xref: /linux/drivers/md/md.c (revision c116cc94969447f44fd7205a027084ceebe90d34)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/blkdev.h>
37 #include <linux/sysctl.h>
38 #include <linux/seq_file.h>
39 #include <linux/fs.h>
40 #include <linux/poll.h>
41 #include <linux/ctype.h>
42 #include <linux/string.h>
43 #include <linux/hdreg.h>
44 #include <linux/proc_fs.h>
45 #include <linux/random.h>
46 #include <linux/module.h>
47 #include <linux/reboot.h>
48 #include <linux/file.h>
49 #include <linux/compat.h>
50 #include <linux/delay.h>
51 #include <linux/raid/md_p.h>
52 #include <linux/raid/md_u.h>
53 #include <linux/slab.h>
54 #include "md.h"
55 #include "bitmap.h"
56 
57 #ifndef MODULE
58 static void autostart_arrays(int part);
59 #endif
60 
61 /* pers_list is a list of registered personalities protected
62  * by pers_lock.
63  * pers_lock does extra service to protect accesses to
64  * mddev->thread when the mutex cannot be held.
65  */
66 static LIST_HEAD(pers_list);
67 static DEFINE_SPINLOCK(pers_lock);
68 
69 static void md_print_devices(void);
70 
71 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
72 static struct workqueue_struct *md_wq;
73 static struct workqueue_struct *md_misc_wq;
74 
75 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
76 
77 /*
78  * Default number of read corrections we'll attempt on an rdev
79  * before ejecting it from the array. We divide the read error
80  * count by 2 for every hour elapsed between read errors.
81  */
82 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
83 /*
84  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
85  * is 1000 KB/sec, so the extra system load does not show up that much.
86  * Increase it if you want to have more _guaranteed_ speed. Note that
87  * the RAID driver will use the maximum available bandwidth if the IO
88  * subsystem is idle. There is also an 'absolute maximum' reconstruction
89  * speed limit - in case reconstruction slows down your system despite
90  * idle IO detection.
91  *
92  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
93  * or /sys/block/mdX/md/sync_speed_{min,max}
94  */
95 
96 static int sysctl_speed_limit_min = 1000;
97 static int sysctl_speed_limit_max = 200000;
98 static inline int speed_min(struct mddev *mddev)
99 {
100 	return mddev->sync_speed_min ?
101 		mddev->sync_speed_min : sysctl_speed_limit_min;
102 }
103 
104 static inline int speed_max(struct mddev *mddev)
105 {
106 	return mddev->sync_speed_max ?
107 		mddev->sync_speed_max : sysctl_speed_limit_max;
108 }
109 
110 static struct ctl_table_header *raid_table_header;
111 
112 static ctl_table raid_table[] = {
113 	{
114 		.procname	= "speed_limit_min",
115 		.data		= &sysctl_speed_limit_min,
116 		.maxlen		= sizeof(int),
117 		.mode		= S_IRUGO|S_IWUSR,
118 		.proc_handler	= proc_dointvec,
119 	},
120 	{
121 		.procname	= "speed_limit_max",
122 		.data		= &sysctl_speed_limit_max,
123 		.maxlen		= sizeof(int),
124 		.mode		= S_IRUGO|S_IWUSR,
125 		.proc_handler	= proc_dointvec,
126 	},
127 	{ }
128 };
129 
130 static ctl_table raid_dir_table[] = {
131 	{
132 		.procname	= "raid",
133 		.maxlen		= 0,
134 		.mode		= S_IRUGO|S_IXUGO,
135 		.child		= raid_table,
136 	},
137 	{ }
138 };
139 
140 static ctl_table raid_root_table[] = {
141 	{
142 		.procname	= "dev",
143 		.maxlen		= 0,
144 		.mode		= 0555,
145 		.child		= raid_dir_table,
146 	},
147 	{  }
148 };
149 
150 static const struct block_device_operations md_fops;
151 
152 static int start_readonly;
153 
154 /* bio_clone_mddev
155  * like bio_clone, but with a local bio set
156  */
157 
158 static void mddev_bio_destructor(struct bio *bio)
159 {
160 	struct mddev *mddev, **mddevp;
161 
162 	mddevp = (void*)bio;
163 	mddev = mddevp[-1];
164 
165 	bio_free(bio, mddev->bio_set);
166 }
167 
168 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
169 			    struct mddev *mddev)
170 {
171 	struct bio *b;
172 	struct mddev **mddevp;
173 
174 	if (!mddev || !mddev->bio_set)
175 		return bio_alloc(gfp_mask, nr_iovecs);
176 
177 	b = bio_alloc_bioset(gfp_mask, nr_iovecs,
178 			     mddev->bio_set);
179 	if (!b)
180 		return NULL;
181 	mddevp = (void*)b;
182 	mddevp[-1] = mddev;
183 	b->bi_destructor = mddev_bio_destructor;
184 	return b;
185 }
186 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
187 
188 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
189 			    struct mddev *mddev)
190 {
191 	struct bio *b;
192 	struct mddev **mddevp;
193 
194 	if (!mddev || !mddev->bio_set)
195 		return bio_clone(bio, gfp_mask);
196 
197 	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
198 			     mddev->bio_set);
199 	if (!b)
200 		return NULL;
201 	mddevp = (void*)b;
202 	mddevp[-1] = mddev;
203 	b->bi_destructor = mddev_bio_destructor;
204 	__bio_clone(b, bio);
205 	if (bio_integrity(bio)) {
206 		int ret;
207 
208 		ret = bio_integrity_clone(b, bio, gfp_mask, mddev->bio_set);
209 
210 		if (ret < 0) {
211 			bio_put(b);
212 			return NULL;
213 		}
214 	}
215 
216 	return b;
217 }
218 EXPORT_SYMBOL_GPL(bio_clone_mddev);
219 
220 void md_trim_bio(struct bio *bio, int offset, int size)
221 {
222 	/* 'bio' is a cloned bio which we need to trim to match
223 	 * the given offset and size.
224 	 * This requires adjusting bi_sector, bi_size, and bi_io_vec
225 	 */
226 	int i;
227 	struct bio_vec *bvec;
228 	int sofar = 0;
229 
230 	size <<= 9;
231 	if (offset == 0 && size == bio->bi_size)
232 		return;
233 
234 	bio->bi_sector += offset;
235 	bio->bi_size = size;
236 	offset <<= 9;
237 	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
238 
239 	while (bio->bi_idx < bio->bi_vcnt &&
240 	       bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
241 		/* remove this whole bio_vec */
242 		offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
243 		bio->bi_idx++;
244 	}
245 	if (bio->bi_idx < bio->bi_vcnt) {
246 		bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
247 		bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
248 	}
249 	/* avoid any complications with bi_idx being non-zero*/
250 	if (bio->bi_idx) {
251 		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
252 			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
253 		bio->bi_vcnt -= bio->bi_idx;
254 		bio->bi_idx = 0;
255 	}
256 	/* Make sure vcnt and last bv are not too big */
257 	bio_for_each_segment(bvec, bio, i) {
258 		if (sofar + bvec->bv_len > size)
259 			bvec->bv_len = size - sofar;
260 		if (bvec->bv_len == 0) {
261 			bio->bi_vcnt = i;
262 			break;
263 		}
264 		sofar += bvec->bv_len;
265 	}
266 }
267 EXPORT_SYMBOL_GPL(md_trim_bio);
268 
269 /*
270  * We have a system wide 'event count' that is incremented
271  * on any 'interesting' event, and readers of /proc/mdstat
272  * can use 'poll' or 'select' to find out when the event
273  * count increases.
274  *
275  * Events are:
276  *  start array, stop array, error, add device, remove device,
277  *  start build, activate spare
278  */
279 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
280 static atomic_t md_event_count;
281 void md_new_event(struct mddev *mddev)
282 {
283 	atomic_inc(&md_event_count);
284 	wake_up(&md_event_waiters);
285 }
286 EXPORT_SYMBOL_GPL(md_new_event);
287 
288 /* Alternate version that can be called from interrupts
289  * when calling sysfs_notify isn't needed.
290  */
291 static void md_new_event_inintr(struct mddev *mddev)
292 {
293 	atomic_inc(&md_event_count);
294 	wake_up(&md_event_waiters);
295 }
296 
297 /*
298  * Enables to iterate over all existing md arrays
299  * all_mddevs_lock protects this list.
300  */
301 static LIST_HEAD(all_mddevs);
302 static DEFINE_SPINLOCK(all_mddevs_lock);
303 
304 
305 /*
306  * iterates through all used mddevs in the system.
307  * We take care to grab the all_mddevs_lock whenever navigating
308  * the list, and to always hold a refcount when unlocked.
309  * Any code which breaks out of this loop while own
310  * a reference to the current mddev and must mddev_put it.
311  */
312 #define for_each_mddev(_mddev,_tmp)					\
313 									\
314 	for (({ spin_lock(&all_mddevs_lock); 				\
315 		_tmp = all_mddevs.next;					\
316 		_mddev = NULL;});					\
317 	     ({ if (_tmp != &all_mddevs)				\
318 			mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
319 		spin_unlock(&all_mddevs_lock);				\
320 		if (_mddev) mddev_put(_mddev);				\
321 		_mddev = list_entry(_tmp, struct mddev, all_mddevs);	\
322 		_tmp != &all_mddevs;});					\
323 	     ({ spin_lock(&all_mddevs_lock);				\
324 		_tmp = _tmp->next;})					\
325 		)
326 
327 
328 /* Rather than calling directly into the personality make_request function,
329  * IO requests come here first so that we can check if the device is
330  * being suspended pending a reconfiguration.
331  * We hold a refcount over the call to ->make_request.  By the time that
332  * call has finished, the bio has been linked into some internal structure
333  * and so is visible to ->quiesce(), so we don't need the refcount any more.
334  */
335 static void md_make_request(struct request_queue *q, struct bio *bio)
336 {
337 	const int rw = bio_data_dir(bio);
338 	struct mddev *mddev = q->queuedata;
339 	int cpu;
340 	unsigned int sectors;
341 
342 	if (mddev == NULL || mddev->pers == NULL
343 	    || !mddev->ready) {
344 		bio_io_error(bio);
345 		return;
346 	}
347 	smp_rmb(); /* Ensure implications of  'active' are visible */
348 	rcu_read_lock();
349 	if (mddev->suspended) {
350 		DEFINE_WAIT(__wait);
351 		for (;;) {
352 			prepare_to_wait(&mddev->sb_wait, &__wait,
353 					TASK_UNINTERRUPTIBLE);
354 			if (!mddev->suspended)
355 				break;
356 			rcu_read_unlock();
357 			schedule();
358 			rcu_read_lock();
359 		}
360 		finish_wait(&mddev->sb_wait, &__wait);
361 	}
362 	atomic_inc(&mddev->active_io);
363 	rcu_read_unlock();
364 
365 	/*
366 	 * save the sectors now since our bio can
367 	 * go away inside make_request
368 	 */
369 	sectors = bio_sectors(bio);
370 	mddev->pers->make_request(mddev, bio);
371 
372 	cpu = part_stat_lock();
373 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
374 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
375 	part_stat_unlock();
376 
377 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
378 		wake_up(&mddev->sb_wait);
379 }
380 
381 /* mddev_suspend makes sure no new requests are submitted
382  * to the device, and that any requests that have been submitted
383  * are completely handled.
384  * Once ->stop is called and completes, the module will be completely
385  * unused.
386  */
387 void mddev_suspend(struct mddev *mddev)
388 {
389 	BUG_ON(mddev->suspended);
390 	mddev->suspended = 1;
391 	synchronize_rcu();
392 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
393 	mddev->pers->quiesce(mddev, 1);
394 
395 	del_timer_sync(&mddev->safemode_timer);
396 }
397 EXPORT_SYMBOL_GPL(mddev_suspend);
398 
399 void mddev_resume(struct mddev *mddev)
400 {
401 	mddev->suspended = 0;
402 	wake_up(&mddev->sb_wait);
403 	mddev->pers->quiesce(mddev, 0);
404 
405 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
406 	md_wakeup_thread(mddev->thread);
407 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
408 }
409 EXPORT_SYMBOL_GPL(mddev_resume);
410 
411 int mddev_congested(struct mddev *mddev, int bits)
412 {
413 	return mddev->suspended;
414 }
415 EXPORT_SYMBOL(mddev_congested);
416 
417 /*
418  * Generic flush handling for md
419  */
420 
421 static void md_end_flush(struct bio *bio, int err)
422 {
423 	struct md_rdev *rdev = bio->bi_private;
424 	struct mddev *mddev = rdev->mddev;
425 
426 	rdev_dec_pending(rdev, mddev);
427 
428 	if (atomic_dec_and_test(&mddev->flush_pending)) {
429 		/* The pre-request flush has finished */
430 		queue_work(md_wq, &mddev->flush_work);
431 	}
432 	bio_put(bio);
433 }
434 
435 static void md_submit_flush_data(struct work_struct *ws);
436 
437 static void submit_flushes(struct work_struct *ws)
438 {
439 	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
440 	struct md_rdev *rdev;
441 
442 	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
443 	atomic_set(&mddev->flush_pending, 1);
444 	rcu_read_lock();
445 	rdev_for_each_rcu(rdev, mddev)
446 		if (rdev->raid_disk >= 0 &&
447 		    !test_bit(Faulty, &rdev->flags)) {
448 			/* Take two references, one is dropped
449 			 * when request finishes, one after
450 			 * we reclaim rcu_read_lock
451 			 */
452 			struct bio *bi;
453 			atomic_inc(&rdev->nr_pending);
454 			atomic_inc(&rdev->nr_pending);
455 			rcu_read_unlock();
456 			bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
457 			bi->bi_end_io = md_end_flush;
458 			bi->bi_private = rdev;
459 			bi->bi_bdev = rdev->bdev;
460 			atomic_inc(&mddev->flush_pending);
461 			submit_bio(WRITE_FLUSH, bi);
462 			rcu_read_lock();
463 			rdev_dec_pending(rdev, mddev);
464 		}
465 	rcu_read_unlock();
466 	if (atomic_dec_and_test(&mddev->flush_pending))
467 		queue_work(md_wq, &mddev->flush_work);
468 }
469 
470 static void md_submit_flush_data(struct work_struct *ws)
471 {
472 	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
473 	struct bio *bio = mddev->flush_bio;
474 
475 	if (bio->bi_size == 0)
476 		/* an empty barrier - all done */
477 		bio_endio(bio, 0);
478 	else {
479 		bio->bi_rw &= ~REQ_FLUSH;
480 		mddev->pers->make_request(mddev, bio);
481 	}
482 
483 	mddev->flush_bio = NULL;
484 	wake_up(&mddev->sb_wait);
485 }
486 
487 void md_flush_request(struct mddev *mddev, struct bio *bio)
488 {
489 	spin_lock_irq(&mddev->write_lock);
490 	wait_event_lock_irq(mddev->sb_wait,
491 			    !mddev->flush_bio,
492 			    mddev->write_lock, /*nothing*/);
493 	mddev->flush_bio = bio;
494 	spin_unlock_irq(&mddev->write_lock);
495 
496 	INIT_WORK(&mddev->flush_work, submit_flushes);
497 	queue_work(md_wq, &mddev->flush_work);
498 }
499 EXPORT_SYMBOL(md_flush_request);
500 
501 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
502 {
503 	struct mddev *mddev = cb->data;
504 	md_wakeup_thread(mddev->thread);
505 	kfree(cb);
506 }
507 EXPORT_SYMBOL(md_unplug);
508 
509 static inline struct mddev *mddev_get(struct mddev *mddev)
510 {
511 	atomic_inc(&mddev->active);
512 	return mddev;
513 }
514 
515 static void mddev_delayed_delete(struct work_struct *ws);
516 
517 static void mddev_put(struct mddev *mddev)
518 {
519 	struct bio_set *bs = NULL;
520 
521 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
522 		return;
523 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
524 	    mddev->ctime == 0 && !mddev->hold_active) {
525 		/* Array is not configured at all, and not held active,
526 		 * so destroy it */
527 		list_del_init(&mddev->all_mddevs);
528 		bs = mddev->bio_set;
529 		mddev->bio_set = NULL;
530 		if (mddev->gendisk) {
531 			/* We did a probe so need to clean up.  Call
532 			 * queue_work inside the spinlock so that
533 			 * flush_workqueue() after mddev_find will
534 			 * succeed in waiting for the work to be done.
535 			 */
536 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
537 			queue_work(md_misc_wq, &mddev->del_work);
538 		} else
539 			kfree(mddev);
540 	}
541 	spin_unlock(&all_mddevs_lock);
542 	if (bs)
543 		bioset_free(bs);
544 }
545 
546 void mddev_init(struct mddev *mddev)
547 {
548 	mutex_init(&mddev->open_mutex);
549 	mutex_init(&mddev->reconfig_mutex);
550 	mutex_init(&mddev->bitmap_info.mutex);
551 	INIT_LIST_HEAD(&mddev->disks);
552 	INIT_LIST_HEAD(&mddev->all_mddevs);
553 	init_timer(&mddev->safemode_timer);
554 	atomic_set(&mddev->active, 1);
555 	atomic_set(&mddev->openers, 0);
556 	atomic_set(&mddev->active_io, 0);
557 	spin_lock_init(&mddev->write_lock);
558 	atomic_set(&mddev->flush_pending, 0);
559 	init_waitqueue_head(&mddev->sb_wait);
560 	init_waitqueue_head(&mddev->recovery_wait);
561 	mddev->reshape_position = MaxSector;
562 	mddev->reshape_backwards = 0;
563 	mddev->resync_min = 0;
564 	mddev->resync_max = MaxSector;
565 	mddev->level = LEVEL_NONE;
566 }
567 EXPORT_SYMBOL_GPL(mddev_init);
568 
569 static struct mddev * mddev_find(dev_t unit)
570 {
571 	struct mddev *mddev, *new = NULL;
572 
573 	if (unit && MAJOR(unit) != MD_MAJOR)
574 		unit &= ~((1<<MdpMinorShift)-1);
575 
576  retry:
577 	spin_lock(&all_mddevs_lock);
578 
579 	if (unit) {
580 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
581 			if (mddev->unit == unit) {
582 				mddev_get(mddev);
583 				spin_unlock(&all_mddevs_lock);
584 				kfree(new);
585 				return mddev;
586 			}
587 
588 		if (new) {
589 			list_add(&new->all_mddevs, &all_mddevs);
590 			spin_unlock(&all_mddevs_lock);
591 			new->hold_active = UNTIL_IOCTL;
592 			return new;
593 		}
594 	} else if (new) {
595 		/* find an unused unit number */
596 		static int next_minor = 512;
597 		int start = next_minor;
598 		int is_free = 0;
599 		int dev = 0;
600 		while (!is_free) {
601 			dev = MKDEV(MD_MAJOR, next_minor);
602 			next_minor++;
603 			if (next_minor > MINORMASK)
604 				next_minor = 0;
605 			if (next_minor == start) {
606 				/* Oh dear, all in use. */
607 				spin_unlock(&all_mddevs_lock);
608 				kfree(new);
609 				return NULL;
610 			}
611 
612 			is_free = 1;
613 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
614 				if (mddev->unit == dev) {
615 					is_free = 0;
616 					break;
617 				}
618 		}
619 		new->unit = dev;
620 		new->md_minor = MINOR(dev);
621 		new->hold_active = UNTIL_STOP;
622 		list_add(&new->all_mddevs, &all_mddevs);
623 		spin_unlock(&all_mddevs_lock);
624 		return new;
625 	}
626 	spin_unlock(&all_mddevs_lock);
627 
628 	new = kzalloc(sizeof(*new), GFP_KERNEL);
629 	if (!new)
630 		return NULL;
631 
632 	new->unit = unit;
633 	if (MAJOR(unit) == MD_MAJOR)
634 		new->md_minor = MINOR(unit);
635 	else
636 		new->md_minor = MINOR(unit) >> MdpMinorShift;
637 
638 	mddev_init(new);
639 
640 	goto retry;
641 }
642 
643 static inline int mddev_lock(struct mddev * mddev)
644 {
645 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
646 }
647 
648 static inline int mddev_is_locked(struct mddev *mddev)
649 {
650 	return mutex_is_locked(&mddev->reconfig_mutex);
651 }
652 
653 static inline int mddev_trylock(struct mddev * mddev)
654 {
655 	return mutex_trylock(&mddev->reconfig_mutex);
656 }
657 
658 static struct attribute_group md_redundancy_group;
659 
660 static void mddev_unlock(struct mddev * mddev)
661 {
662 	if (mddev->to_remove) {
663 		/* These cannot be removed under reconfig_mutex as
664 		 * an access to the files will try to take reconfig_mutex
665 		 * while holding the file unremovable, which leads to
666 		 * a deadlock.
667 		 * So hold set sysfs_active while the remove in happeing,
668 		 * and anything else which might set ->to_remove or my
669 		 * otherwise change the sysfs namespace will fail with
670 		 * -EBUSY if sysfs_active is still set.
671 		 * We set sysfs_active under reconfig_mutex and elsewhere
672 		 * test it under the same mutex to ensure its correct value
673 		 * is seen.
674 		 */
675 		struct attribute_group *to_remove = mddev->to_remove;
676 		mddev->to_remove = NULL;
677 		mddev->sysfs_active = 1;
678 		mutex_unlock(&mddev->reconfig_mutex);
679 
680 		if (mddev->kobj.sd) {
681 			if (to_remove != &md_redundancy_group)
682 				sysfs_remove_group(&mddev->kobj, to_remove);
683 			if (mddev->pers == NULL ||
684 			    mddev->pers->sync_request == NULL) {
685 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
686 				if (mddev->sysfs_action)
687 					sysfs_put(mddev->sysfs_action);
688 				mddev->sysfs_action = NULL;
689 			}
690 		}
691 		mddev->sysfs_active = 0;
692 	} else
693 		mutex_unlock(&mddev->reconfig_mutex);
694 
695 	/* As we've dropped the mutex we need a spinlock to
696 	 * make sure the thread doesn't disappear
697 	 */
698 	spin_lock(&pers_lock);
699 	md_wakeup_thread(mddev->thread);
700 	spin_unlock(&pers_lock);
701 }
702 
703 static struct md_rdev * find_rdev_nr(struct mddev *mddev, int nr)
704 {
705 	struct md_rdev *rdev;
706 
707 	rdev_for_each(rdev, mddev)
708 		if (rdev->desc_nr == nr)
709 			return rdev;
710 
711 	return NULL;
712 }
713 
714 static struct md_rdev * find_rdev(struct mddev * mddev, dev_t dev)
715 {
716 	struct md_rdev *rdev;
717 
718 	rdev_for_each(rdev, mddev)
719 		if (rdev->bdev->bd_dev == dev)
720 			return rdev;
721 
722 	return NULL;
723 }
724 
725 static struct md_personality *find_pers(int level, char *clevel)
726 {
727 	struct md_personality *pers;
728 	list_for_each_entry(pers, &pers_list, list) {
729 		if (level != LEVEL_NONE && pers->level == level)
730 			return pers;
731 		if (strcmp(pers->name, clevel)==0)
732 			return pers;
733 	}
734 	return NULL;
735 }
736 
737 /* return the offset of the super block in 512byte sectors */
738 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
739 {
740 	sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
741 	return MD_NEW_SIZE_SECTORS(num_sectors);
742 }
743 
744 static int alloc_disk_sb(struct md_rdev * rdev)
745 {
746 	if (rdev->sb_page)
747 		MD_BUG();
748 
749 	rdev->sb_page = alloc_page(GFP_KERNEL);
750 	if (!rdev->sb_page) {
751 		printk(KERN_ALERT "md: out of memory.\n");
752 		return -ENOMEM;
753 	}
754 
755 	return 0;
756 }
757 
758 void md_rdev_clear(struct md_rdev *rdev)
759 {
760 	if (rdev->sb_page) {
761 		put_page(rdev->sb_page);
762 		rdev->sb_loaded = 0;
763 		rdev->sb_page = NULL;
764 		rdev->sb_start = 0;
765 		rdev->sectors = 0;
766 	}
767 	if (rdev->bb_page) {
768 		put_page(rdev->bb_page);
769 		rdev->bb_page = NULL;
770 	}
771 	kfree(rdev->badblocks.page);
772 	rdev->badblocks.page = NULL;
773 }
774 EXPORT_SYMBOL_GPL(md_rdev_clear);
775 
776 static void super_written(struct bio *bio, int error)
777 {
778 	struct md_rdev *rdev = bio->bi_private;
779 	struct mddev *mddev = rdev->mddev;
780 
781 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
782 		printk("md: super_written gets error=%d, uptodate=%d\n",
783 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
784 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
785 		md_error(mddev, rdev);
786 	}
787 
788 	if (atomic_dec_and_test(&mddev->pending_writes))
789 		wake_up(&mddev->sb_wait);
790 	bio_put(bio);
791 }
792 
793 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
794 		   sector_t sector, int size, struct page *page)
795 {
796 	/* write first size bytes of page to sector of rdev
797 	 * Increment mddev->pending_writes before returning
798 	 * and decrement it on completion, waking up sb_wait
799 	 * if zero is reached.
800 	 * If an error occurred, call md_error
801 	 */
802 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
803 
804 	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
805 	bio->bi_sector = sector;
806 	bio_add_page(bio, page, size, 0);
807 	bio->bi_private = rdev;
808 	bio->bi_end_io = super_written;
809 
810 	atomic_inc(&mddev->pending_writes);
811 	submit_bio(WRITE_FLUSH_FUA, bio);
812 }
813 
814 void md_super_wait(struct mddev *mddev)
815 {
816 	/* wait for all superblock writes that were scheduled to complete */
817 	DEFINE_WAIT(wq);
818 	for(;;) {
819 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
820 		if (atomic_read(&mddev->pending_writes)==0)
821 			break;
822 		schedule();
823 	}
824 	finish_wait(&mddev->sb_wait, &wq);
825 }
826 
827 static void bi_complete(struct bio *bio, int error)
828 {
829 	complete((struct completion*)bio->bi_private);
830 }
831 
832 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
833 		 struct page *page, int rw, bool metadata_op)
834 {
835 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
836 	struct completion event;
837 	int ret;
838 
839 	rw |= REQ_SYNC;
840 
841 	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
842 		rdev->meta_bdev : rdev->bdev;
843 	if (metadata_op)
844 		bio->bi_sector = sector + rdev->sb_start;
845 	else if (rdev->mddev->reshape_position != MaxSector &&
846 		 (rdev->mddev->reshape_backwards ==
847 		  (sector >= rdev->mddev->reshape_position)))
848 		bio->bi_sector = sector + rdev->new_data_offset;
849 	else
850 		bio->bi_sector = sector + rdev->data_offset;
851 	bio_add_page(bio, page, size, 0);
852 	init_completion(&event);
853 	bio->bi_private = &event;
854 	bio->bi_end_io = bi_complete;
855 	submit_bio(rw, bio);
856 	wait_for_completion(&event);
857 
858 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
859 	bio_put(bio);
860 	return ret;
861 }
862 EXPORT_SYMBOL_GPL(sync_page_io);
863 
864 static int read_disk_sb(struct md_rdev * rdev, int size)
865 {
866 	char b[BDEVNAME_SIZE];
867 	if (!rdev->sb_page) {
868 		MD_BUG();
869 		return -EINVAL;
870 	}
871 	if (rdev->sb_loaded)
872 		return 0;
873 
874 
875 	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
876 		goto fail;
877 	rdev->sb_loaded = 1;
878 	return 0;
879 
880 fail:
881 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
882 		bdevname(rdev->bdev,b));
883 	return -EINVAL;
884 }
885 
886 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
887 {
888 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
889 		sb1->set_uuid1 == sb2->set_uuid1 &&
890 		sb1->set_uuid2 == sb2->set_uuid2 &&
891 		sb1->set_uuid3 == sb2->set_uuid3;
892 }
893 
894 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
895 {
896 	int ret;
897 	mdp_super_t *tmp1, *tmp2;
898 
899 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
900 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
901 
902 	if (!tmp1 || !tmp2) {
903 		ret = 0;
904 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
905 		goto abort;
906 	}
907 
908 	*tmp1 = *sb1;
909 	*tmp2 = *sb2;
910 
911 	/*
912 	 * nr_disks is not constant
913 	 */
914 	tmp1->nr_disks = 0;
915 	tmp2->nr_disks = 0;
916 
917 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
918 abort:
919 	kfree(tmp1);
920 	kfree(tmp2);
921 	return ret;
922 }
923 
924 
925 static u32 md_csum_fold(u32 csum)
926 {
927 	csum = (csum & 0xffff) + (csum >> 16);
928 	return (csum & 0xffff) + (csum >> 16);
929 }
930 
931 static unsigned int calc_sb_csum(mdp_super_t * sb)
932 {
933 	u64 newcsum = 0;
934 	u32 *sb32 = (u32*)sb;
935 	int i;
936 	unsigned int disk_csum, csum;
937 
938 	disk_csum = sb->sb_csum;
939 	sb->sb_csum = 0;
940 
941 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
942 		newcsum += sb32[i];
943 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
944 
945 
946 #ifdef CONFIG_ALPHA
947 	/* This used to use csum_partial, which was wrong for several
948 	 * reasons including that different results are returned on
949 	 * different architectures.  It isn't critical that we get exactly
950 	 * the same return value as before (we always csum_fold before
951 	 * testing, and that removes any differences).  However as we
952 	 * know that csum_partial always returned a 16bit value on
953 	 * alphas, do a fold to maximise conformity to previous behaviour.
954 	 */
955 	sb->sb_csum = md_csum_fold(disk_csum);
956 #else
957 	sb->sb_csum = disk_csum;
958 #endif
959 	return csum;
960 }
961 
962 
963 /*
964  * Handle superblock details.
965  * We want to be able to handle multiple superblock formats
966  * so we have a common interface to them all, and an array of
967  * different handlers.
968  * We rely on user-space to write the initial superblock, and support
969  * reading and updating of superblocks.
970  * Interface methods are:
971  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
972  *      loads and validates a superblock on dev.
973  *      if refdev != NULL, compare superblocks on both devices
974  *    Return:
975  *      0 - dev has a superblock that is compatible with refdev
976  *      1 - dev has a superblock that is compatible and newer than refdev
977  *          so dev should be used as the refdev in future
978  *     -EINVAL superblock incompatible or invalid
979  *     -othererror e.g. -EIO
980  *
981  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
982  *      Verify that dev is acceptable into mddev.
983  *       The first time, mddev->raid_disks will be 0, and data from
984  *       dev should be merged in.  Subsequent calls check that dev
985  *       is new enough.  Return 0 or -EINVAL
986  *
987  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
988  *     Update the superblock for rdev with data in mddev
989  *     This does not write to disc.
990  *
991  */
992 
993 struct super_type  {
994 	char		    *name;
995 	struct module	    *owner;
996 	int		    (*load_super)(struct md_rdev *rdev,
997 					  struct md_rdev *refdev,
998 					  int minor_version);
999 	int		    (*validate_super)(struct mddev *mddev,
1000 					      struct md_rdev *rdev);
1001 	void		    (*sync_super)(struct mddev *mddev,
1002 					  struct md_rdev *rdev);
1003 	unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
1004 						sector_t num_sectors);
1005 	int		    (*allow_new_offset)(struct md_rdev *rdev,
1006 						unsigned long long new_offset);
1007 };
1008 
1009 /*
1010  * Check that the given mddev has no bitmap.
1011  *
1012  * This function is called from the run method of all personalities that do not
1013  * support bitmaps. It prints an error message and returns non-zero if mddev
1014  * has a bitmap. Otherwise, it returns 0.
1015  *
1016  */
1017 int md_check_no_bitmap(struct mddev *mddev)
1018 {
1019 	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
1020 		return 0;
1021 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
1022 		mdname(mddev), mddev->pers->name);
1023 	return 1;
1024 }
1025 EXPORT_SYMBOL(md_check_no_bitmap);
1026 
1027 /*
1028  * load_super for 0.90.0
1029  */
1030 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1031 {
1032 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1033 	mdp_super_t *sb;
1034 	int ret;
1035 
1036 	/*
1037 	 * Calculate the position of the superblock (512byte sectors),
1038 	 * it's at the end of the disk.
1039 	 *
1040 	 * It also happens to be a multiple of 4Kb.
1041 	 */
1042 	rdev->sb_start = calc_dev_sboffset(rdev);
1043 
1044 	ret = read_disk_sb(rdev, MD_SB_BYTES);
1045 	if (ret) return ret;
1046 
1047 	ret = -EINVAL;
1048 
1049 	bdevname(rdev->bdev, b);
1050 	sb = page_address(rdev->sb_page);
1051 
1052 	if (sb->md_magic != MD_SB_MAGIC) {
1053 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
1054 		       b);
1055 		goto abort;
1056 	}
1057 
1058 	if (sb->major_version != 0 ||
1059 	    sb->minor_version < 90 ||
1060 	    sb->minor_version > 91) {
1061 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1062 			sb->major_version, sb->minor_version,
1063 			b);
1064 		goto abort;
1065 	}
1066 
1067 	if (sb->raid_disks <= 0)
1068 		goto abort;
1069 
1070 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1071 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1072 			b);
1073 		goto abort;
1074 	}
1075 
1076 	rdev->preferred_minor = sb->md_minor;
1077 	rdev->data_offset = 0;
1078 	rdev->new_data_offset = 0;
1079 	rdev->sb_size = MD_SB_BYTES;
1080 	rdev->badblocks.shift = -1;
1081 
1082 	if (sb->level == LEVEL_MULTIPATH)
1083 		rdev->desc_nr = -1;
1084 	else
1085 		rdev->desc_nr = sb->this_disk.number;
1086 
1087 	if (!refdev) {
1088 		ret = 1;
1089 	} else {
1090 		__u64 ev1, ev2;
1091 		mdp_super_t *refsb = page_address(refdev->sb_page);
1092 		if (!uuid_equal(refsb, sb)) {
1093 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
1094 				b, bdevname(refdev->bdev,b2));
1095 			goto abort;
1096 		}
1097 		if (!sb_equal(refsb, sb)) {
1098 			printk(KERN_WARNING "md: %s has same UUID"
1099 			       " but different superblock to %s\n",
1100 			       b, bdevname(refdev->bdev, b2));
1101 			goto abort;
1102 		}
1103 		ev1 = md_event(sb);
1104 		ev2 = md_event(refsb);
1105 		if (ev1 > ev2)
1106 			ret = 1;
1107 		else
1108 			ret = 0;
1109 	}
1110 	rdev->sectors = rdev->sb_start;
1111 	/* Limit to 4TB as metadata cannot record more than that */
1112 	if (rdev->sectors >= (2ULL << 32))
1113 		rdev->sectors = (2ULL << 32) - 2;
1114 
1115 	if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1116 		/* "this cannot possibly happen" ... */
1117 		ret = -EINVAL;
1118 
1119  abort:
1120 	return ret;
1121 }
1122 
1123 /*
1124  * validate_super for 0.90.0
1125  */
1126 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1127 {
1128 	mdp_disk_t *desc;
1129 	mdp_super_t *sb = page_address(rdev->sb_page);
1130 	__u64 ev1 = md_event(sb);
1131 
1132 	rdev->raid_disk = -1;
1133 	clear_bit(Faulty, &rdev->flags);
1134 	clear_bit(In_sync, &rdev->flags);
1135 	clear_bit(WriteMostly, &rdev->flags);
1136 
1137 	if (mddev->raid_disks == 0) {
1138 		mddev->major_version = 0;
1139 		mddev->minor_version = sb->minor_version;
1140 		mddev->patch_version = sb->patch_version;
1141 		mddev->external = 0;
1142 		mddev->chunk_sectors = sb->chunk_size >> 9;
1143 		mddev->ctime = sb->ctime;
1144 		mddev->utime = sb->utime;
1145 		mddev->level = sb->level;
1146 		mddev->clevel[0] = 0;
1147 		mddev->layout = sb->layout;
1148 		mddev->raid_disks = sb->raid_disks;
1149 		mddev->dev_sectors = ((sector_t)sb->size) * 2;
1150 		mddev->events = ev1;
1151 		mddev->bitmap_info.offset = 0;
1152 		mddev->bitmap_info.space = 0;
1153 		/* bitmap can use 60 K after the 4K superblocks */
1154 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1155 		mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1156 		mddev->reshape_backwards = 0;
1157 
1158 		if (mddev->minor_version >= 91) {
1159 			mddev->reshape_position = sb->reshape_position;
1160 			mddev->delta_disks = sb->delta_disks;
1161 			mddev->new_level = sb->new_level;
1162 			mddev->new_layout = sb->new_layout;
1163 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1164 			if (mddev->delta_disks < 0)
1165 				mddev->reshape_backwards = 1;
1166 		} else {
1167 			mddev->reshape_position = MaxSector;
1168 			mddev->delta_disks = 0;
1169 			mddev->new_level = mddev->level;
1170 			mddev->new_layout = mddev->layout;
1171 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1172 		}
1173 
1174 		if (sb->state & (1<<MD_SB_CLEAN))
1175 			mddev->recovery_cp = MaxSector;
1176 		else {
1177 			if (sb->events_hi == sb->cp_events_hi &&
1178 				sb->events_lo == sb->cp_events_lo) {
1179 				mddev->recovery_cp = sb->recovery_cp;
1180 			} else
1181 				mddev->recovery_cp = 0;
1182 		}
1183 
1184 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1185 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1186 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1187 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1188 
1189 		mddev->max_disks = MD_SB_DISKS;
1190 
1191 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1192 		    mddev->bitmap_info.file == NULL) {
1193 			mddev->bitmap_info.offset =
1194 				mddev->bitmap_info.default_offset;
1195 			mddev->bitmap_info.space =
1196 				mddev->bitmap_info.space;
1197 		}
1198 
1199 	} else if (mddev->pers == NULL) {
1200 		/* Insist on good event counter while assembling, except
1201 		 * for spares (which don't need an event count) */
1202 		++ev1;
1203 		if (sb->disks[rdev->desc_nr].state & (
1204 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1205 			if (ev1 < mddev->events)
1206 				return -EINVAL;
1207 	} else if (mddev->bitmap) {
1208 		/* if adding to array with a bitmap, then we can accept an
1209 		 * older device ... but not too old.
1210 		 */
1211 		if (ev1 < mddev->bitmap->events_cleared)
1212 			return 0;
1213 	} else {
1214 		if (ev1 < mddev->events)
1215 			/* just a hot-add of a new device, leave raid_disk at -1 */
1216 			return 0;
1217 	}
1218 
1219 	if (mddev->level != LEVEL_MULTIPATH) {
1220 		desc = sb->disks + rdev->desc_nr;
1221 
1222 		if (desc->state & (1<<MD_DISK_FAULTY))
1223 			set_bit(Faulty, &rdev->flags);
1224 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1225 			    desc->raid_disk < mddev->raid_disks */) {
1226 			set_bit(In_sync, &rdev->flags);
1227 			rdev->raid_disk = desc->raid_disk;
1228 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1229 			/* active but not in sync implies recovery up to
1230 			 * reshape position.  We don't know exactly where
1231 			 * that is, so set to zero for now */
1232 			if (mddev->minor_version >= 91) {
1233 				rdev->recovery_offset = 0;
1234 				rdev->raid_disk = desc->raid_disk;
1235 			}
1236 		}
1237 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1238 			set_bit(WriteMostly, &rdev->flags);
1239 	} else /* MULTIPATH are always insync */
1240 		set_bit(In_sync, &rdev->flags);
1241 	return 0;
1242 }
1243 
1244 /*
1245  * sync_super for 0.90.0
1246  */
1247 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1248 {
1249 	mdp_super_t *sb;
1250 	struct md_rdev *rdev2;
1251 	int next_spare = mddev->raid_disks;
1252 
1253 
1254 	/* make rdev->sb match mddev data..
1255 	 *
1256 	 * 1/ zero out disks
1257 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1258 	 * 3/ any empty disks < next_spare become removed
1259 	 *
1260 	 * disks[0] gets initialised to REMOVED because
1261 	 * we cannot be sure from other fields if it has
1262 	 * been initialised or not.
1263 	 */
1264 	int i;
1265 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1266 
1267 	rdev->sb_size = MD_SB_BYTES;
1268 
1269 	sb = page_address(rdev->sb_page);
1270 
1271 	memset(sb, 0, sizeof(*sb));
1272 
1273 	sb->md_magic = MD_SB_MAGIC;
1274 	sb->major_version = mddev->major_version;
1275 	sb->patch_version = mddev->patch_version;
1276 	sb->gvalid_words  = 0; /* ignored */
1277 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1278 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1279 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1280 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1281 
1282 	sb->ctime = mddev->ctime;
1283 	sb->level = mddev->level;
1284 	sb->size = mddev->dev_sectors / 2;
1285 	sb->raid_disks = mddev->raid_disks;
1286 	sb->md_minor = mddev->md_minor;
1287 	sb->not_persistent = 0;
1288 	sb->utime = mddev->utime;
1289 	sb->state = 0;
1290 	sb->events_hi = (mddev->events>>32);
1291 	sb->events_lo = (u32)mddev->events;
1292 
1293 	if (mddev->reshape_position == MaxSector)
1294 		sb->minor_version = 90;
1295 	else {
1296 		sb->minor_version = 91;
1297 		sb->reshape_position = mddev->reshape_position;
1298 		sb->new_level = mddev->new_level;
1299 		sb->delta_disks = mddev->delta_disks;
1300 		sb->new_layout = mddev->new_layout;
1301 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1302 	}
1303 	mddev->minor_version = sb->minor_version;
1304 	if (mddev->in_sync)
1305 	{
1306 		sb->recovery_cp = mddev->recovery_cp;
1307 		sb->cp_events_hi = (mddev->events>>32);
1308 		sb->cp_events_lo = (u32)mddev->events;
1309 		if (mddev->recovery_cp == MaxSector)
1310 			sb->state = (1<< MD_SB_CLEAN);
1311 	} else
1312 		sb->recovery_cp = 0;
1313 
1314 	sb->layout = mddev->layout;
1315 	sb->chunk_size = mddev->chunk_sectors << 9;
1316 
1317 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1318 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1319 
1320 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1321 	rdev_for_each(rdev2, mddev) {
1322 		mdp_disk_t *d;
1323 		int desc_nr;
1324 		int is_active = test_bit(In_sync, &rdev2->flags);
1325 
1326 		if (rdev2->raid_disk >= 0 &&
1327 		    sb->minor_version >= 91)
1328 			/* we have nowhere to store the recovery_offset,
1329 			 * but if it is not below the reshape_position,
1330 			 * we can piggy-back on that.
1331 			 */
1332 			is_active = 1;
1333 		if (rdev2->raid_disk < 0 ||
1334 		    test_bit(Faulty, &rdev2->flags))
1335 			is_active = 0;
1336 		if (is_active)
1337 			desc_nr = rdev2->raid_disk;
1338 		else
1339 			desc_nr = next_spare++;
1340 		rdev2->desc_nr = desc_nr;
1341 		d = &sb->disks[rdev2->desc_nr];
1342 		nr_disks++;
1343 		d->number = rdev2->desc_nr;
1344 		d->major = MAJOR(rdev2->bdev->bd_dev);
1345 		d->minor = MINOR(rdev2->bdev->bd_dev);
1346 		if (is_active)
1347 			d->raid_disk = rdev2->raid_disk;
1348 		else
1349 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1350 		if (test_bit(Faulty, &rdev2->flags))
1351 			d->state = (1<<MD_DISK_FAULTY);
1352 		else if (is_active) {
1353 			d->state = (1<<MD_DISK_ACTIVE);
1354 			if (test_bit(In_sync, &rdev2->flags))
1355 				d->state |= (1<<MD_DISK_SYNC);
1356 			active++;
1357 			working++;
1358 		} else {
1359 			d->state = 0;
1360 			spare++;
1361 			working++;
1362 		}
1363 		if (test_bit(WriteMostly, &rdev2->flags))
1364 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1365 	}
1366 	/* now set the "removed" and "faulty" bits on any missing devices */
1367 	for (i=0 ; i < mddev->raid_disks ; i++) {
1368 		mdp_disk_t *d = &sb->disks[i];
1369 		if (d->state == 0 && d->number == 0) {
1370 			d->number = i;
1371 			d->raid_disk = i;
1372 			d->state = (1<<MD_DISK_REMOVED);
1373 			d->state |= (1<<MD_DISK_FAULTY);
1374 			failed++;
1375 		}
1376 	}
1377 	sb->nr_disks = nr_disks;
1378 	sb->active_disks = active;
1379 	sb->working_disks = working;
1380 	sb->failed_disks = failed;
1381 	sb->spare_disks = spare;
1382 
1383 	sb->this_disk = sb->disks[rdev->desc_nr];
1384 	sb->sb_csum = calc_sb_csum(sb);
1385 }
1386 
1387 /*
1388  * rdev_size_change for 0.90.0
1389  */
1390 static unsigned long long
1391 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1392 {
1393 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1394 		return 0; /* component must fit device */
1395 	if (rdev->mddev->bitmap_info.offset)
1396 		return 0; /* can't move bitmap */
1397 	rdev->sb_start = calc_dev_sboffset(rdev);
1398 	if (!num_sectors || num_sectors > rdev->sb_start)
1399 		num_sectors = rdev->sb_start;
1400 	/* Limit to 4TB as metadata cannot record more than that.
1401 	 * 4TB == 2^32 KB, or 2*2^32 sectors.
1402 	 */
1403 	if (num_sectors >= (2ULL << 32))
1404 		num_sectors = (2ULL << 32) - 2;
1405 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1406 		       rdev->sb_page);
1407 	md_super_wait(rdev->mddev);
1408 	return num_sectors;
1409 }
1410 
1411 static int
1412 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1413 {
1414 	/* non-zero offset changes not possible with v0.90 */
1415 	return new_offset == 0;
1416 }
1417 
1418 /*
1419  * version 1 superblock
1420  */
1421 
1422 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1423 {
1424 	__le32 disk_csum;
1425 	u32 csum;
1426 	unsigned long long newcsum;
1427 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1428 	__le32 *isuper = (__le32*)sb;
1429 	int i;
1430 
1431 	disk_csum = sb->sb_csum;
1432 	sb->sb_csum = 0;
1433 	newcsum = 0;
1434 	for (i=0; size>=4; size -= 4 )
1435 		newcsum += le32_to_cpu(*isuper++);
1436 
1437 	if (size == 2)
1438 		newcsum += le16_to_cpu(*(__le16*) isuper);
1439 
1440 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1441 	sb->sb_csum = disk_csum;
1442 	return cpu_to_le32(csum);
1443 }
1444 
1445 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1446 			    int acknowledged);
1447 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1448 {
1449 	struct mdp_superblock_1 *sb;
1450 	int ret;
1451 	sector_t sb_start;
1452 	sector_t sectors;
1453 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1454 	int bmask;
1455 
1456 	/*
1457 	 * Calculate the position of the superblock in 512byte sectors.
1458 	 * It is always aligned to a 4K boundary and
1459 	 * depeding on minor_version, it can be:
1460 	 * 0: At least 8K, but less than 12K, from end of device
1461 	 * 1: At start of device
1462 	 * 2: 4K from start of device.
1463 	 */
1464 	switch(minor_version) {
1465 	case 0:
1466 		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1467 		sb_start -= 8*2;
1468 		sb_start &= ~(sector_t)(4*2-1);
1469 		break;
1470 	case 1:
1471 		sb_start = 0;
1472 		break;
1473 	case 2:
1474 		sb_start = 8;
1475 		break;
1476 	default:
1477 		return -EINVAL;
1478 	}
1479 	rdev->sb_start = sb_start;
1480 
1481 	/* superblock is rarely larger than 1K, but it can be larger,
1482 	 * and it is safe to read 4k, so we do that
1483 	 */
1484 	ret = read_disk_sb(rdev, 4096);
1485 	if (ret) return ret;
1486 
1487 
1488 	sb = page_address(rdev->sb_page);
1489 
1490 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1491 	    sb->major_version != cpu_to_le32(1) ||
1492 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1493 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1494 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1495 		return -EINVAL;
1496 
1497 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1498 		printk("md: invalid superblock checksum on %s\n",
1499 			bdevname(rdev->bdev,b));
1500 		return -EINVAL;
1501 	}
1502 	if (le64_to_cpu(sb->data_size) < 10) {
1503 		printk("md: data_size too small on %s\n",
1504 		       bdevname(rdev->bdev,b));
1505 		return -EINVAL;
1506 	}
1507 	if (sb->pad0 ||
1508 	    sb->pad3[0] ||
1509 	    memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1510 		/* Some padding is non-zero, might be a new feature */
1511 		return -EINVAL;
1512 
1513 	rdev->preferred_minor = 0xffff;
1514 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1515 	rdev->new_data_offset = rdev->data_offset;
1516 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1517 	    (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1518 		rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1519 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1520 
1521 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1522 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1523 	if (rdev->sb_size & bmask)
1524 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1525 
1526 	if (minor_version
1527 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1528 		return -EINVAL;
1529 	if (minor_version
1530 	    && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1531 		return -EINVAL;
1532 
1533 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1534 		rdev->desc_nr = -1;
1535 	else
1536 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1537 
1538 	if (!rdev->bb_page) {
1539 		rdev->bb_page = alloc_page(GFP_KERNEL);
1540 		if (!rdev->bb_page)
1541 			return -ENOMEM;
1542 	}
1543 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1544 	    rdev->badblocks.count == 0) {
1545 		/* need to load the bad block list.
1546 		 * Currently we limit it to one page.
1547 		 */
1548 		s32 offset;
1549 		sector_t bb_sector;
1550 		u64 *bbp;
1551 		int i;
1552 		int sectors = le16_to_cpu(sb->bblog_size);
1553 		if (sectors > (PAGE_SIZE / 512))
1554 			return -EINVAL;
1555 		offset = le32_to_cpu(sb->bblog_offset);
1556 		if (offset == 0)
1557 			return -EINVAL;
1558 		bb_sector = (long long)offset;
1559 		if (!sync_page_io(rdev, bb_sector, sectors << 9,
1560 				  rdev->bb_page, READ, true))
1561 			return -EIO;
1562 		bbp = (u64 *)page_address(rdev->bb_page);
1563 		rdev->badblocks.shift = sb->bblog_shift;
1564 		for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1565 			u64 bb = le64_to_cpu(*bbp);
1566 			int count = bb & (0x3ff);
1567 			u64 sector = bb >> 10;
1568 			sector <<= sb->bblog_shift;
1569 			count <<= sb->bblog_shift;
1570 			if (bb + 1 == 0)
1571 				break;
1572 			if (md_set_badblocks(&rdev->badblocks,
1573 					     sector, count, 1) == 0)
1574 				return -EINVAL;
1575 		}
1576 	} else if (sb->bblog_offset == 0)
1577 		rdev->badblocks.shift = -1;
1578 
1579 	if (!refdev) {
1580 		ret = 1;
1581 	} else {
1582 		__u64 ev1, ev2;
1583 		struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1584 
1585 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1586 		    sb->level != refsb->level ||
1587 		    sb->layout != refsb->layout ||
1588 		    sb->chunksize != refsb->chunksize) {
1589 			printk(KERN_WARNING "md: %s has strangely different"
1590 				" superblock to %s\n",
1591 				bdevname(rdev->bdev,b),
1592 				bdevname(refdev->bdev,b2));
1593 			return -EINVAL;
1594 		}
1595 		ev1 = le64_to_cpu(sb->events);
1596 		ev2 = le64_to_cpu(refsb->events);
1597 
1598 		if (ev1 > ev2)
1599 			ret = 1;
1600 		else
1601 			ret = 0;
1602 	}
1603 	if (minor_version) {
1604 		sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1605 		sectors -= rdev->data_offset;
1606 	} else
1607 		sectors = rdev->sb_start;
1608 	if (sectors < le64_to_cpu(sb->data_size))
1609 		return -EINVAL;
1610 	rdev->sectors = le64_to_cpu(sb->data_size);
1611 	return ret;
1612 }
1613 
1614 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1615 {
1616 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1617 	__u64 ev1 = le64_to_cpu(sb->events);
1618 
1619 	rdev->raid_disk = -1;
1620 	clear_bit(Faulty, &rdev->flags);
1621 	clear_bit(In_sync, &rdev->flags);
1622 	clear_bit(WriteMostly, &rdev->flags);
1623 
1624 	if (mddev->raid_disks == 0) {
1625 		mddev->major_version = 1;
1626 		mddev->patch_version = 0;
1627 		mddev->external = 0;
1628 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1629 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1630 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1631 		mddev->level = le32_to_cpu(sb->level);
1632 		mddev->clevel[0] = 0;
1633 		mddev->layout = le32_to_cpu(sb->layout);
1634 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1635 		mddev->dev_sectors = le64_to_cpu(sb->size);
1636 		mddev->events = ev1;
1637 		mddev->bitmap_info.offset = 0;
1638 		mddev->bitmap_info.space = 0;
1639 		/* Default location for bitmap is 1K after superblock
1640 		 * using 3K - total of 4K
1641 		 */
1642 		mddev->bitmap_info.default_offset = 1024 >> 9;
1643 		mddev->bitmap_info.default_space = (4096-1024) >> 9;
1644 		mddev->reshape_backwards = 0;
1645 
1646 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1647 		memcpy(mddev->uuid, sb->set_uuid, 16);
1648 
1649 		mddev->max_disks =  (4096-256)/2;
1650 
1651 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1652 		    mddev->bitmap_info.file == NULL) {
1653 			mddev->bitmap_info.offset =
1654 				(__s32)le32_to_cpu(sb->bitmap_offset);
1655 			/* Metadata doesn't record how much space is available.
1656 			 * For 1.0, we assume we can use up to the superblock
1657 			 * if before, else to 4K beyond superblock.
1658 			 * For others, assume no change is possible.
1659 			 */
1660 			if (mddev->minor_version > 0)
1661 				mddev->bitmap_info.space = 0;
1662 			else if (mddev->bitmap_info.offset > 0)
1663 				mddev->bitmap_info.space =
1664 					8 - mddev->bitmap_info.offset;
1665 			else
1666 				mddev->bitmap_info.space =
1667 					-mddev->bitmap_info.offset;
1668 		}
1669 
1670 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1671 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1672 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1673 			mddev->new_level = le32_to_cpu(sb->new_level);
1674 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1675 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1676 			if (mddev->delta_disks < 0 ||
1677 			    (mddev->delta_disks == 0 &&
1678 			     (le32_to_cpu(sb->feature_map)
1679 			      & MD_FEATURE_RESHAPE_BACKWARDS)))
1680 				mddev->reshape_backwards = 1;
1681 		} else {
1682 			mddev->reshape_position = MaxSector;
1683 			mddev->delta_disks = 0;
1684 			mddev->new_level = mddev->level;
1685 			mddev->new_layout = mddev->layout;
1686 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1687 		}
1688 
1689 	} else if (mddev->pers == NULL) {
1690 		/* Insist of good event counter while assembling, except for
1691 		 * spares (which don't need an event count) */
1692 		++ev1;
1693 		if (rdev->desc_nr >= 0 &&
1694 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1695 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1696 			if (ev1 < mddev->events)
1697 				return -EINVAL;
1698 	} else if (mddev->bitmap) {
1699 		/* If adding to array with a bitmap, then we can accept an
1700 		 * older device, but not too old.
1701 		 */
1702 		if (ev1 < mddev->bitmap->events_cleared)
1703 			return 0;
1704 	} else {
1705 		if (ev1 < mddev->events)
1706 			/* just a hot-add of a new device, leave raid_disk at -1 */
1707 			return 0;
1708 	}
1709 	if (mddev->level != LEVEL_MULTIPATH) {
1710 		int role;
1711 		if (rdev->desc_nr < 0 ||
1712 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1713 			role = 0xffff;
1714 			rdev->desc_nr = -1;
1715 		} else
1716 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1717 		switch(role) {
1718 		case 0xffff: /* spare */
1719 			break;
1720 		case 0xfffe: /* faulty */
1721 			set_bit(Faulty, &rdev->flags);
1722 			break;
1723 		default:
1724 			if ((le32_to_cpu(sb->feature_map) &
1725 			     MD_FEATURE_RECOVERY_OFFSET))
1726 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1727 			else
1728 				set_bit(In_sync, &rdev->flags);
1729 			rdev->raid_disk = role;
1730 			break;
1731 		}
1732 		if (sb->devflags & WriteMostly1)
1733 			set_bit(WriteMostly, &rdev->flags);
1734 		if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1735 			set_bit(Replacement, &rdev->flags);
1736 	} else /* MULTIPATH are always insync */
1737 		set_bit(In_sync, &rdev->flags);
1738 
1739 	return 0;
1740 }
1741 
1742 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1743 {
1744 	struct mdp_superblock_1 *sb;
1745 	struct md_rdev *rdev2;
1746 	int max_dev, i;
1747 	/* make rdev->sb match mddev and rdev data. */
1748 
1749 	sb = page_address(rdev->sb_page);
1750 
1751 	sb->feature_map = 0;
1752 	sb->pad0 = 0;
1753 	sb->recovery_offset = cpu_to_le64(0);
1754 	memset(sb->pad3, 0, sizeof(sb->pad3));
1755 
1756 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1757 	sb->events = cpu_to_le64(mddev->events);
1758 	if (mddev->in_sync)
1759 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1760 	else
1761 		sb->resync_offset = cpu_to_le64(0);
1762 
1763 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1764 
1765 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1766 	sb->size = cpu_to_le64(mddev->dev_sectors);
1767 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1768 	sb->level = cpu_to_le32(mddev->level);
1769 	sb->layout = cpu_to_le32(mddev->layout);
1770 
1771 	if (test_bit(WriteMostly, &rdev->flags))
1772 		sb->devflags |= WriteMostly1;
1773 	else
1774 		sb->devflags &= ~WriteMostly1;
1775 	sb->data_offset = cpu_to_le64(rdev->data_offset);
1776 	sb->data_size = cpu_to_le64(rdev->sectors);
1777 
1778 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1779 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1780 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1781 	}
1782 
1783 	if (rdev->raid_disk >= 0 &&
1784 	    !test_bit(In_sync, &rdev->flags)) {
1785 		sb->feature_map |=
1786 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1787 		sb->recovery_offset =
1788 			cpu_to_le64(rdev->recovery_offset);
1789 	}
1790 	if (test_bit(Replacement, &rdev->flags))
1791 		sb->feature_map |=
1792 			cpu_to_le32(MD_FEATURE_REPLACEMENT);
1793 
1794 	if (mddev->reshape_position != MaxSector) {
1795 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1796 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1797 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1798 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1799 		sb->new_level = cpu_to_le32(mddev->new_level);
1800 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1801 		if (mddev->delta_disks == 0 &&
1802 		    mddev->reshape_backwards)
1803 			sb->feature_map
1804 				|= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1805 		if (rdev->new_data_offset != rdev->data_offset) {
1806 			sb->feature_map
1807 				|= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1808 			sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1809 							     - rdev->data_offset));
1810 		}
1811 	}
1812 
1813 	if (rdev->badblocks.count == 0)
1814 		/* Nothing to do for bad blocks*/ ;
1815 	else if (sb->bblog_offset == 0)
1816 		/* Cannot record bad blocks on this device */
1817 		md_error(mddev, rdev);
1818 	else {
1819 		struct badblocks *bb = &rdev->badblocks;
1820 		u64 *bbp = (u64 *)page_address(rdev->bb_page);
1821 		u64 *p = bb->page;
1822 		sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1823 		if (bb->changed) {
1824 			unsigned seq;
1825 
1826 retry:
1827 			seq = read_seqbegin(&bb->lock);
1828 
1829 			memset(bbp, 0xff, PAGE_SIZE);
1830 
1831 			for (i = 0 ; i < bb->count ; i++) {
1832 				u64 internal_bb = *p++;
1833 				u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1834 						| BB_LEN(internal_bb));
1835 				*bbp++ = cpu_to_le64(store_bb);
1836 			}
1837 			bb->changed = 0;
1838 			if (read_seqretry(&bb->lock, seq))
1839 				goto retry;
1840 
1841 			bb->sector = (rdev->sb_start +
1842 				      (int)le32_to_cpu(sb->bblog_offset));
1843 			bb->size = le16_to_cpu(sb->bblog_size);
1844 		}
1845 	}
1846 
1847 	max_dev = 0;
1848 	rdev_for_each(rdev2, mddev)
1849 		if (rdev2->desc_nr+1 > max_dev)
1850 			max_dev = rdev2->desc_nr+1;
1851 
1852 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1853 		int bmask;
1854 		sb->max_dev = cpu_to_le32(max_dev);
1855 		rdev->sb_size = max_dev * 2 + 256;
1856 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1857 		if (rdev->sb_size & bmask)
1858 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1859 	} else
1860 		max_dev = le32_to_cpu(sb->max_dev);
1861 
1862 	for (i=0; i<max_dev;i++)
1863 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1864 
1865 	rdev_for_each(rdev2, mddev) {
1866 		i = rdev2->desc_nr;
1867 		if (test_bit(Faulty, &rdev2->flags))
1868 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1869 		else if (test_bit(In_sync, &rdev2->flags))
1870 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1871 		else if (rdev2->raid_disk >= 0)
1872 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1873 		else
1874 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1875 	}
1876 
1877 	sb->sb_csum = calc_sb_1_csum(sb);
1878 }
1879 
1880 static unsigned long long
1881 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1882 {
1883 	struct mdp_superblock_1 *sb;
1884 	sector_t max_sectors;
1885 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1886 		return 0; /* component must fit device */
1887 	if (rdev->data_offset != rdev->new_data_offset)
1888 		return 0; /* too confusing */
1889 	if (rdev->sb_start < rdev->data_offset) {
1890 		/* minor versions 1 and 2; superblock before data */
1891 		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1892 		max_sectors -= rdev->data_offset;
1893 		if (!num_sectors || num_sectors > max_sectors)
1894 			num_sectors = max_sectors;
1895 	} else if (rdev->mddev->bitmap_info.offset) {
1896 		/* minor version 0 with bitmap we can't move */
1897 		return 0;
1898 	} else {
1899 		/* minor version 0; superblock after data */
1900 		sector_t sb_start;
1901 		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1902 		sb_start &= ~(sector_t)(4*2 - 1);
1903 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1904 		if (!num_sectors || num_sectors > max_sectors)
1905 			num_sectors = max_sectors;
1906 		rdev->sb_start = sb_start;
1907 	}
1908 	sb = page_address(rdev->sb_page);
1909 	sb->data_size = cpu_to_le64(num_sectors);
1910 	sb->super_offset = rdev->sb_start;
1911 	sb->sb_csum = calc_sb_1_csum(sb);
1912 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1913 		       rdev->sb_page);
1914 	md_super_wait(rdev->mddev);
1915 	return num_sectors;
1916 
1917 }
1918 
1919 static int
1920 super_1_allow_new_offset(struct md_rdev *rdev,
1921 			 unsigned long long new_offset)
1922 {
1923 	/* All necessary checks on new >= old have been done */
1924 	struct bitmap *bitmap;
1925 	if (new_offset >= rdev->data_offset)
1926 		return 1;
1927 
1928 	/* with 1.0 metadata, there is no metadata to tread on
1929 	 * so we can always move back */
1930 	if (rdev->mddev->minor_version == 0)
1931 		return 1;
1932 
1933 	/* otherwise we must be sure not to step on
1934 	 * any metadata, so stay:
1935 	 * 36K beyond start of superblock
1936 	 * beyond end of badblocks
1937 	 * beyond write-intent bitmap
1938 	 */
1939 	if (rdev->sb_start + (32+4)*2 > new_offset)
1940 		return 0;
1941 	bitmap = rdev->mddev->bitmap;
1942 	if (bitmap && !rdev->mddev->bitmap_info.file &&
1943 	    rdev->sb_start + rdev->mddev->bitmap_info.offset +
1944 	    bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1945 		return 0;
1946 	if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1947 		return 0;
1948 
1949 	return 1;
1950 }
1951 
1952 static struct super_type super_types[] = {
1953 	[0] = {
1954 		.name	= "0.90.0",
1955 		.owner	= THIS_MODULE,
1956 		.load_super	    = super_90_load,
1957 		.validate_super	    = super_90_validate,
1958 		.sync_super	    = super_90_sync,
1959 		.rdev_size_change   = super_90_rdev_size_change,
1960 		.allow_new_offset   = super_90_allow_new_offset,
1961 	},
1962 	[1] = {
1963 		.name	= "md-1",
1964 		.owner	= THIS_MODULE,
1965 		.load_super	    = super_1_load,
1966 		.validate_super	    = super_1_validate,
1967 		.sync_super	    = super_1_sync,
1968 		.rdev_size_change   = super_1_rdev_size_change,
1969 		.allow_new_offset   = super_1_allow_new_offset,
1970 	},
1971 };
1972 
1973 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1974 {
1975 	if (mddev->sync_super) {
1976 		mddev->sync_super(mddev, rdev);
1977 		return;
1978 	}
1979 
1980 	BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1981 
1982 	super_types[mddev->major_version].sync_super(mddev, rdev);
1983 }
1984 
1985 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1986 {
1987 	struct md_rdev *rdev, *rdev2;
1988 
1989 	rcu_read_lock();
1990 	rdev_for_each_rcu(rdev, mddev1)
1991 		rdev_for_each_rcu(rdev2, mddev2)
1992 			if (rdev->bdev->bd_contains ==
1993 			    rdev2->bdev->bd_contains) {
1994 				rcu_read_unlock();
1995 				return 1;
1996 			}
1997 	rcu_read_unlock();
1998 	return 0;
1999 }
2000 
2001 static LIST_HEAD(pending_raid_disks);
2002 
2003 /*
2004  * Try to register data integrity profile for an mddev
2005  *
2006  * This is called when an array is started and after a disk has been kicked
2007  * from the array. It only succeeds if all working and active component devices
2008  * are integrity capable with matching profiles.
2009  */
2010 int md_integrity_register(struct mddev *mddev)
2011 {
2012 	struct md_rdev *rdev, *reference = NULL;
2013 
2014 	if (list_empty(&mddev->disks))
2015 		return 0; /* nothing to do */
2016 	if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
2017 		return 0; /* shouldn't register, or already is */
2018 	rdev_for_each(rdev, mddev) {
2019 		/* skip spares and non-functional disks */
2020 		if (test_bit(Faulty, &rdev->flags))
2021 			continue;
2022 		if (rdev->raid_disk < 0)
2023 			continue;
2024 		if (!reference) {
2025 			/* Use the first rdev as the reference */
2026 			reference = rdev;
2027 			continue;
2028 		}
2029 		/* does this rdev's profile match the reference profile? */
2030 		if (blk_integrity_compare(reference->bdev->bd_disk,
2031 				rdev->bdev->bd_disk) < 0)
2032 			return -EINVAL;
2033 	}
2034 	if (!reference || !bdev_get_integrity(reference->bdev))
2035 		return 0;
2036 	/*
2037 	 * All component devices are integrity capable and have matching
2038 	 * profiles, register the common profile for the md device.
2039 	 */
2040 	if (blk_integrity_register(mddev->gendisk,
2041 			bdev_get_integrity(reference->bdev)) != 0) {
2042 		printk(KERN_ERR "md: failed to register integrity for %s\n",
2043 			mdname(mddev));
2044 		return -EINVAL;
2045 	}
2046 	printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2047 	if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2048 		printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2049 		       mdname(mddev));
2050 		return -EINVAL;
2051 	}
2052 	return 0;
2053 }
2054 EXPORT_SYMBOL(md_integrity_register);
2055 
2056 /* Disable data integrity if non-capable/non-matching disk is being added */
2057 void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2058 {
2059 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
2060 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
2061 
2062 	if (!bi_mddev) /* nothing to do */
2063 		return;
2064 	if (rdev->raid_disk < 0) /* skip spares */
2065 		return;
2066 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
2067 					     rdev->bdev->bd_disk) >= 0)
2068 		return;
2069 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
2070 	blk_integrity_unregister(mddev->gendisk);
2071 }
2072 EXPORT_SYMBOL(md_integrity_add_rdev);
2073 
2074 static int bind_rdev_to_array(struct md_rdev * rdev, struct mddev * mddev)
2075 {
2076 	char b[BDEVNAME_SIZE];
2077 	struct kobject *ko;
2078 	char *s;
2079 	int err;
2080 
2081 	if (rdev->mddev) {
2082 		MD_BUG();
2083 		return -EINVAL;
2084 	}
2085 
2086 	/* prevent duplicates */
2087 	if (find_rdev(mddev, rdev->bdev->bd_dev))
2088 		return -EEXIST;
2089 
2090 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
2091 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
2092 			rdev->sectors < mddev->dev_sectors)) {
2093 		if (mddev->pers) {
2094 			/* Cannot change size, so fail
2095 			 * If mddev->level <= 0, then we don't care
2096 			 * about aligning sizes (e.g. linear)
2097 			 */
2098 			if (mddev->level > 0)
2099 				return -ENOSPC;
2100 		} else
2101 			mddev->dev_sectors = rdev->sectors;
2102 	}
2103 
2104 	/* Verify rdev->desc_nr is unique.
2105 	 * If it is -1, assign a free number, else
2106 	 * check number is not in use
2107 	 */
2108 	if (rdev->desc_nr < 0) {
2109 		int choice = 0;
2110 		if (mddev->pers) choice = mddev->raid_disks;
2111 		while (find_rdev_nr(mddev, choice))
2112 			choice++;
2113 		rdev->desc_nr = choice;
2114 	} else {
2115 		if (find_rdev_nr(mddev, rdev->desc_nr))
2116 			return -EBUSY;
2117 	}
2118 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2119 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2120 		       mdname(mddev), mddev->max_disks);
2121 		return -EBUSY;
2122 	}
2123 	bdevname(rdev->bdev,b);
2124 	while ( (s=strchr(b, '/')) != NULL)
2125 		*s = '!';
2126 
2127 	rdev->mddev = mddev;
2128 	printk(KERN_INFO "md: bind<%s>\n", b);
2129 
2130 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2131 		goto fail;
2132 
2133 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2134 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
2135 		/* failure here is OK */;
2136 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2137 
2138 	list_add_rcu(&rdev->same_set, &mddev->disks);
2139 	bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2140 
2141 	/* May as well allow recovery to be retried once */
2142 	mddev->recovery_disabled++;
2143 
2144 	return 0;
2145 
2146  fail:
2147 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2148 	       b, mdname(mddev));
2149 	return err;
2150 }
2151 
2152 static void md_delayed_delete(struct work_struct *ws)
2153 {
2154 	struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2155 	kobject_del(&rdev->kobj);
2156 	kobject_put(&rdev->kobj);
2157 }
2158 
2159 static void unbind_rdev_from_array(struct md_rdev * rdev)
2160 {
2161 	char b[BDEVNAME_SIZE];
2162 	if (!rdev->mddev) {
2163 		MD_BUG();
2164 		return;
2165 	}
2166 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2167 	list_del_rcu(&rdev->same_set);
2168 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2169 	rdev->mddev = NULL;
2170 	sysfs_remove_link(&rdev->kobj, "block");
2171 	sysfs_put(rdev->sysfs_state);
2172 	rdev->sysfs_state = NULL;
2173 	rdev->badblocks.count = 0;
2174 	/* We need to delay this, otherwise we can deadlock when
2175 	 * writing to 'remove' to "dev/state".  We also need
2176 	 * to delay it due to rcu usage.
2177 	 */
2178 	synchronize_rcu();
2179 	INIT_WORK(&rdev->del_work, md_delayed_delete);
2180 	kobject_get(&rdev->kobj);
2181 	queue_work(md_misc_wq, &rdev->del_work);
2182 }
2183 
2184 /*
2185  * prevent the device from being mounted, repartitioned or
2186  * otherwise reused by a RAID array (or any other kernel
2187  * subsystem), by bd_claiming the device.
2188  */
2189 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2190 {
2191 	int err = 0;
2192 	struct block_device *bdev;
2193 	char b[BDEVNAME_SIZE];
2194 
2195 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2196 				 shared ? (struct md_rdev *)lock_rdev : rdev);
2197 	if (IS_ERR(bdev)) {
2198 		printk(KERN_ERR "md: could not open %s.\n",
2199 			__bdevname(dev, b));
2200 		return PTR_ERR(bdev);
2201 	}
2202 	rdev->bdev = bdev;
2203 	return err;
2204 }
2205 
2206 static void unlock_rdev(struct md_rdev *rdev)
2207 {
2208 	struct block_device *bdev = rdev->bdev;
2209 	rdev->bdev = NULL;
2210 	if (!bdev)
2211 		MD_BUG();
2212 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2213 }
2214 
2215 void md_autodetect_dev(dev_t dev);
2216 
2217 static void export_rdev(struct md_rdev * rdev)
2218 {
2219 	char b[BDEVNAME_SIZE];
2220 	printk(KERN_INFO "md: export_rdev(%s)\n",
2221 		bdevname(rdev->bdev,b));
2222 	if (rdev->mddev)
2223 		MD_BUG();
2224 	md_rdev_clear(rdev);
2225 #ifndef MODULE
2226 	if (test_bit(AutoDetected, &rdev->flags))
2227 		md_autodetect_dev(rdev->bdev->bd_dev);
2228 #endif
2229 	unlock_rdev(rdev);
2230 	kobject_put(&rdev->kobj);
2231 }
2232 
2233 static void kick_rdev_from_array(struct md_rdev * rdev)
2234 {
2235 	unbind_rdev_from_array(rdev);
2236 	export_rdev(rdev);
2237 }
2238 
2239 static void export_array(struct mddev *mddev)
2240 {
2241 	struct md_rdev *rdev, *tmp;
2242 
2243 	rdev_for_each_safe(rdev, tmp, mddev) {
2244 		if (!rdev->mddev) {
2245 			MD_BUG();
2246 			continue;
2247 		}
2248 		kick_rdev_from_array(rdev);
2249 	}
2250 	if (!list_empty(&mddev->disks))
2251 		MD_BUG();
2252 	mddev->raid_disks = 0;
2253 	mddev->major_version = 0;
2254 }
2255 
2256 static void print_desc(mdp_disk_t *desc)
2257 {
2258 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2259 		desc->major,desc->minor,desc->raid_disk,desc->state);
2260 }
2261 
2262 static void print_sb_90(mdp_super_t *sb)
2263 {
2264 	int i;
2265 
2266 	printk(KERN_INFO
2267 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2268 		sb->major_version, sb->minor_version, sb->patch_version,
2269 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2270 		sb->ctime);
2271 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2272 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2273 		sb->md_minor, sb->layout, sb->chunk_size);
2274 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2275 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2276 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2277 		sb->failed_disks, sb->spare_disks,
2278 		sb->sb_csum, (unsigned long)sb->events_lo);
2279 
2280 	printk(KERN_INFO);
2281 	for (i = 0; i < MD_SB_DISKS; i++) {
2282 		mdp_disk_t *desc;
2283 
2284 		desc = sb->disks + i;
2285 		if (desc->number || desc->major || desc->minor ||
2286 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2287 			printk("     D %2d: ", i);
2288 			print_desc(desc);
2289 		}
2290 	}
2291 	printk(KERN_INFO "md:     THIS: ");
2292 	print_desc(&sb->this_disk);
2293 }
2294 
2295 static void print_sb_1(struct mdp_superblock_1 *sb)
2296 {
2297 	__u8 *uuid;
2298 
2299 	uuid = sb->set_uuid;
2300 	printk(KERN_INFO
2301 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2302 	       "md:    Name: \"%s\" CT:%llu\n",
2303 		le32_to_cpu(sb->major_version),
2304 		le32_to_cpu(sb->feature_map),
2305 		uuid,
2306 		sb->set_name,
2307 		(unsigned long long)le64_to_cpu(sb->ctime)
2308 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2309 
2310 	uuid = sb->device_uuid;
2311 	printk(KERN_INFO
2312 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2313 			" RO:%llu\n"
2314 	       "md:     Dev:%08x UUID: %pU\n"
2315 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2316 	       "md:         (MaxDev:%u) \n",
2317 		le32_to_cpu(sb->level),
2318 		(unsigned long long)le64_to_cpu(sb->size),
2319 		le32_to_cpu(sb->raid_disks),
2320 		le32_to_cpu(sb->layout),
2321 		le32_to_cpu(sb->chunksize),
2322 		(unsigned long long)le64_to_cpu(sb->data_offset),
2323 		(unsigned long long)le64_to_cpu(sb->data_size),
2324 		(unsigned long long)le64_to_cpu(sb->super_offset),
2325 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2326 		le32_to_cpu(sb->dev_number),
2327 		uuid,
2328 		sb->devflags,
2329 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2330 		(unsigned long long)le64_to_cpu(sb->events),
2331 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2332 		le32_to_cpu(sb->sb_csum),
2333 		le32_to_cpu(sb->max_dev)
2334 		);
2335 }
2336 
2337 static void print_rdev(struct md_rdev *rdev, int major_version)
2338 {
2339 	char b[BDEVNAME_SIZE];
2340 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2341 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2342 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2343 	        rdev->desc_nr);
2344 	if (rdev->sb_loaded) {
2345 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2346 		switch (major_version) {
2347 		case 0:
2348 			print_sb_90(page_address(rdev->sb_page));
2349 			break;
2350 		case 1:
2351 			print_sb_1(page_address(rdev->sb_page));
2352 			break;
2353 		}
2354 	} else
2355 		printk(KERN_INFO "md: no rdev superblock!\n");
2356 }
2357 
2358 static void md_print_devices(void)
2359 {
2360 	struct list_head *tmp;
2361 	struct md_rdev *rdev;
2362 	struct mddev *mddev;
2363 	char b[BDEVNAME_SIZE];
2364 
2365 	printk("\n");
2366 	printk("md:	**********************************\n");
2367 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2368 	printk("md:	**********************************\n");
2369 	for_each_mddev(mddev, tmp) {
2370 
2371 		if (mddev->bitmap)
2372 			bitmap_print_sb(mddev->bitmap);
2373 		else
2374 			printk("%s: ", mdname(mddev));
2375 		rdev_for_each(rdev, mddev)
2376 			printk("<%s>", bdevname(rdev->bdev,b));
2377 		printk("\n");
2378 
2379 		rdev_for_each(rdev, mddev)
2380 			print_rdev(rdev, mddev->major_version);
2381 	}
2382 	printk("md:	**********************************\n");
2383 	printk("\n");
2384 }
2385 
2386 
2387 static void sync_sbs(struct mddev * mddev, int nospares)
2388 {
2389 	/* Update each superblock (in-memory image), but
2390 	 * if we are allowed to, skip spares which already
2391 	 * have the right event counter, or have one earlier
2392 	 * (which would mean they aren't being marked as dirty
2393 	 * with the rest of the array)
2394 	 */
2395 	struct md_rdev *rdev;
2396 	rdev_for_each(rdev, mddev) {
2397 		if (rdev->sb_events == mddev->events ||
2398 		    (nospares &&
2399 		     rdev->raid_disk < 0 &&
2400 		     rdev->sb_events+1 == mddev->events)) {
2401 			/* Don't update this superblock */
2402 			rdev->sb_loaded = 2;
2403 		} else {
2404 			sync_super(mddev, rdev);
2405 			rdev->sb_loaded = 1;
2406 		}
2407 	}
2408 }
2409 
2410 static void md_update_sb(struct mddev * mddev, int force_change)
2411 {
2412 	struct md_rdev *rdev;
2413 	int sync_req;
2414 	int nospares = 0;
2415 	int any_badblocks_changed = 0;
2416 
2417 repeat:
2418 	/* First make sure individual recovery_offsets are correct */
2419 	rdev_for_each(rdev, mddev) {
2420 		if (rdev->raid_disk >= 0 &&
2421 		    mddev->delta_disks >= 0 &&
2422 		    !test_bit(In_sync, &rdev->flags) &&
2423 		    mddev->curr_resync_completed > rdev->recovery_offset)
2424 				rdev->recovery_offset = mddev->curr_resync_completed;
2425 
2426 	}
2427 	if (!mddev->persistent) {
2428 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2429 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2430 		if (!mddev->external) {
2431 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2432 			rdev_for_each(rdev, mddev) {
2433 				if (rdev->badblocks.changed) {
2434 					rdev->badblocks.changed = 0;
2435 					md_ack_all_badblocks(&rdev->badblocks);
2436 					md_error(mddev, rdev);
2437 				}
2438 				clear_bit(Blocked, &rdev->flags);
2439 				clear_bit(BlockedBadBlocks, &rdev->flags);
2440 				wake_up(&rdev->blocked_wait);
2441 			}
2442 		}
2443 		wake_up(&mddev->sb_wait);
2444 		return;
2445 	}
2446 
2447 	spin_lock_irq(&mddev->write_lock);
2448 
2449 	mddev->utime = get_seconds();
2450 
2451 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2452 		force_change = 1;
2453 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2454 		/* just a clean<-> dirty transition, possibly leave spares alone,
2455 		 * though if events isn't the right even/odd, we will have to do
2456 		 * spares after all
2457 		 */
2458 		nospares = 1;
2459 	if (force_change)
2460 		nospares = 0;
2461 	if (mddev->degraded)
2462 		/* If the array is degraded, then skipping spares is both
2463 		 * dangerous and fairly pointless.
2464 		 * Dangerous because a device that was removed from the array
2465 		 * might have a event_count that still looks up-to-date,
2466 		 * so it can be re-added without a resync.
2467 		 * Pointless because if there are any spares to skip,
2468 		 * then a recovery will happen and soon that array won't
2469 		 * be degraded any more and the spare can go back to sleep then.
2470 		 */
2471 		nospares = 0;
2472 
2473 	sync_req = mddev->in_sync;
2474 
2475 	/* If this is just a dirty<->clean transition, and the array is clean
2476 	 * and 'events' is odd, we can roll back to the previous clean state */
2477 	if (nospares
2478 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2479 	    && mddev->can_decrease_events
2480 	    && mddev->events != 1) {
2481 		mddev->events--;
2482 		mddev->can_decrease_events = 0;
2483 	} else {
2484 		/* otherwise we have to go forward and ... */
2485 		mddev->events ++;
2486 		mddev->can_decrease_events = nospares;
2487 	}
2488 
2489 	if (!mddev->events) {
2490 		/*
2491 		 * oops, this 64-bit counter should never wrap.
2492 		 * Either we are in around ~1 trillion A.C., assuming
2493 		 * 1 reboot per second, or we have a bug:
2494 		 */
2495 		MD_BUG();
2496 		mddev->events --;
2497 	}
2498 
2499 	rdev_for_each(rdev, mddev) {
2500 		if (rdev->badblocks.changed)
2501 			any_badblocks_changed++;
2502 		if (test_bit(Faulty, &rdev->flags))
2503 			set_bit(FaultRecorded, &rdev->flags);
2504 	}
2505 
2506 	sync_sbs(mddev, nospares);
2507 	spin_unlock_irq(&mddev->write_lock);
2508 
2509 	pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2510 		 mdname(mddev), mddev->in_sync);
2511 
2512 	bitmap_update_sb(mddev->bitmap);
2513 	rdev_for_each(rdev, mddev) {
2514 		char b[BDEVNAME_SIZE];
2515 
2516 		if (rdev->sb_loaded != 1)
2517 			continue; /* no noise on spare devices */
2518 
2519 		if (!test_bit(Faulty, &rdev->flags) &&
2520 		    rdev->saved_raid_disk == -1) {
2521 			md_super_write(mddev,rdev,
2522 				       rdev->sb_start, rdev->sb_size,
2523 				       rdev->sb_page);
2524 			pr_debug("md: (write) %s's sb offset: %llu\n",
2525 				 bdevname(rdev->bdev, b),
2526 				 (unsigned long long)rdev->sb_start);
2527 			rdev->sb_events = mddev->events;
2528 			if (rdev->badblocks.size) {
2529 				md_super_write(mddev, rdev,
2530 					       rdev->badblocks.sector,
2531 					       rdev->badblocks.size << 9,
2532 					       rdev->bb_page);
2533 				rdev->badblocks.size = 0;
2534 			}
2535 
2536 		} else if (test_bit(Faulty, &rdev->flags))
2537 			pr_debug("md: %s (skipping faulty)\n",
2538 				 bdevname(rdev->bdev, b));
2539 		else
2540 			pr_debug("(skipping incremental s/r ");
2541 
2542 		if (mddev->level == LEVEL_MULTIPATH)
2543 			/* only need to write one superblock... */
2544 			break;
2545 	}
2546 	md_super_wait(mddev);
2547 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2548 
2549 	spin_lock_irq(&mddev->write_lock);
2550 	if (mddev->in_sync != sync_req ||
2551 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2552 		/* have to write it out again */
2553 		spin_unlock_irq(&mddev->write_lock);
2554 		goto repeat;
2555 	}
2556 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2557 	spin_unlock_irq(&mddev->write_lock);
2558 	wake_up(&mddev->sb_wait);
2559 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2560 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2561 
2562 	rdev_for_each(rdev, mddev) {
2563 		if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2564 			clear_bit(Blocked, &rdev->flags);
2565 
2566 		if (any_badblocks_changed)
2567 			md_ack_all_badblocks(&rdev->badblocks);
2568 		clear_bit(BlockedBadBlocks, &rdev->flags);
2569 		wake_up(&rdev->blocked_wait);
2570 	}
2571 }
2572 
2573 /* words written to sysfs files may, or may not, be \n terminated.
2574  * We want to accept with case. For this we use cmd_match.
2575  */
2576 static int cmd_match(const char *cmd, const char *str)
2577 {
2578 	/* See if cmd, written into a sysfs file, matches
2579 	 * str.  They must either be the same, or cmd can
2580 	 * have a trailing newline
2581 	 */
2582 	while (*cmd && *str && *cmd == *str) {
2583 		cmd++;
2584 		str++;
2585 	}
2586 	if (*cmd == '\n')
2587 		cmd++;
2588 	if (*str || *cmd)
2589 		return 0;
2590 	return 1;
2591 }
2592 
2593 struct rdev_sysfs_entry {
2594 	struct attribute attr;
2595 	ssize_t (*show)(struct md_rdev *, char *);
2596 	ssize_t (*store)(struct md_rdev *, const char *, size_t);
2597 };
2598 
2599 static ssize_t
2600 state_show(struct md_rdev *rdev, char *page)
2601 {
2602 	char *sep = "";
2603 	size_t len = 0;
2604 
2605 	if (test_bit(Faulty, &rdev->flags) ||
2606 	    rdev->badblocks.unacked_exist) {
2607 		len+= sprintf(page+len, "%sfaulty",sep);
2608 		sep = ",";
2609 	}
2610 	if (test_bit(In_sync, &rdev->flags)) {
2611 		len += sprintf(page+len, "%sin_sync",sep);
2612 		sep = ",";
2613 	}
2614 	if (test_bit(WriteMostly, &rdev->flags)) {
2615 		len += sprintf(page+len, "%swrite_mostly",sep);
2616 		sep = ",";
2617 	}
2618 	if (test_bit(Blocked, &rdev->flags) ||
2619 	    (rdev->badblocks.unacked_exist
2620 	     && !test_bit(Faulty, &rdev->flags))) {
2621 		len += sprintf(page+len, "%sblocked", sep);
2622 		sep = ",";
2623 	}
2624 	if (!test_bit(Faulty, &rdev->flags) &&
2625 	    !test_bit(In_sync, &rdev->flags)) {
2626 		len += sprintf(page+len, "%sspare", sep);
2627 		sep = ",";
2628 	}
2629 	if (test_bit(WriteErrorSeen, &rdev->flags)) {
2630 		len += sprintf(page+len, "%swrite_error", sep);
2631 		sep = ",";
2632 	}
2633 	if (test_bit(WantReplacement, &rdev->flags)) {
2634 		len += sprintf(page+len, "%swant_replacement", sep);
2635 		sep = ",";
2636 	}
2637 	if (test_bit(Replacement, &rdev->flags)) {
2638 		len += sprintf(page+len, "%sreplacement", sep);
2639 		sep = ",";
2640 	}
2641 
2642 	return len+sprintf(page+len, "\n");
2643 }
2644 
2645 static ssize_t
2646 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2647 {
2648 	/* can write
2649 	 *  faulty  - simulates an error
2650 	 *  remove  - disconnects the device
2651 	 *  writemostly - sets write_mostly
2652 	 *  -writemostly - clears write_mostly
2653 	 *  blocked - sets the Blocked flags
2654 	 *  -blocked - clears the Blocked and possibly simulates an error
2655 	 *  insync - sets Insync providing device isn't active
2656 	 *  write_error - sets WriteErrorSeen
2657 	 *  -write_error - clears WriteErrorSeen
2658 	 */
2659 	int err = -EINVAL;
2660 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2661 		md_error(rdev->mddev, rdev);
2662 		if (test_bit(Faulty, &rdev->flags))
2663 			err = 0;
2664 		else
2665 			err = -EBUSY;
2666 	} else if (cmd_match(buf, "remove")) {
2667 		if (rdev->raid_disk >= 0)
2668 			err = -EBUSY;
2669 		else {
2670 			struct mddev *mddev = rdev->mddev;
2671 			kick_rdev_from_array(rdev);
2672 			if (mddev->pers)
2673 				md_update_sb(mddev, 1);
2674 			md_new_event(mddev);
2675 			err = 0;
2676 		}
2677 	} else if (cmd_match(buf, "writemostly")) {
2678 		set_bit(WriteMostly, &rdev->flags);
2679 		err = 0;
2680 	} else if (cmd_match(buf, "-writemostly")) {
2681 		clear_bit(WriteMostly, &rdev->flags);
2682 		err = 0;
2683 	} else if (cmd_match(buf, "blocked")) {
2684 		set_bit(Blocked, &rdev->flags);
2685 		err = 0;
2686 	} else if (cmd_match(buf, "-blocked")) {
2687 		if (!test_bit(Faulty, &rdev->flags) &&
2688 		    rdev->badblocks.unacked_exist) {
2689 			/* metadata handler doesn't understand badblocks,
2690 			 * so we need to fail the device
2691 			 */
2692 			md_error(rdev->mddev, rdev);
2693 		}
2694 		clear_bit(Blocked, &rdev->flags);
2695 		clear_bit(BlockedBadBlocks, &rdev->flags);
2696 		wake_up(&rdev->blocked_wait);
2697 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2698 		md_wakeup_thread(rdev->mddev->thread);
2699 
2700 		err = 0;
2701 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2702 		set_bit(In_sync, &rdev->flags);
2703 		err = 0;
2704 	} else if (cmd_match(buf, "write_error")) {
2705 		set_bit(WriteErrorSeen, &rdev->flags);
2706 		err = 0;
2707 	} else if (cmd_match(buf, "-write_error")) {
2708 		clear_bit(WriteErrorSeen, &rdev->flags);
2709 		err = 0;
2710 	} else if (cmd_match(buf, "want_replacement")) {
2711 		/* Any non-spare device that is not a replacement can
2712 		 * become want_replacement at any time, but we then need to
2713 		 * check if recovery is needed.
2714 		 */
2715 		if (rdev->raid_disk >= 0 &&
2716 		    !test_bit(Replacement, &rdev->flags))
2717 			set_bit(WantReplacement, &rdev->flags);
2718 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2719 		md_wakeup_thread(rdev->mddev->thread);
2720 		err = 0;
2721 	} else if (cmd_match(buf, "-want_replacement")) {
2722 		/* Clearing 'want_replacement' is always allowed.
2723 		 * Once replacements starts it is too late though.
2724 		 */
2725 		err = 0;
2726 		clear_bit(WantReplacement, &rdev->flags);
2727 	} else if (cmd_match(buf, "replacement")) {
2728 		/* Can only set a device as a replacement when array has not
2729 		 * yet been started.  Once running, replacement is automatic
2730 		 * from spares, or by assigning 'slot'.
2731 		 */
2732 		if (rdev->mddev->pers)
2733 			err = -EBUSY;
2734 		else {
2735 			set_bit(Replacement, &rdev->flags);
2736 			err = 0;
2737 		}
2738 	} else if (cmd_match(buf, "-replacement")) {
2739 		/* Similarly, can only clear Replacement before start */
2740 		if (rdev->mddev->pers)
2741 			err = -EBUSY;
2742 		else {
2743 			clear_bit(Replacement, &rdev->flags);
2744 			err = 0;
2745 		}
2746 	}
2747 	if (!err)
2748 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2749 	return err ? err : len;
2750 }
2751 static struct rdev_sysfs_entry rdev_state =
2752 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2753 
2754 static ssize_t
2755 errors_show(struct md_rdev *rdev, char *page)
2756 {
2757 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2758 }
2759 
2760 static ssize_t
2761 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2762 {
2763 	char *e;
2764 	unsigned long n = simple_strtoul(buf, &e, 10);
2765 	if (*buf && (*e == 0 || *e == '\n')) {
2766 		atomic_set(&rdev->corrected_errors, n);
2767 		return len;
2768 	}
2769 	return -EINVAL;
2770 }
2771 static struct rdev_sysfs_entry rdev_errors =
2772 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2773 
2774 static ssize_t
2775 slot_show(struct md_rdev *rdev, char *page)
2776 {
2777 	if (rdev->raid_disk < 0)
2778 		return sprintf(page, "none\n");
2779 	else
2780 		return sprintf(page, "%d\n", rdev->raid_disk);
2781 }
2782 
2783 static ssize_t
2784 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2785 {
2786 	char *e;
2787 	int err;
2788 	int slot = simple_strtoul(buf, &e, 10);
2789 	if (strncmp(buf, "none", 4)==0)
2790 		slot = -1;
2791 	else if (e==buf || (*e && *e!= '\n'))
2792 		return -EINVAL;
2793 	if (rdev->mddev->pers && slot == -1) {
2794 		/* Setting 'slot' on an active array requires also
2795 		 * updating the 'rd%d' link, and communicating
2796 		 * with the personality with ->hot_*_disk.
2797 		 * For now we only support removing
2798 		 * failed/spare devices.  This normally happens automatically,
2799 		 * but not when the metadata is externally managed.
2800 		 */
2801 		if (rdev->raid_disk == -1)
2802 			return -EEXIST;
2803 		/* personality does all needed checks */
2804 		if (rdev->mddev->pers->hot_remove_disk == NULL)
2805 			return -EINVAL;
2806 		err = rdev->mddev->pers->
2807 			hot_remove_disk(rdev->mddev, rdev);
2808 		if (err)
2809 			return err;
2810 		sysfs_unlink_rdev(rdev->mddev, rdev);
2811 		rdev->raid_disk = -1;
2812 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2813 		md_wakeup_thread(rdev->mddev->thread);
2814 	} else if (rdev->mddev->pers) {
2815 		/* Activating a spare .. or possibly reactivating
2816 		 * if we ever get bitmaps working here.
2817 		 */
2818 
2819 		if (rdev->raid_disk != -1)
2820 			return -EBUSY;
2821 
2822 		if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2823 			return -EBUSY;
2824 
2825 		if (rdev->mddev->pers->hot_add_disk == NULL)
2826 			return -EINVAL;
2827 
2828 		if (slot >= rdev->mddev->raid_disks &&
2829 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2830 			return -ENOSPC;
2831 
2832 		rdev->raid_disk = slot;
2833 		if (test_bit(In_sync, &rdev->flags))
2834 			rdev->saved_raid_disk = slot;
2835 		else
2836 			rdev->saved_raid_disk = -1;
2837 		clear_bit(In_sync, &rdev->flags);
2838 		err = rdev->mddev->pers->
2839 			hot_add_disk(rdev->mddev, rdev);
2840 		if (err) {
2841 			rdev->raid_disk = -1;
2842 			return err;
2843 		} else
2844 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2845 		if (sysfs_link_rdev(rdev->mddev, rdev))
2846 			/* failure here is OK */;
2847 		/* don't wakeup anyone, leave that to userspace. */
2848 	} else {
2849 		if (slot >= rdev->mddev->raid_disks &&
2850 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2851 			return -ENOSPC;
2852 		rdev->raid_disk = slot;
2853 		/* assume it is working */
2854 		clear_bit(Faulty, &rdev->flags);
2855 		clear_bit(WriteMostly, &rdev->flags);
2856 		set_bit(In_sync, &rdev->flags);
2857 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2858 	}
2859 	return len;
2860 }
2861 
2862 
2863 static struct rdev_sysfs_entry rdev_slot =
2864 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2865 
2866 static ssize_t
2867 offset_show(struct md_rdev *rdev, char *page)
2868 {
2869 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2870 }
2871 
2872 static ssize_t
2873 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2874 {
2875 	unsigned long long offset;
2876 	if (strict_strtoull(buf, 10, &offset) < 0)
2877 		return -EINVAL;
2878 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2879 		return -EBUSY;
2880 	if (rdev->sectors && rdev->mddev->external)
2881 		/* Must set offset before size, so overlap checks
2882 		 * can be sane */
2883 		return -EBUSY;
2884 	rdev->data_offset = offset;
2885 	rdev->new_data_offset = offset;
2886 	return len;
2887 }
2888 
2889 static struct rdev_sysfs_entry rdev_offset =
2890 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2891 
2892 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2893 {
2894 	return sprintf(page, "%llu\n",
2895 		       (unsigned long long)rdev->new_data_offset);
2896 }
2897 
2898 static ssize_t new_offset_store(struct md_rdev *rdev,
2899 				const char *buf, size_t len)
2900 {
2901 	unsigned long long new_offset;
2902 	struct mddev *mddev = rdev->mddev;
2903 
2904 	if (strict_strtoull(buf, 10, &new_offset) < 0)
2905 		return -EINVAL;
2906 
2907 	if (mddev->sync_thread)
2908 		return -EBUSY;
2909 	if (new_offset == rdev->data_offset)
2910 		/* reset is always permitted */
2911 		;
2912 	else if (new_offset > rdev->data_offset) {
2913 		/* must not push array size beyond rdev_sectors */
2914 		if (new_offset - rdev->data_offset
2915 		    + mddev->dev_sectors > rdev->sectors)
2916 				return -E2BIG;
2917 	}
2918 	/* Metadata worries about other space details. */
2919 
2920 	/* decreasing the offset is inconsistent with a backwards
2921 	 * reshape.
2922 	 */
2923 	if (new_offset < rdev->data_offset &&
2924 	    mddev->reshape_backwards)
2925 		return -EINVAL;
2926 	/* Increasing offset is inconsistent with forwards
2927 	 * reshape.  reshape_direction should be set to
2928 	 * 'backwards' first.
2929 	 */
2930 	if (new_offset > rdev->data_offset &&
2931 	    !mddev->reshape_backwards)
2932 		return -EINVAL;
2933 
2934 	if (mddev->pers && mddev->persistent &&
2935 	    !super_types[mddev->major_version]
2936 	    .allow_new_offset(rdev, new_offset))
2937 		return -E2BIG;
2938 	rdev->new_data_offset = new_offset;
2939 	if (new_offset > rdev->data_offset)
2940 		mddev->reshape_backwards = 1;
2941 	else if (new_offset < rdev->data_offset)
2942 		mddev->reshape_backwards = 0;
2943 
2944 	return len;
2945 }
2946 static struct rdev_sysfs_entry rdev_new_offset =
2947 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2948 
2949 static ssize_t
2950 rdev_size_show(struct md_rdev *rdev, char *page)
2951 {
2952 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2953 }
2954 
2955 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2956 {
2957 	/* check if two start/length pairs overlap */
2958 	if (s1+l1 <= s2)
2959 		return 0;
2960 	if (s2+l2 <= s1)
2961 		return 0;
2962 	return 1;
2963 }
2964 
2965 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2966 {
2967 	unsigned long long blocks;
2968 	sector_t new;
2969 
2970 	if (strict_strtoull(buf, 10, &blocks) < 0)
2971 		return -EINVAL;
2972 
2973 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2974 		return -EINVAL; /* sector conversion overflow */
2975 
2976 	new = blocks * 2;
2977 	if (new != blocks * 2)
2978 		return -EINVAL; /* unsigned long long to sector_t overflow */
2979 
2980 	*sectors = new;
2981 	return 0;
2982 }
2983 
2984 static ssize_t
2985 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2986 {
2987 	struct mddev *my_mddev = rdev->mddev;
2988 	sector_t oldsectors = rdev->sectors;
2989 	sector_t sectors;
2990 
2991 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2992 		return -EINVAL;
2993 	if (rdev->data_offset != rdev->new_data_offset)
2994 		return -EINVAL; /* too confusing */
2995 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2996 		if (my_mddev->persistent) {
2997 			sectors = super_types[my_mddev->major_version].
2998 				rdev_size_change(rdev, sectors);
2999 			if (!sectors)
3000 				return -EBUSY;
3001 		} else if (!sectors)
3002 			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
3003 				rdev->data_offset;
3004 	}
3005 	if (sectors < my_mddev->dev_sectors)
3006 		return -EINVAL; /* component must fit device */
3007 
3008 	rdev->sectors = sectors;
3009 	if (sectors > oldsectors && my_mddev->external) {
3010 		/* need to check that all other rdevs with the same ->bdev
3011 		 * do not overlap.  We need to unlock the mddev to avoid
3012 		 * a deadlock.  We have already changed rdev->sectors, and if
3013 		 * we have to change it back, we will have the lock again.
3014 		 */
3015 		struct mddev *mddev;
3016 		int overlap = 0;
3017 		struct list_head *tmp;
3018 
3019 		mddev_unlock(my_mddev);
3020 		for_each_mddev(mddev, tmp) {
3021 			struct md_rdev *rdev2;
3022 
3023 			mddev_lock(mddev);
3024 			rdev_for_each(rdev2, mddev)
3025 				if (rdev->bdev == rdev2->bdev &&
3026 				    rdev != rdev2 &&
3027 				    overlaps(rdev->data_offset, rdev->sectors,
3028 					     rdev2->data_offset,
3029 					     rdev2->sectors)) {
3030 					overlap = 1;
3031 					break;
3032 				}
3033 			mddev_unlock(mddev);
3034 			if (overlap) {
3035 				mddev_put(mddev);
3036 				break;
3037 			}
3038 		}
3039 		mddev_lock(my_mddev);
3040 		if (overlap) {
3041 			/* Someone else could have slipped in a size
3042 			 * change here, but doing so is just silly.
3043 			 * We put oldsectors back because we *know* it is
3044 			 * safe, and trust userspace not to race with
3045 			 * itself
3046 			 */
3047 			rdev->sectors = oldsectors;
3048 			return -EBUSY;
3049 		}
3050 	}
3051 	return len;
3052 }
3053 
3054 static struct rdev_sysfs_entry rdev_size =
3055 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3056 
3057 
3058 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3059 {
3060 	unsigned long long recovery_start = rdev->recovery_offset;
3061 
3062 	if (test_bit(In_sync, &rdev->flags) ||
3063 	    recovery_start == MaxSector)
3064 		return sprintf(page, "none\n");
3065 
3066 	return sprintf(page, "%llu\n", recovery_start);
3067 }
3068 
3069 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3070 {
3071 	unsigned long long recovery_start;
3072 
3073 	if (cmd_match(buf, "none"))
3074 		recovery_start = MaxSector;
3075 	else if (strict_strtoull(buf, 10, &recovery_start))
3076 		return -EINVAL;
3077 
3078 	if (rdev->mddev->pers &&
3079 	    rdev->raid_disk >= 0)
3080 		return -EBUSY;
3081 
3082 	rdev->recovery_offset = recovery_start;
3083 	if (recovery_start == MaxSector)
3084 		set_bit(In_sync, &rdev->flags);
3085 	else
3086 		clear_bit(In_sync, &rdev->flags);
3087 	return len;
3088 }
3089 
3090 static struct rdev_sysfs_entry rdev_recovery_start =
3091 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3092 
3093 
3094 static ssize_t
3095 badblocks_show(struct badblocks *bb, char *page, int unack);
3096 static ssize_t
3097 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
3098 
3099 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3100 {
3101 	return badblocks_show(&rdev->badblocks, page, 0);
3102 }
3103 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3104 {
3105 	int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3106 	/* Maybe that ack was all we needed */
3107 	if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3108 		wake_up(&rdev->blocked_wait);
3109 	return rv;
3110 }
3111 static struct rdev_sysfs_entry rdev_bad_blocks =
3112 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3113 
3114 
3115 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3116 {
3117 	return badblocks_show(&rdev->badblocks, page, 1);
3118 }
3119 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3120 {
3121 	return badblocks_store(&rdev->badblocks, page, len, 1);
3122 }
3123 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3124 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3125 
3126 static struct attribute *rdev_default_attrs[] = {
3127 	&rdev_state.attr,
3128 	&rdev_errors.attr,
3129 	&rdev_slot.attr,
3130 	&rdev_offset.attr,
3131 	&rdev_new_offset.attr,
3132 	&rdev_size.attr,
3133 	&rdev_recovery_start.attr,
3134 	&rdev_bad_blocks.attr,
3135 	&rdev_unack_bad_blocks.attr,
3136 	NULL,
3137 };
3138 static ssize_t
3139 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3140 {
3141 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3142 	struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3143 	struct mddev *mddev = rdev->mddev;
3144 	ssize_t rv;
3145 
3146 	if (!entry->show)
3147 		return -EIO;
3148 
3149 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
3150 	if (!rv) {
3151 		if (rdev->mddev == NULL)
3152 			rv = -EBUSY;
3153 		else
3154 			rv = entry->show(rdev, page);
3155 		mddev_unlock(mddev);
3156 	}
3157 	return rv;
3158 }
3159 
3160 static ssize_t
3161 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3162 	      const char *page, size_t length)
3163 {
3164 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3165 	struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3166 	ssize_t rv;
3167 	struct mddev *mddev = rdev->mddev;
3168 
3169 	if (!entry->store)
3170 		return -EIO;
3171 	if (!capable(CAP_SYS_ADMIN))
3172 		return -EACCES;
3173 	rv = mddev ? mddev_lock(mddev): -EBUSY;
3174 	if (!rv) {
3175 		if (rdev->mddev == NULL)
3176 			rv = -EBUSY;
3177 		else
3178 			rv = entry->store(rdev, page, length);
3179 		mddev_unlock(mddev);
3180 	}
3181 	return rv;
3182 }
3183 
3184 static void rdev_free(struct kobject *ko)
3185 {
3186 	struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3187 	kfree(rdev);
3188 }
3189 static const struct sysfs_ops rdev_sysfs_ops = {
3190 	.show		= rdev_attr_show,
3191 	.store		= rdev_attr_store,
3192 };
3193 static struct kobj_type rdev_ktype = {
3194 	.release	= rdev_free,
3195 	.sysfs_ops	= &rdev_sysfs_ops,
3196 	.default_attrs	= rdev_default_attrs,
3197 };
3198 
3199 int md_rdev_init(struct md_rdev *rdev)
3200 {
3201 	rdev->desc_nr = -1;
3202 	rdev->saved_raid_disk = -1;
3203 	rdev->raid_disk = -1;
3204 	rdev->flags = 0;
3205 	rdev->data_offset = 0;
3206 	rdev->new_data_offset = 0;
3207 	rdev->sb_events = 0;
3208 	rdev->last_read_error.tv_sec  = 0;
3209 	rdev->last_read_error.tv_nsec = 0;
3210 	rdev->sb_loaded = 0;
3211 	rdev->bb_page = NULL;
3212 	atomic_set(&rdev->nr_pending, 0);
3213 	atomic_set(&rdev->read_errors, 0);
3214 	atomic_set(&rdev->corrected_errors, 0);
3215 
3216 	INIT_LIST_HEAD(&rdev->same_set);
3217 	init_waitqueue_head(&rdev->blocked_wait);
3218 
3219 	/* Add space to store bad block list.
3220 	 * This reserves the space even on arrays where it cannot
3221 	 * be used - I wonder if that matters
3222 	 */
3223 	rdev->badblocks.count = 0;
3224 	rdev->badblocks.shift = 0;
3225 	rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3226 	seqlock_init(&rdev->badblocks.lock);
3227 	if (rdev->badblocks.page == NULL)
3228 		return -ENOMEM;
3229 
3230 	return 0;
3231 }
3232 EXPORT_SYMBOL_GPL(md_rdev_init);
3233 /*
3234  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3235  *
3236  * mark the device faulty if:
3237  *
3238  *   - the device is nonexistent (zero size)
3239  *   - the device has no valid superblock
3240  *
3241  * a faulty rdev _never_ has rdev->sb set.
3242  */
3243 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3244 {
3245 	char b[BDEVNAME_SIZE];
3246 	int err;
3247 	struct md_rdev *rdev;
3248 	sector_t size;
3249 
3250 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3251 	if (!rdev) {
3252 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
3253 		return ERR_PTR(-ENOMEM);
3254 	}
3255 
3256 	err = md_rdev_init(rdev);
3257 	if (err)
3258 		goto abort_free;
3259 	err = alloc_disk_sb(rdev);
3260 	if (err)
3261 		goto abort_free;
3262 
3263 	err = lock_rdev(rdev, newdev, super_format == -2);
3264 	if (err)
3265 		goto abort_free;
3266 
3267 	kobject_init(&rdev->kobj, &rdev_ktype);
3268 
3269 	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3270 	if (!size) {
3271 		printk(KERN_WARNING
3272 			"md: %s has zero or unknown size, marking faulty!\n",
3273 			bdevname(rdev->bdev,b));
3274 		err = -EINVAL;
3275 		goto abort_free;
3276 	}
3277 
3278 	if (super_format >= 0) {
3279 		err = super_types[super_format].
3280 			load_super(rdev, NULL, super_minor);
3281 		if (err == -EINVAL) {
3282 			printk(KERN_WARNING
3283 				"md: %s does not have a valid v%d.%d "
3284 			       "superblock, not importing!\n",
3285 				bdevname(rdev->bdev,b),
3286 			       super_format, super_minor);
3287 			goto abort_free;
3288 		}
3289 		if (err < 0) {
3290 			printk(KERN_WARNING
3291 				"md: could not read %s's sb, not importing!\n",
3292 				bdevname(rdev->bdev,b));
3293 			goto abort_free;
3294 		}
3295 	}
3296 	if (super_format == -1)
3297 		/* hot-add for 0.90, or non-persistent: so no badblocks */
3298 		rdev->badblocks.shift = -1;
3299 
3300 	return rdev;
3301 
3302 abort_free:
3303 	if (rdev->bdev)
3304 		unlock_rdev(rdev);
3305 	md_rdev_clear(rdev);
3306 	kfree(rdev);
3307 	return ERR_PTR(err);
3308 }
3309 
3310 /*
3311  * Check a full RAID array for plausibility
3312  */
3313 
3314 
3315 static void analyze_sbs(struct mddev * mddev)
3316 {
3317 	int i;
3318 	struct md_rdev *rdev, *freshest, *tmp;
3319 	char b[BDEVNAME_SIZE];
3320 
3321 	freshest = NULL;
3322 	rdev_for_each_safe(rdev, tmp, mddev)
3323 		switch (super_types[mddev->major_version].
3324 			load_super(rdev, freshest, mddev->minor_version)) {
3325 		case 1:
3326 			freshest = rdev;
3327 			break;
3328 		case 0:
3329 			break;
3330 		default:
3331 			printk( KERN_ERR \
3332 				"md: fatal superblock inconsistency in %s"
3333 				" -- removing from array\n",
3334 				bdevname(rdev->bdev,b));
3335 			kick_rdev_from_array(rdev);
3336 		}
3337 
3338 
3339 	super_types[mddev->major_version].
3340 		validate_super(mddev, freshest);
3341 
3342 	i = 0;
3343 	rdev_for_each_safe(rdev, tmp, mddev) {
3344 		if (mddev->max_disks &&
3345 		    (rdev->desc_nr >= mddev->max_disks ||
3346 		     i > mddev->max_disks)) {
3347 			printk(KERN_WARNING
3348 			       "md: %s: %s: only %d devices permitted\n",
3349 			       mdname(mddev), bdevname(rdev->bdev, b),
3350 			       mddev->max_disks);
3351 			kick_rdev_from_array(rdev);
3352 			continue;
3353 		}
3354 		if (rdev != freshest)
3355 			if (super_types[mddev->major_version].
3356 			    validate_super(mddev, rdev)) {
3357 				printk(KERN_WARNING "md: kicking non-fresh %s"
3358 					" from array!\n",
3359 					bdevname(rdev->bdev,b));
3360 				kick_rdev_from_array(rdev);
3361 				continue;
3362 			}
3363 		if (mddev->level == LEVEL_MULTIPATH) {
3364 			rdev->desc_nr = i++;
3365 			rdev->raid_disk = rdev->desc_nr;
3366 			set_bit(In_sync, &rdev->flags);
3367 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3368 			rdev->raid_disk = -1;
3369 			clear_bit(In_sync, &rdev->flags);
3370 		}
3371 	}
3372 }
3373 
3374 /* Read a fixed-point number.
3375  * Numbers in sysfs attributes should be in "standard" units where
3376  * possible, so time should be in seconds.
3377  * However we internally use a a much smaller unit such as
3378  * milliseconds or jiffies.
3379  * This function takes a decimal number with a possible fractional
3380  * component, and produces an integer which is the result of
3381  * multiplying that number by 10^'scale'.
3382  * all without any floating-point arithmetic.
3383  */
3384 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3385 {
3386 	unsigned long result = 0;
3387 	long decimals = -1;
3388 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3389 		if (*cp == '.')
3390 			decimals = 0;
3391 		else if (decimals < scale) {
3392 			unsigned int value;
3393 			value = *cp - '0';
3394 			result = result * 10 + value;
3395 			if (decimals >= 0)
3396 				decimals++;
3397 		}
3398 		cp++;
3399 	}
3400 	if (*cp == '\n')
3401 		cp++;
3402 	if (*cp)
3403 		return -EINVAL;
3404 	if (decimals < 0)
3405 		decimals = 0;
3406 	while (decimals < scale) {
3407 		result *= 10;
3408 		decimals ++;
3409 	}
3410 	*res = result;
3411 	return 0;
3412 }
3413 
3414 
3415 static void md_safemode_timeout(unsigned long data);
3416 
3417 static ssize_t
3418 safe_delay_show(struct mddev *mddev, char *page)
3419 {
3420 	int msec = (mddev->safemode_delay*1000)/HZ;
3421 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3422 }
3423 static ssize_t
3424 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3425 {
3426 	unsigned long msec;
3427 
3428 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3429 		return -EINVAL;
3430 	if (msec == 0)
3431 		mddev->safemode_delay = 0;
3432 	else {
3433 		unsigned long old_delay = mddev->safemode_delay;
3434 		mddev->safemode_delay = (msec*HZ)/1000;
3435 		if (mddev->safemode_delay == 0)
3436 			mddev->safemode_delay = 1;
3437 		if (mddev->safemode_delay < old_delay)
3438 			md_safemode_timeout((unsigned long)mddev);
3439 	}
3440 	return len;
3441 }
3442 static struct md_sysfs_entry md_safe_delay =
3443 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3444 
3445 static ssize_t
3446 level_show(struct mddev *mddev, char *page)
3447 {
3448 	struct md_personality *p = mddev->pers;
3449 	if (p)
3450 		return sprintf(page, "%s\n", p->name);
3451 	else if (mddev->clevel[0])
3452 		return sprintf(page, "%s\n", mddev->clevel);
3453 	else if (mddev->level != LEVEL_NONE)
3454 		return sprintf(page, "%d\n", mddev->level);
3455 	else
3456 		return 0;
3457 }
3458 
3459 static ssize_t
3460 level_store(struct mddev *mddev, const char *buf, size_t len)
3461 {
3462 	char clevel[16];
3463 	ssize_t rv = len;
3464 	struct md_personality *pers;
3465 	long level;
3466 	void *priv;
3467 	struct md_rdev *rdev;
3468 
3469 	if (mddev->pers == NULL) {
3470 		if (len == 0)
3471 			return 0;
3472 		if (len >= sizeof(mddev->clevel))
3473 			return -ENOSPC;
3474 		strncpy(mddev->clevel, buf, len);
3475 		if (mddev->clevel[len-1] == '\n')
3476 			len--;
3477 		mddev->clevel[len] = 0;
3478 		mddev->level = LEVEL_NONE;
3479 		return rv;
3480 	}
3481 
3482 	/* request to change the personality.  Need to ensure:
3483 	 *  - array is not engaged in resync/recovery/reshape
3484 	 *  - old personality can be suspended
3485 	 *  - new personality will access other array.
3486 	 */
3487 
3488 	if (mddev->sync_thread ||
3489 	    mddev->reshape_position != MaxSector ||
3490 	    mddev->sysfs_active)
3491 		return -EBUSY;
3492 
3493 	if (!mddev->pers->quiesce) {
3494 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3495 		       mdname(mddev), mddev->pers->name);
3496 		return -EINVAL;
3497 	}
3498 
3499 	/* Now find the new personality */
3500 	if (len == 0 || len >= sizeof(clevel))
3501 		return -EINVAL;
3502 	strncpy(clevel, buf, len);
3503 	if (clevel[len-1] == '\n')
3504 		len--;
3505 	clevel[len] = 0;
3506 	if (strict_strtol(clevel, 10, &level))
3507 		level = LEVEL_NONE;
3508 
3509 	if (request_module("md-%s", clevel) != 0)
3510 		request_module("md-level-%s", clevel);
3511 	spin_lock(&pers_lock);
3512 	pers = find_pers(level, clevel);
3513 	if (!pers || !try_module_get(pers->owner)) {
3514 		spin_unlock(&pers_lock);
3515 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3516 		return -EINVAL;
3517 	}
3518 	spin_unlock(&pers_lock);
3519 
3520 	if (pers == mddev->pers) {
3521 		/* Nothing to do! */
3522 		module_put(pers->owner);
3523 		return rv;
3524 	}
3525 	if (!pers->takeover) {
3526 		module_put(pers->owner);
3527 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3528 		       mdname(mddev), clevel);
3529 		return -EINVAL;
3530 	}
3531 
3532 	rdev_for_each(rdev, mddev)
3533 		rdev->new_raid_disk = rdev->raid_disk;
3534 
3535 	/* ->takeover must set new_* and/or delta_disks
3536 	 * if it succeeds, and may set them when it fails.
3537 	 */
3538 	priv = pers->takeover(mddev);
3539 	if (IS_ERR(priv)) {
3540 		mddev->new_level = mddev->level;
3541 		mddev->new_layout = mddev->layout;
3542 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3543 		mddev->raid_disks -= mddev->delta_disks;
3544 		mddev->delta_disks = 0;
3545 		mddev->reshape_backwards = 0;
3546 		module_put(pers->owner);
3547 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3548 		       mdname(mddev), clevel);
3549 		return PTR_ERR(priv);
3550 	}
3551 
3552 	/* Looks like we have a winner */
3553 	mddev_suspend(mddev);
3554 	mddev->pers->stop(mddev);
3555 
3556 	if (mddev->pers->sync_request == NULL &&
3557 	    pers->sync_request != NULL) {
3558 		/* need to add the md_redundancy_group */
3559 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3560 			printk(KERN_WARNING
3561 			       "md: cannot register extra attributes for %s\n",
3562 			       mdname(mddev));
3563 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3564 	}
3565 	if (mddev->pers->sync_request != NULL &&
3566 	    pers->sync_request == NULL) {
3567 		/* need to remove the md_redundancy_group */
3568 		if (mddev->to_remove == NULL)
3569 			mddev->to_remove = &md_redundancy_group;
3570 	}
3571 
3572 	if (mddev->pers->sync_request == NULL &&
3573 	    mddev->external) {
3574 		/* We are converting from a no-redundancy array
3575 		 * to a redundancy array and metadata is managed
3576 		 * externally so we need to be sure that writes
3577 		 * won't block due to a need to transition
3578 		 *      clean->dirty
3579 		 * until external management is started.
3580 		 */
3581 		mddev->in_sync = 0;
3582 		mddev->safemode_delay = 0;
3583 		mddev->safemode = 0;
3584 	}
3585 
3586 	rdev_for_each(rdev, mddev) {
3587 		if (rdev->raid_disk < 0)
3588 			continue;
3589 		if (rdev->new_raid_disk >= mddev->raid_disks)
3590 			rdev->new_raid_disk = -1;
3591 		if (rdev->new_raid_disk == rdev->raid_disk)
3592 			continue;
3593 		sysfs_unlink_rdev(mddev, rdev);
3594 	}
3595 	rdev_for_each(rdev, mddev) {
3596 		if (rdev->raid_disk < 0)
3597 			continue;
3598 		if (rdev->new_raid_disk == rdev->raid_disk)
3599 			continue;
3600 		rdev->raid_disk = rdev->new_raid_disk;
3601 		if (rdev->raid_disk < 0)
3602 			clear_bit(In_sync, &rdev->flags);
3603 		else {
3604 			if (sysfs_link_rdev(mddev, rdev))
3605 				printk(KERN_WARNING "md: cannot register rd%d"
3606 				       " for %s after level change\n",
3607 				       rdev->raid_disk, mdname(mddev));
3608 		}
3609 	}
3610 
3611 	module_put(mddev->pers->owner);
3612 	mddev->pers = pers;
3613 	mddev->private = priv;
3614 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3615 	mddev->level = mddev->new_level;
3616 	mddev->layout = mddev->new_layout;
3617 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3618 	mddev->delta_disks = 0;
3619 	mddev->reshape_backwards = 0;
3620 	mddev->degraded = 0;
3621 	if (mddev->pers->sync_request == NULL) {
3622 		/* this is now an array without redundancy, so
3623 		 * it must always be in_sync
3624 		 */
3625 		mddev->in_sync = 1;
3626 		del_timer_sync(&mddev->safemode_timer);
3627 	}
3628 	pers->run(mddev);
3629 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3630 	mddev_resume(mddev);
3631 	sysfs_notify(&mddev->kobj, NULL, "level");
3632 	md_new_event(mddev);
3633 	return rv;
3634 }
3635 
3636 static struct md_sysfs_entry md_level =
3637 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3638 
3639 
3640 static ssize_t
3641 layout_show(struct mddev *mddev, char *page)
3642 {
3643 	/* just a number, not meaningful for all levels */
3644 	if (mddev->reshape_position != MaxSector &&
3645 	    mddev->layout != mddev->new_layout)
3646 		return sprintf(page, "%d (%d)\n",
3647 			       mddev->new_layout, mddev->layout);
3648 	return sprintf(page, "%d\n", mddev->layout);
3649 }
3650 
3651 static ssize_t
3652 layout_store(struct mddev *mddev, const char *buf, size_t len)
3653 {
3654 	char *e;
3655 	unsigned long n = simple_strtoul(buf, &e, 10);
3656 
3657 	if (!*buf || (*e && *e != '\n'))
3658 		return -EINVAL;
3659 
3660 	if (mddev->pers) {
3661 		int err;
3662 		if (mddev->pers->check_reshape == NULL)
3663 			return -EBUSY;
3664 		mddev->new_layout = n;
3665 		err = mddev->pers->check_reshape(mddev);
3666 		if (err) {
3667 			mddev->new_layout = mddev->layout;
3668 			return err;
3669 		}
3670 	} else {
3671 		mddev->new_layout = n;
3672 		if (mddev->reshape_position == MaxSector)
3673 			mddev->layout = n;
3674 	}
3675 	return len;
3676 }
3677 static struct md_sysfs_entry md_layout =
3678 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3679 
3680 
3681 static ssize_t
3682 raid_disks_show(struct mddev *mddev, char *page)
3683 {
3684 	if (mddev->raid_disks == 0)
3685 		return 0;
3686 	if (mddev->reshape_position != MaxSector &&
3687 	    mddev->delta_disks != 0)
3688 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3689 			       mddev->raid_disks - mddev->delta_disks);
3690 	return sprintf(page, "%d\n", mddev->raid_disks);
3691 }
3692 
3693 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3694 
3695 static ssize_t
3696 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3697 {
3698 	char *e;
3699 	int rv = 0;
3700 	unsigned long n = simple_strtoul(buf, &e, 10);
3701 
3702 	if (!*buf || (*e && *e != '\n'))
3703 		return -EINVAL;
3704 
3705 	if (mddev->pers)
3706 		rv = update_raid_disks(mddev, n);
3707 	else if (mddev->reshape_position != MaxSector) {
3708 		struct md_rdev *rdev;
3709 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3710 
3711 		rdev_for_each(rdev, mddev) {
3712 			if (olddisks < n &&
3713 			    rdev->data_offset < rdev->new_data_offset)
3714 				return -EINVAL;
3715 			if (olddisks > n &&
3716 			    rdev->data_offset > rdev->new_data_offset)
3717 				return -EINVAL;
3718 		}
3719 		mddev->delta_disks = n - olddisks;
3720 		mddev->raid_disks = n;
3721 		mddev->reshape_backwards = (mddev->delta_disks < 0);
3722 	} else
3723 		mddev->raid_disks = n;
3724 	return rv ? rv : len;
3725 }
3726 static struct md_sysfs_entry md_raid_disks =
3727 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3728 
3729 static ssize_t
3730 chunk_size_show(struct mddev *mddev, char *page)
3731 {
3732 	if (mddev->reshape_position != MaxSector &&
3733 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3734 		return sprintf(page, "%d (%d)\n",
3735 			       mddev->new_chunk_sectors << 9,
3736 			       mddev->chunk_sectors << 9);
3737 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3738 }
3739 
3740 static ssize_t
3741 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3742 {
3743 	char *e;
3744 	unsigned long n = simple_strtoul(buf, &e, 10);
3745 
3746 	if (!*buf || (*e && *e != '\n'))
3747 		return -EINVAL;
3748 
3749 	if (mddev->pers) {
3750 		int err;
3751 		if (mddev->pers->check_reshape == NULL)
3752 			return -EBUSY;
3753 		mddev->new_chunk_sectors = n >> 9;
3754 		err = mddev->pers->check_reshape(mddev);
3755 		if (err) {
3756 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3757 			return err;
3758 		}
3759 	} else {
3760 		mddev->new_chunk_sectors = n >> 9;
3761 		if (mddev->reshape_position == MaxSector)
3762 			mddev->chunk_sectors = n >> 9;
3763 	}
3764 	return len;
3765 }
3766 static struct md_sysfs_entry md_chunk_size =
3767 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3768 
3769 static ssize_t
3770 resync_start_show(struct mddev *mddev, char *page)
3771 {
3772 	if (mddev->recovery_cp == MaxSector)
3773 		return sprintf(page, "none\n");
3774 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3775 }
3776 
3777 static ssize_t
3778 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3779 {
3780 	char *e;
3781 	unsigned long long n = simple_strtoull(buf, &e, 10);
3782 
3783 	if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3784 		return -EBUSY;
3785 	if (cmd_match(buf, "none"))
3786 		n = MaxSector;
3787 	else if (!*buf || (*e && *e != '\n'))
3788 		return -EINVAL;
3789 
3790 	mddev->recovery_cp = n;
3791 	return len;
3792 }
3793 static struct md_sysfs_entry md_resync_start =
3794 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3795 
3796 /*
3797  * The array state can be:
3798  *
3799  * clear
3800  *     No devices, no size, no level
3801  *     Equivalent to STOP_ARRAY ioctl
3802  * inactive
3803  *     May have some settings, but array is not active
3804  *        all IO results in error
3805  *     When written, doesn't tear down array, but just stops it
3806  * suspended (not supported yet)
3807  *     All IO requests will block. The array can be reconfigured.
3808  *     Writing this, if accepted, will block until array is quiescent
3809  * readonly
3810  *     no resync can happen.  no superblocks get written.
3811  *     write requests fail
3812  * read-auto
3813  *     like readonly, but behaves like 'clean' on a write request.
3814  *
3815  * clean - no pending writes, but otherwise active.
3816  *     When written to inactive array, starts without resync
3817  *     If a write request arrives then
3818  *       if metadata is known, mark 'dirty' and switch to 'active'.
3819  *       if not known, block and switch to write-pending
3820  *     If written to an active array that has pending writes, then fails.
3821  * active
3822  *     fully active: IO and resync can be happening.
3823  *     When written to inactive array, starts with resync
3824  *
3825  * write-pending
3826  *     clean, but writes are blocked waiting for 'active' to be written.
3827  *
3828  * active-idle
3829  *     like active, but no writes have been seen for a while (100msec).
3830  *
3831  */
3832 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3833 		   write_pending, active_idle, bad_word};
3834 static char *array_states[] = {
3835 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3836 	"write-pending", "active-idle", NULL };
3837 
3838 static int match_word(const char *word, char **list)
3839 {
3840 	int n;
3841 	for (n=0; list[n]; n++)
3842 		if (cmd_match(word, list[n]))
3843 			break;
3844 	return n;
3845 }
3846 
3847 static ssize_t
3848 array_state_show(struct mddev *mddev, char *page)
3849 {
3850 	enum array_state st = inactive;
3851 
3852 	if (mddev->pers)
3853 		switch(mddev->ro) {
3854 		case 1:
3855 			st = readonly;
3856 			break;
3857 		case 2:
3858 			st = read_auto;
3859 			break;
3860 		case 0:
3861 			if (mddev->in_sync)
3862 				st = clean;
3863 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3864 				st = write_pending;
3865 			else if (mddev->safemode)
3866 				st = active_idle;
3867 			else
3868 				st = active;
3869 		}
3870 	else {
3871 		if (list_empty(&mddev->disks) &&
3872 		    mddev->raid_disks == 0 &&
3873 		    mddev->dev_sectors == 0)
3874 			st = clear;
3875 		else
3876 			st = inactive;
3877 	}
3878 	return sprintf(page, "%s\n", array_states[st]);
3879 }
3880 
3881 static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
3882 static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
3883 static int do_md_run(struct mddev * mddev);
3884 static int restart_array(struct mddev *mddev);
3885 
3886 static ssize_t
3887 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3888 {
3889 	int err = -EINVAL;
3890 	enum array_state st = match_word(buf, array_states);
3891 	switch(st) {
3892 	case bad_word:
3893 		break;
3894 	case clear:
3895 		/* stopping an active array */
3896 		err = do_md_stop(mddev, 0, NULL);
3897 		break;
3898 	case inactive:
3899 		/* stopping an active array */
3900 		if (mddev->pers)
3901 			err = do_md_stop(mddev, 2, NULL);
3902 		else
3903 			err = 0; /* already inactive */
3904 		break;
3905 	case suspended:
3906 		break; /* not supported yet */
3907 	case readonly:
3908 		if (mddev->pers)
3909 			err = md_set_readonly(mddev, NULL);
3910 		else {
3911 			mddev->ro = 1;
3912 			set_disk_ro(mddev->gendisk, 1);
3913 			err = do_md_run(mddev);
3914 		}
3915 		break;
3916 	case read_auto:
3917 		if (mddev->pers) {
3918 			if (mddev->ro == 0)
3919 				err = md_set_readonly(mddev, NULL);
3920 			else if (mddev->ro == 1)
3921 				err = restart_array(mddev);
3922 			if (err == 0) {
3923 				mddev->ro = 2;
3924 				set_disk_ro(mddev->gendisk, 0);
3925 			}
3926 		} else {
3927 			mddev->ro = 2;
3928 			err = do_md_run(mddev);
3929 		}
3930 		break;
3931 	case clean:
3932 		if (mddev->pers) {
3933 			restart_array(mddev);
3934 			spin_lock_irq(&mddev->write_lock);
3935 			if (atomic_read(&mddev->writes_pending) == 0) {
3936 				if (mddev->in_sync == 0) {
3937 					mddev->in_sync = 1;
3938 					if (mddev->safemode == 1)
3939 						mddev->safemode = 0;
3940 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3941 				}
3942 				err = 0;
3943 			} else
3944 				err = -EBUSY;
3945 			spin_unlock_irq(&mddev->write_lock);
3946 		} else
3947 			err = -EINVAL;
3948 		break;
3949 	case active:
3950 		if (mddev->pers) {
3951 			restart_array(mddev);
3952 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3953 			wake_up(&mddev->sb_wait);
3954 			err = 0;
3955 		} else {
3956 			mddev->ro = 0;
3957 			set_disk_ro(mddev->gendisk, 0);
3958 			err = do_md_run(mddev);
3959 		}
3960 		break;
3961 	case write_pending:
3962 	case active_idle:
3963 		/* these cannot be set */
3964 		break;
3965 	}
3966 	if (err)
3967 		return err;
3968 	else {
3969 		if (mddev->hold_active == UNTIL_IOCTL)
3970 			mddev->hold_active = 0;
3971 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3972 		return len;
3973 	}
3974 }
3975 static struct md_sysfs_entry md_array_state =
3976 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3977 
3978 static ssize_t
3979 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
3980 	return sprintf(page, "%d\n",
3981 		       atomic_read(&mddev->max_corr_read_errors));
3982 }
3983 
3984 static ssize_t
3985 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
3986 {
3987 	char *e;
3988 	unsigned long n = simple_strtoul(buf, &e, 10);
3989 
3990 	if (*buf && (*e == 0 || *e == '\n')) {
3991 		atomic_set(&mddev->max_corr_read_errors, n);
3992 		return len;
3993 	}
3994 	return -EINVAL;
3995 }
3996 
3997 static struct md_sysfs_entry max_corr_read_errors =
3998 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3999 	max_corrected_read_errors_store);
4000 
4001 static ssize_t
4002 null_show(struct mddev *mddev, char *page)
4003 {
4004 	return -EINVAL;
4005 }
4006 
4007 static ssize_t
4008 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
4009 {
4010 	/* buf must be %d:%d\n? giving major and minor numbers */
4011 	/* The new device is added to the array.
4012 	 * If the array has a persistent superblock, we read the
4013 	 * superblock to initialise info and check validity.
4014 	 * Otherwise, only checking done is that in bind_rdev_to_array,
4015 	 * which mainly checks size.
4016 	 */
4017 	char *e;
4018 	int major = simple_strtoul(buf, &e, 10);
4019 	int minor;
4020 	dev_t dev;
4021 	struct md_rdev *rdev;
4022 	int err;
4023 
4024 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4025 		return -EINVAL;
4026 	minor = simple_strtoul(e+1, &e, 10);
4027 	if (*e && *e != '\n')
4028 		return -EINVAL;
4029 	dev = MKDEV(major, minor);
4030 	if (major != MAJOR(dev) ||
4031 	    minor != MINOR(dev))
4032 		return -EOVERFLOW;
4033 
4034 
4035 	if (mddev->persistent) {
4036 		rdev = md_import_device(dev, mddev->major_version,
4037 					mddev->minor_version);
4038 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4039 			struct md_rdev *rdev0
4040 				= list_entry(mddev->disks.next,
4041 					     struct md_rdev, same_set);
4042 			err = super_types[mddev->major_version]
4043 				.load_super(rdev, rdev0, mddev->minor_version);
4044 			if (err < 0)
4045 				goto out;
4046 		}
4047 	} else if (mddev->external)
4048 		rdev = md_import_device(dev, -2, -1);
4049 	else
4050 		rdev = md_import_device(dev, -1, -1);
4051 
4052 	if (IS_ERR(rdev))
4053 		return PTR_ERR(rdev);
4054 	err = bind_rdev_to_array(rdev, mddev);
4055  out:
4056 	if (err)
4057 		export_rdev(rdev);
4058 	return err ? err : len;
4059 }
4060 
4061 static struct md_sysfs_entry md_new_device =
4062 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4063 
4064 static ssize_t
4065 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4066 {
4067 	char *end;
4068 	unsigned long chunk, end_chunk;
4069 
4070 	if (!mddev->bitmap)
4071 		goto out;
4072 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4073 	while (*buf) {
4074 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
4075 		if (buf == end) break;
4076 		if (*end == '-') { /* range */
4077 			buf = end + 1;
4078 			end_chunk = simple_strtoul(buf, &end, 0);
4079 			if (buf == end) break;
4080 		}
4081 		if (*end && !isspace(*end)) break;
4082 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4083 		buf = skip_spaces(end);
4084 	}
4085 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4086 out:
4087 	return len;
4088 }
4089 
4090 static struct md_sysfs_entry md_bitmap =
4091 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4092 
4093 static ssize_t
4094 size_show(struct mddev *mddev, char *page)
4095 {
4096 	return sprintf(page, "%llu\n",
4097 		(unsigned long long)mddev->dev_sectors / 2);
4098 }
4099 
4100 static int update_size(struct mddev *mddev, sector_t num_sectors);
4101 
4102 static ssize_t
4103 size_store(struct mddev *mddev, const char *buf, size_t len)
4104 {
4105 	/* If array is inactive, we can reduce the component size, but
4106 	 * not increase it (except from 0).
4107 	 * If array is active, we can try an on-line resize
4108 	 */
4109 	sector_t sectors;
4110 	int err = strict_blocks_to_sectors(buf, &sectors);
4111 
4112 	if (err < 0)
4113 		return err;
4114 	if (mddev->pers) {
4115 		err = update_size(mddev, sectors);
4116 		md_update_sb(mddev, 1);
4117 	} else {
4118 		if (mddev->dev_sectors == 0 ||
4119 		    mddev->dev_sectors > sectors)
4120 			mddev->dev_sectors = sectors;
4121 		else
4122 			err = -ENOSPC;
4123 	}
4124 	return err ? err : len;
4125 }
4126 
4127 static struct md_sysfs_entry md_size =
4128 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4129 
4130 
4131 /* Metdata version.
4132  * This is one of
4133  *   'none' for arrays with no metadata (good luck...)
4134  *   'external' for arrays with externally managed metadata,
4135  * or N.M for internally known formats
4136  */
4137 static ssize_t
4138 metadata_show(struct mddev *mddev, char *page)
4139 {
4140 	if (mddev->persistent)
4141 		return sprintf(page, "%d.%d\n",
4142 			       mddev->major_version, mddev->minor_version);
4143 	else if (mddev->external)
4144 		return sprintf(page, "external:%s\n", mddev->metadata_type);
4145 	else
4146 		return sprintf(page, "none\n");
4147 }
4148 
4149 static ssize_t
4150 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4151 {
4152 	int major, minor;
4153 	char *e;
4154 	/* Changing the details of 'external' metadata is
4155 	 * always permitted.  Otherwise there must be
4156 	 * no devices attached to the array.
4157 	 */
4158 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
4159 		;
4160 	else if (!list_empty(&mddev->disks))
4161 		return -EBUSY;
4162 
4163 	if (cmd_match(buf, "none")) {
4164 		mddev->persistent = 0;
4165 		mddev->external = 0;
4166 		mddev->major_version = 0;
4167 		mddev->minor_version = 90;
4168 		return len;
4169 	}
4170 	if (strncmp(buf, "external:", 9) == 0) {
4171 		size_t namelen = len-9;
4172 		if (namelen >= sizeof(mddev->metadata_type))
4173 			namelen = sizeof(mddev->metadata_type)-1;
4174 		strncpy(mddev->metadata_type, buf+9, namelen);
4175 		mddev->metadata_type[namelen] = 0;
4176 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
4177 			mddev->metadata_type[--namelen] = 0;
4178 		mddev->persistent = 0;
4179 		mddev->external = 1;
4180 		mddev->major_version = 0;
4181 		mddev->minor_version = 90;
4182 		return len;
4183 	}
4184 	major = simple_strtoul(buf, &e, 10);
4185 	if (e==buf || *e != '.')
4186 		return -EINVAL;
4187 	buf = e+1;
4188 	minor = simple_strtoul(buf, &e, 10);
4189 	if (e==buf || (*e && *e != '\n') )
4190 		return -EINVAL;
4191 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4192 		return -ENOENT;
4193 	mddev->major_version = major;
4194 	mddev->minor_version = minor;
4195 	mddev->persistent = 1;
4196 	mddev->external = 0;
4197 	return len;
4198 }
4199 
4200 static struct md_sysfs_entry md_metadata =
4201 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4202 
4203 static ssize_t
4204 action_show(struct mddev *mddev, char *page)
4205 {
4206 	char *type = "idle";
4207 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4208 		type = "frozen";
4209 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4210 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4211 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4212 			type = "reshape";
4213 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4214 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4215 				type = "resync";
4216 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4217 				type = "check";
4218 			else
4219 				type = "repair";
4220 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4221 			type = "recover";
4222 	}
4223 	return sprintf(page, "%s\n", type);
4224 }
4225 
4226 static void reap_sync_thread(struct mddev *mddev);
4227 
4228 static ssize_t
4229 action_store(struct mddev *mddev, const char *page, size_t len)
4230 {
4231 	if (!mddev->pers || !mddev->pers->sync_request)
4232 		return -EINVAL;
4233 
4234 	if (cmd_match(page, "frozen"))
4235 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4236 	else
4237 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4238 
4239 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4240 		if (mddev->sync_thread) {
4241 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4242 			reap_sync_thread(mddev);
4243 		}
4244 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4245 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4246 		return -EBUSY;
4247 	else if (cmd_match(page, "resync"))
4248 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4249 	else if (cmd_match(page, "recover")) {
4250 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4251 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4252 	} else if (cmd_match(page, "reshape")) {
4253 		int err;
4254 		if (mddev->pers->start_reshape == NULL)
4255 			return -EINVAL;
4256 		err = mddev->pers->start_reshape(mddev);
4257 		if (err)
4258 			return err;
4259 		sysfs_notify(&mddev->kobj, NULL, "degraded");
4260 	} else {
4261 		if (cmd_match(page, "check"))
4262 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4263 		else if (!cmd_match(page, "repair"))
4264 			return -EINVAL;
4265 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4266 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4267 	}
4268 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4269 	md_wakeup_thread(mddev->thread);
4270 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4271 	return len;
4272 }
4273 
4274 static ssize_t
4275 mismatch_cnt_show(struct mddev *mddev, char *page)
4276 {
4277 	return sprintf(page, "%llu\n",
4278 		       (unsigned long long) mddev->resync_mismatches);
4279 }
4280 
4281 static struct md_sysfs_entry md_scan_mode =
4282 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4283 
4284 
4285 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4286 
4287 static ssize_t
4288 sync_min_show(struct mddev *mddev, char *page)
4289 {
4290 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
4291 		       mddev->sync_speed_min ? "local": "system");
4292 }
4293 
4294 static ssize_t
4295 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4296 {
4297 	int min;
4298 	char *e;
4299 	if (strncmp(buf, "system", 6)==0) {
4300 		mddev->sync_speed_min = 0;
4301 		return len;
4302 	}
4303 	min = simple_strtoul(buf, &e, 10);
4304 	if (buf == e || (*e && *e != '\n') || min <= 0)
4305 		return -EINVAL;
4306 	mddev->sync_speed_min = min;
4307 	return len;
4308 }
4309 
4310 static struct md_sysfs_entry md_sync_min =
4311 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4312 
4313 static ssize_t
4314 sync_max_show(struct mddev *mddev, char *page)
4315 {
4316 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
4317 		       mddev->sync_speed_max ? "local": "system");
4318 }
4319 
4320 static ssize_t
4321 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4322 {
4323 	int max;
4324 	char *e;
4325 	if (strncmp(buf, "system", 6)==0) {
4326 		mddev->sync_speed_max = 0;
4327 		return len;
4328 	}
4329 	max = simple_strtoul(buf, &e, 10);
4330 	if (buf == e || (*e && *e != '\n') || max <= 0)
4331 		return -EINVAL;
4332 	mddev->sync_speed_max = max;
4333 	return len;
4334 }
4335 
4336 static struct md_sysfs_entry md_sync_max =
4337 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4338 
4339 static ssize_t
4340 degraded_show(struct mddev *mddev, char *page)
4341 {
4342 	return sprintf(page, "%d\n", mddev->degraded);
4343 }
4344 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4345 
4346 static ssize_t
4347 sync_force_parallel_show(struct mddev *mddev, char *page)
4348 {
4349 	return sprintf(page, "%d\n", mddev->parallel_resync);
4350 }
4351 
4352 static ssize_t
4353 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4354 {
4355 	long n;
4356 
4357 	if (strict_strtol(buf, 10, &n))
4358 		return -EINVAL;
4359 
4360 	if (n != 0 && n != 1)
4361 		return -EINVAL;
4362 
4363 	mddev->parallel_resync = n;
4364 
4365 	if (mddev->sync_thread)
4366 		wake_up(&resync_wait);
4367 
4368 	return len;
4369 }
4370 
4371 /* force parallel resync, even with shared block devices */
4372 static struct md_sysfs_entry md_sync_force_parallel =
4373 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4374        sync_force_parallel_show, sync_force_parallel_store);
4375 
4376 static ssize_t
4377 sync_speed_show(struct mddev *mddev, char *page)
4378 {
4379 	unsigned long resync, dt, db;
4380 	if (mddev->curr_resync == 0)
4381 		return sprintf(page, "none\n");
4382 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4383 	dt = (jiffies - mddev->resync_mark) / HZ;
4384 	if (!dt) dt++;
4385 	db = resync - mddev->resync_mark_cnt;
4386 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4387 }
4388 
4389 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4390 
4391 static ssize_t
4392 sync_completed_show(struct mddev *mddev, char *page)
4393 {
4394 	unsigned long long max_sectors, resync;
4395 
4396 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4397 		return sprintf(page, "none\n");
4398 
4399 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4400 	    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4401 		max_sectors = mddev->resync_max_sectors;
4402 	else
4403 		max_sectors = mddev->dev_sectors;
4404 
4405 	resync = mddev->curr_resync_completed;
4406 	return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4407 }
4408 
4409 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4410 
4411 static ssize_t
4412 min_sync_show(struct mddev *mddev, char *page)
4413 {
4414 	return sprintf(page, "%llu\n",
4415 		       (unsigned long long)mddev->resync_min);
4416 }
4417 static ssize_t
4418 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4419 {
4420 	unsigned long long min;
4421 	if (strict_strtoull(buf, 10, &min))
4422 		return -EINVAL;
4423 	if (min > mddev->resync_max)
4424 		return -EINVAL;
4425 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4426 		return -EBUSY;
4427 
4428 	/* Must be a multiple of chunk_size */
4429 	if (mddev->chunk_sectors) {
4430 		sector_t temp = min;
4431 		if (sector_div(temp, mddev->chunk_sectors))
4432 			return -EINVAL;
4433 	}
4434 	mddev->resync_min = min;
4435 
4436 	return len;
4437 }
4438 
4439 static struct md_sysfs_entry md_min_sync =
4440 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4441 
4442 static ssize_t
4443 max_sync_show(struct mddev *mddev, char *page)
4444 {
4445 	if (mddev->resync_max == MaxSector)
4446 		return sprintf(page, "max\n");
4447 	else
4448 		return sprintf(page, "%llu\n",
4449 			       (unsigned long long)mddev->resync_max);
4450 }
4451 static ssize_t
4452 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4453 {
4454 	if (strncmp(buf, "max", 3) == 0)
4455 		mddev->resync_max = MaxSector;
4456 	else {
4457 		unsigned long long max;
4458 		if (strict_strtoull(buf, 10, &max))
4459 			return -EINVAL;
4460 		if (max < mddev->resync_min)
4461 			return -EINVAL;
4462 		if (max < mddev->resync_max &&
4463 		    mddev->ro == 0 &&
4464 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4465 			return -EBUSY;
4466 
4467 		/* Must be a multiple of chunk_size */
4468 		if (mddev->chunk_sectors) {
4469 			sector_t temp = max;
4470 			if (sector_div(temp, mddev->chunk_sectors))
4471 				return -EINVAL;
4472 		}
4473 		mddev->resync_max = max;
4474 	}
4475 	wake_up(&mddev->recovery_wait);
4476 	return len;
4477 }
4478 
4479 static struct md_sysfs_entry md_max_sync =
4480 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4481 
4482 static ssize_t
4483 suspend_lo_show(struct mddev *mddev, char *page)
4484 {
4485 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4486 }
4487 
4488 static ssize_t
4489 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4490 {
4491 	char *e;
4492 	unsigned long long new = simple_strtoull(buf, &e, 10);
4493 	unsigned long long old = mddev->suspend_lo;
4494 
4495 	if (mddev->pers == NULL ||
4496 	    mddev->pers->quiesce == NULL)
4497 		return -EINVAL;
4498 	if (buf == e || (*e && *e != '\n'))
4499 		return -EINVAL;
4500 
4501 	mddev->suspend_lo = new;
4502 	if (new >= old)
4503 		/* Shrinking suspended region */
4504 		mddev->pers->quiesce(mddev, 2);
4505 	else {
4506 		/* Expanding suspended region - need to wait */
4507 		mddev->pers->quiesce(mddev, 1);
4508 		mddev->pers->quiesce(mddev, 0);
4509 	}
4510 	return len;
4511 }
4512 static struct md_sysfs_entry md_suspend_lo =
4513 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4514 
4515 
4516 static ssize_t
4517 suspend_hi_show(struct mddev *mddev, char *page)
4518 {
4519 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4520 }
4521 
4522 static ssize_t
4523 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4524 {
4525 	char *e;
4526 	unsigned long long new = simple_strtoull(buf, &e, 10);
4527 	unsigned long long old = mddev->suspend_hi;
4528 
4529 	if (mddev->pers == NULL ||
4530 	    mddev->pers->quiesce == NULL)
4531 		return -EINVAL;
4532 	if (buf == e || (*e && *e != '\n'))
4533 		return -EINVAL;
4534 
4535 	mddev->suspend_hi = new;
4536 	if (new <= old)
4537 		/* Shrinking suspended region */
4538 		mddev->pers->quiesce(mddev, 2);
4539 	else {
4540 		/* Expanding suspended region - need to wait */
4541 		mddev->pers->quiesce(mddev, 1);
4542 		mddev->pers->quiesce(mddev, 0);
4543 	}
4544 	return len;
4545 }
4546 static struct md_sysfs_entry md_suspend_hi =
4547 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4548 
4549 static ssize_t
4550 reshape_position_show(struct mddev *mddev, char *page)
4551 {
4552 	if (mddev->reshape_position != MaxSector)
4553 		return sprintf(page, "%llu\n",
4554 			       (unsigned long long)mddev->reshape_position);
4555 	strcpy(page, "none\n");
4556 	return 5;
4557 }
4558 
4559 static ssize_t
4560 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4561 {
4562 	struct md_rdev *rdev;
4563 	char *e;
4564 	unsigned long long new = simple_strtoull(buf, &e, 10);
4565 	if (mddev->pers)
4566 		return -EBUSY;
4567 	if (buf == e || (*e && *e != '\n'))
4568 		return -EINVAL;
4569 	mddev->reshape_position = new;
4570 	mddev->delta_disks = 0;
4571 	mddev->reshape_backwards = 0;
4572 	mddev->new_level = mddev->level;
4573 	mddev->new_layout = mddev->layout;
4574 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4575 	rdev_for_each(rdev, mddev)
4576 		rdev->new_data_offset = rdev->data_offset;
4577 	return len;
4578 }
4579 
4580 static struct md_sysfs_entry md_reshape_position =
4581 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4582        reshape_position_store);
4583 
4584 static ssize_t
4585 reshape_direction_show(struct mddev *mddev, char *page)
4586 {
4587 	return sprintf(page, "%s\n",
4588 		       mddev->reshape_backwards ? "backwards" : "forwards");
4589 }
4590 
4591 static ssize_t
4592 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4593 {
4594 	int backwards = 0;
4595 	if (cmd_match(buf, "forwards"))
4596 		backwards = 0;
4597 	else if (cmd_match(buf, "backwards"))
4598 		backwards = 1;
4599 	else
4600 		return -EINVAL;
4601 	if (mddev->reshape_backwards == backwards)
4602 		return len;
4603 
4604 	/* check if we are allowed to change */
4605 	if (mddev->delta_disks)
4606 		return -EBUSY;
4607 
4608 	if (mddev->persistent &&
4609 	    mddev->major_version == 0)
4610 		return -EINVAL;
4611 
4612 	mddev->reshape_backwards = backwards;
4613 	return len;
4614 }
4615 
4616 static struct md_sysfs_entry md_reshape_direction =
4617 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4618        reshape_direction_store);
4619 
4620 static ssize_t
4621 array_size_show(struct mddev *mddev, char *page)
4622 {
4623 	if (mddev->external_size)
4624 		return sprintf(page, "%llu\n",
4625 			       (unsigned long long)mddev->array_sectors/2);
4626 	else
4627 		return sprintf(page, "default\n");
4628 }
4629 
4630 static ssize_t
4631 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4632 {
4633 	sector_t sectors;
4634 
4635 	if (strncmp(buf, "default", 7) == 0) {
4636 		if (mddev->pers)
4637 			sectors = mddev->pers->size(mddev, 0, 0);
4638 		else
4639 			sectors = mddev->array_sectors;
4640 
4641 		mddev->external_size = 0;
4642 	} else {
4643 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4644 			return -EINVAL;
4645 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4646 			return -E2BIG;
4647 
4648 		mddev->external_size = 1;
4649 	}
4650 
4651 	mddev->array_sectors = sectors;
4652 	if (mddev->pers) {
4653 		set_capacity(mddev->gendisk, mddev->array_sectors);
4654 		revalidate_disk(mddev->gendisk);
4655 	}
4656 	return len;
4657 }
4658 
4659 static struct md_sysfs_entry md_array_size =
4660 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4661        array_size_store);
4662 
4663 static struct attribute *md_default_attrs[] = {
4664 	&md_level.attr,
4665 	&md_layout.attr,
4666 	&md_raid_disks.attr,
4667 	&md_chunk_size.attr,
4668 	&md_size.attr,
4669 	&md_resync_start.attr,
4670 	&md_metadata.attr,
4671 	&md_new_device.attr,
4672 	&md_safe_delay.attr,
4673 	&md_array_state.attr,
4674 	&md_reshape_position.attr,
4675 	&md_reshape_direction.attr,
4676 	&md_array_size.attr,
4677 	&max_corr_read_errors.attr,
4678 	NULL,
4679 };
4680 
4681 static struct attribute *md_redundancy_attrs[] = {
4682 	&md_scan_mode.attr,
4683 	&md_mismatches.attr,
4684 	&md_sync_min.attr,
4685 	&md_sync_max.attr,
4686 	&md_sync_speed.attr,
4687 	&md_sync_force_parallel.attr,
4688 	&md_sync_completed.attr,
4689 	&md_min_sync.attr,
4690 	&md_max_sync.attr,
4691 	&md_suspend_lo.attr,
4692 	&md_suspend_hi.attr,
4693 	&md_bitmap.attr,
4694 	&md_degraded.attr,
4695 	NULL,
4696 };
4697 static struct attribute_group md_redundancy_group = {
4698 	.name = NULL,
4699 	.attrs = md_redundancy_attrs,
4700 };
4701 
4702 
4703 static ssize_t
4704 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4705 {
4706 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4707 	struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4708 	ssize_t rv;
4709 
4710 	if (!entry->show)
4711 		return -EIO;
4712 	spin_lock(&all_mddevs_lock);
4713 	if (list_empty(&mddev->all_mddevs)) {
4714 		spin_unlock(&all_mddevs_lock);
4715 		return -EBUSY;
4716 	}
4717 	mddev_get(mddev);
4718 	spin_unlock(&all_mddevs_lock);
4719 
4720 	rv = mddev_lock(mddev);
4721 	if (!rv) {
4722 		rv = entry->show(mddev, page);
4723 		mddev_unlock(mddev);
4724 	}
4725 	mddev_put(mddev);
4726 	return rv;
4727 }
4728 
4729 static ssize_t
4730 md_attr_store(struct kobject *kobj, struct attribute *attr,
4731 	      const char *page, size_t length)
4732 {
4733 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4734 	struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4735 	ssize_t rv;
4736 
4737 	if (!entry->store)
4738 		return -EIO;
4739 	if (!capable(CAP_SYS_ADMIN))
4740 		return -EACCES;
4741 	spin_lock(&all_mddevs_lock);
4742 	if (list_empty(&mddev->all_mddevs)) {
4743 		spin_unlock(&all_mddevs_lock);
4744 		return -EBUSY;
4745 	}
4746 	mddev_get(mddev);
4747 	spin_unlock(&all_mddevs_lock);
4748 	rv = mddev_lock(mddev);
4749 	if (!rv) {
4750 		rv = entry->store(mddev, page, length);
4751 		mddev_unlock(mddev);
4752 	}
4753 	mddev_put(mddev);
4754 	return rv;
4755 }
4756 
4757 static void md_free(struct kobject *ko)
4758 {
4759 	struct mddev *mddev = container_of(ko, struct mddev, kobj);
4760 
4761 	if (mddev->sysfs_state)
4762 		sysfs_put(mddev->sysfs_state);
4763 
4764 	if (mddev->gendisk) {
4765 		del_gendisk(mddev->gendisk);
4766 		put_disk(mddev->gendisk);
4767 	}
4768 	if (mddev->queue)
4769 		blk_cleanup_queue(mddev->queue);
4770 
4771 	kfree(mddev);
4772 }
4773 
4774 static const struct sysfs_ops md_sysfs_ops = {
4775 	.show	= md_attr_show,
4776 	.store	= md_attr_store,
4777 };
4778 static struct kobj_type md_ktype = {
4779 	.release	= md_free,
4780 	.sysfs_ops	= &md_sysfs_ops,
4781 	.default_attrs	= md_default_attrs,
4782 };
4783 
4784 int mdp_major = 0;
4785 
4786 static void mddev_delayed_delete(struct work_struct *ws)
4787 {
4788 	struct mddev *mddev = container_of(ws, struct mddev, del_work);
4789 
4790 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4791 	kobject_del(&mddev->kobj);
4792 	kobject_put(&mddev->kobj);
4793 }
4794 
4795 static int md_alloc(dev_t dev, char *name)
4796 {
4797 	static DEFINE_MUTEX(disks_mutex);
4798 	struct mddev *mddev = mddev_find(dev);
4799 	struct gendisk *disk;
4800 	int partitioned;
4801 	int shift;
4802 	int unit;
4803 	int error;
4804 
4805 	if (!mddev)
4806 		return -ENODEV;
4807 
4808 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4809 	shift = partitioned ? MdpMinorShift : 0;
4810 	unit = MINOR(mddev->unit) >> shift;
4811 
4812 	/* wait for any previous instance of this device to be
4813 	 * completely removed (mddev_delayed_delete).
4814 	 */
4815 	flush_workqueue(md_misc_wq);
4816 
4817 	mutex_lock(&disks_mutex);
4818 	error = -EEXIST;
4819 	if (mddev->gendisk)
4820 		goto abort;
4821 
4822 	if (name) {
4823 		/* Need to ensure that 'name' is not a duplicate.
4824 		 */
4825 		struct mddev *mddev2;
4826 		spin_lock(&all_mddevs_lock);
4827 
4828 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4829 			if (mddev2->gendisk &&
4830 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4831 				spin_unlock(&all_mddevs_lock);
4832 				goto abort;
4833 			}
4834 		spin_unlock(&all_mddevs_lock);
4835 	}
4836 
4837 	error = -ENOMEM;
4838 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4839 	if (!mddev->queue)
4840 		goto abort;
4841 	mddev->queue->queuedata = mddev;
4842 
4843 	blk_queue_make_request(mddev->queue, md_make_request);
4844 	blk_set_stacking_limits(&mddev->queue->limits);
4845 
4846 	disk = alloc_disk(1 << shift);
4847 	if (!disk) {
4848 		blk_cleanup_queue(mddev->queue);
4849 		mddev->queue = NULL;
4850 		goto abort;
4851 	}
4852 	disk->major = MAJOR(mddev->unit);
4853 	disk->first_minor = unit << shift;
4854 	if (name)
4855 		strcpy(disk->disk_name, name);
4856 	else if (partitioned)
4857 		sprintf(disk->disk_name, "md_d%d", unit);
4858 	else
4859 		sprintf(disk->disk_name, "md%d", unit);
4860 	disk->fops = &md_fops;
4861 	disk->private_data = mddev;
4862 	disk->queue = mddev->queue;
4863 	blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4864 	/* Allow extended partitions.  This makes the
4865 	 * 'mdp' device redundant, but we can't really
4866 	 * remove it now.
4867 	 */
4868 	disk->flags |= GENHD_FL_EXT_DEVT;
4869 	mddev->gendisk = disk;
4870 	/* As soon as we call add_disk(), another thread could get
4871 	 * through to md_open, so make sure it doesn't get too far
4872 	 */
4873 	mutex_lock(&mddev->open_mutex);
4874 	add_disk(disk);
4875 
4876 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4877 				     &disk_to_dev(disk)->kobj, "%s", "md");
4878 	if (error) {
4879 		/* This isn't possible, but as kobject_init_and_add is marked
4880 		 * __must_check, we must do something with the result
4881 		 */
4882 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4883 		       disk->disk_name);
4884 		error = 0;
4885 	}
4886 	if (mddev->kobj.sd &&
4887 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4888 		printk(KERN_DEBUG "pointless warning\n");
4889 	mutex_unlock(&mddev->open_mutex);
4890  abort:
4891 	mutex_unlock(&disks_mutex);
4892 	if (!error && mddev->kobj.sd) {
4893 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4894 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4895 	}
4896 	mddev_put(mddev);
4897 	return error;
4898 }
4899 
4900 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4901 {
4902 	md_alloc(dev, NULL);
4903 	return NULL;
4904 }
4905 
4906 static int add_named_array(const char *val, struct kernel_param *kp)
4907 {
4908 	/* val must be "md_*" where * is not all digits.
4909 	 * We allocate an array with a large free minor number, and
4910 	 * set the name to val.  val must not already be an active name.
4911 	 */
4912 	int len = strlen(val);
4913 	char buf[DISK_NAME_LEN];
4914 
4915 	while (len && val[len-1] == '\n')
4916 		len--;
4917 	if (len >= DISK_NAME_LEN)
4918 		return -E2BIG;
4919 	strlcpy(buf, val, len+1);
4920 	if (strncmp(buf, "md_", 3) != 0)
4921 		return -EINVAL;
4922 	return md_alloc(0, buf);
4923 }
4924 
4925 static void md_safemode_timeout(unsigned long data)
4926 {
4927 	struct mddev *mddev = (struct mddev *) data;
4928 
4929 	if (!atomic_read(&mddev->writes_pending)) {
4930 		mddev->safemode = 1;
4931 		if (mddev->external)
4932 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4933 	}
4934 	md_wakeup_thread(mddev->thread);
4935 }
4936 
4937 static int start_dirty_degraded;
4938 
4939 int md_run(struct mddev *mddev)
4940 {
4941 	int err;
4942 	struct md_rdev *rdev;
4943 	struct md_personality *pers;
4944 
4945 	if (list_empty(&mddev->disks))
4946 		/* cannot run an array with no devices.. */
4947 		return -EINVAL;
4948 
4949 	if (mddev->pers)
4950 		return -EBUSY;
4951 	/* Cannot run until previous stop completes properly */
4952 	if (mddev->sysfs_active)
4953 		return -EBUSY;
4954 
4955 	/*
4956 	 * Analyze all RAID superblock(s)
4957 	 */
4958 	if (!mddev->raid_disks) {
4959 		if (!mddev->persistent)
4960 			return -EINVAL;
4961 		analyze_sbs(mddev);
4962 	}
4963 
4964 	if (mddev->level != LEVEL_NONE)
4965 		request_module("md-level-%d", mddev->level);
4966 	else if (mddev->clevel[0])
4967 		request_module("md-%s", mddev->clevel);
4968 
4969 	/*
4970 	 * Drop all container device buffers, from now on
4971 	 * the only valid external interface is through the md
4972 	 * device.
4973 	 */
4974 	rdev_for_each(rdev, mddev) {
4975 		if (test_bit(Faulty, &rdev->flags))
4976 			continue;
4977 		sync_blockdev(rdev->bdev);
4978 		invalidate_bdev(rdev->bdev);
4979 
4980 		/* perform some consistency tests on the device.
4981 		 * We don't want the data to overlap the metadata,
4982 		 * Internal Bitmap issues have been handled elsewhere.
4983 		 */
4984 		if (rdev->meta_bdev) {
4985 			/* Nothing to check */;
4986 		} else if (rdev->data_offset < rdev->sb_start) {
4987 			if (mddev->dev_sectors &&
4988 			    rdev->data_offset + mddev->dev_sectors
4989 			    > rdev->sb_start) {
4990 				printk("md: %s: data overlaps metadata\n",
4991 				       mdname(mddev));
4992 				return -EINVAL;
4993 			}
4994 		} else {
4995 			if (rdev->sb_start + rdev->sb_size/512
4996 			    > rdev->data_offset) {
4997 				printk("md: %s: metadata overlaps data\n",
4998 				       mdname(mddev));
4999 				return -EINVAL;
5000 			}
5001 		}
5002 		sysfs_notify_dirent_safe(rdev->sysfs_state);
5003 	}
5004 
5005 	if (mddev->bio_set == NULL)
5006 		mddev->bio_set = bioset_create(BIO_POOL_SIZE,
5007 					       sizeof(struct mddev *));
5008 
5009 	spin_lock(&pers_lock);
5010 	pers = find_pers(mddev->level, mddev->clevel);
5011 	if (!pers || !try_module_get(pers->owner)) {
5012 		spin_unlock(&pers_lock);
5013 		if (mddev->level != LEVEL_NONE)
5014 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5015 			       mddev->level);
5016 		else
5017 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5018 			       mddev->clevel);
5019 		return -EINVAL;
5020 	}
5021 	mddev->pers = pers;
5022 	spin_unlock(&pers_lock);
5023 	if (mddev->level != pers->level) {
5024 		mddev->level = pers->level;
5025 		mddev->new_level = pers->level;
5026 	}
5027 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5028 
5029 	if (mddev->reshape_position != MaxSector &&
5030 	    pers->start_reshape == NULL) {
5031 		/* This personality cannot handle reshaping... */
5032 		mddev->pers = NULL;
5033 		module_put(pers->owner);
5034 		return -EINVAL;
5035 	}
5036 
5037 	if (pers->sync_request) {
5038 		/* Warn if this is a potentially silly
5039 		 * configuration.
5040 		 */
5041 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5042 		struct md_rdev *rdev2;
5043 		int warned = 0;
5044 
5045 		rdev_for_each(rdev, mddev)
5046 			rdev_for_each(rdev2, mddev) {
5047 				if (rdev < rdev2 &&
5048 				    rdev->bdev->bd_contains ==
5049 				    rdev2->bdev->bd_contains) {
5050 					printk(KERN_WARNING
5051 					       "%s: WARNING: %s appears to be"
5052 					       " on the same physical disk as"
5053 					       " %s.\n",
5054 					       mdname(mddev),
5055 					       bdevname(rdev->bdev,b),
5056 					       bdevname(rdev2->bdev,b2));
5057 					warned = 1;
5058 				}
5059 			}
5060 
5061 		if (warned)
5062 			printk(KERN_WARNING
5063 			       "True protection against single-disk"
5064 			       " failure might be compromised.\n");
5065 	}
5066 
5067 	mddev->recovery = 0;
5068 	/* may be over-ridden by personality */
5069 	mddev->resync_max_sectors = mddev->dev_sectors;
5070 
5071 	mddev->ok_start_degraded = start_dirty_degraded;
5072 
5073 	if (start_readonly && mddev->ro == 0)
5074 		mddev->ro = 2; /* read-only, but switch on first write */
5075 
5076 	err = mddev->pers->run(mddev);
5077 	if (err)
5078 		printk(KERN_ERR "md: pers->run() failed ...\n");
5079 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
5080 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5081 			  " but 'external_size' not in effect?\n", __func__);
5082 		printk(KERN_ERR
5083 		       "md: invalid array_size %llu > default size %llu\n",
5084 		       (unsigned long long)mddev->array_sectors / 2,
5085 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
5086 		err = -EINVAL;
5087 		mddev->pers->stop(mddev);
5088 	}
5089 	if (err == 0 && mddev->pers->sync_request &&
5090 	    (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5091 		err = bitmap_create(mddev);
5092 		if (err) {
5093 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5094 			       mdname(mddev), err);
5095 			mddev->pers->stop(mddev);
5096 		}
5097 	}
5098 	if (err) {
5099 		module_put(mddev->pers->owner);
5100 		mddev->pers = NULL;
5101 		bitmap_destroy(mddev);
5102 		return err;
5103 	}
5104 	if (mddev->pers->sync_request) {
5105 		if (mddev->kobj.sd &&
5106 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5107 			printk(KERN_WARNING
5108 			       "md: cannot register extra attributes for %s\n",
5109 			       mdname(mddev));
5110 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5111 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
5112 		mddev->ro = 0;
5113 
5114  	atomic_set(&mddev->writes_pending,0);
5115 	atomic_set(&mddev->max_corr_read_errors,
5116 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5117 	mddev->safemode = 0;
5118 	mddev->safemode_timer.function = md_safemode_timeout;
5119 	mddev->safemode_timer.data = (unsigned long) mddev;
5120 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5121 	mddev->in_sync = 1;
5122 	smp_wmb();
5123 	mddev->ready = 1;
5124 	rdev_for_each(rdev, mddev)
5125 		if (rdev->raid_disk >= 0)
5126 			if (sysfs_link_rdev(mddev, rdev))
5127 				/* failure here is OK */;
5128 
5129 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5130 
5131 	if (mddev->flags)
5132 		md_update_sb(mddev, 0);
5133 
5134 	md_new_event(mddev);
5135 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5136 	sysfs_notify_dirent_safe(mddev->sysfs_action);
5137 	sysfs_notify(&mddev->kobj, NULL, "degraded");
5138 	return 0;
5139 }
5140 EXPORT_SYMBOL_GPL(md_run);
5141 
5142 static int do_md_run(struct mddev *mddev)
5143 {
5144 	int err;
5145 
5146 	err = md_run(mddev);
5147 	if (err)
5148 		goto out;
5149 	err = bitmap_load(mddev);
5150 	if (err) {
5151 		bitmap_destroy(mddev);
5152 		goto out;
5153 	}
5154 
5155 	md_wakeup_thread(mddev->thread);
5156 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5157 
5158 	set_capacity(mddev->gendisk, mddev->array_sectors);
5159 	revalidate_disk(mddev->gendisk);
5160 	mddev->changed = 1;
5161 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5162 out:
5163 	return err;
5164 }
5165 
5166 static int restart_array(struct mddev *mddev)
5167 {
5168 	struct gendisk *disk = mddev->gendisk;
5169 
5170 	/* Complain if it has no devices */
5171 	if (list_empty(&mddev->disks))
5172 		return -ENXIO;
5173 	if (!mddev->pers)
5174 		return -EINVAL;
5175 	if (!mddev->ro)
5176 		return -EBUSY;
5177 	mddev->safemode = 0;
5178 	mddev->ro = 0;
5179 	set_disk_ro(disk, 0);
5180 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
5181 		mdname(mddev));
5182 	/* Kick recovery or resync if necessary */
5183 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5184 	md_wakeup_thread(mddev->thread);
5185 	md_wakeup_thread(mddev->sync_thread);
5186 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5187 	return 0;
5188 }
5189 
5190 /* similar to deny_write_access, but accounts for our holding a reference
5191  * to the file ourselves */
5192 static int deny_bitmap_write_access(struct file * file)
5193 {
5194 	struct inode *inode = file->f_mapping->host;
5195 
5196 	spin_lock(&inode->i_lock);
5197 	if (atomic_read(&inode->i_writecount) > 1) {
5198 		spin_unlock(&inode->i_lock);
5199 		return -ETXTBSY;
5200 	}
5201 	atomic_set(&inode->i_writecount, -1);
5202 	spin_unlock(&inode->i_lock);
5203 
5204 	return 0;
5205 }
5206 
5207 void restore_bitmap_write_access(struct file *file)
5208 {
5209 	struct inode *inode = file->f_mapping->host;
5210 
5211 	spin_lock(&inode->i_lock);
5212 	atomic_set(&inode->i_writecount, 1);
5213 	spin_unlock(&inode->i_lock);
5214 }
5215 
5216 static void md_clean(struct mddev *mddev)
5217 {
5218 	mddev->array_sectors = 0;
5219 	mddev->external_size = 0;
5220 	mddev->dev_sectors = 0;
5221 	mddev->raid_disks = 0;
5222 	mddev->recovery_cp = 0;
5223 	mddev->resync_min = 0;
5224 	mddev->resync_max = MaxSector;
5225 	mddev->reshape_position = MaxSector;
5226 	mddev->external = 0;
5227 	mddev->persistent = 0;
5228 	mddev->level = LEVEL_NONE;
5229 	mddev->clevel[0] = 0;
5230 	mddev->flags = 0;
5231 	mddev->ro = 0;
5232 	mddev->metadata_type[0] = 0;
5233 	mddev->chunk_sectors = 0;
5234 	mddev->ctime = mddev->utime = 0;
5235 	mddev->layout = 0;
5236 	mddev->max_disks = 0;
5237 	mddev->events = 0;
5238 	mddev->can_decrease_events = 0;
5239 	mddev->delta_disks = 0;
5240 	mddev->reshape_backwards = 0;
5241 	mddev->new_level = LEVEL_NONE;
5242 	mddev->new_layout = 0;
5243 	mddev->new_chunk_sectors = 0;
5244 	mddev->curr_resync = 0;
5245 	mddev->resync_mismatches = 0;
5246 	mddev->suspend_lo = mddev->suspend_hi = 0;
5247 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
5248 	mddev->recovery = 0;
5249 	mddev->in_sync = 0;
5250 	mddev->changed = 0;
5251 	mddev->degraded = 0;
5252 	mddev->safemode = 0;
5253 	mddev->merge_check_needed = 0;
5254 	mddev->bitmap_info.offset = 0;
5255 	mddev->bitmap_info.default_offset = 0;
5256 	mddev->bitmap_info.default_space = 0;
5257 	mddev->bitmap_info.chunksize = 0;
5258 	mddev->bitmap_info.daemon_sleep = 0;
5259 	mddev->bitmap_info.max_write_behind = 0;
5260 }
5261 
5262 static void __md_stop_writes(struct mddev *mddev)
5263 {
5264 	if (mddev->sync_thread) {
5265 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5266 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5267 		reap_sync_thread(mddev);
5268 	}
5269 
5270 	del_timer_sync(&mddev->safemode_timer);
5271 
5272 	bitmap_flush(mddev);
5273 	md_super_wait(mddev);
5274 
5275 	if (!mddev->in_sync || mddev->flags) {
5276 		/* mark array as shutdown cleanly */
5277 		mddev->in_sync = 1;
5278 		md_update_sb(mddev, 1);
5279 	}
5280 }
5281 
5282 void md_stop_writes(struct mddev *mddev)
5283 {
5284 	mddev_lock(mddev);
5285 	__md_stop_writes(mddev);
5286 	mddev_unlock(mddev);
5287 }
5288 EXPORT_SYMBOL_GPL(md_stop_writes);
5289 
5290 void md_stop(struct mddev *mddev)
5291 {
5292 	mddev->ready = 0;
5293 	mddev->pers->stop(mddev);
5294 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
5295 		mddev->to_remove = &md_redundancy_group;
5296 	module_put(mddev->pers->owner);
5297 	mddev->pers = NULL;
5298 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5299 }
5300 EXPORT_SYMBOL_GPL(md_stop);
5301 
5302 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5303 {
5304 	int err = 0;
5305 	mutex_lock(&mddev->open_mutex);
5306 	if (atomic_read(&mddev->openers) > !!bdev) {
5307 		printk("md: %s still in use.\n",mdname(mddev));
5308 		err = -EBUSY;
5309 		goto out;
5310 	}
5311 	if (bdev)
5312 		sync_blockdev(bdev);
5313 	if (mddev->pers) {
5314 		__md_stop_writes(mddev);
5315 
5316 		err  = -ENXIO;
5317 		if (mddev->ro==1)
5318 			goto out;
5319 		mddev->ro = 1;
5320 		set_disk_ro(mddev->gendisk, 1);
5321 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5322 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5323 		err = 0;
5324 	}
5325 out:
5326 	mutex_unlock(&mddev->open_mutex);
5327 	return err;
5328 }
5329 
5330 /* mode:
5331  *   0 - completely stop and dis-assemble array
5332  *   2 - stop but do not disassemble array
5333  */
5334 static int do_md_stop(struct mddev * mddev, int mode,
5335 		      struct block_device *bdev)
5336 {
5337 	struct gendisk *disk = mddev->gendisk;
5338 	struct md_rdev *rdev;
5339 
5340 	mutex_lock(&mddev->open_mutex);
5341 	if (atomic_read(&mddev->openers) > !!bdev ||
5342 	    mddev->sysfs_active) {
5343 		printk("md: %s still in use.\n",mdname(mddev));
5344 		mutex_unlock(&mddev->open_mutex);
5345 		return -EBUSY;
5346 	}
5347 	if (bdev)
5348 		/* It is possible IO was issued on some other
5349 		 * open file which was closed before we took ->open_mutex.
5350 		 * As that was not the last close __blkdev_put will not
5351 		 * have called sync_blockdev, so we must.
5352 		 */
5353 		sync_blockdev(bdev);
5354 
5355 	if (mddev->pers) {
5356 		if (mddev->ro)
5357 			set_disk_ro(disk, 0);
5358 
5359 		__md_stop_writes(mddev);
5360 		md_stop(mddev);
5361 		mddev->queue->merge_bvec_fn = NULL;
5362 		mddev->queue->backing_dev_info.congested_fn = NULL;
5363 
5364 		/* tell userspace to handle 'inactive' */
5365 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5366 
5367 		rdev_for_each(rdev, mddev)
5368 			if (rdev->raid_disk >= 0)
5369 				sysfs_unlink_rdev(mddev, rdev);
5370 
5371 		set_capacity(disk, 0);
5372 		mutex_unlock(&mddev->open_mutex);
5373 		mddev->changed = 1;
5374 		revalidate_disk(disk);
5375 
5376 		if (mddev->ro)
5377 			mddev->ro = 0;
5378 	} else
5379 		mutex_unlock(&mddev->open_mutex);
5380 	/*
5381 	 * Free resources if final stop
5382 	 */
5383 	if (mode == 0) {
5384 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5385 
5386 		bitmap_destroy(mddev);
5387 		if (mddev->bitmap_info.file) {
5388 			restore_bitmap_write_access(mddev->bitmap_info.file);
5389 			fput(mddev->bitmap_info.file);
5390 			mddev->bitmap_info.file = NULL;
5391 		}
5392 		mddev->bitmap_info.offset = 0;
5393 
5394 		export_array(mddev);
5395 
5396 		md_clean(mddev);
5397 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5398 		if (mddev->hold_active == UNTIL_STOP)
5399 			mddev->hold_active = 0;
5400 	}
5401 	blk_integrity_unregister(disk);
5402 	md_new_event(mddev);
5403 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5404 	return 0;
5405 }
5406 
5407 #ifndef MODULE
5408 static void autorun_array(struct mddev *mddev)
5409 {
5410 	struct md_rdev *rdev;
5411 	int err;
5412 
5413 	if (list_empty(&mddev->disks))
5414 		return;
5415 
5416 	printk(KERN_INFO "md: running: ");
5417 
5418 	rdev_for_each(rdev, mddev) {
5419 		char b[BDEVNAME_SIZE];
5420 		printk("<%s>", bdevname(rdev->bdev,b));
5421 	}
5422 	printk("\n");
5423 
5424 	err = do_md_run(mddev);
5425 	if (err) {
5426 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5427 		do_md_stop(mddev, 0, NULL);
5428 	}
5429 }
5430 
5431 /*
5432  * lets try to run arrays based on all disks that have arrived
5433  * until now. (those are in pending_raid_disks)
5434  *
5435  * the method: pick the first pending disk, collect all disks with
5436  * the same UUID, remove all from the pending list and put them into
5437  * the 'same_array' list. Then order this list based on superblock
5438  * update time (freshest comes first), kick out 'old' disks and
5439  * compare superblocks. If everything's fine then run it.
5440  *
5441  * If "unit" is allocated, then bump its reference count
5442  */
5443 static void autorun_devices(int part)
5444 {
5445 	struct md_rdev *rdev0, *rdev, *tmp;
5446 	struct mddev *mddev;
5447 	char b[BDEVNAME_SIZE];
5448 
5449 	printk(KERN_INFO "md: autorun ...\n");
5450 	while (!list_empty(&pending_raid_disks)) {
5451 		int unit;
5452 		dev_t dev;
5453 		LIST_HEAD(candidates);
5454 		rdev0 = list_entry(pending_raid_disks.next,
5455 					 struct md_rdev, same_set);
5456 
5457 		printk(KERN_INFO "md: considering %s ...\n",
5458 			bdevname(rdev0->bdev,b));
5459 		INIT_LIST_HEAD(&candidates);
5460 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5461 			if (super_90_load(rdev, rdev0, 0) >= 0) {
5462 				printk(KERN_INFO "md:  adding %s ...\n",
5463 					bdevname(rdev->bdev,b));
5464 				list_move(&rdev->same_set, &candidates);
5465 			}
5466 		/*
5467 		 * now we have a set of devices, with all of them having
5468 		 * mostly sane superblocks. It's time to allocate the
5469 		 * mddev.
5470 		 */
5471 		if (part) {
5472 			dev = MKDEV(mdp_major,
5473 				    rdev0->preferred_minor << MdpMinorShift);
5474 			unit = MINOR(dev) >> MdpMinorShift;
5475 		} else {
5476 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5477 			unit = MINOR(dev);
5478 		}
5479 		if (rdev0->preferred_minor != unit) {
5480 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5481 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5482 			break;
5483 		}
5484 
5485 		md_probe(dev, NULL, NULL);
5486 		mddev = mddev_find(dev);
5487 		if (!mddev || !mddev->gendisk) {
5488 			if (mddev)
5489 				mddev_put(mddev);
5490 			printk(KERN_ERR
5491 				"md: cannot allocate memory for md drive.\n");
5492 			break;
5493 		}
5494 		if (mddev_lock(mddev))
5495 			printk(KERN_WARNING "md: %s locked, cannot run\n",
5496 			       mdname(mddev));
5497 		else if (mddev->raid_disks || mddev->major_version
5498 			 || !list_empty(&mddev->disks)) {
5499 			printk(KERN_WARNING
5500 				"md: %s already running, cannot run %s\n",
5501 				mdname(mddev), bdevname(rdev0->bdev,b));
5502 			mddev_unlock(mddev);
5503 		} else {
5504 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
5505 			mddev->persistent = 1;
5506 			rdev_for_each_list(rdev, tmp, &candidates) {
5507 				list_del_init(&rdev->same_set);
5508 				if (bind_rdev_to_array(rdev, mddev))
5509 					export_rdev(rdev);
5510 			}
5511 			autorun_array(mddev);
5512 			mddev_unlock(mddev);
5513 		}
5514 		/* on success, candidates will be empty, on error
5515 		 * it won't...
5516 		 */
5517 		rdev_for_each_list(rdev, tmp, &candidates) {
5518 			list_del_init(&rdev->same_set);
5519 			export_rdev(rdev);
5520 		}
5521 		mddev_put(mddev);
5522 	}
5523 	printk(KERN_INFO "md: ... autorun DONE.\n");
5524 }
5525 #endif /* !MODULE */
5526 
5527 static int get_version(void __user * arg)
5528 {
5529 	mdu_version_t ver;
5530 
5531 	ver.major = MD_MAJOR_VERSION;
5532 	ver.minor = MD_MINOR_VERSION;
5533 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
5534 
5535 	if (copy_to_user(arg, &ver, sizeof(ver)))
5536 		return -EFAULT;
5537 
5538 	return 0;
5539 }
5540 
5541 static int get_array_info(struct mddev * mddev, void __user * arg)
5542 {
5543 	mdu_array_info_t info;
5544 	int nr,working,insync,failed,spare;
5545 	struct md_rdev *rdev;
5546 
5547 	nr=working=insync=failed=spare=0;
5548 	rdev_for_each(rdev, mddev) {
5549 		nr++;
5550 		if (test_bit(Faulty, &rdev->flags))
5551 			failed++;
5552 		else {
5553 			working++;
5554 			if (test_bit(In_sync, &rdev->flags))
5555 				insync++;
5556 			else
5557 				spare++;
5558 		}
5559 	}
5560 
5561 	info.major_version = mddev->major_version;
5562 	info.minor_version = mddev->minor_version;
5563 	info.patch_version = MD_PATCHLEVEL_VERSION;
5564 	info.ctime         = mddev->ctime;
5565 	info.level         = mddev->level;
5566 	info.size          = mddev->dev_sectors / 2;
5567 	if (info.size != mddev->dev_sectors / 2) /* overflow */
5568 		info.size = -1;
5569 	info.nr_disks      = nr;
5570 	info.raid_disks    = mddev->raid_disks;
5571 	info.md_minor      = mddev->md_minor;
5572 	info.not_persistent= !mddev->persistent;
5573 
5574 	info.utime         = mddev->utime;
5575 	info.state         = 0;
5576 	if (mddev->in_sync)
5577 		info.state = (1<<MD_SB_CLEAN);
5578 	if (mddev->bitmap && mddev->bitmap_info.offset)
5579 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5580 	info.active_disks  = insync;
5581 	info.working_disks = working;
5582 	info.failed_disks  = failed;
5583 	info.spare_disks   = spare;
5584 
5585 	info.layout        = mddev->layout;
5586 	info.chunk_size    = mddev->chunk_sectors << 9;
5587 
5588 	if (copy_to_user(arg, &info, sizeof(info)))
5589 		return -EFAULT;
5590 
5591 	return 0;
5592 }
5593 
5594 static int get_bitmap_file(struct mddev * mddev, void __user * arg)
5595 {
5596 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5597 	char *ptr, *buf = NULL;
5598 	int err = -ENOMEM;
5599 
5600 	if (md_allow_write(mddev))
5601 		file = kmalloc(sizeof(*file), GFP_NOIO);
5602 	else
5603 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5604 
5605 	if (!file)
5606 		goto out;
5607 
5608 	/* bitmap disabled, zero the first byte and copy out */
5609 	if (!mddev->bitmap || !mddev->bitmap->storage.file) {
5610 		file->pathname[0] = '\0';
5611 		goto copy_out;
5612 	}
5613 
5614 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5615 	if (!buf)
5616 		goto out;
5617 
5618 	ptr = d_path(&mddev->bitmap->storage.file->f_path,
5619 		     buf, sizeof(file->pathname));
5620 	if (IS_ERR(ptr))
5621 		goto out;
5622 
5623 	strcpy(file->pathname, ptr);
5624 
5625 copy_out:
5626 	err = 0;
5627 	if (copy_to_user(arg, file, sizeof(*file)))
5628 		err = -EFAULT;
5629 out:
5630 	kfree(buf);
5631 	kfree(file);
5632 	return err;
5633 }
5634 
5635 static int get_disk_info(struct mddev * mddev, void __user * arg)
5636 {
5637 	mdu_disk_info_t info;
5638 	struct md_rdev *rdev;
5639 
5640 	if (copy_from_user(&info, arg, sizeof(info)))
5641 		return -EFAULT;
5642 
5643 	rdev = find_rdev_nr(mddev, info.number);
5644 	if (rdev) {
5645 		info.major = MAJOR(rdev->bdev->bd_dev);
5646 		info.minor = MINOR(rdev->bdev->bd_dev);
5647 		info.raid_disk = rdev->raid_disk;
5648 		info.state = 0;
5649 		if (test_bit(Faulty, &rdev->flags))
5650 			info.state |= (1<<MD_DISK_FAULTY);
5651 		else if (test_bit(In_sync, &rdev->flags)) {
5652 			info.state |= (1<<MD_DISK_ACTIVE);
5653 			info.state |= (1<<MD_DISK_SYNC);
5654 		}
5655 		if (test_bit(WriteMostly, &rdev->flags))
5656 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5657 	} else {
5658 		info.major = info.minor = 0;
5659 		info.raid_disk = -1;
5660 		info.state = (1<<MD_DISK_REMOVED);
5661 	}
5662 
5663 	if (copy_to_user(arg, &info, sizeof(info)))
5664 		return -EFAULT;
5665 
5666 	return 0;
5667 }
5668 
5669 static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info)
5670 {
5671 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5672 	struct md_rdev *rdev;
5673 	dev_t dev = MKDEV(info->major,info->minor);
5674 
5675 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5676 		return -EOVERFLOW;
5677 
5678 	if (!mddev->raid_disks) {
5679 		int err;
5680 		/* expecting a device which has a superblock */
5681 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5682 		if (IS_ERR(rdev)) {
5683 			printk(KERN_WARNING
5684 				"md: md_import_device returned %ld\n",
5685 				PTR_ERR(rdev));
5686 			return PTR_ERR(rdev);
5687 		}
5688 		if (!list_empty(&mddev->disks)) {
5689 			struct md_rdev *rdev0
5690 				= list_entry(mddev->disks.next,
5691 					     struct md_rdev, same_set);
5692 			err = super_types[mddev->major_version]
5693 				.load_super(rdev, rdev0, mddev->minor_version);
5694 			if (err < 0) {
5695 				printk(KERN_WARNING
5696 					"md: %s has different UUID to %s\n",
5697 					bdevname(rdev->bdev,b),
5698 					bdevname(rdev0->bdev,b2));
5699 				export_rdev(rdev);
5700 				return -EINVAL;
5701 			}
5702 		}
5703 		err = bind_rdev_to_array(rdev, mddev);
5704 		if (err)
5705 			export_rdev(rdev);
5706 		return err;
5707 	}
5708 
5709 	/*
5710 	 * add_new_disk can be used once the array is assembled
5711 	 * to add "hot spares".  They must already have a superblock
5712 	 * written
5713 	 */
5714 	if (mddev->pers) {
5715 		int err;
5716 		if (!mddev->pers->hot_add_disk) {
5717 			printk(KERN_WARNING
5718 				"%s: personality does not support diskops!\n",
5719 			       mdname(mddev));
5720 			return -EINVAL;
5721 		}
5722 		if (mddev->persistent)
5723 			rdev = md_import_device(dev, mddev->major_version,
5724 						mddev->minor_version);
5725 		else
5726 			rdev = md_import_device(dev, -1, -1);
5727 		if (IS_ERR(rdev)) {
5728 			printk(KERN_WARNING
5729 				"md: md_import_device returned %ld\n",
5730 				PTR_ERR(rdev));
5731 			return PTR_ERR(rdev);
5732 		}
5733 		/* set saved_raid_disk if appropriate */
5734 		if (!mddev->persistent) {
5735 			if (info->state & (1<<MD_DISK_SYNC)  &&
5736 			    info->raid_disk < mddev->raid_disks) {
5737 				rdev->raid_disk = info->raid_disk;
5738 				set_bit(In_sync, &rdev->flags);
5739 			} else
5740 				rdev->raid_disk = -1;
5741 		} else
5742 			super_types[mddev->major_version].
5743 				validate_super(mddev, rdev);
5744 		if ((info->state & (1<<MD_DISK_SYNC)) &&
5745 		     rdev->raid_disk != info->raid_disk) {
5746 			/* This was a hot-add request, but events doesn't
5747 			 * match, so reject it.
5748 			 */
5749 			export_rdev(rdev);
5750 			return -EINVAL;
5751 		}
5752 
5753 		if (test_bit(In_sync, &rdev->flags))
5754 			rdev->saved_raid_disk = rdev->raid_disk;
5755 		else
5756 			rdev->saved_raid_disk = -1;
5757 
5758 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5759 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5760 			set_bit(WriteMostly, &rdev->flags);
5761 		else
5762 			clear_bit(WriteMostly, &rdev->flags);
5763 
5764 		rdev->raid_disk = -1;
5765 		err = bind_rdev_to_array(rdev, mddev);
5766 		if (!err && !mddev->pers->hot_remove_disk) {
5767 			/* If there is hot_add_disk but no hot_remove_disk
5768 			 * then added disks for geometry changes,
5769 			 * and should be added immediately.
5770 			 */
5771 			super_types[mddev->major_version].
5772 				validate_super(mddev, rdev);
5773 			err = mddev->pers->hot_add_disk(mddev, rdev);
5774 			if (err)
5775 				unbind_rdev_from_array(rdev);
5776 		}
5777 		if (err)
5778 			export_rdev(rdev);
5779 		else
5780 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5781 
5782 		md_update_sb(mddev, 1);
5783 		if (mddev->degraded)
5784 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5785 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5786 		if (!err)
5787 			md_new_event(mddev);
5788 		md_wakeup_thread(mddev->thread);
5789 		return err;
5790 	}
5791 
5792 	/* otherwise, add_new_disk is only allowed
5793 	 * for major_version==0 superblocks
5794 	 */
5795 	if (mddev->major_version != 0) {
5796 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5797 		       mdname(mddev));
5798 		return -EINVAL;
5799 	}
5800 
5801 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5802 		int err;
5803 		rdev = md_import_device(dev, -1, 0);
5804 		if (IS_ERR(rdev)) {
5805 			printk(KERN_WARNING
5806 				"md: error, md_import_device() returned %ld\n",
5807 				PTR_ERR(rdev));
5808 			return PTR_ERR(rdev);
5809 		}
5810 		rdev->desc_nr = info->number;
5811 		if (info->raid_disk < mddev->raid_disks)
5812 			rdev->raid_disk = info->raid_disk;
5813 		else
5814 			rdev->raid_disk = -1;
5815 
5816 		if (rdev->raid_disk < mddev->raid_disks)
5817 			if (info->state & (1<<MD_DISK_SYNC))
5818 				set_bit(In_sync, &rdev->flags);
5819 
5820 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5821 			set_bit(WriteMostly, &rdev->flags);
5822 
5823 		if (!mddev->persistent) {
5824 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5825 			rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5826 		} else
5827 			rdev->sb_start = calc_dev_sboffset(rdev);
5828 		rdev->sectors = rdev->sb_start;
5829 
5830 		err = bind_rdev_to_array(rdev, mddev);
5831 		if (err) {
5832 			export_rdev(rdev);
5833 			return err;
5834 		}
5835 	}
5836 
5837 	return 0;
5838 }
5839 
5840 static int hot_remove_disk(struct mddev * mddev, dev_t dev)
5841 {
5842 	char b[BDEVNAME_SIZE];
5843 	struct md_rdev *rdev;
5844 
5845 	rdev = find_rdev(mddev, dev);
5846 	if (!rdev)
5847 		return -ENXIO;
5848 
5849 	if (rdev->raid_disk >= 0)
5850 		goto busy;
5851 
5852 	kick_rdev_from_array(rdev);
5853 	md_update_sb(mddev, 1);
5854 	md_new_event(mddev);
5855 
5856 	return 0;
5857 busy:
5858 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5859 		bdevname(rdev->bdev,b), mdname(mddev));
5860 	return -EBUSY;
5861 }
5862 
5863 static int hot_add_disk(struct mddev * mddev, dev_t dev)
5864 {
5865 	char b[BDEVNAME_SIZE];
5866 	int err;
5867 	struct md_rdev *rdev;
5868 
5869 	if (!mddev->pers)
5870 		return -ENODEV;
5871 
5872 	if (mddev->major_version != 0) {
5873 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5874 			" version-0 superblocks.\n",
5875 			mdname(mddev));
5876 		return -EINVAL;
5877 	}
5878 	if (!mddev->pers->hot_add_disk) {
5879 		printk(KERN_WARNING
5880 			"%s: personality does not support diskops!\n",
5881 			mdname(mddev));
5882 		return -EINVAL;
5883 	}
5884 
5885 	rdev = md_import_device(dev, -1, 0);
5886 	if (IS_ERR(rdev)) {
5887 		printk(KERN_WARNING
5888 			"md: error, md_import_device() returned %ld\n",
5889 			PTR_ERR(rdev));
5890 		return -EINVAL;
5891 	}
5892 
5893 	if (mddev->persistent)
5894 		rdev->sb_start = calc_dev_sboffset(rdev);
5895 	else
5896 		rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5897 
5898 	rdev->sectors = rdev->sb_start;
5899 
5900 	if (test_bit(Faulty, &rdev->flags)) {
5901 		printk(KERN_WARNING
5902 			"md: can not hot-add faulty %s disk to %s!\n",
5903 			bdevname(rdev->bdev,b), mdname(mddev));
5904 		err = -EINVAL;
5905 		goto abort_export;
5906 	}
5907 	clear_bit(In_sync, &rdev->flags);
5908 	rdev->desc_nr = -1;
5909 	rdev->saved_raid_disk = -1;
5910 	err = bind_rdev_to_array(rdev, mddev);
5911 	if (err)
5912 		goto abort_export;
5913 
5914 	/*
5915 	 * The rest should better be atomic, we can have disk failures
5916 	 * noticed in interrupt contexts ...
5917 	 */
5918 
5919 	rdev->raid_disk = -1;
5920 
5921 	md_update_sb(mddev, 1);
5922 
5923 	/*
5924 	 * Kick recovery, maybe this spare has to be added to the
5925 	 * array immediately.
5926 	 */
5927 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5928 	md_wakeup_thread(mddev->thread);
5929 	md_new_event(mddev);
5930 	return 0;
5931 
5932 abort_export:
5933 	export_rdev(rdev);
5934 	return err;
5935 }
5936 
5937 static int set_bitmap_file(struct mddev *mddev, int fd)
5938 {
5939 	int err;
5940 
5941 	if (mddev->pers) {
5942 		if (!mddev->pers->quiesce)
5943 			return -EBUSY;
5944 		if (mddev->recovery || mddev->sync_thread)
5945 			return -EBUSY;
5946 		/* we should be able to change the bitmap.. */
5947 	}
5948 
5949 
5950 	if (fd >= 0) {
5951 		if (mddev->bitmap)
5952 			return -EEXIST; /* cannot add when bitmap is present */
5953 		mddev->bitmap_info.file = fget(fd);
5954 
5955 		if (mddev->bitmap_info.file == NULL) {
5956 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5957 			       mdname(mddev));
5958 			return -EBADF;
5959 		}
5960 
5961 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5962 		if (err) {
5963 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5964 			       mdname(mddev));
5965 			fput(mddev->bitmap_info.file);
5966 			mddev->bitmap_info.file = NULL;
5967 			return err;
5968 		}
5969 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5970 	} else if (mddev->bitmap == NULL)
5971 		return -ENOENT; /* cannot remove what isn't there */
5972 	err = 0;
5973 	if (mddev->pers) {
5974 		mddev->pers->quiesce(mddev, 1);
5975 		if (fd >= 0) {
5976 			err = bitmap_create(mddev);
5977 			if (!err)
5978 				err = bitmap_load(mddev);
5979 		}
5980 		if (fd < 0 || err) {
5981 			bitmap_destroy(mddev);
5982 			fd = -1; /* make sure to put the file */
5983 		}
5984 		mddev->pers->quiesce(mddev, 0);
5985 	}
5986 	if (fd < 0) {
5987 		if (mddev->bitmap_info.file) {
5988 			restore_bitmap_write_access(mddev->bitmap_info.file);
5989 			fput(mddev->bitmap_info.file);
5990 		}
5991 		mddev->bitmap_info.file = NULL;
5992 	}
5993 
5994 	return err;
5995 }
5996 
5997 /*
5998  * set_array_info is used two different ways
5999  * The original usage is when creating a new array.
6000  * In this usage, raid_disks is > 0 and it together with
6001  *  level, size, not_persistent,layout,chunksize determine the
6002  *  shape of the array.
6003  *  This will always create an array with a type-0.90.0 superblock.
6004  * The newer usage is when assembling an array.
6005  *  In this case raid_disks will be 0, and the major_version field is
6006  *  use to determine which style super-blocks are to be found on the devices.
6007  *  The minor and patch _version numbers are also kept incase the
6008  *  super_block handler wishes to interpret them.
6009  */
6010 static int set_array_info(struct mddev * mddev, mdu_array_info_t *info)
6011 {
6012 
6013 	if (info->raid_disks == 0) {
6014 		/* just setting version number for superblock loading */
6015 		if (info->major_version < 0 ||
6016 		    info->major_version >= ARRAY_SIZE(super_types) ||
6017 		    super_types[info->major_version].name == NULL) {
6018 			/* maybe try to auto-load a module? */
6019 			printk(KERN_INFO
6020 				"md: superblock version %d not known\n",
6021 				info->major_version);
6022 			return -EINVAL;
6023 		}
6024 		mddev->major_version = info->major_version;
6025 		mddev->minor_version = info->minor_version;
6026 		mddev->patch_version = info->patch_version;
6027 		mddev->persistent = !info->not_persistent;
6028 		/* ensure mddev_put doesn't delete this now that there
6029 		 * is some minimal configuration.
6030 		 */
6031 		mddev->ctime         = get_seconds();
6032 		return 0;
6033 	}
6034 	mddev->major_version = MD_MAJOR_VERSION;
6035 	mddev->minor_version = MD_MINOR_VERSION;
6036 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
6037 	mddev->ctime         = get_seconds();
6038 
6039 	mddev->level         = info->level;
6040 	mddev->clevel[0]     = 0;
6041 	mddev->dev_sectors   = 2 * (sector_t)info->size;
6042 	mddev->raid_disks    = info->raid_disks;
6043 	/* don't set md_minor, it is determined by which /dev/md* was
6044 	 * openned
6045 	 */
6046 	if (info->state & (1<<MD_SB_CLEAN))
6047 		mddev->recovery_cp = MaxSector;
6048 	else
6049 		mddev->recovery_cp = 0;
6050 	mddev->persistent    = ! info->not_persistent;
6051 	mddev->external	     = 0;
6052 
6053 	mddev->layout        = info->layout;
6054 	mddev->chunk_sectors = info->chunk_size >> 9;
6055 
6056 	mddev->max_disks     = MD_SB_DISKS;
6057 
6058 	if (mddev->persistent)
6059 		mddev->flags         = 0;
6060 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6061 
6062 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6063 	mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6064 	mddev->bitmap_info.offset = 0;
6065 
6066 	mddev->reshape_position = MaxSector;
6067 
6068 	/*
6069 	 * Generate a 128 bit UUID
6070 	 */
6071 	get_random_bytes(mddev->uuid, 16);
6072 
6073 	mddev->new_level = mddev->level;
6074 	mddev->new_chunk_sectors = mddev->chunk_sectors;
6075 	mddev->new_layout = mddev->layout;
6076 	mddev->delta_disks = 0;
6077 	mddev->reshape_backwards = 0;
6078 
6079 	return 0;
6080 }
6081 
6082 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6083 {
6084 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6085 
6086 	if (mddev->external_size)
6087 		return;
6088 
6089 	mddev->array_sectors = array_sectors;
6090 }
6091 EXPORT_SYMBOL(md_set_array_sectors);
6092 
6093 static int update_size(struct mddev *mddev, sector_t num_sectors)
6094 {
6095 	struct md_rdev *rdev;
6096 	int rv;
6097 	int fit = (num_sectors == 0);
6098 
6099 	if (mddev->pers->resize == NULL)
6100 		return -EINVAL;
6101 	/* The "num_sectors" is the number of sectors of each device that
6102 	 * is used.  This can only make sense for arrays with redundancy.
6103 	 * linear and raid0 always use whatever space is available. We can only
6104 	 * consider changing this number if no resync or reconstruction is
6105 	 * happening, and if the new size is acceptable. It must fit before the
6106 	 * sb_start or, if that is <data_offset, it must fit before the size
6107 	 * of each device.  If num_sectors is zero, we find the largest size
6108 	 * that fits.
6109 	 */
6110 	if (mddev->sync_thread)
6111 		return -EBUSY;
6112 
6113 	rdev_for_each(rdev, mddev) {
6114 		sector_t avail = rdev->sectors;
6115 
6116 		if (fit && (num_sectors == 0 || num_sectors > avail))
6117 			num_sectors = avail;
6118 		if (avail < num_sectors)
6119 			return -ENOSPC;
6120 	}
6121 	rv = mddev->pers->resize(mddev, num_sectors);
6122 	if (!rv)
6123 		revalidate_disk(mddev->gendisk);
6124 	return rv;
6125 }
6126 
6127 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6128 {
6129 	int rv;
6130 	struct md_rdev *rdev;
6131 	/* change the number of raid disks */
6132 	if (mddev->pers->check_reshape == NULL)
6133 		return -EINVAL;
6134 	if (raid_disks <= 0 ||
6135 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
6136 		return -EINVAL;
6137 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
6138 		return -EBUSY;
6139 
6140 	rdev_for_each(rdev, mddev) {
6141 		if (mddev->raid_disks < raid_disks &&
6142 		    rdev->data_offset < rdev->new_data_offset)
6143 			return -EINVAL;
6144 		if (mddev->raid_disks > raid_disks &&
6145 		    rdev->data_offset > rdev->new_data_offset)
6146 			return -EINVAL;
6147 	}
6148 
6149 	mddev->delta_disks = raid_disks - mddev->raid_disks;
6150 	if (mddev->delta_disks < 0)
6151 		mddev->reshape_backwards = 1;
6152 	else if (mddev->delta_disks > 0)
6153 		mddev->reshape_backwards = 0;
6154 
6155 	rv = mddev->pers->check_reshape(mddev);
6156 	if (rv < 0) {
6157 		mddev->delta_disks = 0;
6158 		mddev->reshape_backwards = 0;
6159 	}
6160 	return rv;
6161 }
6162 
6163 
6164 /*
6165  * update_array_info is used to change the configuration of an
6166  * on-line array.
6167  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6168  * fields in the info are checked against the array.
6169  * Any differences that cannot be handled will cause an error.
6170  * Normally, only one change can be managed at a time.
6171  */
6172 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6173 {
6174 	int rv = 0;
6175 	int cnt = 0;
6176 	int state = 0;
6177 
6178 	/* calculate expected state,ignoring low bits */
6179 	if (mddev->bitmap && mddev->bitmap_info.offset)
6180 		state |= (1 << MD_SB_BITMAP_PRESENT);
6181 
6182 	if (mddev->major_version != info->major_version ||
6183 	    mddev->minor_version != info->minor_version ||
6184 /*	    mddev->patch_version != info->patch_version || */
6185 	    mddev->ctime         != info->ctime         ||
6186 	    mddev->level         != info->level         ||
6187 /*	    mddev->layout        != info->layout        || */
6188 	    !mddev->persistent	 != info->not_persistent||
6189 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
6190 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6191 	    ((state^info->state) & 0xfffffe00)
6192 		)
6193 		return -EINVAL;
6194 	/* Check there is only one change */
6195 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6196 		cnt++;
6197 	if (mddev->raid_disks != info->raid_disks)
6198 		cnt++;
6199 	if (mddev->layout != info->layout)
6200 		cnt++;
6201 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6202 		cnt++;
6203 	if (cnt == 0)
6204 		return 0;
6205 	if (cnt > 1)
6206 		return -EINVAL;
6207 
6208 	if (mddev->layout != info->layout) {
6209 		/* Change layout
6210 		 * we don't need to do anything at the md level, the
6211 		 * personality will take care of it all.
6212 		 */
6213 		if (mddev->pers->check_reshape == NULL)
6214 			return -EINVAL;
6215 		else {
6216 			mddev->new_layout = info->layout;
6217 			rv = mddev->pers->check_reshape(mddev);
6218 			if (rv)
6219 				mddev->new_layout = mddev->layout;
6220 			return rv;
6221 		}
6222 	}
6223 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6224 		rv = update_size(mddev, (sector_t)info->size * 2);
6225 
6226 	if (mddev->raid_disks    != info->raid_disks)
6227 		rv = update_raid_disks(mddev, info->raid_disks);
6228 
6229 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6230 		if (mddev->pers->quiesce == NULL)
6231 			return -EINVAL;
6232 		if (mddev->recovery || mddev->sync_thread)
6233 			return -EBUSY;
6234 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6235 			/* add the bitmap */
6236 			if (mddev->bitmap)
6237 				return -EEXIST;
6238 			if (mddev->bitmap_info.default_offset == 0)
6239 				return -EINVAL;
6240 			mddev->bitmap_info.offset =
6241 				mddev->bitmap_info.default_offset;
6242 			mddev->bitmap_info.space =
6243 				mddev->bitmap_info.default_space;
6244 			mddev->pers->quiesce(mddev, 1);
6245 			rv = bitmap_create(mddev);
6246 			if (!rv)
6247 				rv = bitmap_load(mddev);
6248 			if (rv)
6249 				bitmap_destroy(mddev);
6250 			mddev->pers->quiesce(mddev, 0);
6251 		} else {
6252 			/* remove the bitmap */
6253 			if (!mddev->bitmap)
6254 				return -ENOENT;
6255 			if (mddev->bitmap->storage.file)
6256 				return -EINVAL;
6257 			mddev->pers->quiesce(mddev, 1);
6258 			bitmap_destroy(mddev);
6259 			mddev->pers->quiesce(mddev, 0);
6260 			mddev->bitmap_info.offset = 0;
6261 		}
6262 	}
6263 	md_update_sb(mddev, 1);
6264 	return rv;
6265 }
6266 
6267 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6268 {
6269 	struct md_rdev *rdev;
6270 
6271 	if (mddev->pers == NULL)
6272 		return -ENODEV;
6273 
6274 	rdev = find_rdev(mddev, dev);
6275 	if (!rdev)
6276 		return -ENODEV;
6277 
6278 	md_error(mddev, rdev);
6279 	if (!test_bit(Faulty, &rdev->flags))
6280 		return -EBUSY;
6281 	return 0;
6282 }
6283 
6284 /*
6285  * We have a problem here : there is no easy way to give a CHS
6286  * virtual geometry. We currently pretend that we have a 2 heads
6287  * 4 sectors (with a BIG number of cylinders...). This drives
6288  * dosfs just mad... ;-)
6289  */
6290 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6291 {
6292 	struct mddev *mddev = bdev->bd_disk->private_data;
6293 
6294 	geo->heads = 2;
6295 	geo->sectors = 4;
6296 	geo->cylinders = mddev->array_sectors / 8;
6297 	return 0;
6298 }
6299 
6300 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6301 			unsigned int cmd, unsigned long arg)
6302 {
6303 	int err = 0;
6304 	void __user *argp = (void __user *)arg;
6305 	struct mddev *mddev = NULL;
6306 	int ro;
6307 
6308 	switch (cmd) {
6309 	case RAID_VERSION:
6310 	case GET_ARRAY_INFO:
6311 	case GET_DISK_INFO:
6312 		break;
6313 	default:
6314 		if (!capable(CAP_SYS_ADMIN))
6315 			return -EACCES;
6316 	}
6317 
6318 	/*
6319 	 * Commands dealing with the RAID driver but not any
6320 	 * particular array:
6321 	 */
6322 	switch (cmd)
6323 	{
6324 		case RAID_VERSION:
6325 			err = get_version(argp);
6326 			goto done;
6327 
6328 		case PRINT_RAID_DEBUG:
6329 			err = 0;
6330 			md_print_devices();
6331 			goto done;
6332 
6333 #ifndef MODULE
6334 		case RAID_AUTORUN:
6335 			err = 0;
6336 			autostart_arrays(arg);
6337 			goto done;
6338 #endif
6339 		default:;
6340 	}
6341 
6342 	/*
6343 	 * Commands creating/starting a new array:
6344 	 */
6345 
6346 	mddev = bdev->bd_disk->private_data;
6347 
6348 	if (!mddev) {
6349 		BUG();
6350 		goto abort;
6351 	}
6352 
6353 	err = mddev_lock(mddev);
6354 	if (err) {
6355 		printk(KERN_INFO
6356 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
6357 			err, cmd);
6358 		goto abort;
6359 	}
6360 
6361 	switch (cmd)
6362 	{
6363 		case SET_ARRAY_INFO:
6364 			{
6365 				mdu_array_info_t info;
6366 				if (!arg)
6367 					memset(&info, 0, sizeof(info));
6368 				else if (copy_from_user(&info, argp, sizeof(info))) {
6369 					err = -EFAULT;
6370 					goto abort_unlock;
6371 				}
6372 				if (mddev->pers) {
6373 					err = update_array_info(mddev, &info);
6374 					if (err) {
6375 						printk(KERN_WARNING "md: couldn't update"
6376 						       " array info. %d\n", err);
6377 						goto abort_unlock;
6378 					}
6379 					goto done_unlock;
6380 				}
6381 				if (!list_empty(&mddev->disks)) {
6382 					printk(KERN_WARNING
6383 					       "md: array %s already has disks!\n",
6384 					       mdname(mddev));
6385 					err = -EBUSY;
6386 					goto abort_unlock;
6387 				}
6388 				if (mddev->raid_disks) {
6389 					printk(KERN_WARNING
6390 					       "md: array %s already initialised!\n",
6391 					       mdname(mddev));
6392 					err = -EBUSY;
6393 					goto abort_unlock;
6394 				}
6395 				err = set_array_info(mddev, &info);
6396 				if (err) {
6397 					printk(KERN_WARNING "md: couldn't set"
6398 					       " array info. %d\n", err);
6399 					goto abort_unlock;
6400 				}
6401 			}
6402 			goto done_unlock;
6403 
6404 		default:;
6405 	}
6406 
6407 	/*
6408 	 * Commands querying/configuring an existing array:
6409 	 */
6410 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6411 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6412 	if ((!mddev->raid_disks && !mddev->external)
6413 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6414 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6415 	    && cmd != GET_BITMAP_FILE) {
6416 		err = -ENODEV;
6417 		goto abort_unlock;
6418 	}
6419 
6420 	/*
6421 	 * Commands even a read-only array can execute:
6422 	 */
6423 	switch (cmd)
6424 	{
6425 		case GET_ARRAY_INFO:
6426 			err = get_array_info(mddev, argp);
6427 			goto done_unlock;
6428 
6429 		case GET_BITMAP_FILE:
6430 			err = get_bitmap_file(mddev, argp);
6431 			goto done_unlock;
6432 
6433 		case GET_DISK_INFO:
6434 			err = get_disk_info(mddev, argp);
6435 			goto done_unlock;
6436 
6437 		case RESTART_ARRAY_RW:
6438 			err = restart_array(mddev);
6439 			goto done_unlock;
6440 
6441 		case STOP_ARRAY:
6442 			err = do_md_stop(mddev, 0, bdev);
6443 			goto done_unlock;
6444 
6445 		case STOP_ARRAY_RO:
6446 			err = md_set_readonly(mddev, bdev);
6447 			goto done_unlock;
6448 
6449 		case BLKROSET:
6450 			if (get_user(ro, (int __user *)(arg))) {
6451 				err = -EFAULT;
6452 				goto done_unlock;
6453 			}
6454 			err = -EINVAL;
6455 
6456 			/* if the bdev is going readonly the value of mddev->ro
6457 			 * does not matter, no writes are coming
6458 			 */
6459 			if (ro)
6460 				goto done_unlock;
6461 
6462 			/* are we are already prepared for writes? */
6463 			if (mddev->ro != 1)
6464 				goto done_unlock;
6465 
6466 			/* transitioning to readauto need only happen for
6467 			 * arrays that call md_write_start
6468 			 */
6469 			if (mddev->pers) {
6470 				err = restart_array(mddev);
6471 				if (err == 0) {
6472 					mddev->ro = 2;
6473 					set_disk_ro(mddev->gendisk, 0);
6474 				}
6475 			}
6476 			goto done_unlock;
6477 	}
6478 
6479 	/*
6480 	 * The remaining ioctls are changing the state of the
6481 	 * superblock, so we do not allow them on read-only arrays.
6482 	 * However non-MD ioctls (e.g. get-size) will still come through
6483 	 * here and hit the 'default' below, so only disallow
6484 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
6485 	 */
6486 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6487 		if (mddev->ro == 2) {
6488 			mddev->ro = 0;
6489 			sysfs_notify_dirent_safe(mddev->sysfs_state);
6490 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6491 			md_wakeup_thread(mddev->thread);
6492 		} else {
6493 			err = -EROFS;
6494 			goto abort_unlock;
6495 		}
6496 	}
6497 
6498 	switch (cmd)
6499 	{
6500 		case ADD_NEW_DISK:
6501 		{
6502 			mdu_disk_info_t info;
6503 			if (copy_from_user(&info, argp, sizeof(info)))
6504 				err = -EFAULT;
6505 			else
6506 				err = add_new_disk(mddev, &info);
6507 			goto done_unlock;
6508 		}
6509 
6510 		case HOT_REMOVE_DISK:
6511 			err = hot_remove_disk(mddev, new_decode_dev(arg));
6512 			goto done_unlock;
6513 
6514 		case HOT_ADD_DISK:
6515 			err = hot_add_disk(mddev, new_decode_dev(arg));
6516 			goto done_unlock;
6517 
6518 		case SET_DISK_FAULTY:
6519 			err = set_disk_faulty(mddev, new_decode_dev(arg));
6520 			goto done_unlock;
6521 
6522 		case RUN_ARRAY:
6523 			err = do_md_run(mddev);
6524 			goto done_unlock;
6525 
6526 		case SET_BITMAP_FILE:
6527 			err = set_bitmap_file(mddev, (int)arg);
6528 			goto done_unlock;
6529 
6530 		default:
6531 			err = -EINVAL;
6532 			goto abort_unlock;
6533 	}
6534 
6535 done_unlock:
6536 abort_unlock:
6537 	if (mddev->hold_active == UNTIL_IOCTL &&
6538 	    err != -EINVAL)
6539 		mddev->hold_active = 0;
6540 	mddev_unlock(mddev);
6541 
6542 	return err;
6543 done:
6544 	if (err)
6545 		MD_BUG();
6546 abort:
6547 	return err;
6548 }
6549 #ifdef CONFIG_COMPAT
6550 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6551 		    unsigned int cmd, unsigned long arg)
6552 {
6553 	switch (cmd) {
6554 	case HOT_REMOVE_DISK:
6555 	case HOT_ADD_DISK:
6556 	case SET_DISK_FAULTY:
6557 	case SET_BITMAP_FILE:
6558 		/* These take in integer arg, do not convert */
6559 		break;
6560 	default:
6561 		arg = (unsigned long)compat_ptr(arg);
6562 		break;
6563 	}
6564 
6565 	return md_ioctl(bdev, mode, cmd, arg);
6566 }
6567 #endif /* CONFIG_COMPAT */
6568 
6569 static int md_open(struct block_device *bdev, fmode_t mode)
6570 {
6571 	/*
6572 	 * Succeed if we can lock the mddev, which confirms that
6573 	 * it isn't being stopped right now.
6574 	 */
6575 	struct mddev *mddev = mddev_find(bdev->bd_dev);
6576 	int err;
6577 
6578 	if (!mddev)
6579 		return -ENODEV;
6580 
6581 	if (mddev->gendisk != bdev->bd_disk) {
6582 		/* we are racing with mddev_put which is discarding this
6583 		 * bd_disk.
6584 		 */
6585 		mddev_put(mddev);
6586 		/* Wait until bdev->bd_disk is definitely gone */
6587 		flush_workqueue(md_misc_wq);
6588 		/* Then retry the open from the top */
6589 		return -ERESTARTSYS;
6590 	}
6591 	BUG_ON(mddev != bdev->bd_disk->private_data);
6592 
6593 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6594 		goto out;
6595 
6596 	err = 0;
6597 	atomic_inc(&mddev->openers);
6598 	mutex_unlock(&mddev->open_mutex);
6599 
6600 	check_disk_change(bdev);
6601  out:
6602 	return err;
6603 }
6604 
6605 static int md_release(struct gendisk *disk, fmode_t mode)
6606 {
6607  	struct mddev *mddev = disk->private_data;
6608 
6609 	BUG_ON(!mddev);
6610 	atomic_dec(&mddev->openers);
6611 	mddev_put(mddev);
6612 
6613 	return 0;
6614 }
6615 
6616 static int md_media_changed(struct gendisk *disk)
6617 {
6618 	struct mddev *mddev = disk->private_data;
6619 
6620 	return mddev->changed;
6621 }
6622 
6623 static int md_revalidate(struct gendisk *disk)
6624 {
6625 	struct mddev *mddev = disk->private_data;
6626 
6627 	mddev->changed = 0;
6628 	return 0;
6629 }
6630 static const struct block_device_operations md_fops =
6631 {
6632 	.owner		= THIS_MODULE,
6633 	.open		= md_open,
6634 	.release	= md_release,
6635 	.ioctl		= md_ioctl,
6636 #ifdef CONFIG_COMPAT
6637 	.compat_ioctl	= md_compat_ioctl,
6638 #endif
6639 	.getgeo		= md_getgeo,
6640 	.media_changed  = md_media_changed,
6641 	.revalidate_disk= md_revalidate,
6642 };
6643 
6644 static int md_thread(void * arg)
6645 {
6646 	struct md_thread *thread = arg;
6647 
6648 	/*
6649 	 * md_thread is a 'system-thread', it's priority should be very
6650 	 * high. We avoid resource deadlocks individually in each
6651 	 * raid personality. (RAID5 does preallocation) We also use RR and
6652 	 * the very same RT priority as kswapd, thus we will never get
6653 	 * into a priority inversion deadlock.
6654 	 *
6655 	 * we definitely have to have equal or higher priority than
6656 	 * bdflush, otherwise bdflush will deadlock if there are too
6657 	 * many dirty RAID5 blocks.
6658 	 */
6659 
6660 	allow_signal(SIGKILL);
6661 	while (!kthread_should_stop()) {
6662 
6663 		/* We need to wait INTERRUPTIBLE so that
6664 		 * we don't add to the load-average.
6665 		 * That means we need to be sure no signals are
6666 		 * pending
6667 		 */
6668 		if (signal_pending(current))
6669 			flush_signals(current);
6670 
6671 		wait_event_interruptible_timeout
6672 			(thread->wqueue,
6673 			 test_bit(THREAD_WAKEUP, &thread->flags)
6674 			 || kthread_should_stop(),
6675 			 thread->timeout);
6676 
6677 		clear_bit(THREAD_WAKEUP, &thread->flags);
6678 		if (!kthread_should_stop())
6679 			thread->run(thread->mddev);
6680 	}
6681 
6682 	return 0;
6683 }
6684 
6685 void md_wakeup_thread(struct md_thread *thread)
6686 {
6687 	if (thread) {
6688 		pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
6689 		set_bit(THREAD_WAKEUP, &thread->flags);
6690 		wake_up(&thread->wqueue);
6691 	}
6692 }
6693 
6694 struct md_thread *md_register_thread(void (*run) (struct mddev *), struct mddev *mddev,
6695 				 const char *name)
6696 {
6697 	struct md_thread *thread;
6698 
6699 	thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
6700 	if (!thread)
6701 		return NULL;
6702 
6703 	init_waitqueue_head(&thread->wqueue);
6704 
6705 	thread->run = run;
6706 	thread->mddev = mddev;
6707 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6708 	thread->tsk = kthread_run(md_thread, thread,
6709 				  "%s_%s",
6710 				  mdname(thread->mddev),
6711 				  name);
6712 	if (IS_ERR(thread->tsk)) {
6713 		kfree(thread);
6714 		return NULL;
6715 	}
6716 	return thread;
6717 }
6718 
6719 void md_unregister_thread(struct md_thread **threadp)
6720 {
6721 	struct md_thread *thread = *threadp;
6722 	if (!thread)
6723 		return;
6724 	pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6725 	/* Locking ensures that mddev_unlock does not wake_up a
6726 	 * non-existent thread
6727 	 */
6728 	spin_lock(&pers_lock);
6729 	*threadp = NULL;
6730 	spin_unlock(&pers_lock);
6731 
6732 	kthread_stop(thread->tsk);
6733 	kfree(thread);
6734 }
6735 
6736 void md_error(struct mddev *mddev, struct md_rdev *rdev)
6737 {
6738 	if (!mddev) {
6739 		MD_BUG();
6740 		return;
6741 	}
6742 
6743 	if (!rdev || test_bit(Faulty, &rdev->flags))
6744 		return;
6745 
6746 	if (!mddev->pers || !mddev->pers->error_handler)
6747 		return;
6748 	mddev->pers->error_handler(mddev,rdev);
6749 	if (mddev->degraded)
6750 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6751 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6752 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6753 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6754 	md_wakeup_thread(mddev->thread);
6755 	if (mddev->event_work.func)
6756 		queue_work(md_misc_wq, &mddev->event_work);
6757 	md_new_event_inintr(mddev);
6758 }
6759 
6760 /* seq_file implementation /proc/mdstat */
6761 
6762 static void status_unused(struct seq_file *seq)
6763 {
6764 	int i = 0;
6765 	struct md_rdev *rdev;
6766 
6767 	seq_printf(seq, "unused devices: ");
6768 
6769 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6770 		char b[BDEVNAME_SIZE];
6771 		i++;
6772 		seq_printf(seq, "%s ",
6773 			      bdevname(rdev->bdev,b));
6774 	}
6775 	if (!i)
6776 		seq_printf(seq, "<none>");
6777 
6778 	seq_printf(seq, "\n");
6779 }
6780 
6781 
6782 static void status_resync(struct seq_file *seq, struct mddev * mddev)
6783 {
6784 	sector_t max_sectors, resync, res;
6785 	unsigned long dt, db;
6786 	sector_t rt;
6787 	int scale;
6788 	unsigned int per_milli;
6789 
6790 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6791 
6792 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
6793 	    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6794 		max_sectors = mddev->resync_max_sectors;
6795 	else
6796 		max_sectors = mddev->dev_sectors;
6797 
6798 	/*
6799 	 * Should not happen.
6800 	 */
6801 	if (!max_sectors) {
6802 		MD_BUG();
6803 		return;
6804 	}
6805 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6806 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6807 	 * u32, as those are the requirements for sector_div.
6808 	 * Thus 'scale' must be at least 10
6809 	 */
6810 	scale = 10;
6811 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6812 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6813 			scale++;
6814 	}
6815 	res = (resync>>scale)*1000;
6816 	sector_div(res, (u32)((max_sectors>>scale)+1));
6817 
6818 	per_milli = res;
6819 	{
6820 		int i, x = per_milli/50, y = 20-x;
6821 		seq_printf(seq, "[");
6822 		for (i = 0; i < x; i++)
6823 			seq_printf(seq, "=");
6824 		seq_printf(seq, ">");
6825 		for (i = 0; i < y; i++)
6826 			seq_printf(seq, ".");
6827 		seq_printf(seq, "] ");
6828 	}
6829 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6830 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6831 		    "reshape" :
6832 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6833 		     "check" :
6834 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6835 		      "resync" : "recovery"))),
6836 		   per_milli/10, per_milli % 10,
6837 		   (unsigned long long) resync/2,
6838 		   (unsigned long long) max_sectors/2);
6839 
6840 	/*
6841 	 * dt: time from mark until now
6842 	 * db: blocks written from mark until now
6843 	 * rt: remaining time
6844 	 *
6845 	 * rt is a sector_t, so could be 32bit or 64bit.
6846 	 * So we divide before multiply in case it is 32bit and close
6847 	 * to the limit.
6848 	 * We scale the divisor (db) by 32 to avoid losing precision
6849 	 * near the end of resync when the number of remaining sectors
6850 	 * is close to 'db'.
6851 	 * We then divide rt by 32 after multiplying by db to compensate.
6852 	 * The '+1' avoids division by zero if db is very small.
6853 	 */
6854 	dt = ((jiffies - mddev->resync_mark) / HZ);
6855 	if (!dt) dt++;
6856 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6857 		- mddev->resync_mark_cnt;
6858 
6859 	rt = max_sectors - resync;    /* number of remaining sectors */
6860 	sector_div(rt, db/32+1);
6861 	rt *= dt;
6862 	rt >>= 5;
6863 
6864 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6865 		   ((unsigned long)rt % 60)/6);
6866 
6867 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6868 }
6869 
6870 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6871 {
6872 	struct list_head *tmp;
6873 	loff_t l = *pos;
6874 	struct mddev *mddev;
6875 
6876 	if (l >= 0x10000)
6877 		return NULL;
6878 	if (!l--)
6879 		/* header */
6880 		return (void*)1;
6881 
6882 	spin_lock(&all_mddevs_lock);
6883 	list_for_each(tmp,&all_mddevs)
6884 		if (!l--) {
6885 			mddev = list_entry(tmp, struct mddev, all_mddevs);
6886 			mddev_get(mddev);
6887 			spin_unlock(&all_mddevs_lock);
6888 			return mddev;
6889 		}
6890 	spin_unlock(&all_mddevs_lock);
6891 	if (!l--)
6892 		return (void*)2;/* tail */
6893 	return NULL;
6894 }
6895 
6896 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6897 {
6898 	struct list_head *tmp;
6899 	struct mddev *next_mddev, *mddev = v;
6900 
6901 	++*pos;
6902 	if (v == (void*)2)
6903 		return NULL;
6904 
6905 	spin_lock(&all_mddevs_lock);
6906 	if (v == (void*)1)
6907 		tmp = all_mddevs.next;
6908 	else
6909 		tmp = mddev->all_mddevs.next;
6910 	if (tmp != &all_mddevs)
6911 		next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
6912 	else {
6913 		next_mddev = (void*)2;
6914 		*pos = 0x10000;
6915 	}
6916 	spin_unlock(&all_mddevs_lock);
6917 
6918 	if (v != (void*)1)
6919 		mddev_put(mddev);
6920 	return next_mddev;
6921 
6922 }
6923 
6924 static void md_seq_stop(struct seq_file *seq, void *v)
6925 {
6926 	struct mddev *mddev = v;
6927 
6928 	if (mddev && v != (void*)1 && v != (void*)2)
6929 		mddev_put(mddev);
6930 }
6931 
6932 static int md_seq_show(struct seq_file *seq, void *v)
6933 {
6934 	struct mddev *mddev = v;
6935 	sector_t sectors;
6936 	struct md_rdev *rdev;
6937 
6938 	if (v == (void*)1) {
6939 		struct md_personality *pers;
6940 		seq_printf(seq, "Personalities : ");
6941 		spin_lock(&pers_lock);
6942 		list_for_each_entry(pers, &pers_list, list)
6943 			seq_printf(seq, "[%s] ", pers->name);
6944 
6945 		spin_unlock(&pers_lock);
6946 		seq_printf(seq, "\n");
6947 		seq->poll_event = atomic_read(&md_event_count);
6948 		return 0;
6949 	}
6950 	if (v == (void*)2) {
6951 		status_unused(seq);
6952 		return 0;
6953 	}
6954 
6955 	if (mddev_lock(mddev) < 0)
6956 		return -EINTR;
6957 
6958 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6959 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6960 						mddev->pers ? "" : "in");
6961 		if (mddev->pers) {
6962 			if (mddev->ro==1)
6963 				seq_printf(seq, " (read-only)");
6964 			if (mddev->ro==2)
6965 				seq_printf(seq, " (auto-read-only)");
6966 			seq_printf(seq, " %s", mddev->pers->name);
6967 		}
6968 
6969 		sectors = 0;
6970 		rdev_for_each(rdev, mddev) {
6971 			char b[BDEVNAME_SIZE];
6972 			seq_printf(seq, " %s[%d]",
6973 				bdevname(rdev->bdev,b), rdev->desc_nr);
6974 			if (test_bit(WriteMostly, &rdev->flags))
6975 				seq_printf(seq, "(W)");
6976 			if (test_bit(Faulty, &rdev->flags)) {
6977 				seq_printf(seq, "(F)");
6978 				continue;
6979 			}
6980 			if (rdev->raid_disk < 0)
6981 				seq_printf(seq, "(S)"); /* spare */
6982 			if (test_bit(Replacement, &rdev->flags))
6983 				seq_printf(seq, "(R)");
6984 			sectors += rdev->sectors;
6985 		}
6986 
6987 		if (!list_empty(&mddev->disks)) {
6988 			if (mddev->pers)
6989 				seq_printf(seq, "\n      %llu blocks",
6990 					   (unsigned long long)
6991 					   mddev->array_sectors / 2);
6992 			else
6993 				seq_printf(seq, "\n      %llu blocks",
6994 					   (unsigned long long)sectors / 2);
6995 		}
6996 		if (mddev->persistent) {
6997 			if (mddev->major_version != 0 ||
6998 			    mddev->minor_version != 90) {
6999 				seq_printf(seq," super %d.%d",
7000 					   mddev->major_version,
7001 					   mddev->minor_version);
7002 			}
7003 		} else if (mddev->external)
7004 			seq_printf(seq, " super external:%s",
7005 				   mddev->metadata_type);
7006 		else
7007 			seq_printf(seq, " super non-persistent");
7008 
7009 		if (mddev->pers) {
7010 			mddev->pers->status(seq, mddev);
7011 	 		seq_printf(seq, "\n      ");
7012 			if (mddev->pers->sync_request) {
7013 				if (mddev->curr_resync > 2) {
7014 					status_resync(seq, mddev);
7015 					seq_printf(seq, "\n      ");
7016 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
7017 					seq_printf(seq, "\tresync=DELAYED\n      ");
7018 				else if (mddev->recovery_cp < MaxSector)
7019 					seq_printf(seq, "\tresync=PENDING\n      ");
7020 			}
7021 		} else
7022 			seq_printf(seq, "\n       ");
7023 
7024 		bitmap_status(seq, mddev->bitmap);
7025 
7026 		seq_printf(seq, "\n");
7027 	}
7028 	mddev_unlock(mddev);
7029 
7030 	return 0;
7031 }
7032 
7033 static const struct seq_operations md_seq_ops = {
7034 	.start  = md_seq_start,
7035 	.next   = md_seq_next,
7036 	.stop   = md_seq_stop,
7037 	.show   = md_seq_show,
7038 };
7039 
7040 static int md_seq_open(struct inode *inode, struct file *file)
7041 {
7042 	struct seq_file *seq;
7043 	int error;
7044 
7045 	error = seq_open(file, &md_seq_ops);
7046 	if (error)
7047 		return error;
7048 
7049 	seq = file->private_data;
7050 	seq->poll_event = atomic_read(&md_event_count);
7051 	return error;
7052 }
7053 
7054 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7055 {
7056 	struct seq_file *seq = filp->private_data;
7057 	int mask;
7058 
7059 	poll_wait(filp, &md_event_waiters, wait);
7060 
7061 	/* always allow read */
7062 	mask = POLLIN | POLLRDNORM;
7063 
7064 	if (seq->poll_event != atomic_read(&md_event_count))
7065 		mask |= POLLERR | POLLPRI;
7066 	return mask;
7067 }
7068 
7069 static const struct file_operations md_seq_fops = {
7070 	.owner		= THIS_MODULE,
7071 	.open           = md_seq_open,
7072 	.read           = seq_read,
7073 	.llseek         = seq_lseek,
7074 	.release	= seq_release_private,
7075 	.poll		= mdstat_poll,
7076 };
7077 
7078 int register_md_personality(struct md_personality *p)
7079 {
7080 	spin_lock(&pers_lock);
7081 	list_add_tail(&p->list, &pers_list);
7082 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
7083 	spin_unlock(&pers_lock);
7084 	return 0;
7085 }
7086 
7087 int unregister_md_personality(struct md_personality *p)
7088 {
7089 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
7090 	spin_lock(&pers_lock);
7091 	list_del_init(&p->list);
7092 	spin_unlock(&pers_lock);
7093 	return 0;
7094 }
7095 
7096 static int is_mddev_idle(struct mddev *mddev, int init)
7097 {
7098 	struct md_rdev * rdev;
7099 	int idle;
7100 	int curr_events;
7101 
7102 	idle = 1;
7103 	rcu_read_lock();
7104 	rdev_for_each_rcu(rdev, mddev) {
7105 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
7106 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
7107 			      (int)part_stat_read(&disk->part0, sectors[1]) -
7108 			      atomic_read(&disk->sync_io);
7109 		/* sync IO will cause sync_io to increase before the disk_stats
7110 		 * as sync_io is counted when a request starts, and
7111 		 * disk_stats is counted when it completes.
7112 		 * So resync activity will cause curr_events to be smaller than
7113 		 * when there was no such activity.
7114 		 * non-sync IO will cause disk_stat to increase without
7115 		 * increasing sync_io so curr_events will (eventually)
7116 		 * be larger than it was before.  Once it becomes
7117 		 * substantially larger, the test below will cause
7118 		 * the array to appear non-idle, and resync will slow
7119 		 * down.
7120 		 * If there is a lot of outstanding resync activity when
7121 		 * we set last_event to curr_events, then all that activity
7122 		 * completing might cause the array to appear non-idle
7123 		 * and resync will be slowed down even though there might
7124 		 * not have been non-resync activity.  This will only
7125 		 * happen once though.  'last_events' will soon reflect
7126 		 * the state where there is little or no outstanding
7127 		 * resync requests, and further resync activity will
7128 		 * always make curr_events less than last_events.
7129 		 *
7130 		 */
7131 		if (init || curr_events - rdev->last_events > 64) {
7132 			rdev->last_events = curr_events;
7133 			idle = 0;
7134 		}
7135 	}
7136 	rcu_read_unlock();
7137 	return idle;
7138 }
7139 
7140 void md_done_sync(struct mddev *mddev, int blocks, int ok)
7141 {
7142 	/* another "blocks" (512byte) blocks have been synced */
7143 	atomic_sub(blocks, &mddev->recovery_active);
7144 	wake_up(&mddev->recovery_wait);
7145 	if (!ok) {
7146 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7147 		md_wakeup_thread(mddev->thread);
7148 		// stop recovery, signal do_sync ....
7149 	}
7150 }
7151 
7152 
7153 /* md_write_start(mddev, bi)
7154  * If we need to update some array metadata (e.g. 'active' flag
7155  * in superblock) before writing, schedule a superblock update
7156  * and wait for it to complete.
7157  */
7158 void md_write_start(struct mddev *mddev, struct bio *bi)
7159 {
7160 	int did_change = 0;
7161 	if (bio_data_dir(bi) != WRITE)
7162 		return;
7163 
7164 	BUG_ON(mddev->ro == 1);
7165 	if (mddev->ro == 2) {
7166 		/* need to switch to read/write */
7167 		mddev->ro = 0;
7168 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7169 		md_wakeup_thread(mddev->thread);
7170 		md_wakeup_thread(mddev->sync_thread);
7171 		did_change = 1;
7172 	}
7173 	atomic_inc(&mddev->writes_pending);
7174 	if (mddev->safemode == 1)
7175 		mddev->safemode = 0;
7176 	if (mddev->in_sync) {
7177 		spin_lock_irq(&mddev->write_lock);
7178 		if (mddev->in_sync) {
7179 			mddev->in_sync = 0;
7180 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7181 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
7182 			md_wakeup_thread(mddev->thread);
7183 			did_change = 1;
7184 		}
7185 		spin_unlock_irq(&mddev->write_lock);
7186 	}
7187 	if (did_change)
7188 		sysfs_notify_dirent_safe(mddev->sysfs_state);
7189 	wait_event(mddev->sb_wait,
7190 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
7191 }
7192 
7193 void md_write_end(struct mddev *mddev)
7194 {
7195 	if (atomic_dec_and_test(&mddev->writes_pending)) {
7196 		if (mddev->safemode == 2)
7197 			md_wakeup_thread(mddev->thread);
7198 		else if (mddev->safemode_delay)
7199 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
7200 	}
7201 }
7202 
7203 /* md_allow_write(mddev)
7204  * Calling this ensures that the array is marked 'active' so that writes
7205  * may proceed without blocking.  It is important to call this before
7206  * attempting a GFP_KERNEL allocation while holding the mddev lock.
7207  * Must be called with mddev_lock held.
7208  *
7209  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
7210  * is dropped, so return -EAGAIN after notifying userspace.
7211  */
7212 int md_allow_write(struct mddev *mddev)
7213 {
7214 	if (!mddev->pers)
7215 		return 0;
7216 	if (mddev->ro)
7217 		return 0;
7218 	if (!mddev->pers->sync_request)
7219 		return 0;
7220 
7221 	spin_lock_irq(&mddev->write_lock);
7222 	if (mddev->in_sync) {
7223 		mddev->in_sync = 0;
7224 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7225 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
7226 		if (mddev->safemode_delay &&
7227 		    mddev->safemode == 0)
7228 			mddev->safemode = 1;
7229 		spin_unlock_irq(&mddev->write_lock);
7230 		md_update_sb(mddev, 0);
7231 		sysfs_notify_dirent_safe(mddev->sysfs_state);
7232 	} else
7233 		spin_unlock_irq(&mddev->write_lock);
7234 
7235 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
7236 		return -EAGAIN;
7237 	else
7238 		return 0;
7239 }
7240 EXPORT_SYMBOL_GPL(md_allow_write);
7241 
7242 #define SYNC_MARKS	10
7243 #define	SYNC_MARK_STEP	(3*HZ)
7244 void md_do_sync(struct mddev *mddev)
7245 {
7246 	struct mddev *mddev2;
7247 	unsigned int currspeed = 0,
7248 		 window;
7249 	sector_t max_sectors,j, io_sectors;
7250 	unsigned long mark[SYNC_MARKS];
7251 	sector_t mark_cnt[SYNC_MARKS];
7252 	int last_mark,m;
7253 	struct list_head *tmp;
7254 	sector_t last_check;
7255 	int skipped = 0;
7256 	struct md_rdev *rdev;
7257 	char *desc;
7258 	struct blk_plug plug;
7259 
7260 	/* just incase thread restarts... */
7261 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7262 		return;
7263 	if (mddev->ro) /* never try to sync a read-only array */
7264 		return;
7265 
7266 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7267 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
7268 			desc = "data-check";
7269 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7270 			desc = "requested-resync";
7271 		else
7272 			desc = "resync";
7273 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7274 		desc = "reshape";
7275 	else
7276 		desc = "recovery";
7277 
7278 	/* we overload curr_resync somewhat here.
7279 	 * 0 == not engaged in resync at all
7280 	 * 2 == checking that there is no conflict with another sync
7281 	 * 1 == like 2, but have yielded to allow conflicting resync to
7282 	 *		commense
7283 	 * other == active in resync - this many blocks
7284 	 *
7285 	 * Before starting a resync we must have set curr_resync to
7286 	 * 2, and then checked that every "conflicting" array has curr_resync
7287 	 * less than ours.  When we find one that is the same or higher
7288 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
7289 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
7290 	 * This will mean we have to start checking from the beginning again.
7291 	 *
7292 	 */
7293 
7294 	do {
7295 		mddev->curr_resync = 2;
7296 
7297 	try_again:
7298 		if (kthread_should_stop())
7299 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7300 
7301 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7302 			goto skip;
7303 		for_each_mddev(mddev2, tmp) {
7304 			if (mddev2 == mddev)
7305 				continue;
7306 			if (!mddev->parallel_resync
7307 			&&  mddev2->curr_resync
7308 			&&  match_mddev_units(mddev, mddev2)) {
7309 				DEFINE_WAIT(wq);
7310 				if (mddev < mddev2 && mddev->curr_resync == 2) {
7311 					/* arbitrarily yield */
7312 					mddev->curr_resync = 1;
7313 					wake_up(&resync_wait);
7314 				}
7315 				if (mddev > mddev2 && mddev->curr_resync == 1)
7316 					/* no need to wait here, we can wait the next
7317 					 * time 'round when curr_resync == 2
7318 					 */
7319 					continue;
7320 				/* We need to wait 'interruptible' so as not to
7321 				 * contribute to the load average, and not to
7322 				 * be caught by 'softlockup'
7323 				 */
7324 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7325 				if (!kthread_should_stop() &&
7326 				    mddev2->curr_resync >= mddev->curr_resync) {
7327 					printk(KERN_INFO "md: delaying %s of %s"
7328 					       " until %s has finished (they"
7329 					       " share one or more physical units)\n",
7330 					       desc, mdname(mddev), mdname(mddev2));
7331 					mddev_put(mddev2);
7332 					if (signal_pending(current))
7333 						flush_signals(current);
7334 					schedule();
7335 					finish_wait(&resync_wait, &wq);
7336 					goto try_again;
7337 				}
7338 				finish_wait(&resync_wait, &wq);
7339 			}
7340 		}
7341 	} while (mddev->curr_resync < 2);
7342 
7343 	j = 0;
7344 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7345 		/* resync follows the size requested by the personality,
7346 		 * which defaults to physical size, but can be virtual size
7347 		 */
7348 		max_sectors = mddev->resync_max_sectors;
7349 		mddev->resync_mismatches = 0;
7350 		/* we don't use the checkpoint if there's a bitmap */
7351 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7352 			j = mddev->resync_min;
7353 		else if (!mddev->bitmap)
7354 			j = mddev->recovery_cp;
7355 
7356 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7357 		max_sectors = mddev->resync_max_sectors;
7358 	else {
7359 		/* recovery follows the physical size of devices */
7360 		max_sectors = mddev->dev_sectors;
7361 		j = MaxSector;
7362 		rcu_read_lock();
7363 		rdev_for_each_rcu(rdev, mddev)
7364 			if (rdev->raid_disk >= 0 &&
7365 			    !test_bit(Faulty, &rdev->flags) &&
7366 			    !test_bit(In_sync, &rdev->flags) &&
7367 			    rdev->recovery_offset < j)
7368 				j = rdev->recovery_offset;
7369 		rcu_read_unlock();
7370 	}
7371 
7372 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7373 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7374 		" %d KB/sec/disk.\n", speed_min(mddev));
7375 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7376 	       "(but not more than %d KB/sec) for %s.\n",
7377 	       speed_max(mddev), desc);
7378 
7379 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7380 
7381 	io_sectors = 0;
7382 	for (m = 0; m < SYNC_MARKS; m++) {
7383 		mark[m] = jiffies;
7384 		mark_cnt[m] = io_sectors;
7385 	}
7386 	last_mark = 0;
7387 	mddev->resync_mark = mark[last_mark];
7388 	mddev->resync_mark_cnt = mark_cnt[last_mark];
7389 
7390 	/*
7391 	 * Tune reconstruction:
7392 	 */
7393 	window = 32*(PAGE_SIZE/512);
7394 	printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7395 		window/2, (unsigned long long)max_sectors/2);
7396 
7397 	atomic_set(&mddev->recovery_active, 0);
7398 	last_check = 0;
7399 
7400 	if (j>2) {
7401 		printk(KERN_INFO
7402 		       "md: resuming %s of %s from checkpoint.\n",
7403 		       desc, mdname(mddev));
7404 		mddev->curr_resync = j;
7405 	}
7406 	mddev->curr_resync_completed = j;
7407 
7408 	blk_start_plug(&plug);
7409 	while (j < max_sectors) {
7410 		sector_t sectors;
7411 
7412 		skipped = 0;
7413 
7414 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7415 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
7416 		      (mddev->curr_resync - mddev->curr_resync_completed)
7417 		      > (max_sectors >> 4)) ||
7418 		     (j - mddev->curr_resync_completed)*2
7419 		     >= mddev->resync_max - mddev->curr_resync_completed
7420 			    )) {
7421 			/* time to update curr_resync_completed */
7422 			wait_event(mddev->recovery_wait,
7423 				   atomic_read(&mddev->recovery_active) == 0);
7424 			mddev->curr_resync_completed = j;
7425 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7426 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7427 		}
7428 
7429 		while (j >= mddev->resync_max && !kthread_should_stop()) {
7430 			/* As this condition is controlled by user-space,
7431 			 * we can block indefinitely, so use '_interruptible'
7432 			 * to avoid triggering warnings.
7433 			 */
7434 			flush_signals(current); /* just in case */
7435 			wait_event_interruptible(mddev->recovery_wait,
7436 						 mddev->resync_max > j
7437 						 || kthread_should_stop());
7438 		}
7439 
7440 		if (kthread_should_stop())
7441 			goto interrupted;
7442 
7443 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
7444 						  currspeed < speed_min(mddev));
7445 		if (sectors == 0) {
7446 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7447 			goto out;
7448 		}
7449 
7450 		if (!skipped) { /* actual IO requested */
7451 			io_sectors += sectors;
7452 			atomic_add(sectors, &mddev->recovery_active);
7453 		}
7454 
7455 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7456 			break;
7457 
7458 		j += sectors;
7459 		if (j>1) mddev->curr_resync = j;
7460 		mddev->curr_mark_cnt = io_sectors;
7461 		if (last_check == 0)
7462 			/* this is the earliest that rebuild will be
7463 			 * visible in /proc/mdstat
7464 			 */
7465 			md_new_event(mddev);
7466 
7467 		if (last_check + window > io_sectors || j == max_sectors)
7468 			continue;
7469 
7470 		last_check = io_sectors;
7471 	repeat:
7472 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
7473 			/* step marks */
7474 			int next = (last_mark+1) % SYNC_MARKS;
7475 
7476 			mddev->resync_mark = mark[next];
7477 			mddev->resync_mark_cnt = mark_cnt[next];
7478 			mark[next] = jiffies;
7479 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
7480 			last_mark = next;
7481 		}
7482 
7483 
7484 		if (kthread_should_stop())
7485 			goto interrupted;
7486 
7487 
7488 		/*
7489 		 * this loop exits only if either when we are slower than
7490 		 * the 'hard' speed limit, or the system was IO-idle for
7491 		 * a jiffy.
7492 		 * the system might be non-idle CPU-wise, but we only care
7493 		 * about not overloading the IO subsystem. (things like an
7494 		 * e2fsck being done on the RAID array should execute fast)
7495 		 */
7496 		cond_resched();
7497 
7498 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
7499 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
7500 
7501 		if (currspeed > speed_min(mddev)) {
7502 			if ((currspeed > speed_max(mddev)) ||
7503 					!is_mddev_idle(mddev, 0)) {
7504 				msleep(500);
7505 				goto repeat;
7506 			}
7507 		}
7508 	}
7509 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
7510 	/*
7511 	 * this also signals 'finished resyncing' to md_stop
7512 	 */
7513  out:
7514 	blk_finish_plug(&plug);
7515 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
7516 
7517 	/* tell personality that we are finished */
7518 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
7519 
7520 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
7521 	    mddev->curr_resync > 2) {
7522 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7523 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7524 				if (mddev->curr_resync >= mddev->recovery_cp) {
7525 					printk(KERN_INFO
7526 					       "md: checkpointing %s of %s.\n",
7527 					       desc, mdname(mddev));
7528 					mddev->recovery_cp =
7529 						mddev->curr_resync_completed;
7530 				}
7531 			} else
7532 				mddev->recovery_cp = MaxSector;
7533 		} else {
7534 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7535 				mddev->curr_resync = MaxSector;
7536 			rcu_read_lock();
7537 			rdev_for_each_rcu(rdev, mddev)
7538 				if (rdev->raid_disk >= 0 &&
7539 				    mddev->delta_disks >= 0 &&
7540 				    !test_bit(Faulty, &rdev->flags) &&
7541 				    !test_bit(In_sync, &rdev->flags) &&
7542 				    rdev->recovery_offset < mddev->curr_resync)
7543 					rdev->recovery_offset = mddev->curr_resync;
7544 			rcu_read_unlock();
7545 		}
7546 	}
7547  skip:
7548 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
7549 
7550 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7551 		/* We completed so min/max setting can be forgotten if used. */
7552 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7553 			mddev->resync_min = 0;
7554 		mddev->resync_max = MaxSector;
7555 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7556 		mddev->resync_min = mddev->curr_resync_completed;
7557 	mddev->curr_resync = 0;
7558 	wake_up(&resync_wait);
7559 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
7560 	md_wakeup_thread(mddev->thread);
7561 	return;
7562 
7563  interrupted:
7564 	/*
7565 	 * got a signal, exit.
7566 	 */
7567 	printk(KERN_INFO
7568 	       "md: md_do_sync() got signal ... exiting\n");
7569 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7570 	goto out;
7571 
7572 }
7573 EXPORT_SYMBOL_GPL(md_do_sync);
7574 
7575 static int remove_and_add_spares(struct mddev *mddev)
7576 {
7577 	struct md_rdev *rdev;
7578 	int spares = 0;
7579 	int removed = 0;
7580 
7581 	mddev->curr_resync_completed = 0;
7582 
7583 	rdev_for_each(rdev, mddev)
7584 		if (rdev->raid_disk >= 0 &&
7585 		    !test_bit(Blocked, &rdev->flags) &&
7586 		    (test_bit(Faulty, &rdev->flags) ||
7587 		     ! test_bit(In_sync, &rdev->flags)) &&
7588 		    atomic_read(&rdev->nr_pending)==0) {
7589 			if (mddev->pers->hot_remove_disk(
7590 				    mddev, rdev) == 0) {
7591 				sysfs_unlink_rdev(mddev, rdev);
7592 				rdev->raid_disk = -1;
7593 				removed++;
7594 			}
7595 		}
7596 	if (removed)
7597 		sysfs_notify(&mddev->kobj, NULL,
7598 			     "degraded");
7599 
7600 
7601 	rdev_for_each(rdev, mddev) {
7602 		if (rdev->raid_disk >= 0 &&
7603 		    !test_bit(In_sync, &rdev->flags) &&
7604 		    !test_bit(Faulty, &rdev->flags))
7605 			spares++;
7606 		if (rdev->raid_disk < 0
7607 		    && !test_bit(Faulty, &rdev->flags)) {
7608 			rdev->recovery_offset = 0;
7609 			if (mddev->pers->
7610 			    hot_add_disk(mddev, rdev) == 0) {
7611 				if (sysfs_link_rdev(mddev, rdev))
7612 					/* failure here is OK */;
7613 				spares++;
7614 				md_new_event(mddev);
7615 				set_bit(MD_CHANGE_DEVS, &mddev->flags);
7616 			}
7617 		}
7618 	}
7619 	return spares;
7620 }
7621 
7622 static void reap_sync_thread(struct mddev *mddev)
7623 {
7624 	struct md_rdev *rdev;
7625 
7626 	/* resync has finished, collect result */
7627 	md_unregister_thread(&mddev->sync_thread);
7628 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7629 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7630 		/* success...*/
7631 		/* activate any spares */
7632 		if (mddev->pers->spare_active(mddev))
7633 			sysfs_notify(&mddev->kobj, NULL,
7634 				     "degraded");
7635 	}
7636 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7637 	    mddev->pers->finish_reshape)
7638 		mddev->pers->finish_reshape(mddev);
7639 
7640 	/* If array is no-longer degraded, then any saved_raid_disk
7641 	 * information must be scrapped.  Also if any device is now
7642 	 * In_sync we must scrape the saved_raid_disk for that device
7643 	 * do the superblock for an incrementally recovered device
7644 	 * written out.
7645 	 */
7646 	rdev_for_each(rdev, mddev)
7647 		if (!mddev->degraded ||
7648 		    test_bit(In_sync, &rdev->flags))
7649 			rdev->saved_raid_disk = -1;
7650 
7651 	md_update_sb(mddev, 1);
7652 	clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7653 	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7654 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7655 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7656 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7657 	/* flag recovery needed just to double check */
7658 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7659 	sysfs_notify_dirent_safe(mddev->sysfs_action);
7660 	md_new_event(mddev);
7661 	if (mddev->event_work.func)
7662 		queue_work(md_misc_wq, &mddev->event_work);
7663 }
7664 
7665 /*
7666  * This routine is regularly called by all per-raid-array threads to
7667  * deal with generic issues like resync and super-block update.
7668  * Raid personalities that don't have a thread (linear/raid0) do not
7669  * need this as they never do any recovery or update the superblock.
7670  *
7671  * It does not do any resync itself, but rather "forks" off other threads
7672  * to do that as needed.
7673  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7674  * "->recovery" and create a thread at ->sync_thread.
7675  * When the thread finishes it sets MD_RECOVERY_DONE
7676  * and wakeups up this thread which will reap the thread and finish up.
7677  * This thread also removes any faulty devices (with nr_pending == 0).
7678  *
7679  * The overall approach is:
7680  *  1/ if the superblock needs updating, update it.
7681  *  2/ If a recovery thread is running, don't do anything else.
7682  *  3/ If recovery has finished, clean up, possibly marking spares active.
7683  *  4/ If there are any faulty devices, remove them.
7684  *  5/ If array is degraded, try to add spares devices
7685  *  6/ If array has spares or is not in-sync, start a resync thread.
7686  */
7687 void md_check_recovery(struct mddev *mddev)
7688 {
7689 	if (mddev->suspended)
7690 		return;
7691 
7692 	if (mddev->bitmap)
7693 		bitmap_daemon_work(mddev);
7694 
7695 	if (signal_pending(current)) {
7696 		if (mddev->pers->sync_request && !mddev->external) {
7697 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7698 			       mdname(mddev));
7699 			mddev->safemode = 2;
7700 		}
7701 		flush_signals(current);
7702 	}
7703 
7704 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7705 		return;
7706 	if ( ! (
7707 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7708 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7709 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7710 		(mddev->external == 0 && mddev->safemode == 1) ||
7711 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7712 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7713 		))
7714 		return;
7715 
7716 	if (mddev_trylock(mddev)) {
7717 		int spares = 0;
7718 
7719 		if (mddev->ro) {
7720 			/* Only thing we do on a ro array is remove
7721 			 * failed devices.
7722 			 */
7723 			struct md_rdev *rdev;
7724 			rdev_for_each(rdev, mddev)
7725 				if (rdev->raid_disk >= 0 &&
7726 				    !test_bit(Blocked, &rdev->flags) &&
7727 				    test_bit(Faulty, &rdev->flags) &&
7728 				    atomic_read(&rdev->nr_pending)==0) {
7729 					if (mddev->pers->hot_remove_disk(
7730 						    mddev, rdev) == 0) {
7731 						sysfs_unlink_rdev(mddev, rdev);
7732 						rdev->raid_disk = -1;
7733 					}
7734 				}
7735 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7736 			goto unlock;
7737 		}
7738 
7739 		if (!mddev->external) {
7740 			int did_change = 0;
7741 			spin_lock_irq(&mddev->write_lock);
7742 			if (mddev->safemode &&
7743 			    !atomic_read(&mddev->writes_pending) &&
7744 			    !mddev->in_sync &&
7745 			    mddev->recovery_cp == MaxSector) {
7746 				mddev->in_sync = 1;
7747 				did_change = 1;
7748 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7749 			}
7750 			if (mddev->safemode == 1)
7751 				mddev->safemode = 0;
7752 			spin_unlock_irq(&mddev->write_lock);
7753 			if (did_change)
7754 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7755 		}
7756 
7757 		if (mddev->flags)
7758 			md_update_sb(mddev, 0);
7759 
7760 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7761 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7762 			/* resync/recovery still happening */
7763 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7764 			goto unlock;
7765 		}
7766 		if (mddev->sync_thread) {
7767 			reap_sync_thread(mddev);
7768 			goto unlock;
7769 		}
7770 		/* Set RUNNING before clearing NEEDED to avoid
7771 		 * any transients in the value of "sync_action".
7772 		 */
7773 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7774 		/* Clear some bits that don't mean anything, but
7775 		 * might be left set
7776 		 */
7777 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7778 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7779 
7780 		if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7781 		    test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7782 			goto unlock;
7783 		/* no recovery is running.
7784 		 * remove any failed drives, then
7785 		 * add spares if possible.
7786 		 * Spare are also removed and re-added, to allow
7787 		 * the personality to fail the re-add.
7788 		 */
7789 
7790 		if (mddev->reshape_position != MaxSector) {
7791 			if (mddev->pers->check_reshape == NULL ||
7792 			    mddev->pers->check_reshape(mddev) != 0)
7793 				/* Cannot proceed */
7794 				goto unlock;
7795 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7796 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7797 		} else if ((spares = remove_and_add_spares(mddev))) {
7798 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7799 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7800 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7801 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7802 		} else if (mddev->recovery_cp < MaxSector) {
7803 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7804 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7805 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7806 			/* nothing to be done ... */
7807 			goto unlock;
7808 
7809 		if (mddev->pers->sync_request) {
7810 			if (spares) {
7811 				/* We are adding a device or devices to an array
7812 				 * which has the bitmap stored on all devices.
7813 				 * So make sure all bitmap pages get written
7814 				 */
7815 				bitmap_write_all(mddev->bitmap);
7816 			}
7817 			mddev->sync_thread = md_register_thread(md_do_sync,
7818 								mddev,
7819 								"resync");
7820 			if (!mddev->sync_thread) {
7821 				printk(KERN_ERR "%s: could not start resync"
7822 					" thread...\n",
7823 					mdname(mddev));
7824 				/* leave the spares where they are, it shouldn't hurt */
7825 				clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7826 				clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7827 				clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7828 				clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7829 				clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7830 			} else
7831 				md_wakeup_thread(mddev->sync_thread);
7832 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7833 			md_new_event(mddev);
7834 		}
7835 	unlock:
7836 		if (!mddev->sync_thread) {
7837 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7838 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7839 					       &mddev->recovery))
7840 				if (mddev->sysfs_action)
7841 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7842 		}
7843 		mddev_unlock(mddev);
7844 	}
7845 }
7846 
7847 void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
7848 {
7849 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7850 	wait_event_timeout(rdev->blocked_wait,
7851 			   !test_bit(Blocked, &rdev->flags) &&
7852 			   !test_bit(BlockedBadBlocks, &rdev->flags),
7853 			   msecs_to_jiffies(5000));
7854 	rdev_dec_pending(rdev, mddev);
7855 }
7856 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7857 
7858 void md_finish_reshape(struct mddev *mddev)
7859 {
7860 	/* called be personality module when reshape completes. */
7861 	struct md_rdev *rdev;
7862 
7863 	rdev_for_each(rdev, mddev) {
7864 		if (rdev->data_offset > rdev->new_data_offset)
7865 			rdev->sectors += rdev->data_offset - rdev->new_data_offset;
7866 		else
7867 			rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
7868 		rdev->data_offset = rdev->new_data_offset;
7869 	}
7870 }
7871 EXPORT_SYMBOL(md_finish_reshape);
7872 
7873 /* Bad block management.
7874  * We can record which blocks on each device are 'bad' and so just
7875  * fail those blocks, or that stripe, rather than the whole device.
7876  * Entries in the bad-block table are 64bits wide.  This comprises:
7877  * Length of bad-range, in sectors: 0-511 for lengths 1-512
7878  * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
7879  *  A 'shift' can be set so that larger blocks are tracked and
7880  *  consequently larger devices can be covered.
7881  * 'Acknowledged' flag - 1 bit. - the most significant bit.
7882  *
7883  * Locking of the bad-block table uses a seqlock so md_is_badblock
7884  * might need to retry if it is very unlucky.
7885  * We will sometimes want to check for bad blocks in a bi_end_io function,
7886  * so we use the write_seqlock_irq variant.
7887  *
7888  * When looking for a bad block we specify a range and want to
7889  * know if any block in the range is bad.  So we binary-search
7890  * to the last range that starts at-or-before the given endpoint,
7891  * (or "before the sector after the target range")
7892  * then see if it ends after the given start.
7893  * We return
7894  *  0 if there are no known bad blocks in the range
7895  *  1 if there are known bad block which are all acknowledged
7896  * -1 if there are bad blocks which have not yet been acknowledged in metadata.
7897  * plus the start/length of the first bad section we overlap.
7898  */
7899 int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
7900 		   sector_t *first_bad, int *bad_sectors)
7901 {
7902 	int hi;
7903 	int lo = 0;
7904 	u64 *p = bb->page;
7905 	int rv = 0;
7906 	sector_t target = s + sectors;
7907 	unsigned seq;
7908 
7909 	if (bb->shift > 0) {
7910 		/* round the start down, and the end up */
7911 		s >>= bb->shift;
7912 		target += (1<<bb->shift) - 1;
7913 		target >>= bb->shift;
7914 		sectors = target - s;
7915 	}
7916 	/* 'target' is now the first block after the bad range */
7917 
7918 retry:
7919 	seq = read_seqbegin(&bb->lock);
7920 
7921 	hi = bb->count;
7922 
7923 	/* Binary search between lo and hi for 'target'
7924 	 * i.e. for the last range that starts before 'target'
7925 	 */
7926 	/* INVARIANT: ranges before 'lo' and at-or-after 'hi'
7927 	 * are known not to be the last range before target.
7928 	 * VARIANT: hi-lo is the number of possible
7929 	 * ranges, and decreases until it reaches 1
7930 	 */
7931 	while (hi - lo > 1) {
7932 		int mid = (lo + hi) / 2;
7933 		sector_t a = BB_OFFSET(p[mid]);
7934 		if (a < target)
7935 			/* This could still be the one, earlier ranges
7936 			 * could not. */
7937 			lo = mid;
7938 		else
7939 			/* This and later ranges are definitely out. */
7940 			hi = mid;
7941 	}
7942 	/* 'lo' might be the last that started before target, but 'hi' isn't */
7943 	if (hi > lo) {
7944 		/* need to check all range that end after 's' to see if
7945 		 * any are unacknowledged.
7946 		 */
7947 		while (lo >= 0 &&
7948 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7949 			if (BB_OFFSET(p[lo]) < target) {
7950 				/* starts before the end, and finishes after
7951 				 * the start, so they must overlap
7952 				 */
7953 				if (rv != -1 && BB_ACK(p[lo]))
7954 					rv = 1;
7955 				else
7956 					rv = -1;
7957 				*first_bad = BB_OFFSET(p[lo]);
7958 				*bad_sectors = BB_LEN(p[lo]);
7959 			}
7960 			lo--;
7961 		}
7962 	}
7963 
7964 	if (read_seqretry(&bb->lock, seq))
7965 		goto retry;
7966 
7967 	return rv;
7968 }
7969 EXPORT_SYMBOL_GPL(md_is_badblock);
7970 
7971 /*
7972  * Add a range of bad blocks to the table.
7973  * This might extend the table, or might contract it
7974  * if two adjacent ranges can be merged.
7975  * We binary-search to find the 'insertion' point, then
7976  * decide how best to handle it.
7977  */
7978 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
7979 			    int acknowledged)
7980 {
7981 	u64 *p;
7982 	int lo, hi;
7983 	int rv = 1;
7984 
7985 	if (bb->shift < 0)
7986 		/* badblocks are disabled */
7987 		return 0;
7988 
7989 	if (bb->shift) {
7990 		/* round the start down, and the end up */
7991 		sector_t next = s + sectors;
7992 		s >>= bb->shift;
7993 		next += (1<<bb->shift) - 1;
7994 		next >>= bb->shift;
7995 		sectors = next - s;
7996 	}
7997 
7998 	write_seqlock_irq(&bb->lock);
7999 
8000 	p = bb->page;
8001 	lo = 0;
8002 	hi = bb->count;
8003 	/* Find the last range that starts at-or-before 's' */
8004 	while (hi - lo > 1) {
8005 		int mid = (lo + hi) / 2;
8006 		sector_t a = BB_OFFSET(p[mid]);
8007 		if (a <= s)
8008 			lo = mid;
8009 		else
8010 			hi = mid;
8011 	}
8012 	if (hi > lo && BB_OFFSET(p[lo]) > s)
8013 		hi = lo;
8014 
8015 	if (hi > lo) {
8016 		/* we found a range that might merge with the start
8017 		 * of our new range
8018 		 */
8019 		sector_t a = BB_OFFSET(p[lo]);
8020 		sector_t e = a + BB_LEN(p[lo]);
8021 		int ack = BB_ACK(p[lo]);
8022 		if (e >= s) {
8023 			/* Yes, we can merge with a previous range */
8024 			if (s == a && s + sectors >= e)
8025 				/* new range covers old */
8026 				ack = acknowledged;
8027 			else
8028 				ack = ack && acknowledged;
8029 
8030 			if (e < s + sectors)
8031 				e = s + sectors;
8032 			if (e - a <= BB_MAX_LEN) {
8033 				p[lo] = BB_MAKE(a, e-a, ack);
8034 				s = e;
8035 			} else {
8036 				/* does not all fit in one range,
8037 				 * make p[lo] maximal
8038 				 */
8039 				if (BB_LEN(p[lo]) != BB_MAX_LEN)
8040 					p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
8041 				s = a + BB_MAX_LEN;
8042 			}
8043 			sectors = e - s;
8044 		}
8045 	}
8046 	if (sectors && hi < bb->count) {
8047 		/* 'hi' points to the first range that starts after 's'.
8048 		 * Maybe we can merge with the start of that range */
8049 		sector_t a = BB_OFFSET(p[hi]);
8050 		sector_t e = a + BB_LEN(p[hi]);
8051 		int ack = BB_ACK(p[hi]);
8052 		if (a <= s + sectors) {
8053 			/* merging is possible */
8054 			if (e <= s + sectors) {
8055 				/* full overlap */
8056 				e = s + sectors;
8057 				ack = acknowledged;
8058 			} else
8059 				ack = ack && acknowledged;
8060 
8061 			a = s;
8062 			if (e - a <= BB_MAX_LEN) {
8063 				p[hi] = BB_MAKE(a, e-a, ack);
8064 				s = e;
8065 			} else {
8066 				p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
8067 				s = a + BB_MAX_LEN;
8068 			}
8069 			sectors = e - s;
8070 			lo = hi;
8071 			hi++;
8072 		}
8073 	}
8074 	if (sectors == 0 && hi < bb->count) {
8075 		/* we might be able to combine lo and hi */
8076 		/* Note: 's' is at the end of 'lo' */
8077 		sector_t a = BB_OFFSET(p[hi]);
8078 		int lolen = BB_LEN(p[lo]);
8079 		int hilen = BB_LEN(p[hi]);
8080 		int newlen = lolen + hilen - (s - a);
8081 		if (s >= a && newlen < BB_MAX_LEN) {
8082 			/* yes, we can combine them */
8083 			int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
8084 			p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
8085 			memmove(p + hi, p + hi + 1,
8086 				(bb->count - hi - 1) * 8);
8087 			bb->count--;
8088 		}
8089 	}
8090 	while (sectors) {
8091 		/* didn't merge (it all).
8092 		 * Need to add a range just before 'hi' */
8093 		if (bb->count >= MD_MAX_BADBLOCKS) {
8094 			/* No room for more */
8095 			rv = 0;
8096 			break;
8097 		} else {
8098 			int this_sectors = sectors;
8099 			memmove(p + hi + 1, p + hi,
8100 				(bb->count - hi) * 8);
8101 			bb->count++;
8102 
8103 			if (this_sectors > BB_MAX_LEN)
8104 				this_sectors = BB_MAX_LEN;
8105 			p[hi] = BB_MAKE(s, this_sectors, acknowledged);
8106 			sectors -= this_sectors;
8107 			s += this_sectors;
8108 		}
8109 	}
8110 
8111 	bb->changed = 1;
8112 	if (!acknowledged)
8113 		bb->unacked_exist = 1;
8114 	write_sequnlock_irq(&bb->lock);
8115 
8116 	return rv;
8117 }
8118 
8119 int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8120 		       int is_new)
8121 {
8122 	int rv;
8123 	if (is_new)
8124 		s += rdev->new_data_offset;
8125 	else
8126 		s += rdev->data_offset;
8127 	rv = md_set_badblocks(&rdev->badblocks,
8128 			      s, sectors, 0);
8129 	if (rv) {
8130 		/* Make sure they get written out promptly */
8131 		sysfs_notify_dirent_safe(rdev->sysfs_state);
8132 		set_bit(MD_CHANGE_CLEAN, &rdev->mddev->flags);
8133 		md_wakeup_thread(rdev->mddev->thread);
8134 	}
8135 	return rv;
8136 }
8137 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
8138 
8139 /*
8140  * Remove a range of bad blocks from the table.
8141  * This may involve extending the table if we spilt a region,
8142  * but it must not fail.  So if the table becomes full, we just
8143  * drop the remove request.
8144  */
8145 static int md_clear_badblocks(struct badblocks *bb, sector_t s, int sectors)
8146 {
8147 	u64 *p;
8148 	int lo, hi;
8149 	sector_t target = s + sectors;
8150 	int rv = 0;
8151 
8152 	if (bb->shift > 0) {
8153 		/* When clearing we round the start up and the end down.
8154 		 * This should not matter as the shift should align with
8155 		 * the block size and no rounding should ever be needed.
8156 		 * However it is better the think a block is bad when it
8157 		 * isn't than to think a block is not bad when it is.
8158 		 */
8159 		s += (1<<bb->shift) - 1;
8160 		s >>= bb->shift;
8161 		target >>= bb->shift;
8162 		sectors = target - s;
8163 	}
8164 
8165 	write_seqlock_irq(&bb->lock);
8166 
8167 	p = bb->page;
8168 	lo = 0;
8169 	hi = bb->count;
8170 	/* Find the last range that starts before 'target' */
8171 	while (hi - lo > 1) {
8172 		int mid = (lo + hi) / 2;
8173 		sector_t a = BB_OFFSET(p[mid]);
8174 		if (a < target)
8175 			lo = mid;
8176 		else
8177 			hi = mid;
8178 	}
8179 	if (hi > lo) {
8180 		/* p[lo] is the last range that could overlap the
8181 		 * current range.  Earlier ranges could also overlap,
8182 		 * but only this one can overlap the end of the range.
8183 		 */
8184 		if (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) {
8185 			/* Partial overlap, leave the tail of this range */
8186 			int ack = BB_ACK(p[lo]);
8187 			sector_t a = BB_OFFSET(p[lo]);
8188 			sector_t end = a + BB_LEN(p[lo]);
8189 
8190 			if (a < s) {
8191 				/* we need to split this range */
8192 				if (bb->count >= MD_MAX_BADBLOCKS) {
8193 					rv = 0;
8194 					goto out;
8195 				}
8196 				memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
8197 				bb->count++;
8198 				p[lo] = BB_MAKE(a, s-a, ack);
8199 				lo++;
8200 			}
8201 			p[lo] = BB_MAKE(target, end - target, ack);
8202 			/* there is no longer an overlap */
8203 			hi = lo;
8204 			lo--;
8205 		}
8206 		while (lo >= 0 &&
8207 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
8208 			/* This range does overlap */
8209 			if (BB_OFFSET(p[lo]) < s) {
8210 				/* Keep the early parts of this range. */
8211 				int ack = BB_ACK(p[lo]);
8212 				sector_t start = BB_OFFSET(p[lo]);
8213 				p[lo] = BB_MAKE(start, s - start, ack);
8214 				/* now low doesn't overlap, so.. */
8215 				break;
8216 			}
8217 			lo--;
8218 		}
8219 		/* 'lo' is strictly before, 'hi' is strictly after,
8220 		 * anything between needs to be discarded
8221 		 */
8222 		if (hi - lo > 1) {
8223 			memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
8224 			bb->count -= (hi - lo - 1);
8225 		}
8226 	}
8227 
8228 	bb->changed = 1;
8229 out:
8230 	write_sequnlock_irq(&bb->lock);
8231 	return rv;
8232 }
8233 
8234 int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8235 			 int is_new)
8236 {
8237 	if (is_new)
8238 		s += rdev->new_data_offset;
8239 	else
8240 		s += rdev->data_offset;
8241 	return md_clear_badblocks(&rdev->badblocks,
8242 				  s, sectors);
8243 }
8244 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
8245 
8246 /*
8247  * Acknowledge all bad blocks in a list.
8248  * This only succeeds if ->changed is clear.  It is used by
8249  * in-kernel metadata updates
8250  */
8251 void md_ack_all_badblocks(struct badblocks *bb)
8252 {
8253 	if (bb->page == NULL || bb->changed)
8254 		/* no point even trying */
8255 		return;
8256 	write_seqlock_irq(&bb->lock);
8257 
8258 	if (bb->changed == 0 && bb->unacked_exist) {
8259 		u64 *p = bb->page;
8260 		int i;
8261 		for (i = 0; i < bb->count ; i++) {
8262 			if (!BB_ACK(p[i])) {
8263 				sector_t start = BB_OFFSET(p[i]);
8264 				int len = BB_LEN(p[i]);
8265 				p[i] = BB_MAKE(start, len, 1);
8266 			}
8267 		}
8268 		bb->unacked_exist = 0;
8269 	}
8270 	write_sequnlock_irq(&bb->lock);
8271 }
8272 EXPORT_SYMBOL_GPL(md_ack_all_badblocks);
8273 
8274 /* sysfs access to bad-blocks list.
8275  * We present two files.
8276  * 'bad-blocks' lists sector numbers and lengths of ranges that
8277  *    are recorded as bad.  The list is truncated to fit within
8278  *    the one-page limit of sysfs.
8279  *    Writing "sector length" to this file adds an acknowledged
8280  *    bad block list.
8281  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
8282  *    been acknowledged.  Writing to this file adds bad blocks
8283  *    without acknowledging them.  This is largely for testing.
8284  */
8285 
8286 static ssize_t
8287 badblocks_show(struct badblocks *bb, char *page, int unack)
8288 {
8289 	size_t len;
8290 	int i;
8291 	u64 *p = bb->page;
8292 	unsigned seq;
8293 
8294 	if (bb->shift < 0)
8295 		return 0;
8296 
8297 retry:
8298 	seq = read_seqbegin(&bb->lock);
8299 
8300 	len = 0;
8301 	i = 0;
8302 
8303 	while (len < PAGE_SIZE && i < bb->count) {
8304 		sector_t s = BB_OFFSET(p[i]);
8305 		unsigned int length = BB_LEN(p[i]);
8306 		int ack = BB_ACK(p[i]);
8307 		i++;
8308 
8309 		if (unack && ack)
8310 			continue;
8311 
8312 		len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
8313 				(unsigned long long)s << bb->shift,
8314 				length << bb->shift);
8315 	}
8316 	if (unack && len == 0)
8317 		bb->unacked_exist = 0;
8318 
8319 	if (read_seqretry(&bb->lock, seq))
8320 		goto retry;
8321 
8322 	return len;
8323 }
8324 
8325 #define DO_DEBUG 1
8326 
8327 static ssize_t
8328 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack)
8329 {
8330 	unsigned long long sector;
8331 	int length;
8332 	char newline;
8333 #ifdef DO_DEBUG
8334 	/* Allow clearing via sysfs *only* for testing/debugging.
8335 	 * Normally only a successful write may clear a badblock
8336 	 */
8337 	int clear = 0;
8338 	if (page[0] == '-') {
8339 		clear = 1;
8340 		page++;
8341 	}
8342 #endif /* DO_DEBUG */
8343 
8344 	switch (sscanf(page, "%llu %d%c", &sector, &length, &newline)) {
8345 	case 3:
8346 		if (newline != '\n')
8347 			return -EINVAL;
8348 	case 2:
8349 		if (length <= 0)
8350 			return -EINVAL;
8351 		break;
8352 	default:
8353 		return -EINVAL;
8354 	}
8355 
8356 #ifdef DO_DEBUG
8357 	if (clear) {
8358 		md_clear_badblocks(bb, sector, length);
8359 		return len;
8360 	}
8361 #endif /* DO_DEBUG */
8362 	if (md_set_badblocks(bb, sector, length, !unack))
8363 		return len;
8364 	else
8365 		return -ENOSPC;
8366 }
8367 
8368 static int md_notify_reboot(struct notifier_block *this,
8369 			    unsigned long code, void *x)
8370 {
8371 	struct list_head *tmp;
8372 	struct mddev *mddev;
8373 	int need_delay = 0;
8374 
8375 	for_each_mddev(mddev, tmp) {
8376 		if (mddev_trylock(mddev)) {
8377 			if (mddev->pers)
8378 				__md_stop_writes(mddev);
8379 			mddev->safemode = 2;
8380 			mddev_unlock(mddev);
8381 		}
8382 		need_delay = 1;
8383 	}
8384 	/*
8385 	 * certain more exotic SCSI devices are known to be
8386 	 * volatile wrt too early system reboots. While the
8387 	 * right place to handle this issue is the given
8388 	 * driver, we do want to have a safe RAID driver ...
8389 	 */
8390 	if (need_delay)
8391 		mdelay(1000*1);
8392 
8393 	return NOTIFY_DONE;
8394 }
8395 
8396 static struct notifier_block md_notifier = {
8397 	.notifier_call	= md_notify_reboot,
8398 	.next		= NULL,
8399 	.priority	= INT_MAX, /* before any real devices */
8400 };
8401 
8402 static void md_geninit(void)
8403 {
8404 	pr_debug("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
8405 
8406 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
8407 }
8408 
8409 static int __init md_init(void)
8410 {
8411 	int ret = -ENOMEM;
8412 
8413 	md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
8414 	if (!md_wq)
8415 		goto err_wq;
8416 
8417 	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
8418 	if (!md_misc_wq)
8419 		goto err_misc_wq;
8420 
8421 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
8422 		goto err_md;
8423 
8424 	if ((ret = register_blkdev(0, "mdp")) < 0)
8425 		goto err_mdp;
8426 	mdp_major = ret;
8427 
8428 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
8429 			    md_probe, NULL, NULL);
8430 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
8431 			    md_probe, NULL, NULL);
8432 
8433 	register_reboot_notifier(&md_notifier);
8434 	raid_table_header = register_sysctl_table(raid_root_table);
8435 
8436 	md_geninit();
8437 	return 0;
8438 
8439 err_mdp:
8440 	unregister_blkdev(MD_MAJOR, "md");
8441 err_md:
8442 	destroy_workqueue(md_misc_wq);
8443 err_misc_wq:
8444 	destroy_workqueue(md_wq);
8445 err_wq:
8446 	return ret;
8447 }
8448 
8449 #ifndef MODULE
8450 
8451 /*
8452  * Searches all registered partitions for autorun RAID arrays
8453  * at boot time.
8454  */
8455 
8456 static LIST_HEAD(all_detected_devices);
8457 struct detected_devices_node {
8458 	struct list_head list;
8459 	dev_t dev;
8460 };
8461 
8462 void md_autodetect_dev(dev_t dev)
8463 {
8464 	struct detected_devices_node *node_detected_dev;
8465 
8466 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
8467 	if (node_detected_dev) {
8468 		node_detected_dev->dev = dev;
8469 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
8470 	} else {
8471 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
8472 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
8473 	}
8474 }
8475 
8476 
8477 static void autostart_arrays(int part)
8478 {
8479 	struct md_rdev *rdev;
8480 	struct detected_devices_node *node_detected_dev;
8481 	dev_t dev;
8482 	int i_scanned, i_passed;
8483 
8484 	i_scanned = 0;
8485 	i_passed = 0;
8486 
8487 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
8488 
8489 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
8490 		i_scanned++;
8491 		node_detected_dev = list_entry(all_detected_devices.next,
8492 					struct detected_devices_node, list);
8493 		list_del(&node_detected_dev->list);
8494 		dev = node_detected_dev->dev;
8495 		kfree(node_detected_dev);
8496 		rdev = md_import_device(dev,0, 90);
8497 		if (IS_ERR(rdev))
8498 			continue;
8499 
8500 		if (test_bit(Faulty, &rdev->flags)) {
8501 			MD_BUG();
8502 			continue;
8503 		}
8504 		set_bit(AutoDetected, &rdev->flags);
8505 		list_add(&rdev->same_set, &pending_raid_disks);
8506 		i_passed++;
8507 	}
8508 
8509 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
8510 						i_scanned, i_passed);
8511 
8512 	autorun_devices(part);
8513 }
8514 
8515 #endif /* !MODULE */
8516 
8517 static __exit void md_exit(void)
8518 {
8519 	struct mddev *mddev;
8520 	struct list_head *tmp;
8521 
8522 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
8523 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
8524 
8525 	unregister_blkdev(MD_MAJOR,"md");
8526 	unregister_blkdev(mdp_major, "mdp");
8527 	unregister_reboot_notifier(&md_notifier);
8528 	unregister_sysctl_table(raid_table_header);
8529 	remove_proc_entry("mdstat", NULL);
8530 	for_each_mddev(mddev, tmp) {
8531 		export_array(mddev);
8532 		mddev->hold_active = 0;
8533 	}
8534 	destroy_workqueue(md_misc_wq);
8535 	destroy_workqueue(md_wq);
8536 }
8537 
8538 subsys_initcall(md_init);
8539 module_exit(md_exit)
8540 
8541 static int get_ro(char *buffer, struct kernel_param *kp)
8542 {
8543 	return sprintf(buffer, "%d", start_readonly);
8544 }
8545 static int set_ro(const char *val, struct kernel_param *kp)
8546 {
8547 	char *e;
8548 	int num = simple_strtoul(val, &e, 10);
8549 	if (*val && (*e == '\0' || *e == '\n')) {
8550 		start_readonly = num;
8551 		return 0;
8552 	}
8553 	return -EINVAL;
8554 }
8555 
8556 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
8557 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
8558 
8559 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
8560 
8561 EXPORT_SYMBOL(register_md_personality);
8562 EXPORT_SYMBOL(unregister_md_personality);
8563 EXPORT_SYMBOL(md_error);
8564 EXPORT_SYMBOL(md_done_sync);
8565 EXPORT_SYMBOL(md_write_start);
8566 EXPORT_SYMBOL(md_write_end);
8567 EXPORT_SYMBOL(md_register_thread);
8568 EXPORT_SYMBOL(md_unregister_thread);
8569 EXPORT_SYMBOL(md_wakeup_thread);
8570 EXPORT_SYMBOL(md_check_recovery);
8571 MODULE_LICENSE("GPL");
8572 MODULE_DESCRIPTION("MD RAID framework");
8573 MODULE_ALIAS("md");
8574 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
8575