xref: /openbmc/linux/drivers/md/md.c (revision 1e2a410ff71504a64d1af2e354287ac51aeac1b0)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/blkdev.h>
37 #include <linux/sysctl.h>
38 #include <linux/seq_file.h>
39 #include <linux/fs.h>
40 #include <linux/poll.h>
41 #include <linux/ctype.h>
42 #include <linux/string.h>
43 #include <linux/hdreg.h>
44 #include <linux/proc_fs.h>
45 #include <linux/random.h>
46 #include <linux/module.h>
47 #include <linux/reboot.h>
48 #include <linux/file.h>
49 #include <linux/compat.h>
50 #include <linux/delay.h>
51 #include <linux/raid/md_p.h>
52 #include <linux/raid/md_u.h>
53 #include <linux/slab.h>
54 #include "md.h"
55 #include "bitmap.h"
56 
57 #ifndef MODULE
58 static void autostart_arrays(int part);
59 #endif
60 
61 /* pers_list is a list of registered personalities protected
62  * by pers_lock.
63  * pers_lock does extra service to protect accesses to
64  * mddev->thread when the mutex cannot be held.
65  */
66 static LIST_HEAD(pers_list);
67 static DEFINE_SPINLOCK(pers_lock);
68 
69 static void md_print_devices(void);
70 
71 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
72 static struct workqueue_struct *md_wq;
73 static struct workqueue_struct *md_misc_wq;
74 
75 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
76 
77 /*
78  * Default number of read corrections we'll attempt on an rdev
79  * before ejecting it from the array. We divide the read error
80  * count by 2 for every hour elapsed between read errors.
81  */
82 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
83 /*
84  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
85  * is 1000 KB/sec, so the extra system load does not show up that much.
86  * Increase it if you want to have more _guaranteed_ speed. Note that
87  * the RAID driver will use the maximum available bandwidth if the IO
88  * subsystem is idle. There is also an 'absolute maximum' reconstruction
89  * speed limit - in case reconstruction slows down your system despite
90  * idle IO detection.
91  *
92  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
93  * or /sys/block/mdX/md/sync_speed_{min,max}
94  */
95 
96 static int sysctl_speed_limit_min = 1000;
97 static int sysctl_speed_limit_max = 200000;
98 static inline int speed_min(struct mddev *mddev)
99 {
100 	return mddev->sync_speed_min ?
101 		mddev->sync_speed_min : sysctl_speed_limit_min;
102 }
103 
104 static inline int speed_max(struct mddev *mddev)
105 {
106 	return mddev->sync_speed_max ?
107 		mddev->sync_speed_max : sysctl_speed_limit_max;
108 }
109 
110 static struct ctl_table_header *raid_table_header;
111 
112 static ctl_table raid_table[] = {
113 	{
114 		.procname	= "speed_limit_min",
115 		.data		= &sysctl_speed_limit_min,
116 		.maxlen		= sizeof(int),
117 		.mode		= S_IRUGO|S_IWUSR,
118 		.proc_handler	= proc_dointvec,
119 	},
120 	{
121 		.procname	= "speed_limit_max",
122 		.data		= &sysctl_speed_limit_max,
123 		.maxlen		= sizeof(int),
124 		.mode		= S_IRUGO|S_IWUSR,
125 		.proc_handler	= proc_dointvec,
126 	},
127 	{ }
128 };
129 
130 static ctl_table raid_dir_table[] = {
131 	{
132 		.procname	= "raid",
133 		.maxlen		= 0,
134 		.mode		= S_IRUGO|S_IXUGO,
135 		.child		= raid_table,
136 	},
137 	{ }
138 };
139 
140 static ctl_table raid_root_table[] = {
141 	{
142 		.procname	= "dev",
143 		.maxlen		= 0,
144 		.mode		= 0555,
145 		.child		= raid_dir_table,
146 	},
147 	{  }
148 };
149 
150 static const struct block_device_operations md_fops;
151 
152 static int start_readonly;
153 
154 /* bio_clone_mddev
155  * like bio_clone, but with a local bio set
156  */
157 
158 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
159 			    struct mddev *mddev)
160 {
161 	struct bio *b;
162 
163 	if (!mddev || !mddev->bio_set)
164 		return bio_alloc(gfp_mask, nr_iovecs);
165 
166 	b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
167 	if (!b)
168 		return NULL;
169 	return b;
170 }
171 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
172 
173 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
174 			    struct mddev *mddev)
175 {
176 	struct bio *b;
177 
178 	if (!mddev || !mddev->bio_set)
179 		return bio_clone(bio, gfp_mask);
180 
181 	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, mddev->bio_set);
182 	if (!b)
183 		return NULL;
184 
185 	__bio_clone(b, bio);
186 	if (bio_integrity(bio)) {
187 		int ret;
188 
189 		ret = bio_integrity_clone(b, bio, gfp_mask);
190 
191 		if (ret < 0) {
192 			bio_put(b);
193 			return NULL;
194 		}
195 	}
196 
197 	return b;
198 }
199 EXPORT_SYMBOL_GPL(bio_clone_mddev);
200 
201 void md_trim_bio(struct bio *bio, int offset, int size)
202 {
203 	/* 'bio' is a cloned bio which we need to trim to match
204 	 * the given offset and size.
205 	 * This requires adjusting bi_sector, bi_size, and bi_io_vec
206 	 */
207 	int i;
208 	struct bio_vec *bvec;
209 	int sofar = 0;
210 
211 	size <<= 9;
212 	if (offset == 0 && size == bio->bi_size)
213 		return;
214 
215 	bio->bi_sector += offset;
216 	bio->bi_size = size;
217 	offset <<= 9;
218 	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
219 
220 	while (bio->bi_idx < bio->bi_vcnt &&
221 	       bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
222 		/* remove this whole bio_vec */
223 		offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
224 		bio->bi_idx++;
225 	}
226 	if (bio->bi_idx < bio->bi_vcnt) {
227 		bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
228 		bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
229 	}
230 	/* avoid any complications with bi_idx being non-zero*/
231 	if (bio->bi_idx) {
232 		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
233 			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
234 		bio->bi_vcnt -= bio->bi_idx;
235 		bio->bi_idx = 0;
236 	}
237 	/* Make sure vcnt and last bv are not too big */
238 	bio_for_each_segment(bvec, bio, i) {
239 		if (sofar + bvec->bv_len > size)
240 			bvec->bv_len = size - sofar;
241 		if (bvec->bv_len == 0) {
242 			bio->bi_vcnt = i;
243 			break;
244 		}
245 		sofar += bvec->bv_len;
246 	}
247 }
248 EXPORT_SYMBOL_GPL(md_trim_bio);
249 
250 /*
251  * We have a system wide 'event count' that is incremented
252  * on any 'interesting' event, and readers of /proc/mdstat
253  * can use 'poll' or 'select' to find out when the event
254  * count increases.
255  *
256  * Events are:
257  *  start array, stop array, error, add device, remove device,
258  *  start build, activate spare
259  */
260 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
261 static atomic_t md_event_count;
262 void md_new_event(struct mddev *mddev)
263 {
264 	atomic_inc(&md_event_count);
265 	wake_up(&md_event_waiters);
266 }
267 EXPORT_SYMBOL_GPL(md_new_event);
268 
269 /* Alternate version that can be called from interrupts
270  * when calling sysfs_notify isn't needed.
271  */
272 static void md_new_event_inintr(struct mddev *mddev)
273 {
274 	atomic_inc(&md_event_count);
275 	wake_up(&md_event_waiters);
276 }
277 
278 /*
279  * Enables to iterate over all existing md arrays
280  * all_mddevs_lock protects this list.
281  */
282 static LIST_HEAD(all_mddevs);
283 static DEFINE_SPINLOCK(all_mddevs_lock);
284 
285 
286 /*
287  * iterates through all used mddevs in the system.
288  * We take care to grab the all_mddevs_lock whenever navigating
289  * the list, and to always hold a refcount when unlocked.
290  * Any code which breaks out of this loop while own
291  * a reference to the current mddev and must mddev_put it.
292  */
293 #define for_each_mddev(_mddev,_tmp)					\
294 									\
295 	for (({ spin_lock(&all_mddevs_lock); 				\
296 		_tmp = all_mddevs.next;					\
297 		_mddev = NULL;});					\
298 	     ({ if (_tmp != &all_mddevs)				\
299 			mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
300 		spin_unlock(&all_mddevs_lock);				\
301 		if (_mddev) mddev_put(_mddev);				\
302 		_mddev = list_entry(_tmp, struct mddev, all_mddevs);	\
303 		_tmp != &all_mddevs;});					\
304 	     ({ spin_lock(&all_mddevs_lock);				\
305 		_tmp = _tmp->next;})					\
306 		)
307 
308 
309 /* Rather than calling directly into the personality make_request function,
310  * IO requests come here first so that we can check if the device is
311  * being suspended pending a reconfiguration.
312  * We hold a refcount over the call to ->make_request.  By the time that
313  * call has finished, the bio has been linked into some internal structure
314  * and so is visible to ->quiesce(), so we don't need the refcount any more.
315  */
316 static void md_make_request(struct request_queue *q, struct bio *bio)
317 {
318 	const int rw = bio_data_dir(bio);
319 	struct mddev *mddev = q->queuedata;
320 	int cpu;
321 	unsigned int sectors;
322 
323 	if (mddev == NULL || mddev->pers == NULL
324 	    || !mddev->ready) {
325 		bio_io_error(bio);
326 		return;
327 	}
328 	smp_rmb(); /* Ensure implications of  'active' are visible */
329 	rcu_read_lock();
330 	if (mddev->suspended) {
331 		DEFINE_WAIT(__wait);
332 		for (;;) {
333 			prepare_to_wait(&mddev->sb_wait, &__wait,
334 					TASK_UNINTERRUPTIBLE);
335 			if (!mddev->suspended)
336 				break;
337 			rcu_read_unlock();
338 			schedule();
339 			rcu_read_lock();
340 		}
341 		finish_wait(&mddev->sb_wait, &__wait);
342 	}
343 	atomic_inc(&mddev->active_io);
344 	rcu_read_unlock();
345 
346 	/*
347 	 * save the sectors now since our bio can
348 	 * go away inside make_request
349 	 */
350 	sectors = bio_sectors(bio);
351 	mddev->pers->make_request(mddev, bio);
352 
353 	cpu = part_stat_lock();
354 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
355 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
356 	part_stat_unlock();
357 
358 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
359 		wake_up(&mddev->sb_wait);
360 }
361 
362 /* mddev_suspend makes sure no new requests are submitted
363  * to the device, and that any requests that have been submitted
364  * are completely handled.
365  * Once ->stop is called and completes, the module will be completely
366  * unused.
367  */
368 void mddev_suspend(struct mddev *mddev)
369 {
370 	BUG_ON(mddev->suspended);
371 	mddev->suspended = 1;
372 	synchronize_rcu();
373 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
374 	mddev->pers->quiesce(mddev, 1);
375 
376 	del_timer_sync(&mddev->safemode_timer);
377 }
378 EXPORT_SYMBOL_GPL(mddev_suspend);
379 
380 void mddev_resume(struct mddev *mddev)
381 {
382 	mddev->suspended = 0;
383 	wake_up(&mddev->sb_wait);
384 	mddev->pers->quiesce(mddev, 0);
385 
386 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
387 	md_wakeup_thread(mddev->thread);
388 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
389 }
390 EXPORT_SYMBOL_GPL(mddev_resume);
391 
392 int mddev_congested(struct mddev *mddev, int bits)
393 {
394 	return mddev->suspended;
395 }
396 EXPORT_SYMBOL(mddev_congested);
397 
398 /*
399  * Generic flush handling for md
400  */
401 
402 static void md_end_flush(struct bio *bio, int err)
403 {
404 	struct md_rdev *rdev = bio->bi_private;
405 	struct mddev *mddev = rdev->mddev;
406 
407 	rdev_dec_pending(rdev, mddev);
408 
409 	if (atomic_dec_and_test(&mddev->flush_pending)) {
410 		/* The pre-request flush has finished */
411 		queue_work(md_wq, &mddev->flush_work);
412 	}
413 	bio_put(bio);
414 }
415 
416 static void md_submit_flush_data(struct work_struct *ws);
417 
418 static void submit_flushes(struct work_struct *ws)
419 {
420 	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
421 	struct md_rdev *rdev;
422 
423 	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
424 	atomic_set(&mddev->flush_pending, 1);
425 	rcu_read_lock();
426 	rdev_for_each_rcu(rdev, mddev)
427 		if (rdev->raid_disk >= 0 &&
428 		    !test_bit(Faulty, &rdev->flags)) {
429 			/* Take two references, one is dropped
430 			 * when request finishes, one after
431 			 * we reclaim rcu_read_lock
432 			 */
433 			struct bio *bi;
434 			atomic_inc(&rdev->nr_pending);
435 			atomic_inc(&rdev->nr_pending);
436 			rcu_read_unlock();
437 			bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
438 			bi->bi_end_io = md_end_flush;
439 			bi->bi_private = rdev;
440 			bi->bi_bdev = rdev->bdev;
441 			atomic_inc(&mddev->flush_pending);
442 			submit_bio(WRITE_FLUSH, bi);
443 			rcu_read_lock();
444 			rdev_dec_pending(rdev, mddev);
445 		}
446 	rcu_read_unlock();
447 	if (atomic_dec_and_test(&mddev->flush_pending))
448 		queue_work(md_wq, &mddev->flush_work);
449 }
450 
451 static void md_submit_flush_data(struct work_struct *ws)
452 {
453 	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
454 	struct bio *bio = mddev->flush_bio;
455 
456 	if (bio->bi_size == 0)
457 		/* an empty barrier - all done */
458 		bio_endio(bio, 0);
459 	else {
460 		bio->bi_rw &= ~REQ_FLUSH;
461 		mddev->pers->make_request(mddev, bio);
462 	}
463 
464 	mddev->flush_bio = NULL;
465 	wake_up(&mddev->sb_wait);
466 }
467 
468 void md_flush_request(struct mddev *mddev, struct bio *bio)
469 {
470 	spin_lock_irq(&mddev->write_lock);
471 	wait_event_lock_irq(mddev->sb_wait,
472 			    !mddev->flush_bio,
473 			    mddev->write_lock, /*nothing*/);
474 	mddev->flush_bio = bio;
475 	spin_unlock_irq(&mddev->write_lock);
476 
477 	INIT_WORK(&mddev->flush_work, submit_flushes);
478 	queue_work(md_wq, &mddev->flush_work);
479 }
480 EXPORT_SYMBOL(md_flush_request);
481 
482 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
483 {
484 	struct mddev *mddev = cb->data;
485 	md_wakeup_thread(mddev->thread);
486 	kfree(cb);
487 }
488 EXPORT_SYMBOL(md_unplug);
489 
490 static inline struct mddev *mddev_get(struct mddev *mddev)
491 {
492 	atomic_inc(&mddev->active);
493 	return mddev;
494 }
495 
496 static void mddev_delayed_delete(struct work_struct *ws);
497 
498 static void mddev_put(struct mddev *mddev)
499 {
500 	struct bio_set *bs = NULL;
501 
502 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
503 		return;
504 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
505 	    mddev->ctime == 0 && !mddev->hold_active) {
506 		/* Array is not configured at all, and not held active,
507 		 * so destroy it */
508 		list_del_init(&mddev->all_mddevs);
509 		bs = mddev->bio_set;
510 		mddev->bio_set = NULL;
511 		if (mddev->gendisk) {
512 			/* We did a probe so need to clean up.  Call
513 			 * queue_work inside the spinlock so that
514 			 * flush_workqueue() after mddev_find will
515 			 * succeed in waiting for the work to be done.
516 			 */
517 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
518 			queue_work(md_misc_wq, &mddev->del_work);
519 		} else
520 			kfree(mddev);
521 	}
522 	spin_unlock(&all_mddevs_lock);
523 	if (bs)
524 		bioset_free(bs);
525 }
526 
527 void mddev_init(struct mddev *mddev)
528 {
529 	mutex_init(&mddev->open_mutex);
530 	mutex_init(&mddev->reconfig_mutex);
531 	mutex_init(&mddev->bitmap_info.mutex);
532 	INIT_LIST_HEAD(&mddev->disks);
533 	INIT_LIST_HEAD(&mddev->all_mddevs);
534 	init_timer(&mddev->safemode_timer);
535 	atomic_set(&mddev->active, 1);
536 	atomic_set(&mddev->openers, 0);
537 	atomic_set(&mddev->active_io, 0);
538 	spin_lock_init(&mddev->write_lock);
539 	atomic_set(&mddev->flush_pending, 0);
540 	init_waitqueue_head(&mddev->sb_wait);
541 	init_waitqueue_head(&mddev->recovery_wait);
542 	mddev->reshape_position = MaxSector;
543 	mddev->reshape_backwards = 0;
544 	mddev->resync_min = 0;
545 	mddev->resync_max = MaxSector;
546 	mddev->level = LEVEL_NONE;
547 }
548 EXPORT_SYMBOL_GPL(mddev_init);
549 
550 static struct mddev * mddev_find(dev_t unit)
551 {
552 	struct mddev *mddev, *new = NULL;
553 
554 	if (unit && MAJOR(unit) != MD_MAJOR)
555 		unit &= ~((1<<MdpMinorShift)-1);
556 
557  retry:
558 	spin_lock(&all_mddevs_lock);
559 
560 	if (unit) {
561 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
562 			if (mddev->unit == unit) {
563 				mddev_get(mddev);
564 				spin_unlock(&all_mddevs_lock);
565 				kfree(new);
566 				return mddev;
567 			}
568 
569 		if (new) {
570 			list_add(&new->all_mddevs, &all_mddevs);
571 			spin_unlock(&all_mddevs_lock);
572 			new->hold_active = UNTIL_IOCTL;
573 			return new;
574 		}
575 	} else if (new) {
576 		/* find an unused unit number */
577 		static int next_minor = 512;
578 		int start = next_minor;
579 		int is_free = 0;
580 		int dev = 0;
581 		while (!is_free) {
582 			dev = MKDEV(MD_MAJOR, next_minor);
583 			next_minor++;
584 			if (next_minor > MINORMASK)
585 				next_minor = 0;
586 			if (next_minor == start) {
587 				/* Oh dear, all in use. */
588 				spin_unlock(&all_mddevs_lock);
589 				kfree(new);
590 				return NULL;
591 			}
592 
593 			is_free = 1;
594 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
595 				if (mddev->unit == dev) {
596 					is_free = 0;
597 					break;
598 				}
599 		}
600 		new->unit = dev;
601 		new->md_minor = MINOR(dev);
602 		new->hold_active = UNTIL_STOP;
603 		list_add(&new->all_mddevs, &all_mddevs);
604 		spin_unlock(&all_mddevs_lock);
605 		return new;
606 	}
607 	spin_unlock(&all_mddevs_lock);
608 
609 	new = kzalloc(sizeof(*new), GFP_KERNEL);
610 	if (!new)
611 		return NULL;
612 
613 	new->unit = unit;
614 	if (MAJOR(unit) == MD_MAJOR)
615 		new->md_minor = MINOR(unit);
616 	else
617 		new->md_minor = MINOR(unit) >> MdpMinorShift;
618 
619 	mddev_init(new);
620 
621 	goto retry;
622 }
623 
624 static inline int mddev_lock(struct mddev * mddev)
625 {
626 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
627 }
628 
629 static inline int mddev_is_locked(struct mddev *mddev)
630 {
631 	return mutex_is_locked(&mddev->reconfig_mutex);
632 }
633 
634 static inline int mddev_trylock(struct mddev * mddev)
635 {
636 	return mutex_trylock(&mddev->reconfig_mutex);
637 }
638 
639 static struct attribute_group md_redundancy_group;
640 
641 static void mddev_unlock(struct mddev * mddev)
642 {
643 	if (mddev->to_remove) {
644 		/* These cannot be removed under reconfig_mutex as
645 		 * an access to the files will try to take reconfig_mutex
646 		 * while holding the file unremovable, which leads to
647 		 * a deadlock.
648 		 * So hold set sysfs_active while the remove in happeing,
649 		 * and anything else which might set ->to_remove or my
650 		 * otherwise change the sysfs namespace will fail with
651 		 * -EBUSY if sysfs_active is still set.
652 		 * We set sysfs_active under reconfig_mutex and elsewhere
653 		 * test it under the same mutex to ensure its correct value
654 		 * is seen.
655 		 */
656 		struct attribute_group *to_remove = mddev->to_remove;
657 		mddev->to_remove = NULL;
658 		mddev->sysfs_active = 1;
659 		mutex_unlock(&mddev->reconfig_mutex);
660 
661 		if (mddev->kobj.sd) {
662 			if (to_remove != &md_redundancy_group)
663 				sysfs_remove_group(&mddev->kobj, to_remove);
664 			if (mddev->pers == NULL ||
665 			    mddev->pers->sync_request == NULL) {
666 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
667 				if (mddev->sysfs_action)
668 					sysfs_put(mddev->sysfs_action);
669 				mddev->sysfs_action = NULL;
670 			}
671 		}
672 		mddev->sysfs_active = 0;
673 	} else
674 		mutex_unlock(&mddev->reconfig_mutex);
675 
676 	/* As we've dropped the mutex we need a spinlock to
677 	 * make sure the thread doesn't disappear
678 	 */
679 	spin_lock(&pers_lock);
680 	md_wakeup_thread(mddev->thread);
681 	spin_unlock(&pers_lock);
682 }
683 
684 static struct md_rdev * find_rdev_nr(struct mddev *mddev, int nr)
685 {
686 	struct md_rdev *rdev;
687 
688 	rdev_for_each(rdev, mddev)
689 		if (rdev->desc_nr == nr)
690 			return rdev;
691 
692 	return NULL;
693 }
694 
695 static struct md_rdev * find_rdev(struct mddev * mddev, dev_t dev)
696 {
697 	struct md_rdev *rdev;
698 
699 	rdev_for_each(rdev, mddev)
700 		if (rdev->bdev->bd_dev == dev)
701 			return rdev;
702 
703 	return NULL;
704 }
705 
706 static struct md_personality *find_pers(int level, char *clevel)
707 {
708 	struct md_personality *pers;
709 	list_for_each_entry(pers, &pers_list, list) {
710 		if (level != LEVEL_NONE && pers->level == level)
711 			return pers;
712 		if (strcmp(pers->name, clevel)==0)
713 			return pers;
714 	}
715 	return NULL;
716 }
717 
718 /* return the offset of the super block in 512byte sectors */
719 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
720 {
721 	sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
722 	return MD_NEW_SIZE_SECTORS(num_sectors);
723 }
724 
725 static int alloc_disk_sb(struct md_rdev * rdev)
726 {
727 	if (rdev->sb_page)
728 		MD_BUG();
729 
730 	rdev->sb_page = alloc_page(GFP_KERNEL);
731 	if (!rdev->sb_page) {
732 		printk(KERN_ALERT "md: out of memory.\n");
733 		return -ENOMEM;
734 	}
735 
736 	return 0;
737 }
738 
739 void md_rdev_clear(struct md_rdev *rdev)
740 {
741 	if (rdev->sb_page) {
742 		put_page(rdev->sb_page);
743 		rdev->sb_loaded = 0;
744 		rdev->sb_page = NULL;
745 		rdev->sb_start = 0;
746 		rdev->sectors = 0;
747 	}
748 	if (rdev->bb_page) {
749 		put_page(rdev->bb_page);
750 		rdev->bb_page = NULL;
751 	}
752 	kfree(rdev->badblocks.page);
753 	rdev->badblocks.page = NULL;
754 }
755 EXPORT_SYMBOL_GPL(md_rdev_clear);
756 
757 static void super_written(struct bio *bio, int error)
758 {
759 	struct md_rdev *rdev = bio->bi_private;
760 	struct mddev *mddev = rdev->mddev;
761 
762 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
763 		printk("md: super_written gets error=%d, uptodate=%d\n",
764 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
765 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
766 		md_error(mddev, rdev);
767 	}
768 
769 	if (atomic_dec_and_test(&mddev->pending_writes))
770 		wake_up(&mddev->sb_wait);
771 	bio_put(bio);
772 }
773 
774 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
775 		   sector_t sector, int size, struct page *page)
776 {
777 	/* write first size bytes of page to sector of rdev
778 	 * Increment mddev->pending_writes before returning
779 	 * and decrement it on completion, waking up sb_wait
780 	 * if zero is reached.
781 	 * If an error occurred, call md_error
782 	 */
783 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
784 
785 	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
786 	bio->bi_sector = sector;
787 	bio_add_page(bio, page, size, 0);
788 	bio->bi_private = rdev;
789 	bio->bi_end_io = super_written;
790 
791 	atomic_inc(&mddev->pending_writes);
792 	submit_bio(WRITE_FLUSH_FUA, bio);
793 }
794 
795 void md_super_wait(struct mddev *mddev)
796 {
797 	/* wait for all superblock writes that were scheduled to complete */
798 	DEFINE_WAIT(wq);
799 	for(;;) {
800 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
801 		if (atomic_read(&mddev->pending_writes)==0)
802 			break;
803 		schedule();
804 	}
805 	finish_wait(&mddev->sb_wait, &wq);
806 }
807 
808 static void bi_complete(struct bio *bio, int error)
809 {
810 	complete((struct completion*)bio->bi_private);
811 }
812 
813 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
814 		 struct page *page, int rw, bool metadata_op)
815 {
816 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
817 	struct completion event;
818 	int ret;
819 
820 	rw |= REQ_SYNC;
821 
822 	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
823 		rdev->meta_bdev : rdev->bdev;
824 	if (metadata_op)
825 		bio->bi_sector = sector + rdev->sb_start;
826 	else if (rdev->mddev->reshape_position != MaxSector &&
827 		 (rdev->mddev->reshape_backwards ==
828 		  (sector >= rdev->mddev->reshape_position)))
829 		bio->bi_sector = sector + rdev->new_data_offset;
830 	else
831 		bio->bi_sector = sector + rdev->data_offset;
832 	bio_add_page(bio, page, size, 0);
833 	init_completion(&event);
834 	bio->bi_private = &event;
835 	bio->bi_end_io = bi_complete;
836 	submit_bio(rw, bio);
837 	wait_for_completion(&event);
838 
839 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
840 	bio_put(bio);
841 	return ret;
842 }
843 EXPORT_SYMBOL_GPL(sync_page_io);
844 
845 static int read_disk_sb(struct md_rdev * rdev, int size)
846 {
847 	char b[BDEVNAME_SIZE];
848 	if (!rdev->sb_page) {
849 		MD_BUG();
850 		return -EINVAL;
851 	}
852 	if (rdev->sb_loaded)
853 		return 0;
854 
855 
856 	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
857 		goto fail;
858 	rdev->sb_loaded = 1;
859 	return 0;
860 
861 fail:
862 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
863 		bdevname(rdev->bdev,b));
864 	return -EINVAL;
865 }
866 
867 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
868 {
869 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
870 		sb1->set_uuid1 == sb2->set_uuid1 &&
871 		sb1->set_uuid2 == sb2->set_uuid2 &&
872 		sb1->set_uuid3 == sb2->set_uuid3;
873 }
874 
875 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
876 {
877 	int ret;
878 	mdp_super_t *tmp1, *tmp2;
879 
880 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
881 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
882 
883 	if (!tmp1 || !tmp2) {
884 		ret = 0;
885 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
886 		goto abort;
887 	}
888 
889 	*tmp1 = *sb1;
890 	*tmp2 = *sb2;
891 
892 	/*
893 	 * nr_disks is not constant
894 	 */
895 	tmp1->nr_disks = 0;
896 	tmp2->nr_disks = 0;
897 
898 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
899 abort:
900 	kfree(tmp1);
901 	kfree(tmp2);
902 	return ret;
903 }
904 
905 
906 static u32 md_csum_fold(u32 csum)
907 {
908 	csum = (csum & 0xffff) + (csum >> 16);
909 	return (csum & 0xffff) + (csum >> 16);
910 }
911 
912 static unsigned int calc_sb_csum(mdp_super_t * sb)
913 {
914 	u64 newcsum = 0;
915 	u32 *sb32 = (u32*)sb;
916 	int i;
917 	unsigned int disk_csum, csum;
918 
919 	disk_csum = sb->sb_csum;
920 	sb->sb_csum = 0;
921 
922 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
923 		newcsum += sb32[i];
924 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
925 
926 
927 #ifdef CONFIG_ALPHA
928 	/* This used to use csum_partial, which was wrong for several
929 	 * reasons including that different results are returned on
930 	 * different architectures.  It isn't critical that we get exactly
931 	 * the same return value as before (we always csum_fold before
932 	 * testing, and that removes any differences).  However as we
933 	 * know that csum_partial always returned a 16bit value on
934 	 * alphas, do a fold to maximise conformity to previous behaviour.
935 	 */
936 	sb->sb_csum = md_csum_fold(disk_csum);
937 #else
938 	sb->sb_csum = disk_csum;
939 #endif
940 	return csum;
941 }
942 
943 
944 /*
945  * Handle superblock details.
946  * We want to be able to handle multiple superblock formats
947  * so we have a common interface to them all, and an array of
948  * different handlers.
949  * We rely on user-space to write the initial superblock, and support
950  * reading and updating of superblocks.
951  * Interface methods are:
952  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
953  *      loads and validates a superblock on dev.
954  *      if refdev != NULL, compare superblocks on both devices
955  *    Return:
956  *      0 - dev has a superblock that is compatible with refdev
957  *      1 - dev has a superblock that is compatible and newer than refdev
958  *          so dev should be used as the refdev in future
959  *     -EINVAL superblock incompatible or invalid
960  *     -othererror e.g. -EIO
961  *
962  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
963  *      Verify that dev is acceptable into mddev.
964  *       The first time, mddev->raid_disks will be 0, and data from
965  *       dev should be merged in.  Subsequent calls check that dev
966  *       is new enough.  Return 0 or -EINVAL
967  *
968  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
969  *     Update the superblock for rdev with data in mddev
970  *     This does not write to disc.
971  *
972  */
973 
974 struct super_type  {
975 	char		    *name;
976 	struct module	    *owner;
977 	int		    (*load_super)(struct md_rdev *rdev,
978 					  struct md_rdev *refdev,
979 					  int minor_version);
980 	int		    (*validate_super)(struct mddev *mddev,
981 					      struct md_rdev *rdev);
982 	void		    (*sync_super)(struct mddev *mddev,
983 					  struct md_rdev *rdev);
984 	unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
985 						sector_t num_sectors);
986 	int		    (*allow_new_offset)(struct md_rdev *rdev,
987 						unsigned long long new_offset);
988 };
989 
990 /*
991  * Check that the given mddev has no bitmap.
992  *
993  * This function is called from the run method of all personalities that do not
994  * support bitmaps. It prints an error message and returns non-zero if mddev
995  * has a bitmap. Otherwise, it returns 0.
996  *
997  */
998 int md_check_no_bitmap(struct mddev *mddev)
999 {
1000 	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
1001 		return 0;
1002 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
1003 		mdname(mddev), mddev->pers->name);
1004 	return 1;
1005 }
1006 EXPORT_SYMBOL(md_check_no_bitmap);
1007 
1008 /*
1009  * load_super for 0.90.0
1010  */
1011 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1012 {
1013 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1014 	mdp_super_t *sb;
1015 	int ret;
1016 
1017 	/*
1018 	 * Calculate the position of the superblock (512byte sectors),
1019 	 * it's at the end of the disk.
1020 	 *
1021 	 * It also happens to be a multiple of 4Kb.
1022 	 */
1023 	rdev->sb_start = calc_dev_sboffset(rdev);
1024 
1025 	ret = read_disk_sb(rdev, MD_SB_BYTES);
1026 	if (ret) return ret;
1027 
1028 	ret = -EINVAL;
1029 
1030 	bdevname(rdev->bdev, b);
1031 	sb = page_address(rdev->sb_page);
1032 
1033 	if (sb->md_magic != MD_SB_MAGIC) {
1034 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
1035 		       b);
1036 		goto abort;
1037 	}
1038 
1039 	if (sb->major_version != 0 ||
1040 	    sb->minor_version < 90 ||
1041 	    sb->minor_version > 91) {
1042 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1043 			sb->major_version, sb->minor_version,
1044 			b);
1045 		goto abort;
1046 	}
1047 
1048 	if (sb->raid_disks <= 0)
1049 		goto abort;
1050 
1051 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1052 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1053 			b);
1054 		goto abort;
1055 	}
1056 
1057 	rdev->preferred_minor = sb->md_minor;
1058 	rdev->data_offset = 0;
1059 	rdev->new_data_offset = 0;
1060 	rdev->sb_size = MD_SB_BYTES;
1061 	rdev->badblocks.shift = -1;
1062 
1063 	if (sb->level == LEVEL_MULTIPATH)
1064 		rdev->desc_nr = -1;
1065 	else
1066 		rdev->desc_nr = sb->this_disk.number;
1067 
1068 	if (!refdev) {
1069 		ret = 1;
1070 	} else {
1071 		__u64 ev1, ev2;
1072 		mdp_super_t *refsb = page_address(refdev->sb_page);
1073 		if (!uuid_equal(refsb, sb)) {
1074 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
1075 				b, bdevname(refdev->bdev,b2));
1076 			goto abort;
1077 		}
1078 		if (!sb_equal(refsb, sb)) {
1079 			printk(KERN_WARNING "md: %s has same UUID"
1080 			       " but different superblock to %s\n",
1081 			       b, bdevname(refdev->bdev, b2));
1082 			goto abort;
1083 		}
1084 		ev1 = md_event(sb);
1085 		ev2 = md_event(refsb);
1086 		if (ev1 > ev2)
1087 			ret = 1;
1088 		else
1089 			ret = 0;
1090 	}
1091 	rdev->sectors = rdev->sb_start;
1092 	/* Limit to 4TB as metadata cannot record more than that.
1093 	 * (not needed for Linear and RAID0 as metadata doesn't
1094 	 * record this size)
1095 	 */
1096 	if (rdev->sectors >= (2ULL << 32) && sb->level >= 1)
1097 		rdev->sectors = (2ULL << 32) - 2;
1098 
1099 	if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1100 		/* "this cannot possibly happen" ... */
1101 		ret = -EINVAL;
1102 
1103  abort:
1104 	return ret;
1105 }
1106 
1107 /*
1108  * validate_super for 0.90.0
1109  */
1110 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1111 {
1112 	mdp_disk_t *desc;
1113 	mdp_super_t *sb = page_address(rdev->sb_page);
1114 	__u64 ev1 = md_event(sb);
1115 
1116 	rdev->raid_disk = -1;
1117 	clear_bit(Faulty, &rdev->flags);
1118 	clear_bit(In_sync, &rdev->flags);
1119 	clear_bit(WriteMostly, &rdev->flags);
1120 
1121 	if (mddev->raid_disks == 0) {
1122 		mddev->major_version = 0;
1123 		mddev->minor_version = sb->minor_version;
1124 		mddev->patch_version = sb->patch_version;
1125 		mddev->external = 0;
1126 		mddev->chunk_sectors = sb->chunk_size >> 9;
1127 		mddev->ctime = sb->ctime;
1128 		mddev->utime = sb->utime;
1129 		mddev->level = sb->level;
1130 		mddev->clevel[0] = 0;
1131 		mddev->layout = sb->layout;
1132 		mddev->raid_disks = sb->raid_disks;
1133 		mddev->dev_sectors = ((sector_t)sb->size) * 2;
1134 		mddev->events = ev1;
1135 		mddev->bitmap_info.offset = 0;
1136 		mddev->bitmap_info.space = 0;
1137 		/* bitmap can use 60 K after the 4K superblocks */
1138 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1139 		mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1140 		mddev->reshape_backwards = 0;
1141 
1142 		if (mddev->minor_version >= 91) {
1143 			mddev->reshape_position = sb->reshape_position;
1144 			mddev->delta_disks = sb->delta_disks;
1145 			mddev->new_level = sb->new_level;
1146 			mddev->new_layout = sb->new_layout;
1147 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1148 			if (mddev->delta_disks < 0)
1149 				mddev->reshape_backwards = 1;
1150 		} else {
1151 			mddev->reshape_position = MaxSector;
1152 			mddev->delta_disks = 0;
1153 			mddev->new_level = mddev->level;
1154 			mddev->new_layout = mddev->layout;
1155 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1156 		}
1157 
1158 		if (sb->state & (1<<MD_SB_CLEAN))
1159 			mddev->recovery_cp = MaxSector;
1160 		else {
1161 			if (sb->events_hi == sb->cp_events_hi &&
1162 				sb->events_lo == sb->cp_events_lo) {
1163 				mddev->recovery_cp = sb->recovery_cp;
1164 			} else
1165 				mddev->recovery_cp = 0;
1166 		}
1167 
1168 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1169 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1170 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1171 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1172 
1173 		mddev->max_disks = MD_SB_DISKS;
1174 
1175 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1176 		    mddev->bitmap_info.file == NULL) {
1177 			mddev->bitmap_info.offset =
1178 				mddev->bitmap_info.default_offset;
1179 			mddev->bitmap_info.space =
1180 				mddev->bitmap_info.space;
1181 		}
1182 
1183 	} else if (mddev->pers == NULL) {
1184 		/* Insist on good event counter while assembling, except
1185 		 * for spares (which don't need an event count) */
1186 		++ev1;
1187 		if (sb->disks[rdev->desc_nr].state & (
1188 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1189 			if (ev1 < mddev->events)
1190 				return -EINVAL;
1191 	} else if (mddev->bitmap) {
1192 		/* if adding to array with a bitmap, then we can accept an
1193 		 * older device ... but not too old.
1194 		 */
1195 		if (ev1 < mddev->bitmap->events_cleared)
1196 			return 0;
1197 	} else {
1198 		if (ev1 < mddev->events)
1199 			/* just a hot-add of a new device, leave raid_disk at -1 */
1200 			return 0;
1201 	}
1202 
1203 	if (mddev->level != LEVEL_MULTIPATH) {
1204 		desc = sb->disks + rdev->desc_nr;
1205 
1206 		if (desc->state & (1<<MD_DISK_FAULTY))
1207 			set_bit(Faulty, &rdev->flags);
1208 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1209 			    desc->raid_disk < mddev->raid_disks */) {
1210 			set_bit(In_sync, &rdev->flags);
1211 			rdev->raid_disk = desc->raid_disk;
1212 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1213 			/* active but not in sync implies recovery up to
1214 			 * reshape position.  We don't know exactly where
1215 			 * that is, so set to zero for now */
1216 			if (mddev->minor_version >= 91) {
1217 				rdev->recovery_offset = 0;
1218 				rdev->raid_disk = desc->raid_disk;
1219 			}
1220 		}
1221 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1222 			set_bit(WriteMostly, &rdev->flags);
1223 	} else /* MULTIPATH are always insync */
1224 		set_bit(In_sync, &rdev->flags);
1225 	return 0;
1226 }
1227 
1228 /*
1229  * sync_super for 0.90.0
1230  */
1231 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1232 {
1233 	mdp_super_t *sb;
1234 	struct md_rdev *rdev2;
1235 	int next_spare = mddev->raid_disks;
1236 
1237 
1238 	/* make rdev->sb match mddev data..
1239 	 *
1240 	 * 1/ zero out disks
1241 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1242 	 * 3/ any empty disks < next_spare become removed
1243 	 *
1244 	 * disks[0] gets initialised to REMOVED because
1245 	 * we cannot be sure from other fields if it has
1246 	 * been initialised or not.
1247 	 */
1248 	int i;
1249 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1250 
1251 	rdev->sb_size = MD_SB_BYTES;
1252 
1253 	sb = page_address(rdev->sb_page);
1254 
1255 	memset(sb, 0, sizeof(*sb));
1256 
1257 	sb->md_magic = MD_SB_MAGIC;
1258 	sb->major_version = mddev->major_version;
1259 	sb->patch_version = mddev->patch_version;
1260 	sb->gvalid_words  = 0; /* ignored */
1261 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1262 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1263 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1264 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1265 
1266 	sb->ctime = mddev->ctime;
1267 	sb->level = mddev->level;
1268 	sb->size = mddev->dev_sectors / 2;
1269 	sb->raid_disks = mddev->raid_disks;
1270 	sb->md_minor = mddev->md_minor;
1271 	sb->not_persistent = 0;
1272 	sb->utime = mddev->utime;
1273 	sb->state = 0;
1274 	sb->events_hi = (mddev->events>>32);
1275 	sb->events_lo = (u32)mddev->events;
1276 
1277 	if (mddev->reshape_position == MaxSector)
1278 		sb->minor_version = 90;
1279 	else {
1280 		sb->minor_version = 91;
1281 		sb->reshape_position = mddev->reshape_position;
1282 		sb->new_level = mddev->new_level;
1283 		sb->delta_disks = mddev->delta_disks;
1284 		sb->new_layout = mddev->new_layout;
1285 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1286 	}
1287 	mddev->minor_version = sb->minor_version;
1288 	if (mddev->in_sync)
1289 	{
1290 		sb->recovery_cp = mddev->recovery_cp;
1291 		sb->cp_events_hi = (mddev->events>>32);
1292 		sb->cp_events_lo = (u32)mddev->events;
1293 		if (mddev->recovery_cp == MaxSector)
1294 			sb->state = (1<< MD_SB_CLEAN);
1295 	} else
1296 		sb->recovery_cp = 0;
1297 
1298 	sb->layout = mddev->layout;
1299 	sb->chunk_size = mddev->chunk_sectors << 9;
1300 
1301 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1302 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1303 
1304 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1305 	rdev_for_each(rdev2, mddev) {
1306 		mdp_disk_t *d;
1307 		int desc_nr;
1308 		int is_active = test_bit(In_sync, &rdev2->flags);
1309 
1310 		if (rdev2->raid_disk >= 0 &&
1311 		    sb->minor_version >= 91)
1312 			/* we have nowhere to store the recovery_offset,
1313 			 * but if it is not below the reshape_position,
1314 			 * we can piggy-back on that.
1315 			 */
1316 			is_active = 1;
1317 		if (rdev2->raid_disk < 0 ||
1318 		    test_bit(Faulty, &rdev2->flags))
1319 			is_active = 0;
1320 		if (is_active)
1321 			desc_nr = rdev2->raid_disk;
1322 		else
1323 			desc_nr = next_spare++;
1324 		rdev2->desc_nr = desc_nr;
1325 		d = &sb->disks[rdev2->desc_nr];
1326 		nr_disks++;
1327 		d->number = rdev2->desc_nr;
1328 		d->major = MAJOR(rdev2->bdev->bd_dev);
1329 		d->minor = MINOR(rdev2->bdev->bd_dev);
1330 		if (is_active)
1331 			d->raid_disk = rdev2->raid_disk;
1332 		else
1333 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1334 		if (test_bit(Faulty, &rdev2->flags))
1335 			d->state = (1<<MD_DISK_FAULTY);
1336 		else if (is_active) {
1337 			d->state = (1<<MD_DISK_ACTIVE);
1338 			if (test_bit(In_sync, &rdev2->flags))
1339 				d->state |= (1<<MD_DISK_SYNC);
1340 			active++;
1341 			working++;
1342 		} else {
1343 			d->state = 0;
1344 			spare++;
1345 			working++;
1346 		}
1347 		if (test_bit(WriteMostly, &rdev2->flags))
1348 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1349 	}
1350 	/* now set the "removed" and "faulty" bits on any missing devices */
1351 	for (i=0 ; i < mddev->raid_disks ; i++) {
1352 		mdp_disk_t *d = &sb->disks[i];
1353 		if (d->state == 0 && d->number == 0) {
1354 			d->number = i;
1355 			d->raid_disk = i;
1356 			d->state = (1<<MD_DISK_REMOVED);
1357 			d->state |= (1<<MD_DISK_FAULTY);
1358 			failed++;
1359 		}
1360 	}
1361 	sb->nr_disks = nr_disks;
1362 	sb->active_disks = active;
1363 	sb->working_disks = working;
1364 	sb->failed_disks = failed;
1365 	sb->spare_disks = spare;
1366 
1367 	sb->this_disk = sb->disks[rdev->desc_nr];
1368 	sb->sb_csum = calc_sb_csum(sb);
1369 }
1370 
1371 /*
1372  * rdev_size_change for 0.90.0
1373  */
1374 static unsigned long long
1375 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1376 {
1377 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1378 		return 0; /* component must fit device */
1379 	if (rdev->mddev->bitmap_info.offset)
1380 		return 0; /* can't move bitmap */
1381 	rdev->sb_start = calc_dev_sboffset(rdev);
1382 	if (!num_sectors || num_sectors > rdev->sb_start)
1383 		num_sectors = rdev->sb_start;
1384 	/* Limit to 4TB as metadata cannot record more than that.
1385 	 * 4TB == 2^32 KB, or 2*2^32 sectors.
1386 	 */
1387 	if (num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
1388 		num_sectors = (2ULL << 32) - 2;
1389 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1390 		       rdev->sb_page);
1391 	md_super_wait(rdev->mddev);
1392 	return num_sectors;
1393 }
1394 
1395 static int
1396 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1397 {
1398 	/* non-zero offset changes not possible with v0.90 */
1399 	return new_offset == 0;
1400 }
1401 
1402 /*
1403  * version 1 superblock
1404  */
1405 
1406 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1407 {
1408 	__le32 disk_csum;
1409 	u32 csum;
1410 	unsigned long long newcsum;
1411 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1412 	__le32 *isuper = (__le32*)sb;
1413 	int i;
1414 
1415 	disk_csum = sb->sb_csum;
1416 	sb->sb_csum = 0;
1417 	newcsum = 0;
1418 	for (i=0; size>=4; size -= 4 )
1419 		newcsum += le32_to_cpu(*isuper++);
1420 
1421 	if (size == 2)
1422 		newcsum += le16_to_cpu(*(__le16*) isuper);
1423 
1424 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1425 	sb->sb_csum = disk_csum;
1426 	return cpu_to_le32(csum);
1427 }
1428 
1429 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1430 			    int acknowledged);
1431 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1432 {
1433 	struct mdp_superblock_1 *sb;
1434 	int ret;
1435 	sector_t sb_start;
1436 	sector_t sectors;
1437 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1438 	int bmask;
1439 
1440 	/*
1441 	 * Calculate the position of the superblock in 512byte sectors.
1442 	 * It is always aligned to a 4K boundary and
1443 	 * depeding on minor_version, it can be:
1444 	 * 0: At least 8K, but less than 12K, from end of device
1445 	 * 1: At start of device
1446 	 * 2: 4K from start of device.
1447 	 */
1448 	switch(minor_version) {
1449 	case 0:
1450 		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1451 		sb_start -= 8*2;
1452 		sb_start &= ~(sector_t)(4*2-1);
1453 		break;
1454 	case 1:
1455 		sb_start = 0;
1456 		break;
1457 	case 2:
1458 		sb_start = 8;
1459 		break;
1460 	default:
1461 		return -EINVAL;
1462 	}
1463 	rdev->sb_start = sb_start;
1464 
1465 	/* superblock is rarely larger than 1K, but it can be larger,
1466 	 * and it is safe to read 4k, so we do that
1467 	 */
1468 	ret = read_disk_sb(rdev, 4096);
1469 	if (ret) return ret;
1470 
1471 
1472 	sb = page_address(rdev->sb_page);
1473 
1474 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1475 	    sb->major_version != cpu_to_le32(1) ||
1476 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1477 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1478 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1479 		return -EINVAL;
1480 
1481 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1482 		printk("md: invalid superblock checksum on %s\n",
1483 			bdevname(rdev->bdev,b));
1484 		return -EINVAL;
1485 	}
1486 	if (le64_to_cpu(sb->data_size) < 10) {
1487 		printk("md: data_size too small on %s\n",
1488 		       bdevname(rdev->bdev,b));
1489 		return -EINVAL;
1490 	}
1491 	if (sb->pad0 ||
1492 	    sb->pad3[0] ||
1493 	    memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1494 		/* Some padding is non-zero, might be a new feature */
1495 		return -EINVAL;
1496 
1497 	rdev->preferred_minor = 0xffff;
1498 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1499 	rdev->new_data_offset = rdev->data_offset;
1500 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1501 	    (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1502 		rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1503 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1504 
1505 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1506 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1507 	if (rdev->sb_size & bmask)
1508 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1509 
1510 	if (minor_version
1511 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1512 		return -EINVAL;
1513 	if (minor_version
1514 	    && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1515 		return -EINVAL;
1516 
1517 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1518 		rdev->desc_nr = -1;
1519 	else
1520 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1521 
1522 	if (!rdev->bb_page) {
1523 		rdev->bb_page = alloc_page(GFP_KERNEL);
1524 		if (!rdev->bb_page)
1525 			return -ENOMEM;
1526 	}
1527 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1528 	    rdev->badblocks.count == 0) {
1529 		/* need to load the bad block list.
1530 		 * Currently we limit it to one page.
1531 		 */
1532 		s32 offset;
1533 		sector_t bb_sector;
1534 		u64 *bbp;
1535 		int i;
1536 		int sectors = le16_to_cpu(sb->bblog_size);
1537 		if (sectors > (PAGE_SIZE / 512))
1538 			return -EINVAL;
1539 		offset = le32_to_cpu(sb->bblog_offset);
1540 		if (offset == 0)
1541 			return -EINVAL;
1542 		bb_sector = (long long)offset;
1543 		if (!sync_page_io(rdev, bb_sector, sectors << 9,
1544 				  rdev->bb_page, READ, true))
1545 			return -EIO;
1546 		bbp = (u64 *)page_address(rdev->bb_page);
1547 		rdev->badblocks.shift = sb->bblog_shift;
1548 		for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1549 			u64 bb = le64_to_cpu(*bbp);
1550 			int count = bb & (0x3ff);
1551 			u64 sector = bb >> 10;
1552 			sector <<= sb->bblog_shift;
1553 			count <<= sb->bblog_shift;
1554 			if (bb + 1 == 0)
1555 				break;
1556 			if (md_set_badblocks(&rdev->badblocks,
1557 					     sector, count, 1) == 0)
1558 				return -EINVAL;
1559 		}
1560 	} else if (sb->bblog_offset == 0)
1561 		rdev->badblocks.shift = -1;
1562 
1563 	if (!refdev) {
1564 		ret = 1;
1565 	} else {
1566 		__u64 ev1, ev2;
1567 		struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1568 
1569 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1570 		    sb->level != refsb->level ||
1571 		    sb->layout != refsb->layout ||
1572 		    sb->chunksize != refsb->chunksize) {
1573 			printk(KERN_WARNING "md: %s has strangely different"
1574 				" superblock to %s\n",
1575 				bdevname(rdev->bdev,b),
1576 				bdevname(refdev->bdev,b2));
1577 			return -EINVAL;
1578 		}
1579 		ev1 = le64_to_cpu(sb->events);
1580 		ev2 = le64_to_cpu(refsb->events);
1581 
1582 		if (ev1 > ev2)
1583 			ret = 1;
1584 		else
1585 			ret = 0;
1586 	}
1587 	if (minor_version) {
1588 		sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1589 		sectors -= rdev->data_offset;
1590 	} else
1591 		sectors = rdev->sb_start;
1592 	if (sectors < le64_to_cpu(sb->data_size))
1593 		return -EINVAL;
1594 	rdev->sectors = le64_to_cpu(sb->data_size);
1595 	return ret;
1596 }
1597 
1598 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1599 {
1600 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1601 	__u64 ev1 = le64_to_cpu(sb->events);
1602 
1603 	rdev->raid_disk = -1;
1604 	clear_bit(Faulty, &rdev->flags);
1605 	clear_bit(In_sync, &rdev->flags);
1606 	clear_bit(WriteMostly, &rdev->flags);
1607 
1608 	if (mddev->raid_disks == 0) {
1609 		mddev->major_version = 1;
1610 		mddev->patch_version = 0;
1611 		mddev->external = 0;
1612 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1613 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1614 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1615 		mddev->level = le32_to_cpu(sb->level);
1616 		mddev->clevel[0] = 0;
1617 		mddev->layout = le32_to_cpu(sb->layout);
1618 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1619 		mddev->dev_sectors = le64_to_cpu(sb->size);
1620 		mddev->events = ev1;
1621 		mddev->bitmap_info.offset = 0;
1622 		mddev->bitmap_info.space = 0;
1623 		/* Default location for bitmap is 1K after superblock
1624 		 * using 3K - total of 4K
1625 		 */
1626 		mddev->bitmap_info.default_offset = 1024 >> 9;
1627 		mddev->bitmap_info.default_space = (4096-1024) >> 9;
1628 		mddev->reshape_backwards = 0;
1629 
1630 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1631 		memcpy(mddev->uuid, sb->set_uuid, 16);
1632 
1633 		mddev->max_disks =  (4096-256)/2;
1634 
1635 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1636 		    mddev->bitmap_info.file == NULL) {
1637 			mddev->bitmap_info.offset =
1638 				(__s32)le32_to_cpu(sb->bitmap_offset);
1639 			/* Metadata doesn't record how much space is available.
1640 			 * For 1.0, we assume we can use up to the superblock
1641 			 * if before, else to 4K beyond superblock.
1642 			 * For others, assume no change is possible.
1643 			 */
1644 			if (mddev->minor_version > 0)
1645 				mddev->bitmap_info.space = 0;
1646 			else if (mddev->bitmap_info.offset > 0)
1647 				mddev->bitmap_info.space =
1648 					8 - mddev->bitmap_info.offset;
1649 			else
1650 				mddev->bitmap_info.space =
1651 					-mddev->bitmap_info.offset;
1652 		}
1653 
1654 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1655 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1656 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1657 			mddev->new_level = le32_to_cpu(sb->new_level);
1658 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1659 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1660 			if (mddev->delta_disks < 0 ||
1661 			    (mddev->delta_disks == 0 &&
1662 			     (le32_to_cpu(sb->feature_map)
1663 			      & MD_FEATURE_RESHAPE_BACKWARDS)))
1664 				mddev->reshape_backwards = 1;
1665 		} else {
1666 			mddev->reshape_position = MaxSector;
1667 			mddev->delta_disks = 0;
1668 			mddev->new_level = mddev->level;
1669 			mddev->new_layout = mddev->layout;
1670 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1671 		}
1672 
1673 	} else if (mddev->pers == NULL) {
1674 		/* Insist of good event counter while assembling, except for
1675 		 * spares (which don't need an event count) */
1676 		++ev1;
1677 		if (rdev->desc_nr >= 0 &&
1678 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1679 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1680 			if (ev1 < mddev->events)
1681 				return -EINVAL;
1682 	} else if (mddev->bitmap) {
1683 		/* If adding to array with a bitmap, then we can accept an
1684 		 * older device, but not too old.
1685 		 */
1686 		if (ev1 < mddev->bitmap->events_cleared)
1687 			return 0;
1688 	} else {
1689 		if (ev1 < mddev->events)
1690 			/* just a hot-add of a new device, leave raid_disk at -1 */
1691 			return 0;
1692 	}
1693 	if (mddev->level != LEVEL_MULTIPATH) {
1694 		int role;
1695 		if (rdev->desc_nr < 0 ||
1696 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1697 			role = 0xffff;
1698 			rdev->desc_nr = -1;
1699 		} else
1700 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1701 		switch(role) {
1702 		case 0xffff: /* spare */
1703 			break;
1704 		case 0xfffe: /* faulty */
1705 			set_bit(Faulty, &rdev->flags);
1706 			break;
1707 		default:
1708 			if ((le32_to_cpu(sb->feature_map) &
1709 			     MD_FEATURE_RECOVERY_OFFSET))
1710 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1711 			else
1712 				set_bit(In_sync, &rdev->flags);
1713 			rdev->raid_disk = role;
1714 			break;
1715 		}
1716 		if (sb->devflags & WriteMostly1)
1717 			set_bit(WriteMostly, &rdev->flags);
1718 		if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1719 			set_bit(Replacement, &rdev->flags);
1720 	} else /* MULTIPATH are always insync */
1721 		set_bit(In_sync, &rdev->flags);
1722 
1723 	return 0;
1724 }
1725 
1726 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1727 {
1728 	struct mdp_superblock_1 *sb;
1729 	struct md_rdev *rdev2;
1730 	int max_dev, i;
1731 	/* make rdev->sb match mddev and rdev data. */
1732 
1733 	sb = page_address(rdev->sb_page);
1734 
1735 	sb->feature_map = 0;
1736 	sb->pad0 = 0;
1737 	sb->recovery_offset = cpu_to_le64(0);
1738 	memset(sb->pad3, 0, sizeof(sb->pad3));
1739 
1740 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1741 	sb->events = cpu_to_le64(mddev->events);
1742 	if (mddev->in_sync)
1743 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1744 	else
1745 		sb->resync_offset = cpu_to_le64(0);
1746 
1747 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1748 
1749 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1750 	sb->size = cpu_to_le64(mddev->dev_sectors);
1751 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1752 	sb->level = cpu_to_le32(mddev->level);
1753 	sb->layout = cpu_to_le32(mddev->layout);
1754 
1755 	if (test_bit(WriteMostly, &rdev->flags))
1756 		sb->devflags |= WriteMostly1;
1757 	else
1758 		sb->devflags &= ~WriteMostly1;
1759 	sb->data_offset = cpu_to_le64(rdev->data_offset);
1760 	sb->data_size = cpu_to_le64(rdev->sectors);
1761 
1762 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1763 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1764 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1765 	}
1766 
1767 	if (rdev->raid_disk >= 0 &&
1768 	    !test_bit(In_sync, &rdev->flags)) {
1769 		sb->feature_map |=
1770 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1771 		sb->recovery_offset =
1772 			cpu_to_le64(rdev->recovery_offset);
1773 	}
1774 	if (test_bit(Replacement, &rdev->flags))
1775 		sb->feature_map |=
1776 			cpu_to_le32(MD_FEATURE_REPLACEMENT);
1777 
1778 	if (mddev->reshape_position != MaxSector) {
1779 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1780 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1781 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1782 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1783 		sb->new_level = cpu_to_le32(mddev->new_level);
1784 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1785 		if (mddev->delta_disks == 0 &&
1786 		    mddev->reshape_backwards)
1787 			sb->feature_map
1788 				|= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1789 		if (rdev->new_data_offset != rdev->data_offset) {
1790 			sb->feature_map
1791 				|= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1792 			sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1793 							     - rdev->data_offset));
1794 		}
1795 	}
1796 
1797 	if (rdev->badblocks.count == 0)
1798 		/* Nothing to do for bad blocks*/ ;
1799 	else if (sb->bblog_offset == 0)
1800 		/* Cannot record bad blocks on this device */
1801 		md_error(mddev, rdev);
1802 	else {
1803 		struct badblocks *bb = &rdev->badblocks;
1804 		u64 *bbp = (u64 *)page_address(rdev->bb_page);
1805 		u64 *p = bb->page;
1806 		sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1807 		if (bb->changed) {
1808 			unsigned seq;
1809 
1810 retry:
1811 			seq = read_seqbegin(&bb->lock);
1812 
1813 			memset(bbp, 0xff, PAGE_SIZE);
1814 
1815 			for (i = 0 ; i < bb->count ; i++) {
1816 				u64 internal_bb = *p++;
1817 				u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1818 						| BB_LEN(internal_bb));
1819 				*bbp++ = cpu_to_le64(store_bb);
1820 			}
1821 			bb->changed = 0;
1822 			if (read_seqretry(&bb->lock, seq))
1823 				goto retry;
1824 
1825 			bb->sector = (rdev->sb_start +
1826 				      (int)le32_to_cpu(sb->bblog_offset));
1827 			bb->size = le16_to_cpu(sb->bblog_size);
1828 		}
1829 	}
1830 
1831 	max_dev = 0;
1832 	rdev_for_each(rdev2, mddev)
1833 		if (rdev2->desc_nr+1 > max_dev)
1834 			max_dev = rdev2->desc_nr+1;
1835 
1836 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1837 		int bmask;
1838 		sb->max_dev = cpu_to_le32(max_dev);
1839 		rdev->sb_size = max_dev * 2 + 256;
1840 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1841 		if (rdev->sb_size & bmask)
1842 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1843 	} else
1844 		max_dev = le32_to_cpu(sb->max_dev);
1845 
1846 	for (i=0; i<max_dev;i++)
1847 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1848 
1849 	rdev_for_each(rdev2, mddev) {
1850 		i = rdev2->desc_nr;
1851 		if (test_bit(Faulty, &rdev2->flags))
1852 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1853 		else if (test_bit(In_sync, &rdev2->flags))
1854 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1855 		else if (rdev2->raid_disk >= 0)
1856 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1857 		else
1858 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1859 	}
1860 
1861 	sb->sb_csum = calc_sb_1_csum(sb);
1862 }
1863 
1864 static unsigned long long
1865 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1866 {
1867 	struct mdp_superblock_1 *sb;
1868 	sector_t max_sectors;
1869 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1870 		return 0; /* component must fit device */
1871 	if (rdev->data_offset != rdev->new_data_offset)
1872 		return 0; /* too confusing */
1873 	if (rdev->sb_start < rdev->data_offset) {
1874 		/* minor versions 1 and 2; superblock before data */
1875 		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1876 		max_sectors -= rdev->data_offset;
1877 		if (!num_sectors || num_sectors > max_sectors)
1878 			num_sectors = max_sectors;
1879 	} else if (rdev->mddev->bitmap_info.offset) {
1880 		/* minor version 0 with bitmap we can't move */
1881 		return 0;
1882 	} else {
1883 		/* minor version 0; superblock after data */
1884 		sector_t sb_start;
1885 		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1886 		sb_start &= ~(sector_t)(4*2 - 1);
1887 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1888 		if (!num_sectors || num_sectors > max_sectors)
1889 			num_sectors = max_sectors;
1890 		rdev->sb_start = sb_start;
1891 	}
1892 	sb = page_address(rdev->sb_page);
1893 	sb->data_size = cpu_to_le64(num_sectors);
1894 	sb->super_offset = rdev->sb_start;
1895 	sb->sb_csum = calc_sb_1_csum(sb);
1896 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1897 		       rdev->sb_page);
1898 	md_super_wait(rdev->mddev);
1899 	return num_sectors;
1900 
1901 }
1902 
1903 static int
1904 super_1_allow_new_offset(struct md_rdev *rdev,
1905 			 unsigned long long new_offset)
1906 {
1907 	/* All necessary checks on new >= old have been done */
1908 	struct bitmap *bitmap;
1909 	if (new_offset >= rdev->data_offset)
1910 		return 1;
1911 
1912 	/* with 1.0 metadata, there is no metadata to tread on
1913 	 * so we can always move back */
1914 	if (rdev->mddev->minor_version == 0)
1915 		return 1;
1916 
1917 	/* otherwise we must be sure not to step on
1918 	 * any metadata, so stay:
1919 	 * 36K beyond start of superblock
1920 	 * beyond end of badblocks
1921 	 * beyond write-intent bitmap
1922 	 */
1923 	if (rdev->sb_start + (32+4)*2 > new_offset)
1924 		return 0;
1925 	bitmap = rdev->mddev->bitmap;
1926 	if (bitmap && !rdev->mddev->bitmap_info.file &&
1927 	    rdev->sb_start + rdev->mddev->bitmap_info.offset +
1928 	    bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1929 		return 0;
1930 	if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1931 		return 0;
1932 
1933 	return 1;
1934 }
1935 
1936 static struct super_type super_types[] = {
1937 	[0] = {
1938 		.name	= "0.90.0",
1939 		.owner	= THIS_MODULE,
1940 		.load_super	    = super_90_load,
1941 		.validate_super	    = super_90_validate,
1942 		.sync_super	    = super_90_sync,
1943 		.rdev_size_change   = super_90_rdev_size_change,
1944 		.allow_new_offset   = super_90_allow_new_offset,
1945 	},
1946 	[1] = {
1947 		.name	= "md-1",
1948 		.owner	= THIS_MODULE,
1949 		.load_super	    = super_1_load,
1950 		.validate_super	    = super_1_validate,
1951 		.sync_super	    = super_1_sync,
1952 		.rdev_size_change   = super_1_rdev_size_change,
1953 		.allow_new_offset   = super_1_allow_new_offset,
1954 	},
1955 };
1956 
1957 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1958 {
1959 	if (mddev->sync_super) {
1960 		mddev->sync_super(mddev, rdev);
1961 		return;
1962 	}
1963 
1964 	BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1965 
1966 	super_types[mddev->major_version].sync_super(mddev, rdev);
1967 }
1968 
1969 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1970 {
1971 	struct md_rdev *rdev, *rdev2;
1972 
1973 	rcu_read_lock();
1974 	rdev_for_each_rcu(rdev, mddev1)
1975 		rdev_for_each_rcu(rdev2, mddev2)
1976 			if (rdev->bdev->bd_contains ==
1977 			    rdev2->bdev->bd_contains) {
1978 				rcu_read_unlock();
1979 				return 1;
1980 			}
1981 	rcu_read_unlock();
1982 	return 0;
1983 }
1984 
1985 static LIST_HEAD(pending_raid_disks);
1986 
1987 /*
1988  * Try to register data integrity profile for an mddev
1989  *
1990  * This is called when an array is started and after a disk has been kicked
1991  * from the array. It only succeeds if all working and active component devices
1992  * are integrity capable with matching profiles.
1993  */
1994 int md_integrity_register(struct mddev *mddev)
1995 {
1996 	struct md_rdev *rdev, *reference = NULL;
1997 
1998 	if (list_empty(&mddev->disks))
1999 		return 0; /* nothing to do */
2000 	if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
2001 		return 0; /* shouldn't register, or already is */
2002 	rdev_for_each(rdev, mddev) {
2003 		/* skip spares and non-functional disks */
2004 		if (test_bit(Faulty, &rdev->flags))
2005 			continue;
2006 		if (rdev->raid_disk < 0)
2007 			continue;
2008 		if (!reference) {
2009 			/* Use the first rdev as the reference */
2010 			reference = rdev;
2011 			continue;
2012 		}
2013 		/* does this rdev's profile match the reference profile? */
2014 		if (blk_integrity_compare(reference->bdev->bd_disk,
2015 				rdev->bdev->bd_disk) < 0)
2016 			return -EINVAL;
2017 	}
2018 	if (!reference || !bdev_get_integrity(reference->bdev))
2019 		return 0;
2020 	/*
2021 	 * All component devices are integrity capable and have matching
2022 	 * profiles, register the common profile for the md device.
2023 	 */
2024 	if (blk_integrity_register(mddev->gendisk,
2025 			bdev_get_integrity(reference->bdev)) != 0) {
2026 		printk(KERN_ERR "md: failed to register integrity for %s\n",
2027 			mdname(mddev));
2028 		return -EINVAL;
2029 	}
2030 	printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2031 	if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2032 		printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2033 		       mdname(mddev));
2034 		return -EINVAL;
2035 	}
2036 	return 0;
2037 }
2038 EXPORT_SYMBOL(md_integrity_register);
2039 
2040 /* Disable data integrity if non-capable/non-matching disk is being added */
2041 void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2042 {
2043 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
2044 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
2045 
2046 	if (!bi_mddev) /* nothing to do */
2047 		return;
2048 	if (rdev->raid_disk < 0) /* skip spares */
2049 		return;
2050 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
2051 					     rdev->bdev->bd_disk) >= 0)
2052 		return;
2053 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
2054 	blk_integrity_unregister(mddev->gendisk);
2055 }
2056 EXPORT_SYMBOL(md_integrity_add_rdev);
2057 
2058 static int bind_rdev_to_array(struct md_rdev * rdev, struct mddev * mddev)
2059 {
2060 	char b[BDEVNAME_SIZE];
2061 	struct kobject *ko;
2062 	char *s;
2063 	int err;
2064 
2065 	if (rdev->mddev) {
2066 		MD_BUG();
2067 		return -EINVAL;
2068 	}
2069 
2070 	/* prevent duplicates */
2071 	if (find_rdev(mddev, rdev->bdev->bd_dev))
2072 		return -EEXIST;
2073 
2074 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
2075 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
2076 			rdev->sectors < mddev->dev_sectors)) {
2077 		if (mddev->pers) {
2078 			/* Cannot change size, so fail
2079 			 * If mddev->level <= 0, then we don't care
2080 			 * about aligning sizes (e.g. linear)
2081 			 */
2082 			if (mddev->level > 0)
2083 				return -ENOSPC;
2084 		} else
2085 			mddev->dev_sectors = rdev->sectors;
2086 	}
2087 
2088 	/* Verify rdev->desc_nr is unique.
2089 	 * If it is -1, assign a free number, else
2090 	 * check number is not in use
2091 	 */
2092 	if (rdev->desc_nr < 0) {
2093 		int choice = 0;
2094 		if (mddev->pers) choice = mddev->raid_disks;
2095 		while (find_rdev_nr(mddev, choice))
2096 			choice++;
2097 		rdev->desc_nr = choice;
2098 	} else {
2099 		if (find_rdev_nr(mddev, rdev->desc_nr))
2100 			return -EBUSY;
2101 	}
2102 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2103 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2104 		       mdname(mddev), mddev->max_disks);
2105 		return -EBUSY;
2106 	}
2107 	bdevname(rdev->bdev,b);
2108 	while ( (s=strchr(b, '/')) != NULL)
2109 		*s = '!';
2110 
2111 	rdev->mddev = mddev;
2112 	printk(KERN_INFO "md: bind<%s>\n", b);
2113 
2114 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2115 		goto fail;
2116 
2117 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2118 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
2119 		/* failure here is OK */;
2120 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2121 
2122 	list_add_rcu(&rdev->same_set, &mddev->disks);
2123 	bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2124 
2125 	/* May as well allow recovery to be retried once */
2126 	mddev->recovery_disabled++;
2127 
2128 	return 0;
2129 
2130  fail:
2131 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2132 	       b, mdname(mddev));
2133 	return err;
2134 }
2135 
2136 static void md_delayed_delete(struct work_struct *ws)
2137 {
2138 	struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2139 	kobject_del(&rdev->kobj);
2140 	kobject_put(&rdev->kobj);
2141 }
2142 
2143 static void unbind_rdev_from_array(struct md_rdev * rdev)
2144 {
2145 	char b[BDEVNAME_SIZE];
2146 	if (!rdev->mddev) {
2147 		MD_BUG();
2148 		return;
2149 	}
2150 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2151 	list_del_rcu(&rdev->same_set);
2152 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2153 	rdev->mddev = NULL;
2154 	sysfs_remove_link(&rdev->kobj, "block");
2155 	sysfs_put(rdev->sysfs_state);
2156 	rdev->sysfs_state = NULL;
2157 	rdev->badblocks.count = 0;
2158 	/* We need to delay this, otherwise we can deadlock when
2159 	 * writing to 'remove' to "dev/state".  We also need
2160 	 * to delay it due to rcu usage.
2161 	 */
2162 	synchronize_rcu();
2163 	INIT_WORK(&rdev->del_work, md_delayed_delete);
2164 	kobject_get(&rdev->kobj);
2165 	queue_work(md_misc_wq, &rdev->del_work);
2166 }
2167 
2168 /*
2169  * prevent the device from being mounted, repartitioned or
2170  * otherwise reused by a RAID array (or any other kernel
2171  * subsystem), by bd_claiming the device.
2172  */
2173 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2174 {
2175 	int err = 0;
2176 	struct block_device *bdev;
2177 	char b[BDEVNAME_SIZE];
2178 
2179 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2180 				 shared ? (struct md_rdev *)lock_rdev : rdev);
2181 	if (IS_ERR(bdev)) {
2182 		printk(KERN_ERR "md: could not open %s.\n",
2183 			__bdevname(dev, b));
2184 		return PTR_ERR(bdev);
2185 	}
2186 	rdev->bdev = bdev;
2187 	return err;
2188 }
2189 
2190 static void unlock_rdev(struct md_rdev *rdev)
2191 {
2192 	struct block_device *bdev = rdev->bdev;
2193 	rdev->bdev = NULL;
2194 	if (!bdev)
2195 		MD_BUG();
2196 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2197 }
2198 
2199 void md_autodetect_dev(dev_t dev);
2200 
2201 static void export_rdev(struct md_rdev * rdev)
2202 {
2203 	char b[BDEVNAME_SIZE];
2204 	printk(KERN_INFO "md: export_rdev(%s)\n",
2205 		bdevname(rdev->bdev,b));
2206 	if (rdev->mddev)
2207 		MD_BUG();
2208 	md_rdev_clear(rdev);
2209 #ifndef MODULE
2210 	if (test_bit(AutoDetected, &rdev->flags))
2211 		md_autodetect_dev(rdev->bdev->bd_dev);
2212 #endif
2213 	unlock_rdev(rdev);
2214 	kobject_put(&rdev->kobj);
2215 }
2216 
2217 static void kick_rdev_from_array(struct md_rdev * rdev)
2218 {
2219 	unbind_rdev_from_array(rdev);
2220 	export_rdev(rdev);
2221 }
2222 
2223 static void export_array(struct mddev *mddev)
2224 {
2225 	struct md_rdev *rdev, *tmp;
2226 
2227 	rdev_for_each_safe(rdev, tmp, mddev) {
2228 		if (!rdev->mddev) {
2229 			MD_BUG();
2230 			continue;
2231 		}
2232 		kick_rdev_from_array(rdev);
2233 	}
2234 	if (!list_empty(&mddev->disks))
2235 		MD_BUG();
2236 	mddev->raid_disks = 0;
2237 	mddev->major_version = 0;
2238 }
2239 
2240 static void print_desc(mdp_disk_t *desc)
2241 {
2242 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2243 		desc->major,desc->minor,desc->raid_disk,desc->state);
2244 }
2245 
2246 static void print_sb_90(mdp_super_t *sb)
2247 {
2248 	int i;
2249 
2250 	printk(KERN_INFO
2251 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2252 		sb->major_version, sb->minor_version, sb->patch_version,
2253 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2254 		sb->ctime);
2255 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2256 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2257 		sb->md_minor, sb->layout, sb->chunk_size);
2258 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2259 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2260 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2261 		sb->failed_disks, sb->spare_disks,
2262 		sb->sb_csum, (unsigned long)sb->events_lo);
2263 
2264 	printk(KERN_INFO);
2265 	for (i = 0; i < MD_SB_DISKS; i++) {
2266 		mdp_disk_t *desc;
2267 
2268 		desc = sb->disks + i;
2269 		if (desc->number || desc->major || desc->minor ||
2270 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2271 			printk("     D %2d: ", i);
2272 			print_desc(desc);
2273 		}
2274 	}
2275 	printk(KERN_INFO "md:     THIS: ");
2276 	print_desc(&sb->this_disk);
2277 }
2278 
2279 static void print_sb_1(struct mdp_superblock_1 *sb)
2280 {
2281 	__u8 *uuid;
2282 
2283 	uuid = sb->set_uuid;
2284 	printk(KERN_INFO
2285 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2286 	       "md:    Name: \"%s\" CT:%llu\n",
2287 		le32_to_cpu(sb->major_version),
2288 		le32_to_cpu(sb->feature_map),
2289 		uuid,
2290 		sb->set_name,
2291 		(unsigned long long)le64_to_cpu(sb->ctime)
2292 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2293 
2294 	uuid = sb->device_uuid;
2295 	printk(KERN_INFO
2296 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2297 			" RO:%llu\n"
2298 	       "md:     Dev:%08x UUID: %pU\n"
2299 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2300 	       "md:         (MaxDev:%u) \n",
2301 		le32_to_cpu(sb->level),
2302 		(unsigned long long)le64_to_cpu(sb->size),
2303 		le32_to_cpu(sb->raid_disks),
2304 		le32_to_cpu(sb->layout),
2305 		le32_to_cpu(sb->chunksize),
2306 		(unsigned long long)le64_to_cpu(sb->data_offset),
2307 		(unsigned long long)le64_to_cpu(sb->data_size),
2308 		(unsigned long long)le64_to_cpu(sb->super_offset),
2309 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2310 		le32_to_cpu(sb->dev_number),
2311 		uuid,
2312 		sb->devflags,
2313 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2314 		(unsigned long long)le64_to_cpu(sb->events),
2315 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2316 		le32_to_cpu(sb->sb_csum),
2317 		le32_to_cpu(sb->max_dev)
2318 		);
2319 }
2320 
2321 static void print_rdev(struct md_rdev *rdev, int major_version)
2322 {
2323 	char b[BDEVNAME_SIZE];
2324 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2325 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2326 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2327 	        rdev->desc_nr);
2328 	if (rdev->sb_loaded) {
2329 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2330 		switch (major_version) {
2331 		case 0:
2332 			print_sb_90(page_address(rdev->sb_page));
2333 			break;
2334 		case 1:
2335 			print_sb_1(page_address(rdev->sb_page));
2336 			break;
2337 		}
2338 	} else
2339 		printk(KERN_INFO "md: no rdev superblock!\n");
2340 }
2341 
2342 static void md_print_devices(void)
2343 {
2344 	struct list_head *tmp;
2345 	struct md_rdev *rdev;
2346 	struct mddev *mddev;
2347 	char b[BDEVNAME_SIZE];
2348 
2349 	printk("\n");
2350 	printk("md:	**********************************\n");
2351 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2352 	printk("md:	**********************************\n");
2353 	for_each_mddev(mddev, tmp) {
2354 
2355 		if (mddev->bitmap)
2356 			bitmap_print_sb(mddev->bitmap);
2357 		else
2358 			printk("%s: ", mdname(mddev));
2359 		rdev_for_each(rdev, mddev)
2360 			printk("<%s>", bdevname(rdev->bdev,b));
2361 		printk("\n");
2362 
2363 		rdev_for_each(rdev, mddev)
2364 			print_rdev(rdev, mddev->major_version);
2365 	}
2366 	printk("md:	**********************************\n");
2367 	printk("\n");
2368 }
2369 
2370 
2371 static void sync_sbs(struct mddev * mddev, int nospares)
2372 {
2373 	/* Update each superblock (in-memory image), but
2374 	 * if we are allowed to, skip spares which already
2375 	 * have the right event counter, or have one earlier
2376 	 * (which would mean they aren't being marked as dirty
2377 	 * with the rest of the array)
2378 	 */
2379 	struct md_rdev *rdev;
2380 	rdev_for_each(rdev, mddev) {
2381 		if (rdev->sb_events == mddev->events ||
2382 		    (nospares &&
2383 		     rdev->raid_disk < 0 &&
2384 		     rdev->sb_events+1 == mddev->events)) {
2385 			/* Don't update this superblock */
2386 			rdev->sb_loaded = 2;
2387 		} else {
2388 			sync_super(mddev, rdev);
2389 			rdev->sb_loaded = 1;
2390 		}
2391 	}
2392 }
2393 
2394 static void md_update_sb(struct mddev * mddev, int force_change)
2395 {
2396 	struct md_rdev *rdev;
2397 	int sync_req;
2398 	int nospares = 0;
2399 	int any_badblocks_changed = 0;
2400 
2401 repeat:
2402 	/* First make sure individual recovery_offsets are correct */
2403 	rdev_for_each(rdev, mddev) {
2404 		if (rdev->raid_disk >= 0 &&
2405 		    mddev->delta_disks >= 0 &&
2406 		    !test_bit(In_sync, &rdev->flags) &&
2407 		    mddev->curr_resync_completed > rdev->recovery_offset)
2408 				rdev->recovery_offset = mddev->curr_resync_completed;
2409 
2410 	}
2411 	if (!mddev->persistent) {
2412 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2413 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2414 		if (!mddev->external) {
2415 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2416 			rdev_for_each(rdev, mddev) {
2417 				if (rdev->badblocks.changed) {
2418 					rdev->badblocks.changed = 0;
2419 					md_ack_all_badblocks(&rdev->badblocks);
2420 					md_error(mddev, rdev);
2421 				}
2422 				clear_bit(Blocked, &rdev->flags);
2423 				clear_bit(BlockedBadBlocks, &rdev->flags);
2424 				wake_up(&rdev->blocked_wait);
2425 			}
2426 		}
2427 		wake_up(&mddev->sb_wait);
2428 		return;
2429 	}
2430 
2431 	spin_lock_irq(&mddev->write_lock);
2432 
2433 	mddev->utime = get_seconds();
2434 
2435 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2436 		force_change = 1;
2437 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2438 		/* just a clean<-> dirty transition, possibly leave spares alone,
2439 		 * though if events isn't the right even/odd, we will have to do
2440 		 * spares after all
2441 		 */
2442 		nospares = 1;
2443 	if (force_change)
2444 		nospares = 0;
2445 	if (mddev->degraded)
2446 		/* If the array is degraded, then skipping spares is both
2447 		 * dangerous and fairly pointless.
2448 		 * Dangerous because a device that was removed from the array
2449 		 * might have a event_count that still looks up-to-date,
2450 		 * so it can be re-added without a resync.
2451 		 * Pointless because if there are any spares to skip,
2452 		 * then a recovery will happen and soon that array won't
2453 		 * be degraded any more and the spare can go back to sleep then.
2454 		 */
2455 		nospares = 0;
2456 
2457 	sync_req = mddev->in_sync;
2458 
2459 	/* If this is just a dirty<->clean transition, and the array is clean
2460 	 * and 'events' is odd, we can roll back to the previous clean state */
2461 	if (nospares
2462 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2463 	    && mddev->can_decrease_events
2464 	    && mddev->events != 1) {
2465 		mddev->events--;
2466 		mddev->can_decrease_events = 0;
2467 	} else {
2468 		/* otherwise we have to go forward and ... */
2469 		mddev->events ++;
2470 		mddev->can_decrease_events = nospares;
2471 	}
2472 
2473 	if (!mddev->events) {
2474 		/*
2475 		 * oops, this 64-bit counter should never wrap.
2476 		 * Either we are in around ~1 trillion A.C., assuming
2477 		 * 1 reboot per second, or we have a bug:
2478 		 */
2479 		MD_BUG();
2480 		mddev->events --;
2481 	}
2482 
2483 	rdev_for_each(rdev, mddev) {
2484 		if (rdev->badblocks.changed)
2485 			any_badblocks_changed++;
2486 		if (test_bit(Faulty, &rdev->flags))
2487 			set_bit(FaultRecorded, &rdev->flags);
2488 	}
2489 
2490 	sync_sbs(mddev, nospares);
2491 	spin_unlock_irq(&mddev->write_lock);
2492 
2493 	pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2494 		 mdname(mddev), mddev->in_sync);
2495 
2496 	bitmap_update_sb(mddev->bitmap);
2497 	rdev_for_each(rdev, mddev) {
2498 		char b[BDEVNAME_SIZE];
2499 
2500 		if (rdev->sb_loaded != 1)
2501 			continue; /* no noise on spare devices */
2502 
2503 		if (!test_bit(Faulty, &rdev->flags) &&
2504 		    rdev->saved_raid_disk == -1) {
2505 			md_super_write(mddev,rdev,
2506 				       rdev->sb_start, rdev->sb_size,
2507 				       rdev->sb_page);
2508 			pr_debug("md: (write) %s's sb offset: %llu\n",
2509 				 bdevname(rdev->bdev, b),
2510 				 (unsigned long long)rdev->sb_start);
2511 			rdev->sb_events = mddev->events;
2512 			if (rdev->badblocks.size) {
2513 				md_super_write(mddev, rdev,
2514 					       rdev->badblocks.sector,
2515 					       rdev->badblocks.size << 9,
2516 					       rdev->bb_page);
2517 				rdev->badblocks.size = 0;
2518 			}
2519 
2520 		} else if (test_bit(Faulty, &rdev->flags))
2521 			pr_debug("md: %s (skipping faulty)\n",
2522 				 bdevname(rdev->bdev, b));
2523 		else
2524 			pr_debug("(skipping incremental s/r ");
2525 
2526 		if (mddev->level == LEVEL_MULTIPATH)
2527 			/* only need to write one superblock... */
2528 			break;
2529 	}
2530 	md_super_wait(mddev);
2531 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2532 
2533 	spin_lock_irq(&mddev->write_lock);
2534 	if (mddev->in_sync != sync_req ||
2535 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2536 		/* have to write it out again */
2537 		spin_unlock_irq(&mddev->write_lock);
2538 		goto repeat;
2539 	}
2540 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2541 	spin_unlock_irq(&mddev->write_lock);
2542 	wake_up(&mddev->sb_wait);
2543 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2544 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2545 
2546 	rdev_for_each(rdev, mddev) {
2547 		if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2548 			clear_bit(Blocked, &rdev->flags);
2549 
2550 		if (any_badblocks_changed)
2551 			md_ack_all_badblocks(&rdev->badblocks);
2552 		clear_bit(BlockedBadBlocks, &rdev->flags);
2553 		wake_up(&rdev->blocked_wait);
2554 	}
2555 }
2556 
2557 /* words written to sysfs files may, or may not, be \n terminated.
2558  * We want to accept with case. For this we use cmd_match.
2559  */
2560 static int cmd_match(const char *cmd, const char *str)
2561 {
2562 	/* See if cmd, written into a sysfs file, matches
2563 	 * str.  They must either be the same, or cmd can
2564 	 * have a trailing newline
2565 	 */
2566 	while (*cmd && *str && *cmd == *str) {
2567 		cmd++;
2568 		str++;
2569 	}
2570 	if (*cmd == '\n')
2571 		cmd++;
2572 	if (*str || *cmd)
2573 		return 0;
2574 	return 1;
2575 }
2576 
2577 struct rdev_sysfs_entry {
2578 	struct attribute attr;
2579 	ssize_t (*show)(struct md_rdev *, char *);
2580 	ssize_t (*store)(struct md_rdev *, const char *, size_t);
2581 };
2582 
2583 static ssize_t
2584 state_show(struct md_rdev *rdev, char *page)
2585 {
2586 	char *sep = "";
2587 	size_t len = 0;
2588 
2589 	if (test_bit(Faulty, &rdev->flags) ||
2590 	    rdev->badblocks.unacked_exist) {
2591 		len+= sprintf(page+len, "%sfaulty",sep);
2592 		sep = ",";
2593 	}
2594 	if (test_bit(In_sync, &rdev->flags)) {
2595 		len += sprintf(page+len, "%sin_sync",sep);
2596 		sep = ",";
2597 	}
2598 	if (test_bit(WriteMostly, &rdev->flags)) {
2599 		len += sprintf(page+len, "%swrite_mostly",sep);
2600 		sep = ",";
2601 	}
2602 	if (test_bit(Blocked, &rdev->flags) ||
2603 	    (rdev->badblocks.unacked_exist
2604 	     && !test_bit(Faulty, &rdev->flags))) {
2605 		len += sprintf(page+len, "%sblocked", sep);
2606 		sep = ",";
2607 	}
2608 	if (!test_bit(Faulty, &rdev->flags) &&
2609 	    !test_bit(In_sync, &rdev->flags)) {
2610 		len += sprintf(page+len, "%sspare", sep);
2611 		sep = ",";
2612 	}
2613 	if (test_bit(WriteErrorSeen, &rdev->flags)) {
2614 		len += sprintf(page+len, "%swrite_error", sep);
2615 		sep = ",";
2616 	}
2617 	if (test_bit(WantReplacement, &rdev->flags)) {
2618 		len += sprintf(page+len, "%swant_replacement", sep);
2619 		sep = ",";
2620 	}
2621 	if (test_bit(Replacement, &rdev->flags)) {
2622 		len += sprintf(page+len, "%sreplacement", sep);
2623 		sep = ",";
2624 	}
2625 
2626 	return len+sprintf(page+len, "\n");
2627 }
2628 
2629 static ssize_t
2630 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2631 {
2632 	/* can write
2633 	 *  faulty  - simulates an error
2634 	 *  remove  - disconnects the device
2635 	 *  writemostly - sets write_mostly
2636 	 *  -writemostly - clears write_mostly
2637 	 *  blocked - sets the Blocked flags
2638 	 *  -blocked - clears the Blocked and possibly simulates an error
2639 	 *  insync - sets Insync providing device isn't active
2640 	 *  write_error - sets WriteErrorSeen
2641 	 *  -write_error - clears WriteErrorSeen
2642 	 */
2643 	int err = -EINVAL;
2644 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2645 		md_error(rdev->mddev, rdev);
2646 		if (test_bit(Faulty, &rdev->flags))
2647 			err = 0;
2648 		else
2649 			err = -EBUSY;
2650 	} else if (cmd_match(buf, "remove")) {
2651 		if (rdev->raid_disk >= 0)
2652 			err = -EBUSY;
2653 		else {
2654 			struct mddev *mddev = rdev->mddev;
2655 			kick_rdev_from_array(rdev);
2656 			if (mddev->pers)
2657 				md_update_sb(mddev, 1);
2658 			md_new_event(mddev);
2659 			err = 0;
2660 		}
2661 	} else if (cmd_match(buf, "writemostly")) {
2662 		set_bit(WriteMostly, &rdev->flags);
2663 		err = 0;
2664 	} else if (cmd_match(buf, "-writemostly")) {
2665 		clear_bit(WriteMostly, &rdev->flags);
2666 		err = 0;
2667 	} else if (cmd_match(buf, "blocked")) {
2668 		set_bit(Blocked, &rdev->flags);
2669 		err = 0;
2670 	} else if (cmd_match(buf, "-blocked")) {
2671 		if (!test_bit(Faulty, &rdev->flags) &&
2672 		    rdev->badblocks.unacked_exist) {
2673 			/* metadata handler doesn't understand badblocks,
2674 			 * so we need to fail the device
2675 			 */
2676 			md_error(rdev->mddev, rdev);
2677 		}
2678 		clear_bit(Blocked, &rdev->flags);
2679 		clear_bit(BlockedBadBlocks, &rdev->flags);
2680 		wake_up(&rdev->blocked_wait);
2681 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2682 		md_wakeup_thread(rdev->mddev->thread);
2683 
2684 		err = 0;
2685 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2686 		set_bit(In_sync, &rdev->flags);
2687 		err = 0;
2688 	} else if (cmd_match(buf, "write_error")) {
2689 		set_bit(WriteErrorSeen, &rdev->flags);
2690 		err = 0;
2691 	} else if (cmd_match(buf, "-write_error")) {
2692 		clear_bit(WriteErrorSeen, &rdev->flags);
2693 		err = 0;
2694 	} else if (cmd_match(buf, "want_replacement")) {
2695 		/* Any non-spare device that is not a replacement can
2696 		 * become want_replacement at any time, but we then need to
2697 		 * check if recovery is needed.
2698 		 */
2699 		if (rdev->raid_disk >= 0 &&
2700 		    !test_bit(Replacement, &rdev->flags))
2701 			set_bit(WantReplacement, &rdev->flags);
2702 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2703 		md_wakeup_thread(rdev->mddev->thread);
2704 		err = 0;
2705 	} else if (cmd_match(buf, "-want_replacement")) {
2706 		/* Clearing 'want_replacement' is always allowed.
2707 		 * Once replacements starts it is too late though.
2708 		 */
2709 		err = 0;
2710 		clear_bit(WantReplacement, &rdev->flags);
2711 	} else if (cmd_match(buf, "replacement")) {
2712 		/* Can only set a device as a replacement when array has not
2713 		 * yet been started.  Once running, replacement is automatic
2714 		 * from spares, or by assigning 'slot'.
2715 		 */
2716 		if (rdev->mddev->pers)
2717 			err = -EBUSY;
2718 		else {
2719 			set_bit(Replacement, &rdev->flags);
2720 			err = 0;
2721 		}
2722 	} else if (cmd_match(buf, "-replacement")) {
2723 		/* Similarly, can only clear Replacement before start */
2724 		if (rdev->mddev->pers)
2725 			err = -EBUSY;
2726 		else {
2727 			clear_bit(Replacement, &rdev->flags);
2728 			err = 0;
2729 		}
2730 	}
2731 	if (!err)
2732 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2733 	return err ? err : len;
2734 }
2735 static struct rdev_sysfs_entry rdev_state =
2736 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2737 
2738 static ssize_t
2739 errors_show(struct md_rdev *rdev, char *page)
2740 {
2741 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2742 }
2743 
2744 static ssize_t
2745 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2746 {
2747 	char *e;
2748 	unsigned long n = simple_strtoul(buf, &e, 10);
2749 	if (*buf && (*e == 0 || *e == '\n')) {
2750 		atomic_set(&rdev->corrected_errors, n);
2751 		return len;
2752 	}
2753 	return -EINVAL;
2754 }
2755 static struct rdev_sysfs_entry rdev_errors =
2756 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2757 
2758 static ssize_t
2759 slot_show(struct md_rdev *rdev, char *page)
2760 {
2761 	if (rdev->raid_disk < 0)
2762 		return sprintf(page, "none\n");
2763 	else
2764 		return sprintf(page, "%d\n", rdev->raid_disk);
2765 }
2766 
2767 static ssize_t
2768 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2769 {
2770 	char *e;
2771 	int err;
2772 	int slot = simple_strtoul(buf, &e, 10);
2773 	if (strncmp(buf, "none", 4)==0)
2774 		slot = -1;
2775 	else if (e==buf || (*e && *e!= '\n'))
2776 		return -EINVAL;
2777 	if (rdev->mddev->pers && slot == -1) {
2778 		/* Setting 'slot' on an active array requires also
2779 		 * updating the 'rd%d' link, and communicating
2780 		 * with the personality with ->hot_*_disk.
2781 		 * For now we only support removing
2782 		 * failed/spare devices.  This normally happens automatically,
2783 		 * but not when the metadata is externally managed.
2784 		 */
2785 		if (rdev->raid_disk == -1)
2786 			return -EEXIST;
2787 		/* personality does all needed checks */
2788 		if (rdev->mddev->pers->hot_remove_disk == NULL)
2789 			return -EINVAL;
2790 		err = rdev->mddev->pers->
2791 			hot_remove_disk(rdev->mddev, rdev);
2792 		if (err)
2793 			return err;
2794 		sysfs_unlink_rdev(rdev->mddev, rdev);
2795 		rdev->raid_disk = -1;
2796 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2797 		md_wakeup_thread(rdev->mddev->thread);
2798 	} else if (rdev->mddev->pers) {
2799 		/* Activating a spare .. or possibly reactivating
2800 		 * if we ever get bitmaps working here.
2801 		 */
2802 
2803 		if (rdev->raid_disk != -1)
2804 			return -EBUSY;
2805 
2806 		if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2807 			return -EBUSY;
2808 
2809 		if (rdev->mddev->pers->hot_add_disk == NULL)
2810 			return -EINVAL;
2811 
2812 		if (slot >= rdev->mddev->raid_disks &&
2813 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2814 			return -ENOSPC;
2815 
2816 		rdev->raid_disk = slot;
2817 		if (test_bit(In_sync, &rdev->flags))
2818 			rdev->saved_raid_disk = slot;
2819 		else
2820 			rdev->saved_raid_disk = -1;
2821 		clear_bit(In_sync, &rdev->flags);
2822 		err = rdev->mddev->pers->
2823 			hot_add_disk(rdev->mddev, rdev);
2824 		if (err) {
2825 			rdev->raid_disk = -1;
2826 			return err;
2827 		} else
2828 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2829 		if (sysfs_link_rdev(rdev->mddev, rdev))
2830 			/* failure here is OK */;
2831 		/* don't wakeup anyone, leave that to userspace. */
2832 	} else {
2833 		if (slot >= rdev->mddev->raid_disks &&
2834 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2835 			return -ENOSPC;
2836 		rdev->raid_disk = slot;
2837 		/* assume it is working */
2838 		clear_bit(Faulty, &rdev->flags);
2839 		clear_bit(WriteMostly, &rdev->flags);
2840 		set_bit(In_sync, &rdev->flags);
2841 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2842 	}
2843 	return len;
2844 }
2845 
2846 
2847 static struct rdev_sysfs_entry rdev_slot =
2848 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2849 
2850 static ssize_t
2851 offset_show(struct md_rdev *rdev, char *page)
2852 {
2853 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2854 }
2855 
2856 static ssize_t
2857 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2858 {
2859 	unsigned long long offset;
2860 	if (strict_strtoull(buf, 10, &offset) < 0)
2861 		return -EINVAL;
2862 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2863 		return -EBUSY;
2864 	if (rdev->sectors && rdev->mddev->external)
2865 		/* Must set offset before size, so overlap checks
2866 		 * can be sane */
2867 		return -EBUSY;
2868 	rdev->data_offset = offset;
2869 	rdev->new_data_offset = offset;
2870 	return len;
2871 }
2872 
2873 static struct rdev_sysfs_entry rdev_offset =
2874 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2875 
2876 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2877 {
2878 	return sprintf(page, "%llu\n",
2879 		       (unsigned long long)rdev->new_data_offset);
2880 }
2881 
2882 static ssize_t new_offset_store(struct md_rdev *rdev,
2883 				const char *buf, size_t len)
2884 {
2885 	unsigned long long new_offset;
2886 	struct mddev *mddev = rdev->mddev;
2887 
2888 	if (strict_strtoull(buf, 10, &new_offset) < 0)
2889 		return -EINVAL;
2890 
2891 	if (mddev->sync_thread)
2892 		return -EBUSY;
2893 	if (new_offset == rdev->data_offset)
2894 		/* reset is always permitted */
2895 		;
2896 	else if (new_offset > rdev->data_offset) {
2897 		/* must not push array size beyond rdev_sectors */
2898 		if (new_offset - rdev->data_offset
2899 		    + mddev->dev_sectors > rdev->sectors)
2900 				return -E2BIG;
2901 	}
2902 	/* Metadata worries about other space details. */
2903 
2904 	/* decreasing the offset is inconsistent with a backwards
2905 	 * reshape.
2906 	 */
2907 	if (new_offset < rdev->data_offset &&
2908 	    mddev->reshape_backwards)
2909 		return -EINVAL;
2910 	/* Increasing offset is inconsistent with forwards
2911 	 * reshape.  reshape_direction should be set to
2912 	 * 'backwards' first.
2913 	 */
2914 	if (new_offset > rdev->data_offset &&
2915 	    !mddev->reshape_backwards)
2916 		return -EINVAL;
2917 
2918 	if (mddev->pers && mddev->persistent &&
2919 	    !super_types[mddev->major_version]
2920 	    .allow_new_offset(rdev, new_offset))
2921 		return -E2BIG;
2922 	rdev->new_data_offset = new_offset;
2923 	if (new_offset > rdev->data_offset)
2924 		mddev->reshape_backwards = 1;
2925 	else if (new_offset < rdev->data_offset)
2926 		mddev->reshape_backwards = 0;
2927 
2928 	return len;
2929 }
2930 static struct rdev_sysfs_entry rdev_new_offset =
2931 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2932 
2933 static ssize_t
2934 rdev_size_show(struct md_rdev *rdev, char *page)
2935 {
2936 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2937 }
2938 
2939 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2940 {
2941 	/* check if two start/length pairs overlap */
2942 	if (s1+l1 <= s2)
2943 		return 0;
2944 	if (s2+l2 <= s1)
2945 		return 0;
2946 	return 1;
2947 }
2948 
2949 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2950 {
2951 	unsigned long long blocks;
2952 	sector_t new;
2953 
2954 	if (strict_strtoull(buf, 10, &blocks) < 0)
2955 		return -EINVAL;
2956 
2957 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2958 		return -EINVAL; /* sector conversion overflow */
2959 
2960 	new = blocks * 2;
2961 	if (new != blocks * 2)
2962 		return -EINVAL; /* unsigned long long to sector_t overflow */
2963 
2964 	*sectors = new;
2965 	return 0;
2966 }
2967 
2968 static ssize_t
2969 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2970 {
2971 	struct mddev *my_mddev = rdev->mddev;
2972 	sector_t oldsectors = rdev->sectors;
2973 	sector_t sectors;
2974 
2975 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2976 		return -EINVAL;
2977 	if (rdev->data_offset != rdev->new_data_offset)
2978 		return -EINVAL; /* too confusing */
2979 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2980 		if (my_mddev->persistent) {
2981 			sectors = super_types[my_mddev->major_version].
2982 				rdev_size_change(rdev, sectors);
2983 			if (!sectors)
2984 				return -EBUSY;
2985 		} else if (!sectors)
2986 			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2987 				rdev->data_offset;
2988 	}
2989 	if (sectors < my_mddev->dev_sectors)
2990 		return -EINVAL; /* component must fit device */
2991 
2992 	rdev->sectors = sectors;
2993 	if (sectors > oldsectors && my_mddev->external) {
2994 		/* need to check that all other rdevs with the same ->bdev
2995 		 * do not overlap.  We need to unlock the mddev to avoid
2996 		 * a deadlock.  We have already changed rdev->sectors, and if
2997 		 * we have to change it back, we will have the lock again.
2998 		 */
2999 		struct mddev *mddev;
3000 		int overlap = 0;
3001 		struct list_head *tmp;
3002 
3003 		mddev_unlock(my_mddev);
3004 		for_each_mddev(mddev, tmp) {
3005 			struct md_rdev *rdev2;
3006 
3007 			mddev_lock(mddev);
3008 			rdev_for_each(rdev2, mddev)
3009 				if (rdev->bdev == rdev2->bdev &&
3010 				    rdev != rdev2 &&
3011 				    overlaps(rdev->data_offset, rdev->sectors,
3012 					     rdev2->data_offset,
3013 					     rdev2->sectors)) {
3014 					overlap = 1;
3015 					break;
3016 				}
3017 			mddev_unlock(mddev);
3018 			if (overlap) {
3019 				mddev_put(mddev);
3020 				break;
3021 			}
3022 		}
3023 		mddev_lock(my_mddev);
3024 		if (overlap) {
3025 			/* Someone else could have slipped in a size
3026 			 * change here, but doing so is just silly.
3027 			 * We put oldsectors back because we *know* it is
3028 			 * safe, and trust userspace not to race with
3029 			 * itself
3030 			 */
3031 			rdev->sectors = oldsectors;
3032 			return -EBUSY;
3033 		}
3034 	}
3035 	return len;
3036 }
3037 
3038 static struct rdev_sysfs_entry rdev_size =
3039 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3040 
3041 
3042 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3043 {
3044 	unsigned long long recovery_start = rdev->recovery_offset;
3045 
3046 	if (test_bit(In_sync, &rdev->flags) ||
3047 	    recovery_start == MaxSector)
3048 		return sprintf(page, "none\n");
3049 
3050 	return sprintf(page, "%llu\n", recovery_start);
3051 }
3052 
3053 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3054 {
3055 	unsigned long long recovery_start;
3056 
3057 	if (cmd_match(buf, "none"))
3058 		recovery_start = MaxSector;
3059 	else if (strict_strtoull(buf, 10, &recovery_start))
3060 		return -EINVAL;
3061 
3062 	if (rdev->mddev->pers &&
3063 	    rdev->raid_disk >= 0)
3064 		return -EBUSY;
3065 
3066 	rdev->recovery_offset = recovery_start;
3067 	if (recovery_start == MaxSector)
3068 		set_bit(In_sync, &rdev->flags);
3069 	else
3070 		clear_bit(In_sync, &rdev->flags);
3071 	return len;
3072 }
3073 
3074 static struct rdev_sysfs_entry rdev_recovery_start =
3075 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3076 
3077 
3078 static ssize_t
3079 badblocks_show(struct badblocks *bb, char *page, int unack);
3080 static ssize_t
3081 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
3082 
3083 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3084 {
3085 	return badblocks_show(&rdev->badblocks, page, 0);
3086 }
3087 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3088 {
3089 	int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3090 	/* Maybe that ack was all we needed */
3091 	if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3092 		wake_up(&rdev->blocked_wait);
3093 	return rv;
3094 }
3095 static struct rdev_sysfs_entry rdev_bad_blocks =
3096 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3097 
3098 
3099 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3100 {
3101 	return badblocks_show(&rdev->badblocks, page, 1);
3102 }
3103 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3104 {
3105 	return badblocks_store(&rdev->badblocks, page, len, 1);
3106 }
3107 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3108 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3109 
3110 static struct attribute *rdev_default_attrs[] = {
3111 	&rdev_state.attr,
3112 	&rdev_errors.attr,
3113 	&rdev_slot.attr,
3114 	&rdev_offset.attr,
3115 	&rdev_new_offset.attr,
3116 	&rdev_size.attr,
3117 	&rdev_recovery_start.attr,
3118 	&rdev_bad_blocks.attr,
3119 	&rdev_unack_bad_blocks.attr,
3120 	NULL,
3121 };
3122 static ssize_t
3123 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3124 {
3125 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3126 	struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3127 	struct mddev *mddev = rdev->mddev;
3128 	ssize_t rv;
3129 
3130 	if (!entry->show)
3131 		return -EIO;
3132 
3133 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
3134 	if (!rv) {
3135 		if (rdev->mddev == NULL)
3136 			rv = -EBUSY;
3137 		else
3138 			rv = entry->show(rdev, page);
3139 		mddev_unlock(mddev);
3140 	}
3141 	return rv;
3142 }
3143 
3144 static ssize_t
3145 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3146 	      const char *page, size_t length)
3147 {
3148 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3149 	struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3150 	ssize_t rv;
3151 	struct mddev *mddev = rdev->mddev;
3152 
3153 	if (!entry->store)
3154 		return -EIO;
3155 	if (!capable(CAP_SYS_ADMIN))
3156 		return -EACCES;
3157 	rv = mddev ? mddev_lock(mddev): -EBUSY;
3158 	if (!rv) {
3159 		if (rdev->mddev == NULL)
3160 			rv = -EBUSY;
3161 		else
3162 			rv = entry->store(rdev, page, length);
3163 		mddev_unlock(mddev);
3164 	}
3165 	return rv;
3166 }
3167 
3168 static void rdev_free(struct kobject *ko)
3169 {
3170 	struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3171 	kfree(rdev);
3172 }
3173 static const struct sysfs_ops rdev_sysfs_ops = {
3174 	.show		= rdev_attr_show,
3175 	.store		= rdev_attr_store,
3176 };
3177 static struct kobj_type rdev_ktype = {
3178 	.release	= rdev_free,
3179 	.sysfs_ops	= &rdev_sysfs_ops,
3180 	.default_attrs	= rdev_default_attrs,
3181 };
3182 
3183 int md_rdev_init(struct md_rdev *rdev)
3184 {
3185 	rdev->desc_nr = -1;
3186 	rdev->saved_raid_disk = -1;
3187 	rdev->raid_disk = -1;
3188 	rdev->flags = 0;
3189 	rdev->data_offset = 0;
3190 	rdev->new_data_offset = 0;
3191 	rdev->sb_events = 0;
3192 	rdev->last_read_error.tv_sec  = 0;
3193 	rdev->last_read_error.tv_nsec = 0;
3194 	rdev->sb_loaded = 0;
3195 	rdev->bb_page = NULL;
3196 	atomic_set(&rdev->nr_pending, 0);
3197 	atomic_set(&rdev->read_errors, 0);
3198 	atomic_set(&rdev->corrected_errors, 0);
3199 
3200 	INIT_LIST_HEAD(&rdev->same_set);
3201 	init_waitqueue_head(&rdev->blocked_wait);
3202 
3203 	/* Add space to store bad block list.
3204 	 * This reserves the space even on arrays where it cannot
3205 	 * be used - I wonder if that matters
3206 	 */
3207 	rdev->badblocks.count = 0;
3208 	rdev->badblocks.shift = 0;
3209 	rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3210 	seqlock_init(&rdev->badblocks.lock);
3211 	if (rdev->badblocks.page == NULL)
3212 		return -ENOMEM;
3213 
3214 	return 0;
3215 }
3216 EXPORT_SYMBOL_GPL(md_rdev_init);
3217 /*
3218  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3219  *
3220  * mark the device faulty if:
3221  *
3222  *   - the device is nonexistent (zero size)
3223  *   - the device has no valid superblock
3224  *
3225  * a faulty rdev _never_ has rdev->sb set.
3226  */
3227 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3228 {
3229 	char b[BDEVNAME_SIZE];
3230 	int err;
3231 	struct md_rdev *rdev;
3232 	sector_t size;
3233 
3234 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3235 	if (!rdev) {
3236 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
3237 		return ERR_PTR(-ENOMEM);
3238 	}
3239 
3240 	err = md_rdev_init(rdev);
3241 	if (err)
3242 		goto abort_free;
3243 	err = alloc_disk_sb(rdev);
3244 	if (err)
3245 		goto abort_free;
3246 
3247 	err = lock_rdev(rdev, newdev, super_format == -2);
3248 	if (err)
3249 		goto abort_free;
3250 
3251 	kobject_init(&rdev->kobj, &rdev_ktype);
3252 
3253 	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3254 	if (!size) {
3255 		printk(KERN_WARNING
3256 			"md: %s has zero or unknown size, marking faulty!\n",
3257 			bdevname(rdev->bdev,b));
3258 		err = -EINVAL;
3259 		goto abort_free;
3260 	}
3261 
3262 	if (super_format >= 0) {
3263 		err = super_types[super_format].
3264 			load_super(rdev, NULL, super_minor);
3265 		if (err == -EINVAL) {
3266 			printk(KERN_WARNING
3267 				"md: %s does not have a valid v%d.%d "
3268 			       "superblock, not importing!\n",
3269 				bdevname(rdev->bdev,b),
3270 			       super_format, super_minor);
3271 			goto abort_free;
3272 		}
3273 		if (err < 0) {
3274 			printk(KERN_WARNING
3275 				"md: could not read %s's sb, not importing!\n",
3276 				bdevname(rdev->bdev,b));
3277 			goto abort_free;
3278 		}
3279 	}
3280 	if (super_format == -1)
3281 		/* hot-add for 0.90, or non-persistent: so no badblocks */
3282 		rdev->badblocks.shift = -1;
3283 
3284 	return rdev;
3285 
3286 abort_free:
3287 	if (rdev->bdev)
3288 		unlock_rdev(rdev);
3289 	md_rdev_clear(rdev);
3290 	kfree(rdev);
3291 	return ERR_PTR(err);
3292 }
3293 
3294 /*
3295  * Check a full RAID array for plausibility
3296  */
3297 
3298 
3299 static void analyze_sbs(struct mddev * mddev)
3300 {
3301 	int i;
3302 	struct md_rdev *rdev, *freshest, *tmp;
3303 	char b[BDEVNAME_SIZE];
3304 
3305 	freshest = NULL;
3306 	rdev_for_each_safe(rdev, tmp, mddev)
3307 		switch (super_types[mddev->major_version].
3308 			load_super(rdev, freshest, mddev->minor_version)) {
3309 		case 1:
3310 			freshest = rdev;
3311 			break;
3312 		case 0:
3313 			break;
3314 		default:
3315 			printk( KERN_ERR \
3316 				"md: fatal superblock inconsistency in %s"
3317 				" -- removing from array\n",
3318 				bdevname(rdev->bdev,b));
3319 			kick_rdev_from_array(rdev);
3320 		}
3321 
3322 
3323 	super_types[mddev->major_version].
3324 		validate_super(mddev, freshest);
3325 
3326 	i = 0;
3327 	rdev_for_each_safe(rdev, tmp, mddev) {
3328 		if (mddev->max_disks &&
3329 		    (rdev->desc_nr >= mddev->max_disks ||
3330 		     i > mddev->max_disks)) {
3331 			printk(KERN_WARNING
3332 			       "md: %s: %s: only %d devices permitted\n",
3333 			       mdname(mddev), bdevname(rdev->bdev, b),
3334 			       mddev->max_disks);
3335 			kick_rdev_from_array(rdev);
3336 			continue;
3337 		}
3338 		if (rdev != freshest)
3339 			if (super_types[mddev->major_version].
3340 			    validate_super(mddev, rdev)) {
3341 				printk(KERN_WARNING "md: kicking non-fresh %s"
3342 					" from array!\n",
3343 					bdevname(rdev->bdev,b));
3344 				kick_rdev_from_array(rdev);
3345 				continue;
3346 			}
3347 		if (mddev->level == LEVEL_MULTIPATH) {
3348 			rdev->desc_nr = i++;
3349 			rdev->raid_disk = rdev->desc_nr;
3350 			set_bit(In_sync, &rdev->flags);
3351 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3352 			rdev->raid_disk = -1;
3353 			clear_bit(In_sync, &rdev->flags);
3354 		}
3355 	}
3356 }
3357 
3358 /* Read a fixed-point number.
3359  * Numbers in sysfs attributes should be in "standard" units where
3360  * possible, so time should be in seconds.
3361  * However we internally use a a much smaller unit such as
3362  * milliseconds or jiffies.
3363  * This function takes a decimal number with a possible fractional
3364  * component, and produces an integer which is the result of
3365  * multiplying that number by 10^'scale'.
3366  * all without any floating-point arithmetic.
3367  */
3368 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3369 {
3370 	unsigned long result = 0;
3371 	long decimals = -1;
3372 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3373 		if (*cp == '.')
3374 			decimals = 0;
3375 		else if (decimals < scale) {
3376 			unsigned int value;
3377 			value = *cp - '0';
3378 			result = result * 10 + value;
3379 			if (decimals >= 0)
3380 				decimals++;
3381 		}
3382 		cp++;
3383 	}
3384 	if (*cp == '\n')
3385 		cp++;
3386 	if (*cp)
3387 		return -EINVAL;
3388 	if (decimals < 0)
3389 		decimals = 0;
3390 	while (decimals < scale) {
3391 		result *= 10;
3392 		decimals ++;
3393 	}
3394 	*res = result;
3395 	return 0;
3396 }
3397 
3398 
3399 static void md_safemode_timeout(unsigned long data);
3400 
3401 static ssize_t
3402 safe_delay_show(struct mddev *mddev, char *page)
3403 {
3404 	int msec = (mddev->safemode_delay*1000)/HZ;
3405 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3406 }
3407 static ssize_t
3408 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3409 {
3410 	unsigned long msec;
3411 
3412 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3413 		return -EINVAL;
3414 	if (msec == 0)
3415 		mddev->safemode_delay = 0;
3416 	else {
3417 		unsigned long old_delay = mddev->safemode_delay;
3418 		mddev->safemode_delay = (msec*HZ)/1000;
3419 		if (mddev->safemode_delay == 0)
3420 			mddev->safemode_delay = 1;
3421 		if (mddev->safemode_delay < old_delay)
3422 			md_safemode_timeout((unsigned long)mddev);
3423 	}
3424 	return len;
3425 }
3426 static struct md_sysfs_entry md_safe_delay =
3427 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3428 
3429 static ssize_t
3430 level_show(struct mddev *mddev, char *page)
3431 {
3432 	struct md_personality *p = mddev->pers;
3433 	if (p)
3434 		return sprintf(page, "%s\n", p->name);
3435 	else if (mddev->clevel[0])
3436 		return sprintf(page, "%s\n", mddev->clevel);
3437 	else if (mddev->level != LEVEL_NONE)
3438 		return sprintf(page, "%d\n", mddev->level);
3439 	else
3440 		return 0;
3441 }
3442 
3443 static ssize_t
3444 level_store(struct mddev *mddev, const char *buf, size_t len)
3445 {
3446 	char clevel[16];
3447 	ssize_t rv = len;
3448 	struct md_personality *pers;
3449 	long level;
3450 	void *priv;
3451 	struct md_rdev *rdev;
3452 
3453 	if (mddev->pers == NULL) {
3454 		if (len == 0)
3455 			return 0;
3456 		if (len >= sizeof(mddev->clevel))
3457 			return -ENOSPC;
3458 		strncpy(mddev->clevel, buf, len);
3459 		if (mddev->clevel[len-1] == '\n')
3460 			len--;
3461 		mddev->clevel[len] = 0;
3462 		mddev->level = LEVEL_NONE;
3463 		return rv;
3464 	}
3465 
3466 	/* request to change the personality.  Need to ensure:
3467 	 *  - array is not engaged in resync/recovery/reshape
3468 	 *  - old personality can be suspended
3469 	 *  - new personality will access other array.
3470 	 */
3471 
3472 	if (mddev->sync_thread ||
3473 	    mddev->reshape_position != MaxSector ||
3474 	    mddev->sysfs_active)
3475 		return -EBUSY;
3476 
3477 	if (!mddev->pers->quiesce) {
3478 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3479 		       mdname(mddev), mddev->pers->name);
3480 		return -EINVAL;
3481 	}
3482 
3483 	/* Now find the new personality */
3484 	if (len == 0 || len >= sizeof(clevel))
3485 		return -EINVAL;
3486 	strncpy(clevel, buf, len);
3487 	if (clevel[len-1] == '\n')
3488 		len--;
3489 	clevel[len] = 0;
3490 	if (strict_strtol(clevel, 10, &level))
3491 		level = LEVEL_NONE;
3492 
3493 	if (request_module("md-%s", clevel) != 0)
3494 		request_module("md-level-%s", clevel);
3495 	spin_lock(&pers_lock);
3496 	pers = find_pers(level, clevel);
3497 	if (!pers || !try_module_get(pers->owner)) {
3498 		spin_unlock(&pers_lock);
3499 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3500 		return -EINVAL;
3501 	}
3502 	spin_unlock(&pers_lock);
3503 
3504 	if (pers == mddev->pers) {
3505 		/* Nothing to do! */
3506 		module_put(pers->owner);
3507 		return rv;
3508 	}
3509 	if (!pers->takeover) {
3510 		module_put(pers->owner);
3511 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3512 		       mdname(mddev), clevel);
3513 		return -EINVAL;
3514 	}
3515 
3516 	rdev_for_each(rdev, mddev)
3517 		rdev->new_raid_disk = rdev->raid_disk;
3518 
3519 	/* ->takeover must set new_* and/or delta_disks
3520 	 * if it succeeds, and may set them when it fails.
3521 	 */
3522 	priv = pers->takeover(mddev);
3523 	if (IS_ERR(priv)) {
3524 		mddev->new_level = mddev->level;
3525 		mddev->new_layout = mddev->layout;
3526 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3527 		mddev->raid_disks -= mddev->delta_disks;
3528 		mddev->delta_disks = 0;
3529 		mddev->reshape_backwards = 0;
3530 		module_put(pers->owner);
3531 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3532 		       mdname(mddev), clevel);
3533 		return PTR_ERR(priv);
3534 	}
3535 
3536 	/* Looks like we have a winner */
3537 	mddev_suspend(mddev);
3538 	mddev->pers->stop(mddev);
3539 
3540 	if (mddev->pers->sync_request == NULL &&
3541 	    pers->sync_request != NULL) {
3542 		/* need to add the md_redundancy_group */
3543 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3544 			printk(KERN_WARNING
3545 			       "md: cannot register extra attributes for %s\n",
3546 			       mdname(mddev));
3547 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3548 	}
3549 	if (mddev->pers->sync_request != NULL &&
3550 	    pers->sync_request == NULL) {
3551 		/* need to remove the md_redundancy_group */
3552 		if (mddev->to_remove == NULL)
3553 			mddev->to_remove = &md_redundancy_group;
3554 	}
3555 
3556 	if (mddev->pers->sync_request == NULL &&
3557 	    mddev->external) {
3558 		/* We are converting from a no-redundancy array
3559 		 * to a redundancy array and metadata is managed
3560 		 * externally so we need to be sure that writes
3561 		 * won't block due to a need to transition
3562 		 *      clean->dirty
3563 		 * until external management is started.
3564 		 */
3565 		mddev->in_sync = 0;
3566 		mddev->safemode_delay = 0;
3567 		mddev->safemode = 0;
3568 	}
3569 
3570 	rdev_for_each(rdev, mddev) {
3571 		if (rdev->raid_disk < 0)
3572 			continue;
3573 		if (rdev->new_raid_disk >= mddev->raid_disks)
3574 			rdev->new_raid_disk = -1;
3575 		if (rdev->new_raid_disk == rdev->raid_disk)
3576 			continue;
3577 		sysfs_unlink_rdev(mddev, rdev);
3578 	}
3579 	rdev_for_each(rdev, mddev) {
3580 		if (rdev->raid_disk < 0)
3581 			continue;
3582 		if (rdev->new_raid_disk == rdev->raid_disk)
3583 			continue;
3584 		rdev->raid_disk = rdev->new_raid_disk;
3585 		if (rdev->raid_disk < 0)
3586 			clear_bit(In_sync, &rdev->flags);
3587 		else {
3588 			if (sysfs_link_rdev(mddev, rdev))
3589 				printk(KERN_WARNING "md: cannot register rd%d"
3590 				       " for %s after level change\n",
3591 				       rdev->raid_disk, mdname(mddev));
3592 		}
3593 	}
3594 
3595 	module_put(mddev->pers->owner);
3596 	mddev->pers = pers;
3597 	mddev->private = priv;
3598 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3599 	mddev->level = mddev->new_level;
3600 	mddev->layout = mddev->new_layout;
3601 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3602 	mddev->delta_disks = 0;
3603 	mddev->reshape_backwards = 0;
3604 	mddev->degraded = 0;
3605 	if (mddev->pers->sync_request == NULL) {
3606 		/* this is now an array without redundancy, so
3607 		 * it must always be in_sync
3608 		 */
3609 		mddev->in_sync = 1;
3610 		del_timer_sync(&mddev->safemode_timer);
3611 	}
3612 	pers->run(mddev);
3613 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3614 	mddev_resume(mddev);
3615 	sysfs_notify(&mddev->kobj, NULL, "level");
3616 	md_new_event(mddev);
3617 	return rv;
3618 }
3619 
3620 static struct md_sysfs_entry md_level =
3621 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3622 
3623 
3624 static ssize_t
3625 layout_show(struct mddev *mddev, char *page)
3626 {
3627 	/* just a number, not meaningful for all levels */
3628 	if (mddev->reshape_position != MaxSector &&
3629 	    mddev->layout != mddev->new_layout)
3630 		return sprintf(page, "%d (%d)\n",
3631 			       mddev->new_layout, mddev->layout);
3632 	return sprintf(page, "%d\n", mddev->layout);
3633 }
3634 
3635 static ssize_t
3636 layout_store(struct mddev *mddev, const char *buf, size_t len)
3637 {
3638 	char *e;
3639 	unsigned long n = simple_strtoul(buf, &e, 10);
3640 
3641 	if (!*buf || (*e && *e != '\n'))
3642 		return -EINVAL;
3643 
3644 	if (mddev->pers) {
3645 		int err;
3646 		if (mddev->pers->check_reshape == NULL)
3647 			return -EBUSY;
3648 		mddev->new_layout = n;
3649 		err = mddev->pers->check_reshape(mddev);
3650 		if (err) {
3651 			mddev->new_layout = mddev->layout;
3652 			return err;
3653 		}
3654 	} else {
3655 		mddev->new_layout = n;
3656 		if (mddev->reshape_position == MaxSector)
3657 			mddev->layout = n;
3658 	}
3659 	return len;
3660 }
3661 static struct md_sysfs_entry md_layout =
3662 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3663 
3664 
3665 static ssize_t
3666 raid_disks_show(struct mddev *mddev, char *page)
3667 {
3668 	if (mddev->raid_disks == 0)
3669 		return 0;
3670 	if (mddev->reshape_position != MaxSector &&
3671 	    mddev->delta_disks != 0)
3672 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3673 			       mddev->raid_disks - mddev->delta_disks);
3674 	return sprintf(page, "%d\n", mddev->raid_disks);
3675 }
3676 
3677 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3678 
3679 static ssize_t
3680 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3681 {
3682 	char *e;
3683 	int rv = 0;
3684 	unsigned long n = simple_strtoul(buf, &e, 10);
3685 
3686 	if (!*buf || (*e && *e != '\n'))
3687 		return -EINVAL;
3688 
3689 	if (mddev->pers)
3690 		rv = update_raid_disks(mddev, n);
3691 	else if (mddev->reshape_position != MaxSector) {
3692 		struct md_rdev *rdev;
3693 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3694 
3695 		rdev_for_each(rdev, mddev) {
3696 			if (olddisks < n &&
3697 			    rdev->data_offset < rdev->new_data_offset)
3698 				return -EINVAL;
3699 			if (olddisks > n &&
3700 			    rdev->data_offset > rdev->new_data_offset)
3701 				return -EINVAL;
3702 		}
3703 		mddev->delta_disks = n - olddisks;
3704 		mddev->raid_disks = n;
3705 		mddev->reshape_backwards = (mddev->delta_disks < 0);
3706 	} else
3707 		mddev->raid_disks = n;
3708 	return rv ? rv : len;
3709 }
3710 static struct md_sysfs_entry md_raid_disks =
3711 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3712 
3713 static ssize_t
3714 chunk_size_show(struct mddev *mddev, char *page)
3715 {
3716 	if (mddev->reshape_position != MaxSector &&
3717 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3718 		return sprintf(page, "%d (%d)\n",
3719 			       mddev->new_chunk_sectors << 9,
3720 			       mddev->chunk_sectors << 9);
3721 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3722 }
3723 
3724 static ssize_t
3725 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3726 {
3727 	char *e;
3728 	unsigned long n = simple_strtoul(buf, &e, 10);
3729 
3730 	if (!*buf || (*e && *e != '\n'))
3731 		return -EINVAL;
3732 
3733 	if (mddev->pers) {
3734 		int err;
3735 		if (mddev->pers->check_reshape == NULL)
3736 			return -EBUSY;
3737 		mddev->new_chunk_sectors = n >> 9;
3738 		err = mddev->pers->check_reshape(mddev);
3739 		if (err) {
3740 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3741 			return err;
3742 		}
3743 	} else {
3744 		mddev->new_chunk_sectors = n >> 9;
3745 		if (mddev->reshape_position == MaxSector)
3746 			mddev->chunk_sectors = n >> 9;
3747 	}
3748 	return len;
3749 }
3750 static struct md_sysfs_entry md_chunk_size =
3751 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3752 
3753 static ssize_t
3754 resync_start_show(struct mddev *mddev, char *page)
3755 {
3756 	if (mddev->recovery_cp == MaxSector)
3757 		return sprintf(page, "none\n");
3758 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3759 }
3760 
3761 static ssize_t
3762 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3763 {
3764 	char *e;
3765 	unsigned long long n = simple_strtoull(buf, &e, 10);
3766 
3767 	if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3768 		return -EBUSY;
3769 	if (cmd_match(buf, "none"))
3770 		n = MaxSector;
3771 	else if (!*buf || (*e && *e != '\n'))
3772 		return -EINVAL;
3773 
3774 	mddev->recovery_cp = n;
3775 	return len;
3776 }
3777 static struct md_sysfs_entry md_resync_start =
3778 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3779 
3780 /*
3781  * The array state can be:
3782  *
3783  * clear
3784  *     No devices, no size, no level
3785  *     Equivalent to STOP_ARRAY ioctl
3786  * inactive
3787  *     May have some settings, but array is not active
3788  *        all IO results in error
3789  *     When written, doesn't tear down array, but just stops it
3790  * suspended (not supported yet)
3791  *     All IO requests will block. The array can be reconfigured.
3792  *     Writing this, if accepted, will block until array is quiescent
3793  * readonly
3794  *     no resync can happen.  no superblocks get written.
3795  *     write requests fail
3796  * read-auto
3797  *     like readonly, but behaves like 'clean' on a write request.
3798  *
3799  * clean - no pending writes, but otherwise active.
3800  *     When written to inactive array, starts without resync
3801  *     If a write request arrives then
3802  *       if metadata is known, mark 'dirty' and switch to 'active'.
3803  *       if not known, block and switch to write-pending
3804  *     If written to an active array that has pending writes, then fails.
3805  * active
3806  *     fully active: IO and resync can be happening.
3807  *     When written to inactive array, starts with resync
3808  *
3809  * write-pending
3810  *     clean, but writes are blocked waiting for 'active' to be written.
3811  *
3812  * active-idle
3813  *     like active, but no writes have been seen for a while (100msec).
3814  *
3815  */
3816 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3817 		   write_pending, active_idle, bad_word};
3818 static char *array_states[] = {
3819 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3820 	"write-pending", "active-idle", NULL };
3821 
3822 static int match_word(const char *word, char **list)
3823 {
3824 	int n;
3825 	for (n=0; list[n]; n++)
3826 		if (cmd_match(word, list[n]))
3827 			break;
3828 	return n;
3829 }
3830 
3831 static ssize_t
3832 array_state_show(struct mddev *mddev, char *page)
3833 {
3834 	enum array_state st = inactive;
3835 
3836 	if (mddev->pers)
3837 		switch(mddev->ro) {
3838 		case 1:
3839 			st = readonly;
3840 			break;
3841 		case 2:
3842 			st = read_auto;
3843 			break;
3844 		case 0:
3845 			if (mddev->in_sync)
3846 				st = clean;
3847 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3848 				st = write_pending;
3849 			else if (mddev->safemode)
3850 				st = active_idle;
3851 			else
3852 				st = active;
3853 		}
3854 	else {
3855 		if (list_empty(&mddev->disks) &&
3856 		    mddev->raid_disks == 0 &&
3857 		    mddev->dev_sectors == 0)
3858 			st = clear;
3859 		else
3860 			st = inactive;
3861 	}
3862 	return sprintf(page, "%s\n", array_states[st]);
3863 }
3864 
3865 static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
3866 static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
3867 static int do_md_run(struct mddev * mddev);
3868 static int restart_array(struct mddev *mddev);
3869 
3870 static ssize_t
3871 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3872 {
3873 	int err = -EINVAL;
3874 	enum array_state st = match_word(buf, array_states);
3875 	switch(st) {
3876 	case bad_word:
3877 		break;
3878 	case clear:
3879 		/* stopping an active array */
3880 		err = do_md_stop(mddev, 0, NULL);
3881 		break;
3882 	case inactive:
3883 		/* stopping an active array */
3884 		if (mddev->pers)
3885 			err = do_md_stop(mddev, 2, NULL);
3886 		else
3887 			err = 0; /* already inactive */
3888 		break;
3889 	case suspended:
3890 		break; /* not supported yet */
3891 	case readonly:
3892 		if (mddev->pers)
3893 			err = md_set_readonly(mddev, NULL);
3894 		else {
3895 			mddev->ro = 1;
3896 			set_disk_ro(mddev->gendisk, 1);
3897 			err = do_md_run(mddev);
3898 		}
3899 		break;
3900 	case read_auto:
3901 		if (mddev->pers) {
3902 			if (mddev->ro == 0)
3903 				err = md_set_readonly(mddev, NULL);
3904 			else if (mddev->ro == 1)
3905 				err = restart_array(mddev);
3906 			if (err == 0) {
3907 				mddev->ro = 2;
3908 				set_disk_ro(mddev->gendisk, 0);
3909 			}
3910 		} else {
3911 			mddev->ro = 2;
3912 			err = do_md_run(mddev);
3913 		}
3914 		break;
3915 	case clean:
3916 		if (mddev->pers) {
3917 			restart_array(mddev);
3918 			spin_lock_irq(&mddev->write_lock);
3919 			if (atomic_read(&mddev->writes_pending) == 0) {
3920 				if (mddev->in_sync == 0) {
3921 					mddev->in_sync = 1;
3922 					if (mddev->safemode == 1)
3923 						mddev->safemode = 0;
3924 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3925 				}
3926 				err = 0;
3927 			} else
3928 				err = -EBUSY;
3929 			spin_unlock_irq(&mddev->write_lock);
3930 		} else
3931 			err = -EINVAL;
3932 		break;
3933 	case active:
3934 		if (mddev->pers) {
3935 			restart_array(mddev);
3936 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3937 			wake_up(&mddev->sb_wait);
3938 			err = 0;
3939 		} else {
3940 			mddev->ro = 0;
3941 			set_disk_ro(mddev->gendisk, 0);
3942 			err = do_md_run(mddev);
3943 		}
3944 		break;
3945 	case write_pending:
3946 	case active_idle:
3947 		/* these cannot be set */
3948 		break;
3949 	}
3950 	if (err)
3951 		return err;
3952 	else {
3953 		if (mddev->hold_active == UNTIL_IOCTL)
3954 			mddev->hold_active = 0;
3955 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3956 		return len;
3957 	}
3958 }
3959 static struct md_sysfs_entry md_array_state =
3960 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3961 
3962 static ssize_t
3963 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
3964 	return sprintf(page, "%d\n",
3965 		       atomic_read(&mddev->max_corr_read_errors));
3966 }
3967 
3968 static ssize_t
3969 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
3970 {
3971 	char *e;
3972 	unsigned long n = simple_strtoul(buf, &e, 10);
3973 
3974 	if (*buf && (*e == 0 || *e == '\n')) {
3975 		atomic_set(&mddev->max_corr_read_errors, n);
3976 		return len;
3977 	}
3978 	return -EINVAL;
3979 }
3980 
3981 static struct md_sysfs_entry max_corr_read_errors =
3982 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3983 	max_corrected_read_errors_store);
3984 
3985 static ssize_t
3986 null_show(struct mddev *mddev, char *page)
3987 {
3988 	return -EINVAL;
3989 }
3990 
3991 static ssize_t
3992 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
3993 {
3994 	/* buf must be %d:%d\n? giving major and minor numbers */
3995 	/* The new device is added to the array.
3996 	 * If the array has a persistent superblock, we read the
3997 	 * superblock to initialise info and check validity.
3998 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3999 	 * which mainly checks size.
4000 	 */
4001 	char *e;
4002 	int major = simple_strtoul(buf, &e, 10);
4003 	int minor;
4004 	dev_t dev;
4005 	struct md_rdev *rdev;
4006 	int err;
4007 
4008 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4009 		return -EINVAL;
4010 	minor = simple_strtoul(e+1, &e, 10);
4011 	if (*e && *e != '\n')
4012 		return -EINVAL;
4013 	dev = MKDEV(major, minor);
4014 	if (major != MAJOR(dev) ||
4015 	    minor != MINOR(dev))
4016 		return -EOVERFLOW;
4017 
4018 
4019 	if (mddev->persistent) {
4020 		rdev = md_import_device(dev, mddev->major_version,
4021 					mddev->minor_version);
4022 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4023 			struct md_rdev *rdev0
4024 				= list_entry(mddev->disks.next,
4025 					     struct md_rdev, same_set);
4026 			err = super_types[mddev->major_version]
4027 				.load_super(rdev, rdev0, mddev->minor_version);
4028 			if (err < 0)
4029 				goto out;
4030 		}
4031 	} else if (mddev->external)
4032 		rdev = md_import_device(dev, -2, -1);
4033 	else
4034 		rdev = md_import_device(dev, -1, -1);
4035 
4036 	if (IS_ERR(rdev))
4037 		return PTR_ERR(rdev);
4038 	err = bind_rdev_to_array(rdev, mddev);
4039  out:
4040 	if (err)
4041 		export_rdev(rdev);
4042 	return err ? err : len;
4043 }
4044 
4045 static struct md_sysfs_entry md_new_device =
4046 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4047 
4048 static ssize_t
4049 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4050 {
4051 	char *end;
4052 	unsigned long chunk, end_chunk;
4053 
4054 	if (!mddev->bitmap)
4055 		goto out;
4056 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4057 	while (*buf) {
4058 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
4059 		if (buf == end) break;
4060 		if (*end == '-') { /* range */
4061 			buf = end + 1;
4062 			end_chunk = simple_strtoul(buf, &end, 0);
4063 			if (buf == end) break;
4064 		}
4065 		if (*end && !isspace(*end)) break;
4066 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4067 		buf = skip_spaces(end);
4068 	}
4069 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4070 out:
4071 	return len;
4072 }
4073 
4074 static struct md_sysfs_entry md_bitmap =
4075 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4076 
4077 static ssize_t
4078 size_show(struct mddev *mddev, char *page)
4079 {
4080 	return sprintf(page, "%llu\n",
4081 		(unsigned long long)mddev->dev_sectors / 2);
4082 }
4083 
4084 static int update_size(struct mddev *mddev, sector_t num_sectors);
4085 
4086 static ssize_t
4087 size_store(struct mddev *mddev, const char *buf, size_t len)
4088 {
4089 	/* If array is inactive, we can reduce the component size, but
4090 	 * not increase it (except from 0).
4091 	 * If array is active, we can try an on-line resize
4092 	 */
4093 	sector_t sectors;
4094 	int err = strict_blocks_to_sectors(buf, &sectors);
4095 
4096 	if (err < 0)
4097 		return err;
4098 	if (mddev->pers) {
4099 		err = update_size(mddev, sectors);
4100 		md_update_sb(mddev, 1);
4101 	} else {
4102 		if (mddev->dev_sectors == 0 ||
4103 		    mddev->dev_sectors > sectors)
4104 			mddev->dev_sectors = sectors;
4105 		else
4106 			err = -ENOSPC;
4107 	}
4108 	return err ? err : len;
4109 }
4110 
4111 static struct md_sysfs_entry md_size =
4112 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4113 
4114 
4115 /* Metdata version.
4116  * This is one of
4117  *   'none' for arrays with no metadata (good luck...)
4118  *   'external' for arrays with externally managed metadata,
4119  * or N.M for internally known formats
4120  */
4121 static ssize_t
4122 metadata_show(struct mddev *mddev, char *page)
4123 {
4124 	if (mddev->persistent)
4125 		return sprintf(page, "%d.%d\n",
4126 			       mddev->major_version, mddev->minor_version);
4127 	else if (mddev->external)
4128 		return sprintf(page, "external:%s\n", mddev->metadata_type);
4129 	else
4130 		return sprintf(page, "none\n");
4131 }
4132 
4133 static ssize_t
4134 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4135 {
4136 	int major, minor;
4137 	char *e;
4138 	/* Changing the details of 'external' metadata is
4139 	 * always permitted.  Otherwise there must be
4140 	 * no devices attached to the array.
4141 	 */
4142 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
4143 		;
4144 	else if (!list_empty(&mddev->disks))
4145 		return -EBUSY;
4146 
4147 	if (cmd_match(buf, "none")) {
4148 		mddev->persistent = 0;
4149 		mddev->external = 0;
4150 		mddev->major_version = 0;
4151 		mddev->minor_version = 90;
4152 		return len;
4153 	}
4154 	if (strncmp(buf, "external:", 9) == 0) {
4155 		size_t namelen = len-9;
4156 		if (namelen >= sizeof(mddev->metadata_type))
4157 			namelen = sizeof(mddev->metadata_type)-1;
4158 		strncpy(mddev->metadata_type, buf+9, namelen);
4159 		mddev->metadata_type[namelen] = 0;
4160 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
4161 			mddev->metadata_type[--namelen] = 0;
4162 		mddev->persistent = 0;
4163 		mddev->external = 1;
4164 		mddev->major_version = 0;
4165 		mddev->minor_version = 90;
4166 		return len;
4167 	}
4168 	major = simple_strtoul(buf, &e, 10);
4169 	if (e==buf || *e != '.')
4170 		return -EINVAL;
4171 	buf = e+1;
4172 	minor = simple_strtoul(buf, &e, 10);
4173 	if (e==buf || (*e && *e != '\n') )
4174 		return -EINVAL;
4175 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4176 		return -ENOENT;
4177 	mddev->major_version = major;
4178 	mddev->minor_version = minor;
4179 	mddev->persistent = 1;
4180 	mddev->external = 0;
4181 	return len;
4182 }
4183 
4184 static struct md_sysfs_entry md_metadata =
4185 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4186 
4187 static ssize_t
4188 action_show(struct mddev *mddev, char *page)
4189 {
4190 	char *type = "idle";
4191 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4192 		type = "frozen";
4193 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4194 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4195 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4196 			type = "reshape";
4197 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4198 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4199 				type = "resync";
4200 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4201 				type = "check";
4202 			else
4203 				type = "repair";
4204 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4205 			type = "recover";
4206 	}
4207 	return sprintf(page, "%s\n", type);
4208 }
4209 
4210 static void reap_sync_thread(struct mddev *mddev);
4211 
4212 static ssize_t
4213 action_store(struct mddev *mddev, const char *page, size_t len)
4214 {
4215 	if (!mddev->pers || !mddev->pers->sync_request)
4216 		return -EINVAL;
4217 
4218 	if (cmd_match(page, "frozen"))
4219 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4220 	else
4221 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4222 
4223 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4224 		if (mddev->sync_thread) {
4225 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4226 			reap_sync_thread(mddev);
4227 		}
4228 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4229 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4230 		return -EBUSY;
4231 	else if (cmd_match(page, "resync"))
4232 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4233 	else if (cmd_match(page, "recover")) {
4234 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4235 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4236 	} else if (cmd_match(page, "reshape")) {
4237 		int err;
4238 		if (mddev->pers->start_reshape == NULL)
4239 			return -EINVAL;
4240 		err = mddev->pers->start_reshape(mddev);
4241 		if (err)
4242 			return err;
4243 		sysfs_notify(&mddev->kobj, NULL, "degraded");
4244 	} else {
4245 		if (cmd_match(page, "check"))
4246 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4247 		else if (!cmd_match(page, "repair"))
4248 			return -EINVAL;
4249 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4250 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4251 	}
4252 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4253 	md_wakeup_thread(mddev->thread);
4254 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4255 	return len;
4256 }
4257 
4258 static ssize_t
4259 mismatch_cnt_show(struct mddev *mddev, char *page)
4260 {
4261 	return sprintf(page, "%llu\n",
4262 		       (unsigned long long) mddev->resync_mismatches);
4263 }
4264 
4265 static struct md_sysfs_entry md_scan_mode =
4266 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4267 
4268 
4269 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4270 
4271 static ssize_t
4272 sync_min_show(struct mddev *mddev, char *page)
4273 {
4274 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
4275 		       mddev->sync_speed_min ? "local": "system");
4276 }
4277 
4278 static ssize_t
4279 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4280 {
4281 	int min;
4282 	char *e;
4283 	if (strncmp(buf, "system", 6)==0) {
4284 		mddev->sync_speed_min = 0;
4285 		return len;
4286 	}
4287 	min = simple_strtoul(buf, &e, 10);
4288 	if (buf == e || (*e && *e != '\n') || min <= 0)
4289 		return -EINVAL;
4290 	mddev->sync_speed_min = min;
4291 	return len;
4292 }
4293 
4294 static struct md_sysfs_entry md_sync_min =
4295 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4296 
4297 static ssize_t
4298 sync_max_show(struct mddev *mddev, char *page)
4299 {
4300 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
4301 		       mddev->sync_speed_max ? "local": "system");
4302 }
4303 
4304 static ssize_t
4305 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4306 {
4307 	int max;
4308 	char *e;
4309 	if (strncmp(buf, "system", 6)==0) {
4310 		mddev->sync_speed_max = 0;
4311 		return len;
4312 	}
4313 	max = simple_strtoul(buf, &e, 10);
4314 	if (buf == e || (*e && *e != '\n') || max <= 0)
4315 		return -EINVAL;
4316 	mddev->sync_speed_max = max;
4317 	return len;
4318 }
4319 
4320 static struct md_sysfs_entry md_sync_max =
4321 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4322 
4323 static ssize_t
4324 degraded_show(struct mddev *mddev, char *page)
4325 {
4326 	return sprintf(page, "%d\n", mddev->degraded);
4327 }
4328 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4329 
4330 static ssize_t
4331 sync_force_parallel_show(struct mddev *mddev, char *page)
4332 {
4333 	return sprintf(page, "%d\n", mddev->parallel_resync);
4334 }
4335 
4336 static ssize_t
4337 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4338 {
4339 	long n;
4340 
4341 	if (strict_strtol(buf, 10, &n))
4342 		return -EINVAL;
4343 
4344 	if (n != 0 && n != 1)
4345 		return -EINVAL;
4346 
4347 	mddev->parallel_resync = n;
4348 
4349 	if (mddev->sync_thread)
4350 		wake_up(&resync_wait);
4351 
4352 	return len;
4353 }
4354 
4355 /* force parallel resync, even with shared block devices */
4356 static struct md_sysfs_entry md_sync_force_parallel =
4357 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4358        sync_force_parallel_show, sync_force_parallel_store);
4359 
4360 static ssize_t
4361 sync_speed_show(struct mddev *mddev, char *page)
4362 {
4363 	unsigned long resync, dt, db;
4364 	if (mddev->curr_resync == 0)
4365 		return sprintf(page, "none\n");
4366 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4367 	dt = (jiffies - mddev->resync_mark) / HZ;
4368 	if (!dt) dt++;
4369 	db = resync - mddev->resync_mark_cnt;
4370 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4371 }
4372 
4373 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4374 
4375 static ssize_t
4376 sync_completed_show(struct mddev *mddev, char *page)
4377 {
4378 	unsigned long long max_sectors, resync;
4379 
4380 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4381 		return sprintf(page, "none\n");
4382 
4383 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4384 	    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4385 		max_sectors = mddev->resync_max_sectors;
4386 	else
4387 		max_sectors = mddev->dev_sectors;
4388 
4389 	resync = mddev->curr_resync_completed;
4390 	return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4391 }
4392 
4393 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4394 
4395 static ssize_t
4396 min_sync_show(struct mddev *mddev, char *page)
4397 {
4398 	return sprintf(page, "%llu\n",
4399 		       (unsigned long long)mddev->resync_min);
4400 }
4401 static ssize_t
4402 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4403 {
4404 	unsigned long long min;
4405 	if (strict_strtoull(buf, 10, &min))
4406 		return -EINVAL;
4407 	if (min > mddev->resync_max)
4408 		return -EINVAL;
4409 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4410 		return -EBUSY;
4411 
4412 	/* Must be a multiple of chunk_size */
4413 	if (mddev->chunk_sectors) {
4414 		sector_t temp = min;
4415 		if (sector_div(temp, mddev->chunk_sectors))
4416 			return -EINVAL;
4417 	}
4418 	mddev->resync_min = min;
4419 
4420 	return len;
4421 }
4422 
4423 static struct md_sysfs_entry md_min_sync =
4424 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4425 
4426 static ssize_t
4427 max_sync_show(struct mddev *mddev, char *page)
4428 {
4429 	if (mddev->resync_max == MaxSector)
4430 		return sprintf(page, "max\n");
4431 	else
4432 		return sprintf(page, "%llu\n",
4433 			       (unsigned long long)mddev->resync_max);
4434 }
4435 static ssize_t
4436 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4437 {
4438 	if (strncmp(buf, "max", 3) == 0)
4439 		mddev->resync_max = MaxSector;
4440 	else {
4441 		unsigned long long max;
4442 		if (strict_strtoull(buf, 10, &max))
4443 			return -EINVAL;
4444 		if (max < mddev->resync_min)
4445 			return -EINVAL;
4446 		if (max < mddev->resync_max &&
4447 		    mddev->ro == 0 &&
4448 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4449 			return -EBUSY;
4450 
4451 		/* Must be a multiple of chunk_size */
4452 		if (mddev->chunk_sectors) {
4453 			sector_t temp = max;
4454 			if (sector_div(temp, mddev->chunk_sectors))
4455 				return -EINVAL;
4456 		}
4457 		mddev->resync_max = max;
4458 	}
4459 	wake_up(&mddev->recovery_wait);
4460 	return len;
4461 }
4462 
4463 static struct md_sysfs_entry md_max_sync =
4464 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4465 
4466 static ssize_t
4467 suspend_lo_show(struct mddev *mddev, char *page)
4468 {
4469 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4470 }
4471 
4472 static ssize_t
4473 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4474 {
4475 	char *e;
4476 	unsigned long long new = simple_strtoull(buf, &e, 10);
4477 	unsigned long long old = mddev->suspend_lo;
4478 
4479 	if (mddev->pers == NULL ||
4480 	    mddev->pers->quiesce == NULL)
4481 		return -EINVAL;
4482 	if (buf == e || (*e && *e != '\n'))
4483 		return -EINVAL;
4484 
4485 	mddev->suspend_lo = new;
4486 	if (new >= old)
4487 		/* Shrinking suspended region */
4488 		mddev->pers->quiesce(mddev, 2);
4489 	else {
4490 		/* Expanding suspended region - need to wait */
4491 		mddev->pers->quiesce(mddev, 1);
4492 		mddev->pers->quiesce(mddev, 0);
4493 	}
4494 	return len;
4495 }
4496 static struct md_sysfs_entry md_suspend_lo =
4497 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4498 
4499 
4500 static ssize_t
4501 suspend_hi_show(struct mddev *mddev, char *page)
4502 {
4503 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4504 }
4505 
4506 static ssize_t
4507 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4508 {
4509 	char *e;
4510 	unsigned long long new = simple_strtoull(buf, &e, 10);
4511 	unsigned long long old = mddev->suspend_hi;
4512 
4513 	if (mddev->pers == NULL ||
4514 	    mddev->pers->quiesce == NULL)
4515 		return -EINVAL;
4516 	if (buf == e || (*e && *e != '\n'))
4517 		return -EINVAL;
4518 
4519 	mddev->suspend_hi = new;
4520 	if (new <= old)
4521 		/* Shrinking suspended region */
4522 		mddev->pers->quiesce(mddev, 2);
4523 	else {
4524 		/* Expanding suspended region - need to wait */
4525 		mddev->pers->quiesce(mddev, 1);
4526 		mddev->pers->quiesce(mddev, 0);
4527 	}
4528 	return len;
4529 }
4530 static struct md_sysfs_entry md_suspend_hi =
4531 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4532 
4533 static ssize_t
4534 reshape_position_show(struct mddev *mddev, char *page)
4535 {
4536 	if (mddev->reshape_position != MaxSector)
4537 		return sprintf(page, "%llu\n",
4538 			       (unsigned long long)mddev->reshape_position);
4539 	strcpy(page, "none\n");
4540 	return 5;
4541 }
4542 
4543 static ssize_t
4544 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4545 {
4546 	struct md_rdev *rdev;
4547 	char *e;
4548 	unsigned long long new = simple_strtoull(buf, &e, 10);
4549 	if (mddev->pers)
4550 		return -EBUSY;
4551 	if (buf == e || (*e && *e != '\n'))
4552 		return -EINVAL;
4553 	mddev->reshape_position = new;
4554 	mddev->delta_disks = 0;
4555 	mddev->reshape_backwards = 0;
4556 	mddev->new_level = mddev->level;
4557 	mddev->new_layout = mddev->layout;
4558 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4559 	rdev_for_each(rdev, mddev)
4560 		rdev->new_data_offset = rdev->data_offset;
4561 	return len;
4562 }
4563 
4564 static struct md_sysfs_entry md_reshape_position =
4565 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4566        reshape_position_store);
4567 
4568 static ssize_t
4569 reshape_direction_show(struct mddev *mddev, char *page)
4570 {
4571 	return sprintf(page, "%s\n",
4572 		       mddev->reshape_backwards ? "backwards" : "forwards");
4573 }
4574 
4575 static ssize_t
4576 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4577 {
4578 	int backwards = 0;
4579 	if (cmd_match(buf, "forwards"))
4580 		backwards = 0;
4581 	else if (cmd_match(buf, "backwards"))
4582 		backwards = 1;
4583 	else
4584 		return -EINVAL;
4585 	if (mddev->reshape_backwards == backwards)
4586 		return len;
4587 
4588 	/* check if we are allowed to change */
4589 	if (mddev->delta_disks)
4590 		return -EBUSY;
4591 
4592 	if (mddev->persistent &&
4593 	    mddev->major_version == 0)
4594 		return -EINVAL;
4595 
4596 	mddev->reshape_backwards = backwards;
4597 	return len;
4598 }
4599 
4600 static struct md_sysfs_entry md_reshape_direction =
4601 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4602        reshape_direction_store);
4603 
4604 static ssize_t
4605 array_size_show(struct mddev *mddev, char *page)
4606 {
4607 	if (mddev->external_size)
4608 		return sprintf(page, "%llu\n",
4609 			       (unsigned long long)mddev->array_sectors/2);
4610 	else
4611 		return sprintf(page, "default\n");
4612 }
4613 
4614 static ssize_t
4615 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4616 {
4617 	sector_t sectors;
4618 
4619 	if (strncmp(buf, "default", 7) == 0) {
4620 		if (mddev->pers)
4621 			sectors = mddev->pers->size(mddev, 0, 0);
4622 		else
4623 			sectors = mddev->array_sectors;
4624 
4625 		mddev->external_size = 0;
4626 	} else {
4627 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4628 			return -EINVAL;
4629 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4630 			return -E2BIG;
4631 
4632 		mddev->external_size = 1;
4633 	}
4634 
4635 	mddev->array_sectors = sectors;
4636 	if (mddev->pers) {
4637 		set_capacity(mddev->gendisk, mddev->array_sectors);
4638 		revalidate_disk(mddev->gendisk);
4639 	}
4640 	return len;
4641 }
4642 
4643 static struct md_sysfs_entry md_array_size =
4644 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4645        array_size_store);
4646 
4647 static struct attribute *md_default_attrs[] = {
4648 	&md_level.attr,
4649 	&md_layout.attr,
4650 	&md_raid_disks.attr,
4651 	&md_chunk_size.attr,
4652 	&md_size.attr,
4653 	&md_resync_start.attr,
4654 	&md_metadata.attr,
4655 	&md_new_device.attr,
4656 	&md_safe_delay.attr,
4657 	&md_array_state.attr,
4658 	&md_reshape_position.attr,
4659 	&md_reshape_direction.attr,
4660 	&md_array_size.attr,
4661 	&max_corr_read_errors.attr,
4662 	NULL,
4663 };
4664 
4665 static struct attribute *md_redundancy_attrs[] = {
4666 	&md_scan_mode.attr,
4667 	&md_mismatches.attr,
4668 	&md_sync_min.attr,
4669 	&md_sync_max.attr,
4670 	&md_sync_speed.attr,
4671 	&md_sync_force_parallel.attr,
4672 	&md_sync_completed.attr,
4673 	&md_min_sync.attr,
4674 	&md_max_sync.attr,
4675 	&md_suspend_lo.attr,
4676 	&md_suspend_hi.attr,
4677 	&md_bitmap.attr,
4678 	&md_degraded.attr,
4679 	NULL,
4680 };
4681 static struct attribute_group md_redundancy_group = {
4682 	.name = NULL,
4683 	.attrs = md_redundancy_attrs,
4684 };
4685 
4686 
4687 static ssize_t
4688 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4689 {
4690 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4691 	struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4692 	ssize_t rv;
4693 
4694 	if (!entry->show)
4695 		return -EIO;
4696 	spin_lock(&all_mddevs_lock);
4697 	if (list_empty(&mddev->all_mddevs)) {
4698 		spin_unlock(&all_mddevs_lock);
4699 		return -EBUSY;
4700 	}
4701 	mddev_get(mddev);
4702 	spin_unlock(&all_mddevs_lock);
4703 
4704 	rv = mddev_lock(mddev);
4705 	if (!rv) {
4706 		rv = entry->show(mddev, page);
4707 		mddev_unlock(mddev);
4708 	}
4709 	mddev_put(mddev);
4710 	return rv;
4711 }
4712 
4713 static ssize_t
4714 md_attr_store(struct kobject *kobj, struct attribute *attr,
4715 	      const char *page, size_t length)
4716 {
4717 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4718 	struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4719 	ssize_t rv;
4720 
4721 	if (!entry->store)
4722 		return -EIO;
4723 	if (!capable(CAP_SYS_ADMIN))
4724 		return -EACCES;
4725 	spin_lock(&all_mddevs_lock);
4726 	if (list_empty(&mddev->all_mddevs)) {
4727 		spin_unlock(&all_mddevs_lock);
4728 		return -EBUSY;
4729 	}
4730 	mddev_get(mddev);
4731 	spin_unlock(&all_mddevs_lock);
4732 	rv = mddev_lock(mddev);
4733 	if (!rv) {
4734 		rv = entry->store(mddev, page, length);
4735 		mddev_unlock(mddev);
4736 	}
4737 	mddev_put(mddev);
4738 	return rv;
4739 }
4740 
4741 static void md_free(struct kobject *ko)
4742 {
4743 	struct mddev *mddev = container_of(ko, struct mddev, kobj);
4744 
4745 	if (mddev->sysfs_state)
4746 		sysfs_put(mddev->sysfs_state);
4747 
4748 	if (mddev->gendisk) {
4749 		del_gendisk(mddev->gendisk);
4750 		put_disk(mddev->gendisk);
4751 	}
4752 	if (mddev->queue)
4753 		blk_cleanup_queue(mddev->queue);
4754 
4755 	kfree(mddev);
4756 }
4757 
4758 static const struct sysfs_ops md_sysfs_ops = {
4759 	.show	= md_attr_show,
4760 	.store	= md_attr_store,
4761 };
4762 static struct kobj_type md_ktype = {
4763 	.release	= md_free,
4764 	.sysfs_ops	= &md_sysfs_ops,
4765 	.default_attrs	= md_default_attrs,
4766 };
4767 
4768 int mdp_major = 0;
4769 
4770 static void mddev_delayed_delete(struct work_struct *ws)
4771 {
4772 	struct mddev *mddev = container_of(ws, struct mddev, del_work);
4773 
4774 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4775 	kobject_del(&mddev->kobj);
4776 	kobject_put(&mddev->kobj);
4777 }
4778 
4779 static int md_alloc(dev_t dev, char *name)
4780 {
4781 	static DEFINE_MUTEX(disks_mutex);
4782 	struct mddev *mddev = mddev_find(dev);
4783 	struct gendisk *disk;
4784 	int partitioned;
4785 	int shift;
4786 	int unit;
4787 	int error;
4788 
4789 	if (!mddev)
4790 		return -ENODEV;
4791 
4792 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4793 	shift = partitioned ? MdpMinorShift : 0;
4794 	unit = MINOR(mddev->unit) >> shift;
4795 
4796 	/* wait for any previous instance of this device to be
4797 	 * completely removed (mddev_delayed_delete).
4798 	 */
4799 	flush_workqueue(md_misc_wq);
4800 
4801 	mutex_lock(&disks_mutex);
4802 	error = -EEXIST;
4803 	if (mddev->gendisk)
4804 		goto abort;
4805 
4806 	if (name) {
4807 		/* Need to ensure that 'name' is not a duplicate.
4808 		 */
4809 		struct mddev *mddev2;
4810 		spin_lock(&all_mddevs_lock);
4811 
4812 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4813 			if (mddev2->gendisk &&
4814 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4815 				spin_unlock(&all_mddevs_lock);
4816 				goto abort;
4817 			}
4818 		spin_unlock(&all_mddevs_lock);
4819 	}
4820 
4821 	error = -ENOMEM;
4822 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4823 	if (!mddev->queue)
4824 		goto abort;
4825 	mddev->queue->queuedata = mddev;
4826 
4827 	blk_queue_make_request(mddev->queue, md_make_request);
4828 	blk_set_stacking_limits(&mddev->queue->limits);
4829 
4830 	disk = alloc_disk(1 << shift);
4831 	if (!disk) {
4832 		blk_cleanup_queue(mddev->queue);
4833 		mddev->queue = NULL;
4834 		goto abort;
4835 	}
4836 	disk->major = MAJOR(mddev->unit);
4837 	disk->first_minor = unit << shift;
4838 	if (name)
4839 		strcpy(disk->disk_name, name);
4840 	else if (partitioned)
4841 		sprintf(disk->disk_name, "md_d%d", unit);
4842 	else
4843 		sprintf(disk->disk_name, "md%d", unit);
4844 	disk->fops = &md_fops;
4845 	disk->private_data = mddev;
4846 	disk->queue = mddev->queue;
4847 	blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4848 	/* Allow extended partitions.  This makes the
4849 	 * 'mdp' device redundant, but we can't really
4850 	 * remove it now.
4851 	 */
4852 	disk->flags |= GENHD_FL_EXT_DEVT;
4853 	mddev->gendisk = disk;
4854 	/* As soon as we call add_disk(), another thread could get
4855 	 * through to md_open, so make sure it doesn't get too far
4856 	 */
4857 	mutex_lock(&mddev->open_mutex);
4858 	add_disk(disk);
4859 
4860 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4861 				     &disk_to_dev(disk)->kobj, "%s", "md");
4862 	if (error) {
4863 		/* This isn't possible, but as kobject_init_and_add is marked
4864 		 * __must_check, we must do something with the result
4865 		 */
4866 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4867 		       disk->disk_name);
4868 		error = 0;
4869 	}
4870 	if (mddev->kobj.sd &&
4871 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4872 		printk(KERN_DEBUG "pointless warning\n");
4873 	mutex_unlock(&mddev->open_mutex);
4874  abort:
4875 	mutex_unlock(&disks_mutex);
4876 	if (!error && mddev->kobj.sd) {
4877 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4878 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4879 	}
4880 	mddev_put(mddev);
4881 	return error;
4882 }
4883 
4884 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4885 {
4886 	md_alloc(dev, NULL);
4887 	return NULL;
4888 }
4889 
4890 static int add_named_array(const char *val, struct kernel_param *kp)
4891 {
4892 	/* val must be "md_*" where * is not all digits.
4893 	 * We allocate an array with a large free minor number, and
4894 	 * set the name to val.  val must not already be an active name.
4895 	 */
4896 	int len = strlen(val);
4897 	char buf[DISK_NAME_LEN];
4898 
4899 	while (len && val[len-1] == '\n')
4900 		len--;
4901 	if (len >= DISK_NAME_LEN)
4902 		return -E2BIG;
4903 	strlcpy(buf, val, len+1);
4904 	if (strncmp(buf, "md_", 3) != 0)
4905 		return -EINVAL;
4906 	return md_alloc(0, buf);
4907 }
4908 
4909 static void md_safemode_timeout(unsigned long data)
4910 {
4911 	struct mddev *mddev = (struct mddev *) data;
4912 
4913 	if (!atomic_read(&mddev->writes_pending)) {
4914 		mddev->safemode = 1;
4915 		if (mddev->external)
4916 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4917 	}
4918 	md_wakeup_thread(mddev->thread);
4919 }
4920 
4921 static int start_dirty_degraded;
4922 
4923 int md_run(struct mddev *mddev)
4924 {
4925 	int err;
4926 	struct md_rdev *rdev;
4927 	struct md_personality *pers;
4928 
4929 	if (list_empty(&mddev->disks))
4930 		/* cannot run an array with no devices.. */
4931 		return -EINVAL;
4932 
4933 	if (mddev->pers)
4934 		return -EBUSY;
4935 	/* Cannot run until previous stop completes properly */
4936 	if (mddev->sysfs_active)
4937 		return -EBUSY;
4938 
4939 	/*
4940 	 * Analyze all RAID superblock(s)
4941 	 */
4942 	if (!mddev->raid_disks) {
4943 		if (!mddev->persistent)
4944 			return -EINVAL;
4945 		analyze_sbs(mddev);
4946 	}
4947 
4948 	if (mddev->level != LEVEL_NONE)
4949 		request_module("md-level-%d", mddev->level);
4950 	else if (mddev->clevel[0])
4951 		request_module("md-%s", mddev->clevel);
4952 
4953 	/*
4954 	 * Drop all container device buffers, from now on
4955 	 * the only valid external interface is through the md
4956 	 * device.
4957 	 */
4958 	rdev_for_each(rdev, mddev) {
4959 		if (test_bit(Faulty, &rdev->flags))
4960 			continue;
4961 		sync_blockdev(rdev->bdev);
4962 		invalidate_bdev(rdev->bdev);
4963 
4964 		/* perform some consistency tests on the device.
4965 		 * We don't want the data to overlap the metadata,
4966 		 * Internal Bitmap issues have been handled elsewhere.
4967 		 */
4968 		if (rdev->meta_bdev) {
4969 			/* Nothing to check */;
4970 		} else if (rdev->data_offset < rdev->sb_start) {
4971 			if (mddev->dev_sectors &&
4972 			    rdev->data_offset + mddev->dev_sectors
4973 			    > rdev->sb_start) {
4974 				printk("md: %s: data overlaps metadata\n",
4975 				       mdname(mddev));
4976 				return -EINVAL;
4977 			}
4978 		} else {
4979 			if (rdev->sb_start + rdev->sb_size/512
4980 			    > rdev->data_offset) {
4981 				printk("md: %s: metadata overlaps data\n",
4982 				       mdname(mddev));
4983 				return -EINVAL;
4984 			}
4985 		}
4986 		sysfs_notify_dirent_safe(rdev->sysfs_state);
4987 	}
4988 
4989 	if (mddev->bio_set == NULL)
4990 		mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
4991 
4992 	spin_lock(&pers_lock);
4993 	pers = find_pers(mddev->level, mddev->clevel);
4994 	if (!pers || !try_module_get(pers->owner)) {
4995 		spin_unlock(&pers_lock);
4996 		if (mddev->level != LEVEL_NONE)
4997 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4998 			       mddev->level);
4999 		else
5000 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5001 			       mddev->clevel);
5002 		return -EINVAL;
5003 	}
5004 	mddev->pers = pers;
5005 	spin_unlock(&pers_lock);
5006 	if (mddev->level != pers->level) {
5007 		mddev->level = pers->level;
5008 		mddev->new_level = pers->level;
5009 	}
5010 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5011 
5012 	if (mddev->reshape_position != MaxSector &&
5013 	    pers->start_reshape == NULL) {
5014 		/* This personality cannot handle reshaping... */
5015 		mddev->pers = NULL;
5016 		module_put(pers->owner);
5017 		return -EINVAL;
5018 	}
5019 
5020 	if (pers->sync_request) {
5021 		/* Warn if this is a potentially silly
5022 		 * configuration.
5023 		 */
5024 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5025 		struct md_rdev *rdev2;
5026 		int warned = 0;
5027 
5028 		rdev_for_each(rdev, mddev)
5029 			rdev_for_each(rdev2, mddev) {
5030 				if (rdev < rdev2 &&
5031 				    rdev->bdev->bd_contains ==
5032 				    rdev2->bdev->bd_contains) {
5033 					printk(KERN_WARNING
5034 					       "%s: WARNING: %s appears to be"
5035 					       " on the same physical disk as"
5036 					       " %s.\n",
5037 					       mdname(mddev),
5038 					       bdevname(rdev->bdev,b),
5039 					       bdevname(rdev2->bdev,b2));
5040 					warned = 1;
5041 				}
5042 			}
5043 
5044 		if (warned)
5045 			printk(KERN_WARNING
5046 			       "True protection against single-disk"
5047 			       " failure might be compromised.\n");
5048 	}
5049 
5050 	mddev->recovery = 0;
5051 	/* may be over-ridden by personality */
5052 	mddev->resync_max_sectors = mddev->dev_sectors;
5053 
5054 	mddev->ok_start_degraded = start_dirty_degraded;
5055 
5056 	if (start_readonly && mddev->ro == 0)
5057 		mddev->ro = 2; /* read-only, but switch on first write */
5058 
5059 	err = mddev->pers->run(mddev);
5060 	if (err)
5061 		printk(KERN_ERR "md: pers->run() failed ...\n");
5062 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
5063 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5064 			  " but 'external_size' not in effect?\n", __func__);
5065 		printk(KERN_ERR
5066 		       "md: invalid array_size %llu > default size %llu\n",
5067 		       (unsigned long long)mddev->array_sectors / 2,
5068 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
5069 		err = -EINVAL;
5070 		mddev->pers->stop(mddev);
5071 	}
5072 	if (err == 0 && mddev->pers->sync_request &&
5073 	    (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5074 		err = bitmap_create(mddev);
5075 		if (err) {
5076 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5077 			       mdname(mddev), err);
5078 			mddev->pers->stop(mddev);
5079 		}
5080 	}
5081 	if (err) {
5082 		module_put(mddev->pers->owner);
5083 		mddev->pers = NULL;
5084 		bitmap_destroy(mddev);
5085 		return err;
5086 	}
5087 	if (mddev->pers->sync_request) {
5088 		if (mddev->kobj.sd &&
5089 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5090 			printk(KERN_WARNING
5091 			       "md: cannot register extra attributes for %s\n",
5092 			       mdname(mddev));
5093 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5094 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
5095 		mddev->ro = 0;
5096 
5097  	atomic_set(&mddev->writes_pending,0);
5098 	atomic_set(&mddev->max_corr_read_errors,
5099 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5100 	mddev->safemode = 0;
5101 	mddev->safemode_timer.function = md_safemode_timeout;
5102 	mddev->safemode_timer.data = (unsigned long) mddev;
5103 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5104 	mddev->in_sync = 1;
5105 	smp_wmb();
5106 	mddev->ready = 1;
5107 	rdev_for_each(rdev, mddev)
5108 		if (rdev->raid_disk >= 0)
5109 			if (sysfs_link_rdev(mddev, rdev))
5110 				/* failure here is OK */;
5111 
5112 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5113 
5114 	if (mddev->flags)
5115 		md_update_sb(mddev, 0);
5116 
5117 	md_new_event(mddev);
5118 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5119 	sysfs_notify_dirent_safe(mddev->sysfs_action);
5120 	sysfs_notify(&mddev->kobj, NULL, "degraded");
5121 	return 0;
5122 }
5123 EXPORT_SYMBOL_GPL(md_run);
5124 
5125 static int do_md_run(struct mddev *mddev)
5126 {
5127 	int err;
5128 
5129 	err = md_run(mddev);
5130 	if (err)
5131 		goto out;
5132 	err = bitmap_load(mddev);
5133 	if (err) {
5134 		bitmap_destroy(mddev);
5135 		goto out;
5136 	}
5137 
5138 	md_wakeup_thread(mddev->thread);
5139 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5140 
5141 	set_capacity(mddev->gendisk, mddev->array_sectors);
5142 	revalidate_disk(mddev->gendisk);
5143 	mddev->changed = 1;
5144 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5145 out:
5146 	return err;
5147 }
5148 
5149 static int restart_array(struct mddev *mddev)
5150 {
5151 	struct gendisk *disk = mddev->gendisk;
5152 
5153 	/* Complain if it has no devices */
5154 	if (list_empty(&mddev->disks))
5155 		return -ENXIO;
5156 	if (!mddev->pers)
5157 		return -EINVAL;
5158 	if (!mddev->ro)
5159 		return -EBUSY;
5160 	mddev->safemode = 0;
5161 	mddev->ro = 0;
5162 	set_disk_ro(disk, 0);
5163 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
5164 		mdname(mddev));
5165 	/* Kick recovery or resync if necessary */
5166 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5167 	md_wakeup_thread(mddev->thread);
5168 	md_wakeup_thread(mddev->sync_thread);
5169 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5170 	return 0;
5171 }
5172 
5173 /* similar to deny_write_access, but accounts for our holding a reference
5174  * to the file ourselves */
5175 static int deny_bitmap_write_access(struct file * file)
5176 {
5177 	struct inode *inode = file->f_mapping->host;
5178 
5179 	spin_lock(&inode->i_lock);
5180 	if (atomic_read(&inode->i_writecount) > 1) {
5181 		spin_unlock(&inode->i_lock);
5182 		return -ETXTBSY;
5183 	}
5184 	atomic_set(&inode->i_writecount, -1);
5185 	spin_unlock(&inode->i_lock);
5186 
5187 	return 0;
5188 }
5189 
5190 void restore_bitmap_write_access(struct file *file)
5191 {
5192 	struct inode *inode = file->f_mapping->host;
5193 
5194 	spin_lock(&inode->i_lock);
5195 	atomic_set(&inode->i_writecount, 1);
5196 	spin_unlock(&inode->i_lock);
5197 }
5198 
5199 static void md_clean(struct mddev *mddev)
5200 {
5201 	mddev->array_sectors = 0;
5202 	mddev->external_size = 0;
5203 	mddev->dev_sectors = 0;
5204 	mddev->raid_disks = 0;
5205 	mddev->recovery_cp = 0;
5206 	mddev->resync_min = 0;
5207 	mddev->resync_max = MaxSector;
5208 	mddev->reshape_position = MaxSector;
5209 	mddev->external = 0;
5210 	mddev->persistent = 0;
5211 	mddev->level = LEVEL_NONE;
5212 	mddev->clevel[0] = 0;
5213 	mddev->flags = 0;
5214 	mddev->ro = 0;
5215 	mddev->metadata_type[0] = 0;
5216 	mddev->chunk_sectors = 0;
5217 	mddev->ctime = mddev->utime = 0;
5218 	mddev->layout = 0;
5219 	mddev->max_disks = 0;
5220 	mddev->events = 0;
5221 	mddev->can_decrease_events = 0;
5222 	mddev->delta_disks = 0;
5223 	mddev->reshape_backwards = 0;
5224 	mddev->new_level = LEVEL_NONE;
5225 	mddev->new_layout = 0;
5226 	mddev->new_chunk_sectors = 0;
5227 	mddev->curr_resync = 0;
5228 	mddev->resync_mismatches = 0;
5229 	mddev->suspend_lo = mddev->suspend_hi = 0;
5230 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
5231 	mddev->recovery = 0;
5232 	mddev->in_sync = 0;
5233 	mddev->changed = 0;
5234 	mddev->degraded = 0;
5235 	mddev->safemode = 0;
5236 	mddev->merge_check_needed = 0;
5237 	mddev->bitmap_info.offset = 0;
5238 	mddev->bitmap_info.default_offset = 0;
5239 	mddev->bitmap_info.default_space = 0;
5240 	mddev->bitmap_info.chunksize = 0;
5241 	mddev->bitmap_info.daemon_sleep = 0;
5242 	mddev->bitmap_info.max_write_behind = 0;
5243 }
5244 
5245 static void __md_stop_writes(struct mddev *mddev)
5246 {
5247 	if (mddev->sync_thread) {
5248 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5249 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5250 		reap_sync_thread(mddev);
5251 	}
5252 
5253 	del_timer_sync(&mddev->safemode_timer);
5254 
5255 	bitmap_flush(mddev);
5256 	md_super_wait(mddev);
5257 
5258 	if (!mddev->in_sync || mddev->flags) {
5259 		/* mark array as shutdown cleanly */
5260 		mddev->in_sync = 1;
5261 		md_update_sb(mddev, 1);
5262 	}
5263 }
5264 
5265 void md_stop_writes(struct mddev *mddev)
5266 {
5267 	mddev_lock(mddev);
5268 	__md_stop_writes(mddev);
5269 	mddev_unlock(mddev);
5270 }
5271 EXPORT_SYMBOL_GPL(md_stop_writes);
5272 
5273 void md_stop(struct mddev *mddev)
5274 {
5275 	mddev->ready = 0;
5276 	mddev->pers->stop(mddev);
5277 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
5278 		mddev->to_remove = &md_redundancy_group;
5279 	module_put(mddev->pers->owner);
5280 	mddev->pers = NULL;
5281 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5282 }
5283 EXPORT_SYMBOL_GPL(md_stop);
5284 
5285 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5286 {
5287 	int err = 0;
5288 	mutex_lock(&mddev->open_mutex);
5289 	if (atomic_read(&mddev->openers) > !!bdev) {
5290 		printk("md: %s still in use.\n",mdname(mddev));
5291 		err = -EBUSY;
5292 		goto out;
5293 	}
5294 	if (bdev)
5295 		sync_blockdev(bdev);
5296 	if (mddev->pers) {
5297 		__md_stop_writes(mddev);
5298 
5299 		err  = -ENXIO;
5300 		if (mddev->ro==1)
5301 			goto out;
5302 		mddev->ro = 1;
5303 		set_disk_ro(mddev->gendisk, 1);
5304 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5305 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5306 		err = 0;
5307 	}
5308 out:
5309 	mutex_unlock(&mddev->open_mutex);
5310 	return err;
5311 }
5312 
5313 /* mode:
5314  *   0 - completely stop and dis-assemble array
5315  *   2 - stop but do not disassemble array
5316  */
5317 static int do_md_stop(struct mddev * mddev, int mode,
5318 		      struct block_device *bdev)
5319 {
5320 	struct gendisk *disk = mddev->gendisk;
5321 	struct md_rdev *rdev;
5322 
5323 	mutex_lock(&mddev->open_mutex);
5324 	if (atomic_read(&mddev->openers) > !!bdev ||
5325 	    mddev->sysfs_active) {
5326 		printk("md: %s still in use.\n",mdname(mddev));
5327 		mutex_unlock(&mddev->open_mutex);
5328 		return -EBUSY;
5329 	}
5330 	if (bdev)
5331 		/* It is possible IO was issued on some other
5332 		 * open file which was closed before we took ->open_mutex.
5333 		 * As that was not the last close __blkdev_put will not
5334 		 * have called sync_blockdev, so we must.
5335 		 */
5336 		sync_blockdev(bdev);
5337 
5338 	if (mddev->pers) {
5339 		if (mddev->ro)
5340 			set_disk_ro(disk, 0);
5341 
5342 		__md_stop_writes(mddev);
5343 		md_stop(mddev);
5344 		mddev->queue->merge_bvec_fn = NULL;
5345 		mddev->queue->backing_dev_info.congested_fn = NULL;
5346 
5347 		/* tell userspace to handle 'inactive' */
5348 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5349 
5350 		rdev_for_each(rdev, mddev)
5351 			if (rdev->raid_disk >= 0)
5352 				sysfs_unlink_rdev(mddev, rdev);
5353 
5354 		set_capacity(disk, 0);
5355 		mutex_unlock(&mddev->open_mutex);
5356 		mddev->changed = 1;
5357 		revalidate_disk(disk);
5358 
5359 		if (mddev->ro)
5360 			mddev->ro = 0;
5361 	} else
5362 		mutex_unlock(&mddev->open_mutex);
5363 	/*
5364 	 * Free resources if final stop
5365 	 */
5366 	if (mode == 0) {
5367 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5368 
5369 		bitmap_destroy(mddev);
5370 		if (mddev->bitmap_info.file) {
5371 			restore_bitmap_write_access(mddev->bitmap_info.file);
5372 			fput(mddev->bitmap_info.file);
5373 			mddev->bitmap_info.file = NULL;
5374 		}
5375 		mddev->bitmap_info.offset = 0;
5376 
5377 		export_array(mddev);
5378 
5379 		md_clean(mddev);
5380 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5381 		if (mddev->hold_active == UNTIL_STOP)
5382 			mddev->hold_active = 0;
5383 	}
5384 	blk_integrity_unregister(disk);
5385 	md_new_event(mddev);
5386 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5387 	return 0;
5388 }
5389 
5390 #ifndef MODULE
5391 static void autorun_array(struct mddev *mddev)
5392 {
5393 	struct md_rdev *rdev;
5394 	int err;
5395 
5396 	if (list_empty(&mddev->disks))
5397 		return;
5398 
5399 	printk(KERN_INFO "md: running: ");
5400 
5401 	rdev_for_each(rdev, mddev) {
5402 		char b[BDEVNAME_SIZE];
5403 		printk("<%s>", bdevname(rdev->bdev,b));
5404 	}
5405 	printk("\n");
5406 
5407 	err = do_md_run(mddev);
5408 	if (err) {
5409 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5410 		do_md_stop(mddev, 0, NULL);
5411 	}
5412 }
5413 
5414 /*
5415  * lets try to run arrays based on all disks that have arrived
5416  * until now. (those are in pending_raid_disks)
5417  *
5418  * the method: pick the first pending disk, collect all disks with
5419  * the same UUID, remove all from the pending list and put them into
5420  * the 'same_array' list. Then order this list based on superblock
5421  * update time (freshest comes first), kick out 'old' disks and
5422  * compare superblocks. If everything's fine then run it.
5423  *
5424  * If "unit" is allocated, then bump its reference count
5425  */
5426 static void autorun_devices(int part)
5427 {
5428 	struct md_rdev *rdev0, *rdev, *tmp;
5429 	struct mddev *mddev;
5430 	char b[BDEVNAME_SIZE];
5431 
5432 	printk(KERN_INFO "md: autorun ...\n");
5433 	while (!list_empty(&pending_raid_disks)) {
5434 		int unit;
5435 		dev_t dev;
5436 		LIST_HEAD(candidates);
5437 		rdev0 = list_entry(pending_raid_disks.next,
5438 					 struct md_rdev, same_set);
5439 
5440 		printk(KERN_INFO "md: considering %s ...\n",
5441 			bdevname(rdev0->bdev,b));
5442 		INIT_LIST_HEAD(&candidates);
5443 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5444 			if (super_90_load(rdev, rdev0, 0) >= 0) {
5445 				printk(KERN_INFO "md:  adding %s ...\n",
5446 					bdevname(rdev->bdev,b));
5447 				list_move(&rdev->same_set, &candidates);
5448 			}
5449 		/*
5450 		 * now we have a set of devices, with all of them having
5451 		 * mostly sane superblocks. It's time to allocate the
5452 		 * mddev.
5453 		 */
5454 		if (part) {
5455 			dev = MKDEV(mdp_major,
5456 				    rdev0->preferred_minor << MdpMinorShift);
5457 			unit = MINOR(dev) >> MdpMinorShift;
5458 		} else {
5459 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5460 			unit = MINOR(dev);
5461 		}
5462 		if (rdev0->preferred_minor != unit) {
5463 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5464 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5465 			break;
5466 		}
5467 
5468 		md_probe(dev, NULL, NULL);
5469 		mddev = mddev_find(dev);
5470 		if (!mddev || !mddev->gendisk) {
5471 			if (mddev)
5472 				mddev_put(mddev);
5473 			printk(KERN_ERR
5474 				"md: cannot allocate memory for md drive.\n");
5475 			break;
5476 		}
5477 		if (mddev_lock(mddev))
5478 			printk(KERN_WARNING "md: %s locked, cannot run\n",
5479 			       mdname(mddev));
5480 		else if (mddev->raid_disks || mddev->major_version
5481 			 || !list_empty(&mddev->disks)) {
5482 			printk(KERN_WARNING
5483 				"md: %s already running, cannot run %s\n",
5484 				mdname(mddev), bdevname(rdev0->bdev,b));
5485 			mddev_unlock(mddev);
5486 		} else {
5487 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
5488 			mddev->persistent = 1;
5489 			rdev_for_each_list(rdev, tmp, &candidates) {
5490 				list_del_init(&rdev->same_set);
5491 				if (bind_rdev_to_array(rdev, mddev))
5492 					export_rdev(rdev);
5493 			}
5494 			autorun_array(mddev);
5495 			mddev_unlock(mddev);
5496 		}
5497 		/* on success, candidates will be empty, on error
5498 		 * it won't...
5499 		 */
5500 		rdev_for_each_list(rdev, tmp, &candidates) {
5501 			list_del_init(&rdev->same_set);
5502 			export_rdev(rdev);
5503 		}
5504 		mddev_put(mddev);
5505 	}
5506 	printk(KERN_INFO "md: ... autorun DONE.\n");
5507 }
5508 #endif /* !MODULE */
5509 
5510 static int get_version(void __user * arg)
5511 {
5512 	mdu_version_t ver;
5513 
5514 	ver.major = MD_MAJOR_VERSION;
5515 	ver.minor = MD_MINOR_VERSION;
5516 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
5517 
5518 	if (copy_to_user(arg, &ver, sizeof(ver)))
5519 		return -EFAULT;
5520 
5521 	return 0;
5522 }
5523 
5524 static int get_array_info(struct mddev * mddev, void __user * arg)
5525 {
5526 	mdu_array_info_t info;
5527 	int nr,working,insync,failed,spare;
5528 	struct md_rdev *rdev;
5529 
5530 	nr=working=insync=failed=spare=0;
5531 	rdev_for_each(rdev, mddev) {
5532 		nr++;
5533 		if (test_bit(Faulty, &rdev->flags))
5534 			failed++;
5535 		else {
5536 			working++;
5537 			if (test_bit(In_sync, &rdev->flags))
5538 				insync++;
5539 			else
5540 				spare++;
5541 		}
5542 	}
5543 
5544 	info.major_version = mddev->major_version;
5545 	info.minor_version = mddev->minor_version;
5546 	info.patch_version = MD_PATCHLEVEL_VERSION;
5547 	info.ctime         = mddev->ctime;
5548 	info.level         = mddev->level;
5549 	info.size          = mddev->dev_sectors / 2;
5550 	if (info.size != mddev->dev_sectors / 2) /* overflow */
5551 		info.size = -1;
5552 	info.nr_disks      = nr;
5553 	info.raid_disks    = mddev->raid_disks;
5554 	info.md_minor      = mddev->md_minor;
5555 	info.not_persistent= !mddev->persistent;
5556 
5557 	info.utime         = mddev->utime;
5558 	info.state         = 0;
5559 	if (mddev->in_sync)
5560 		info.state = (1<<MD_SB_CLEAN);
5561 	if (mddev->bitmap && mddev->bitmap_info.offset)
5562 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5563 	info.active_disks  = insync;
5564 	info.working_disks = working;
5565 	info.failed_disks  = failed;
5566 	info.spare_disks   = spare;
5567 
5568 	info.layout        = mddev->layout;
5569 	info.chunk_size    = mddev->chunk_sectors << 9;
5570 
5571 	if (copy_to_user(arg, &info, sizeof(info)))
5572 		return -EFAULT;
5573 
5574 	return 0;
5575 }
5576 
5577 static int get_bitmap_file(struct mddev * mddev, void __user * arg)
5578 {
5579 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5580 	char *ptr, *buf = NULL;
5581 	int err = -ENOMEM;
5582 
5583 	if (md_allow_write(mddev))
5584 		file = kmalloc(sizeof(*file), GFP_NOIO);
5585 	else
5586 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5587 
5588 	if (!file)
5589 		goto out;
5590 
5591 	/* bitmap disabled, zero the first byte and copy out */
5592 	if (!mddev->bitmap || !mddev->bitmap->storage.file) {
5593 		file->pathname[0] = '\0';
5594 		goto copy_out;
5595 	}
5596 
5597 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5598 	if (!buf)
5599 		goto out;
5600 
5601 	ptr = d_path(&mddev->bitmap->storage.file->f_path,
5602 		     buf, sizeof(file->pathname));
5603 	if (IS_ERR(ptr))
5604 		goto out;
5605 
5606 	strcpy(file->pathname, ptr);
5607 
5608 copy_out:
5609 	err = 0;
5610 	if (copy_to_user(arg, file, sizeof(*file)))
5611 		err = -EFAULT;
5612 out:
5613 	kfree(buf);
5614 	kfree(file);
5615 	return err;
5616 }
5617 
5618 static int get_disk_info(struct mddev * mddev, void __user * arg)
5619 {
5620 	mdu_disk_info_t info;
5621 	struct md_rdev *rdev;
5622 
5623 	if (copy_from_user(&info, arg, sizeof(info)))
5624 		return -EFAULT;
5625 
5626 	rdev = find_rdev_nr(mddev, info.number);
5627 	if (rdev) {
5628 		info.major = MAJOR(rdev->bdev->bd_dev);
5629 		info.minor = MINOR(rdev->bdev->bd_dev);
5630 		info.raid_disk = rdev->raid_disk;
5631 		info.state = 0;
5632 		if (test_bit(Faulty, &rdev->flags))
5633 			info.state |= (1<<MD_DISK_FAULTY);
5634 		else if (test_bit(In_sync, &rdev->flags)) {
5635 			info.state |= (1<<MD_DISK_ACTIVE);
5636 			info.state |= (1<<MD_DISK_SYNC);
5637 		}
5638 		if (test_bit(WriteMostly, &rdev->flags))
5639 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5640 	} else {
5641 		info.major = info.minor = 0;
5642 		info.raid_disk = -1;
5643 		info.state = (1<<MD_DISK_REMOVED);
5644 	}
5645 
5646 	if (copy_to_user(arg, &info, sizeof(info)))
5647 		return -EFAULT;
5648 
5649 	return 0;
5650 }
5651 
5652 static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info)
5653 {
5654 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5655 	struct md_rdev *rdev;
5656 	dev_t dev = MKDEV(info->major,info->minor);
5657 
5658 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5659 		return -EOVERFLOW;
5660 
5661 	if (!mddev->raid_disks) {
5662 		int err;
5663 		/* expecting a device which has a superblock */
5664 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5665 		if (IS_ERR(rdev)) {
5666 			printk(KERN_WARNING
5667 				"md: md_import_device returned %ld\n",
5668 				PTR_ERR(rdev));
5669 			return PTR_ERR(rdev);
5670 		}
5671 		if (!list_empty(&mddev->disks)) {
5672 			struct md_rdev *rdev0
5673 				= list_entry(mddev->disks.next,
5674 					     struct md_rdev, same_set);
5675 			err = super_types[mddev->major_version]
5676 				.load_super(rdev, rdev0, mddev->minor_version);
5677 			if (err < 0) {
5678 				printk(KERN_WARNING
5679 					"md: %s has different UUID to %s\n",
5680 					bdevname(rdev->bdev,b),
5681 					bdevname(rdev0->bdev,b2));
5682 				export_rdev(rdev);
5683 				return -EINVAL;
5684 			}
5685 		}
5686 		err = bind_rdev_to_array(rdev, mddev);
5687 		if (err)
5688 			export_rdev(rdev);
5689 		return err;
5690 	}
5691 
5692 	/*
5693 	 * add_new_disk can be used once the array is assembled
5694 	 * to add "hot spares".  They must already have a superblock
5695 	 * written
5696 	 */
5697 	if (mddev->pers) {
5698 		int err;
5699 		if (!mddev->pers->hot_add_disk) {
5700 			printk(KERN_WARNING
5701 				"%s: personality does not support diskops!\n",
5702 			       mdname(mddev));
5703 			return -EINVAL;
5704 		}
5705 		if (mddev->persistent)
5706 			rdev = md_import_device(dev, mddev->major_version,
5707 						mddev->minor_version);
5708 		else
5709 			rdev = md_import_device(dev, -1, -1);
5710 		if (IS_ERR(rdev)) {
5711 			printk(KERN_WARNING
5712 				"md: md_import_device returned %ld\n",
5713 				PTR_ERR(rdev));
5714 			return PTR_ERR(rdev);
5715 		}
5716 		/* set saved_raid_disk if appropriate */
5717 		if (!mddev->persistent) {
5718 			if (info->state & (1<<MD_DISK_SYNC)  &&
5719 			    info->raid_disk < mddev->raid_disks) {
5720 				rdev->raid_disk = info->raid_disk;
5721 				set_bit(In_sync, &rdev->flags);
5722 			} else
5723 				rdev->raid_disk = -1;
5724 		} else
5725 			super_types[mddev->major_version].
5726 				validate_super(mddev, rdev);
5727 		if ((info->state & (1<<MD_DISK_SYNC)) &&
5728 		     rdev->raid_disk != info->raid_disk) {
5729 			/* This was a hot-add request, but events doesn't
5730 			 * match, so reject it.
5731 			 */
5732 			export_rdev(rdev);
5733 			return -EINVAL;
5734 		}
5735 
5736 		if (test_bit(In_sync, &rdev->flags))
5737 			rdev->saved_raid_disk = rdev->raid_disk;
5738 		else
5739 			rdev->saved_raid_disk = -1;
5740 
5741 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5742 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5743 			set_bit(WriteMostly, &rdev->flags);
5744 		else
5745 			clear_bit(WriteMostly, &rdev->flags);
5746 
5747 		rdev->raid_disk = -1;
5748 		err = bind_rdev_to_array(rdev, mddev);
5749 		if (!err && !mddev->pers->hot_remove_disk) {
5750 			/* If there is hot_add_disk but no hot_remove_disk
5751 			 * then added disks for geometry changes,
5752 			 * and should be added immediately.
5753 			 */
5754 			super_types[mddev->major_version].
5755 				validate_super(mddev, rdev);
5756 			err = mddev->pers->hot_add_disk(mddev, rdev);
5757 			if (err)
5758 				unbind_rdev_from_array(rdev);
5759 		}
5760 		if (err)
5761 			export_rdev(rdev);
5762 		else
5763 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5764 
5765 		md_update_sb(mddev, 1);
5766 		if (mddev->degraded)
5767 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5768 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5769 		if (!err)
5770 			md_new_event(mddev);
5771 		md_wakeup_thread(mddev->thread);
5772 		return err;
5773 	}
5774 
5775 	/* otherwise, add_new_disk is only allowed
5776 	 * for major_version==0 superblocks
5777 	 */
5778 	if (mddev->major_version != 0) {
5779 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5780 		       mdname(mddev));
5781 		return -EINVAL;
5782 	}
5783 
5784 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5785 		int err;
5786 		rdev = md_import_device(dev, -1, 0);
5787 		if (IS_ERR(rdev)) {
5788 			printk(KERN_WARNING
5789 				"md: error, md_import_device() returned %ld\n",
5790 				PTR_ERR(rdev));
5791 			return PTR_ERR(rdev);
5792 		}
5793 		rdev->desc_nr = info->number;
5794 		if (info->raid_disk < mddev->raid_disks)
5795 			rdev->raid_disk = info->raid_disk;
5796 		else
5797 			rdev->raid_disk = -1;
5798 
5799 		if (rdev->raid_disk < mddev->raid_disks)
5800 			if (info->state & (1<<MD_DISK_SYNC))
5801 				set_bit(In_sync, &rdev->flags);
5802 
5803 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5804 			set_bit(WriteMostly, &rdev->flags);
5805 
5806 		if (!mddev->persistent) {
5807 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5808 			rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5809 		} else
5810 			rdev->sb_start = calc_dev_sboffset(rdev);
5811 		rdev->sectors = rdev->sb_start;
5812 
5813 		err = bind_rdev_to_array(rdev, mddev);
5814 		if (err) {
5815 			export_rdev(rdev);
5816 			return err;
5817 		}
5818 	}
5819 
5820 	return 0;
5821 }
5822 
5823 static int hot_remove_disk(struct mddev * mddev, dev_t dev)
5824 {
5825 	char b[BDEVNAME_SIZE];
5826 	struct md_rdev *rdev;
5827 
5828 	rdev = find_rdev(mddev, dev);
5829 	if (!rdev)
5830 		return -ENXIO;
5831 
5832 	if (rdev->raid_disk >= 0)
5833 		goto busy;
5834 
5835 	kick_rdev_from_array(rdev);
5836 	md_update_sb(mddev, 1);
5837 	md_new_event(mddev);
5838 
5839 	return 0;
5840 busy:
5841 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5842 		bdevname(rdev->bdev,b), mdname(mddev));
5843 	return -EBUSY;
5844 }
5845 
5846 static int hot_add_disk(struct mddev * mddev, dev_t dev)
5847 {
5848 	char b[BDEVNAME_SIZE];
5849 	int err;
5850 	struct md_rdev *rdev;
5851 
5852 	if (!mddev->pers)
5853 		return -ENODEV;
5854 
5855 	if (mddev->major_version != 0) {
5856 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5857 			" version-0 superblocks.\n",
5858 			mdname(mddev));
5859 		return -EINVAL;
5860 	}
5861 	if (!mddev->pers->hot_add_disk) {
5862 		printk(KERN_WARNING
5863 			"%s: personality does not support diskops!\n",
5864 			mdname(mddev));
5865 		return -EINVAL;
5866 	}
5867 
5868 	rdev = md_import_device(dev, -1, 0);
5869 	if (IS_ERR(rdev)) {
5870 		printk(KERN_WARNING
5871 			"md: error, md_import_device() returned %ld\n",
5872 			PTR_ERR(rdev));
5873 		return -EINVAL;
5874 	}
5875 
5876 	if (mddev->persistent)
5877 		rdev->sb_start = calc_dev_sboffset(rdev);
5878 	else
5879 		rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5880 
5881 	rdev->sectors = rdev->sb_start;
5882 
5883 	if (test_bit(Faulty, &rdev->flags)) {
5884 		printk(KERN_WARNING
5885 			"md: can not hot-add faulty %s disk to %s!\n",
5886 			bdevname(rdev->bdev,b), mdname(mddev));
5887 		err = -EINVAL;
5888 		goto abort_export;
5889 	}
5890 	clear_bit(In_sync, &rdev->flags);
5891 	rdev->desc_nr = -1;
5892 	rdev->saved_raid_disk = -1;
5893 	err = bind_rdev_to_array(rdev, mddev);
5894 	if (err)
5895 		goto abort_export;
5896 
5897 	/*
5898 	 * The rest should better be atomic, we can have disk failures
5899 	 * noticed in interrupt contexts ...
5900 	 */
5901 
5902 	rdev->raid_disk = -1;
5903 
5904 	md_update_sb(mddev, 1);
5905 
5906 	/*
5907 	 * Kick recovery, maybe this spare has to be added to the
5908 	 * array immediately.
5909 	 */
5910 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5911 	md_wakeup_thread(mddev->thread);
5912 	md_new_event(mddev);
5913 	return 0;
5914 
5915 abort_export:
5916 	export_rdev(rdev);
5917 	return err;
5918 }
5919 
5920 static int set_bitmap_file(struct mddev *mddev, int fd)
5921 {
5922 	int err;
5923 
5924 	if (mddev->pers) {
5925 		if (!mddev->pers->quiesce)
5926 			return -EBUSY;
5927 		if (mddev->recovery || mddev->sync_thread)
5928 			return -EBUSY;
5929 		/* we should be able to change the bitmap.. */
5930 	}
5931 
5932 
5933 	if (fd >= 0) {
5934 		if (mddev->bitmap)
5935 			return -EEXIST; /* cannot add when bitmap is present */
5936 		mddev->bitmap_info.file = fget(fd);
5937 
5938 		if (mddev->bitmap_info.file == NULL) {
5939 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5940 			       mdname(mddev));
5941 			return -EBADF;
5942 		}
5943 
5944 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5945 		if (err) {
5946 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5947 			       mdname(mddev));
5948 			fput(mddev->bitmap_info.file);
5949 			mddev->bitmap_info.file = NULL;
5950 			return err;
5951 		}
5952 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5953 	} else if (mddev->bitmap == NULL)
5954 		return -ENOENT; /* cannot remove what isn't there */
5955 	err = 0;
5956 	if (mddev->pers) {
5957 		mddev->pers->quiesce(mddev, 1);
5958 		if (fd >= 0) {
5959 			err = bitmap_create(mddev);
5960 			if (!err)
5961 				err = bitmap_load(mddev);
5962 		}
5963 		if (fd < 0 || err) {
5964 			bitmap_destroy(mddev);
5965 			fd = -1; /* make sure to put the file */
5966 		}
5967 		mddev->pers->quiesce(mddev, 0);
5968 	}
5969 	if (fd < 0) {
5970 		if (mddev->bitmap_info.file) {
5971 			restore_bitmap_write_access(mddev->bitmap_info.file);
5972 			fput(mddev->bitmap_info.file);
5973 		}
5974 		mddev->bitmap_info.file = NULL;
5975 	}
5976 
5977 	return err;
5978 }
5979 
5980 /*
5981  * set_array_info is used two different ways
5982  * The original usage is when creating a new array.
5983  * In this usage, raid_disks is > 0 and it together with
5984  *  level, size, not_persistent,layout,chunksize determine the
5985  *  shape of the array.
5986  *  This will always create an array with a type-0.90.0 superblock.
5987  * The newer usage is when assembling an array.
5988  *  In this case raid_disks will be 0, and the major_version field is
5989  *  use to determine which style super-blocks are to be found on the devices.
5990  *  The minor and patch _version numbers are also kept incase the
5991  *  super_block handler wishes to interpret them.
5992  */
5993 static int set_array_info(struct mddev * mddev, mdu_array_info_t *info)
5994 {
5995 
5996 	if (info->raid_disks == 0) {
5997 		/* just setting version number for superblock loading */
5998 		if (info->major_version < 0 ||
5999 		    info->major_version >= ARRAY_SIZE(super_types) ||
6000 		    super_types[info->major_version].name == NULL) {
6001 			/* maybe try to auto-load a module? */
6002 			printk(KERN_INFO
6003 				"md: superblock version %d not known\n",
6004 				info->major_version);
6005 			return -EINVAL;
6006 		}
6007 		mddev->major_version = info->major_version;
6008 		mddev->minor_version = info->minor_version;
6009 		mddev->patch_version = info->patch_version;
6010 		mddev->persistent = !info->not_persistent;
6011 		/* ensure mddev_put doesn't delete this now that there
6012 		 * is some minimal configuration.
6013 		 */
6014 		mddev->ctime         = get_seconds();
6015 		return 0;
6016 	}
6017 	mddev->major_version = MD_MAJOR_VERSION;
6018 	mddev->minor_version = MD_MINOR_VERSION;
6019 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
6020 	mddev->ctime         = get_seconds();
6021 
6022 	mddev->level         = info->level;
6023 	mddev->clevel[0]     = 0;
6024 	mddev->dev_sectors   = 2 * (sector_t)info->size;
6025 	mddev->raid_disks    = info->raid_disks;
6026 	/* don't set md_minor, it is determined by which /dev/md* was
6027 	 * openned
6028 	 */
6029 	if (info->state & (1<<MD_SB_CLEAN))
6030 		mddev->recovery_cp = MaxSector;
6031 	else
6032 		mddev->recovery_cp = 0;
6033 	mddev->persistent    = ! info->not_persistent;
6034 	mddev->external	     = 0;
6035 
6036 	mddev->layout        = info->layout;
6037 	mddev->chunk_sectors = info->chunk_size >> 9;
6038 
6039 	mddev->max_disks     = MD_SB_DISKS;
6040 
6041 	if (mddev->persistent)
6042 		mddev->flags         = 0;
6043 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6044 
6045 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6046 	mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6047 	mddev->bitmap_info.offset = 0;
6048 
6049 	mddev->reshape_position = MaxSector;
6050 
6051 	/*
6052 	 * Generate a 128 bit UUID
6053 	 */
6054 	get_random_bytes(mddev->uuid, 16);
6055 
6056 	mddev->new_level = mddev->level;
6057 	mddev->new_chunk_sectors = mddev->chunk_sectors;
6058 	mddev->new_layout = mddev->layout;
6059 	mddev->delta_disks = 0;
6060 	mddev->reshape_backwards = 0;
6061 
6062 	return 0;
6063 }
6064 
6065 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6066 {
6067 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6068 
6069 	if (mddev->external_size)
6070 		return;
6071 
6072 	mddev->array_sectors = array_sectors;
6073 }
6074 EXPORT_SYMBOL(md_set_array_sectors);
6075 
6076 static int update_size(struct mddev *mddev, sector_t num_sectors)
6077 {
6078 	struct md_rdev *rdev;
6079 	int rv;
6080 	int fit = (num_sectors == 0);
6081 
6082 	if (mddev->pers->resize == NULL)
6083 		return -EINVAL;
6084 	/* The "num_sectors" is the number of sectors of each device that
6085 	 * is used.  This can only make sense for arrays with redundancy.
6086 	 * linear and raid0 always use whatever space is available. We can only
6087 	 * consider changing this number if no resync or reconstruction is
6088 	 * happening, and if the new size is acceptable. It must fit before the
6089 	 * sb_start or, if that is <data_offset, it must fit before the size
6090 	 * of each device.  If num_sectors is zero, we find the largest size
6091 	 * that fits.
6092 	 */
6093 	if (mddev->sync_thread)
6094 		return -EBUSY;
6095 
6096 	rdev_for_each(rdev, mddev) {
6097 		sector_t avail = rdev->sectors;
6098 
6099 		if (fit && (num_sectors == 0 || num_sectors > avail))
6100 			num_sectors = avail;
6101 		if (avail < num_sectors)
6102 			return -ENOSPC;
6103 	}
6104 	rv = mddev->pers->resize(mddev, num_sectors);
6105 	if (!rv)
6106 		revalidate_disk(mddev->gendisk);
6107 	return rv;
6108 }
6109 
6110 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6111 {
6112 	int rv;
6113 	struct md_rdev *rdev;
6114 	/* change the number of raid disks */
6115 	if (mddev->pers->check_reshape == NULL)
6116 		return -EINVAL;
6117 	if (raid_disks <= 0 ||
6118 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
6119 		return -EINVAL;
6120 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
6121 		return -EBUSY;
6122 
6123 	rdev_for_each(rdev, mddev) {
6124 		if (mddev->raid_disks < raid_disks &&
6125 		    rdev->data_offset < rdev->new_data_offset)
6126 			return -EINVAL;
6127 		if (mddev->raid_disks > raid_disks &&
6128 		    rdev->data_offset > rdev->new_data_offset)
6129 			return -EINVAL;
6130 	}
6131 
6132 	mddev->delta_disks = raid_disks - mddev->raid_disks;
6133 	if (mddev->delta_disks < 0)
6134 		mddev->reshape_backwards = 1;
6135 	else if (mddev->delta_disks > 0)
6136 		mddev->reshape_backwards = 0;
6137 
6138 	rv = mddev->pers->check_reshape(mddev);
6139 	if (rv < 0) {
6140 		mddev->delta_disks = 0;
6141 		mddev->reshape_backwards = 0;
6142 	}
6143 	return rv;
6144 }
6145 
6146 
6147 /*
6148  * update_array_info is used to change the configuration of an
6149  * on-line array.
6150  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6151  * fields in the info are checked against the array.
6152  * Any differences that cannot be handled will cause an error.
6153  * Normally, only one change can be managed at a time.
6154  */
6155 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6156 {
6157 	int rv = 0;
6158 	int cnt = 0;
6159 	int state = 0;
6160 
6161 	/* calculate expected state,ignoring low bits */
6162 	if (mddev->bitmap && mddev->bitmap_info.offset)
6163 		state |= (1 << MD_SB_BITMAP_PRESENT);
6164 
6165 	if (mddev->major_version != info->major_version ||
6166 	    mddev->minor_version != info->minor_version ||
6167 /*	    mddev->patch_version != info->patch_version || */
6168 	    mddev->ctime         != info->ctime         ||
6169 	    mddev->level         != info->level         ||
6170 /*	    mddev->layout        != info->layout        || */
6171 	    !mddev->persistent	 != info->not_persistent||
6172 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
6173 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6174 	    ((state^info->state) & 0xfffffe00)
6175 		)
6176 		return -EINVAL;
6177 	/* Check there is only one change */
6178 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6179 		cnt++;
6180 	if (mddev->raid_disks != info->raid_disks)
6181 		cnt++;
6182 	if (mddev->layout != info->layout)
6183 		cnt++;
6184 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6185 		cnt++;
6186 	if (cnt == 0)
6187 		return 0;
6188 	if (cnt > 1)
6189 		return -EINVAL;
6190 
6191 	if (mddev->layout != info->layout) {
6192 		/* Change layout
6193 		 * we don't need to do anything at the md level, the
6194 		 * personality will take care of it all.
6195 		 */
6196 		if (mddev->pers->check_reshape == NULL)
6197 			return -EINVAL;
6198 		else {
6199 			mddev->new_layout = info->layout;
6200 			rv = mddev->pers->check_reshape(mddev);
6201 			if (rv)
6202 				mddev->new_layout = mddev->layout;
6203 			return rv;
6204 		}
6205 	}
6206 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6207 		rv = update_size(mddev, (sector_t)info->size * 2);
6208 
6209 	if (mddev->raid_disks    != info->raid_disks)
6210 		rv = update_raid_disks(mddev, info->raid_disks);
6211 
6212 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6213 		if (mddev->pers->quiesce == NULL)
6214 			return -EINVAL;
6215 		if (mddev->recovery || mddev->sync_thread)
6216 			return -EBUSY;
6217 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6218 			/* add the bitmap */
6219 			if (mddev->bitmap)
6220 				return -EEXIST;
6221 			if (mddev->bitmap_info.default_offset == 0)
6222 				return -EINVAL;
6223 			mddev->bitmap_info.offset =
6224 				mddev->bitmap_info.default_offset;
6225 			mddev->bitmap_info.space =
6226 				mddev->bitmap_info.default_space;
6227 			mddev->pers->quiesce(mddev, 1);
6228 			rv = bitmap_create(mddev);
6229 			if (!rv)
6230 				rv = bitmap_load(mddev);
6231 			if (rv)
6232 				bitmap_destroy(mddev);
6233 			mddev->pers->quiesce(mddev, 0);
6234 		} else {
6235 			/* remove the bitmap */
6236 			if (!mddev->bitmap)
6237 				return -ENOENT;
6238 			if (mddev->bitmap->storage.file)
6239 				return -EINVAL;
6240 			mddev->pers->quiesce(mddev, 1);
6241 			bitmap_destroy(mddev);
6242 			mddev->pers->quiesce(mddev, 0);
6243 			mddev->bitmap_info.offset = 0;
6244 		}
6245 	}
6246 	md_update_sb(mddev, 1);
6247 	return rv;
6248 }
6249 
6250 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6251 {
6252 	struct md_rdev *rdev;
6253 
6254 	if (mddev->pers == NULL)
6255 		return -ENODEV;
6256 
6257 	rdev = find_rdev(mddev, dev);
6258 	if (!rdev)
6259 		return -ENODEV;
6260 
6261 	md_error(mddev, rdev);
6262 	if (!test_bit(Faulty, &rdev->flags))
6263 		return -EBUSY;
6264 	return 0;
6265 }
6266 
6267 /*
6268  * We have a problem here : there is no easy way to give a CHS
6269  * virtual geometry. We currently pretend that we have a 2 heads
6270  * 4 sectors (with a BIG number of cylinders...). This drives
6271  * dosfs just mad... ;-)
6272  */
6273 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6274 {
6275 	struct mddev *mddev = bdev->bd_disk->private_data;
6276 
6277 	geo->heads = 2;
6278 	geo->sectors = 4;
6279 	geo->cylinders = mddev->array_sectors / 8;
6280 	return 0;
6281 }
6282 
6283 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6284 			unsigned int cmd, unsigned long arg)
6285 {
6286 	int err = 0;
6287 	void __user *argp = (void __user *)arg;
6288 	struct mddev *mddev = NULL;
6289 	int ro;
6290 
6291 	switch (cmd) {
6292 	case RAID_VERSION:
6293 	case GET_ARRAY_INFO:
6294 	case GET_DISK_INFO:
6295 		break;
6296 	default:
6297 		if (!capable(CAP_SYS_ADMIN))
6298 			return -EACCES;
6299 	}
6300 
6301 	/*
6302 	 * Commands dealing with the RAID driver but not any
6303 	 * particular array:
6304 	 */
6305 	switch (cmd)
6306 	{
6307 		case RAID_VERSION:
6308 			err = get_version(argp);
6309 			goto done;
6310 
6311 		case PRINT_RAID_DEBUG:
6312 			err = 0;
6313 			md_print_devices();
6314 			goto done;
6315 
6316 #ifndef MODULE
6317 		case RAID_AUTORUN:
6318 			err = 0;
6319 			autostart_arrays(arg);
6320 			goto done;
6321 #endif
6322 		default:;
6323 	}
6324 
6325 	/*
6326 	 * Commands creating/starting a new array:
6327 	 */
6328 
6329 	mddev = bdev->bd_disk->private_data;
6330 
6331 	if (!mddev) {
6332 		BUG();
6333 		goto abort;
6334 	}
6335 
6336 	err = mddev_lock(mddev);
6337 	if (err) {
6338 		printk(KERN_INFO
6339 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
6340 			err, cmd);
6341 		goto abort;
6342 	}
6343 
6344 	switch (cmd)
6345 	{
6346 		case SET_ARRAY_INFO:
6347 			{
6348 				mdu_array_info_t info;
6349 				if (!arg)
6350 					memset(&info, 0, sizeof(info));
6351 				else if (copy_from_user(&info, argp, sizeof(info))) {
6352 					err = -EFAULT;
6353 					goto abort_unlock;
6354 				}
6355 				if (mddev->pers) {
6356 					err = update_array_info(mddev, &info);
6357 					if (err) {
6358 						printk(KERN_WARNING "md: couldn't update"
6359 						       " array info. %d\n", err);
6360 						goto abort_unlock;
6361 					}
6362 					goto done_unlock;
6363 				}
6364 				if (!list_empty(&mddev->disks)) {
6365 					printk(KERN_WARNING
6366 					       "md: array %s already has disks!\n",
6367 					       mdname(mddev));
6368 					err = -EBUSY;
6369 					goto abort_unlock;
6370 				}
6371 				if (mddev->raid_disks) {
6372 					printk(KERN_WARNING
6373 					       "md: array %s already initialised!\n",
6374 					       mdname(mddev));
6375 					err = -EBUSY;
6376 					goto abort_unlock;
6377 				}
6378 				err = set_array_info(mddev, &info);
6379 				if (err) {
6380 					printk(KERN_WARNING "md: couldn't set"
6381 					       " array info. %d\n", err);
6382 					goto abort_unlock;
6383 				}
6384 			}
6385 			goto done_unlock;
6386 
6387 		default:;
6388 	}
6389 
6390 	/*
6391 	 * Commands querying/configuring an existing array:
6392 	 */
6393 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6394 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6395 	if ((!mddev->raid_disks && !mddev->external)
6396 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6397 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6398 	    && cmd != GET_BITMAP_FILE) {
6399 		err = -ENODEV;
6400 		goto abort_unlock;
6401 	}
6402 
6403 	/*
6404 	 * Commands even a read-only array can execute:
6405 	 */
6406 	switch (cmd)
6407 	{
6408 		case GET_ARRAY_INFO:
6409 			err = get_array_info(mddev, argp);
6410 			goto done_unlock;
6411 
6412 		case GET_BITMAP_FILE:
6413 			err = get_bitmap_file(mddev, argp);
6414 			goto done_unlock;
6415 
6416 		case GET_DISK_INFO:
6417 			err = get_disk_info(mddev, argp);
6418 			goto done_unlock;
6419 
6420 		case RESTART_ARRAY_RW:
6421 			err = restart_array(mddev);
6422 			goto done_unlock;
6423 
6424 		case STOP_ARRAY:
6425 			err = do_md_stop(mddev, 0, bdev);
6426 			goto done_unlock;
6427 
6428 		case STOP_ARRAY_RO:
6429 			err = md_set_readonly(mddev, bdev);
6430 			goto done_unlock;
6431 
6432 		case BLKROSET:
6433 			if (get_user(ro, (int __user *)(arg))) {
6434 				err = -EFAULT;
6435 				goto done_unlock;
6436 			}
6437 			err = -EINVAL;
6438 
6439 			/* if the bdev is going readonly the value of mddev->ro
6440 			 * does not matter, no writes are coming
6441 			 */
6442 			if (ro)
6443 				goto done_unlock;
6444 
6445 			/* are we are already prepared for writes? */
6446 			if (mddev->ro != 1)
6447 				goto done_unlock;
6448 
6449 			/* transitioning to readauto need only happen for
6450 			 * arrays that call md_write_start
6451 			 */
6452 			if (mddev->pers) {
6453 				err = restart_array(mddev);
6454 				if (err == 0) {
6455 					mddev->ro = 2;
6456 					set_disk_ro(mddev->gendisk, 0);
6457 				}
6458 			}
6459 			goto done_unlock;
6460 	}
6461 
6462 	/*
6463 	 * The remaining ioctls are changing the state of the
6464 	 * superblock, so we do not allow them on read-only arrays.
6465 	 * However non-MD ioctls (e.g. get-size) will still come through
6466 	 * here and hit the 'default' below, so only disallow
6467 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
6468 	 */
6469 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6470 		if (mddev->ro == 2) {
6471 			mddev->ro = 0;
6472 			sysfs_notify_dirent_safe(mddev->sysfs_state);
6473 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6474 			md_wakeup_thread(mddev->thread);
6475 		} else {
6476 			err = -EROFS;
6477 			goto abort_unlock;
6478 		}
6479 	}
6480 
6481 	switch (cmd)
6482 	{
6483 		case ADD_NEW_DISK:
6484 		{
6485 			mdu_disk_info_t info;
6486 			if (copy_from_user(&info, argp, sizeof(info)))
6487 				err = -EFAULT;
6488 			else
6489 				err = add_new_disk(mddev, &info);
6490 			goto done_unlock;
6491 		}
6492 
6493 		case HOT_REMOVE_DISK:
6494 			err = hot_remove_disk(mddev, new_decode_dev(arg));
6495 			goto done_unlock;
6496 
6497 		case HOT_ADD_DISK:
6498 			err = hot_add_disk(mddev, new_decode_dev(arg));
6499 			goto done_unlock;
6500 
6501 		case SET_DISK_FAULTY:
6502 			err = set_disk_faulty(mddev, new_decode_dev(arg));
6503 			goto done_unlock;
6504 
6505 		case RUN_ARRAY:
6506 			err = do_md_run(mddev);
6507 			goto done_unlock;
6508 
6509 		case SET_BITMAP_FILE:
6510 			err = set_bitmap_file(mddev, (int)arg);
6511 			goto done_unlock;
6512 
6513 		default:
6514 			err = -EINVAL;
6515 			goto abort_unlock;
6516 	}
6517 
6518 done_unlock:
6519 abort_unlock:
6520 	if (mddev->hold_active == UNTIL_IOCTL &&
6521 	    err != -EINVAL)
6522 		mddev->hold_active = 0;
6523 	mddev_unlock(mddev);
6524 
6525 	return err;
6526 done:
6527 	if (err)
6528 		MD_BUG();
6529 abort:
6530 	return err;
6531 }
6532 #ifdef CONFIG_COMPAT
6533 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6534 		    unsigned int cmd, unsigned long arg)
6535 {
6536 	switch (cmd) {
6537 	case HOT_REMOVE_DISK:
6538 	case HOT_ADD_DISK:
6539 	case SET_DISK_FAULTY:
6540 	case SET_BITMAP_FILE:
6541 		/* These take in integer arg, do not convert */
6542 		break;
6543 	default:
6544 		arg = (unsigned long)compat_ptr(arg);
6545 		break;
6546 	}
6547 
6548 	return md_ioctl(bdev, mode, cmd, arg);
6549 }
6550 #endif /* CONFIG_COMPAT */
6551 
6552 static int md_open(struct block_device *bdev, fmode_t mode)
6553 {
6554 	/*
6555 	 * Succeed if we can lock the mddev, which confirms that
6556 	 * it isn't being stopped right now.
6557 	 */
6558 	struct mddev *mddev = mddev_find(bdev->bd_dev);
6559 	int err;
6560 
6561 	if (!mddev)
6562 		return -ENODEV;
6563 
6564 	if (mddev->gendisk != bdev->bd_disk) {
6565 		/* we are racing with mddev_put which is discarding this
6566 		 * bd_disk.
6567 		 */
6568 		mddev_put(mddev);
6569 		/* Wait until bdev->bd_disk is definitely gone */
6570 		flush_workqueue(md_misc_wq);
6571 		/* Then retry the open from the top */
6572 		return -ERESTARTSYS;
6573 	}
6574 	BUG_ON(mddev != bdev->bd_disk->private_data);
6575 
6576 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6577 		goto out;
6578 
6579 	err = 0;
6580 	atomic_inc(&mddev->openers);
6581 	mutex_unlock(&mddev->open_mutex);
6582 
6583 	check_disk_change(bdev);
6584  out:
6585 	return err;
6586 }
6587 
6588 static int md_release(struct gendisk *disk, fmode_t mode)
6589 {
6590  	struct mddev *mddev = disk->private_data;
6591 
6592 	BUG_ON(!mddev);
6593 	atomic_dec(&mddev->openers);
6594 	mddev_put(mddev);
6595 
6596 	return 0;
6597 }
6598 
6599 static int md_media_changed(struct gendisk *disk)
6600 {
6601 	struct mddev *mddev = disk->private_data;
6602 
6603 	return mddev->changed;
6604 }
6605 
6606 static int md_revalidate(struct gendisk *disk)
6607 {
6608 	struct mddev *mddev = disk->private_data;
6609 
6610 	mddev->changed = 0;
6611 	return 0;
6612 }
6613 static const struct block_device_operations md_fops =
6614 {
6615 	.owner		= THIS_MODULE,
6616 	.open		= md_open,
6617 	.release	= md_release,
6618 	.ioctl		= md_ioctl,
6619 #ifdef CONFIG_COMPAT
6620 	.compat_ioctl	= md_compat_ioctl,
6621 #endif
6622 	.getgeo		= md_getgeo,
6623 	.media_changed  = md_media_changed,
6624 	.revalidate_disk= md_revalidate,
6625 };
6626 
6627 static int md_thread(void * arg)
6628 {
6629 	struct md_thread *thread = arg;
6630 
6631 	/*
6632 	 * md_thread is a 'system-thread', it's priority should be very
6633 	 * high. We avoid resource deadlocks individually in each
6634 	 * raid personality. (RAID5 does preallocation) We also use RR and
6635 	 * the very same RT priority as kswapd, thus we will never get
6636 	 * into a priority inversion deadlock.
6637 	 *
6638 	 * we definitely have to have equal or higher priority than
6639 	 * bdflush, otherwise bdflush will deadlock if there are too
6640 	 * many dirty RAID5 blocks.
6641 	 */
6642 
6643 	allow_signal(SIGKILL);
6644 	while (!kthread_should_stop()) {
6645 
6646 		/* We need to wait INTERRUPTIBLE so that
6647 		 * we don't add to the load-average.
6648 		 * That means we need to be sure no signals are
6649 		 * pending
6650 		 */
6651 		if (signal_pending(current))
6652 			flush_signals(current);
6653 
6654 		wait_event_interruptible_timeout
6655 			(thread->wqueue,
6656 			 test_bit(THREAD_WAKEUP, &thread->flags)
6657 			 || kthread_should_stop(),
6658 			 thread->timeout);
6659 
6660 		clear_bit(THREAD_WAKEUP, &thread->flags);
6661 		if (!kthread_should_stop())
6662 			thread->run(thread->mddev);
6663 	}
6664 
6665 	return 0;
6666 }
6667 
6668 void md_wakeup_thread(struct md_thread *thread)
6669 {
6670 	if (thread) {
6671 		pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
6672 		set_bit(THREAD_WAKEUP, &thread->flags);
6673 		wake_up(&thread->wqueue);
6674 	}
6675 }
6676 
6677 struct md_thread *md_register_thread(void (*run) (struct mddev *), struct mddev *mddev,
6678 				 const char *name)
6679 {
6680 	struct md_thread *thread;
6681 
6682 	thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
6683 	if (!thread)
6684 		return NULL;
6685 
6686 	init_waitqueue_head(&thread->wqueue);
6687 
6688 	thread->run = run;
6689 	thread->mddev = mddev;
6690 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6691 	thread->tsk = kthread_run(md_thread, thread,
6692 				  "%s_%s",
6693 				  mdname(thread->mddev),
6694 				  name);
6695 	if (IS_ERR(thread->tsk)) {
6696 		kfree(thread);
6697 		return NULL;
6698 	}
6699 	return thread;
6700 }
6701 
6702 void md_unregister_thread(struct md_thread **threadp)
6703 {
6704 	struct md_thread *thread = *threadp;
6705 	if (!thread)
6706 		return;
6707 	pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6708 	/* Locking ensures that mddev_unlock does not wake_up a
6709 	 * non-existent thread
6710 	 */
6711 	spin_lock(&pers_lock);
6712 	*threadp = NULL;
6713 	spin_unlock(&pers_lock);
6714 
6715 	kthread_stop(thread->tsk);
6716 	kfree(thread);
6717 }
6718 
6719 void md_error(struct mddev *mddev, struct md_rdev *rdev)
6720 {
6721 	if (!mddev) {
6722 		MD_BUG();
6723 		return;
6724 	}
6725 
6726 	if (!rdev || test_bit(Faulty, &rdev->flags))
6727 		return;
6728 
6729 	if (!mddev->pers || !mddev->pers->error_handler)
6730 		return;
6731 	mddev->pers->error_handler(mddev,rdev);
6732 	if (mddev->degraded)
6733 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6734 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6735 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6736 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6737 	md_wakeup_thread(mddev->thread);
6738 	if (mddev->event_work.func)
6739 		queue_work(md_misc_wq, &mddev->event_work);
6740 	md_new_event_inintr(mddev);
6741 }
6742 
6743 /* seq_file implementation /proc/mdstat */
6744 
6745 static void status_unused(struct seq_file *seq)
6746 {
6747 	int i = 0;
6748 	struct md_rdev *rdev;
6749 
6750 	seq_printf(seq, "unused devices: ");
6751 
6752 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6753 		char b[BDEVNAME_SIZE];
6754 		i++;
6755 		seq_printf(seq, "%s ",
6756 			      bdevname(rdev->bdev,b));
6757 	}
6758 	if (!i)
6759 		seq_printf(seq, "<none>");
6760 
6761 	seq_printf(seq, "\n");
6762 }
6763 
6764 
6765 static void status_resync(struct seq_file *seq, struct mddev * mddev)
6766 {
6767 	sector_t max_sectors, resync, res;
6768 	unsigned long dt, db;
6769 	sector_t rt;
6770 	int scale;
6771 	unsigned int per_milli;
6772 
6773 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6774 
6775 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
6776 	    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6777 		max_sectors = mddev->resync_max_sectors;
6778 	else
6779 		max_sectors = mddev->dev_sectors;
6780 
6781 	/*
6782 	 * Should not happen.
6783 	 */
6784 	if (!max_sectors) {
6785 		MD_BUG();
6786 		return;
6787 	}
6788 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6789 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6790 	 * u32, as those are the requirements for sector_div.
6791 	 * Thus 'scale' must be at least 10
6792 	 */
6793 	scale = 10;
6794 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6795 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6796 			scale++;
6797 	}
6798 	res = (resync>>scale)*1000;
6799 	sector_div(res, (u32)((max_sectors>>scale)+1));
6800 
6801 	per_milli = res;
6802 	{
6803 		int i, x = per_milli/50, y = 20-x;
6804 		seq_printf(seq, "[");
6805 		for (i = 0; i < x; i++)
6806 			seq_printf(seq, "=");
6807 		seq_printf(seq, ">");
6808 		for (i = 0; i < y; i++)
6809 			seq_printf(seq, ".");
6810 		seq_printf(seq, "] ");
6811 	}
6812 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6813 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6814 		    "reshape" :
6815 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6816 		     "check" :
6817 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6818 		      "resync" : "recovery"))),
6819 		   per_milli/10, per_milli % 10,
6820 		   (unsigned long long) resync/2,
6821 		   (unsigned long long) max_sectors/2);
6822 
6823 	/*
6824 	 * dt: time from mark until now
6825 	 * db: blocks written from mark until now
6826 	 * rt: remaining time
6827 	 *
6828 	 * rt is a sector_t, so could be 32bit or 64bit.
6829 	 * So we divide before multiply in case it is 32bit and close
6830 	 * to the limit.
6831 	 * We scale the divisor (db) by 32 to avoid losing precision
6832 	 * near the end of resync when the number of remaining sectors
6833 	 * is close to 'db'.
6834 	 * We then divide rt by 32 after multiplying by db to compensate.
6835 	 * The '+1' avoids division by zero if db is very small.
6836 	 */
6837 	dt = ((jiffies - mddev->resync_mark) / HZ);
6838 	if (!dt) dt++;
6839 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6840 		- mddev->resync_mark_cnt;
6841 
6842 	rt = max_sectors - resync;    /* number of remaining sectors */
6843 	sector_div(rt, db/32+1);
6844 	rt *= dt;
6845 	rt >>= 5;
6846 
6847 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6848 		   ((unsigned long)rt % 60)/6);
6849 
6850 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6851 }
6852 
6853 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6854 {
6855 	struct list_head *tmp;
6856 	loff_t l = *pos;
6857 	struct mddev *mddev;
6858 
6859 	if (l >= 0x10000)
6860 		return NULL;
6861 	if (!l--)
6862 		/* header */
6863 		return (void*)1;
6864 
6865 	spin_lock(&all_mddevs_lock);
6866 	list_for_each(tmp,&all_mddevs)
6867 		if (!l--) {
6868 			mddev = list_entry(tmp, struct mddev, all_mddevs);
6869 			mddev_get(mddev);
6870 			spin_unlock(&all_mddevs_lock);
6871 			return mddev;
6872 		}
6873 	spin_unlock(&all_mddevs_lock);
6874 	if (!l--)
6875 		return (void*)2;/* tail */
6876 	return NULL;
6877 }
6878 
6879 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6880 {
6881 	struct list_head *tmp;
6882 	struct mddev *next_mddev, *mddev = v;
6883 
6884 	++*pos;
6885 	if (v == (void*)2)
6886 		return NULL;
6887 
6888 	spin_lock(&all_mddevs_lock);
6889 	if (v == (void*)1)
6890 		tmp = all_mddevs.next;
6891 	else
6892 		tmp = mddev->all_mddevs.next;
6893 	if (tmp != &all_mddevs)
6894 		next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
6895 	else {
6896 		next_mddev = (void*)2;
6897 		*pos = 0x10000;
6898 	}
6899 	spin_unlock(&all_mddevs_lock);
6900 
6901 	if (v != (void*)1)
6902 		mddev_put(mddev);
6903 	return next_mddev;
6904 
6905 }
6906 
6907 static void md_seq_stop(struct seq_file *seq, void *v)
6908 {
6909 	struct mddev *mddev = v;
6910 
6911 	if (mddev && v != (void*)1 && v != (void*)2)
6912 		mddev_put(mddev);
6913 }
6914 
6915 static int md_seq_show(struct seq_file *seq, void *v)
6916 {
6917 	struct mddev *mddev = v;
6918 	sector_t sectors;
6919 	struct md_rdev *rdev;
6920 
6921 	if (v == (void*)1) {
6922 		struct md_personality *pers;
6923 		seq_printf(seq, "Personalities : ");
6924 		spin_lock(&pers_lock);
6925 		list_for_each_entry(pers, &pers_list, list)
6926 			seq_printf(seq, "[%s] ", pers->name);
6927 
6928 		spin_unlock(&pers_lock);
6929 		seq_printf(seq, "\n");
6930 		seq->poll_event = atomic_read(&md_event_count);
6931 		return 0;
6932 	}
6933 	if (v == (void*)2) {
6934 		status_unused(seq);
6935 		return 0;
6936 	}
6937 
6938 	if (mddev_lock(mddev) < 0)
6939 		return -EINTR;
6940 
6941 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6942 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6943 						mddev->pers ? "" : "in");
6944 		if (mddev->pers) {
6945 			if (mddev->ro==1)
6946 				seq_printf(seq, " (read-only)");
6947 			if (mddev->ro==2)
6948 				seq_printf(seq, " (auto-read-only)");
6949 			seq_printf(seq, " %s", mddev->pers->name);
6950 		}
6951 
6952 		sectors = 0;
6953 		rdev_for_each(rdev, mddev) {
6954 			char b[BDEVNAME_SIZE];
6955 			seq_printf(seq, " %s[%d]",
6956 				bdevname(rdev->bdev,b), rdev->desc_nr);
6957 			if (test_bit(WriteMostly, &rdev->flags))
6958 				seq_printf(seq, "(W)");
6959 			if (test_bit(Faulty, &rdev->flags)) {
6960 				seq_printf(seq, "(F)");
6961 				continue;
6962 			}
6963 			if (rdev->raid_disk < 0)
6964 				seq_printf(seq, "(S)"); /* spare */
6965 			if (test_bit(Replacement, &rdev->flags))
6966 				seq_printf(seq, "(R)");
6967 			sectors += rdev->sectors;
6968 		}
6969 
6970 		if (!list_empty(&mddev->disks)) {
6971 			if (mddev->pers)
6972 				seq_printf(seq, "\n      %llu blocks",
6973 					   (unsigned long long)
6974 					   mddev->array_sectors / 2);
6975 			else
6976 				seq_printf(seq, "\n      %llu blocks",
6977 					   (unsigned long long)sectors / 2);
6978 		}
6979 		if (mddev->persistent) {
6980 			if (mddev->major_version != 0 ||
6981 			    mddev->minor_version != 90) {
6982 				seq_printf(seq," super %d.%d",
6983 					   mddev->major_version,
6984 					   mddev->minor_version);
6985 			}
6986 		} else if (mddev->external)
6987 			seq_printf(seq, " super external:%s",
6988 				   mddev->metadata_type);
6989 		else
6990 			seq_printf(seq, " super non-persistent");
6991 
6992 		if (mddev->pers) {
6993 			mddev->pers->status(seq, mddev);
6994 	 		seq_printf(seq, "\n      ");
6995 			if (mddev->pers->sync_request) {
6996 				if (mddev->curr_resync > 2) {
6997 					status_resync(seq, mddev);
6998 					seq_printf(seq, "\n      ");
6999 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
7000 					seq_printf(seq, "\tresync=DELAYED\n      ");
7001 				else if (mddev->recovery_cp < MaxSector)
7002 					seq_printf(seq, "\tresync=PENDING\n      ");
7003 			}
7004 		} else
7005 			seq_printf(seq, "\n       ");
7006 
7007 		bitmap_status(seq, mddev->bitmap);
7008 
7009 		seq_printf(seq, "\n");
7010 	}
7011 	mddev_unlock(mddev);
7012 
7013 	return 0;
7014 }
7015 
7016 static const struct seq_operations md_seq_ops = {
7017 	.start  = md_seq_start,
7018 	.next   = md_seq_next,
7019 	.stop   = md_seq_stop,
7020 	.show   = md_seq_show,
7021 };
7022 
7023 static int md_seq_open(struct inode *inode, struct file *file)
7024 {
7025 	struct seq_file *seq;
7026 	int error;
7027 
7028 	error = seq_open(file, &md_seq_ops);
7029 	if (error)
7030 		return error;
7031 
7032 	seq = file->private_data;
7033 	seq->poll_event = atomic_read(&md_event_count);
7034 	return error;
7035 }
7036 
7037 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7038 {
7039 	struct seq_file *seq = filp->private_data;
7040 	int mask;
7041 
7042 	poll_wait(filp, &md_event_waiters, wait);
7043 
7044 	/* always allow read */
7045 	mask = POLLIN | POLLRDNORM;
7046 
7047 	if (seq->poll_event != atomic_read(&md_event_count))
7048 		mask |= POLLERR | POLLPRI;
7049 	return mask;
7050 }
7051 
7052 static const struct file_operations md_seq_fops = {
7053 	.owner		= THIS_MODULE,
7054 	.open           = md_seq_open,
7055 	.read           = seq_read,
7056 	.llseek         = seq_lseek,
7057 	.release	= seq_release_private,
7058 	.poll		= mdstat_poll,
7059 };
7060 
7061 int register_md_personality(struct md_personality *p)
7062 {
7063 	spin_lock(&pers_lock);
7064 	list_add_tail(&p->list, &pers_list);
7065 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
7066 	spin_unlock(&pers_lock);
7067 	return 0;
7068 }
7069 
7070 int unregister_md_personality(struct md_personality *p)
7071 {
7072 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
7073 	spin_lock(&pers_lock);
7074 	list_del_init(&p->list);
7075 	spin_unlock(&pers_lock);
7076 	return 0;
7077 }
7078 
7079 static int is_mddev_idle(struct mddev *mddev, int init)
7080 {
7081 	struct md_rdev * rdev;
7082 	int idle;
7083 	int curr_events;
7084 
7085 	idle = 1;
7086 	rcu_read_lock();
7087 	rdev_for_each_rcu(rdev, mddev) {
7088 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
7089 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
7090 			      (int)part_stat_read(&disk->part0, sectors[1]) -
7091 			      atomic_read(&disk->sync_io);
7092 		/* sync IO will cause sync_io to increase before the disk_stats
7093 		 * as sync_io is counted when a request starts, and
7094 		 * disk_stats is counted when it completes.
7095 		 * So resync activity will cause curr_events to be smaller than
7096 		 * when there was no such activity.
7097 		 * non-sync IO will cause disk_stat to increase without
7098 		 * increasing sync_io so curr_events will (eventually)
7099 		 * be larger than it was before.  Once it becomes
7100 		 * substantially larger, the test below will cause
7101 		 * the array to appear non-idle, and resync will slow
7102 		 * down.
7103 		 * If there is a lot of outstanding resync activity when
7104 		 * we set last_event to curr_events, then all that activity
7105 		 * completing might cause the array to appear non-idle
7106 		 * and resync will be slowed down even though there might
7107 		 * not have been non-resync activity.  This will only
7108 		 * happen once though.  'last_events' will soon reflect
7109 		 * the state where there is little or no outstanding
7110 		 * resync requests, and further resync activity will
7111 		 * always make curr_events less than last_events.
7112 		 *
7113 		 */
7114 		if (init || curr_events - rdev->last_events > 64) {
7115 			rdev->last_events = curr_events;
7116 			idle = 0;
7117 		}
7118 	}
7119 	rcu_read_unlock();
7120 	return idle;
7121 }
7122 
7123 void md_done_sync(struct mddev *mddev, int blocks, int ok)
7124 {
7125 	/* another "blocks" (512byte) blocks have been synced */
7126 	atomic_sub(blocks, &mddev->recovery_active);
7127 	wake_up(&mddev->recovery_wait);
7128 	if (!ok) {
7129 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7130 		md_wakeup_thread(mddev->thread);
7131 		// stop recovery, signal do_sync ....
7132 	}
7133 }
7134 
7135 
7136 /* md_write_start(mddev, bi)
7137  * If we need to update some array metadata (e.g. 'active' flag
7138  * in superblock) before writing, schedule a superblock update
7139  * and wait for it to complete.
7140  */
7141 void md_write_start(struct mddev *mddev, struct bio *bi)
7142 {
7143 	int did_change = 0;
7144 	if (bio_data_dir(bi) != WRITE)
7145 		return;
7146 
7147 	BUG_ON(mddev->ro == 1);
7148 	if (mddev->ro == 2) {
7149 		/* need to switch to read/write */
7150 		mddev->ro = 0;
7151 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7152 		md_wakeup_thread(mddev->thread);
7153 		md_wakeup_thread(mddev->sync_thread);
7154 		did_change = 1;
7155 	}
7156 	atomic_inc(&mddev->writes_pending);
7157 	if (mddev->safemode == 1)
7158 		mddev->safemode = 0;
7159 	if (mddev->in_sync) {
7160 		spin_lock_irq(&mddev->write_lock);
7161 		if (mddev->in_sync) {
7162 			mddev->in_sync = 0;
7163 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7164 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
7165 			md_wakeup_thread(mddev->thread);
7166 			did_change = 1;
7167 		}
7168 		spin_unlock_irq(&mddev->write_lock);
7169 	}
7170 	if (did_change)
7171 		sysfs_notify_dirent_safe(mddev->sysfs_state);
7172 	wait_event(mddev->sb_wait,
7173 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
7174 }
7175 
7176 void md_write_end(struct mddev *mddev)
7177 {
7178 	if (atomic_dec_and_test(&mddev->writes_pending)) {
7179 		if (mddev->safemode == 2)
7180 			md_wakeup_thread(mddev->thread);
7181 		else if (mddev->safemode_delay)
7182 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
7183 	}
7184 }
7185 
7186 /* md_allow_write(mddev)
7187  * Calling this ensures that the array is marked 'active' so that writes
7188  * may proceed without blocking.  It is important to call this before
7189  * attempting a GFP_KERNEL allocation while holding the mddev lock.
7190  * Must be called with mddev_lock held.
7191  *
7192  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
7193  * is dropped, so return -EAGAIN after notifying userspace.
7194  */
7195 int md_allow_write(struct mddev *mddev)
7196 {
7197 	if (!mddev->pers)
7198 		return 0;
7199 	if (mddev->ro)
7200 		return 0;
7201 	if (!mddev->pers->sync_request)
7202 		return 0;
7203 
7204 	spin_lock_irq(&mddev->write_lock);
7205 	if (mddev->in_sync) {
7206 		mddev->in_sync = 0;
7207 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7208 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
7209 		if (mddev->safemode_delay &&
7210 		    mddev->safemode == 0)
7211 			mddev->safemode = 1;
7212 		spin_unlock_irq(&mddev->write_lock);
7213 		md_update_sb(mddev, 0);
7214 		sysfs_notify_dirent_safe(mddev->sysfs_state);
7215 	} else
7216 		spin_unlock_irq(&mddev->write_lock);
7217 
7218 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
7219 		return -EAGAIN;
7220 	else
7221 		return 0;
7222 }
7223 EXPORT_SYMBOL_GPL(md_allow_write);
7224 
7225 #define SYNC_MARKS	10
7226 #define	SYNC_MARK_STEP	(3*HZ)
7227 void md_do_sync(struct mddev *mddev)
7228 {
7229 	struct mddev *mddev2;
7230 	unsigned int currspeed = 0,
7231 		 window;
7232 	sector_t max_sectors,j, io_sectors;
7233 	unsigned long mark[SYNC_MARKS];
7234 	sector_t mark_cnt[SYNC_MARKS];
7235 	int last_mark,m;
7236 	struct list_head *tmp;
7237 	sector_t last_check;
7238 	int skipped = 0;
7239 	struct md_rdev *rdev;
7240 	char *desc;
7241 	struct blk_plug plug;
7242 
7243 	/* just incase thread restarts... */
7244 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7245 		return;
7246 	if (mddev->ro) /* never try to sync a read-only array */
7247 		return;
7248 
7249 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7250 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
7251 			desc = "data-check";
7252 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7253 			desc = "requested-resync";
7254 		else
7255 			desc = "resync";
7256 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7257 		desc = "reshape";
7258 	else
7259 		desc = "recovery";
7260 
7261 	/* we overload curr_resync somewhat here.
7262 	 * 0 == not engaged in resync at all
7263 	 * 2 == checking that there is no conflict with another sync
7264 	 * 1 == like 2, but have yielded to allow conflicting resync to
7265 	 *		commense
7266 	 * other == active in resync - this many blocks
7267 	 *
7268 	 * Before starting a resync we must have set curr_resync to
7269 	 * 2, and then checked that every "conflicting" array has curr_resync
7270 	 * less than ours.  When we find one that is the same or higher
7271 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
7272 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
7273 	 * This will mean we have to start checking from the beginning again.
7274 	 *
7275 	 */
7276 
7277 	do {
7278 		mddev->curr_resync = 2;
7279 
7280 	try_again:
7281 		if (kthread_should_stop())
7282 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7283 
7284 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7285 			goto skip;
7286 		for_each_mddev(mddev2, tmp) {
7287 			if (mddev2 == mddev)
7288 				continue;
7289 			if (!mddev->parallel_resync
7290 			&&  mddev2->curr_resync
7291 			&&  match_mddev_units(mddev, mddev2)) {
7292 				DEFINE_WAIT(wq);
7293 				if (mddev < mddev2 && mddev->curr_resync == 2) {
7294 					/* arbitrarily yield */
7295 					mddev->curr_resync = 1;
7296 					wake_up(&resync_wait);
7297 				}
7298 				if (mddev > mddev2 && mddev->curr_resync == 1)
7299 					/* no need to wait here, we can wait the next
7300 					 * time 'round when curr_resync == 2
7301 					 */
7302 					continue;
7303 				/* We need to wait 'interruptible' so as not to
7304 				 * contribute to the load average, and not to
7305 				 * be caught by 'softlockup'
7306 				 */
7307 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7308 				if (!kthread_should_stop() &&
7309 				    mddev2->curr_resync >= mddev->curr_resync) {
7310 					printk(KERN_INFO "md: delaying %s of %s"
7311 					       " until %s has finished (they"
7312 					       " share one or more physical units)\n",
7313 					       desc, mdname(mddev), mdname(mddev2));
7314 					mddev_put(mddev2);
7315 					if (signal_pending(current))
7316 						flush_signals(current);
7317 					schedule();
7318 					finish_wait(&resync_wait, &wq);
7319 					goto try_again;
7320 				}
7321 				finish_wait(&resync_wait, &wq);
7322 			}
7323 		}
7324 	} while (mddev->curr_resync < 2);
7325 
7326 	j = 0;
7327 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7328 		/* resync follows the size requested by the personality,
7329 		 * which defaults to physical size, but can be virtual size
7330 		 */
7331 		max_sectors = mddev->resync_max_sectors;
7332 		mddev->resync_mismatches = 0;
7333 		/* we don't use the checkpoint if there's a bitmap */
7334 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7335 			j = mddev->resync_min;
7336 		else if (!mddev->bitmap)
7337 			j = mddev->recovery_cp;
7338 
7339 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7340 		max_sectors = mddev->resync_max_sectors;
7341 	else {
7342 		/* recovery follows the physical size of devices */
7343 		max_sectors = mddev->dev_sectors;
7344 		j = MaxSector;
7345 		rcu_read_lock();
7346 		rdev_for_each_rcu(rdev, mddev)
7347 			if (rdev->raid_disk >= 0 &&
7348 			    !test_bit(Faulty, &rdev->flags) &&
7349 			    !test_bit(In_sync, &rdev->flags) &&
7350 			    rdev->recovery_offset < j)
7351 				j = rdev->recovery_offset;
7352 		rcu_read_unlock();
7353 	}
7354 
7355 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7356 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7357 		" %d KB/sec/disk.\n", speed_min(mddev));
7358 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7359 	       "(but not more than %d KB/sec) for %s.\n",
7360 	       speed_max(mddev), desc);
7361 
7362 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7363 
7364 	io_sectors = 0;
7365 	for (m = 0; m < SYNC_MARKS; m++) {
7366 		mark[m] = jiffies;
7367 		mark_cnt[m] = io_sectors;
7368 	}
7369 	last_mark = 0;
7370 	mddev->resync_mark = mark[last_mark];
7371 	mddev->resync_mark_cnt = mark_cnt[last_mark];
7372 
7373 	/*
7374 	 * Tune reconstruction:
7375 	 */
7376 	window = 32*(PAGE_SIZE/512);
7377 	printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7378 		window/2, (unsigned long long)max_sectors/2);
7379 
7380 	atomic_set(&mddev->recovery_active, 0);
7381 	last_check = 0;
7382 
7383 	if (j>2) {
7384 		printk(KERN_INFO
7385 		       "md: resuming %s of %s from checkpoint.\n",
7386 		       desc, mdname(mddev));
7387 		mddev->curr_resync = j;
7388 	}
7389 	mddev->curr_resync_completed = j;
7390 
7391 	blk_start_plug(&plug);
7392 	while (j < max_sectors) {
7393 		sector_t sectors;
7394 
7395 		skipped = 0;
7396 
7397 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7398 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
7399 		      (mddev->curr_resync - mddev->curr_resync_completed)
7400 		      > (max_sectors >> 4)) ||
7401 		     (j - mddev->curr_resync_completed)*2
7402 		     >= mddev->resync_max - mddev->curr_resync_completed
7403 			    )) {
7404 			/* time to update curr_resync_completed */
7405 			wait_event(mddev->recovery_wait,
7406 				   atomic_read(&mddev->recovery_active) == 0);
7407 			mddev->curr_resync_completed = j;
7408 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7409 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7410 		}
7411 
7412 		while (j >= mddev->resync_max && !kthread_should_stop()) {
7413 			/* As this condition is controlled by user-space,
7414 			 * we can block indefinitely, so use '_interruptible'
7415 			 * to avoid triggering warnings.
7416 			 */
7417 			flush_signals(current); /* just in case */
7418 			wait_event_interruptible(mddev->recovery_wait,
7419 						 mddev->resync_max > j
7420 						 || kthread_should_stop());
7421 		}
7422 
7423 		if (kthread_should_stop())
7424 			goto interrupted;
7425 
7426 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
7427 						  currspeed < speed_min(mddev));
7428 		if (sectors == 0) {
7429 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7430 			goto out;
7431 		}
7432 
7433 		if (!skipped) { /* actual IO requested */
7434 			io_sectors += sectors;
7435 			atomic_add(sectors, &mddev->recovery_active);
7436 		}
7437 
7438 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7439 			break;
7440 
7441 		j += sectors;
7442 		if (j>1) mddev->curr_resync = j;
7443 		mddev->curr_mark_cnt = io_sectors;
7444 		if (last_check == 0)
7445 			/* this is the earliest that rebuild will be
7446 			 * visible in /proc/mdstat
7447 			 */
7448 			md_new_event(mddev);
7449 
7450 		if (last_check + window > io_sectors || j == max_sectors)
7451 			continue;
7452 
7453 		last_check = io_sectors;
7454 	repeat:
7455 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
7456 			/* step marks */
7457 			int next = (last_mark+1) % SYNC_MARKS;
7458 
7459 			mddev->resync_mark = mark[next];
7460 			mddev->resync_mark_cnt = mark_cnt[next];
7461 			mark[next] = jiffies;
7462 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
7463 			last_mark = next;
7464 		}
7465 
7466 
7467 		if (kthread_should_stop())
7468 			goto interrupted;
7469 
7470 
7471 		/*
7472 		 * this loop exits only if either when we are slower than
7473 		 * the 'hard' speed limit, or the system was IO-idle for
7474 		 * a jiffy.
7475 		 * the system might be non-idle CPU-wise, but we only care
7476 		 * about not overloading the IO subsystem. (things like an
7477 		 * e2fsck being done on the RAID array should execute fast)
7478 		 */
7479 		cond_resched();
7480 
7481 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
7482 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
7483 
7484 		if (currspeed > speed_min(mddev)) {
7485 			if ((currspeed > speed_max(mddev)) ||
7486 					!is_mddev_idle(mddev, 0)) {
7487 				msleep(500);
7488 				goto repeat;
7489 			}
7490 		}
7491 	}
7492 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
7493 	/*
7494 	 * this also signals 'finished resyncing' to md_stop
7495 	 */
7496  out:
7497 	blk_finish_plug(&plug);
7498 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
7499 
7500 	/* tell personality that we are finished */
7501 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
7502 
7503 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
7504 	    mddev->curr_resync > 2) {
7505 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7506 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7507 				if (mddev->curr_resync >= mddev->recovery_cp) {
7508 					printk(KERN_INFO
7509 					       "md: checkpointing %s of %s.\n",
7510 					       desc, mdname(mddev));
7511 					mddev->recovery_cp =
7512 						mddev->curr_resync_completed;
7513 				}
7514 			} else
7515 				mddev->recovery_cp = MaxSector;
7516 		} else {
7517 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7518 				mddev->curr_resync = MaxSector;
7519 			rcu_read_lock();
7520 			rdev_for_each_rcu(rdev, mddev)
7521 				if (rdev->raid_disk >= 0 &&
7522 				    mddev->delta_disks >= 0 &&
7523 				    !test_bit(Faulty, &rdev->flags) &&
7524 				    !test_bit(In_sync, &rdev->flags) &&
7525 				    rdev->recovery_offset < mddev->curr_resync)
7526 					rdev->recovery_offset = mddev->curr_resync;
7527 			rcu_read_unlock();
7528 		}
7529 	}
7530  skip:
7531 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
7532 
7533 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7534 		/* We completed so min/max setting can be forgotten if used. */
7535 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7536 			mddev->resync_min = 0;
7537 		mddev->resync_max = MaxSector;
7538 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7539 		mddev->resync_min = mddev->curr_resync_completed;
7540 	mddev->curr_resync = 0;
7541 	wake_up(&resync_wait);
7542 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
7543 	md_wakeup_thread(mddev->thread);
7544 	return;
7545 
7546  interrupted:
7547 	/*
7548 	 * got a signal, exit.
7549 	 */
7550 	printk(KERN_INFO
7551 	       "md: md_do_sync() got signal ... exiting\n");
7552 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7553 	goto out;
7554 
7555 }
7556 EXPORT_SYMBOL_GPL(md_do_sync);
7557 
7558 static int remove_and_add_spares(struct mddev *mddev)
7559 {
7560 	struct md_rdev *rdev;
7561 	int spares = 0;
7562 	int removed = 0;
7563 
7564 	mddev->curr_resync_completed = 0;
7565 
7566 	rdev_for_each(rdev, mddev)
7567 		if (rdev->raid_disk >= 0 &&
7568 		    !test_bit(Blocked, &rdev->flags) &&
7569 		    (test_bit(Faulty, &rdev->flags) ||
7570 		     ! test_bit(In_sync, &rdev->flags)) &&
7571 		    atomic_read(&rdev->nr_pending)==0) {
7572 			if (mddev->pers->hot_remove_disk(
7573 				    mddev, rdev) == 0) {
7574 				sysfs_unlink_rdev(mddev, rdev);
7575 				rdev->raid_disk = -1;
7576 				removed++;
7577 			}
7578 		}
7579 	if (removed)
7580 		sysfs_notify(&mddev->kobj, NULL,
7581 			     "degraded");
7582 
7583 
7584 	rdev_for_each(rdev, mddev) {
7585 		if (rdev->raid_disk >= 0 &&
7586 		    !test_bit(In_sync, &rdev->flags) &&
7587 		    !test_bit(Faulty, &rdev->flags))
7588 			spares++;
7589 		if (rdev->raid_disk < 0
7590 		    && !test_bit(Faulty, &rdev->flags)) {
7591 			rdev->recovery_offset = 0;
7592 			if (mddev->pers->
7593 			    hot_add_disk(mddev, rdev) == 0) {
7594 				if (sysfs_link_rdev(mddev, rdev))
7595 					/* failure here is OK */;
7596 				spares++;
7597 				md_new_event(mddev);
7598 				set_bit(MD_CHANGE_DEVS, &mddev->flags);
7599 			}
7600 		}
7601 	}
7602 	return spares;
7603 }
7604 
7605 static void reap_sync_thread(struct mddev *mddev)
7606 {
7607 	struct md_rdev *rdev;
7608 
7609 	/* resync has finished, collect result */
7610 	md_unregister_thread(&mddev->sync_thread);
7611 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7612 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7613 		/* success...*/
7614 		/* activate any spares */
7615 		if (mddev->pers->spare_active(mddev))
7616 			sysfs_notify(&mddev->kobj, NULL,
7617 				     "degraded");
7618 	}
7619 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7620 	    mddev->pers->finish_reshape)
7621 		mddev->pers->finish_reshape(mddev);
7622 
7623 	/* If array is no-longer degraded, then any saved_raid_disk
7624 	 * information must be scrapped.  Also if any device is now
7625 	 * In_sync we must scrape the saved_raid_disk for that device
7626 	 * do the superblock for an incrementally recovered device
7627 	 * written out.
7628 	 */
7629 	rdev_for_each(rdev, mddev)
7630 		if (!mddev->degraded ||
7631 		    test_bit(In_sync, &rdev->flags))
7632 			rdev->saved_raid_disk = -1;
7633 
7634 	md_update_sb(mddev, 1);
7635 	clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7636 	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7637 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7638 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7639 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7640 	/* flag recovery needed just to double check */
7641 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7642 	sysfs_notify_dirent_safe(mddev->sysfs_action);
7643 	md_new_event(mddev);
7644 	if (mddev->event_work.func)
7645 		queue_work(md_misc_wq, &mddev->event_work);
7646 }
7647 
7648 /*
7649  * This routine is regularly called by all per-raid-array threads to
7650  * deal with generic issues like resync and super-block update.
7651  * Raid personalities that don't have a thread (linear/raid0) do not
7652  * need this as they never do any recovery or update the superblock.
7653  *
7654  * It does not do any resync itself, but rather "forks" off other threads
7655  * to do that as needed.
7656  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7657  * "->recovery" and create a thread at ->sync_thread.
7658  * When the thread finishes it sets MD_RECOVERY_DONE
7659  * and wakeups up this thread which will reap the thread and finish up.
7660  * This thread also removes any faulty devices (with nr_pending == 0).
7661  *
7662  * The overall approach is:
7663  *  1/ if the superblock needs updating, update it.
7664  *  2/ If a recovery thread is running, don't do anything else.
7665  *  3/ If recovery has finished, clean up, possibly marking spares active.
7666  *  4/ If there are any faulty devices, remove them.
7667  *  5/ If array is degraded, try to add spares devices
7668  *  6/ If array has spares or is not in-sync, start a resync thread.
7669  */
7670 void md_check_recovery(struct mddev *mddev)
7671 {
7672 	if (mddev->suspended)
7673 		return;
7674 
7675 	if (mddev->bitmap)
7676 		bitmap_daemon_work(mddev);
7677 
7678 	if (signal_pending(current)) {
7679 		if (mddev->pers->sync_request && !mddev->external) {
7680 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7681 			       mdname(mddev));
7682 			mddev->safemode = 2;
7683 		}
7684 		flush_signals(current);
7685 	}
7686 
7687 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7688 		return;
7689 	if ( ! (
7690 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7691 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7692 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7693 		(mddev->external == 0 && mddev->safemode == 1) ||
7694 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7695 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7696 		))
7697 		return;
7698 
7699 	if (mddev_trylock(mddev)) {
7700 		int spares = 0;
7701 
7702 		if (mddev->ro) {
7703 			/* Only thing we do on a ro array is remove
7704 			 * failed devices.
7705 			 */
7706 			struct md_rdev *rdev;
7707 			rdev_for_each(rdev, mddev)
7708 				if (rdev->raid_disk >= 0 &&
7709 				    !test_bit(Blocked, &rdev->flags) &&
7710 				    test_bit(Faulty, &rdev->flags) &&
7711 				    atomic_read(&rdev->nr_pending)==0) {
7712 					if (mddev->pers->hot_remove_disk(
7713 						    mddev, rdev) == 0) {
7714 						sysfs_unlink_rdev(mddev, rdev);
7715 						rdev->raid_disk = -1;
7716 					}
7717 				}
7718 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7719 			goto unlock;
7720 		}
7721 
7722 		if (!mddev->external) {
7723 			int did_change = 0;
7724 			spin_lock_irq(&mddev->write_lock);
7725 			if (mddev->safemode &&
7726 			    !atomic_read(&mddev->writes_pending) &&
7727 			    !mddev->in_sync &&
7728 			    mddev->recovery_cp == MaxSector) {
7729 				mddev->in_sync = 1;
7730 				did_change = 1;
7731 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7732 			}
7733 			if (mddev->safemode == 1)
7734 				mddev->safemode = 0;
7735 			spin_unlock_irq(&mddev->write_lock);
7736 			if (did_change)
7737 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7738 		}
7739 
7740 		if (mddev->flags)
7741 			md_update_sb(mddev, 0);
7742 
7743 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7744 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7745 			/* resync/recovery still happening */
7746 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7747 			goto unlock;
7748 		}
7749 		if (mddev->sync_thread) {
7750 			reap_sync_thread(mddev);
7751 			goto unlock;
7752 		}
7753 		/* Set RUNNING before clearing NEEDED to avoid
7754 		 * any transients in the value of "sync_action".
7755 		 */
7756 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7757 		/* Clear some bits that don't mean anything, but
7758 		 * might be left set
7759 		 */
7760 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7761 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7762 
7763 		if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7764 		    test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7765 			goto unlock;
7766 		/* no recovery is running.
7767 		 * remove any failed drives, then
7768 		 * add spares if possible.
7769 		 * Spare are also removed and re-added, to allow
7770 		 * the personality to fail the re-add.
7771 		 */
7772 
7773 		if (mddev->reshape_position != MaxSector) {
7774 			if (mddev->pers->check_reshape == NULL ||
7775 			    mddev->pers->check_reshape(mddev) != 0)
7776 				/* Cannot proceed */
7777 				goto unlock;
7778 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7779 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7780 		} else if ((spares = remove_and_add_spares(mddev))) {
7781 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7782 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7783 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7784 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7785 		} else if (mddev->recovery_cp < MaxSector) {
7786 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7787 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7788 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7789 			/* nothing to be done ... */
7790 			goto unlock;
7791 
7792 		if (mddev->pers->sync_request) {
7793 			if (spares) {
7794 				/* We are adding a device or devices to an array
7795 				 * which has the bitmap stored on all devices.
7796 				 * So make sure all bitmap pages get written
7797 				 */
7798 				bitmap_write_all(mddev->bitmap);
7799 			}
7800 			mddev->sync_thread = md_register_thread(md_do_sync,
7801 								mddev,
7802 								"resync");
7803 			if (!mddev->sync_thread) {
7804 				printk(KERN_ERR "%s: could not start resync"
7805 					" thread...\n",
7806 					mdname(mddev));
7807 				/* leave the spares where they are, it shouldn't hurt */
7808 				clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7809 				clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7810 				clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7811 				clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7812 				clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7813 			} else
7814 				md_wakeup_thread(mddev->sync_thread);
7815 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7816 			md_new_event(mddev);
7817 		}
7818 	unlock:
7819 		if (!mddev->sync_thread) {
7820 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7821 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7822 					       &mddev->recovery))
7823 				if (mddev->sysfs_action)
7824 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7825 		}
7826 		mddev_unlock(mddev);
7827 	}
7828 }
7829 
7830 void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
7831 {
7832 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7833 	wait_event_timeout(rdev->blocked_wait,
7834 			   !test_bit(Blocked, &rdev->flags) &&
7835 			   !test_bit(BlockedBadBlocks, &rdev->flags),
7836 			   msecs_to_jiffies(5000));
7837 	rdev_dec_pending(rdev, mddev);
7838 }
7839 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7840 
7841 void md_finish_reshape(struct mddev *mddev)
7842 {
7843 	/* called be personality module when reshape completes. */
7844 	struct md_rdev *rdev;
7845 
7846 	rdev_for_each(rdev, mddev) {
7847 		if (rdev->data_offset > rdev->new_data_offset)
7848 			rdev->sectors += rdev->data_offset - rdev->new_data_offset;
7849 		else
7850 			rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
7851 		rdev->data_offset = rdev->new_data_offset;
7852 	}
7853 }
7854 EXPORT_SYMBOL(md_finish_reshape);
7855 
7856 /* Bad block management.
7857  * We can record which blocks on each device are 'bad' and so just
7858  * fail those blocks, or that stripe, rather than the whole device.
7859  * Entries in the bad-block table are 64bits wide.  This comprises:
7860  * Length of bad-range, in sectors: 0-511 for lengths 1-512
7861  * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
7862  *  A 'shift' can be set so that larger blocks are tracked and
7863  *  consequently larger devices can be covered.
7864  * 'Acknowledged' flag - 1 bit. - the most significant bit.
7865  *
7866  * Locking of the bad-block table uses a seqlock so md_is_badblock
7867  * might need to retry if it is very unlucky.
7868  * We will sometimes want to check for bad blocks in a bi_end_io function,
7869  * so we use the write_seqlock_irq variant.
7870  *
7871  * When looking for a bad block we specify a range and want to
7872  * know if any block in the range is bad.  So we binary-search
7873  * to the last range that starts at-or-before the given endpoint,
7874  * (or "before the sector after the target range")
7875  * then see if it ends after the given start.
7876  * We return
7877  *  0 if there are no known bad blocks in the range
7878  *  1 if there are known bad block which are all acknowledged
7879  * -1 if there are bad blocks which have not yet been acknowledged in metadata.
7880  * plus the start/length of the first bad section we overlap.
7881  */
7882 int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
7883 		   sector_t *first_bad, int *bad_sectors)
7884 {
7885 	int hi;
7886 	int lo = 0;
7887 	u64 *p = bb->page;
7888 	int rv = 0;
7889 	sector_t target = s + sectors;
7890 	unsigned seq;
7891 
7892 	if (bb->shift > 0) {
7893 		/* round the start down, and the end up */
7894 		s >>= bb->shift;
7895 		target += (1<<bb->shift) - 1;
7896 		target >>= bb->shift;
7897 		sectors = target - s;
7898 	}
7899 	/* 'target' is now the first block after the bad range */
7900 
7901 retry:
7902 	seq = read_seqbegin(&bb->lock);
7903 
7904 	hi = bb->count;
7905 
7906 	/* Binary search between lo and hi for 'target'
7907 	 * i.e. for the last range that starts before 'target'
7908 	 */
7909 	/* INVARIANT: ranges before 'lo' and at-or-after 'hi'
7910 	 * are known not to be the last range before target.
7911 	 * VARIANT: hi-lo is the number of possible
7912 	 * ranges, and decreases until it reaches 1
7913 	 */
7914 	while (hi - lo > 1) {
7915 		int mid = (lo + hi) / 2;
7916 		sector_t a = BB_OFFSET(p[mid]);
7917 		if (a < target)
7918 			/* This could still be the one, earlier ranges
7919 			 * could not. */
7920 			lo = mid;
7921 		else
7922 			/* This and later ranges are definitely out. */
7923 			hi = mid;
7924 	}
7925 	/* 'lo' might be the last that started before target, but 'hi' isn't */
7926 	if (hi > lo) {
7927 		/* need to check all range that end after 's' to see if
7928 		 * any are unacknowledged.
7929 		 */
7930 		while (lo >= 0 &&
7931 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7932 			if (BB_OFFSET(p[lo]) < target) {
7933 				/* starts before the end, and finishes after
7934 				 * the start, so they must overlap
7935 				 */
7936 				if (rv != -1 && BB_ACK(p[lo]))
7937 					rv = 1;
7938 				else
7939 					rv = -1;
7940 				*first_bad = BB_OFFSET(p[lo]);
7941 				*bad_sectors = BB_LEN(p[lo]);
7942 			}
7943 			lo--;
7944 		}
7945 	}
7946 
7947 	if (read_seqretry(&bb->lock, seq))
7948 		goto retry;
7949 
7950 	return rv;
7951 }
7952 EXPORT_SYMBOL_GPL(md_is_badblock);
7953 
7954 /*
7955  * Add a range of bad blocks to the table.
7956  * This might extend the table, or might contract it
7957  * if two adjacent ranges can be merged.
7958  * We binary-search to find the 'insertion' point, then
7959  * decide how best to handle it.
7960  */
7961 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
7962 			    int acknowledged)
7963 {
7964 	u64 *p;
7965 	int lo, hi;
7966 	int rv = 1;
7967 
7968 	if (bb->shift < 0)
7969 		/* badblocks are disabled */
7970 		return 0;
7971 
7972 	if (bb->shift) {
7973 		/* round the start down, and the end up */
7974 		sector_t next = s + sectors;
7975 		s >>= bb->shift;
7976 		next += (1<<bb->shift) - 1;
7977 		next >>= bb->shift;
7978 		sectors = next - s;
7979 	}
7980 
7981 	write_seqlock_irq(&bb->lock);
7982 
7983 	p = bb->page;
7984 	lo = 0;
7985 	hi = bb->count;
7986 	/* Find the last range that starts at-or-before 's' */
7987 	while (hi - lo > 1) {
7988 		int mid = (lo + hi) / 2;
7989 		sector_t a = BB_OFFSET(p[mid]);
7990 		if (a <= s)
7991 			lo = mid;
7992 		else
7993 			hi = mid;
7994 	}
7995 	if (hi > lo && BB_OFFSET(p[lo]) > s)
7996 		hi = lo;
7997 
7998 	if (hi > lo) {
7999 		/* we found a range that might merge with the start
8000 		 * of our new range
8001 		 */
8002 		sector_t a = BB_OFFSET(p[lo]);
8003 		sector_t e = a + BB_LEN(p[lo]);
8004 		int ack = BB_ACK(p[lo]);
8005 		if (e >= s) {
8006 			/* Yes, we can merge with a previous range */
8007 			if (s == a && s + sectors >= e)
8008 				/* new range covers old */
8009 				ack = acknowledged;
8010 			else
8011 				ack = ack && acknowledged;
8012 
8013 			if (e < s + sectors)
8014 				e = s + sectors;
8015 			if (e - a <= BB_MAX_LEN) {
8016 				p[lo] = BB_MAKE(a, e-a, ack);
8017 				s = e;
8018 			} else {
8019 				/* does not all fit in one range,
8020 				 * make p[lo] maximal
8021 				 */
8022 				if (BB_LEN(p[lo]) != BB_MAX_LEN)
8023 					p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
8024 				s = a + BB_MAX_LEN;
8025 			}
8026 			sectors = e - s;
8027 		}
8028 	}
8029 	if (sectors && hi < bb->count) {
8030 		/* 'hi' points to the first range that starts after 's'.
8031 		 * Maybe we can merge with the start of that range */
8032 		sector_t a = BB_OFFSET(p[hi]);
8033 		sector_t e = a + BB_LEN(p[hi]);
8034 		int ack = BB_ACK(p[hi]);
8035 		if (a <= s + sectors) {
8036 			/* merging is possible */
8037 			if (e <= s + sectors) {
8038 				/* full overlap */
8039 				e = s + sectors;
8040 				ack = acknowledged;
8041 			} else
8042 				ack = ack && acknowledged;
8043 
8044 			a = s;
8045 			if (e - a <= BB_MAX_LEN) {
8046 				p[hi] = BB_MAKE(a, e-a, ack);
8047 				s = e;
8048 			} else {
8049 				p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
8050 				s = a + BB_MAX_LEN;
8051 			}
8052 			sectors = e - s;
8053 			lo = hi;
8054 			hi++;
8055 		}
8056 	}
8057 	if (sectors == 0 && hi < bb->count) {
8058 		/* we might be able to combine lo and hi */
8059 		/* Note: 's' is at the end of 'lo' */
8060 		sector_t a = BB_OFFSET(p[hi]);
8061 		int lolen = BB_LEN(p[lo]);
8062 		int hilen = BB_LEN(p[hi]);
8063 		int newlen = lolen + hilen - (s - a);
8064 		if (s >= a && newlen < BB_MAX_LEN) {
8065 			/* yes, we can combine them */
8066 			int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
8067 			p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
8068 			memmove(p + hi, p + hi + 1,
8069 				(bb->count - hi - 1) * 8);
8070 			bb->count--;
8071 		}
8072 	}
8073 	while (sectors) {
8074 		/* didn't merge (it all).
8075 		 * Need to add a range just before 'hi' */
8076 		if (bb->count >= MD_MAX_BADBLOCKS) {
8077 			/* No room for more */
8078 			rv = 0;
8079 			break;
8080 		} else {
8081 			int this_sectors = sectors;
8082 			memmove(p + hi + 1, p + hi,
8083 				(bb->count - hi) * 8);
8084 			bb->count++;
8085 
8086 			if (this_sectors > BB_MAX_LEN)
8087 				this_sectors = BB_MAX_LEN;
8088 			p[hi] = BB_MAKE(s, this_sectors, acknowledged);
8089 			sectors -= this_sectors;
8090 			s += this_sectors;
8091 		}
8092 	}
8093 
8094 	bb->changed = 1;
8095 	if (!acknowledged)
8096 		bb->unacked_exist = 1;
8097 	write_sequnlock_irq(&bb->lock);
8098 
8099 	return rv;
8100 }
8101 
8102 int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8103 		       int is_new)
8104 {
8105 	int rv;
8106 	if (is_new)
8107 		s += rdev->new_data_offset;
8108 	else
8109 		s += rdev->data_offset;
8110 	rv = md_set_badblocks(&rdev->badblocks,
8111 			      s, sectors, 0);
8112 	if (rv) {
8113 		/* Make sure they get written out promptly */
8114 		sysfs_notify_dirent_safe(rdev->sysfs_state);
8115 		set_bit(MD_CHANGE_CLEAN, &rdev->mddev->flags);
8116 		md_wakeup_thread(rdev->mddev->thread);
8117 	}
8118 	return rv;
8119 }
8120 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
8121 
8122 /*
8123  * Remove a range of bad blocks from the table.
8124  * This may involve extending the table if we spilt a region,
8125  * but it must not fail.  So if the table becomes full, we just
8126  * drop the remove request.
8127  */
8128 static int md_clear_badblocks(struct badblocks *bb, sector_t s, int sectors)
8129 {
8130 	u64 *p;
8131 	int lo, hi;
8132 	sector_t target = s + sectors;
8133 	int rv = 0;
8134 
8135 	if (bb->shift > 0) {
8136 		/* When clearing we round the start up and the end down.
8137 		 * This should not matter as the shift should align with
8138 		 * the block size and no rounding should ever be needed.
8139 		 * However it is better the think a block is bad when it
8140 		 * isn't than to think a block is not bad when it is.
8141 		 */
8142 		s += (1<<bb->shift) - 1;
8143 		s >>= bb->shift;
8144 		target >>= bb->shift;
8145 		sectors = target - s;
8146 	}
8147 
8148 	write_seqlock_irq(&bb->lock);
8149 
8150 	p = bb->page;
8151 	lo = 0;
8152 	hi = bb->count;
8153 	/* Find the last range that starts before 'target' */
8154 	while (hi - lo > 1) {
8155 		int mid = (lo + hi) / 2;
8156 		sector_t a = BB_OFFSET(p[mid]);
8157 		if (a < target)
8158 			lo = mid;
8159 		else
8160 			hi = mid;
8161 	}
8162 	if (hi > lo) {
8163 		/* p[lo] is the last range that could overlap the
8164 		 * current range.  Earlier ranges could also overlap,
8165 		 * but only this one can overlap the end of the range.
8166 		 */
8167 		if (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) {
8168 			/* Partial overlap, leave the tail of this range */
8169 			int ack = BB_ACK(p[lo]);
8170 			sector_t a = BB_OFFSET(p[lo]);
8171 			sector_t end = a + BB_LEN(p[lo]);
8172 
8173 			if (a < s) {
8174 				/* we need to split this range */
8175 				if (bb->count >= MD_MAX_BADBLOCKS) {
8176 					rv = 0;
8177 					goto out;
8178 				}
8179 				memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
8180 				bb->count++;
8181 				p[lo] = BB_MAKE(a, s-a, ack);
8182 				lo++;
8183 			}
8184 			p[lo] = BB_MAKE(target, end - target, ack);
8185 			/* there is no longer an overlap */
8186 			hi = lo;
8187 			lo--;
8188 		}
8189 		while (lo >= 0 &&
8190 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
8191 			/* This range does overlap */
8192 			if (BB_OFFSET(p[lo]) < s) {
8193 				/* Keep the early parts of this range. */
8194 				int ack = BB_ACK(p[lo]);
8195 				sector_t start = BB_OFFSET(p[lo]);
8196 				p[lo] = BB_MAKE(start, s - start, ack);
8197 				/* now low doesn't overlap, so.. */
8198 				break;
8199 			}
8200 			lo--;
8201 		}
8202 		/* 'lo' is strictly before, 'hi' is strictly after,
8203 		 * anything between needs to be discarded
8204 		 */
8205 		if (hi - lo > 1) {
8206 			memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
8207 			bb->count -= (hi - lo - 1);
8208 		}
8209 	}
8210 
8211 	bb->changed = 1;
8212 out:
8213 	write_sequnlock_irq(&bb->lock);
8214 	return rv;
8215 }
8216 
8217 int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
8218 			 int is_new)
8219 {
8220 	if (is_new)
8221 		s += rdev->new_data_offset;
8222 	else
8223 		s += rdev->data_offset;
8224 	return md_clear_badblocks(&rdev->badblocks,
8225 				  s, sectors);
8226 }
8227 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
8228 
8229 /*
8230  * Acknowledge all bad blocks in a list.
8231  * This only succeeds if ->changed is clear.  It is used by
8232  * in-kernel metadata updates
8233  */
8234 void md_ack_all_badblocks(struct badblocks *bb)
8235 {
8236 	if (bb->page == NULL || bb->changed)
8237 		/* no point even trying */
8238 		return;
8239 	write_seqlock_irq(&bb->lock);
8240 
8241 	if (bb->changed == 0 && bb->unacked_exist) {
8242 		u64 *p = bb->page;
8243 		int i;
8244 		for (i = 0; i < bb->count ; i++) {
8245 			if (!BB_ACK(p[i])) {
8246 				sector_t start = BB_OFFSET(p[i]);
8247 				int len = BB_LEN(p[i]);
8248 				p[i] = BB_MAKE(start, len, 1);
8249 			}
8250 		}
8251 		bb->unacked_exist = 0;
8252 	}
8253 	write_sequnlock_irq(&bb->lock);
8254 }
8255 EXPORT_SYMBOL_GPL(md_ack_all_badblocks);
8256 
8257 /* sysfs access to bad-blocks list.
8258  * We present two files.
8259  * 'bad-blocks' lists sector numbers and lengths of ranges that
8260  *    are recorded as bad.  The list is truncated to fit within
8261  *    the one-page limit of sysfs.
8262  *    Writing "sector length" to this file adds an acknowledged
8263  *    bad block list.
8264  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
8265  *    been acknowledged.  Writing to this file adds bad blocks
8266  *    without acknowledging them.  This is largely for testing.
8267  */
8268 
8269 static ssize_t
8270 badblocks_show(struct badblocks *bb, char *page, int unack)
8271 {
8272 	size_t len;
8273 	int i;
8274 	u64 *p = bb->page;
8275 	unsigned seq;
8276 
8277 	if (bb->shift < 0)
8278 		return 0;
8279 
8280 retry:
8281 	seq = read_seqbegin(&bb->lock);
8282 
8283 	len = 0;
8284 	i = 0;
8285 
8286 	while (len < PAGE_SIZE && i < bb->count) {
8287 		sector_t s = BB_OFFSET(p[i]);
8288 		unsigned int length = BB_LEN(p[i]);
8289 		int ack = BB_ACK(p[i]);
8290 		i++;
8291 
8292 		if (unack && ack)
8293 			continue;
8294 
8295 		len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
8296 				(unsigned long long)s << bb->shift,
8297 				length << bb->shift);
8298 	}
8299 	if (unack && len == 0)
8300 		bb->unacked_exist = 0;
8301 
8302 	if (read_seqretry(&bb->lock, seq))
8303 		goto retry;
8304 
8305 	return len;
8306 }
8307 
8308 #define DO_DEBUG 1
8309 
8310 static ssize_t
8311 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack)
8312 {
8313 	unsigned long long sector;
8314 	int length;
8315 	char newline;
8316 #ifdef DO_DEBUG
8317 	/* Allow clearing via sysfs *only* for testing/debugging.
8318 	 * Normally only a successful write may clear a badblock
8319 	 */
8320 	int clear = 0;
8321 	if (page[0] == '-') {
8322 		clear = 1;
8323 		page++;
8324 	}
8325 #endif /* DO_DEBUG */
8326 
8327 	switch (sscanf(page, "%llu %d%c", &sector, &length, &newline)) {
8328 	case 3:
8329 		if (newline != '\n')
8330 			return -EINVAL;
8331 	case 2:
8332 		if (length <= 0)
8333 			return -EINVAL;
8334 		break;
8335 	default:
8336 		return -EINVAL;
8337 	}
8338 
8339 #ifdef DO_DEBUG
8340 	if (clear) {
8341 		md_clear_badblocks(bb, sector, length);
8342 		return len;
8343 	}
8344 #endif /* DO_DEBUG */
8345 	if (md_set_badblocks(bb, sector, length, !unack))
8346 		return len;
8347 	else
8348 		return -ENOSPC;
8349 }
8350 
8351 static int md_notify_reboot(struct notifier_block *this,
8352 			    unsigned long code, void *x)
8353 {
8354 	struct list_head *tmp;
8355 	struct mddev *mddev;
8356 	int need_delay = 0;
8357 
8358 	for_each_mddev(mddev, tmp) {
8359 		if (mddev_trylock(mddev)) {
8360 			if (mddev->pers)
8361 				__md_stop_writes(mddev);
8362 			mddev->safemode = 2;
8363 			mddev_unlock(mddev);
8364 		}
8365 		need_delay = 1;
8366 	}
8367 	/*
8368 	 * certain more exotic SCSI devices are known to be
8369 	 * volatile wrt too early system reboots. While the
8370 	 * right place to handle this issue is the given
8371 	 * driver, we do want to have a safe RAID driver ...
8372 	 */
8373 	if (need_delay)
8374 		mdelay(1000*1);
8375 
8376 	return NOTIFY_DONE;
8377 }
8378 
8379 static struct notifier_block md_notifier = {
8380 	.notifier_call	= md_notify_reboot,
8381 	.next		= NULL,
8382 	.priority	= INT_MAX, /* before any real devices */
8383 };
8384 
8385 static void md_geninit(void)
8386 {
8387 	pr_debug("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
8388 
8389 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
8390 }
8391 
8392 static int __init md_init(void)
8393 {
8394 	int ret = -ENOMEM;
8395 
8396 	md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
8397 	if (!md_wq)
8398 		goto err_wq;
8399 
8400 	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
8401 	if (!md_misc_wq)
8402 		goto err_misc_wq;
8403 
8404 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
8405 		goto err_md;
8406 
8407 	if ((ret = register_blkdev(0, "mdp")) < 0)
8408 		goto err_mdp;
8409 	mdp_major = ret;
8410 
8411 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
8412 			    md_probe, NULL, NULL);
8413 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
8414 			    md_probe, NULL, NULL);
8415 
8416 	register_reboot_notifier(&md_notifier);
8417 	raid_table_header = register_sysctl_table(raid_root_table);
8418 
8419 	md_geninit();
8420 	return 0;
8421 
8422 err_mdp:
8423 	unregister_blkdev(MD_MAJOR, "md");
8424 err_md:
8425 	destroy_workqueue(md_misc_wq);
8426 err_misc_wq:
8427 	destroy_workqueue(md_wq);
8428 err_wq:
8429 	return ret;
8430 }
8431 
8432 #ifndef MODULE
8433 
8434 /*
8435  * Searches all registered partitions for autorun RAID arrays
8436  * at boot time.
8437  */
8438 
8439 static LIST_HEAD(all_detected_devices);
8440 struct detected_devices_node {
8441 	struct list_head list;
8442 	dev_t dev;
8443 };
8444 
8445 void md_autodetect_dev(dev_t dev)
8446 {
8447 	struct detected_devices_node *node_detected_dev;
8448 
8449 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
8450 	if (node_detected_dev) {
8451 		node_detected_dev->dev = dev;
8452 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
8453 	} else {
8454 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
8455 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
8456 	}
8457 }
8458 
8459 
8460 static void autostart_arrays(int part)
8461 {
8462 	struct md_rdev *rdev;
8463 	struct detected_devices_node *node_detected_dev;
8464 	dev_t dev;
8465 	int i_scanned, i_passed;
8466 
8467 	i_scanned = 0;
8468 	i_passed = 0;
8469 
8470 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
8471 
8472 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
8473 		i_scanned++;
8474 		node_detected_dev = list_entry(all_detected_devices.next,
8475 					struct detected_devices_node, list);
8476 		list_del(&node_detected_dev->list);
8477 		dev = node_detected_dev->dev;
8478 		kfree(node_detected_dev);
8479 		rdev = md_import_device(dev,0, 90);
8480 		if (IS_ERR(rdev))
8481 			continue;
8482 
8483 		if (test_bit(Faulty, &rdev->flags)) {
8484 			MD_BUG();
8485 			continue;
8486 		}
8487 		set_bit(AutoDetected, &rdev->flags);
8488 		list_add(&rdev->same_set, &pending_raid_disks);
8489 		i_passed++;
8490 	}
8491 
8492 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
8493 						i_scanned, i_passed);
8494 
8495 	autorun_devices(part);
8496 }
8497 
8498 #endif /* !MODULE */
8499 
8500 static __exit void md_exit(void)
8501 {
8502 	struct mddev *mddev;
8503 	struct list_head *tmp;
8504 
8505 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
8506 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
8507 
8508 	unregister_blkdev(MD_MAJOR,"md");
8509 	unregister_blkdev(mdp_major, "mdp");
8510 	unregister_reboot_notifier(&md_notifier);
8511 	unregister_sysctl_table(raid_table_header);
8512 	remove_proc_entry("mdstat", NULL);
8513 	for_each_mddev(mddev, tmp) {
8514 		export_array(mddev);
8515 		mddev->hold_active = 0;
8516 	}
8517 	destroy_workqueue(md_misc_wq);
8518 	destroy_workqueue(md_wq);
8519 }
8520 
8521 subsys_initcall(md_init);
8522 module_exit(md_exit)
8523 
8524 static int get_ro(char *buffer, struct kernel_param *kp)
8525 {
8526 	return sprintf(buffer, "%d", start_readonly);
8527 }
8528 static int set_ro(const char *val, struct kernel_param *kp)
8529 {
8530 	char *e;
8531 	int num = simple_strtoul(val, &e, 10);
8532 	if (*val && (*e == '\0' || *e == '\n')) {
8533 		start_readonly = num;
8534 		return 0;
8535 	}
8536 	return -EINVAL;
8537 }
8538 
8539 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
8540 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
8541 
8542 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
8543 
8544 EXPORT_SYMBOL(register_md_personality);
8545 EXPORT_SYMBOL(unregister_md_personality);
8546 EXPORT_SYMBOL(md_error);
8547 EXPORT_SYMBOL(md_done_sync);
8548 EXPORT_SYMBOL(md_write_start);
8549 EXPORT_SYMBOL(md_write_end);
8550 EXPORT_SYMBOL(md_register_thread);
8551 EXPORT_SYMBOL(md_unregister_thread);
8552 EXPORT_SYMBOL(md_wakeup_thread);
8553 EXPORT_SYMBOL(md_check_recovery);
8554 MODULE_LICENSE("GPL");
8555 MODULE_DESCRIPTION("MD RAID framework");
8556 MODULE_ALIAS("md");
8557 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
8558