, &rdev->flags) &&
7012 			    !test_bit(Blocked, &rdev->flags))
7013 				spares++;
7014 			if (rdev->raid_disk < 0
7015 			    && !test_bit(Faulty, &rdev->flags)) {
7016 				rdev->recovery_offset = 0;
7017 				if (mddev->pers->
7018 				    hot_add_disk(mddev, rdev) == 0) {
7019 					char nm[20];
7020 					sprintf(nm, "rd%d", rdev->raid_disk);
7021 					if (sysfs_create_link(&mddev->kobj,
7022 							      &rdev->kobj, nm))
7023 						/* failure here is OK */;
7024 					spares++;
7025 					md_new_event(mddev);
7026 					set_bit(MD_CHANGE_DEVS, &mddev->flags);
7027 				} else
7028 					break;
7029 			}
7030 		}
7031 	}
7032 	return spares;
7033 }
7034 /*
7035  * This routine is regularly called by all per-raid-array threads to
7036  * deal with generic issues like resync and super-block update.
7037  * Raid personalities that don't have a thread (linear/raid0) do not
7038  * need this as they never do any recovery or update the superblock.
7039  *
7040  * It does not do any resync itself, but rather "forks" off other threads
7041  * to do that as needed.
7042  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7043  * "->recovery" and create a thread at ->sync_thread.
7044  * When the thread finishes it sets MD_RECOVERY_DONE
7045  * and wakeups up this thread which will reap the thread and finish up.
7046  * This thread also removes any faulty devices (with nr_pending == 0).
7047  *
7048  * The overall approach is:
7049  *  1/ if the superblock needs updating, update it.
7050  *  2/ If a recovery thread is running, don't do anything else.
7051  *  3/ If recovery has finished, clean up, possibly marking spares active.
7052  *  4/ If there are any faulty devices, remove them.
7053  *  5/ If array is degraded, try to add spares devices
7054  *  6/ If array has spares or is not in-sync, start a resync thread.
7055  */
7056 void md_check_recovery(mddev_t *mddev)
7057 {
7058 	mdk_rdev_t *rdev;
7059 
7060 
7061 	if (mddev->bitmap)
7062 		bitmap_daemon_work(mddev);
7063 
7064 	if (mddev->ro)
7065 		return;
7066 
7067 	if (signal_pending(current)) {
7068 		if (mddev->pers->sync_request && !mddev->external) {
7069 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7070 			       mdname(mddev));
7071 			mddev->safemode = 2;
7072 		}
7073 		flush_signals(current);
7074 	}
7075 
7076 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7077 		return;
7078 	if ( ! (
7079 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7080 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7081 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7082 		(mddev->external == 0 && mddev->safemode == 1) ||
7083 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7084 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7085 		))
7086 		return;
7087 
7088 	if (mddev_trylock(mddev)) {
7089 		int spares = 0;
7090 
7091 		if (mddev->ro) {
7092 			/* Only thing we do on a ro array is remove
7093 			 * failed devices.
7094 			 */
7095 			remove_and_add_spares(mddev);
7096 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7097 			goto unlock;
7098 		}
7099 
7100 		if (!mddev->external) {
7101 			int did_change = 0;
7102 			spin_lock_irq(&mddev->write_lock);
7103 			if (mddev->safemode &&
7104 			    !atomic_read(&mddev->writes_pending) &&
7105 			    !mddev->in_sync &&
7106 			    mddev->recovery_cp == MaxSector) {
7107 				mddev->in_sync = 1;
7108 				did_change = 1;
7109 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7110 			}
7111 			if (mddev->safemode == 1)
7112 				mddev->safemode = 0;
7113 			spin_unlock_irq(&mddev->write_lock);
7114 			if (did_change)
7115 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7116 		}
7117 
7118 		if (mddev->flags)
7119 			md_update_sb(mddev, 0);
7120 
7121 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7122 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7123 			/* resync/recovery still happening */
7124 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7125 			goto unlock;
7126 		}
7127 		if (mddev->sync_thread) {
7128 			/* resync has finished, collect result */
7129 			md_unregister_thread(mddev->sync_thread);
7130 			mddev->sync_thread = NULL;
7131 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7132 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7133 				/* success...*/
7134 				/* activate any spares */
7135 				if (mddev->pers->spare_active(mddev))
7136 					sysfs_notify(&mddev->kobj, NULL,
7137 						     "degraded");
7138 			}
7139 			if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7140 			    mddev->pers->finish_reshape)
7141 				mddev->pers->finish_reshape(mddev);
7142 			md_update_sb(mddev, 1);
7143 
7144 			/* if array is no-longer degraded, then any saved_raid_disk
7145 			 * information must be scrapped
7146 			 */
7147 			if (!mddev->degraded)
7148 				list_for_each_entry(rdev, &mddev->disks, same_set)
7149 					rdev->saved_raid_disk = -1;
7150 
7151 			mddev->recovery = 0;
7152 			/* flag recovery needed just to double check */
7153 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7154 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7155 			md_new_event(mddev);
7156 			goto unlock;
7157 		}
7158 		/* Set RUNNING before clearing NEEDED to avoid
7159 		 * any transients in the value of "sync_action".
7160 		 */
7161 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7162 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7163 		/* Clear some bits that don't mean anything, but
7164 		 * might be left set
7165 		 */
7166 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7167 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7168 
7169 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7170 			goto unlock;
7171 		/* no recovery is running.
7172 		 * remove any failed drives, then
7173 		 * add spares if possible.
7174 		 * Spare are also removed and re-added, to allow
7175 		 * the personality to fail the re-add.
7176 		 */
7177 
7178 		if (mddev->reshape_position != MaxSector) {
7179 			if (mddev->pers->check_reshape == NULL ||
7180 			    mddev->pers->check_reshape(mddev) != 0)
7181 				/* Cannot proceed */
7182 				goto unlock;
7183 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7184 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7185 		} else if ((spares = remove_and_add_spares(mddev))) {
7186 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7187 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7188 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7189 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7190 		} else if (mddev->recovery_cp < MaxSector) {
7191 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7192 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7193 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7194 			/* nothing to be done ... */
7195 			goto unlock;
7196 
7197 		if (mddev->pers->sync_request) {
7198 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
7199 				/* We are adding a device or devices to an array
7200 				 * which has the bitmap stored on all devices.
7201 				 * So make sure all bitmap pages get written
7202 				 */
7203 				bitmap_write_all(mddev->bitmap);
7204 			}
7205 			mddev->sync_thread = md_register_thread(md_do_sync,
7206 								mddev,
7207 								"resync");
7208 			if (!mddev->sync_thread) {
7209 				printk(KERN_ERR "%s: could not start resync"
7210 					" thread...\n",
7211 					mdname(mddev));
7212 				/* leave the spares where they are, it shouldn't hurt */
7213 				mddev->recovery = 0;
7214 			} else
7215 				md_wakeup_thread(mddev->sync_thread);
7216 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7217 			md_new_event(mddev);
7218 		}
7219 	unlock:
7220 		if (!mddev->sync_thread) {
7221 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7222 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7223 					       &mddev->recovery))
7224 				if (mddev->sysfs_action)
7225 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7226 		}
7227 		mddev_unlock(mddev);
7228 	}
7229 }
7230 
7231 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
7232 {
7233 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7234 	wait_event_timeout(rdev->blocked_wait,
7235 			   !test_bit(Blocked, &rdev->flags),
7236 			   msecs_to_jiffies(5000));
7237 	rdev_dec_pending(rdev, mddev);
7238 }
7239 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7240 
7241 static int md_notify_reboot(struct notifier_block *this,
7242 			    unsigned long code, void *x)
7243 {
7244 	struct list_head *tmp;
7245 	mddev_t *mddev;
7246 
7247 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
7248 
7249 		printk(KERN_INFO "md: stopping all md devices.\n");
7250 
7251 		for_each_mddev(mddev, tmp)
7252 			if (mddev_trylock(mddev)) {
7253 				/* Force a switch to readonly even array
7254 				 * appears to still be in use.  Hence
7255 				 * the '100'.
7256 				 */
7257 				md_set_readonly(mddev, 100);
7258 				mddev_unlock(mddev);
7259 			}
7260 		/*
7261 		 * certain more exotic SCSI devices are known to be
7262 		 * volatile wrt too early system reboots. While the
7263 		 * right place to handle this issue is the given
7264 		 * driver, we do want to have a safe RAID driver ...
7265 		 */
7266 		mdelay(1000*1);
7267 	}
7268 	return NOTIFY_DONE;
7269 }
7270 
7271 static struct notifier_block md_notifier = {
7272 	.notifier_call	= md_notify_reboot,
7273 	.next		= NULL,
7274 	.priority	= INT_MAX, /* before any real devices */
7275 };
7276 
7277 static void md_geninit(void)
7278 {
7279 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
7280 
7281 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
7282 }
7283 
7284 static int __init md_init(void)
7285 {
7286 	int ret = -ENOMEM;
7287 
7288 	md_wq = alloc_workqueue("md", WQ_RESCUER, 0);
7289 	if (!md_wq)
7290 		goto err_wq;
7291 
7292 	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
7293 	if (!md_misc_wq)
7294 		goto err_misc_wq;
7295 
7296 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
7297 		goto err_md;
7298 
7299 	if ((ret = register_blkdev(0, "mdp")) < 0)
7300 		goto err_mdp;
7301 	mdp_major = ret;
7302 
7303 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
7304 			    md_probe, NULL, NULL);
7305 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
7306 			    md_probe, NULL, NULL);
7307 
7308 	register_reboot_notifier(&md_notifier);
7309 	raid_table_header = register_sysctl_table(raid_root_table);
7310 
7311 	md_geninit();
7312 	return 0;
7313 
7314 err_mdp:
7315 	unregister_blkdev(MD_MAJOR, "md");
7316 err_md:
7317 	destroy_workqueue(md_misc_wq);
7318 err_misc_wq:
7319 	destroy_workqueue(md_wq);
7320 err_wq:
7321 	return ret;
7322 }
7323 
7324 #ifndef MODULE
7325 
7326 /*
7327  * Searches all registered partitions for autorun RAID arrays
7328  * at boot time.
7329  */
7330 
7331 static LIST_HEAD(all_detected_devices);
7332 struct detected_devices_node {
7333 	struct list_head list;
7334 	dev_t dev;
7335 };
7336 
7337 void md_autodetect_dev(dev_t dev)
7338 {
7339 	struct detected_devices_node *node_detected_dev;
7340 
7341 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
7342 	if (node_detected_dev) {
7343 		node_detected_dev->dev = dev;
7344 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
7345 	} else {
7346 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
7347 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
7348 	}
7349 }
7350 
7351 
7352 static void autostart_arrays(int part)
7353 {
7354 	mdk_rdev_t *rdev;
7355 	struct detected_devices_node *node_detected_dev;
7356 	dev_t dev;
7357 	int i_scanned, i_passed;
7358 
7359 	i_scanned = 0;
7360 	i_passed = 0;
7361 
7362 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
7363 
7364 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
7365 		i_scanned++;
7366 		node_detected_dev = list_entry(all_detected_devices.next,
7367 					struct detected_devices_node, list);
7368 		list_del(&node_detected_dev->list);
7369 		dev = node_detected_dev->dev;
7370 		kfree(node_detected_dev);
7371 		rdev = md_import_device(dev,0, 90);
7372 		if (IS_ERR(rdev))
7373 			continue;
7374 
7375 		if (test_bit(Faulty, &rdev->flags)) {
7376 			MD_BUG();
7377 			continue;
7378 		}
7379 		set_bit(AutoDetected, &rdev->flags);
7380 		list_add(&rdev->same_set, &pending_raid_disks);
7381 		i_passed++;
7382 	}
7383 
7384 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
7385 						i_scanned, i_passed);
7386 
7387 	autorun_devices(part);
7388 }
7389 
7390 #endif /* !MODULE */
7391 
7392 static __exit void md_exit(void)
7393 {
7394 	mddev_t *mddev;
7395 	struct list_head *tmp;
7396 
7397 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
7398 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
7399 
7400 	unregister_blkdev(MD_MAJOR,"md");
7401 	unregister_blkdev(mdp_major, "mdp");
7402 	unregister_reboot_notifier(&md_notifier);
7403 	unregister_sysctl_table(raid_table_header);
7404 	remove_proc_entry("mdstat", NULL);
7405 	for_each_mddev(mddev, tmp) {
7406 		export_array(mddev);
7407 		mddev->hold_active = 0;
7408 	}
7409 	destroy_workqueue(md_misc_wq);
7410 	destroy_workqueue(md_wq);
7411 }
7412 
7413 subsys_initcall(md_init);
7414 module_exit(md_exit)
7415 
7416 static int get_ro(char *buffer, struct kernel_param *kp)
7417 {
7418 	return sprintf(buffer, "%d", start_readonly);
7419 }
7420 static int set_ro(const char *val, struct kernel_param *kp)
7421 {
7422 	char *e;
7423 	int num = simple_strtoul(val, &e, 10);
7424 	if (*val && (*e == '\0' || *e == '\n')) {
7425 		start_readonly = num;
7426 		return 0;
7427 	}
7428 	return -EINVAL;
7429 }
7430 
7431 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
7432 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
7433 
7434 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
7435 
7436 EXPORT_SYMBOL(register_md_personality);
7437 EXPORT_SYMBOL(unregister_md_personality);
7438 EXPORT_SYMBOL(md_error);
7439 EXPORT_SYMBOL(md_done_sync);
7440 EXPORT_SYMBOL(md_write_start);
7441 EXPORT_SYMBOL(md_write_end);
7442 EXPORT_SYMBOL(md_register_thread);
7443 EXPORT_SYMBOL(md_unregister_thread);
7444 EXPORT_SYMBOL(md_wakeup_thread);
7445 EXPORT_SYMBOL(md_check_recovery);
7446 MODULE_LICENSE("GPL");
7447 MODULE_DESCRIPTION("MD RAID framework");
7448 MODULE_ALIAS("md");
7449 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
7450