xref: /linux/drivers/md/md.c (revision dde5e3ffb770ef2854bbc32c51a365e932919e19)
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/buffer_head.h> /* for invalidate_bdev */
40 #include <linux/poll.h>
41 #include <linux/ctype.h>
42 #include <linux/hdreg.h>
43 #include <linux/proc_fs.h>
44 #include <linux/random.h>
45 #include <linux/reboot.h>
46 #include <linux/file.h>
47 #include <linux/delay.h>
48 #include <linux/raid/md_p.h>
49 #include <linux/raid/md_u.h>
50 #include "md.h"
51 #include "bitmap.h"
52 
53 #define DEBUG 0
54 #define dprintk(x...) ((void)(DEBUG && printk(x)))
55 
56 
57 #ifndef MODULE
58 static void autostart_arrays(int part);
59 #endif
60 
61 static LIST_HEAD(pers_list);
62 static DEFINE_SPINLOCK(pers_lock);
63 
64 static void md_print_devices(void);
65 
66 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
67 
68 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
69 
70 /*
71  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
72  * is 1000 KB/sec, so the extra system load does not show up that much.
73  * Increase it if you want to have more _guaranteed_ speed. Note that
74  * the RAID driver will use the maximum available bandwidth if the IO
75  * subsystem is idle. There is also an 'absolute maximum' reconstruction
76  * speed limit - in case reconstruction slows down your system despite
77  * idle IO detection.
78  *
79  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
80  * or /sys/block/mdX/md/sync_speed_{min,max}
81  */
82 
83 static int sysctl_speed_limit_min = 1000;
84 static int sysctl_speed_limit_max = 200000;
85 static inline int speed_min(mddev_t *mddev)
86 {
87 	return mddev->sync_speed_min ?
88 		mddev->sync_speed_min : sysctl_speed_limit_min;
89 }
90 
91 static inline int speed_max(mddev_t *mddev)
92 {
93 	return mddev->sync_speed_max ?
94 		mddev->sync_speed_max : sysctl_speed_limit_max;
95 }
96 
97 static struct ctl_table_header *raid_table_header;
98 
99 static ctl_table raid_table[] = {
100 	{
101 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MIN,
102 		.procname	= "speed_limit_min",
103 		.data		= &sysctl_speed_limit_min,
104 		.maxlen		= sizeof(int),
105 		.mode		= S_IRUGO|S_IWUSR,
106 		.proc_handler	= &proc_dointvec,
107 	},
108 	{
109 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MAX,
110 		.procname	= "speed_limit_max",
111 		.data		= &sysctl_speed_limit_max,
112 		.maxlen		= sizeof(int),
113 		.mode		= S_IRUGO|S_IWUSR,
114 		.proc_handler	= &proc_dointvec,
115 	},
116 	{ .ctl_name = 0 }
117 };
118 
119 static ctl_table raid_dir_table[] = {
120 	{
121 		.ctl_name	= DEV_RAID,
122 		.procname	= "raid",
123 		.maxlen		= 0,
124 		.mode		= S_IRUGO|S_IXUGO,
125 		.child		= raid_table,
126 	},
127 	{ .ctl_name = 0 }
128 };
129 
130 static ctl_table raid_root_table[] = {
131 	{
132 		.ctl_name	= CTL_DEV,
133 		.procname	= "dev",
134 		.maxlen		= 0,
135 		.mode		= 0555,
136 		.child		= raid_dir_table,
137 	},
138 	{ .ctl_name = 0 }
139 };
140 
141 static struct block_device_operations md_fops;
142 
143 static int start_readonly;
144 
145 /*
146  * We have a system wide 'event count' that is incremented
147  * on any 'interesting' event, and readers of /proc/mdstat
148  * can use 'poll' or 'select' to find out when the event
149  * count increases.
150  *
151  * Events are:
152  *  start array, stop array, error, add device, remove device,
153  *  start build, activate spare
154  */
155 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
156 static atomic_t md_event_count;
157 void md_new_event(mddev_t *mddev)
158 {
159 	atomic_inc(&md_event_count);
160 	wake_up(&md_event_waiters);
161 }
162 EXPORT_SYMBOL_GPL(md_new_event);
163 
164 /* Alternate version that can be called from interrupts
165  * when calling sysfs_notify isn't needed.
166  */
167 static void md_new_event_inintr(mddev_t *mddev)
168 {
169 	atomic_inc(&md_event_count);
170 	wake_up(&md_event_waiters);
171 }
172 
173 /*
174  * Enables to iterate over all existing md arrays
175  * all_mddevs_lock protects this list.
176  */
177 static LIST_HEAD(all_mddevs);
178 static DEFINE_SPINLOCK(all_mddevs_lock);
179 
180 
181 /*
182  * iterates through all used mddevs in the system.
183  * We take care to grab the all_mddevs_lock whenever navigating
184  * the list, and to always hold a refcount when unlocked.
185  * Any code which breaks out of this loop while own
186  * a reference to the current mddev and must mddev_put it.
187  */
188 #define for_each_mddev(mddev,tmp)					\
189 									\
190 	for (({ spin_lock(&all_mddevs_lock); 				\
191 		tmp = all_mddevs.next;					\
192 		mddev = NULL;});					\
193 	     ({ if (tmp != &all_mddevs)					\
194 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
195 		spin_unlock(&all_mddevs_lock);				\
196 		if (mddev) mddev_put(mddev);				\
197 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
198 		tmp != &all_mddevs;});					\
199 	     ({ spin_lock(&all_mddevs_lock);				\
200 		tmp = tmp->next;})					\
201 		)
202 
203 
204 /* Rather than calling directly into the personality make_request function,
205  * IO requests come here first so that we can check if the device is
206  * being suspended pending a reconfiguration.
207  * We hold a refcount over the call to ->make_request.  By the time that
208  * call has finished, the bio has been linked into some internal structure
209  * and so is visible to ->quiesce(), so we don't need the refcount any more.
210  */
211 static int md_make_request(struct request_queue *q, struct bio *bio)
212 {
213 	mddev_t *mddev = q->queuedata;
214 	int rv;
215 	if (mddev == NULL || mddev->pers == NULL) {
216 		bio_io_error(bio);
217 		return 0;
218 	}
219 	rcu_read_lock();
220 	if (mddev->suspended) {
221 		DEFINE_WAIT(__wait);
222 		for (;;) {
223 			prepare_to_wait(&mddev->sb_wait, &__wait,
224 					TASK_UNINTERRUPTIBLE);
225 			if (!mddev->suspended)
226 				break;
227 			rcu_read_unlock();
228 			schedule();
229 			rcu_read_lock();
230 		}
231 		finish_wait(&mddev->sb_wait, &__wait);
232 	}
233 	atomic_inc(&mddev->active_io);
234 	rcu_read_unlock();
235 	rv = mddev->pers->make_request(q, bio);
236 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
237 		wake_up(&mddev->sb_wait);
238 
239 	return rv;
240 }
241 
242 static void mddev_suspend(mddev_t *mddev)
243 {
244 	BUG_ON(mddev->suspended);
245 	mddev->suspended = 1;
246 	synchronize_rcu();
247 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
248 	mddev->pers->quiesce(mddev, 1);
249 	md_unregister_thread(mddev->thread);
250 	mddev->thread = NULL;
251 	/* we now know that no code is executing in the personality module,
252 	 * except possibly the tail end of a ->bi_end_io function, but that
253 	 * is certain to complete before the module has a chance to get
254 	 * unloaded
255 	 */
256 }
257 
258 static void mddev_resume(mddev_t *mddev)
259 {
260 	mddev->suspended = 0;
261 	wake_up(&mddev->sb_wait);
262 	mddev->pers->quiesce(mddev, 0);
263 }
264 
265 
266 static inline mddev_t *mddev_get(mddev_t *mddev)
267 {
268 	atomic_inc(&mddev->active);
269 	return mddev;
270 }
271 
272 static void mddev_delayed_delete(struct work_struct *ws);
273 
274 static void mddev_put(mddev_t *mddev)
275 {
276 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
277 		return;
278 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
279 	    !mddev->hold_active) {
280 		list_del(&mddev->all_mddevs);
281 		if (mddev->gendisk) {
282 			/* we did a probe so need to clean up.
283 			 * Call schedule_work inside the spinlock
284 			 * so that flush_scheduled_work() after
285 			 * mddev_find will succeed in waiting for the
286 			 * work to be done.
287 			 */
288 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
289 			schedule_work(&mddev->del_work);
290 		} else
291 			kfree(mddev);
292 	}
293 	spin_unlock(&all_mddevs_lock);
294 }
295 
296 static mddev_t * mddev_find(dev_t unit)
297 {
298 	mddev_t *mddev, *new = NULL;
299 
300  retry:
301 	spin_lock(&all_mddevs_lock);
302 
303 	if (unit) {
304 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
305 			if (mddev->unit == unit) {
306 				mddev_get(mddev);
307 				spin_unlock(&all_mddevs_lock);
308 				kfree(new);
309 				return mddev;
310 			}
311 
312 		if (new) {
313 			list_add(&new->all_mddevs, &all_mddevs);
314 			spin_unlock(&all_mddevs_lock);
315 			new->hold_active = UNTIL_IOCTL;
316 			return new;
317 		}
318 	} else if (new) {
319 		/* find an unused unit number */
320 		static int next_minor = 512;
321 		int start = next_minor;
322 		int is_free = 0;
323 		int dev = 0;
324 		while (!is_free) {
325 			dev = MKDEV(MD_MAJOR, next_minor);
326 			next_minor++;
327 			if (next_minor > MINORMASK)
328 				next_minor = 0;
329 			if (next_minor == start) {
330 				/* Oh dear, all in use. */
331 				spin_unlock(&all_mddevs_lock);
332 				kfree(new);
333 				return NULL;
334 			}
335 
336 			is_free = 1;
337 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
338 				if (mddev->unit == dev) {
339 					is_free = 0;
340 					break;
341 				}
342 		}
343 		new->unit = dev;
344 		new->md_minor = MINOR(dev);
345 		new->hold_active = UNTIL_STOP;
346 		list_add(&new->all_mddevs, &all_mddevs);
347 		spin_unlock(&all_mddevs_lock);
348 		return new;
349 	}
350 	spin_unlock(&all_mddevs_lock);
351 
352 	new = kzalloc(sizeof(*new), GFP_KERNEL);
353 	if (!new)
354 		return NULL;
355 
356 	new->unit = unit;
357 	if (MAJOR(unit) == MD_MAJOR)
358 		new->md_minor = MINOR(unit);
359 	else
360 		new->md_minor = MINOR(unit) >> MdpMinorShift;
361 
362 	mutex_init(&new->reconfig_mutex);
363 	INIT_LIST_HEAD(&new->disks);
364 	INIT_LIST_HEAD(&new->all_mddevs);
365 	init_timer(&new->safemode_timer);
366 	atomic_set(&new->active, 1);
367 	atomic_set(&new->openers, 0);
368 	atomic_set(&new->active_io, 0);
369 	spin_lock_init(&new->write_lock);
370 	init_waitqueue_head(&new->sb_wait);
371 	init_waitqueue_head(&new->recovery_wait);
372 	new->reshape_position = MaxSector;
373 	new->resync_min = 0;
374 	new->resync_max = MaxSector;
375 	new->level = LEVEL_NONE;
376 
377 	goto retry;
378 }
379 
380 static inline int mddev_lock(mddev_t * mddev)
381 {
382 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
383 }
384 
385 static inline int mddev_is_locked(mddev_t *mddev)
386 {
387 	return mutex_is_locked(&mddev->reconfig_mutex);
388 }
389 
390 static inline int mddev_trylock(mddev_t * mddev)
391 {
392 	return mutex_trylock(&mddev->reconfig_mutex);
393 }
394 
395 static inline void mddev_unlock(mddev_t * mddev)
396 {
397 	mutex_unlock(&mddev->reconfig_mutex);
398 
399 	md_wakeup_thread(mddev->thread);
400 }
401 
402 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
403 {
404 	mdk_rdev_t *rdev;
405 
406 	list_for_each_entry(rdev, &mddev->disks, same_set)
407 		if (rdev->desc_nr == nr)
408 			return rdev;
409 
410 	return NULL;
411 }
412 
413 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
414 {
415 	mdk_rdev_t *rdev;
416 
417 	list_for_each_entry(rdev, &mddev->disks, same_set)
418 		if (rdev->bdev->bd_dev == dev)
419 			return rdev;
420 
421 	return NULL;
422 }
423 
424 static struct mdk_personality *find_pers(int level, char *clevel)
425 {
426 	struct mdk_personality *pers;
427 	list_for_each_entry(pers, &pers_list, list) {
428 		if (level != LEVEL_NONE && pers->level == level)
429 			return pers;
430 		if (strcmp(pers->name, clevel)==0)
431 			return pers;
432 	}
433 	return NULL;
434 }
435 
436 /* return the offset of the super block in 512byte sectors */
437 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
438 {
439 	sector_t num_sectors = bdev->bd_inode->i_size / 512;
440 	return MD_NEW_SIZE_SECTORS(num_sectors);
441 }
442 
443 static int alloc_disk_sb(mdk_rdev_t * rdev)
444 {
445 	if (rdev->sb_page)
446 		MD_BUG();
447 
448 	rdev->sb_page = alloc_page(GFP_KERNEL);
449 	if (!rdev->sb_page) {
450 		printk(KERN_ALERT "md: out of memory.\n");
451 		return -ENOMEM;
452 	}
453 
454 	return 0;
455 }
456 
457 static void free_disk_sb(mdk_rdev_t * rdev)
458 {
459 	if (rdev->sb_page) {
460 		put_page(rdev->sb_page);
461 		rdev->sb_loaded = 0;
462 		rdev->sb_page = NULL;
463 		rdev->sb_start = 0;
464 		rdev->sectors = 0;
465 	}
466 }
467 
468 
469 static void super_written(struct bio *bio, int error)
470 {
471 	mdk_rdev_t *rdev = bio->bi_private;
472 	mddev_t *mddev = rdev->mddev;
473 
474 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
475 		printk("md: super_written gets error=%d, uptodate=%d\n",
476 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
477 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
478 		md_error(mddev, rdev);
479 	}
480 
481 	if (atomic_dec_and_test(&mddev->pending_writes))
482 		wake_up(&mddev->sb_wait);
483 	bio_put(bio);
484 }
485 
486 static void super_written_barrier(struct bio *bio, int error)
487 {
488 	struct bio *bio2 = bio->bi_private;
489 	mdk_rdev_t *rdev = bio2->bi_private;
490 	mddev_t *mddev = rdev->mddev;
491 
492 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
493 	    error == -EOPNOTSUPP) {
494 		unsigned long flags;
495 		/* barriers don't appear to be supported :-( */
496 		set_bit(BarriersNotsupp, &rdev->flags);
497 		mddev->barriers_work = 0;
498 		spin_lock_irqsave(&mddev->write_lock, flags);
499 		bio2->bi_next = mddev->biolist;
500 		mddev->biolist = bio2;
501 		spin_unlock_irqrestore(&mddev->write_lock, flags);
502 		wake_up(&mddev->sb_wait);
503 		bio_put(bio);
504 	} else {
505 		bio_put(bio2);
506 		bio->bi_private = rdev;
507 		super_written(bio, error);
508 	}
509 }
510 
511 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
512 		   sector_t sector, int size, struct page *page)
513 {
514 	/* write first size bytes of page to sector of rdev
515 	 * Increment mddev->pending_writes before returning
516 	 * and decrement it on completion, waking up sb_wait
517 	 * if zero is reached.
518 	 * If an error occurred, call md_error
519 	 *
520 	 * As we might need to resubmit the request if BIO_RW_BARRIER
521 	 * causes ENOTSUPP, we allocate a spare bio...
522 	 */
523 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
524 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNCIO) | (1<<BIO_RW_UNPLUG);
525 
526 	bio->bi_bdev = rdev->bdev;
527 	bio->bi_sector = sector;
528 	bio_add_page(bio, page, size, 0);
529 	bio->bi_private = rdev;
530 	bio->bi_end_io = super_written;
531 	bio->bi_rw = rw;
532 
533 	atomic_inc(&mddev->pending_writes);
534 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
535 		struct bio *rbio;
536 		rw |= (1<<BIO_RW_BARRIER);
537 		rbio = bio_clone(bio, GFP_NOIO);
538 		rbio->bi_private = bio;
539 		rbio->bi_end_io = super_written_barrier;
540 		submit_bio(rw, rbio);
541 	} else
542 		submit_bio(rw, bio);
543 }
544 
545 void md_super_wait(mddev_t *mddev)
546 {
547 	/* wait for all superblock writes that were scheduled to complete.
548 	 * if any had to be retried (due to BARRIER problems), retry them
549 	 */
550 	DEFINE_WAIT(wq);
551 	for(;;) {
552 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
553 		if (atomic_read(&mddev->pending_writes)==0)
554 			break;
555 		while (mddev->biolist) {
556 			struct bio *bio;
557 			spin_lock_irq(&mddev->write_lock);
558 			bio = mddev->biolist;
559 			mddev->biolist = bio->bi_next ;
560 			bio->bi_next = NULL;
561 			spin_unlock_irq(&mddev->write_lock);
562 			submit_bio(bio->bi_rw, bio);
563 		}
564 		schedule();
565 	}
566 	finish_wait(&mddev->sb_wait, &wq);
567 }
568 
569 static void bi_complete(struct bio *bio, int error)
570 {
571 	complete((struct completion*)bio->bi_private);
572 }
573 
574 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
575 		   struct page *page, int rw)
576 {
577 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
578 	struct completion event;
579 	int ret;
580 
581 	rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
582 
583 	bio->bi_bdev = bdev;
584 	bio->bi_sector = sector;
585 	bio_add_page(bio, page, size, 0);
586 	init_completion(&event);
587 	bio->bi_private = &event;
588 	bio->bi_end_io = bi_complete;
589 	submit_bio(rw, bio);
590 	wait_for_completion(&event);
591 
592 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
593 	bio_put(bio);
594 	return ret;
595 }
596 EXPORT_SYMBOL_GPL(sync_page_io);
597 
598 static int read_disk_sb(mdk_rdev_t * rdev, int size)
599 {
600 	char b[BDEVNAME_SIZE];
601 	if (!rdev->sb_page) {
602 		MD_BUG();
603 		return -EINVAL;
604 	}
605 	if (rdev->sb_loaded)
606 		return 0;
607 
608 
609 	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
610 		goto fail;
611 	rdev->sb_loaded = 1;
612 	return 0;
613 
614 fail:
615 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
616 		bdevname(rdev->bdev,b));
617 	return -EINVAL;
618 }
619 
620 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
621 {
622 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
623 		sb1->set_uuid1 == sb2->set_uuid1 &&
624 		sb1->set_uuid2 == sb2->set_uuid2 &&
625 		sb1->set_uuid3 == sb2->set_uuid3;
626 }
627 
628 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
629 {
630 	int ret;
631 	mdp_super_t *tmp1, *tmp2;
632 
633 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
634 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
635 
636 	if (!tmp1 || !tmp2) {
637 		ret = 0;
638 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
639 		goto abort;
640 	}
641 
642 	*tmp1 = *sb1;
643 	*tmp2 = *sb2;
644 
645 	/*
646 	 * nr_disks is not constant
647 	 */
648 	tmp1->nr_disks = 0;
649 	tmp2->nr_disks = 0;
650 
651 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
652 abort:
653 	kfree(tmp1);
654 	kfree(tmp2);
655 	return ret;
656 }
657 
658 
659 static u32 md_csum_fold(u32 csum)
660 {
661 	csum = (csum & 0xffff) + (csum >> 16);
662 	return (csum & 0xffff) + (csum >> 16);
663 }
664 
665 static unsigned int calc_sb_csum(mdp_super_t * sb)
666 {
667 	u64 newcsum = 0;
668 	u32 *sb32 = (u32*)sb;
669 	int i;
670 	unsigned int disk_csum, csum;
671 
672 	disk_csum = sb->sb_csum;
673 	sb->sb_csum = 0;
674 
675 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
676 		newcsum += sb32[i];
677 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
678 
679 
680 #ifdef CONFIG_ALPHA
681 	/* This used to use csum_partial, which was wrong for several
682 	 * reasons including that different results are returned on
683 	 * different architectures.  It isn't critical that we get exactly
684 	 * the same return value as before (we always csum_fold before
685 	 * testing, and that removes any differences).  However as we
686 	 * know that csum_partial always returned a 16bit value on
687 	 * alphas, do a fold to maximise conformity to previous behaviour.
688 	 */
689 	sb->sb_csum = md_csum_fold(disk_csum);
690 #else
691 	sb->sb_csum = disk_csum;
692 #endif
693 	return csum;
694 }
695 
696 
697 /*
698  * Handle superblock details.
699  * We want to be able to handle multiple superblock formats
700  * so we have a common interface to them all, and an array of
701  * different handlers.
702  * We rely on user-space to write the initial superblock, and support
703  * reading and updating of superblocks.
704  * Interface methods are:
705  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
706  *      loads and validates a superblock on dev.
707  *      if refdev != NULL, compare superblocks on both devices
708  *    Return:
709  *      0 - dev has a superblock that is compatible with refdev
710  *      1 - dev has a superblock that is compatible and newer than refdev
711  *          so dev should be used as the refdev in future
712  *     -EINVAL superblock incompatible or invalid
713  *     -othererror e.g. -EIO
714  *
715  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
716  *      Verify that dev is acceptable into mddev.
717  *       The first time, mddev->raid_disks will be 0, and data from
718  *       dev should be merged in.  Subsequent calls check that dev
719  *       is new enough.  Return 0 or -EINVAL
720  *
721  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
722  *     Update the superblock for rdev with data in mddev
723  *     This does not write to disc.
724  *
725  */
726 
727 struct super_type  {
728 	char		    *name;
729 	struct module	    *owner;
730 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
731 					  int minor_version);
732 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
733 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
734 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
735 						sector_t num_sectors);
736 };
737 
738 /*
739  * Check that the given mddev has no bitmap.
740  *
741  * This function is called from the run method of all personalities that do not
742  * support bitmaps. It prints an error message and returns non-zero if mddev
743  * has a bitmap. Otherwise, it returns 0.
744  *
745  */
746 int md_check_no_bitmap(mddev_t *mddev)
747 {
748 	if (!mddev->bitmap_file && !mddev->bitmap_offset)
749 		return 0;
750 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
751 		mdname(mddev), mddev->pers->name);
752 	return 1;
753 }
754 EXPORT_SYMBOL(md_check_no_bitmap);
755 
756 /*
757  * load_super for 0.90.0
758  */
759 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
760 {
761 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
762 	mdp_super_t *sb;
763 	int ret;
764 
765 	/*
766 	 * Calculate the position of the superblock (512byte sectors),
767 	 * it's at the end of the disk.
768 	 *
769 	 * It also happens to be a multiple of 4Kb.
770 	 */
771 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
772 
773 	ret = read_disk_sb(rdev, MD_SB_BYTES);
774 	if (ret) return ret;
775 
776 	ret = -EINVAL;
777 
778 	bdevname(rdev->bdev, b);
779 	sb = (mdp_super_t*)page_address(rdev->sb_page);
780 
781 	if (sb->md_magic != MD_SB_MAGIC) {
782 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
783 		       b);
784 		goto abort;
785 	}
786 
787 	if (sb->major_version != 0 ||
788 	    sb->minor_version < 90 ||
789 	    sb->minor_version > 91) {
790 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
791 			sb->major_version, sb->minor_version,
792 			b);
793 		goto abort;
794 	}
795 
796 	if (sb->raid_disks <= 0)
797 		goto abort;
798 
799 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
800 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
801 			b);
802 		goto abort;
803 	}
804 
805 	rdev->preferred_minor = sb->md_minor;
806 	rdev->data_offset = 0;
807 	rdev->sb_size = MD_SB_BYTES;
808 
809 	if (sb->level == LEVEL_MULTIPATH)
810 		rdev->desc_nr = -1;
811 	else
812 		rdev->desc_nr = sb->this_disk.number;
813 
814 	if (!refdev) {
815 		ret = 1;
816 	} else {
817 		__u64 ev1, ev2;
818 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
819 		if (!uuid_equal(refsb, sb)) {
820 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
821 				b, bdevname(refdev->bdev,b2));
822 			goto abort;
823 		}
824 		if (!sb_equal(refsb, sb)) {
825 			printk(KERN_WARNING "md: %s has same UUID"
826 			       " but different superblock to %s\n",
827 			       b, bdevname(refdev->bdev, b2));
828 			goto abort;
829 		}
830 		ev1 = md_event(sb);
831 		ev2 = md_event(refsb);
832 		if (ev1 > ev2)
833 			ret = 1;
834 		else
835 			ret = 0;
836 	}
837 	rdev->sectors = rdev->sb_start;
838 
839 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
840 		/* "this cannot possibly happen" ... */
841 		ret = -EINVAL;
842 
843  abort:
844 	return ret;
845 }
846 
847 /*
848  * validate_super for 0.90.0
849  */
850 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
851 {
852 	mdp_disk_t *desc;
853 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
854 	__u64 ev1 = md_event(sb);
855 
856 	rdev->raid_disk = -1;
857 	clear_bit(Faulty, &rdev->flags);
858 	clear_bit(In_sync, &rdev->flags);
859 	clear_bit(WriteMostly, &rdev->flags);
860 	clear_bit(BarriersNotsupp, &rdev->flags);
861 
862 	if (mddev->raid_disks == 0) {
863 		mddev->major_version = 0;
864 		mddev->minor_version = sb->minor_version;
865 		mddev->patch_version = sb->patch_version;
866 		mddev->external = 0;
867 		mddev->chunk_sectors = sb->chunk_size >> 9;
868 		mddev->ctime = sb->ctime;
869 		mddev->utime = sb->utime;
870 		mddev->level = sb->level;
871 		mddev->clevel[0] = 0;
872 		mddev->layout = sb->layout;
873 		mddev->raid_disks = sb->raid_disks;
874 		mddev->dev_sectors = sb->size * 2;
875 		mddev->events = ev1;
876 		mddev->bitmap_offset = 0;
877 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
878 
879 		if (mddev->minor_version >= 91) {
880 			mddev->reshape_position = sb->reshape_position;
881 			mddev->delta_disks = sb->delta_disks;
882 			mddev->new_level = sb->new_level;
883 			mddev->new_layout = sb->new_layout;
884 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
885 		} else {
886 			mddev->reshape_position = MaxSector;
887 			mddev->delta_disks = 0;
888 			mddev->new_level = mddev->level;
889 			mddev->new_layout = mddev->layout;
890 			mddev->new_chunk_sectors = mddev->chunk_sectors;
891 		}
892 
893 		if (sb->state & (1<<MD_SB_CLEAN))
894 			mddev->recovery_cp = MaxSector;
895 		else {
896 			if (sb->events_hi == sb->cp_events_hi &&
897 				sb->events_lo == sb->cp_events_lo) {
898 				mddev->recovery_cp = sb->recovery_cp;
899 			} else
900 				mddev->recovery_cp = 0;
901 		}
902 
903 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
904 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
905 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
906 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
907 
908 		mddev->max_disks = MD_SB_DISKS;
909 
910 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
911 		    mddev->bitmap_file == NULL)
912 			mddev->bitmap_offset = mddev->default_bitmap_offset;
913 
914 	} else if (mddev->pers == NULL) {
915 		/* Insist on good event counter while assembling */
916 		++ev1;
917 		if (ev1 < mddev->events)
918 			return -EINVAL;
919 	} else if (mddev->bitmap) {
920 		/* if adding to array with a bitmap, then we can accept an
921 		 * older device ... but not too old.
922 		 */
923 		if (ev1 < mddev->bitmap->events_cleared)
924 			return 0;
925 	} else {
926 		if (ev1 < mddev->events)
927 			/* just a hot-add of a new device, leave raid_disk at -1 */
928 			return 0;
929 	}
930 
931 	if (mddev->level != LEVEL_MULTIPATH) {
932 		desc = sb->disks + rdev->desc_nr;
933 
934 		if (desc->state & (1<<MD_DISK_FAULTY))
935 			set_bit(Faulty, &rdev->flags);
936 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
937 			    desc->raid_disk < mddev->raid_disks */) {
938 			set_bit(In_sync, &rdev->flags);
939 			rdev->raid_disk = desc->raid_disk;
940 		}
941 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
942 			set_bit(WriteMostly, &rdev->flags);
943 	} else /* MULTIPATH are always insync */
944 		set_bit(In_sync, &rdev->flags);
945 	return 0;
946 }
947 
948 /*
949  * sync_super for 0.90.0
950  */
951 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
952 {
953 	mdp_super_t *sb;
954 	mdk_rdev_t *rdev2;
955 	int next_spare = mddev->raid_disks;
956 
957 
958 	/* make rdev->sb match mddev data..
959 	 *
960 	 * 1/ zero out disks
961 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
962 	 * 3/ any empty disks < next_spare become removed
963 	 *
964 	 * disks[0] gets initialised to REMOVED because
965 	 * we cannot be sure from other fields if it has
966 	 * been initialised or not.
967 	 */
968 	int i;
969 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
970 
971 	rdev->sb_size = MD_SB_BYTES;
972 
973 	sb = (mdp_super_t*)page_address(rdev->sb_page);
974 
975 	memset(sb, 0, sizeof(*sb));
976 
977 	sb->md_magic = MD_SB_MAGIC;
978 	sb->major_version = mddev->major_version;
979 	sb->patch_version = mddev->patch_version;
980 	sb->gvalid_words  = 0; /* ignored */
981 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
982 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
983 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
984 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
985 
986 	sb->ctime = mddev->ctime;
987 	sb->level = mddev->level;
988 	sb->size = mddev->dev_sectors / 2;
989 	sb->raid_disks = mddev->raid_disks;
990 	sb->md_minor = mddev->md_minor;
991 	sb->not_persistent = 0;
992 	sb->utime = mddev->utime;
993 	sb->state = 0;
994 	sb->events_hi = (mddev->events>>32);
995 	sb->events_lo = (u32)mddev->events;
996 
997 	if (mddev->reshape_position == MaxSector)
998 		sb->minor_version = 90;
999 	else {
1000 		sb->minor_version = 91;
1001 		sb->reshape_position = mddev->reshape_position;
1002 		sb->new_level = mddev->new_level;
1003 		sb->delta_disks = mddev->delta_disks;
1004 		sb->new_layout = mddev->new_layout;
1005 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1006 	}
1007 	mddev->minor_version = sb->minor_version;
1008 	if (mddev->in_sync)
1009 	{
1010 		sb->recovery_cp = mddev->recovery_cp;
1011 		sb->cp_events_hi = (mddev->events>>32);
1012 		sb->cp_events_lo = (u32)mddev->events;
1013 		if (mddev->recovery_cp == MaxSector)
1014 			sb->state = (1<< MD_SB_CLEAN);
1015 	} else
1016 		sb->recovery_cp = 0;
1017 
1018 	sb->layout = mddev->layout;
1019 	sb->chunk_size = mddev->chunk_sectors << 9;
1020 
1021 	if (mddev->bitmap && mddev->bitmap_file == NULL)
1022 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1023 
1024 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1025 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1026 		mdp_disk_t *d;
1027 		int desc_nr;
1028 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
1029 		    && !test_bit(Faulty, &rdev2->flags))
1030 			desc_nr = rdev2->raid_disk;
1031 		else
1032 			desc_nr = next_spare++;
1033 		rdev2->desc_nr = desc_nr;
1034 		d = &sb->disks[rdev2->desc_nr];
1035 		nr_disks++;
1036 		d->number = rdev2->desc_nr;
1037 		d->major = MAJOR(rdev2->bdev->bd_dev);
1038 		d->minor = MINOR(rdev2->bdev->bd_dev);
1039 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
1040 		    && !test_bit(Faulty, &rdev2->flags))
1041 			d->raid_disk = rdev2->raid_disk;
1042 		else
1043 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1044 		if (test_bit(Faulty, &rdev2->flags))
1045 			d->state = (1<<MD_DISK_FAULTY);
1046 		else if (test_bit(In_sync, &rdev2->flags)) {
1047 			d->state = (1<<MD_DISK_ACTIVE);
1048 			d->state |= (1<<MD_DISK_SYNC);
1049 			active++;
1050 			working++;
1051 		} else {
1052 			d->state = 0;
1053 			spare++;
1054 			working++;
1055 		}
1056 		if (test_bit(WriteMostly, &rdev2->flags))
1057 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1058 	}
1059 	/* now set the "removed" and "faulty" bits on any missing devices */
1060 	for (i=0 ; i < mddev->raid_disks ; i++) {
1061 		mdp_disk_t *d = &sb->disks[i];
1062 		if (d->state == 0 && d->number == 0) {
1063 			d->number = i;
1064 			d->raid_disk = i;
1065 			d->state = (1<<MD_DISK_REMOVED);
1066 			d->state |= (1<<MD_DISK_FAULTY);
1067 			failed++;
1068 		}
1069 	}
1070 	sb->nr_disks = nr_disks;
1071 	sb->active_disks = active;
1072 	sb->working_disks = working;
1073 	sb->failed_disks = failed;
1074 	sb->spare_disks = spare;
1075 
1076 	sb->this_disk = sb->disks[rdev->desc_nr];
1077 	sb->sb_csum = calc_sb_csum(sb);
1078 }
1079 
1080 /*
1081  * rdev_size_change for 0.90.0
1082  */
1083 static unsigned long long
1084 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1085 {
1086 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1087 		return 0; /* component must fit device */
1088 	if (rdev->mddev->bitmap_offset)
1089 		return 0; /* can't move bitmap */
1090 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1091 	if (!num_sectors || num_sectors > rdev->sb_start)
1092 		num_sectors = rdev->sb_start;
1093 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1094 		       rdev->sb_page);
1095 	md_super_wait(rdev->mddev);
1096 	return num_sectors / 2; /* kB for sysfs */
1097 }
1098 
1099 
1100 /*
1101  * version 1 superblock
1102  */
1103 
1104 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1105 {
1106 	__le32 disk_csum;
1107 	u32 csum;
1108 	unsigned long long newcsum;
1109 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1110 	__le32 *isuper = (__le32*)sb;
1111 	int i;
1112 
1113 	disk_csum = sb->sb_csum;
1114 	sb->sb_csum = 0;
1115 	newcsum = 0;
1116 	for (i=0; size>=4; size -= 4 )
1117 		newcsum += le32_to_cpu(*isuper++);
1118 
1119 	if (size == 2)
1120 		newcsum += le16_to_cpu(*(__le16*) isuper);
1121 
1122 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1123 	sb->sb_csum = disk_csum;
1124 	return cpu_to_le32(csum);
1125 }
1126 
1127 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1128 {
1129 	struct mdp_superblock_1 *sb;
1130 	int ret;
1131 	sector_t sb_start;
1132 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1133 	int bmask;
1134 
1135 	/*
1136 	 * Calculate the position of the superblock in 512byte sectors.
1137 	 * It is always aligned to a 4K boundary and
1138 	 * depeding on minor_version, it can be:
1139 	 * 0: At least 8K, but less than 12K, from end of device
1140 	 * 1: At start of device
1141 	 * 2: 4K from start of device.
1142 	 */
1143 	switch(minor_version) {
1144 	case 0:
1145 		sb_start = rdev->bdev->bd_inode->i_size >> 9;
1146 		sb_start -= 8*2;
1147 		sb_start &= ~(sector_t)(4*2-1);
1148 		break;
1149 	case 1:
1150 		sb_start = 0;
1151 		break;
1152 	case 2:
1153 		sb_start = 8;
1154 		break;
1155 	default:
1156 		return -EINVAL;
1157 	}
1158 	rdev->sb_start = sb_start;
1159 
1160 	/* superblock is rarely larger than 1K, but it can be larger,
1161 	 * and it is safe to read 4k, so we do that
1162 	 */
1163 	ret = read_disk_sb(rdev, 4096);
1164 	if (ret) return ret;
1165 
1166 
1167 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1168 
1169 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1170 	    sb->major_version != cpu_to_le32(1) ||
1171 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1172 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1173 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1174 		return -EINVAL;
1175 
1176 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1177 		printk("md: invalid superblock checksum on %s\n",
1178 			bdevname(rdev->bdev,b));
1179 		return -EINVAL;
1180 	}
1181 	if (le64_to_cpu(sb->data_size) < 10) {
1182 		printk("md: data_size too small on %s\n",
1183 		       bdevname(rdev->bdev,b));
1184 		return -EINVAL;
1185 	}
1186 
1187 	rdev->preferred_minor = 0xffff;
1188 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1189 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1190 
1191 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1192 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1193 	if (rdev->sb_size & bmask)
1194 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1195 
1196 	if (minor_version
1197 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1198 		return -EINVAL;
1199 
1200 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1201 		rdev->desc_nr = -1;
1202 	else
1203 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1204 
1205 	if (!refdev) {
1206 		ret = 1;
1207 	} else {
1208 		__u64 ev1, ev2;
1209 		struct mdp_superblock_1 *refsb =
1210 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1211 
1212 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1213 		    sb->level != refsb->level ||
1214 		    sb->layout != refsb->layout ||
1215 		    sb->chunksize != refsb->chunksize) {
1216 			printk(KERN_WARNING "md: %s has strangely different"
1217 				" superblock to %s\n",
1218 				bdevname(rdev->bdev,b),
1219 				bdevname(refdev->bdev,b2));
1220 			return -EINVAL;
1221 		}
1222 		ev1 = le64_to_cpu(sb->events);
1223 		ev2 = le64_to_cpu(refsb->events);
1224 
1225 		if (ev1 > ev2)
1226 			ret = 1;
1227 		else
1228 			ret = 0;
1229 	}
1230 	if (minor_version)
1231 		rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
1232 			le64_to_cpu(sb->data_offset);
1233 	else
1234 		rdev->sectors = rdev->sb_start;
1235 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1236 		return -EINVAL;
1237 	rdev->sectors = le64_to_cpu(sb->data_size);
1238 	if (le64_to_cpu(sb->size) > rdev->sectors)
1239 		return -EINVAL;
1240 	return ret;
1241 }
1242 
1243 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1244 {
1245 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1246 	__u64 ev1 = le64_to_cpu(sb->events);
1247 
1248 	rdev->raid_disk = -1;
1249 	clear_bit(Faulty, &rdev->flags);
1250 	clear_bit(In_sync, &rdev->flags);
1251 	clear_bit(WriteMostly, &rdev->flags);
1252 	clear_bit(BarriersNotsupp, &rdev->flags);
1253 
1254 	if (mddev->raid_disks == 0) {
1255 		mddev->major_version = 1;
1256 		mddev->patch_version = 0;
1257 		mddev->external = 0;
1258 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1259 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1260 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1261 		mddev->level = le32_to_cpu(sb->level);
1262 		mddev->clevel[0] = 0;
1263 		mddev->layout = le32_to_cpu(sb->layout);
1264 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1265 		mddev->dev_sectors = le64_to_cpu(sb->size);
1266 		mddev->events = ev1;
1267 		mddev->bitmap_offset = 0;
1268 		mddev->default_bitmap_offset = 1024 >> 9;
1269 
1270 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1271 		memcpy(mddev->uuid, sb->set_uuid, 16);
1272 
1273 		mddev->max_disks =  (4096-256)/2;
1274 
1275 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1276 		    mddev->bitmap_file == NULL )
1277 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1278 
1279 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1280 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1281 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1282 			mddev->new_level = le32_to_cpu(sb->new_level);
1283 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1284 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1285 		} else {
1286 			mddev->reshape_position = MaxSector;
1287 			mddev->delta_disks = 0;
1288 			mddev->new_level = mddev->level;
1289 			mddev->new_layout = mddev->layout;
1290 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1291 		}
1292 
1293 	} else if (mddev->pers == NULL) {
1294 		/* Insist of good event counter while assembling */
1295 		++ev1;
1296 		if (ev1 < mddev->events)
1297 			return -EINVAL;
1298 	} else if (mddev->bitmap) {
1299 		/* If adding to array with a bitmap, then we can accept an
1300 		 * older device, but not too old.
1301 		 */
1302 		if (ev1 < mddev->bitmap->events_cleared)
1303 			return 0;
1304 	} else {
1305 		if (ev1 < mddev->events)
1306 			/* just a hot-add of a new device, leave raid_disk at -1 */
1307 			return 0;
1308 	}
1309 	if (mddev->level != LEVEL_MULTIPATH) {
1310 		int role;
1311 		if (rdev->desc_nr < 0 ||
1312 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1313 			role = 0xffff;
1314 			rdev->desc_nr = -1;
1315 		} else
1316 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1317 		switch(role) {
1318 		case 0xffff: /* spare */
1319 			break;
1320 		case 0xfffe: /* faulty */
1321 			set_bit(Faulty, &rdev->flags);
1322 			break;
1323 		default:
1324 			if ((le32_to_cpu(sb->feature_map) &
1325 			     MD_FEATURE_RECOVERY_OFFSET))
1326 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1327 			else
1328 				set_bit(In_sync, &rdev->flags);
1329 			rdev->raid_disk = role;
1330 			break;
1331 		}
1332 		if (sb->devflags & WriteMostly1)
1333 			set_bit(WriteMostly, &rdev->flags);
1334 	} else /* MULTIPATH are always insync */
1335 		set_bit(In_sync, &rdev->flags);
1336 
1337 	return 0;
1338 }
1339 
1340 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1341 {
1342 	struct mdp_superblock_1 *sb;
1343 	mdk_rdev_t *rdev2;
1344 	int max_dev, i;
1345 	/* make rdev->sb match mddev and rdev data. */
1346 
1347 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1348 
1349 	sb->feature_map = 0;
1350 	sb->pad0 = 0;
1351 	sb->recovery_offset = cpu_to_le64(0);
1352 	memset(sb->pad1, 0, sizeof(sb->pad1));
1353 	memset(sb->pad2, 0, sizeof(sb->pad2));
1354 	memset(sb->pad3, 0, sizeof(sb->pad3));
1355 
1356 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1357 	sb->events = cpu_to_le64(mddev->events);
1358 	if (mddev->in_sync)
1359 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1360 	else
1361 		sb->resync_offset = cpu_to_le64(0);
1362 
1363 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1364 
1365 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1366 	sb->size = cpu_to_le64(mddev->dev_sectors);
1367 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1368 	sb->level = cpu_to_le32(mddev->level);
1369 	sb->layout = cpu_to_le32(mddev->layout);
1370 
1371 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1372 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1373 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1374 	}
1375 
1376 	if (rdev->raid_disk >= 0 &&
1377 	    !test_bit(In_sync, &rdev->flags)) {
1378 		if (mddev->curr_resync_completed > rdev->recovery_offset)
1379 			rdev->recovery_offset = mddev->curr_resync_completed;
1380 		if (rdev->recovery_offset > 0) {
1381 			sb->feature_map |=
1382 				cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1383 			sb->recovery_offset =
1384 				cpu_to_le64(rdev->recovery_offset);
1385 		}
1386 	}
1387 
1388 	if (mddev->reshape_position != MaxSector) {
1389 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1390 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1391 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1392 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1393 		sb->new_level = cpu_to_le32(mddev->new_level);
1394 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1395 	}
1396 
1397 	max_dev = 0;
1398 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1399 		if (rdev2->desc_nr+1 > max_dev)
1400 			max_dev = rdev2->desc_nr+1;
1401 
1402 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1403 		int bmask;
1404 		sb->max_dev = cpu_to_le32(max_dev);
1405 		rdev->sb_size = max_dev * 2 + 256;
1406 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1407 		if (rdev->sb_size & bmask)
1408 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1409 	}
1410 	for (i=0; i<max_dev;i++)
1411 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1412 
1413 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1414 		i = rdev2->desc_nr;
1415 		if (test_bit(Faulty, &rdev2->flags))
1416 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1417 		else if (test_bit(In_sync, &rdev2->flags))
1418 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1419 		else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
1420 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1421 		else
1422 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1423 	}
1424 
1425 	sb->sb_csum = calc_sb_1_csum(sb);
1426 }
1427 
1428 static unsigned long long
1429 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1430 {
1431 	struct mdp_superblock_1 *sb;
1432 	sector_t max_sectors;
1433 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1434 		return 0; /* component must fit device */
1435 	if (rdev->sb_start < rdev->data_offset) {
1436 		/* minor versions 1 and 2; superblock before data */
1437 		max_sectors = rdev->bdev->bd_inode->i_size >> 9;
1438 		max_sectors -= rdev->data_offset;
1439 		if (!num_sectors || num_sectors > max_sectors)
1440 			num_sectors = max_sectors;
1441 	} else if (rdev->mddev->bitmap_offset) {
1442 		/* minor version 0 with bitmap we can't move */
1443 		return 0;
1444 	} else {
1445 		/* minor version 0; superblock after data */
1446 		sector_t sb_start;
1447 		sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
1448 		sb_start &= ~(sector_t)(4*2 - 1);
1449 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1450 		if (!num_sectors || num_sectors > max_sectors)
1451 			num_sectors = max_sectors;
1452 		rdev->sb_start = sb_start;
1453 	}
1454 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1455 	sb->data_size = cpu_to_le64(num_sectors);
1456 	sb->super_offset = rdev->sb_start;
1457 	sb->sb_csum = calc_sb_1_csum(sb);
1458 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1459 		       rdev->sb_page);
1460 	md_super_wait(rdev->mddev);
1461 	return num_sectors / 2; /* kB for sysfs */
1462 }
1463 
1464 static struct super_type super_types[] = {
1465 	[0] = {
1466 		.name	= "0.90.0",
1467 		.owner	= THIS_MODULE,
1468 		.load_super	    = super_90_load,
1469 		.validate_super	    = super_90_validate,
1470 		.sync_super	    = super_90_sync,
1471 		.rdev_size_change   = super_90_rdev_size_change,
1472 	},
1473 	[1] = {
1474 		.name	= "md-1",
1475 		.owner	= THIS_MODULE,
1476 		.load_super	    = super_1_load,
1477 		.validate_super	    = super_1_validate,
1478 		.sync_super	    = super_1_sync,
1479 		.rdev_size_change   = super_1_rdev_size_change,
1480 	},
1481 };
1482 
1483 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1484 {
1485 	mdk_rdev_t *rdev, *rdev2;
1486 
1487 	rcu_read_lock();
1488 	rdev_for_each_rcu(rdev, mddev1)
1489 		rdev_for_each_rcu(rdev2, mddev2)
1490 			if (rdev->bdev->bd_contains ==
1491 			    rdev2->bdev->bd_contains) {
1492 				rcu_read_unlock();
1493 				return 1;
1494 			}
1495 	rcu_read_unlock();
1496 	return 0;
1497 }
1498 
1499 static LIST_HEAD(pending_raid_disks);
1500 
1501 /*
1502  * Try to register data integrity profile for an mddev
1503  *
1504  * This is called when an array is started and after a disk has been kicked
1505  * from the array. It only succeeds if all working and active component devices
1506  * are integrity capable with matching profiles.
1507  */
1508 int md_integrity_register(mddev_t *mddev)
1509 {
1510 	mdk_rdev_t *rdev, *reference = NULL;
1511 
1512 	if (list_empty(&mddev->disks))
1513 		return 0; /* nothing to do */
1514 	if (blk_get_integrity(mddev->gendisk))
1515 		return 0; /* already registered */
1516 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1517 		/* skip spares and non-functional disks */
1518 		if (test_bit(Faulty, &rdev->flags))
1519 			continue;
1520 		if (rdev->raid_disk < 0)
1521 			continue;
1522 		/*
1523 		 * If at least one rdev is not integrity capable, we can not
1524 		 * enable data integrity for the md device.
1525 		 */
1526 		if (!bdev_get_integrity(rdev->bdev))
1527 			return -EINVAL;
1528 		if (!reference) {
1529 			/* Use the first rdev as the reference */
1530 			reference = rdev;
1531 			continue;
1532 		}
1533 		/* does this rdev's profile match the reference profile? */
1534 		if (blk_integrity_compare(reference->bdev->bd_disk,
1535 				rdev->bdev->bd_disk) < 0)
1536 			return -EINVAL;
1537 	}
1538 	/*
1539 	 * All component devices are integrity capable and have matching
1540 	 * profiles, register the common profile for the md device.
1541 	 */
1542 	if (blk_integrity_register(mddev->gendisk,
1543 			bdev_get_integrity(reference->bdev)) != 0) {
1544 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1545 			mdname(mddev));
1546 		return -EINVAL;
1547 	}
1548 	printk(KERN_NOTICE "md: data integrity on %s enabled\n",
1549 		mdname(mddev));
1550 	return 0;
1551 }
1552 EXPORT_SYMBOL(md_integrity_register);
1553 
1554 /* Disable data integrity if non-capable/non-matching disk is being added */
1555 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1556 {
1557 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1558 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1559 
1560 	if (!bi_mddev) /* nothing to do */
1561 		return;
1562 	if (rdev->raid_disk < 0) /* skip spares */
1563 		return;
1564 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1565 					     rdev->bdev->bd_disk) >= 0)
1566 		return;
1567 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1568 	blk_integrity_unregister(mddev->gendisk);
1569 }
1570 EXPORT_SYMBOL(md_integrity_add_rdev);
1571 
1572 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1573 {
1574 	char b[BDEVNAME_SIZE];
1575 	struct kobject *ko;
1576 	char *s;
1577 	int err;
1578 
1579 	if (rdev->mddev) {
1580 		MD_BUG();
1581 		return -EINVAL;
1582 	}
1583 
1584 	/* prevent duplicates */
1585 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1586 		return -EEXIST;
1587 
1588 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
1589 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
1590 			rdev->sectors < mddev->dev_sectors)) {
1591 		if (mddev->pers) {
1592 			/* Cannot change size, so fail
1593 			 * If mddev->level <= 0, then we don't care
1594 			 * about aligning sizes (e.g. linear)
1595 			 */
1596 			if (mddev->level > 0)
1597 				return -ENOSPC;
1598 		} else
1599 			mddev->dev_sectors = rdev->sectors;
1600 	}
1601 
1602 	/* Verify rdev->desc_nr is unique.
1603 	 * If it is -1, assign a free number, else
1604 	 * check number is not in use
1605 	 */
1606 	if (rdev->desc_nr < 0) {
1607 		int choice = 0;
1608 		if (mddev->pers) choice = mddev->raid_disks;
1609 		while (find_rdev_nr(mddev, choice))
1610 			choice++;
1611 		rdev->desc_nr = choice;
1612 	} else {
1613 		if (find_rdev_nr(mddev, rdev->desc_nr))
1614 			return -EBUSY;
1615 	}
1616 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1617 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1618 		       mdname(mddev), mddev->max_disks);
1619 		return -EBUSY;
1620 	}
1621 	bdevname(rdev->bdev,b);
1622 	while ( (s=strchr(b, '/')) != NULL)
1623 		*s = '!';
1624 
1625 	rdev->mddev = mddev;
1626 	printk(KERN_INFO "md: bind<%s>\n", b);
1627 
1628 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1629 		goto fail;
1630 
1631 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1632 	if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
1633 		kobject_del(&rdev->kobj);
1634 		goto fail;
1635 	}
1636 	rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, "state");
1637 
1638 	list_add_rcu(&rdev->same_set, &mddev->disks);
1639 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1640 
1641 	/* May as well allow recovery to be retried once */
1642 	mddev->recovery_disabled = 0;
1643 
1644 	return 0;
1645 
1646  fail:
1647 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1648 	       b, mdname(mddev));
1649 	return err;
1650 }
1651 
1652 static void md_delayed_delete(struct work_struct *ws)
1653 {
1654 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1655 	kobject_del(&rdev->kobj);
1656 	kobject_put(&rdev->kobj);
1657 }
1658 
1659 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1660 {
1661 	char b[BDEVNAME_SIZE];
1662 	if (!rdev->mddev) {
1663 		MD_BUG();
1664 		return;
1665 	}
1666 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1667 	list_del_rcu(&rdev->same_set);
1668 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1669 	rdev->mddev = NULL;
1670 	sysfs_remove_link(&rdev->kobj, "block");
1671 	sysfs_put(rdev->sysfs_state);
1672 	rdev->sysfs_state = NULL;
1673 	/* We need to delay this, otherwise we can deadlock when
1674 	 * writing to 'remove' to "dev/state".  We also need
1675 	 * to delay it due to rcu usage.
1676 	 */
1677 	synchronize_rcu();
1678 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1679 	kobject_get(&rdev->kobj);
1680 	schedule_work(&rdev->del_work);
1681 }
1682 
1683 /*
1684  * prevent the device from being mounted, repartitioned or
1685  * otherwise reused by a RAID array (or any other kernel
1686  * subsystem), by bd_claiming the device.
1687  */
1688 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1689 {
1690 	int err = 0;
1691 	struct block_device *bdev;
1692 	char b[BDEVNAME_SIZE];
1693 
1694 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1695 	if (IS_ERR(bdev)) {
1696 		printk(KERN_ERR "md: could not open %s.\n",
1697 			__bdevname(dev, b));
1698 		return PTR_ERR(bdev);
1699 	}
1700 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1701 	if (err) {
1702 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1703 			bdevname(bdev, b));
1704 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1705 		return err;
1706 	}
1707 	if (!shared)
1708 		set_bit(AllReserved, &rdev->flags);
1709 	rdev->bdev = bdev;
1710 	return err;
1711 }
1712 
1713 static void unlock_rdev(mdk_rdev_t *rdev)
1714 {
1715 	struct block_device *bdev = rdev->bdev;
1716 	rdev->bdev = NULL;
1717 	if (!bdev)
1718 		MD_BUG();
1719 	bd_release(bdev);
1720 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1721 }
1722 
1723 void md_autodetect_dev(dev_t dev);
1724 
1725 static void export_rdev(mdk_rdev_t * rdev)
1726 {
1727 	char b[BDEVNAME_SIZE];
1728 	printk(KERN_INFO "md: export_rdev(%s)\n",
1729 		bdevname(rdev->bdev,b));
1730 	if (rdev->mddev)
1731 		MD_BUG();
1732 	free_disk_sb(rdev);
1733 #ifndef MODULE
1734 	if (test_bit(AutoDetected, &rdev->flags))
1735 		md_autodetect_dev(rdev->bdev->bd_dev);
1736 #endif
1737 	unlock_rdev(rdev);
1738 	kobject_put(&rdev->kobj);
1739 }
1740 
1741 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1742 {
1743 	unbind_rdev_from_array(rdev);
1744 	export_rdev(rdev);
1745 }
1746 
1747 static void export_array(mddev_t *mddev)
1748 {
1749 	mdk_rdev_t *rdev, *tmp;
1750 
1751 	rdev_for_each(rdev, tmp, mddev) {
1752 		if (!rdev->mddev) {
1753 			MD_BUG();
1754 			continue;
1755 		}
1756 		kick_rdev_from_array(rdev);
1757 	}
1758 	if (!list_empty(&mddev->disks))
1759 		MD_BUG();
1760 	mddev->raid_disks = 0;
1761 	mddev->major_version = 0;
1762 }
1763 
1764 static void print_desc(mdp_disk_t *desc)
1765 {
1766 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1767 		desc->major,desc->minor,desc->raid_disk,desc->state);
1768 }
1769 
1770 static void print_sb_90(mdp_super_t *sb)
1771 {
1772 	int i;
1773 
1774 	printk(KERN_INFO
1775 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1776 		sb->major_version, sb->minor_version, sb->patch_version,
1777 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1778 		sb->ctime);
1779 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1780 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1781 		sb->md_minor, sb->layout, sb->chunk_size);
1782 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1783 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1784 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1785 		sb->failed_disks, sb->spare_disks,
1786 		sb->sb_csum, (unsigned long)sb->events_lo);
1787 
1788 	printk(KERN_INFO);
1789 	for (i = 0; i < MD_SB_DISKS; i++) {
1790 		mdp_disk_t *desc;
1791 
1792 		desc = sb->disks + i;
1793 		if (desc->number || desc->major || desc->minor ||
1794 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1795 			printk("     D %2d: ", i);
1796 			print_desc(desc);
1797 		}
1798 	}
1799 	printk(KERN_INFO "md:     THIS: ");
1800 	print_desc(&sb->this_disk);
1801 }
1802 
1803 static void print_sb_1(struct mdp_superblock_1 *sb)
1804 {
1805 	__u8 *uuid;
1806 
1807 	uuid = sb->set_uuid;
1808 	printk(KERN_INFO
1809 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%02x%02x%02x%02x"
1810 	       ":%02x%02x:%02x%02x:%02x%02x:%02x%02x%02x%02x%02x%02x>\n"
1811 	       "md:    Name: \"%s\" CT:%llu\n",
1812 		le32_to_cpu(sb->major_version),
1813 		le32_to_cpu(sb->feature_map),
1814 		uuid[0], uuid[1], uuid[2], uuid[3],
1815 		uuid[4], uuid[5], uuid[6], uuid[7],
1816 		uuid[8], uuid[9], uuid[10], uuid[11],
1817 		uuid[12], uuid[13], uuid[14], uuid[15],
1818 		sb->set_name,
1819 		(unsigned long long)le64_to_cpu(sb->ctime)
1820 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
1821 
1822 	uuid = sb->device_uuid;
1823 	printk(KERN_INFO
1824 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
1825 			" RO:%llu\n"
1826 	       "md:     Dev:%08x UUID: %02x%02x%02x%02x:%02x%02x:%02x%02x:%02x%02x"
1827 	                ":%02x%02x%02x%02x%02x%02x\n"
1828 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
1829 	       "md:         (MaxDev:%u) \n",
1830 		le32_to_cpu(sb->level),
1831 		(unsigned long long)le64_to_cpu(sb->size),
1832 		le32_to_cpu(sb->raid_disks),
1833 		le32_to_cpu(sb->layout),
1834 		le32_to_cpu(sb->chunksize),
1835 		(unsigned long long)le64_to_cpu(sb->data_offset),
1836 		(unsigned long long)le64_to_cpu(sb->data_size),
1837 		(unsigned long long)le64_to_cpu(sb->super_offset),
1838 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
1839 		le32_to_cpu(sb->dev_number),
1840 		uuid[0], uuid[1], uuid[2], uuid[3],
1841 		uuid[4], uuid[5], uuid[6], uuid[7],
1842 		uuid[8], uuid[9], uuid[10], uuid[11],
1843 		uuid[12], uuid[13], uuid[14], uuid[15],
1844 		sb->devflags,
1845 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
1846 		(unsigned long long)le64_to_cpu(sb->events),
1847 		(unsigned long long)le64_to_cpu(sb->resync_offset),
1848 		le32_to_cpu(sb->sb_csum),
1849 		le32_to_cpu(sb->max_dev)
1850 		);
1851 }
1852 
1853 static void print_rdev(mdk_rdev_t *rdev, int major_version)
1854 {
1855 	char b[BDEVNAME_SIZE];
1856 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
1857 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
1858 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1859 	        rdev->desc_nr);
1860 	if (rdev->sb_loaded) {
1861 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
1862 		switch (major_version) {
1863 		case 0:
1864 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
1865 			break;
1866 		case 1:
1867 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
1868 			break;
1869 		}
1870 	} else
1871 		printk(KERN_INFO "md: no rdev superblock!\n");
1872 }
1873 
1874 static void md_print_devices(void)
1875 {
1876 	struct list_head *tmp;
1877 	mdk_rdev_t *rdev;
1878 	mddev_t *mddev;
1879 	char b[BDEVNAME_SIZE];
1880 
1881 	printk("\n");
1882 	printk("md:	**********************************\n");
1883 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1884 	printk("md:	**********************************\n");
1885 	for_each_mddev(mddev, tmp) {
1886 
1887 		if (mddev->bitmap)
1888 			bitmap_print_sb(mddev->bitmap);
1889 		else
1890 			printk("%s: ", mdname(mddev));
1891 		list_for_each_entry(rdev, &mddev->disks, same_set)
1892 			printk("<%s>", bdevname(rdev->bdev,b));
1893 		printk("\n");
1894 
1895 		list_for_each_entry(rdev, &mddev->disks, same_set)
1896 			print_rdev(rdev, mddev->major_version);
1897 	}
1898 	printk("md:	**********************************\n");
1899 	printk("\n");
1900 }
1901 
1902 
1903 static void sync_sbs(mddev_t * mddev, int nospares)
1904 {
1905 	/* Update each superblock (in-memory image), but
1906 	 * if we are allowed to, skip spares which already
1907 	 * have the right event counter, or have one earlier
1908 	 * (which would mean they aren't being marked as dirty
1909 	 * with the rest of the array)
1910 	 */
1911 	mdk_rdev_t *rdev;
1912 
1913 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1914 		if (rdev->sb_events == mddev->events ||
1915 		    (nospares &&
1916 		     rdev->raid_disk < 0 &&
1917 		     (rdev->sb_events&1)==0 &&
1918 		     rdev->sb_events+1 == mddev->events)) {
1919 			/* Don't update this superblock */
1920 			rdev->sb_loaded = 2;
1921 		} else {
1922 			super_types[mddev->major_version].
1923 				sync_super(mddev, rdev);
1924 			rdev->sb_loaded = 1;
1925 		}
1926 	}
1927 }
1928 
1929 static void md_update_sb(mddev_t * mddev, int force_change)
1930 {
1931 	mdk_rdev_t *rdev;
1932 	int sync_req;
1933 	int nospares = 0;
1934 
1935 	mddev->utime = get_seconds();
1936 	if (mddev->external)
1937 		return;
1938 repeat:
1939 	spin_lock_irq(&mddev->write_lock);
1940 
1941 	set_bit(MD_CHANGE_PENDING, &mddev->flags);
1942 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
1943 		force_change = 1;
1944 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
1945 		/* just a clean<-> dirty transition, possibly leave spares alone,
1946 		 * though if events isn't the right even/odd, we will have to do
1947 		 * spares after all
1948 		 */
1949 		nospares = 1;
1950 	if (force_change)
1951 		nospares = 0;
1952 	if (mddev->degraded)
1953 		/* If the array is degraded, then skipping spares is both
1954 		 * dangerous and fairly pointless.
1955 		 * Dangerous because a device that was removed from the array
1956 		 * might have a event_count that still looks up-to-date,
1957 		 * so it can be re-added without a resync.
1958 		 * Pointless because if there are any spares to skip,
1959 		 * then a recovery will happen and soon that array won't
1960 		 * be degraded any more and the spare can go back to sleep then.
1961 		 */
1962 		nospares = 0;
1963 
1964 	sync_req = mddev->in_sync;
1965 
1966 	/* If this is just a dirty<->clean transition, and the array is clean
1967 	 * and 'events' is odd, we can roll back to the previous clean state */
1968 	if (nospares
1969 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
1970 	    && (mddev->events & 1)
1971 	    && mddev->events != 1)
1972 		mddev->events--;
1973 	else {
1974 		/* otherwise we have to go forward and ... */
1975 		mddev->events ++;
1976 		if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
1977 			/* .. if the array isn't clean, insist on an odd 'events' */
1978 			if ((mddev->events&1)==0) {
1979 				mddev->events++;
1980 				nospares = 0;
1981 			}
1982 		} else {
1983 			/* otherwise insist on an even 'events' (for clean states) */
1984 			if ((mddev->events&1)) {
1985 				mddev->events++;
1986 				nospares = 0;
1987 			}
1988 		}
1989 	}
1990 
1991 	if (!mddev->events) {
1992 		/*
1993 		 * oops, this 64-bit counter should never wrap.
1994 		 * Either we are in around ~1 trillion A.C., assuming
1995 		 * 1 reboot per second, or we have a bug:
1996 		 */
1997 		MD_BUG();
1998 		mddev->events --;
1999 	}
2000 
2001 	/*
2002 	 * do not write anything to disk if using
2003 	 * nonpersistent superblocks
2004 	 */
2005 	if (!mddev->persistent) {
2006 		if (!mddev->external)
2007 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2008 
2009 		spin_unlock_irq(&mddev->write_lock);
2010 		wake_up(&mddev->sb_wait);
2011 		return;
2012 	}
2013 	sync_sbs(mddev, nospares);
2014 	spin_unlock_irq(&mddev->write_lock);
2015 
2016 	dprintk(KERN_INFO
2017 		"md: updating %s RAID superblock on device (in sync %d)\n",
2018 		mdname(mddev),mddev->in_sync);
2019 
2020 	bitmap_update_sb(mddev->bitmap);
2021 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2022 		char b[BDEVNAME_SIZE];
2023 		dprintk(KERN_INFO "md: ");
2024 		if (rdev->sb_loaded != 1)
2025 			continue; /* no noise on spare devices */
2026 		if (test_bit(Faulty, &rdev->flags))
2027 			dprintk("(skipping faulty ");
2028 
2029 		dprintk("%s ", bdevname(rdev->bdev,b));
2030 		if (!test_bit(Faulty, &rdev->flags)) {
2031 			md_super_write(mddev,rdev,
2032 				       rdev->sb_start, rdev->sb_size,
2033 				       rdev->sb_page);
2034 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2035 				bdevname(rdev->bdev,b),
2036 				(unsigned long long)rdev->sb_start);
2037 			rdev->sb_events = mddev->events;
2038 
2039 		} else
2040 			dprintk(")\n");
2041 		if (mddev->level == LEVEL_MULTIPATH)
2042 			/* only need to write one superblock... */
2043 			break;
2044 	}
2045 	md_super_wait(mddev);
2046 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2047 
2048 	spin_lock_irq(&mddev->write_lock);
2049 	if (mddev->in_sync != sync_req ||
2050 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2051 		/* have to write it out again */
2052 		spin_unlock_irq(&mddev->write_lock);
2053 		goto repeat;
2054 	}
2055 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2056 	spin_unlock_irq(&mddev->write_lock);
2057 	wake_up(&mddev->sb_wait);
2058 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2059 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2060 
2061 }
2062 
2063 /* words written to sysfs files may, or may not, be \n terminated.
2064  * We want to accept with case. For this we use cmd_match.
2065  */
2066 static int cmd_match(const char *cmd, const char *str)
2067 {
2068 	/* See if cmd, written into a sysfs file, matches
2069 	 * str.  They must either be the same, or cmd can
2070 	 * have a trailing newline
2071 	 */
2072 	while (*cmd && *str && *cmd == *str) {
2073 		cmd++;
2074 		str++;
2075 	}
2076 	if (*cmd == '\n')
2077 		cmd++;
2078 	if (*str || *cmd)
2079 		return 0;
2080 	return 1;
2081 }
2082 
2083 struct rdev_sysfs_entry {
2084 	struct attribute attr;
2085 	ssize_t (*show)(mdk_rdev_t *, char *);
2086 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2087 };
2088 
2089 static ssize_t
2090 state_show(mdk_rdev_t *rdev, char *page)
2091 {
2092 	char *sep = "";
2093 	size_t len = 0;
2094 
2095 	if (test_bit(Faulty, &rdev->flags)) {
2096 		len+= sprintf(page+len, "%sfaulty",sep);
2097 		sep = ",";
2098 	}
2099 	if (test_bit(In_sync, &rdev->flags)) {
2100 		len += sprintf(page+len, "%sin_sync",sep);
2101 		sep = ",";
2102 	}
2103 	if (test_bit(WriteMostly, &rdev->flags)) {
2104 		len += sprintf(page+len, "%swrite_mostly",sep);
2105 		sep = ",";
2106 	}
2107 	if (test_bit(Blocked, &rdev->flags)) {
2108 		len += sprintf(page+len, "%sblocked", sep);
2109 		sep = ",";
2110 	}
2111 	if (!test_bit(Faulty, &rdev->flags) &&
2112 	    !test_bit(In_sync, &rdev->flags)) {
2113 		len += sprintf(page+len, "%sspare", sep);
2114 		sep = ",";
2115 	}
2116 	return len+sprintf(page+len, "\n");
2117 }
2118 
2119 static ssize_t
2120 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2121 {
2122 	/* can write
2123 	 *  faulty  - simulates and error
2124 	 *  remove  - disconnects the device
2125 	 *  writemostly - sets write_mostly
2126 	 *  -writemostly - clears write_mostly
2127 	 *  blocked - sets the Blocked flag
2128 	 *  -blocked - clears the Blocked flag
2129 	 *  insync - sets Insync providing device isn't active
2130 	 */
2131 	int err = -EINVAL;
2132 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2133 		md_error(rdev->mddev, rdev);
2134 		err = 0;
2135 	} else if (cmd_match(buf, "remove")) {
2136 		if (rdev->raid_disk >= 0)
2137 			err = -EBUSY;
2138 		else {
2139 			mddev_t *mddev = rdev->mddev;
2140 			kick_rdev_from_array(rdev);
2141 			if (mddev->pers)
2142 				md_update_sb(mddev, 1);
2143 			md_new_event(mddev);
2144 			err = 0;
2145 		}
2146 	} else if (cmd_match(buf, "writemostly")) {
2147 		set_bit(WriteMostly, &rdev->flags);
2148 		err = 0;
2149 	} else if (cmd_match(buf, "-writemostly")) {
2150 		clear_bit(WriteMostly, &rdev->flags);
2151 		err = 0;
2152 	} else if (cmd_match(buf, "blocked")) {
2153 		set_bit(Blocked, &rdev->flags);
2154 		err = 0;
2155 	} else if (cmd_match(buf, "-blocked")) {
2156 		clear_bit(Blocked, &rdev->flags);
2157 		wake_up(&rdev->blocked_wait);
2158 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2159 		md_wakeup_thread(rdev->mddev->thread);
2160 
2161 		err = 0;
2162 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2163 		set_bit(In_sync, &rdev->flags);
2164 		err = 0;
2165 	}
2166 	if (!err && rdev->sysfs_state)
2167 		sysfs_notify_dirent(rdev->sysfs_state);
2168 	return err ? err : len;
2169 }
2170 static struct rdev_sysfs_entry rdev_state =
2171 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2172 
2173 static ssize_t
2174 errors_show(mdk_rdev_t *rdev, char *page)
2175 {
2176 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2177 }
2178 
2179 static ssize_t
2180 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2181 {
2182 	char *e;
2183 	unsigned long n = simple_strtoul(buf, &e, 10);
2184 	if (*buf && (*e == 0 || *e == '\n')) {
2185 		atomic_set(&rdev->corrected_errors, n);
2186 		return len;
2187 	}
2188 	return -EINVAL;
2189 }
2190 static struct rdev_sysfs_entry rdev_errors =
2191 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2192 
2193 static ssize_t
2194 slot_show(mdk_rdev_t *rdev, char *page)
2195 {
2196 	if (rdev->raid_disk < 0)
2197 		return sprintf(page, "none\n");
2198 	else
2199 		return sprintf(page, "%d\n", rdev->raid_disk);
2200 }
2201 
2202 static ssize_t
2203 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2204 {
2205 	char *e;
2206 	int err;
2207 	char nm[20];
2208 	int slot = simple_strtoul(buf, &e, 10);
2209 	if (strncmp(buf, "none", 4)==0)
2210 		slot = -1;
2211 	else if (e==buf || (*e && *e!= '\n'))
2212 		return -EINVAL;
2213 	if (rdev->mddev->pers && slot == -1) {
2214 		/* Setting 'slot' on an active array requires also
2215 		 * updating the 'rd%d' link, and communicating
2216 		 * with the personality with ->hot_*_disk.
2217 		 * For now we only support removing
2218 		 * failed/spare devices.  This normally happens automatically,
2219 		 * but not when the metadata is externally managed.
2220 		 */
2221 		if (rdev->raid_disk == -1)
2222 			return -EEXIST;
2223 		/* personality does all needed checks */
2224 		if (rdev->mddev->pers->hot_add_disk == NULL)
2225 			return -EINVAL;
2226 		err = rdev->mddev->pers->
2227 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2228 		if (err)
2229 			return err;
2230 		sprintf(nm, "rd%d", rdev->raid_disk);
2231 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2232 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2233 		md_wakeup_thread(rdev->mddev->thread);
2234 	} else if (rdev->mddev->pers) {
2235 		mdk_rdev_t *rdev2;
2236 		/* Activating a spare .. or possibly reactivating
2237 		 * if we ever get bitmaps working here.
2238 		 */
2239 
2240 		if (rdev->raid_disk != -1)
2241 			return -EBUSY;
2242 
2243 		if (rdev->mddev->pers->hot_add_disk == NULL)
2244 			return -EINVAL;
2245 
2246 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2247 			if (rdev2->raid_disk == slot)
2248 				return -EEXIST;
2249 
2250 		rdev->raid_disk = slot;
2251 		if (test_bit(In_sync, &rdev->flags))
2252 			rdev->saved_raid_disk = slot;
2253 		else
2254 			rdev->saved_raid_disk = -1;
2255 		err = rdev->mddev->pers->
2256 			hot_add_disk(rdev->mddev, rdev);
2257 		if (err) {
2258 			rdev->raid_disk = -1;
2259 			return err;
2260 		} else
2261 			sysfs_notify_dirent(rdev->sysfs_state);
2262 		sprintf(nm, "rd%d", rdev->raid_disk);
2263 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2264 			printk(KERN_WARNING
2265 			       "md: cannot register "
2266 			       "%s for %s\n",
2267 			       nm, mdname(rdev->mddev));
2268 
2269 		/* don't wakeup anyone, leave that to userspace. */
2270 	} else {
2271 		if (slot >= rdev->mddev->raid_disks)
2272 			return -ENOSPC;
2273 		rdev->raid_disk = slot;
2274 		/* assume it is working */
2275 		clear_bit(Faulty, &rdev->flags);
2276 		clear_bit(WriteMostly, &rdev->flags);
2277 		set_bit(In_sync, &rdev->flags);
2278 		sysfs_notify_dirent(rdev->sysfs_state);
2279 	}
2280 	return len;
2281 }
2282 
2283 
2284 static struct rdev_sysfs_entry rdev_slot =
2285 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2286 
2287 static ssize_t
2288 offset_show(mdk_rdev_t *rdev, char *page)
2289 {
2290 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2291 }
2292 
2293 static ssize_t
2294 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2295 {
2296 	char *e;
2297 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2298 	if (e==buf || (*e && *e != '\n'))
2299 		return -EINVAL;
2300 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2301 		return -EBUSY;
2302 	if (rdev->sectors && rdev->mddev->external)
2303 		/* Must set offset before size, so overlap checks
2304 		 * can be sane */
2305 		return -EBUSY;
2306 	rdev->data_offset = offset;
2307 	return len;
2308 }
2309 
2310 static struct rdev_sysfs_entry rdev_offset =
2311 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2312 
2313 static ssize_t
2314 rdev_size_show(mdk_rdev_t *rdev, char *page)
2315 {
2316 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2317 }
2318 
2319 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2320 {
2321 	/* check if two start/length pairs overlap */
2322 	if (s1+l1 <= s2)
2323 		return 0;
2324 	if (s2+l2 <= s1)
2325 		return 0;
2326 	return 1;
2327 }
2328 
2329 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2330 {
2331 	unsigned long long blocks;
2332 	sector_t new;
2333 
2334 	if (strict_strtoull(buf, 10, &blocks) < 0)
2335 		return -EINVAL;
2336 
2337 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2338 		return -EINVAL; /* sector conversion overflow */
2339 
2340 	new = blocks * 2;
2341 	if (new != blocks * 2)
2342 		return -EINVAL; /* unsigned long long to sector_t overflow */
2343 
2344 	*sectors = new;
2345 	return 0;
2346 }
2347 
2348 static ssize_t
2349 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2350 {
2351 	mddev_t *my_mddev = rdev->mddev;
2352 	sector_t oldsectors = rdev->sectors;
2353 	sector_t sectors;
2354 
2355 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2356 		return -EINVAL;
2357 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2358 		if (my_mddev->persistent) {
2359 			sectors = super_types[my_mddev->major_version].
2360 				rdev_size_change(rdev, sectors);
2361 			if (!sectors)
2362 				return -EBUSY;
2363 		} else if (!sectors)
2364 			sectors = (rdev->bdev->bd_inode->i_size >> 9) -
2365 				rdev->data_offset;
2366 	}
2367 	if (sectors < my_mddev->dev_sectors)
2368 		return -EINVAL; /* component must fit device */
2369 
2370 	rdev->sectors = sectors;
2371 	if (sectors > oldsectors && my_mddev->external) {
2372 		/* need to check that all other rdevs with the same ->bdev
2373 		 * do not overlap.  We need to unlock the mddev to avoid
2374 		 * a deadlock.  We have already changed rdev->sectors, and if
2375 		 * we have to change it back, we will have the lock again.
2376 		 */
2377 		mddev_t *mddev;
2378 		int overlap = 0;
2379 		struct list_head *tmp;
2380 
2381 		mddev_unlock(my_mddev);
2382 		for_each_mddev(mddev, tmp) {
2383 			mdk_rdev_t *rdev2;
2384 
2385 			mddev_lock(mddev);
2386 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2387 				if (test_bit(AllReserved, &rdev2->flags) ||
2388 				    (rdev->bdev == rdev2->bdev &&
2389 				     rdev != rdev2 &&
2390 				     overlaps(rdev->data_offset, rdev->sectors,
2391 					      rdev2->data_offset,
2392 					      rdev2->sectors))) {
2393 					overlap = 1;
2394 					break;
2395 				}
2396 			mddev_unlock(mddev);
2397 			if (overlap) {
2398 				mddev_put(mddev);
2399 				break;
2400 			}
2401 		}
2402 		mddev_lock(my_mddev);
2403 		if (overlap) {
2404 			/* Someone else could have slipped in a size
2405 			 * change here, but doing so is just silly.
2406 			 * We put oldsectors back because we *know* it is
2407 			 * safe, and trust userspace not to race with
2408 			 * itself
2409 			 */
2410 			rdev->sectors = oldsectors;
2411 			return -EBUSY;
2412 		}
2413 	}
2414 	return len;
2415 }
2416 
2417 static struct rdev_sysfs_entry rdev_size =
2418 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2419 
2420 static struct attribute *rdev_default_attrs[] = {
2421 	&rdev_state.attr,
2422 	&rdev_errors.attr,
2423 	&rdev_slot.attr,
2424 	&rdev_offset.attr,
2425 	&rdev_size.attr,
2426 	NULL,
2427 };
2428 static ssize_t
2429 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2430 {
2431 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2432 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2433 	mddev_t *mddev = rdev->mddev;
2434 	ssize_t rv;
2435 
2436 	if (!entry->show)
2437 		return -EIO;
2438 
2439 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2440 	if (!rv) {
2441 		if (rdev->mddev == NULL)
2442 			rv = -EBUSY;
2443 		else
2444 			rv = entry->show(rdev, page);
2445 		mddev_unlock(mddev);
2446 	}
2447 	return rv;
2448 }
2449 
2450 static ssize_t
2451 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2452 	      const char *page, size_t length)
2453 {
2454 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2455 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2456 	ssize_t rv;
2457 	mddev_t *mddev = rdev->mddev;
2458 
2459 	if (!entry->store)
2460 		return -EIO;
2461 	if (!capable(CAP_SYS_ADMIN))
2462 		return -EACCES;
2463 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2464 	if (!rv) {
2465 		if (rdev->mddev == NULL)
2466 			rv = -EBUSY;
2467 		else
2468 			rv = entry->store(rdev, page, length);
2469 		mddev_unlock(mddev);
2470 	}
2471 	return rv;
2472 }
2473 
2474 static void rdev_free(struct kobject *ko)
2475 {
2476 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2477 	kfree(rdev);
2478 }
2479 static struct sysfs_ops rdev_sysfs_ops = {
2480 	.show		= rdev_attr_show,
2481 	.store		= rdev_attr_store,
2482 };
2483 static struct kobj_type rdev_ktype = {
2484 	.release	= rdev_free,
2485 	.sysfs_ops	= &rdev_sysfs_ops,
2486 	.default_attrs	= rdev_default_attrs,
2487 };
2488 
2489 /*
2490  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2491  *
2492  * mark the device faulty if:
2493  *
2494  *   - the device is nonexistent (zero size)
2495  *   - the device has no valid superblock
2496  *
2497  * a faulty rdev _never_ has rdev->sb set.
2498  */
2499 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2500 {
2501 	char b[BDEVNAME_SIZE];
2502 	int err;
2503 	mdk_rdev_t *rdev;
2504 	sector_t size;
2505 
2506 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2507 	if (!rdev) {
2508 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2509 		return ERR_PTR(-ENOMEM);
2510 	}
2511 
2512 	if ((err = alloc_disk_sb(rdev)))
2513 		goto abort_free;
2514 
2515 	err = lock_rdev(rdev, newdev, super_format == -2);
2516 	if (err)
2517 		goto abort_free;
2518 
2519 	kobject_init(&rdev->kobj, &rdev_ktype);
2520 
2521 	rdev->desc_nr = -1;
2522 	rdev->saved_raid_disk = -1;
2523 	rdev->raid_disk = -1;
2524 	rdev->flags = 0;
2525 	rdev->data_offset = 0;
2526 	rdev->sb_events = 0;
2527 	atomic_set(&rdev->nr_pending, 0);
2528 	atomic_set(&rdev->read_errors, 0);
2529 	atomic_set(&rdev->corrected_errors, 0);
2530 
2531 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2532 	if (!size) {
2533 		printk(KERN_WARNING
2534 			"md: %s has zero or unknown size, marking faulty!\n",
2535 			bdevname(rdev->bdev,b));
2536 		err = -EINVAL;
2537 		goto abort_free;
2538 	}
2539 
2540 	if (super_format >= 0) {
2541 		err = super_types[super_format].
2542 			load_super(rdev, NULL, super_minor);
2543 		if (err == -EINVAL) {
2544 			printk(KERN_WARNING
2545 				"md: %s does not have a valid v%d.%d "
2546 			       "superblock, not importing!\n",
2547 				bdevname(rdev->bdev,b),
2548 			       super_format, super_minor);
2549 			goto abort_free;
2550 		}
2551 		if (err < 0) {
2552 			printk(KERN_WARNING
2553 				"md: could not read %s's sb, not importing!\n",
2554 				bdevname(rdev->bdev,b));
2555 			goto abort_free;
2556 		}
2557 	}
2558 
2559 	INIT_LIST_HEAD(&rdev->same_set);
2560 	init_waitqueue_head(&rdev->blocked_wait);
2561 
2562 	return rdev;
2563 
2564 abort_free:
2565 	if (rdev->sb_page) {
2566 		if (rdev->bdev)
2567 			unlock_rdev(rdev);
2568 		free_disk_sb(rdev);
2569 	}
2570 	kfree(rdev);
2571 	return ERR_PTR(err);
2572 }
2573 
2574 /*
2575  * Check a full RAID array for plausibility
2576  */
2577 
2578 
2579 static void analyze_sbs(mddev_t * mddev)
2580 {
2581 	int i;
2582 	mdk_rdev_t *rdev, *freshest, *tmp;
2583 	char b[BDEVNAME_SIZE];
2584 
2585 	freshest = NULL;
2586 	rdev_for_each(rdev, tmp, mddev)
2587 		switch (super_types[mddev->major_version].
2588 			load_super(rdev, freshest, mddev->minor_version)) {
2589 		case 1:
2590 			freshest = rdev;
2591 			break;
2592 		case 0:
2593 			break;
2594 		default:
2595 			printk( KERN_ERR \
2596 				"md: fatal superblock inconsistency in %s"
2597 				" -- removing from array\n",
2598 				bdevname(rdev->bdev,b));
2599 			kick_rdev_from_array(rdev);
2600 		}
2601 
2602 
2603 	super_types[mddev->major_version].
2604 		validate_super(mddev, freshest);
2605 
2606 	i = 0;
2607 	rdev_for_each(rdev, tmp, mddev) {
2608 		if (rdev->desc_nr >= mddev->max_disks ||
2609 		    i > mddev->max_disks) {
2610 			printk(KERN_WARNING
2611 			       "md: %s: %s: only %d devices permitted\n",
2612 			       mdname(mddev), bdevname(rdev->bdev, b),
2613 			       mddev->max_disks);
2614 			kick_rdev_from_array(rdev);
2615 			continue;
2616 		}
2617 		if (rdev != freshest)
2618 			if (super_types[mddev->major_version].
2619 			    validate_super(mddev, rdev)) {
2620 				printk(KERN_WARNING "md: kicking non-fresh %s"
2621 					" from array!\n",
2622 					bdevname(rdev->bdev,b));
2623 				kick_rdev_from_array(rdev);
2624 				continue;
2625 			}
2626 		if (mddev->level == LEVEL_MULTIPATH) {
2627 			rdev->desc_nr = i++;
2628 			rdev->raid_disk = rdev->desc_nr;
2629 			set_bit(In_sync, &rdev->flags);
2630 		} else if (rdev->raid_disk >= mddev->raid_disks) {
2631 			rdev->raid_disk = -1;
2632 			clear_bit(In_sync, &rdev->flags);
2633 		}
2634 	}
2635 }
2636 
2637 static void md_safemode_timeout(unsigned long data);
2638 
2639 static ssize_t
2640 safe_delay_show(mddev_t *mddev, char *page)
2641 {
2642 	int msec = (mddev->safemode_delay*1000)/HZ;
2643 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2644 }
2645 static ssize_t
2646 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2647 {
2648 	int scale=1;
2649 	int dot=0;
2650 	int i;
2651 	unsigned long msec;
2652 	char buf[30];
2653 
2654 	/* remove a period, and count digits after it */
2655 	if (len >= sizeof(buf))
2656 		return -EINVAL;
2657 	strlcpy(buf, cbuf, sizeof(buf));
2658 	for (i=0; i<len; i++) {
2659 		if (dot) {
2660 			if (isdigit(buf[i])) {
2661 				buf[i-1] = buf[i];
2662 				scale *= 10;
2663 			}
2664 			buf[i] = 0;
2665 		} else if (buf[i] == '.') {
2666 			dot=1;
2667 			buf[i] = 0;
2668 		}
2669 	}
2670 	if (strict_strtoul(buf, 10, &msec) < 0)
2671 		return -EINVAL;
2672 	msec = (msec * 1000) / scale;
2673 	if (msec == 0)
2674 		mddev->safemode_delay = 0;
2675 	else {
2676 		unsigned long old_delay = mddev->safemode_delay;
2677 		mddev->safemode_delay = (msec*HZ)/1000;
2678 		if (mddev->safemode_delay == 0)
2679 			mddev->safemode_delay = 1;
2680 		if (mddev->safemode_delay < old_delay)
2681 			md_safemode_timeout((unsigned long)mddev);
2682 	}
2683 	return len;
2684 }
2685 static struct md_sysfs_entry md_safe_delay =
2686 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2687 
2688 static ssize_t
2689 level_show(mddev_t *mddev, char *page)
2690 {
2691 	struct mdk_personality *p = mddev->pers;
2692 	if (p)
2693 		return sprintf(page, "%s\n", p->name);
2694 	else if (mddev->clevel[0])
2695 		return sprintf(page, "%s\n", mddev->clevel);
2696 	else if (mddev->level != LEVEL_NONE)
2697 		return sprintf(page, "%d\n", mddev->level);
2698 	else
2699 		return 0;
2700 }
2701 
2702 static ssize_t
2703 level_store(mddev_t *mddev, const char *buf, size_t len)
2704 {
2705 	char level[16];
2706 	ssize_t rv = len;
2707 	struct mdk_personality *pers;
2708 	void *priv;
2709 	mdk_rdev_t *rdev;
2710 
2711 	if (mddev->pers == NULL) {
2712 		if (len == 0)
2713 			return 0;
2714 		if (len >= sizeof(mddev->clevel))
2715 			return -ENOSPC;
2716 		strncpy(mddev->clevel, buf, len);
2717 		if (mddev->clevel[len-1] == '\n')
2718 			len--;
2719 		mddev->clevel[len] = 0;
2720 		mddev->level = LEVEL_NONE;
2721 		return rv;
2722 	}
2723 
2724 	/* request to change the personality.  Need to ensure:
2725 	 *  - array is not engaged in resync/recovery/reshape
2726 	 *  - old personality can be suspended
2727 	 *  - new personality will access other array.
2728 	 */
2729 
2730 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
2731 		return -EBUSY;
2732 
2733 	if (!mddev->pers->quiesce) {
2734 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
2735 		       mdname(mddev), mddev->pers->name);
2736 		return -EINVAL;
2737 	}
2738 
2739 	/* Now find the new personality */
2740 	if (len == 0 || len >= sizeof(level))
2741 		return -EINVAL;
2742 	strncpy(level, buf, len);
2743 	if (level[len-1] == '\n')
2744 		len--;
2745 	level[len] = 0;
2746 
2747 	request_module("md-%s", level);
2748 	spin_lock(&pers_lock);
2749 	pers = find_pers(LEVEL_NONE, level);
2750 	if (!pers || !try_module_get(pers->owner)) {
2751 		spin_unlock(&pers_lock);
2752 		printk(KERN_WARNING "md: personality %s not loaded\n", level);
2753 		return -EINVAL;
2754 	}
2755 	spin_unlock(&pers_lock);
2756 
2757 	if (pers == mddev->pers) {
2758 		/* Nothing to do! */
2759 		module_put(pers->owner);
2760 		return rv;
2761 	}
2762 	if (!pers->takeover) {
2763 		module_put(pers->owner);
2764 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
2765 		       mdname(mddev), level);
2766 		return -EINVAL;
2767 	}
2768 
2769 	/* ->takeover must set new_* and/or delta_disks
2770 	 * if it succeeds, and may set them when it fails.
2771 	 */
2772 	priv = pers->takeover(mddev);
2773 	if (IS_ERR(priv)) {
2774 		mddev->new_level = mddev->level;
2775 		mddev->new_layout = mddev->layout;
2776 		mddev->new_chunk_sectors = mddev->chunk_sectors;
2777 		mddev->raid_disks -= mddev->delta_disks;
2778 		mddev->delta_disks = 0;
2779 		module_put(pers->owner);
2780 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
2781 		       mdname(mddev), level);
2782 		return PTR_ERR(priv);
2783 	}
2784 
2785 	/* Looks like we have a winner */
2786 	mddev_suspend(mddev);
2787 	mddev->pers->stop(mddev);
2788 	module_put(mddev->pers->owner);
2789 	/* Invalidate devices that are now superfluous */
2790 	list_for_each_entry(rdev, &mddev->disks, same_set)
2791 		if (rdev->raid_disk >= mddev->raid_disks) {
2792 			rdev->raid_disk = -1;
2793 			clear_bit(In_sync, &rdev->flags);
2794 		}
2795 	mddev->pers = pers;
2796 	mddev->private = priv;
2797 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
2798 	mddev->level = mddev->new_level;
2799 	mddev->layout = mddev->new_layout;
2800 	mddev->chunk_sectors = mddev->new_chunk_sectors;
2801 	mddev->delta_disks = 0;
2802 	pers->run(mddev);
2803 	mddev_resume(mddev);
2804 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
2805 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2806 	md_wakeup_thread(mddev->thread);
2807 	return rv;
2808 }
2809 
2810 static struct md_sysfs_entry md_level =
2811 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
2812 
2813 
2814 static ssize_t
2815 layout_show(mddev_t *mddev, char *page)
2816 {
2817 	/* just a number, not meaningful for all levels */
2818 	if (mddev->reshape_position != MaxSector &&
2819 	    mddev->layout != mddev->new_layout)
2820 		return sprintf(page, "%d (%d)\n",
2821 			       mddev->new_layout, mddev->layout);
2822 	return sprintf(page, "%d\n", mddev->layout);
2823 }
2824 
2825 static ssize_t
2826 layout_store(mddev_t *mddev, const char *buf, size_t len)
2827 {
2828 	char *e;
2829 	unsigned long n = simple_strtoul(buf, &e, 10);
2830 
2831 	if (!*buf || (*e && *e != '\n'))
2832 		return -EINVAL;
2833 
2834 	if (mddev->pers) {
2835 		int err;
2836 		if (mddev->pers->check_reshape == NULL)
2837 			return -EBUSY;
2838 		mddev->new_layout = n;
2839 		err = mddev->pers->check_reshape(mddev);
2840 		if (err) {
2841 			mddev->new_layout = mddev->layout;
2842 			return err;
2843 		}
2844 	} else {
2845 		mddev->new_layout = n;
2846 		if (mddev->reshape_position == MaxSector)
2847 			mddev->layout = n;
2848 	}
2849 	return len;
2850 }
2851 static struct md_sysfs_entry md_layout =
2852 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
2853 
2854 
2855 static ssize_t
2856 raid_disks_show(mddev_t *mddev, char *page)
2857 {
2858 	if (mddev->raid_disks == 0)
2859 		return 0;
2860 	if (mddev->reshape_position != MaxSector &&
2861 	    mddev->delta_disks != 0)
2862 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
2863 			       mddev->raid_disks - mddev->delta_disks);
2864 	return sprintf(page, "%d\n", mddev->raid_disks);
2865 }
2866 
2867 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2868 
2869 static ssize_t
2870 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2871 {
2872 	char *e;
2873 	int rv = 0;
2874 	unsigned long n = simple_strtoul(buf, &e, 10);
2875 
2876 	if (!*buf || (*e && *e != '\n'))
2877 		return -EINVAL;
2878 
2879 	if (mddev->pers)
2880 		rv = update_raid_disks(mddev, n);
2881 	else if (mddev->reshape_position != MaxSector) {
2882 		int olddisks = mddev->raid_disks - mddev->delta_disks;
2883 		mddev->delta_disks = n - olddisks;
2884 		mddev->raid_disks = n;
2885 	} else
2886 		mddev->raid_disks = n;
2887 	return rv ? rv : len;
2888 }
2889 static struct md_sysfs_entry md_raid_disks =
2890 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
2891 
2892 static ssize_t
2893 chunk_size_show(mddev_t *mddev, char *page)
2894 {
2895 	if (mddev->reshape_position != MaxSector &&
2896 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
2897 		return sprintf(page, "%d (%d)\n",
2898 			       mddev->new_chunk_sectors << 9,
2899 			       mddev->chunk_sectors << 9);
2900 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
2901 }
2902 
2903 static ssize_t
2904 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2905 {
2906 	char *e;
2907 	unsigned long n = simple_strtoul(buf, &e, 10);
2908 
2909 	if (!*buf || (*e && *e != '\n'))
2910 		return -EINVAL;
2911 
2912 	if (mddev->pers) {
2913 		int err;
2914 		if (mddev->pers->check_reshape == NULL)
2915 			return -EBUSY;
2916 		mddev->new_chunk_sectors = n >> 9;
2917 		err = mddev->pers->check_reshape(mddev);
2918 		if (err) {
2919 			mddev->new_chunk_sectors = mddev->chunk_sectors;
2920 			return err;
2921 		}
2922 	} else {
2923 		mddev->new_chunk_sectors = n >> 9;
2924 		if (mddev->reshape_position == MaxSector)
2925 			mddev->chunk_sectors = n >> 9;
2926 	}
2927 	return len;
2928 }
2929 static struct md_sysfs_entry md_chunk_size =
2930 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
2931 
2932 static ssize_t
2933 resync_start_show(mddev_t *mddev, char *page)
2934 {
2935 	if (mddev->recovery_cp == MaxSector)
2936 		return sprintf(page, "none\n");
2937 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
2938 }
2939 
2940 static ssize_t
2941 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
2942 {
2943 	char *e;
2944 	unsigned long long n = simple_strtoull(buf, &e, 10);
2945 
2946 	if (mddev->pers)
2947 		return -EBUSY;
2948 	if (!*buf || (*e && *e != '\n'))
2949 		return -EINVAL;
2950 
2951 	mddev->recovery_cp = n;
2952 	return len;
2953 }
2954 static struct md_sysfs_entry md_resync_start =
2955 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
2956 
2957 /*
2958  * The array state can be:
2959  *
2960  * clear
2961  *     No devices, no size, no level
2962  *     Equivalent to STOP_ARRAY ioctl
2963  * inactive
2964  *     May have some settings, but array is not active
2965  *        all IO results in error
2966  *     When written, doesn't tear down array, but just stops it
2967  * suspended (not supported yet)
2968  *     All IO requests will block. The array can be reconfigured.
2969  *     Writing this, if accepted, will block until array is quiescent
2970  * readonly
2971  *     no resync can happen.  no superblocks get written.
2972  *     write requests fail
2973  * read-auto
2974  *     like readonly, but behaves like 'clean' on a write request.
2975  *
2976  * clean - no pending writes, but otherwise active.
2977  *     When written to inactive array, starts without resync
2978  *     If a write request arrives then
2979  *       if metadata is known, mark 'dirty' and switch to 'active'.
2980  *       if not known, block and switch to write-pending
2981  *     If written to an active array that has pending writes, then fails.
2982  * active
2983  *     fully active: IO and resync can be happening.
2984  *     When written to inactive array, starts with resync
2985  *
2986  * write-pending
2987  *     clean, but writes are blocked waiting for 'active' to be written.
2988  *
2989  * active-idle
2990  *     like active, but no writes have been seen for a while (100msec).
2991  *
2992  */
2993 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
2994 		   write_pending, active_idle, bad_word};
2995 static char *array_states[] = {
2996 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
2997 	"write-pending", "active-idle", NULL };
2998 
2999 static int match_word(const char *word, char **list)
3000 {
3001 	int n;
3002 	for (n=0; list[n]; n++)
3003 		if (cmd_match(word, list[n]))
3004 			break;
3005 	return n;
3006 }
3007 
3008 static ssize_t
3009 array_state_show(mddev_t *mddev, char *page)
3010 {
3011 	enum array_state st = inactive;
3012 
3013 	if (mddev->pers)
3014 		switch(mddev->ro) {
3015 		case 1:
3016 			st = readonly;
3017 			break;
3018 		case 2:
3019 			st = read_auto;
3020 			break;
3021 		case 0:
3022 			if (mddev->in_sync)
3023 				st = clean;
3024 			else if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
3025 				st = write_pending;
3026 			else if (mddev->safemode)
3027 				st = active_idle;
3028 			else
3029 				st = active;
3030 		}
3031 	else {
3032 		if (list_empty(&mddev->disks) &&
3033 		    mddev->raid_disks == 0 &&
3034 		    mddev->dev_sectors == 0)
3035 			st = clear;
3036 		else
3037 			st = inactive;
3038 	}
3039 	return sprintf(page, "%s\n", array_states[st]);
3040 }
3041 
3042 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3043 static int do_md_run(mddev_t * mddev);
3044 static int restart_array(mddev_t *mddev);
3045 
3046 static ssize_t
3047 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3048 {
3049 	int err = -EINVAL;
3050 	enum array_state st = match_word(buf, array_states);
3051 	switch(st) {
3052 	case bad_word:
3053 		break;
3054 	case clear:
3055 		/* stopping an active array */
3056 		if (atomic_read(&mddev->openers) > 0)
3057 			return -EBUSY;
3058 		err = do_md_stop(mddev, 0, 0);
3059 		break;
3060 	case inactive:
3061 		/* stopping an active array */
3062 		if (mddev->pers) {
3063 			if (atomic_read(&mddev->openers) > 0)
3064 				return -EBUSY;
3065 			err = do_md_stop(mddev, 2, 0);
3066 		} else
3067 			err = 0; /* already inactive */
3068 		break;
3069 	case suspended:
3070 		break; /* not supported yet */
3071 	case readonly:
3072 		if (mddev->pers)
3073 			err = do_md_stop(mddev, 1, 0);
3074 		else {
3075 			mddev->ro = 1;
3076 			set_disk_ro(mddev->gendisk, 1);
3077 			err = do_md_run(mddev);
3078 		}
3079 		break;
3080 	case read_auto:
3081 		if (mddev->pers) {
3082 			if (mddev->ro == 0)
3083 				err = do_md_stop(mddev, 1, 0);
3084 			else if (mddev->ro == 1)
3085 				err = restart_array(mddev);
3086 			if (err == 0) {
3087 				mddev->ro = 2;
3088 				set_disk_ro(mddev->gendisk, 0);
3089 			}
3090 		} else {
3091 			mddev->ro = 2;
3092 			err = do_md_run(mddev);
3093 		}
3094 		break;
3095 	case clean:
3096 		if (mddev->pers) {
3097 			restart_array(mddev);
3098 			spin_lock_irq(&mddev->write_lock);
3099 			if (atomic_read(&mddev->writes_pending) == 0) {
3100 				if (mddev->in_sync == 0) {
3101 					mddev->in_sync = 1;
3102 					if (mddev->safemode == 1)
3103 						mddev->safemode = 0;
3104 					if (mddev->persistent)
3105 						set_bit(MD_CHANGE_CLEAN,
3106 							&mddev->flags);
3107 				}
3108 				err = 0;
3109 			} else
3110 				err = -EBUSY;
3111 			spin_unlock_irq(&mddev->write_lock);
3112 		} else
3113 			err = -EINVAL;
3114 		break;
3115 	case active:
3116 		if (mddev->pers) {
3117 			restart_array(mddev);
3118 			if (mddev->external)
3119 				clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
3120 			wake_up(&mddev->sb_wait);
3121 			err = 0;
3122 		} else {
3123 			mddev->ro = 0;
3124 			set_disk_ro(mddev->gendisk, 0);
3125 			err = do_md_run(mddev);
3126 		}
3127 		break;
3128 	case write_pending:
3129 	case active_idle:
3130 		/* these cannot be set */
3131 		break;
3132 	}
3133 	if (err)
3134 		return err;
3135 	else {
3136 		sysfs_notify_dirent(mddev->sysfs_state);
3137 		return len;
3138 	}
3139 }
3140 static struct md_sysfs_entry md_array_state =
3141 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3142 
3143 static ssize_t
3144 null_show(mddev_t *mddev, char *page)
3145 {
3146 	return -EINVAL;
3147 }
3148 
3149 static ssize_t
3150 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3151 {
3152 	/* buf must be %d:%d\n? giving major and minor numbers */
3153 	/* The new device is added to the array.
3154 	 * If the array has a persistent superblock, we read the
3155 	 * superblock to initialise info and check validity.
3156 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3157 	 * which mainly checks size.
3158 	 */
3159 	char *e;
3160 	int major = simple_strtoul(buf, &e, 10);
3161 	int minor;
3162 	dev_t dev;
3163 	mdk_rdev_t *rdev;
3164 	int err;
3165 
3166 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3167 		return -EINVAL;
3168 	minor = simple_strtoul(e+1, &e, 10);
3169 	if (*e && *e != '\n')
3170 		return -EINVAL;
3171 	dev = MKDEV(major, minor);
3172 	if (major != MAJOR(dev) ||
3173 	    minor != MINOR(dev))
3174 		return -EOVERFLOW;
3175 
3176 
3177 	if (mddev->persistent) {
3178 		rdev = md_import_device(dev, mddev->major_version,
3179 					mddev->minor_version);
3180 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3181 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3182 						       mdk_rdev_t, same_set);
3183 			err = super_types[mddev->major_version]
3184 				.load_super(rdev, rdev0, mddev->minor_version);
3185 			if (err < 0)
3186 				goto out;
3187 		}
3188 	} else if (mddev->external)
3189 		rdev = md_import_device(dev, -2, -1);
3190 	else
3191 		rdev = md_import_device(dev, -1, -1);
3192 
3193 	if (IS_ERR(rdev))
3194 		return PTR_ERR(rdev);
3195 	err = bind_rdev_to_array(rdev, mddev);
3196  out:
3197 	if (err)
3198 		export_rdev(rdev);
3199 	return err ? err : len;
3200 }
3201 
3202 static struct md_sysfs_entry md_new_device =
3203 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3204 
3205 static ssize_t
3206 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3207 {
3208 	char *end;
3209 	unsigned long chunk, end_chunk;
3210 
3211 	if (!mddev->bitmap)
3212 		goto out;
3213 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3214 	while (*buf) {
3215 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3216 		if (buf == end) break;
3217 		if (*end == '-') { /* range */
3218 			buf = end + 1;
3219 			end_chunk = simple_strtoul(buf, &end, 0);
3220 			if (buf == end) break;
3221 		}
3222 		if (*end && !isspace(*end)) break;
3223 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3224 		buf = end;
3225 		while (isspace(*buf)) buf++;
3226 	}
3227 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3228 out:
3229 	return len;
3230 }
3231 
3232 static struct md_sysfs_entry md_bitmap =
3233 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3234 
3235 static ssize_t
3236 size_show(mddev_t *mddev, char *page)
3237 {
3238 	return sprintf(page, "%llu\n",
3239 		(unsigned long long)mddev->dev_sectors / 2);
3240 }
3241 
3242 static int update_size(mddev_t *mddev, sector_t num_sectors);
3243 
3244 static ssize_t
3245 size_store(mddev_t *mddev, const char *buf, size_t len)
3246 {
3247 	/* If array is inactive, we can reduce the component size, but
3248 	 * not increase it (except from 0).
3249 	 * If array is active, we can try an on-line resize
3250 	 */
3251 	sector_t sectors;
3252 	int err = strict_blocks_to_sectors(buf, &sectors);
3253 
3254 	if (err < 0)
3255 		return err;
3256 	if (mddev->pers) {
3257 		err = update_size(mddev, sectors);
3258 		md_update_sb(mddev, 1);
3259 	} else {
3260 		if (mddev->dev_sectors == 0 ||
3261 		    mddev->dev_sectors > sectors)
3262 			mddev->dev_sectors = sectors;
3263 		else
3264 			err = -ENOSPC;
3265 	}
3266 	return err ? err : len;
3267 }
3268 
3269 static struct md_sysfs_entry md_size =
3270 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3271 
3272 
3273 /* Metdata version.
3274  * This is one of
3275  *   'none' for arrays with no metadata (good luck...)
3276  *   'external' for arrays with externally managed metadata,
3277  * or N.M for internally known formats
3278  */
3279 static ssize_t
3280 metadata_show(mddev_t *mddev, char *page)
3281 {
3282 	if (mddev->persistent)
3283 		return sprintf(page, "%d.%d\n",
3284 			       mddev->major_version, mddev->minor_version);
3285 	else if (mddev->external)
3286 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3287 	else
3288 		return sprintf(page, "none\n");
3289 }
3290 
3291 static ssize_t
3292 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3293 {
3294 	int major, minor;
3295 	char *e;
3296 	/* Changing the details of 'external' metadata is
3297 	 * always permitted.  Otherwise there must be
3298 	 * no devices attached to the array.
3299 	 */
3300 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3301 		;
3302 	else if (!list_empty(&mddev->disks))
3303 		return -EBUSY;
3304 
3305 	if (cmd_match(buf, "none")) {
3306 		mddev->persistent = 0;
3307 		mddev->external = 0;
3308 		mddev->major_version = 0;
3309 		mddev->minor_version = 90;
3310 		return len;
3311 	}
3312 	if (strncmp(buf, "external:", 9) == 0) {
3313 		size_t namelen = len-9;
3314 		if (namelen >= sizeof(mddev->metadata_type))
3315 			namelen = sizeof(mddev->metadata_type)-1;
3316 		strncpy(mddev->metadata_type, buf+9, namelen);
3317 		mddev->metadata_type[namelen] = 0;
3318 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3319 			mddev->metadata_type[--namelen] = 0;
3320 		mddev->persistent = 0;
3321 		mddev->external = 1;
3322 		mddev->major_version = 0;
3323 		mddev->minor_version = 90;
3324 		return len;
3325 	}
3326 	major = simple_strtoul(buf, &e, 10);
3327 	if (e==buf || *e != '.')
3328 		return -EINVAL;
3329 	buf = e+1;
3330 	minor = simple_strtoul(buf, &e, 10);
3331 	if (e==buf || (*e && *e != '\n') )
3332 		return -EINVAL;
3333 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3334 		return -ENOENT;
3335 	mddev->major_version = major;
3336 	mddev->minor_version = minor;
3337 	mddev->persistent = 1;
3338 	mddev->external = 0;
3339 	return len;
3340 }
3341 
3342 static struct md_sysfs_entry md_metadata =
3343 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3344 
3345 static ssize_t
3346 action_show(mddev_t *mddev, char *page)
3347 {
3348 	char *type = "idle";
3349 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3350 		type = "frozen";
3351 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3352 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3353 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3354 			type = "reshape";
3355 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3356 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3357 				type = "resync";
3358 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3359 				type = "check";
3360 			else
3361 				type = "repair";
3362 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3363 			type = "recover";
3364 	}
3365 	return sprintf(page, "%s\n", type);
3366 }
3367 
3368 static ssize_t
3369 action_store(mddev_t *mddev, const char *page, size_t len)
3370 {
3371 	if (!mddev->pers || !mddev->pers->sync_request)
3372 		return -EINVAL;
3373 
3374 	if (cmd_match(page, "frozen"))
3375 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3376 	else
3377 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3378 
3379 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
3380 		if (mddev->sync_thread) {
3381 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3382 			md_unregister_thread(mddev->sync_thread);
3383 			mddev->sync_thread = NULL;
3384 			mddev->recovery = 0;
3385 		}
3386 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3387 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3388 		return -EBUSY;
3389 	else if (cmd_match(page, "resync"))
3390 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3391 	else if (cmd_match(page, "recover")) {
3392 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3393 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3394 	} else if (cmd_match(page, "reshape")) {
3395 		int err;
3396 		if (mddev->pers->start_reshape == NULL)
3397 			return -EINVAL;
3398 		err = mddev->pers->start_reshape(mddev);
3399 		if (err)
3400 			return err;
3401 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3402 	} else {
3403 		if (cmd_match(page, "check"))
3404 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3405 		else if (!cmd_match(page, "repair"))
3406 			return -EINVAL;
3407 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3408 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3409 	}
3410 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3411 	md_wakeup_thread(mddev->thread);
3412 	sysfs_notify_dirent(mddev->sysfs_action);
3413 	return len;
3414 }
3415 
3416 static ssize_t
3417 mismatch_cnt_show(mddev_t *mddev, char *page)
3418 {
3419 	return sprintf(page, "%llu\n",
3420 		       (unsigned long long) mddev->resync_mismatches);
3421 }
3422 
3423 static struct md_sysfs_entry md_scan_mode =
3424 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3425 
3426 
3427 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3428 
3429 static ssize_t
3430 sync_min_show(mddev_t *mddev, char *page)
3431 {
3432 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3433 		       mddev->sync_speed_min ? "local": "system");
3434 }
3435 
3436 static ssize_t
3437 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3438 {
3439 	int min;
3440 	char *e;
3441 	if (strncmp(buf, "system", 6)==0) {
3442 		mddev->sync_speed_min = 0;
3443 		return len;
3444 	}
3445 	min = simple_strtoul(buf, &e, 10);
3446 	if (buf == e || (*e && *e != '\n') || min <= 0)
3447 		return -EINVAL;
3448 	mddev->sync_speed_min = min;
3449 	return len;
3450 }
3451 
3452 static struct md_sysfs_entry md_sync_min =
3453 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3454 
3455 static ssize_t
3456 sync_max_show(mddev_t *mddev, char *page)
3457 {
3458 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3459 		       mddev->sync_speed_max ? "local": "system");
3460 }
3461 
3462 static ssize_t
3463 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3464 {
3465 	int max;
3466 	char *e;
3467 	if (strncmp(buf, "system", 6)==0) {
3468 		mddev->sync_speed_max = 0;
3469 		return len;
3470 	}
3471 	max = simple_strtoul(buf, &e, 10);
3472 	if (buf == e || (*e && *e != '\n') || max <= 0)
3473 		return -EINVAL;
3474 	mddev->sync_speed_max = max;
3475 	return len;
3476 }
3477 
3478 static struct md_sysfs_entry md_sync_max =
3479 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3480 
3481 static ssize_t
3482 degraded_show(mddev_t *mddev, char *page)
3483 {
3484 	return sprintf(page, "%d\n", mddev->degraded);
3485 }
3486 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3487 
3488 static ssize_t
3489 sync_force_parallel_show(mddev_t *mddev, char *page)
3490 {
3491 	return sprintf(page, "%d\n", mddev->parallel_resync);
3492 }
3493 
3494 static ssize_t
3495 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3496 {
3497 	long n;
3498 
3499 	if (strict_strtol(buf, 10, &n))
3500 		return -EINVAL;
3501 
3502 	if (n != 0 && n != 1)
3503 		return -EINVAL;
3504 
3505 	mddev->parallel_resync = n;
3506 
3507 	if (mddev->sync_thread)
3508 		wake_up(&resync_wait);
3509 
3510 	return len;
3511 }
3512 
3513 /* force parallel resync, even with shared block devices */
3514 static struct md_sysfs_entry md_sync_force_parallel =
3515 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3516        sync_force_parallel_show, sync_force_parallel_store);
3517 
3518 static ssize_t
3519 sync_speed_show(mddev_t *mddev, char *page)
3520 {
3521 	unsigned long resync, dt, db;
3522 	if (mddev->curr_resync == 0)
3523 		return sprintf(page, "none\n");
3524 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3525 	dt = (jiffies - mddev->resync_mark) / HZ;
3526 	if (!dt) dt++;
3527 	db = resync - mddev->resync_mark_cnt;
3528 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3529 }
3530 
3531 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3532 
3533 static ssize_t
3534 sync_completed_show(mddev_t *mddev, char *page)
3535 {
3536 	unsigned long max_sectors, resync;
3537 
3538 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3539 		return sprintf(page, "none\n");
3540 
3541 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3542 		max_sectors = mddev->resync_max_sectors;
3543 	else
3544 		max_sectors = mddev->dev_sectors;
3545 
3546 	resync = mddev->curr_resync_completed;
3547 	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
3548 }
3549 
3550 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3551 
3552 static ssize_t
3553 min_sync_show(mddev_t *mddev, char *page)
3554 {
3555 	return sprintf(page, "%llu\n",
3556 		       (unsigned long long)mddev->resync_min);
3557 }
3558 static ssize_t
3559 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3560 {
3561 	unsigned long long min;
3562 	if (strict_strtoull(buf, 10, &min))
3563 		return -EINVAL;
3564 	if (min > mddev->resync_max)
3565 		return -EINVAL;
3566 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3567 		return -EBUSY;
3568 
3569 	/* Must be a multiple of chunk_size */
3570 	if (mddev->chunk_sectors) {
3571 		sector_t temp = min;
3572 		if (sector_div(temp, mddev->chunk_sectors))
3573 			return -EINVAL;
3574 	}
3575 	mddev->resync_min = min;
3576 
3577 	return len;
3578 }
3579 
3580 static struct md_sysfs_entry md_min_sync =
3581 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3582 
3583 static ssize_t
3584 max_sync_show(mddev_t *mddev, char *page)
3585 {
3586 	if (mddev->resync_max == MaxSector)
3587 		return sprintf(page, "max\n");
3588 	else
3589 		return sprintf(page, "%llu\n",
3590 			       (unsigned long long)mddev->resync_max);
3591 }
3592 static ssize_t
3593 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3594 {
3595 	if (strncmp(buf, "max", 3) == 0)
3596 		mddev->resync_max = MaxSector;
3597 	else {
3598 		unsigned long long max;
3599 		if (strict_strtoull(buf, 10, &max))
3600 			return -EINVAL;
3601 		if (max < mddev->resync_min)
3602 			return -EINVAL;
3603 		if (max < mddev->resync_max &&
3604 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3605 			return -EBUSY;
3606 
3607 		/* Must be a multiple of chunk_size */
3608 		if (mddev->chunk_sectors) {
3609 			sector_t temp = max;
3610 			if (sector_div(temp, mddev->chunk_sectors))
3611 				return -EINVAL;
3612 		}
3613 		mddev->resync_max = max;
3614 	}
3615 	wake_up(&mddev->recovery_wait);
3616 	return len;
3617 }
3618 
3619 static struct md_sysfs_entry md_max_sync =
3620 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
3621 
3622 static ssize_t
3623 suspend_lo_show(mddev_t *mddev, char *page)
3624 {
3625 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
3626 }
3627 
3628 static ssize_t
3629 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
3630 {
3631 	char *e;
3632 	unsigned long long new = simple_strtoull(buf, &e, 10);
3633 
3634 	if (mddev->pers == NULL ||
3635 	    mddev->pers->quiesce == NULL)
3636 		return -EINVAL;
3637 	if (buf == e || (*e && *e != '\n'))
3638 		return -EINVAL;
3639 	if (new >= mddev->suspend_hi ||
3640 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
3641 		mddev->suspend_lo = new;
3642 		mddev->pers->quiesce(mddev, 2);
3643 		return len;
3644 	} else
3645 		return -EINVAL;
3646 }
3647 static struct md_sysfs_entry md_suspend_lo =
3648 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
3649 
3650 
3651 static ssize_t
3652 suspend_hi_show(mddev_t *mddev, char *page)
3653 {
3654 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
3655 }
3656 
3657 static ssize_t
3658 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
3659 {
3660 	char *e;
3661 	unsigned long long new = simple_strtoull(buf, &e, 10);
3662 
3663 	if (mddev->pers == NULL ||
3664 	    mddev->pers->quiesce == NULL)
3665 		return -EINVAL;
3666 	if (buf == e || (*e && *e != '\n'))
3667 		return -EINVAL;
3668 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
3669 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
3670 		mddev->suspend_hi = new;
3671 		mddev->pers->quiesce(mddev, 1);
3672 		mddev->pers->quiesce(mddev, 0);
3673 		return len;
3674 	} else
3675 		return -EINVAL;
3676 }
3677 static struct md_sysfs_entry md_suspend_hi =
3678 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
3679 
3680 static ssize_t
3681 reshape_position_show(mddev_t *mddev, char *page)
3682 {
3683 	if (mddev->reshape_position != MaxSector)
3684 		return sprintf(page, "%llu\n",
3685 			       (unsigned long long)mddev->reshape_position);
3686 	strcpy(page, "none\n");
3687 	return 5;
3688 }
3689 
3690 static ssize_t
3691 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
3692 {
3693 	char *e;
3694 	unsigned long long new = simple_strtoull(buf, &e, 10);
3695 	if (mddev->pers)
3696 		return -EBUSY;
3697 	if (buf == e || (*e && *e != '\n'))
3698 		return -EINVAL;
3699 	mddev->reshape_position = new;
3700 	mddev->delta_disks = 0;
3701 	mddev->new_level = mddev->level;
3702 	mddev->new_layout = mddev->layout;
3703 	mddev->new_chunk_sectors = mddev->chunk_sectors;
3704 	return len;
3705 }
3706 
3707 static struct md_sysfs_entry md_reshape_position =
3708 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
3709        reshape_position_store);
3710 
3711 static ssize_t
3712 array_size_show(mddev_t *mddev, char *page)
3713 {
3714 	if (mddev->external_size)
3715 		return sprintf(page, "%llu\n",
3716 			       (unsigned long long)mddev->array_sectors/2);
3717 	else
3718 		return sprintf(page, "default\n");
3719 }
3720 
3721 static ssize_t
3722 array_size_store(mddev_t *mddev, const char *buf, size_t len)
3723 {
3724 	sector_t sectors;
3725 
3726 	if (strncmp(buf, "default", 7) == 0) {
3727 		if (mddev->pers)
3728 			sectors = mddev->pers->size(mddev, 0, 0);
3729 		else
3730 			sectors = mddev->array_sectors;
3731 
3732 		mddev->external_size = 0;
3733 	} else {
3734 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
3735 			return -EINVAL;
3736 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
3737 			return -E2BIG;
3738 
3739 		mddev->external_size = 1;
3740 	}
3741 
3742 	mddev->array_sectors = sectors;
3743 	set_capacity(mddev->gendisk, mddev->array_sectors);
3744 	if (mddev->pers)
3745 		revalidate_disk(mddev->gendisk);
3746 
3747 	return len;
3748 }
3749 
3750 static struct md_sysfs_entry md_array_size =
3751 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
3752        array_size_store);
3753 
3754 static struct attribute *md_default_attrs[] = {
3755 	&md_level.attr,
3756 	&md_layout.attr,
3757 	&md_raid_disks.attr,
3758 	&md_chunk_size.attr,
3759 	&md_size.attr,
3760 	&md_resync_start.attr,
3761 	&md_metadata.attr,
3762 	&md_new_device.attr,
3763 	&md_safe_delay.attr,
3764 	&md_array_state.attr,
3765 	&md_reshape_position.attr,
3766 	&md_array_size.attr,
3767 	NULL,
3768 };
3769 
3770 static struct attribute *md_redundancy_attrs[] = {
3771 	&md_scan_mode.attr,
3772 	&md_mismatches.attr,
3773 	&md_sync_min.attr,
3774 	&md_sync_max.attr,
3775 	&md_sync_speed.attr,
3776 	&md_sync_force_parallel.attr,
3777 	&md_sync_completed.attr,
3778 	&md_min_sync.attr,
3779 	&md_max_sync.attr,
3780 	&md_suspend_lo.attr,
3781 	&md_suspend_hi.attr,
3782 	&md_bitmap.attr,
3783 	&md_degraded.attr,
3784 	NULL,
3785 };
3786 static struct attribute_group md_redundancy_group = {
3787 	.name = NULL,
3788 	.attrs = md_redundancy_attrs,
3789 };
3790 
3791 
3792 static ssize_t
3793 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3794 {
3795 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3796 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3797 	ssize_t rv;
3798 
3799 	if (!entry->show)
3800 		return -EIO;
3801 	rv = mddev_lock(mddev);
3802 	if (!rv) {
3803 		rv = entry->show(mddev, page);
3804 		mddev_unlock(mddev);
3805 	}
3806 	return rv;
3807 }
3808 
3809 static ssize_t
3810 md_attr_store(struct kobject *kobj, struct attribute *attr,
3811 	      const char *page, size_t length)
3812 {
3813 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3814 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3815 	ssize_t rv;
3816 
3817 	if (!entry->store)
3818 		return -EIO;
3819 	if (!capable(CAP_SYS_ADMIN))
3820 		return -EACCES;
3821 	rv = mddev_lock(mddev);
3822 	if (mddev->hold_active == UNTIL_IOCTL)
3823 		mddev->hold_active = 0;
3824 	if (!rv) {
3825 		rv = entry->store(mddev, page, length);
3826 		mddev_unlock(mddev);
3827 	}
3828 	return rv;
3829 }
3830 
3831 static void md_free(struct kobject *ko)
3832 {
3833 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
3834 
3835 	if (mddev->sysfs_state)
3836 		sysfs_put(mddev->sysfs_state);
3837 
3838 	if (mddev->gendisk) {
3839 		del_gendisk(mddev->gendisk);
3840 		put_disk(mddev->gendisk);
3841 	}
3842 	if (mddev->queue)
3843 		blk_cleanup_queue(mddev->queue);
3844 
3845 	kfree(mddev);
3846 }
3847 
3848 static struct sysfs_ops md_sysfs_ops = {
3849 	.show	= md_attr_show,
3850 	.store	= md_attr_store,
3851 };
3852 static struct kobj_type md_ktype = {
3853 	.release	= md_free,
3854 	.sysfs_ops	= &md_sysfs_ops,
3855 	.default_attrs	= md_default_attrs,
3856 };
3857 
3858 int mdp_major = 0;
3859 
3860 static void mddev_delayed_delete(struct work_struct *ws)
3861 {
3862 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
3863 
3864 	if (mddev->private == &md_redundancy_group) {
3865 		sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
3866 		if (mddev->sysfs_action)
3867 			sysfs_put(mddev->sysfs_action);
3868 		mddev->sysfs_action = NULL;
3869 		mddev->private = NULL;
3870 	}
3871 	kobject_del(&mddev->kobj);
3872 	kobject_put(&mddev->kobj);
3873 }
3874 
3875 static int md_alloc(dev_t dev, char *name)
3876 {
3877 	static DEFINE_MUTEX(disks_mutex);
3878 	mddev_t *mddev = mddev_find(dev);
3879 	struct gendisk *disk;
3880 	int partitioned;
3881 	int shift;
3882 	int unit;
3883 	int error;
3884 
3885 	if (!mddev)
3886 		return -ENODEV;
3887 
3888 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
3889 	shift = partitioned ? MdpMinorShift : 0;
3890 	unit = MINOR(mddev->unit) >> shift;
3891 
3892 	/* wait for any previous instance if this device
3893 	 * to be completed removed (mddev_delayed_delete).
3894 	 */
3895 	flush_scheduled_work();
3896 
3897 	mutex_lock(&disks_mutex);
3898 	error = -EEXIST;
3899 	if (mddev->gendisk)
3900 		goto abort;
3901 
3902 	if (name) {
3903 		/* Need to ensure that 'name' is not a duplicate.
3904 		 */
3905 		mddev_t *mddev2;
3906 		spin_lock(&all_mddevs_lock);
3907 
3908 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
3909 			if (mddev2->gendisk &&
3910 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
3911 				spin_unlock(&all_mddevs_lock);
3912 				goto abort;
3913 			}
3914 		spin_unlock(&all_mddevs_lock);
3915 	}
3916 
3917 	error = -ENOMEM;
3918 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
3919 	if (!mddev->queue)
3920 		goto abort;
3921 	mddev->queue->queuedata = mddev;
3922 
3923 	/* Can be unlocked because the queue is new: no concurrency */
3924 	queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
3925 
3926 	blk_queue_make_request(mddev->queue, md_make_request);
3927 
3928 	disk = alloc_disk(1 << shift);
3929 	if (!disk) {
3930 		blk_cleanup_queue(mddev->queue);
3931 		mddev->queue = NULL;
3932 		goto abort;
3933 	}
3934 	disk->major = MAJOR(mddev->unit);
3935 	disk->first_minor = unit << shift;
3936 	if (name)
3937 		strcpy(disk->disk_name, name);
3938 	else if (partitioned)
3939 		sprintf(disk->disk_name, "md_d%d", unit);
3940 	else
3941 		sprintf(disk->disk_name, "md%d", unit);
3942 	disk->fops = &md_fops;
3943 	disk->private_data = mddev;
3944 	disk->queue = mddev->queue;
3945 	/* Allow extended partitions.  This makes the
3946 	 * 'mdp' device redundant, but we can't really
3947 	 * remove it now.
3948 	 */
3949 	disk->flags |= GENHD_FL_EXT_DEVT;
3950 	add_disk(disk);
3951 	mddev->gendisk = disk;
3952 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
3953 				     &disk_to_dev(disk)->kobj, "%s", "md");
3954 	if (error) {
3955 		/* This isn't possible, but as kobject_init_and_add is marked
3956 		 * __must_check, we must do something with the result
3957 		 */
3958 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
3959 		       disk->disk_name);
3960 		error = 0;
3961 	}
3962  abort:
3963 	mutex_unlock(&disks_mutex);
3964 	if (!error) {
3965 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
3966 		mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
3967 	}
3968 	mddev_put(mddev);
3969 	return error;
3970 }
3971 
3972 static struct kobject *md_probe(dev_t dev, int *part, void *data)
3973 {
3974 	md_alloc(dev, NULL);
3975 	return NULL;
3976 }
3977 
3978 static int add_named_array(const char *val, struct kernel_param *kp)
3979 {
3980 	/* val must be "md_*" where * is not all digits.
3981 	 * We allocate an array with a large free minor number, and
3982 	 * set the name to val.  val must not already be an active name.
3983 	 */
3984 	int len = strlen(val);
3985 	char buf[DISK_NAME_LEN];
3986 
3987 	while (len && val[len-1] == '\n')
3988 		len--;
3989 	if (len >= DISK_NAME_LEN)
3990 		return -E2BIG;
3991 	strlcpy(buf, val, len+1);
3992 	if (strncmp(buf, "md_", 3) != 0)
3993 		return -EINVAL;
3994 	return md_alloc(0, buf);
3995 }
3996 
3997 static void md_safemode_timeout(unsigned long data)
3998 {
3999 	mddev_t *mddev = (mddev_t *) data;
4000 
4001 	if (!atomic_read(&mddev->writes_pending)) {
4002 		mddev->safemode = 1;
4003 		if (mddev->external)
4004 			sysfs_notify_dirent(mddev->sysfs_state);
4005 	}
4006 	md_wakeup_thread(mddev->thread);
4007 }
4008 
4009 static int start_dirty_degraded;
4010 
4011 static int do_md_run(mddev_t * mddev)
4012 {
4013 	int err;
4014 	mdk_rdev_t *rdev;
4015 	struct gendisk *disk;
4016 	struct mdk_personality *pers;
4017 
4018 	if (list_empty(&mddev->disks))
4019 		/* cannot run an array with no devices.. */
4020 		return -EINVAL;
4021 
4022 	if (mddev->pers)
4023 		return -EBUSY;
4024 
4025 	/*
4026 	 * Analyze all RAID superblock(s)
4027 	 */
4028 	if (!mddev->raid_disks) {
4029 		if (!mddev->persistent)
4030 			return -EINVAL;
4031 		analyze_sbs(mddev);
4032 	}
4033 
4034 	if (mddev->level != LEVEL_NONE)
4035 		request_module("md-level-%d", mddev->level);
4036 	else if (mddev->clevel[0])
4037 		request_module("md-%s", mddev->clevel);
4038 
4039 	/*
4040 	 * Drop all container device buffers, from now on
4041 	 * the only valid external interface is through the md
4042 	 * device.
4043 	 */
4044 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4045 		if (test_bit(Faulty, &rdev->flags))
4046 			continue;
4047 		sync_blockdev(rdev->bdev);
4048 		invalidate_bdev(rdev->bdev);
4049 
4050 		/* perform some consistency tests on the device.
4051 		 * We don't want the data to overlap the metadata,
4052 		 * Internal Bitmap issues have been handled elsewhere.
4053 		 */
4054 		if (rdev->data_offset < rdev->sb_start) {
4055 			if (mddev->dev_sectors &&
4056 			    rdev->data_offset + mddev->dev_sectors
4057 			    > rdev->sb_start) {
4058 				printk("md: %s: data overlaps metadata\n",
4059 				       mdname(mddev));
4060 				return -EINVAL;
4061 			}
4062 		} else {
4063 			if (rdev->sb_start + rdev->sb_size/512
4064 			    > rdev->data_offset) {
4065 				printk("md: %s: metadata overlaps data\n",
4066 				       mdname(mddev));
4067 				return -EINVAL;
4068 			}
4069 		}
4070 		sysfs_notify_dirent(rdev->sysfs_state);
4071 	}
4072 
4073 	md_probe(mddev->unit, NULL, NULL);
4074 	disk = mddev->gendisk;
4075 	if (!disk)
4076 		return -ENOMEM;
4077 
4078 	spin_lock(&pers_lock);
4079 	pers = find_pers(mddev->level, mddev->clevel);
4080 	if (!pers || !try_module_get(pers->owner)) {
4081 		spin_unlock(&pers_lock);
4082 		if (mddev->level != LEVEL_NONE)
4083 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4084 			       mddev->level);
4085 		else
4086 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4087 			       mddev->clevel);
4088 		return -EINVAL;
4089 	}
4090 	mddev->pers = pers;
4091 	spin_unlock(&pers_lock);
4092 	if (mddev->level != pers->level) {
4093 		mddev->level = pers->level;
4094 		mddev->new_level = pers->level;
4095 	}
4096 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4097 
4098 	if (mddev->reshape_position != MaxSector &&
4099 	    pers->start_reshape == NULL) {
4100 		/* This personality cannot handle reshaping... */
4101 		mddev->pers = NULL;
4102 		module_put(pers->owner);
4103 		return -EINVAL;
4104 	}
4105 
4106 	if (pers->sync_request) {
4107 		/* Warn if this is a potentially silly
4108 		 * configuration.
4109 		 */
4110 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4111 		mdk_rdev_t *rdev2;
4112 		int warned = 0;
4113 
4114 		list_for_each_entry(rdev, &mddev->disks, same_set)
4115 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4116 				if (rdev < rdev2 &&
4117 				    rdev->bdev->bd_contains ==
4118 				    rdev2->bdev->bd_contains) {
4119 					printk(KERN_WARNING
4120 					       "%s: WARNING: %s appears to be"
4121 					       " on the same physical disk as"
4122 					       " %s.\n",
4123 					       mdname(mddev),
4124 					       bdevname(rdev->bdev,b),
4125 					       bdevname(rdev2->bdev,b2));
4126 					warned = 1;
4127 				}
4128 			}
4129 
4130 		if (warned)
4131 			printk(KERN_WARNING
4132 			       "True protection against single-disk"
4133 			       " failure might be compromised.\n");
4134 	}
4135 
4136 	mddev->recovery = 0;
4137 	/* may be over-ridden by personality */
4138 	mddev->resync_max_sectors = mddev->dev_sectors;
4139 
4140 	mddev->barriers_work = 1;
4141 	mddev->ok_start_degraded = start_dirty_degraded;
4142 
4143 	if (start_readonly)
4144 		mddev->ro = 2; /* read-only, but switch on first write */
4145 
4146 	err = mddev->pers->run(mddev);
4147 	if (err)
4148 		printk(KERN_ERR "md: pers->run() failed ...\n");
4149 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4150 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4151 			  " but 'external_size' not in effect?\n", __func__);
4152 		printk(KERN_ERR
4153 		       "md: invalid array_size %llu > default size %llu\n",
4154 		       (unsigned long long)mddev->array_sectors / 2,
4155 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4156 		err = -EINVAL;
4157 		mddev->pers->stop(mddev);
4158 	}
4159 	if (err == 0 && mddev->pers->sync_request) {
4160 		err = bitmap_create(mddev);
4161 		if (err) {
4162 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4163 			       mdname(mddev), err);
4164 			mddev->pers->stop(mddev);
4165 		}
4166 	}
4167 	if (err) {
4168 		module_put(mddev->pers->owner);
4169 		mddev->pers = NULL;
4170 		bitmap_destroy(mddev);
4171 		return err;
4172 	}
4173 	if (mddev->pers->sync_request) {
4174 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4175 			printk(KERN_WARNING
4176 			       "md: cannot register extra attributes for %s\n",
4177 			       mdname(mddev));
4178 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
4179 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4180 		mddev->ro = 0;
4181 
4182  	atomic_set(&mddev->writes_pending,0);
4183 	mddev->safemode = 0;
4184 	mddev->safemode_timer.function = md_safemode_timeout;
4185 	mddev->safemode_timer.data = (unsigned long) mddev;
4186 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4187 	mddev->in_sync = 1;
4188 
4189 	list_for_each_entry(rdev, &mddev->disks, same_set)
4190 		if (rdev->raid_disk >= 0) {
4191 			char nm[20];
4192 			sprintf(nm, "rd%d", rdev->raid_disk);
4193 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
4194 				printk("md: cannot register %s for %s\n",
4195 				       nm, mdname(mddev));
4196 		}
4197 
4198 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4199 
4200 	if (mddev->flags)
4201 		md_update_sb(mddev, 0);
4202 
4203 	set_capacity(disk, mddev->array_sectors);
4204 
4205 	/* If there is a partially-recovered drive we need to
4206 	 * start recovery here.  If we leave it to md_check_recovery,
4207 	 * it will remove the drives and not do the right thing
4208 	 */
4209 	if (mddev->degraded && !mddev->sync_thread) {
4210 		int spares = 0;
4211 		list_for_each_entry(rdev, &mddev->disks, same_set)
4212 			if (rdev->raid_disk >= 0 &&
4213 			    !test_bit(In_sync, &rdev->flags) &&
4214 			    !test_bit(Faulty, &rdev->flags))
4215 				/* complete an interrupted recovery */
4216 				spares++;
4217 		if (spares && mddev->pers->sync_request) {
4218 			mddev->recovery = 0;
4219 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4220 			mddev->sync_thread = md_register_thread(md_do_sync,
4221 								mddev,
4222 								"%s_resync");
4223 			if (!mddev->sync_thread) {
4224 				printk(KERN_ERR "%s: could not start resync"
4225 				       " thread...\n",
4226 				       mdname(mddev));
4227 				/* leave the spares where they are, it shouldn't hurt */
4228 				mddev->recovery = 0;
4229 			}
4230 		}
4231 	}
4232 	md_wakeup_thread(mddev->thread);
4233 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4234 
4235 	revalidate_disk(mddev->gendisk);
4236 	mddev->changed = 1;
4237 	md_new_event(mddev);
4238 	sysfs_notify_dirent(mddev->sysfs_state);
4239 	if (mddev->sysfs_action)
4240 		sysfs_notify_dirent(mddev->sysfs_action);
4241 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4242 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4243 	return 0;
4244 }
4245 
4246 static int restart_array(mddev_t *mddev)
4247 {
4248 	struct gendisk *disk = mddev->gendisk;
4249 
4250 	/* Complain if it has no devices */
4251 	if (list_empty(&mddev->disks))
4252 		return -ENXIO;
4253 	if (!mddev->pers)
4254 		return -EINVAL;
4255 	if (!mddev->ro)
4256 		return -EBUSY;
4257 	mddev->safemode = 0;
4258 	mddev->ro = 0;
4259 	set_disk_ro(disk, 0);
4260 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4261 		mdname(mddev));
4262 	/* Kick recovery or resync if necessary */
4263 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4264 	md_wakeup_thread(mddev->thread);
4265 	md_wakeup_thread(mddev->sync_thread);
4266 	sysfs_notify_dirent(mddev->sysfs_state);
4267 	return 0;
4268 }
4269 
4270 /* similar to deny_write_access, but accounts for our holding a reference
4271  * to the file ourselves */
4272 static int deny_bitmap_write_access(struct file * file)
4273 {
4274 	struct inode *inode = file->f_mapping->host;
4275 
4276 	spin_lock(&inode->i_lock);
4277 	if (atomic_read(&inode->i_writecount) > 1) {
4278 		spin_unlock(&inode->i_lock);
4279 		return -ETXTBSY;
4280 	}
4281 	atomic_set(&inode->i_writecount, -1);
4282 	spin_unlock(&inode->i_lock);
4283 
4284 	return 0;
4285 }
4286 
4287 static void restore_bitmap_write_access(struct file *file)
4288 {
4289 	struct inode *inode = file->f_mapping->host;
4290 
4291 	spin_lock(&inode->i_lock);
4292 	atomic_set(&inode->i_writecount, 1);
4293 	spin_unlock(&inode->i_lock);
4294 }
4295 
4296 /* mode:
4297  *   0 - completely stop and dis-assemble array
4298  *   1 - switch to readonly
4299  *   2 - stop but do not disassemble array
4300  */
4301 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4302 {
4303 	int err = 0;
4304 	struct gendisk *disk = mddev->gendisk;
4305 	mdk_rdev_t *rdev;
4306 
4307 	if (atomic_read(&mddev->openers) > is_open) {
4308 		printk("md: %s still in use.\n",mdname(mddev));
4309 		return -EBUSY;
4310 	}
4311 
4312 	if (mddev->pers) {
4313 
4314 		if (mddev->sync_thread) {
4315 			set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4316 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4317 			md_unregister_thread(mddev->sync_thread);
4318 			mddev->sync_thread = NULL;
4319 		}
4320 
4321 		del_timer_sync(&mddev->safemode_timer);
4322 
4323 		switch(mode) {
4324 		case 1: /* readonly */
4325 			err  = -ENXIO;
4326 			if (mddev->ro==1)
4327 				goto out;
4328 			mddev->ro = 1;
4329 			break;
4330 		case 0: /* disassemble */
4331 		case 2: /* stop */
4332 			bitmap_flush(mddev);
4333 			md_super_wait(mddev);
4334 			if (mddev->ro)
4335 				set_disk_ro(disk, 0);
4336 
4337 			mddev->pers->stop(mddev);
4338 			mddev->queue->merge_bvec_fn = NULL;
4339 			mddev->queue->unplug_fn = NULL;
4340 			mddev->queue->backing_dev_info.congested_fn = NULL;
4341 			module_put(mddev->pers->owner);
4342 			if (mddev->pers->sync_request)
4343 				mddev->private = &md_redundancy_group;
4344 			mddev->pers = NULL;
4345 			/* tell userspace to handle 'inactive' */
4346 			sysfs_notify_dirent(mddev->sysfs_state);
4347 
4348 			list_for_each_entry(rdev, &mddev->disks, same_set)
4349 				if (rdev->raid_disk >= 0) {
4350 					char nm[20];
4351 					sprintf(nm, "rd%d", rdev->raid_disk);
4352 					sysfs_remove_link(&mddev->kobj, nm);
4353 				}
4354 
4355 			set_capacity(disk, 0);
4356 			mddev->changed = 1;
4357 
4358 			if (mddev->ro)
4359 				mddev->ro = 0;
4360 		}
4361 		if (!mddev->in_sync || mddev->flags) {
4362 			/* mark array as shutdown cleanly */
4363 			mddev->in_sync = 1;
4364 			md_update_sb(mddev, 1);
4365 		}
4366 		if (mode == 1)
4367 			set_disk_ro(disk, 1);
4368 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4369 	}
4370 
4371 	/*
4372 	 * Free resources if final stop
4373 	 */
4374 	if (mode == 0) {
4375 
4376 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4377 
4378 		bitmap_destroy(mddev);
4379 		if (mddev->bitmap_file) {
4380 			restore_bitmap_write_access(mddev->bitmap_file);
4381 			fput(mddev->bitmap_file);
4382 			mddev->bitmap_file = NULL;
4383 		}
4384 		mddev->bitmap_offset = 0;
4385 
4386 		/* make sure all md_delayed_delete calls have finished */
4387 		flush_scheduled_work();
4388 
4389 		export_array(mddev);
4390 
4391 		mddev->array_sectors = 0;
4392 		mddev->external_size = 0;
4393 		mddev->dev_sectors = 0;
4394 		mddev->raid_disks = 0;
4395 		mddev->recovery_cp = 0;
4396 		mddev->resync_min = 0;
4397 		mddev->resync_max = MaxSector;
4398 		mddev->reshape_position = MaxSector;
4399 		mddev->external = 0;
4400 		mddev->persistent = 0;
4401 		mddev->level = LEVEL_NONE;
4402 		mddev->clevel[0] = 0;
4403 		mddev->flags = 0;
4404 		mddev->ro = 0;
4405 		mddev->metadata_type[0] = 0;
4406 		mddev->chunk_sectors = 0;
4407 		mddev->ctime = mddev->utime = 0;
4408 		mddev->layout = 0;
4409 		mddev->max_disks = 0;
4410 		mddev->events = 0;
4411 		mddev->delta_disks = 0;
4412 		mddev->new_level = LEVEL_NONE;
4413 		mddev->new_layout = 0;
4414 		mddev->new_chunk_sectors = 0;
4415 		mddev->curr_resync = 0;
4416 		mddev->resync_mismatches = 0;
4417 		mddev->suspend_lo = mddev->suspend_hi = 0;
4418 		mddev->sync_speed_min = mddev->sync_speed_max = 0;
4419 		mddev->recovery = 0;
4420 		mddev->in_sync = 0;
4421 		mddev->changed = 0;
4422 		mddev->degraded = 0;
4423 		mddev->barriers_work = 0;
4424 		mddev->safemode = 0;
4425 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4426 		if (mddev->hold_active == UNTIL_STOP)
4427 			mddev->hold_active = 0;
4428 
4429 	} else if (mddev->pers)
4430 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
4431 			mdname(mddev));
4432 	err = 0;
4433 	blk_integrity_unregister(disk);
4434 	md_new_event(mddev);
4435 	sysfs_notify_dirent(mddev->sysfs_state);
4436 out:
4437 	return err;
4438 }
4439 
4440 #ifndef MODULE
4441 static void autorun_array(mddev_t *mddev)
4442 {
4443 	mdk_rdev_t *rdev;
4444 	int err;
4445 
4446 	if (list_empty(&mddev->disks))
4447 		return;
4448 
4449 	printk(KERN_INFO "md: running: ");
4450 
4451 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4452 		char b[BDEVNAME_SIZE];
4453 		printk("<%s>", bdevname(rdev->bdev,b));
4454 	}
4455 	printk("\n");
4456 
4457 	err = do_md_run(mddev);
4458 	if (err) {
4459 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4460 		do_md_stop(mddev, 0, 0);
4461 	}
4462 }
4463 
4464 /*
4465  * lets try to run arrays based on all disks that have arrived
4466  * until now. (those are in pending_raid_disks)
4467  *
4468  * the method: pick the first pending disk, collect all disks with
4469  * the same UUID, remove all from the pending list and put them into
4470  * the 'same_array' list. Then order this list based on superblock
4471  * update time (freshest comes first), kick out 'old' disks and
4472  * compare superblocks. If everything's fine then run it.
4473  *
4474  * If "unit" is allocated, then bump its reference count
4475  */
4476 static void autorun_devices(int part)
4477 {
4478 	mdk_rdev_t *rdev0, *rdev, *tmp;
4479 	mddev_t *mddev;
4480 	char b[BDEVNAME_SIZE];
4481 
4482 	printk(KERN_INFO "md: autorun ...\n");
4483 	while (!list_empty(&pending_raid_disks)) {
4484 		int unit;
4485 		dev_t dev;
4486 		LIST_HEAD(candidates);
4487 		rdev0 = list_entry(pending_raid_disks.next,
4488 					 mdk_rdev_t, same_set);
4489 
4490 		printk(KERN_INFO "md: considering %s ...\n",
4491 			bdevname(rdev0->bdev,b));
4492 		INIT_LIST_HEAD(&candidates);
4493 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4494 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4495 				printk(KERN_INFO "md:  adding %s ...\n",
4496 					bdevname(rdev->bdev,b));
4497 				list_move(&rdev->same_set, &candidates);
4498 			}
4499 		/*
4500 		 * now we have a set of devices, with all of them having
4501 		 * mostly sane superblocks. It's time to allocate the
4502 		 * mddev.
4503 		 */
4504 		if (part) {
4505 			dev = MKDEV(mdp_major,
4506 				    rdev0->preferred_minor << MdpMinorShift);
4507 			unit = MINOR(dev) >> MdpMinorShift;
4508 		} else {
4509 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4510 			unit = MINOR(dev);
4511 		}
4512 		if (rdev0->preferred_minor != unit) {
4513 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4514 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4515 			break;
4516 		}
4517 
4518 		md_probe(dev, NULL, NULL);
4519 		mddev = mddev_find(dev);
4520 		if (!mddev || !mddev->gendisk) {
4521 			if (mddev)
4522 				mddev_put(mddev);
4523 			printk(KERN_ERR
4524 				"md: cannot allocate memory for md drive.\n");
4525 			break;
4526 		}
4527 		if (mddev_lock(mddev))
4528 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4529 			       mdname(mddev));
4530 		else if (mddev->raid_disks || mddev->major_version
4531 			 || !list_empty(&mddev->disks)) {
4532 			printk(KERN_WARNING
4533 				"md: %s already running, cannot run %s\n",
4534 				mdname(mddev), bdevname(rdev0->bdev,b));
4535 			mddev_unlock(mddev);
4536 		} else {
4537 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4538 			mddev->persistent = 1;
4539 			rdev_for_each_list(rdev, tmp, &candidates) {
4540 				list_del_init(&rdev->same_set);
4541 				if (bind_rdev_to_array(rdev, mddev))
4542 					export_rdev(rdev);
4543 			}
4544 			autorun_array(mddev);
4545 			mddev_unlock(mddev);
4546 		}
4547 		/* on success, candidates will be empty, on error
4548 		 * it won't...
4549 		 */
4550 		rdev_for_each_list(rdev, tmp, &candidates) {
4551 			list_del_init(&rdev->same_set);
4552 			export_rdev(rdev);
4553 		}
4554 		mddev_put(mddev);
4555 	}
4556 	printk(KERN_INFO "md: ... autorun DONE.\n");
4557 }
4558 #endif /* !MODULE */
4559 
4560 static int get_version(void __user * arg)
4561 {
4562 	mdu_version_t ver;
4563 
4564 	ver.major = MD_MAJOR_VERSION;
4565 	ver.minor = MD_MINOR_VERSION;
4566 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4567 
4568 	if (copy_to_user(arg, &ver, sizeof(ver)))
4569 		return -EFAULT;
4570 
4571 	return 0;
4572 }
4573 
4574 static int get_array_info(mddev_t * mddev, void __user * arg)
4575 {
4576 	mdu_array_info_t info;
4577 	int nr,working,active,failed,spare;
4578 	mdk_rdev_t *rdev;
4579 
4580 	nr=working=active=failed=spare=0;
4581 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4582 		nr++;
4583 		if (test_bit(Faulty, &rdev->flags))
4584 			failed++;
4585 		else {
4586 			working++;
4587 			if (test_bit(In_sync, &rdev->flags))
4588 				active++;
4589 			else
4590 				spare++;
4591 		}
4592 	}
4593 
4594 	info.major_version = mddev->major_version;
4595 	info.minor_version = mddev->minor_version;
4596 	info.patch_version = MD_PATCHLEVEL_VERSION;
4597 	info.ctime         = mddev->ctime;
4598 	info.level         = mddev->level;
4599 	info.size          = mddev->dev_sectors / 2;
4600 	if (info.size != mddev->dev_sectors / 2) /* overflow */
4601 		info.size = -1;
4602 	info.nr_disks      = nr;
4603 	info.raid_disks    = mddev->raid_disks;
4604 	info.md_minor      = mddev->md_minor;
4605 	info.not_persistent= !mddev->persistent;
4606 
4607 	info.utime         = mddev->utime;
4608 	info.state         = 0;
4609 	if (mddev->in_sync)
4610 		info.state = (1<<MD_SB_CLEAN);
4611 	if (mddev->bitmap && mddev->bitmap_offset)
4612 		info.state = (1<<MD_SB_BITMAP_PRESENT);
4613 	info.active_disks  = active;
4614 	info.working_disks = working;
4615 	info.failed_disks  = failed;
4616 	info.spare_disks   = spare;
4617 
4618 	info.layout        = mddev->layout;
4619 	info.chunk_size    = mddev->chunk_sectors << 9;
4620 
4621 	if (copy_to_user(arg, &info, sizeof(info)))
4622 		return -EFAULT;
4623 
4624 	return 0;
4625 }
4626 
4627 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
4628 {
4629 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
4630 	char *ptr, *buf = NULL;
4631 	int err = -ENOMEM;
4632 
4633 	if (md_allow_write(mddev))
4634 		file = kmalloc(sizeof(*file), GFP_NOIO);
4635 	else
4636 		file = kmalloc(sizeof(*file), GFP_KERNEL);
4637 
4638 	if (!file)
4639 		goto out;
4640 
4641 	/* bitmap disabled, zero the first byte and copy out */
4642 	if (!mddev->bitmap || !mddev->bitmap->file) {
4643 		file->pathname[0] = '\0';
4644 		goto copy_out;
4645 	}
4646 
4647 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
4648 	if (!buf)
4649 		goto out;
4650 
4651 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
4652 	if (IS_ERR(ptr))
4653 		goto out;
4654 
4655 	strcpy(file->pathname, ptr);
4656 
4657 copy_out:
4658 	err = 0;
4659 	if (copy_to_user(arg, file, sizeof(*file)))
4660 		err = -EFAULT;
4661 out:
4662 	kfree(buf);
4663 	kfree(file);
4664 	return err;
4665 }
4666 
4667 static int get_disk_info(mddev_t * mddev, void __user * arg)
4668 {
4669 	mdu_disk_info_t info;
4670 	mdk_rdev_t *rdev;
4671 
4672 	if (copy_from_user(&info, arg, sizeof(info)))
4673 		return -EFAULT;
4674 
4675 	rdev = find_rdev_nr(mddev, info.number);
4676 	if (rdev) {
4677 		info.major = MAJOR(rdev->bdev->bd_dev);
4678 		info.minor = MINOR(rdev->bdev->bd_dev);
4679 		info.raid_disk = rdev->raid_disk;
4680 		info.state = 0;
4681 		if (test_bit(Faulty, &rdev->flags))
4682 			info.state |= (1<<MD_DISK_FAULTY);
4683 		else if (test_bit(In_sync, &rdev->flags)) {
4684 			info.state |= (1<<MD_DISK_ACTIVE);
4685 			info.state |= (1<<MD_DISK_SYNC);
4686 		}
4687 		if (test_bit(WriteMostly, &rdev->flags))
4688 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
4689 	} else {
4690 		info.major = info.minor = 0;
4691 		info.raid_disk = -1;
4692 		info.state = (1<<MD_DISK_REMOVED);
4693 	}
4694 
4695 	if (copy_to_user(arg, &info, sizeof(info)))
4696 		return -EFAULT;
4697 
4698 	return 0;
4699 }
4700 
4701 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
4702 {
4703 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4704 	mdk_rdev_t *rdev;
4705 	dev_t dev = MKDEV(info->major,info->minor);
4706 
4707 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
4708 		return -EOVERFLOW;
4709 
4710 	if (!mddev->raid_disks) {
4711 		int err;
4712 		/* expecting a device which has a superblock */
4713 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
4714 		if (IS_ERR(rdev)) {
4715 			printk(KERN_WARNING
4716 				"md: md_import_device returned %ld\n",
4717 				PTR_ERR(rdev));
4718 			return PTR_ERR(rdev);
4719 		}
4720 		if (!list_empty(&mddev->disks)) {
4721 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
4722 							mdk_rdev_t, same_set);
4723 			int err = super_types[mddev->major_version]
4724 				.load_super(rdev, rdev0, mddev->minor_version);
4725 			if (err < 0) {
4726 				printk(KERN_WARNING
4727 					"md: %s has different UUID to %s\n",
4728 					bdevname(rdev->bdev,b),
4729 					bdevname(rdev0->bdev,b2));
4730 				export_rdev(rdev);
4731 				return -EINVAL;
4732 			}
4733 		}
4734 		err = bind_rdev_to_array(rdev, mddev);
4735 		if (err)
4736 			export_rdev(rdev);
4737 		return err;
4738 	}
4739 
4740 	/*
4741 	 * add_new_disk can be used once the array is assembled
4742 	 * to add "hot spares".  They must already have a superblock
4743 	 * written
4744 	 */
4745 	if (mddev->pers) {
4746 		int err;
4747 		if (!mddev->pers->hot_add_disk) {
4748 			printk(KERN_WARNING
4749 				"%s: personality does not support diskops!\n",
4750 			       mdname(mddev));
4751 			return -EINVAL;
4752 		}
4753 		if (mddev->persistent)
4754 			rdev = md_import_device(dev, mddev->major_version,
4755 						mddev->minor_version);
4756 		else
4757 			rdev = md_import_device(dev, -1, -1);
4758 		if (IS_ERR(rdev)) {
4759 			printk(KERN_WARNING
4760 				"md: md_import_device returned %ld\n",
4761 				PTR_ERR(rdev));
4762 			return PTR_ERR(rdev);
4763 		}
4764 		/* set save_raid_disk if appropriate */
4765 		if (!mddev->persistent) {
4766 			if (info->state & (1<<MD_DISK_SYNC)  &&
4767 			    info->raid_disk < mddev->raid_disks)
4768 				rdev->raid_disk = info->raid_disk;
4769 			else
4770 				rdev->raid_disk = -1;
4771 		} else
4772 			super_types[mddev->major_version].
4773 				validate_super(mddev, rdev);
4774 		rdev->saved_raid_disk = rdev->raid_disk;
4775 
4776 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
4777 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4778 			set_bit(WriteMostly, &rdev->flags);
4779 		else
4780 			clear_bit(WriteMostly, &rdev->flags);
4781 
4782 		rdev->raid_disk = -1;
4783 		err = bind_rdev_to_array(rdev, mddev);
4784 		if (!err && !mddev->pers->hot_remove_disk) {
4785 			/* If there is hot_add_disk but no hot_remove_disk
4786 			 * then added disks for geometry changes,
4787 			 * and should be added immediately.
4788 			 */
4789 			super_types[mddev->major_version].
4790 				validate_super(mddev, rdev);
4791 			err = mddev->pers->hot_add_disk(mddev, rdev);
4792 			if (err)
4793 				unbind_rdev_from_array(rdev);
4794 		}
4795 		if (err)
4796 			export_rdev(rdev);
4797 		else
4798 			sysfs_notify_dirent(rdev->sysfs_state);
4799 
4800 		md_update_sb(mddev, 1);
4801 		if (mddev->degraded)
4802 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4803 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4804 		md_wakeup_thread(mddev->thread);
4805 		return err;
4806 	}
4807 
4808 	/* otherwise, add_new_disk is only allowed
4809 	 * for major_version==0 superblocks
4810 	 */
4811 	if (mddev->major_version != 0) {
4812 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
4813 		       mdname(mddev));
4814 		return -EINVAL;
4815 	}
4816 
4817 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
4818 		int err;
4819 		rdev = md_import_device(dev, -1, 0);
4820 		if (IS_ERR(rdev)) {
4821 			printk(KERN_WARNING
4822 				"md: error, md_import_device() returned %ld\n",
4823 				PTR_ERR(rdev));
4824 			return PTR_ERR(rdev);
4825 		}
4826 		rdev->desc_nr = info->number;
4827 		if (info->raid_disk < mddev->raid_disks)
4828 			rdev->raid_disk = info->raid_disk;
4829 		else
4830 			rdev->raid_disk = -1;
4831 
4832 		if (rdev->raid_disk < mddev->raid_disks)
4833 			if (info->state & (1<<MD_DISK_SYNC))
4834 				set_bit(In_sync, &rdev->flags);
4835 
4836 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4837 			set_bit(WriteMostly, &rdev->flags);
4838 
4839 		if (!mddev->persistent) {
4840 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
4841 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4842 		} else
4843 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4844 		rdev->sectors = rdev->sb_start;
4845 
4846 		err = bind_rdev_to_array(rdev, mddev);
4847 		if (err) {
4848 			export_rdev(rdev);
4849 			return err;
4850 		}
4851 	}
4852 
4853 	return 0;
4854 }
4855 
4856 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
4857 {
4858 	char b[BDEVNAME_SIZE];
4859 	mdk_rdev_t *rdev;
4860 
4861 	rdev = find_rdev(mddev, dev);
4862 	if (!rdev)
4863 		return -ENXIO;
4864 
4865 	if (rdev->raid_disk >= 0)
4866 		goto busy;
4867 
4868 	kick_rdev_from_array(rdev);
4869 	md_update_sb(mddev, 1);
4870 	md_new_event(mddev);
4871 
4872 	return 0;
4873 busy:
4874 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
4875 		bdevname(rdev->bdev,b), mdname(mddev));
4876 	return -EBUSY;
4877 }
4878 
4879 static int hot_add_disk(mddev_t * mddev, dev_t dev)
4880 {
4881 	char b[BDEVNAME_SIZE];
4882 	int err;
4883 	mdk_rdev_t *rdev;
4884 
4885 	if (!mddev->pers)
4886 		return -ENODEV;
4887 
4888 	if (mddev->major_version != 0) {
4889 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
4890 			" version-0 superblocks.\n",
4891 			mdname(mddev));
4892 		return -EINVAL;
4893 	}
4894 	if (!mddev->pers->hot_add_disk) {
4895 		printk(KERN_WARNING
4896 			"%s: personality does not support diskops!\n",
4897 			mdname(mddev));
4898 		return -EINVAL;
4899 	}
4900 
4901 	rdev = md_import_device(dev, -1, 0);
4902 	if (IS_ERR(rdev)) {
4903 		printk(KERN_WARNING
4904 			"md: error, md_import_device() returned %ld\n",
4905 			PTR_ERR(rdev));
4906 		return -EINVAL;
4907 	}
4908 
4909 	if (mddev->persistent)
4910 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4911 	else
4912 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4913 
4914 	rdev->sectors = rdev->sb_start;
4915 
4916 	if (test_bit(Faulty, &rdev->flags)) {
4917 		printk(KERN_WARNING
4918 			"md: can not hot-add faulty %s disk to %s!\n",
4919 			bdevname(rdev->bdev,b), mdname(mddev));
4920 		err = -EINVAL;
4921 		goto abort_export;
4922 	}
4923 	clear_bit(In_sync, &rdev->flags);
4924 	rdev->desc_nr = -1;
4925 	rdev->saved_raid_disk = -1;
4926 	err = bind_rdev_to_array(rdev, mddev);
4927 	if (err)
4928 		goto abort_export;
4929 
4930 	/*
4931 	 * The rest should better be atomic, we can have disk failures
4932 	 * noticed in interrupt contexts ...
4933 	 */
4934 
4935 	rdev->raid_disk = -1;
4936 
4937 	md_update_sb(mddev, 1);
4938 
4939 	/*
4940 	 * Kick recovery, maybe this spare has to be added to the
4941 	 * array immediately.
4942 	 */
4943 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4944 	md_wakeup_thread(mddev->thread);
4945 	md_new_event(mddev);
4946 	return 0;
4947 
4948 abort_export:
4949 	export_rdev(rdev);
4950 	return err;
4951 }
4952 
4953 static int set_bitmap_file(mddev_t *mddev, int fd)
4954 {
4955 	int err;
4956 
4957 	if (mddev->pers) {
4958 		if (!mddev->pers->quiesce)
4959 			return -EBUSY;
4960 		if (mddev->recovery || mddev->sync_thread)
4961 			return -EBUSY;
4962 		/* we should be able to change the bitmap.. */
4963 	}
4964 
4965 
4966 	if (fd >= 0) {
4967 		if (mddev->bitmap)
4968 			return -EEXIST; /* cannot add when bitmap is present */
4969 		mddev->bitmap_file = fget(fd);
4970 
4971 		if (mddev->bitmap_file == NULL) {
4972 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
4973 			       mdname(mddev));
4974 			return -EBADF;
4975 		}
4976 
4977 		err = deny_bitmap_write_access(mddev->bitmap_file);
4978 		if (err) {
4979 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
4980 			       mdname(mddev));
4981 			fput(mddev->bitmap_file);
4982 			mddev->bitmap_file = NULL;
4983 			return err;
4984 		}
4985 		mddev->bitmap_offset = 0; /* file overrides offset */
4986 	} else if (mddev->bitmap == NULL)
4987 		return -ENOENT; /* cannot remove what isn't there */
4988 	err = 0;
4989 	if (mddev->pers) {
4990 		mddev->pers->quiesce(mddev, 1);
4991 		if (fd >= 0)
4992 			err = bitmap_create(mddev);
4993 		if (fd < 0 || err) {
4994 			bitmap_destroy(mddev);
4995 			fd = -1; /* make sure to put the file */
4996 		}
4997 		mddev->pers->quiesce(mddev, 0);
4998 	}
4999 	if (fd < 0) {
5000 		if (mddev->bitmap_file) {
5001 			restore_bitmap_write_access(mddev->bitmap_file);
5002 			fput(mddev->bitmap_file);
5003 		}
5004 		mddev->bitmap_file = NULL;
5005 	}
5006 
5007 	return err;
5008 }
5009 
5010 /*
5011  * set_array_info is used two different ways
5012  * The original usage is when creating a new array.
5013  * In this usage, raid_disks is > 0 and it together with
5014  *  level, size, not_persistent,layout,chunksize determine the
5015  *  shape of the array.
5016  *  This will always create an array with a type-0.90.0 superblock.
5017  * The newer usage is when assembling an array.
5018  *  In this case raid_disks will be 0, and the major_version field is
5019  *  use to determine which style super-blocks are to be found on the devices.
5020  *  The minor and patch _version numbers are also kept incase the
5021  *  super_block handler wishes to interpret them.
5022  */
5023 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5024 {
5025 
5026 	if (info->raid_disks == 0) {
5027 		/* just setting version number for superblock loading */
5028 		if (info->major_version < 0 ||
5029 		    info->major_version >= ARRAY_SIZE(super_types) ||
5030 		    super_types[info->major_version].name == NULL) {
5031 			/* maybe try to auto-load a module? */
5032 			printk(KERN_INFO
5033 				"md: superblock version %d not known\n",
5034 				info->major_version);
5035 			return -EINVAL;
5036 		}
5037 		mddev->major_version = info->major_version;
5038 		mddev->minor_version = info->minor_version;
5039 		mddev->patch_version = info->patch_version;
5040 		mddev->persistent = !info->not_persistent;
5041 		return 0;
5042 	}
5043 	mddev->major_version = MD_MAJOR_VERSION;
5044 	mddev->minor_version = MD_MINOR_VERSION;
5045 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5046 	mddev->ctime         = get_seconds();
5047 
5048 	mddev->level         = info->level;
5049 	mddev->clevel[0]     = 0;
5050 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5051 	mddev->raid_disks    = info->raid_disks;
5052 	/* don't set md_minor, it is determined by which /dev/md* was
5053 	 * openned
5054 	 */
5055 	if (info->state & (1<<MD_SB_CLEAN))
5056 		mddev->recovery_cp = MaxSector;
5057 	else
5058 		mddev->recovery_cp = 0;
5059 	mddev->persistent    = ! info->not_persistent;
5060 	mddev->external	     = 0;
5061 
5062 	mddev->layout        = info->layout;
5063 	mddev->chunk_sectors = info->chunk_size >> 9;
5064 
5065 	mddev->max_disks     = MD_SB_DISKS;
5066 
5067 	if (mddev->persistent)
5068 		mddev->flags         = 0;
5069 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5070 
5071 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
5072 	mddev->bitmap_offset = 0;
5073 
5074 	mddev->reshape_position = MaxSector;
5075 
5076 	/*
5077 	 * Generate a 128 bit UUID
5078 	 */
5079 	get_random_bytes(mddev->uuid, 16);
5080 
5081 	mddev->new_level = mddev->level;
5082 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5083 	mddev->new_layout = mddev->layout;
5084 	mddev->delta_disks = 0;
5085 
5086 	return 0;
5087 }
5088 
5089 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5090 {
5091 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5092 
5093 	if (mddev->external_size)
5094 		return;
5095 
5096 	mddev->array_sectors = array_sectors;
5097 }
5098 EXPORT_SYMBOL(md_set_array_sectors);
5099 
5100 static int update_size(mddev_t *mddev, sector_t num_sectors)
5101 {
5102 	mdk_rdev_t *rdev;
5103 	int rv;
5104 	int fit = (num_sectors == 0);
5105 
5106 	if (mddev->pers->resize == NULL)
5107 		return -EINVAL;
5108 	/* The "num_sectors" is the number of sectors of each device that
5109 	 * is used.  This can only make sense for arrays with redundancy.
5110 	 * linear and raid0 always use whatever space is available. We can only
5111 	 * consider changing this number if no resync or reconstruction is
5112 	 * happening, and if the new size is acceptable. It must fit before the
5113 	 * sb_start or, if that is <data_offset, it must fit before the size
5114 	 * of each device.  If num_sectors is zero, we find the largest size
5115 	 * that fits.
5116 
5117 	 */
5118 	if (mddev->sync_thread)
5119 		return -EBUSY;
5120 	if (mddev->bitmap)
5121 		/* Sorry, cannot grow a bitmap yet, just remove it,
5122 		 * grow, and re-add.
5123 		 */
5124 		return -EBUSY;
5125 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5126 		sector_t avail = rdev->sectors;
5127 
5128 		if (fit && (num_sectors == 0 || num_sectors > avail))
5129 			num_sectors = avail;
5130 		if (avail < num_sectors)
5131 			return -ENOSPC;
5132 	}
5133 	rv = mddev->pers->resize(mddev, num_sectors);
5134 	if (!rv)
5135 		revalidate_disk(mddev->gendisk);
5136 	return rv;
5137 }
5138 
5139 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5140 {
5141 	int rv;
5142 	/* change the number of raid disks */
5143 	if (mddev->pers->check_reshape == NULL)
5144 		return -EINVAL;
5145 	if (raid_disks <= 0 ||
5146 	    raid_disks >= mddev->max_disks)
5147 		return -EINVAL;
5148 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5149 		return -EBUSY;
5150 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5151 
5152 	rv = mddev->pers->check_reshape(mddev);
5153 	return rv;
5154 }
5155 
5156 
5157 /*
5158  * update_array_info is used to change the configuration of an
5159  * on-line array.
5160  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5161  * fields in the info are checked against the array.
5162  * Any differences that cannot be handled will cause an error.
5163  * Normally, only one change can be managed at a time.
5164  */
5165 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5166 {
5167 	int rv = 0;
5168 	int cnt = 0;
5169 	int state = 0;
5170 
5171 	/* calculate expected state,ignoring low bits */
5172 	if (mddev->bitmap && mddev->bitmap_offset)
5173 		state |= (1 << MD_SB_BITMAP_PRESENT);
5174 
5175 	if (mddev->major_version != info->major_version ||
5176 	    mddev->minor_version != info->minor_version ||
5177 /*	    mddev->patch_version != info->patch_version || */
5178 	    mddev->ctime         != info->ctime         ||
5179 	    mddev->level         != info->level         ||
5180 /*	    mddev->layout        != info->layout        || */
5181 	    !mddev->persistent	 != info->not_persistent||
5182 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5183 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5184 	    ((state^info->state) & 0xfffffe00)
5185 		)
5186 		return -EINVAL;
5187 	/* Check there is only one change */
5188 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5189 		cnt++;
5190 	if (mddev->raid_disks != info->raid_disks)
5191 		cnt++;
5192 	if (mddev->layout != info->layout)
5193 		cnt++;
5194 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5195 		cnt++;
5196 	if (cnt == 0)
5197 		return 0;
5198 	if (cnt > 1)
5199 		return -EINVAL;
5200 
5201 	if (mddev->layout != info->layout) {
5202 		/* Change layout
5203 		 * we don't need to do anything at the md level, the
5204 		 * personality will take care of it all.
5205 		 */
5206 		if (mddev->pers->check_reshape == NULL)
5207 			return -EINVAL;
5208 		else {
5209 			mddev->new_layout = info->layout;
5210 			rv = mddev->pers->check_reshape(mddev);
5211 			if (rv)
5212 				mddev->new_layout = mddev->layout;
5213 			return rv;
5214 		}
5215 	}
5216 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5217 		rv = update_size(mddev, (sector_t)info->size * 2);
5218 
5219 	if (mddev->raid_disks    != info->raid_disks)
5220 		rv = update_raid_disks(mddev, info->raid_disks);
5221 
5222 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5223 		if (mddev->pers->quiesce == NULL)
5224 			return -EINVAL;
5225 		if (mddev->recovery || mddev->sync_thread)
5226 			return -EBUSY;
5227 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5228 			/* add the bitmap */
5229 			if (mddev->bitmap)
5230 				return -EEXIST;
5231 			if (mddev->default_bitmap_offset == 0)
5232 				return -EINVAL;
5233 			mddev->bitmap_offset = mddev->default_bitmap_offset;
5234 			mddev->pers->quiesce(mddev, 1);
5235 			rv = bitmap_create(mddev);
5236 			if (rv)
5237 				bitmap_destroy(mddev);
5238 			mddev->pers->quiesce(mddev, 0);
5239 		} else {
5240 			/* remove the bitmap */
5241 			if (!mddev->bitmap)
5242 				return -ENOENT;
5243 			if (mddev->bitmap->file)
5244 				return -EINVAL;
5245 			mddev->pers->quiesce(mddev, 1);
5246 			bitmap_destroy(mddev);
5247 			mddev->pers->quiesce(mddev, 0);
5248 			mddev->bitmap_offset = 0;
5249 		}
5250 	}
5251 	md_update_sb(mddev, 1);
5252 	return rv;
5253 }
5254 
5255 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5256 {
5257 	mdk_rdev_t *rdev;
5258 
5259 	if (mddev->pers == NULL)
5260 		return -ENODEV;
5261 
5262 	rdev = find_rdev(mddev, dev);
5263 	if (!rdev)
5264 		return -ENODEV;
5265 
5266 	md_error(mddev, rdev);
5267 	return 0;
5268 }
5269 
5270 /*
5271  * We have a problem here : there is no easy way to give a CHS
5272  * virtual geometry. We currently pretend that we have a 2 heads
5273  * 4 sectors (with a BIG number of cylinders...). This drives
5274  * dosfs just mad... ;-)
5275  */
5276 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5277 {
5278 	mddev_t *mddev = bdev->bd_disk->private_data;
5279 
5280 	geo->heads = 2;
5281 	geo->sectors = 4;
5282 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
5283 	return 0;
5284 }
5285 
5286 static int md_ioctl(struct block_device *bdev, fmode_t mode,
5287 			unsigned int cmd, unsigned long arg)
5288 {
5289 	int err = 0;
5290 	void __user *argp = (void __user *)arg;
5291 	mddev_t *mddev = NULL;
5292 
5293 	if (!capable(CAP_SYS_ADMIN))
5294 		return -EACCES;
5295 
5296 	/*
5297 	 * Commands dealing with the RAID driver but not any
5298 	 * particular array:
5299 	 */
5300 	switch (cmd)
5301 	{
5302 		case RAID_VERSION:
5303 			err = get_version(argp);
5304 			goto done;
5305 
5306 		case PRINT_RAID_DEBUG:
5307 			err = 0;
5308 			md_print_devices();
5309 			goto done;
5310 
5311 #ifndef MODULE
5312 		case RAID_AUTORUN:
5313 			err = 0;
5314 			autostart_arrays(arg);
5315 			goto done;
5316 #endif
5317 		default:;
5318 	}
5319 
5320 	/*
5321 	 * Commands creating/starting a new array:
5322 	 */
5323 
5324 	mddev = bdev->bd_disk->private_data;
5325 
5326 	if (!mddev) {
5327 		BUG();
5328 		goto abort;
5329 	}
5330 
5331 	err = mddev_lock(mddev);
5332 	if (err) {
5333 		printk(KERN_INFO
5334 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5335 			err, cmd);
5336 		goto abort;
5337 	}
5338 
5339 	switch (cmd)
5340 	{
5341 		case SET_ARRAY_INFO:
5342 			{
5343 				mdu_array_info_t info;
5344 				if (!arg)
5345 					memset(&info, 0, sizeof(info));
5346 				else if (copy_from_user(&info, argp, sizeof(info))) {
5347 					err = -EFAULT;
5348 					goto abort_unlock;
5349 				}
5350 				if (mddev->pers) {
5351 					err = update_array_info(mddev, &info);
5352 					if (err) {
5353 						printk(KERN_WARNING "md: couldn't update"
5354 						       " array info. %d\n", err);
5355 						goto abort_unlock;
5356 					}
5357 					goto done_unlock;
5358 				}
5359 				if (!list_empty(&mddev->disks)) {
5360 					printk(KERN_WARNING
5361 					       "md: array %s already has disks!\n",
5362 					       mdname(mddev));
5363 					err = -EBUSY;
5364 					goto abort_unlock;
5365 				}
5366 				if (mddev->raid_disks) {
5367 					printk(KERN_WARNING
5368 					       "md: array %s already initialised!\n",
5369 					       mdname(mddev));
5370 					err = -EBUSY;
5371 					goto abort_unlock;
5372 				}
5373 				err = set_array_info(mddev, &info);
5374 				if (err) {
5375 					printk(KERN_WARNING "md: couldn't set"
5376 					       " array info. %d\n", err);
5377 					goto abort_unlock;
5378 				}
5379 			}
5380 			goto done_unlock;
5381 
5382 		default:;
5383 	}
5384 
5385 	/*
5386 	 * Commands querying/configuring an existing array:
5387 	 */
5388 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5389 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5390 	if ((!mddev->raid_disks && !mddev->external)
5391 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5392 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5393 	    && cmd != GET_BITMAP_FILE) {
5394 		err = -ENODEV;
5395 		goto abort_unlock;
5396 	}
5397 
5398 	/*
5399 	 * Commands even a read-only array can execute:
5400 	 */
5401 	switch (cmd)
5402 	{
5403 		case GET_ARRAY_INFO:
5404 			err = get_array_info(mddev, argp);
5405 			goto done_unlock;
5406 
5407 		case GET_BITMAP_FILE:
5408 			err = get_bitmap_file(mddev, argp);
5409 			goto done_unlock;
5410 
5411 		case GET_DISK_INFO:
5412 			err = get_disk_info(mddev, argp);
5413 			goto done_unlock;
5414 
5415 		case RESTART_ARRAY_RW:
5416 			err = restart_array(mddev);
5417 			goto done_unlock;
5418 
5419 		case STOP_ARRAY:
5420 			err = do_md_stop(mddev, 0, 1);
5421 			goto done_unlock;
5422 
5423 		case STOP_ARRAY_RO:
5424 			err = do_md_stop(mddev, 1, 1);
5425 			goto done_unlock;
5426 
5427 	}
5428 
5429 	/*
5430 	 * The remaining ioctls are changing the state of the
5431 	 * superblock, so we do not allow them on read-only arrays.
5432 	 * However non-MD ioctls (e.g. get-size) will still come through
5433 	 * here and hit the 'default' below, so only disallow
5434 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5435 	 */
5436 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5437 		if (mddev->ro == 2) {
5438 			mddev->ro = 0;
5439 			sysfs_notify_dirent(mddev->sysfs_state);
5440 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5441 			md_wakeup_thread(mddev->thread);
5442 		} else {
5443 			err = -EROFS;
5444 			goto abort_unlock;
5445 		}
5446 	}
5447 
5448 	switch (cmd)
5449 	{
5450 		case ADD_NEW_DISK:
5451 		{
5452 			mdu_disk_info_t info;
5453 			if (copy_from_user(&info, argp, sizeof(info)))
5454 				err = -EFAULT;
5455 			else
5456 				err = add_new_disk(mddev, &info);
5457 			goto done_unlock;
5458 		}
5459 
5460 		case HOT_REMOVE_DISK:
5461 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5462 			goto done_unlock;
5463 
5464 		case HOT_ADD_DISK:
5465 			err = hot_add_disk(mddev, new_decode_dev(arg));
5466 			goto done_unlock;
5467 
5468 		case SET_DISK_FAULTY:
5469 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5470 			goto done_unlock;
5471 
5472 		case RUN_ARRAY:
5473 			err = do_md_run(mddev);
5474 			goto done_unlock;
5475 
5476 		case SET_BITMAP_FILE:
5477 			err = set_bitmap_file(mddev, (int)arg);
5478 			goto done_unlock;
5479 
5480 		default:
5481 			err = -EINVAL;
5482 			goto abort_unlock;
5483 	}
5484 
5485 done_unlock:
5486 abort_unlock:
5487 	if (mddev->hold_active == UNTIL_IOCTL &&
5488 	    err != -EINVAL)
5489 		mddev->hold_active = 0;
5490 	mddev_unlock(mddev);
5491 
5492 	return err;
5493 done:
5494 	if (err)
5495 		MD_BUG();
5496 abort:
5497 	return err;
5498 }
5499 
5500 static int md_open(struct block_device *bdev, fmode_t mode)
5501 {
5502 	/*
5503 	 * Succeed if we can lock the mddev, which confirms that
5504 	 * it isn't being stopped right now.
5505 	 */
5506 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5507 	int err;
5508 
5509 	if (mddev->gendisk != bdev->bd_disk) {
5510 		/* we are racing with mddev_put which is discarding this
5511 		 * bd_disk.
5512 		 */
5513 		mddev_put(mddev);
5514 		/* Wait until bdev->bd_disk is definitely gone */
5515 		flush_scheduled_work();
5516 		/* Then retry the open from the top */
5517 		return -ERESTARTSYS;
5518 	}
5519 	BUG_ON(mddev != bdev->bd_disk->private_data);
5520 
5521 	if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
5522 		goto out;
5523 
5524 	err = 0;
5525 	atomic_inc(&mddev->openers);
5526 	mddev_unlock(mddev);
5527 
5528 	check_disk_change(bdev);
5529  out:
5530 	return err;
5531 }
5532 
5533 static int md_release(struct gendisk *disk, fmode_t mode)
5534 {
5535  	mddev_t *mddev = disk->private_data;
5536 
5537 	BUG_ON(!mddev);
5538 	atomic_dec(&mddev->openers);
5539 	mddev_put(mddev);
5540 
5541 	return 0;
5542 }
5543 
5544 static int md_media_changed(struct gendisk *disk)
5545 {
5546 	mddev_t *mddev = disk->private_data;
5547 
5548 	return mddev->changed;
5549 }
5550 
5551 static int md_revalidate(struct gendisk *disk)
5552 {
5553 	mddev_t *mddev = disk->private_data;
5554 
5555 	mddev->changed = 0;
5556 	return 0;
5557 }
5558 static struct block_device_operations md_fops =
5559 {
5560 	.owner		= THIS_MODULE,
5561 	.open		= md_open,
5562 	.release	= md_release,
5563 	.ioctl		= md_ioctl,
5564 	.getgeo		= md_getgeo,
5565 	.media_changed	= md_media_changed,
5566 	.revalidate_disk= md_revalidate,
5567 };
5568 
5569 static int md_thread(void * arg)
5570 {
5571 	mdk_thread_t *thread = arg;
5572 
5573 	/*
5574 	 * md_thread is a 'system-thread', it's priority should be very
5575 	 * high. We avoid resource deadlocks individually in each
5576 	 * raid personality. (RAID5 does preallocation) We also use RR and
5577 	 * the very same RT priority as kswapd, thus we will never get
5578 	 * into a priority inversion deadlock.
5579 	 *
5580 	 * we definitely have to have equal or higher priority than
5581 	 * bdflush, otherwise bdflush will deadlock if there are too
5582 	 * many dirty RAID5 blocks.
5583 	 */
5584 
5585 	allow_signal(SIGKILL);
5586 	while (!kthread_should_stop()) {
5587 
5588 		/* We need to wait INTERRUPTIBLE so that
5589 		 * we don't add to the load-average.
5590 		 * That means we need to be sure no signals are
5591 		 * pending
5592 		 */
5593 		if (signal_pending(current))
5594 			flush_signals(current);
5595 
5596 		wait_event_interruptible_timeout
5597 			(thread->wqueue,
5598 			 test_bit(THREAD_WAKEUP, &thread->flags)
5599 			 || kthread_should_stop(),
5600 			 thread->timeout);
5601 
5602 		clear_bit(THREAD_WAKEUP, &thread->flags);
5603 
5604 		thread->run(thread->mddev);
5605 	}
5606 
5607 	return 0;
5608 }
5609 
5610 void md_wakeup_thread(mdk_thread_t *thread)
5611 {
5612 	if (thread) {
5613 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
5614 		set_bit(THREAD_WAKEUP, &thread->flags);
5615 		wake_up(&thread->wqueue);
5616 	}
5617 }
5618 
5619 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
5620 				 const char *name)
5621 {
5622 	mdk_thread_t *thread;
5623 
5624 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
5625 	if (!thread)
5626 		return NULL;
5627 
5628 	init_waitqueue_head(&thread->wqueue);
5629 
5630 	thread->run = run;
5631 	thread->mddev = mddev;
5632 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
5633 	thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
5634 	if (IS_ERR(thread->tsk)) {
5635 		kfree(thread);
5636 		return NULL;
5637 	}
5638 	return thread;
5639 }
5640 
5641 void md_unregister_thread(mdk_thread_t *thread)
5642 {
5643 	if (!thread)
5644 		return;
5645 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
5646 
5647 	kthread_stop(thread->tsk);
5648 	kfree(thread);
5649 }
5650 
5651 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
5652 {
5653 	if (!mddev) {
5654 		MD_BUG();
5655 		return;
5656 	}
5657 
5658 	if (!rdev || test_bit(Faulty, &rdev->flags))
5659 		return;
5660 
5661 	if (mddev->external)
5662 		set_bit(Blocked, &rdev->flags);
5663 /*
5664 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
5665 		mdname(mddev),
5666 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
5667 		__builtin_return_address(0),__builtin_return_address(1),
5668 		__builtin_return_address(2),__builtin_return_address(3));
5669 */
5670 	if (!mddev->pers)
5671 		return;
5672 	if (!mddev->pers->error_handler)
5673 		return;
5674 	mddev->pers->error_handler(mddev,rdev);
5675 	if (mddev->degraded)
5676 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5677 	set_bit(StateChanged, &rdev->flags);
5678 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5679 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5680 	md_wakeup_thread(mddev->thread);
5681 	md_new_event_inintr(mddev);
5682 }
5683 
5684 /* seq_file implementation /proc/mdstat */
5685 
5686 static void status_unused(struct seq_file *seq)
5687 {
5688 	int i = 0;
5689 	mdk_rdev_t *rdev;
5690 
5691 	seq_printf(seq, "unused devices: ");
5692 
5693 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
5694 		char b[BDEVNAME_SIZE];
5695 		i++;
5696 		seq_printf(seq, "%s ",
5697 			      bdevname(rdev->bdev,b));
5698 	}
5699 	if (!i)
5700 		seq_printf(seq, "<none>");
5701 
5702 	seq_printf(seq, "\n");
5703 }
5704 
5705 
5706 static void status_resync(struct seq_file *seq, mddev_t * mddev)
5707 {
5708 	sector_t max_sectors, resync, res;
5709 	unsigned long dt, db;
5710 	sector_t rt;
5711 	int scale;
5712 	unsigned int per_milli;
5713 
5714 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
5715 
5716 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
5717 		max_sectors = mddev->resync_max_sectors;
5718 	else
5719 		max_sectors = mddev->dev_sectors;
5720 
5721 	/*
5722 	 * Should not happen.
5723 	 */
5724 	if (!max_sectors) {
5725 		MD_BUG();
5726 		return;
5727 	}
5728 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
5729 	 * in a sector_t, and (max_sectors>>scale) will fit in a
5730 	 * u32, as those are the requirements for sector_div.
5731 	 * Thus 'scale' must be at least 10
5732 	 */
5733 	scale = 10;
5734 	if (sizeof(sector_t) > sizeof(unsigned long)) {
5735 		while ( max_sectors/2 > (1ULL<<(scale+32)))
5736 			scale++;
5737 	}
5738 	res = (resync>>scale)*1000;
5739 	sector_div(res, (u32)((max_sectors>>scale)+1));
5740 
5741 	per_milli = res;
5742 	{
5743 		int i, x = per_milli/50, y = 20-x;
5744 		seq_printf(seq, "[");
5745 		for (i = 0; i < x; i++)
5746 			seq_printf(seq, "=");
5747 		seq_printf(seq, ">");
5748 		for (i = 0; i < y; i++)
5749 			seq_printf(seq, ".");
5750 		seq_printf(seq, "] ");
5751 	}
5752 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
5753 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
5754 		    "reshape" :
5755 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
5756 		     "check" :
5757 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
5758 		      "resync" : "recovery"))),
5759 		   per_milli/10, per_milli % 10,
5760 		   (unsigned long long) resync/2,
5761 		   (unsigned long long) max_sectors/2);
5762 
5763 	/*
5764 	 * dt: time from mark until now
5765 	 * db: blocks written from mark until now
5766 	 * rt: remaining time
5767 	 *
5768 	 * rt is a sector_t, so could be 32bit or 64bit.
5769 	 * So we divide before multiply in case it is 32bit and close
5770 	 * to the limit.
5771 	 * We scale the divisor (db) by 32 to avoid loosing precision
5772 	 * near the end of resync when the number of remaining sectors
5773 	 * is close to 'db'.
5774 	 * We then divide rt by 32 after multiplying by db to compensate.
5775 	 * The '+1' avoids division by zero if db is very small.
5776 	 */
5777 	dt = ((jiffies - mddev->resync_mark) / HZ);
5778 	if (!dt) dt++;
5779 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
5780 		- mddev->resync_mark_cnt;
5781 
5782 	rt = max_sectors - resync;    /* number of remaining sectors */
5783 	sector_div(rt, db/32+1);
5784 	rt *= dt;
5785 	rt >>= 5;
5786 
5787 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
5788 		   ((unsigned long)rt % 60)/6);
5789 
5790 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
5791 }
5792 
5793 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
5794 {
5795 	struct list_head *tmp;
5796 	loff_t l = *pos;
5797 	mddev_t *mddev;
5798 
5799 	if (l >= 0x10000)
5800 		return NULL;
5801 	if (!l--)
5802 		/* header */
5803 		return (void*)1;
5804 
5805 	spin_lock(&all_mddevs_lock);
5806 	list_for_each(tmp,&all_mddevs)
5807 		if (!l--) {
5808 			mddev = list_entry(tmp, mddev_t, all_mddevs);
5809 			mddev_get(mddev);
5810 			spin_unlock(&all_mddevs_lock);
5811 			return mddev;
5812 		}
5813 	spin_unlock(&all_mddevs_lock);
5814 	if (!l--)
5815 		return (void*)2;/* tail */
5816 	return NULL;
5817 }
5818 
5819 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
5820 {
5821 	struct list_head *tmp;
5822 	mddev_t *next_mddev, *mddev = v;
5823 
5824 	++*pos;
5825 	if (v == (void*)2)
5826 		return NULL;
5827 
5828 	spin_lock(&all_mddevs_lock);
5829 	if (v == (void*)1)
5830 		tmp = all_mddevs.next;
5831 	else
5832 		tmp = mddev->all_mddevs.next;
5833 	if (tmp != &all_mddevs)
5834 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
5835 	else {
5836 		next_mddev = (void*)2;
5837 		*pos = 0x10000;
5838 	}
5839 	spin_unlock(&all_mddevs_lock);
5840 
5841 	if (v != (void*)1)
5842 		mddev_put(mddev);
5843 	return next_mddev;
5844 
5845 }
5846 
5847 static void md_seq_stop(struct seq_file *seq, void *v)
5848 {
5849 	mddev_t *mddev = v;
5850 
5851 	if (mddev && v != (void*)1 && v != (void*)2)
5852 		mddev_put(mddev);
5853 }
5854 
5855 struct mdstat_info {
5856 	int event;
5857 };
5858 
5859 static int md_seq_show(struct seq_file *seq, void *v)
5860 {
5861 	mddev_t *mddev = v;
5862 	sector_t sectors;
5863 	mdk_rdev_t *rdev;
5864 	struct mdstat_info *mi = seq->private;
5865 	struct bitmap *bitmap;
5866 
5867 	if (v == (void*)1) {
5868 		struct mdk_personality *pers;
5869 		seq_printf(seq, "Personalities : ");
5870 		spin_lock(&pers_lock);
5871 		list_for_each_entry(pers, &pers_list, list)
5872 			seq_printf(seq, "[%s] ", pers->name);
5873 
5874 		spin_unlock(&pers_lock);
5875 		seq_printf(seq, "\n");
5876 		mi->event = atomic_read(&md_event_count);
5877 		return 0;
5878 	}
5879 	if (v == (void*)2) {
5880 		status_unused(seq);
5881 		return 0;
5882 	}
5883 
5884 	if (mddev_lock(mddev) < 0)
5885 		return -EINTR;
5886 
5887 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
5888 		seq_printf(seq, "%s : %sactive", mdname(mddev),
5889 						mddev->pers ? "" : "in");
5890 		if (mddev->pers) {
5891 			if (mddev->ro==1)
5892 				seq_printf(seq, " (read-only)");
5893 			if (mddev->ro==2)
5894 				seq_printf(seq, " (auto-read-only)");
5895 			seq_printf(seq, " %s", mddev->pers->name);
5896 		}
5897 
5898 		sectors = 0;
5899 		list_for_each_entry(rdev, &mddev->disks, same_set) {
5900 			char b[BDEVNAME_SIZE];
5901 			seq_printf(seq, " %s[%d]",
5902 				bdevname(rdev->bdev,b), rdev->desc_nr);
5903 			if (test_bit(WriteMostly, &rdev->flags))
5904 				seq_printf(seq, "(W)");
5905 			if (test_bit(Faulty, &rdev->flags)) {
5906 				seq_printf(seq, "(F)");
5907 				continue;
5908 			} else if (rdev->raid_disk < 0)
5909 				seq_printf(seq, "(S)"); /* spare */
5910 			sectors += rdev->sectors;
5911 		}
5912 
5913 		if (!list_empty(&mddev->disks)) {
5914 			if (mddev->pers)
5915 				seq_printf(seq, "\n      %llu blocks",
5916 					   (unsigned long long)
5917 					   mddev->array_sectors / 2);
5918 			else
5919 				seq_printf(seq, "\n      %llu blocks",
5920 					   (unsigned long long)sectors / 2);
5921 		}
5922 		if (mddev->persistent) {
5923 			if (mddev->major_version != 0 ||
5924 			    mddev->minor_version != 90) {
5925 				seq_printf(seq," super %d.%d",
5926 					   mddev->major_version,
5927 					   mddev->minor_version);
5928 			}
5929 		} else if (mddev->external)
5930 			seq_printf(seq, " super external:%s",
5931 				   mddev->metadata_type);
5932 		else
5933 			seq_printf(seq, " super non-persistent");
5934 
5935 		if (mddev->pers) {
5936 			mddev->pers->status(seq, mddev);
5937 	 		seq_printf(seq, "\n      ");
5938 			if (mddev->pers->sync_request) {
5939 				if (mddev->curr_resync > 2) {
5940 					status_resync(seq, mddev);
5941 					seq_printf(seq, "\n      ");
5942 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
5943 					seq_printf(seq, "\tresync=DELAYED\n      ");
5944 				else if (mddev->recovery_cp < MaxSector)
5945 					seq_printf(seq, "\tresync=PENDING\n      ");
5946 			}
5947 		} else
5948 			seq_printf(seq, "\n       ");
5949 
5950 		if ((bitmap = mddev->bitmap)) {
5951 			unsigned long chunk_kb;
5952 			unsigned long flags;
5953 			spin_lock_irqsave(&bitmap->lock, flags);
5954 			chunk_kb = bitmap->chunksize >> 10;
5955 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
5956 				"%lu%s chunk",
5957 				bitmap->pages - bitmap->missing_pages,
5958 				bitmap->pages,
5959 				(bitmap->pages - bitmap->missing_pages)
5960 					<< (PAGE_SHIFT - 10),
5961 				chunk_kb ? chunk_kb : bitmap->chunksize,
5962 				chunk_kb ? "KB" : "B");
5963 			if (bitmap->file) {
5964 				seq_printf(seq, ", file: ");
5965 				seq_path(seq, &bitmap->file->f_path, " \t\n");
5966 			}
5967 
5968 			seq_printf(seq, "\n");
5969 			spin_unlock_irqrestore(&bitmap->lock, flags);
5970 		}
5971 
5972 		seq_printf(seq, "\n");
5973 	}
5974 	mddev_unlock(mddev);
5975 
5976 	return 0;
5977 }
5978 
5979 static const struct seq_operations md_seq_ops = {
5980 	.start  = md_seq_start,
5981 	.next   = md_seq_next,
5982 	.stop   = md_seq_stop,
5983 	.show   = md_seq_show,
5984 };
5985 
5986 static int md_seq_open(struct inode *inode, struct file *file)
5987 {
5988 	int error;
5989 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
5990 	if (mi == NULL)
5991 		return -ENOMEM;
5992 
5993 	error = seq_open(file, &md_seq_ops);
5994 	if (error)
5995 		kfree(mi);
5996 	else {
5997 		struct seq_file *p = file->private_data;
5998 		p->private = mi;
5999 		mi->event = atomic_read(&md_event_count);
6000 	}
6001 	return error;
6002 }
6003 
6004 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6005 {
6006 	struct seq_file *m = filp->private_data;
6007 	struct mdstat_info *mi = m->private;
6008 	int mask;
6009 
6010 	poll_wait(filp, &md_event_waiters, wait);
6011 
6012 	/* always allow read */
6013 	mask = POLLIN | POLLRDNORM;
6014 
6015 	if (mi->event != atomic_read(&md_event_count))
6016 		mask |= POLLERR | POLLPRI;
6017 	return mask;
6018 }
6019 
6020 static const struct file_operations md_seq_fops = {
6021 	.owner		= THIS_MODULE,
6022 	.open           = md_seq_open,
6023 	.read           = seq_read,
6024 	.llseek         = seq_lseek,
6025 	.release	= seq_release_private,
6026 	.poll		= mdstat_poll,
6027 };
6028 
6029 int register_md_personality(struct mdk_personality *p)
6030 {
6031 	spin_lock(&pers_lock);
6032 	list_add_tail(&p->list, &pers_list);
6033 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6034 	spin_unlock(&pers_lock);
6035 	return 0;
6036 }
6037 
6038 int unregister_md_personality(struct mdk_personality *p)
6039 {
6040 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6041 	spin_lock(&pers_lock);
6042 	list_del_init(&p->list);
6043 	spin_unlock(&pers_lock);
6044 	return 0;
6045 }
6046 
6047 static int is_mddev_idle(mddev_t *mddev, int init)
6048 {
6049 	mdk_rdev_t * rdev;
6050 	int idle;
6051 	int curr_events;
6052 
6053 	idle = 1;
6054 	rcu_read_lock();
6055 	rdev_for_each_rcu(rdev, mddev) {
6056 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6057 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6058 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6059 			      atomic_read(&disk->sync_io);
6060 		/* sync IO will cause sync_io to increase before the disk_stats
6061 		 * as sync_io is counted when a request starts, and
6062 		 * disk_stats is counted when it completes.
6063 		 * So resync activity will cause curr_events to be smaller than
6064 		 * when there was no such activity.
6065 		 * non-sync IO will cause disk_stat to increase without
6066 		 * increasing sync_io so curr_events will (eventually)
6067 		 * be larger than it was before.  Once it becomes
6068 		 * substantially larger, the test below will cause
6069 		 * the array to appear non-idle, and resync will slow
6070 		 * down.
6071 		 * If there is a lot of outstanding resync activity when
6072 		 * we set last_event to curr_events, then all that activity
6073 		 * completing might cause the array to appear non-idle
6074 		 * and resync will be slowed down even though there might
6075 		 * not have been non-resync activity.  This will only
6076 		 * happen once though.  'last_events' will soon reflect
6077 		 * the state where there is little or no outstanding
6078 		 * resync requests, and further resync activity will
6079 		 * always make curr_events less than last_events.
6080 		 *
6081 		 */
6082 		if (init || curr_events - rdev->last_events > 64) {
6083 			rdev->last_events = curr_events;
6084 			idle = 0;
6085 		}
6086 	}
6087 	rcu_read_unlock();
6088 	return idle;
6089 }
6090 
6091 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6092 {
6093 	/* another "blocks" (512byte) blocks have been synced */
6094 	atomic_sub(blocks, &mddev->recovery_active);
6095 	wake_up(&mddev->recovery_wait);
6096 	if (!ok) {
6097 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6098 		md_wakeup_thread(mddev->thread);
6099 		// stop recovery, signal do_sync ....
6100 	}
6101 }
6102 
6103 
6104 /* md_write_start(mddev, bi)
6105  * If we need to update some array metadata (e.g. 'active' flag
6106  * in superblock) before writing, schedule a superblock update
6107  * and wait for it to complete.
6108  */
6109 void md_write_start(mddev_t *mddev, struct bio *bi)
6110 {
6111 	int did_change = 0;
6112 	if (bio_data_dir(bi) != WRITE)
6113 		return;
6114 
6115 	BUG_ON(mddev->ro == 1);
6116 	if (mddev->ro == 2) {
6117 		/* need to switch to read/write */
6118 		mddev->ro = 0;
6119 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6120 		md_wakeup_thread(mddev->thread);
6121 		md_wakeup_thread(mddev->sync_thread);
6122 		did_change = 1;
6123 	}
6124 	atomic_inc(&mddev->writes_pending);
6125 	if (mddev->safemode == 1)
6126 		mddev->safemode = 0;
6127 	if (mddev->in_sync) {
6128 		spin_lock_irq(&mddev->write_lock);
6129 		if (mddev->in_sync) {
6130 			mddev->in_sync = 0;
6131 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6132 			md_wakeup_thread(mddev->thread);
6133 			did_change = 1;
6134 		}
6135 		spin_unlock_irq(&mddev->write_lock);
6136 	}
6137 	if (did_change)
6138 		sysfs_notify_dirent(mddev->sysfs_state);
6139 	wait_event(mddev->sb_wait,
6140 		   !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
6141 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6142 }
6143 
6144 void md_write_end(mddev_t *mddev)
6145 {
6146 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6147 		if (mddev->safemode == 2)
6148 			md_wakeup_thread(mddev->thread);
6149 		else if (mddev->safemode_delay)
6150 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6151 	}
6152 }
6153 
6154 /* md_allow_write(mddev)
6155  * Calling this ensures that the array is marked 'active' so that writes
6156  * may proceed without blocking.  It is important to call this before
6157  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6158  * Must be called with mddev_lock held.
6159  *
6160  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6161  * is dropped, so return -EAGAIN after notifying userspace.
6162  */
6163 int md_allow_write(mddev_t *mddev)
6164 {
6165 	if (!mddev->pers)
6166 		return 0;
6167 	if (mddev->ro)
6168 		return 0;
6169 	if (!mddev->pers->sync_request)
6170 		return 0;
6171 
6172 	spin_lock_irq(&mddev->write_lock);
6173 	if (mddev->in_sync) {
6174 		mddev->in_sync = 0;
6175 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6176 		if (mddev->safemode_delay &&
6177 		    mddev->safemode == 0)
6178 			mddev->safemode = 1;
6179 		spin_unlock_irq(&mddev->write_lock);
6180 		md_update_sb(mddev, 0);
6181 		sysfs_notify_dirent(mddev->sysfs_state);
6182 	} else
6183 		spin_unlock_irq(&mddev->write_lock);
6184 
6185 	if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
6186 		return -EAGAIN;
6187 	else
6188 		return 0;
6189 }
6190 EXPORT_SYMBOL_GPL(md_allow_write);
6191 
6192 #define SYNC_MARKS	10
6193 #define	SYNC_MARK_STEP	(3*HZ)
6194 void md_do_sync(mddev_t *mddev)
6195 {
6196 	mddev_t *mddev2;
6197 	unsigned int currspeed = 0,
6198 		 window;
6199 	sector_t max_sectors,j, io_sectors;
6200 	unsigned long mark[SYNC_MARKS];
6201 	sector_t mark_cnt[SYNC_MARKS];
6202 	int last_mark,m;
6203 	struct list_head *tmp;
6204 	sector_t last_check;
6205 	int skipped = 0;
6206 	mdk_rdev_t *rdev;
6207 	char *desc;
6208 
6209 	/* just incase thread restarts... */
6210 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6211 		return;
6212 	if (mddev->ro) /* never try to sync a read-only array */
6213 		return;
6214 
6215 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6216 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6217 			desc = "data-check";
6218 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6219 			desc = "requested-resync";
6220 		else
6221 			desc = "resync";
6222 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6223 		desc = "reshape";
6224 	else
6225 		desc = "recovery";
6226 
6227 	/* we overload curr_resync somewhat here.
6228 	 * 0 == not engaged in resync at all
6229 	 * 2 == checking that there is no conflict with another sync
6230 	 * 1 == like 2, but have yielded to allow conflicting resync to
6231 	 *		commense
6232 	 * other == active in resync - this many blocks
6233 	 *
6234 	 * Before starting a resync we must have set curr_resync to
6235 	 * 2, and then checked that every "conflicting" array has curr_resync
6236 	 * less than ours.  When we find one that is the same or higher
6237 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6238 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6239 	 * This will mean we have to start checking from the beginning again.
6240 	 *
6241 	 */
6242 
6243 	do {
6244 		mddev->curr_resync = 2;
6245 
6246 	try_again:
6247 		if (kthread_should_stop()) {
6248 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6249 			goto skip;
6250 		}
6251 		for_each_mddev(mddev2, tmp) {
6252 			if (mddev2 == mddev)
6253 				continue;
6254 			if (!mddev->parallel_resync
6255 			&&  mddev2->curr_resync
6256 			&&  match_mddev_units(mddev, mddev2)) {
6257 				DEFINE_WAIT(wq);
6258 				if (mddev < mddev2 && mddev->curr_resync == 2) {
6259 					/* arbitrarily yield */
6260 					mddev->curr_resync = 1;
6261 					wake_up(&resync_wait);
6262 				}
6263 				if (mddev > mddev2 && mddev->curr_resync == 1)
6264 					/* no need to wait here, we can wait the next
6265 					 * time 'round when curr_resync == 2
6266 					 */
6267 					continue;
6268 				/* We need to wait 'interruptible' so as not to
6269 				 * contribute to the load average, and not to
6270 				 * be caught by 'softlockup'
6271 				 */
6272 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
6273 				if (!kthread_should_stop() &&
6274 				    mddev2->curr_resync >= mddev->curr_resync) {
6275 					printk(KERN_INFO "md: delaying %s of %s"
6276 					       " until %s has finished (they"
6277 					       " share one or more physical units)\n",
6278 					       desc, mdname(mddev), mdname(mddev2));
6279 					mddev_put(mddev2);
6280 					if (signal_pending(current))
6281 						flush_signals(current);
6282 					schedule();
6283 					finish_wait(&resync_wait, &wq);
6284 					goto try_again;
6285 				}
6286 				finish_wait(&resync_wait, &wq);
6287 			}
6288 		}
6289 	} while (mddev->curr_resync < 2);
6290 
6291 	j = 0;
6292 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6293 		/* resync follows the size requested by the personality,
6294 		 * which defaults to physical size, but can be virtual size
6295 		 */
6296 		max_sectors = mddev->resync_max_sectors;
6297 		mddev->resync_mismatches = 0;
6298 		/* we don't use the checkpoint if there's a bitmap */
6299 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6300 			j = mddev->resync_min;
6301 		else if (!mddev->bitmap)
6302 			j = mddev->recovery_cp;
6303 
6304 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6305 		max_sectors = mddev->dev_sectors;
6306 	else {
6307 		/* recovery follows the physical size of devices */
6308 		max_sectors = mddev->dev_sectors;
6309 		j = MaxSector;
6310 		list_for_each_entry(rdev, &mddev->disks, same_set)
6311 			if (rdev->raid_disk >= 0 &&
6312 			    !test_bit(Faulty, &rdev->flags) &&
6313 			    !test_bit(In_sync, &rdev->flags) &&
6314 			    rdev->recovery_offset < j)
6315 				j = rdev->recovery_offset;
6316 	}
6317 
6318 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
6319 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
6320 		" %d KB/sec/disk.\n", speed_min(mddev));
6321 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6322 	       "(but not more than %d KB/sec) for %s.\n",
6323 	       speed_max(mddev), desc);
6324 
6325 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
6326 
6327 	io_sectors = 0;
6328 	for (m = 0; m < SYNC_MARKS; m++) {
6329 		mark[m] = jiffies;
6330 		mark_cnt[m] = io_sectors;
6331 	}
6332 	last_mark = 0;
6333 	mddev->resync_mark = mark[last_mark];
6334 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6335 
6336 	/*
6337 	 * Tune reconstruction:
6338 	 */
6339 	window = 32*(PAGE_SIZE/512);
6340 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6341 		window/2,(unsigned long long) max_sectors/2);
6342 
6343 	atomic_set(&mddev->recovery_active, 0);
6344 	last_check = 0;
6345 
6346 	if (j>2) {
6347 		printk(KERN_INFO
6348 		       "md: resuming %s of %s from checkpoint.\n",
6349 		       desc, mdname(mddev));
6350 		mddev->curr_resync = j;
6351 	}
6352 
6353 	while (j < max_sectors) {
6354 		sector_t sectors;
6355 
6356 		skipped = 0;
6357 
6358 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6359 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
6360 		      (mddev->curr_resync - mddev->curr_resync_completed)
6361 		      > (max_sectors >> 4)) ||
6362 		     (j - mddev->curr_resync_completed)*2
6363 		     >= mddev->resync_max - mddev->curr_resync_completed
6364 			    )) {
6365 			/* time to update curr_resync_completed */
6366 			blk_unplug(mddev->queue);
6367 			wait_event(mddev->recovery_wait,
6368 				   atomic_read(&mddev->recovery_active) == 0);
6369 			mddev->curr_resync_completed =
6370 				mddev->curr_resync;
6371 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6372 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6373 		}
6374 
6375 		while (j >= mddev->resync_max && !kthread_should_stop()) {
6376 			/* As this condition is controlled by user-space,
6377 			 * we can block indefinitely, so use '_interruptible'
6378 			 * to avoid triggering warnings.
6379 			 */
6380 			flush_signals(current); /* just in case */
6381 			wait_event_interruptible(mddev->recovery_wait,
6382 						 mddev->resync_max > j
6383 						 || kthread_should_stop());
6384 		}
6385 
6386 		if (kthread_should_stop())
6387 			goto interrupted;
6388 
6389 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6390 						  currspeed < speed_min(mddev));
6391 		if (sectors == 0) {
6392 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6393 			goto out;
6394 		}
6395 
6396 		if (!skipped) { /* actual IO requested */
6397 			io_sectors += sectors;
6398 			atomic_add(sectors, &mddev->recovery_active);
6399 		}
6400 
6401 		j += sectors;
6402 		if (j>1) mddev->curr_resync = j;
6403 		mddev->curr_mark_cnt = io_sectors;
6404 		if (last_check == 0)
6405 			/* this is the earliers that rebuilt will be
6406 			 * visible in /proc/mdstat
6407 			 */
6408 			md_new_event(mddev);
6409 
6410 		if (last_check + window > io_sectors || j == max_sectors)
6411 			continue;
6412 
6413 		last_check = io_sectors;
6414 
6415 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6416 			break;
6417 
6418 	repeat:
6419 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6420 			/* step marks */
6421 			int next = (last_mark+1) % SYNC_MARKS;
6422 
6423 			mddev->resync_mark = mark[next];
6424 			mddev->resync_mark_cnt = mark_cnt[next];
6425 			mark[next] = jiffies;
6426 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6427 			last_mark = next;
6428 		}
6429 
6430 
6431 		if (kthread_should_stop())
6432 			goto interrupted;
6433 
6434 
6435 		/*
6436 		 * this loop exits only if either when we are slower than
6437 		 * the 'hard' speed limit, or the system was IO-idle for
6438 		 * a jiffy.
6439 		 * the system might be non-idle CPU-wise, but we only care
6440 		 * about not overloading the IO subsystem. (things like an
6441 		 * e2fsck being done on the RAID array should execute fast)
6442 		 */
6443 		blk_unplug(mddev->queue);
6444 		cond_resched();
6445 
6446 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6447 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6448 
6449 		if (currspeed > speed_min(mddev)) {
6450 			if ((currspeed > speed_max(mddev)) ||
6451 					!is_mddev_idle(mddev, 0)) {
6452 				msleep(500);
6453 				goto repeat;
6454 			}
6455 		}
6456 	}
6457 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6458 	/*
6459 	 * this also signals 'finished resyncing' to md_stop
6460 	 */
6461  out:
6462 	blk_unplug(mddev->queue);
6463 
6464 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6465 
6466 	/* tell personality that we are finished */
6467 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6468 
6469 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6470 	    mddev->curr_resync > 2) {
6471 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6472 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6473 				if (mddev->curr_resync >= mddev->recovery_cp) {
6474 					printk(KERN_INFO
6475 					       "md: checkpointing %s of %s.\n",
6476 					       desc, mdname(mddev));
6477 					mddev->recovery_cp = mddev->curr_resync;
6478 				}
6479 			} else
6480 				mddev->recovery_cp = MaxSector;
6481 		} else {
6482 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6483 				mddev->curr_resync = MaxSector;
6484 			list_for_each_entry(rdev, &mddev->disks, same_set)
6485 				if (rdev->raid_disk >= 0 &&
6486 				    !test_bit(Faulty, &rdev->flags) &&
6487 				    !test_bit(In_sync, &rdev->flags) &&
6488 				    rdev->recovery_offset < mddev->curr_resync)
6489 					rdev->recovery_offset = mddev->curr_resync;
6490 		}
6491 	}
6492 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6493 
6494  skip:
6495 	mddev->curr_resync = 0;
6496 	mddev->curr_resync_completed = 0;
6497 	mddev->resync_min = 0;
6498 	mddev->resync_max = MaxSector;
6499 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6500 	wake_up(&resync_wait);
6501 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6502 	md_wakeup_thread(mddev->thread);
6503 	return;
6504 
6505  interrupted:
6506 	/*
6507 	 * got a signal, exit.
6508 	 */
6509 	printk(KERN_INFO
6510 	       "md: md_do_sync() got signal ... exiting\n");
6511 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6512 	goto out;
6513 
6514 }
6515 EXPORT_SYMBOL_GPL(md_do_sync);
6516 
6517 
6518 static int remove_and_add_spares(mddev_t *mddev)
6519 {
6520 	mdk_rdev_t *rdev;
6521 	int spares = 0;
6522 
6523 	mddev->curr_resync_completed = 0;
6524 
6525 	list_for_each_entry(rdev, &mddev->disks, same_set)
6526 		if (rdev->raid_disk >= 0 &&
6527 		    !test_bit(Blocked, &rdev->flags) &&
6528 		    (test_bit(Faulty, &rdev->flags) ||
6529 		     ! test_bit(In_sync, &rdev->flags)) &&
6530 		    atomic_read(&rdev->nr_pending)==0) {
6531 			if (mddev->pers->hot_remove_disk(
6532 				    mddev, rdev->raid_disk)==0) {
6533 				char nm[20];
6534 				sprintf(nm,"rd%d", rdev->raid_disk);
6535 				sysfs_remove_link(&mddev->kobj, nm);
6536 				rdev->raid_disk = -1;
6537 			}
6538 		}
6539 
6540 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
6541 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6542 			if (rdev->raid_disk >= 0 &&
6543 			    !test_bit(In_sync, &rdev->flags) &&
6544 			    !test_bit(Blocked, &rdev->flags))
6545 				spares++;
6546 			if (rdev->raid_disk < 0
6547 			    && !test_bit(Faulty, &rdev->flags)) {
6548 				rdev->recovery_offset = 0;
6549 				if (mddev->pers->
6550 				    hot_add_disk(mddev, rdev) == 0) {
6551 					char nm[20];
6552 					sprintf(nm, "rd%d", rdev->raid_disk);
6553 					if (sysfs_create_link(&mddev->kobj,
6554 							      &rdev->kobj, nm))
6555 						printk(KERN_WARNING
6556 						       "md: cannot register "
6557 						       "%s for %s\n",
6558 						       nm, mdname(mddev));
6559 					spares++;
6560 					md_new_event(mddev);
6561 				} else
6562 					break;
6563 			}
6564 		}
6565 	}
6566 	return spares;
6567 }
6568 /*
6569  * This routine is regularly called by all per-raid-array threads to
6570  * deal with generic issues like resync and super-block update.
6571  * Raid personalities that don't have a thread (linear/raid0) do not
6572  * need this as they never do any recovery or update the superblock.
6573  *
6574  * It does not do any resync itself, but rather "forks" off other threads
6575  * to do that as needed.
6576  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
6577  * "->recovery" and create a thread at ->sync_thread.
6578  * When the thread finishes it sets MD_RECOVERY_DONE
6579  * and wakeups up this thread which will reap the thread and finish up.
6580  * This thread also removes any faulty devices (with nr_pending == 0).
6581  *
6582  * The overall approach is:
6583  *  1/ if the superblock needs updating, update it.
6584  *  2/ If a recovery thread is running, don't do anything else.
6585  *  3/ If recovery has finished, clean up, possibly marking spares active.
6586  *  4/ If there are any faulty devices, remove them.
6587  *  5/ If array is degraded, try to add spares devices
6588  *  6/ If array has spares or is not in-sync, start a resync thread.
6589  */
6590 void md_check_recovery(mddev_t *mddev)
6591 {
6592 	mdk_rdev_t *rdev;
6593 
6594 
6595 	if (mddev->bitmap)
6596 		bitmap_daemon_work(mddev->bitmap);
6597 
6598 	if (mddev->ro)
6599 		return;
6600 
6601 	if (signal_pending(current)) {
6602 		if (mddev->pers->sync_request && !mddev->external) {
6603 			printk(KERN_INFO "md: %s in immediate safe mode\n",
6604 			       mdname(mddev));
6605 			mddev->safemode = 2;
6606 		}
6607 		flush_signals(current);
6608 	}
6609 
6610 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
6611 		return;
6612 	if ( ! (
6613 		(mddev->flags && !mddev->external) ||
6614 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
6615 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
6616 		(mddev->external == 0 && mddev->safemode == 1) ||
6617 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
6618 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
6619 		))
6620 		return;
6621 
6622 	if (mddev_trylock(mddev)) {
6623 		int spares = 0;
6624 
6625 		if (mddev->ro) {
6626 			/* Only thing we do on a ro array is remove
6627 			 * failed devices.
6628 			 */
6629 			remove_and_add_spares(mddev);
6630 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6631 			goto unlock;
6632 		}
6633 
6634 		if (!mddev->external) {
6635 			int did_change = 0;
6636 			spin_lock_irq(&mddev->write_lock);
6637 			if (mddev->safemode &&
6638 			    !atomic_read(&mddev->writes_pending) &&
6639 			    !mddev->in_sync &&
6640 			    mddev->recovery_cp == MaxSector) {
6641 				mddev->in_sync = 1;
6642 				did_change = 1;
6643 				if (mddev->persistent)
6644 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6645 			}
6646 			if (mddev->safemode == 1)
6647 				mddev->safemode = 0;
6648 			spin_unlock_irq(&mddev->write_lock);
6649 			if (did_change)
6650 				sysfs_notify_dirent(mddev->sysfs_state);
6651 		}
6652 
6653 		if (mddev->flags)
6654 			md_update_sb(mddev, 0);
6655 
6656 		list_for_each_entry(rdev, &mddev->disks, same_set)
6657 			if (test_and_clear_bit(StateChanged, &rdev->flags))
6658 				sysfs_notify_dirent(rdev->sysfs_state);
6659 
6660 
6661 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
6662 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
6663 			/* resync/recovery still happening */
6664 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6665 			goto unlock;
6666 		}
6667 		if (mddev->sync_thread) {
6668 			/* resync has finished, collect result */
6669 			md_unregister_thread(mddev->sync_thread);
6670 			mddev->sync_thread = NULL;
6671 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
6672 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
6673 				/* success...*/
6674 				/* activate any spares */
6675 				if (mddev->pers->spare_active(mddev))
6676 					sysfs_notify(&mddev->kobj, NULL,
6677 						     "degraded");
6678 			}
6679 			if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6680 			    mddev->pers->finish_reshape)
6681 				mddev->pers->finish_reshape(mddev);
6682 			md_update_sb(mddev, 1);
6683 
6684 			/* if array is no-longer degraded, then any saved_raid_disk
6685 			 * information must be scrapped
6686 			 */
6687 			if (!mddev->degraded)
6688 				list_for_each_entry(rdev, &mddev->disks, same_set)
6689 					rdev->saved_raid_disk = -1;
6690 
6691 			mddev->recovery = 0;
6692 			/* flag recovery needed just to double check */
6693 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6694 			sysfs_notify_dirent(mddev->sysfs_action);
6695 			md_new_event(mddev);
6696 			goto unlock;
6697 		}
6698 		/* Set RUNNING before clearing NEEDED to avoid
6699 		 * any transients in the value of "sync_action".
6700 		 */
6701 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6702 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6703 		/* Clear some bits that don't mean anything, but
6704 		 * might be left set
6705 		 */
6706 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
6707 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
6708 
6709 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
6710 			goto unlock;
6711 		/* no recovery is running.
6712 		 * remove any failed drives, then
6713 		 * add spares if possible.
6714 		 * Spare are also removed and re-added, to allow
6715 		 * the personality to fail the re-add.
6716 		 */
6717 
6718 		if (mddev->reshape_position != MaxSector) {
6719 			if (mddev->pers->check_reshape == NULL ||
6720 			    mddev->pers->check_reshape(mddev) != 0)
6721 				/* Cannot proceed */
6722 				goto unlock;
6723 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6724 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6725 		} else if ((spares = remove_and_add_spares(mddev))) {
6726 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6727 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6728 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
6729 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6730 		} else if (mddev->recovery_cp < MaxSector) {
6731 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6732 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6733 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6734 			/* nothing to be done ... */
6735 			goto unlock;
6736 
6737 		if (mddev->pers->sync_request) {
6738 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
6739 				/* We are adding a device or devices to an array
6740 				 * which has the bitmap stored on all devices.
6741 				 * So make sure all bitmap pages get written
6742 				 */
6743 				bitmap_write_all(mddev->bitmap);
6744 			}
6745 			mddev->sync_thread = md_register_thread(md_do_sync,
6746 								mddev,
6747 								"%s_resync");
6748 			if (!mddev->sync_thread) {
6749 				printk(KERN_ERR "%s: could not start resync"
6750 					" thread...\n",
6751 					mdname(mddev));
6752 				/* leave the spares where they are, it shouldn't hurt */
6753 				mddev->recovery = 0;
6754 			} else
6755 				md_wakeup_thread(mddev->sync_thread);
6756 			sysfs_notify_dirent(mddev->sysfs_action);
6757 			md_new_event(mddev);
6758 		}
6759 	unlock:
6760 		if (!mddev->sync_thread) {
6761 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6762 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
6763 					       &mddev->recovery))
6764 				if (mddev->sysfs_action)
6765 					sysfs_notify_dirent(mddev->sysfs_action);
6766 		}
6767 		mddev_unlock(mddev);
6768 	}
6769 }
6770 
6771 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
6772 {
6773 	sysfs_notify_dirent(rdev->sysfs_state);
6774 	wait_event_timeout(rdev->blocked_wait,
6775 			   !test_bit(Blocked, &rdev->flags),
6776 			   msecs_to_jiffies(5000));
6777 	rdev_dec_pending(rdev, mddev);
6778 }
6779 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
6780 
6781 static int md_notify_reboot(struct notifier_block *this,
6782 			    unsigned long code, void *x)
6783 {
6784 	struct list_head *tmp;
6785 	mddev_t *mddev;
6786 
6787 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
6788 
6789 		printk(KERN_INFO "md: stopping all md devices.\n");
6790 
6791 		for_each_mddev(mddev, tmp)
6792 			if (mddev_trylock(mddev)) {
6793 				/* Force a switch to readonly even array
6794 				 * appears to still be in use.  Hence
6795 				 * the '100'.
6796 				 */
6797 				do_md_stop(mddev, 1, 100);
6798 				mddev_unlock(mddev);
6799 			}
6800 		/*
6801 		 * certain more exotic SCSI devices are known to be
6802 		 * volatile wrt too early system reboots. While the
6803 		 * right place to handle this issue is the given
6804 		 * driver, we do want to have a safe RAID driver ...
6805 		 */
6806 		mdelay(1000*1);
6807 	}
6808 	return NOTIFY_DONE;
6809 }
6810 
6811 static struct notifier_block md_notifier = {
6812 	.notifier_call	= md_notify_reboot,
6813 	.next		= NULL,
6814 	.priority	= INT_MAX, /* before any real devices */
6815 };
6816 
6817 static void md_geninit(void)
6818 {
6819 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
6820 
6821 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
6822 }
6823 
6824 static int __init md_init(void)
6825 {
6826 	if (register_blkdev(MD_MAJOR, "md"))
6827 		return -1;
6828 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
6829 		unregister_blkdev(MD_MAJOR, "md");
6830 		return -1;
6831 	}
6832 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
6833 			    md_probe, NULL, NULL);
6834 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
6835 			    md_probe, NULL, NULL);
6836 
6837 	register_reboot_notifier(&md_notifier);
6838 	raid_table_header = register_sysctl_table(raid_root_table);
6839 
6840 	md_geninit();
6841 	return 0;
6842 }
6843 
6844 
6845 #ifndef MODULE
6846 
6847 /*
6848  * Searches all registered partitions for autorun RAID arrays
6849  * at boot time.
6850  */
6851 
6852 static LIST_HEAD(all_detected_devices);
6853 struct detected_devices_node {
6854 	struct list_head list;
6855 	dev_t dev;
6856 };
6857 
6858 void md_autodetect_dev(dev_t dev)
6859 {
6860 	struct detected_devices_node *node_detected_dev;
6861 
6862 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
6863 	if (node_detected_dev) {
6864 		node_detected_dev->dev = dev;
6865 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
6866 	} else {
6867 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
6868 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
6869 	}
6870 }
6871 
6872 
6873 static void autostart_arrays(int part)
6874 {
6875 	mdk_rdev_t *rdev;
6876 	struct detected_devices_node *node_detected_dev;
6877 	dev_t dev;
6878 	int i_scanned, i_passed;
6879 
6880 	i_scanned = 0;
6881 	i_passed = 0;
6882 
6883 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
6884 
6885 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
6886 		i_scanned++;
6887 		node_detected_dev = list_entry(all_detected_devices.next,
6888 					struct detected_devices_node, list);
6889 		list_del(&node_detected_dev->list);
6890 		dev = node_detected_dev->dev;
6891 		kfree(node_detected_dev);
6892 		rdev = md_import_device(dev,0, 90);
6893 		if (IS_ERR(rdev))
6894 			continue;
6895 
6896 		if (test_bit(Faulty, &rdev->flags)) {
6897 			MD_BUG();
6898 			continue;
6899 		}
6900 		set_bit(AutoDetected, &rdev->flags);
6901 		list_add(&rdev->same_set, &pending_raid_disks);
6902 		i_passed++;
6903 	}
6904 
6905 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
6906 						i_scanned, i_passed);
6907 
6908 	autorun_devices(part);
6909 }
6910 
6911 #endif /* !MODULE */
6912 
6913 static __exit void md_exit(void)
6914 {
6915 	mddev_t *mddev;
6916 	struct list_head *tmp;
6917 
6918 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
6919 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
6920 
6921 	unregister_blkdev(MD_MAJOR,"md");
6922 	unregister_blkdev(mdp_major, "mdp");
6923 	unregister_reboot_notifier(&md_notifier);
6924 	unregister_sysctl_table(raid_table_header);
6925 	remove_proc_entry("mdstat", NULL);
6926 	for_each_mddev(mddev, tmp) {
6927 		export_array(mddev);
6928 		mddev->hold_active = 0;
6929 	}
6930 }
6931 
6932 subsys_initcall(md_init);
6933 module_exit(md_exit)
6934 
6935 static int get_ro(char *buffer, struct kernel_param *kp)
6936 {
6937 	return sprintf(buffer, "%d", start_readonly);
6938 }
6939 static int set_ro(const char *val, struct kernel_param *kp)
6940 {
6941 	char *e;
6942 	int num = simple_strtoul(val, &e, 10);
6943 	if (*val && (*e == '\0' || *e == '\n')) {
6944 		start_readonly = num;
6945 		return 0;
6946 	}
6947 	return -EINVAL;
6948 }
6949 
6950 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
6951 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
6952 
6953 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
6954 
6955 EXPORT_SYMBOL(register_md_personality);
6956 EXPORT_SYMBOL(unregister_md_personality);
6957 EXPORT_SYMBOL(md_error);
6958 EXPORT_SYMBOL(md_done_sync);
6959 EXPORT_SYMBOL(md_write_start);
6960 EXPORT_SYMBOL(md_write_end);
6961 EXPORT_SYMBOL(md_register_thread);
6962 EXPORT_SYMBOL(md_unregister_thread);
6963 EXPORT_SYMBOL(md_wakeup_thread);
6964 EXPORT_SYMBOL(md_check_recovery);
6965 MODULE_LICENSE("GPL");
6966 MODULE_ALIAS("md");
6967 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
6968