xref: /linux/drivers/md/md.c (revision 273b281fa22c293963ee3e6eec418f5dda2dbc83)
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 		.procname	= "speed_limit_min",
102 		.data		= &sysctl_speed_limit_min,
103 		.maxlen		= sizeof(int),
104 		.mode		= S_IRUGO|S_IWUSR,
105 		.proc_handler	= proc_dointvec,
106 	},
107 	{
108 		.procname	= "speed_limit_max",
109 		.data		= &sysctl_speed_limit_max,
110 		.maxlen		= sizeof(int),
111 		.mode		= S_IRUGO|S_IWUSR,
112 		.proc_handler	= proc_dointvec,
113 	},
114 	{ }
115 };
116 
117 static ctl_table raid_dir_table[] = {
118 	{
119 		.procname	= "raid",
120 		.maxlen		= 0,
121 		.mode		= S_IRUGO|S_IXUGO,
122 		.child		= raid_table,
123 	},
124 	{ }
125 };
126 
127 static ctl_table raid_root_table[] = {
128 	{
129 		.procname	= "dev",
130 		.maxlen		= 0,
131 		.mode		= 0555,
132 		.child		= raid_dir_table,
133 	},
134 	{  }
135 };
136 
137 static const struct block_device_operations md_fops;
138 
139 static int start_readonly;
140 
141 /*
142  * We have a system wide 'event count' that is incremented
143  * on any 'interesting' event, and readers of /proc/mdstat
144  * can use 'poll' or 'select' to find out when the event
145  * count increases.
146  *
147  * Events are:
148  *  start array, stop array, error, add device, remove device,
149  *  start build, activate spare
150  */
151 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
152 static atomic_t md_event_count;
153 void md_new_event(mddev_t *mddev)
154 {
155 	atomic_inc(&md_event_count);
156 	wake_up(&md_event_waiters);
157 }
158 EXPORT_SYMBOL_GPL(md_new_event);
159 
160 /* Alternate version that can be called from interrupts
161  * when calling sysfs_notify isn't needed.
162  */
163 static void md_new_event_inintr(mddev_t *mddev)
164 {
165 	atomic_inc(&md_event_count);
166 	wake_up(&md_event_waiters);
167 }
168 
169 /*
170  * Enables to iterate over all existing md arrays
171  * all_mddevs_lock protects this list.
172  */
173 static LIST_HEAD(all_mddevs);
174 static DEFINE_SPINLOCK(all_mddevs_lock);
175 
176 
177 /*
178  * iterates through all used mddevs in the system.
179  * We take care to grab the all_mddevs_lock whenever navigating
180  * the list, and to always hold a refcount when unlocked.
181  * Any code which breaks out of this loop while own
182  * a reference to the current mddev and must mddev_put it.
183  */
184 #define for_each_mddev(mddev,tmp)					\
185 									\
186 	for (({ spin_lock(&all_mddevs_lock); 				\
187 		tmp = all_mddevs.next;					\
188 		mddev = NULL;});					\
189 	     ({ if (tmp != &all_mddevs)					\
190 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
191 		spin_unlock(&all_mddevs_lock);				\
192 		if (mddev) mddev_put(mddev);				\
193 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
194 		tmp != &all_mddevs;});					\
195 	     ({ spin_lock(&all_mddevs_lock);				\
196 		tmp = tmp->next;})					\
197 		)
198 
199 
200 /* Rather than calling directly into the personality make_request function,
201  * IO requests come here first so that we can check if the device is
202  * being suspended pending a reconfiguration.
203  * We hold a refcount over the call to ->make_request.  By the time that
204  * call has finished, the bio has been linked into some internal structure
205  * and so is visible to ->quiesce(), so we don't need the refcount any more.
206  */
207 static int md_make_request(struct request_queue *q, struct bio *bio)
208 {
209 	mddev_t *mddev = q->queuedata;
210 	int rv;
211 	if (mddev == NULL || mddev->pers == NULL) {
212 		bio_io_error(bio);
213 		return 0;
214 	}
215 	rcu_read_lock();
216 	if (mddev->suspended) {
217 		DEFINE_WAIT(__wait);
218 		for (;;) {
219 			prepare_to_wait(&mddev->sb_wait, &__wait,
220 					TASK_UNINTERRUPTIBLE);
221 			if (!mddev->suspended)
222 				break;
223 			rcu_read_unlock();
224 			schedule();
225 			rcu_read_lock();
226 		}
227 		finish_wait(&mddev->sb_wait, &__wait);
228 	}
229 	atomic_inc(&mddev->active_io);
230 	rcu_read_unlock();
231 	rv = mddev->pers->make_request(q, bio);
232 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
233 		wake_up(&mddev->sb_wait);
234 
235 	return rv;
236 }
237 
238 static void mddev_suspend(mddev_t *mddev)
239 {
240 	BUG_ON(mddev->suspended);
241 	mddev->suspended = 1;
242 	synchronize_rcu();
243 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
244 	mddev->pers->quiesce(mddev, 1);
245 	md_unregister_thread(mddev->thread);
246 	mddev->thread = NULL;
247 	/* we now know that no code is executing in the personality module,
248 	 * except possibly the tail end of a ->bi_end_io function, but that
249 	 * is certain to complete before the module has a chance to get
250 	 * unloaded
251 	 */
252 }
253 
254 static void mddev_resume(mddev_t *mddev)
255 {
256 	mddev->suspended = 0;
257 	wake_up(&mddev->sb_wait);
258 	mddev->pers->quiesce(mddev, 0);
259 }
260 
261 int mddev_congested(mddev_t *mddev, int bits)
262 {
263 	return mddev->suspended;
264 }
265 EXPORT_SYMBOL(mddev_congested);
266 
267 
268 static inline mddev_t *mddev_get(mddev_t *mddev)
269 {
270 	atomic_inc(&mddev->active);
271 	return mddev;
272 }
273 
274 static void mddev_delayed_delete(struct work_struct *ws);
275 
276 static void mddev_put(mddev_t *mddev)
277 {
278 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
279 		return;
280 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
281 	    !mddev->hold_active) {
282 		list_del(&mddev->all_mddevs);
283 		if (mddev->gendisk) {
284 			/* we did a probe so need to clean up.
285 			 * Call schedule_work inside the spinlock
286 			 * so that flush_scheduled_work() after
287 			 * mddev_find will succeed in waiting for the
288 			 * work to be done.
289 			 */
290 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
291 			schedule_work(&mddev->del_work);
292 		} else
293 			kfree(mddev);
294 	}
295 	spin_unlock(&all_mddevs_lock);
296 }
297 
298 static mddev_t * mddev_find(dev_t unit)
299 {
300 	mddev_t *mddev, *new = NULL;
301 
302  retry:
303 	spin_lock(&all_mddevs_lock);
304 
305 	if (unit) {
306 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
307 			if (mddev->unit == unit) {
308 				mddev_get(mddev);
309 				spin_unlock(&all_mddevs_lock);
310 				kfree(new);
311 				return mddev;
312 			}
313 
314 		if (new) {
315 			list_add(&new->all_mddevs, &all_mddevs);
316 			spin_unlock(&all_mddevs_lock);
317 			new->hold_active = UNTIL_IOCTL;
318 			return new;
319 		}
320 	} else if (new) {
321 		/* find an unused unit number */
322 		static int next_minor = 512;
323 		int start = next_minor;
324 		int is_free = 0;
325 		int dev = 0;
326 		while (!is_free) {
327 			dev = MKDEV(MD_MAJOR, next_minor);
328 			next_minor++;
329 			if (next_minor > MINORMASK)
330 				next_minor = 0;
331 			if (next_minor == start) {
332 				/* Oh dear, all in use. */
333 				spin_unlock(&all_mddevs_lock);
334 				kfree(new);
335 				return NULL;
336 			}
337 
338 			is_free = 1;
339 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
340 				if (mddev->unit == dev) {
341 					is_free = 0;
342 					break;
343 				}
344 		}
345 		new->unit = dev;
346 		new->md_minor = MINOR(dev);
347 		new->hold_active = UNTIL_STOP;
348 		list_add(&new->all_mddevs, &all_mddevs);
349 		spin_unlock(&all_mddevs_lock);
350 		return new;
351 	}
352 	spin_unlock(&all_mddevs_lock);
353 
354 	new = kzalloc(sizeof(*new), GFP_KERNEL);
355 	if (!new)
356 		return NULL;
357 
358 	new->unit = unit;
359 	if (MAJOR(unit) == MD_MAJOR)
360 		new->md_minor = MINOR(unit);
361 	else
362 		new->md_minor = MINOR(unit) >> MdpMinorShift;
363 
364 	mutex_init(&new->open_mutex);
365 	mutex_init(&new->reconfig_mutex);
366 	INIT_LIST_HEAD(&new->disks);
367 	INIT_LIST_HEAD(&new->all_mddevs);
368 	init_timer(&new->safemode_timer);
369 	atomic_set(&new->active, 1);
370 	atomic_set(&new->openers, 0);
371 	atomic_set(&new->active_io, 0);
372 	spin_lock_init(&new->write_lock);
373 	init_waitqueue_head(&new->sb_wait);
374 	init_waitqueue_head(&new->recovery_wait);
375 	new->reshape_position = MaxSector;
376 	new->resync_min = 0;
377 	new->resync_max = MaxSector;
378 	new->level = LEVEL_NONE;
379 
380 	goto retry;
381 }
382 
383 static inline int mddev_lock(mddev_t * mddev)
384 {
385 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
386 }
387 
388 static inline int mddev_is_locked(mddev_t *mddev)
389 {
390 	return mutex_is_locked(&mddev->reconfig_mutex);
391 }
392 
393 static inline int mddev_trylock(mddev_t * mddev)
394 {
395 	return mutex_trylock(&mddev->reconfig_mutex);
396 }
397 
398 static inline void mddev_unlock(mddev_t * mddev)
399 {
400 	mutex_unlock(&mddev->reconfig_mutex);
401 
402 	md_wakeup_thread(mddev->thread);
403 }
404 
405 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
406 {
407 	mdk_rdev_t *rdev;
408 
409 	list_for_each_entry(rdev, &mddev->disks, same_set)
410 		if (rdev->desc_nr == nr)
411 			return rdev;
412 
413 	return NULL;
414 }
415 
416 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
417 {
418 	mdk_rdev_t *rdev;
419 
420 	list_for_each_entry(rdev, &mddev->disks, same_set)
421 		if (rdev->bdev->bd_dev == dev)
422 			return rdev;
423 
424 	return NULL;
425 }
426 
427 static struct mdk_personality *find_pers(int level, char *clevel)
428 {
429 	struct mdk_personality *pers;
430 	list_for_each_entry(pers, &pers_list, list) {
431 		if (level != LEVEL_NONE && pers->level == level)
432 			return pers;
433 		if (strcmp(pers->name, clevel)==0)
434 			return pers;
435 	}
436 	return NULL;
437 }
438 
439 /* return the offset of the super block in 512byte sectors */
440 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
441 {
442 	sector_t num_sectors = bdev->bd_inode->i_size / 512;
443 	return MD_NEW_SIZE_SECTORS(num_sectors);
444 }
445 
446 static int alloc_disk_sb(mdk_rdev_t * rdev)
447 {
448 	if (rdev->sb_page)
449 		MD_BUG();
450 
451 	rdev->sb_page = alloc_page(GFP_KERNEL);
452 	if (!rdev->sb_page) {
453 		printk(KERN_ALERT "md: out of memory.\n");
454 		return -ENOMEM;
455 	}
456 
457 	return 0;
458 }
459 
460 static void free_disk_sb(mdk_rdev_t * rdev)
461 {
462 	if (rdev->sb_page) {
463 		put_page(rdev->sb_page);
464 		rdev->sb_loaded = 0;
465 		rdev->sb_page = NULL;
466 		rdev->sb_start = 0;
467 		rdev->sectors = 0;
468 	}
469 }
470 
471 
472 static void super_written(struct bio *bio, int error)
473 {
474 	mdk_rdev_t *rdev = bio->bi_private;
475 	mddev_t *mddev = rdev->mddev;
476 
477 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
478 		printk("md: super_written gets error=%d, uptodate=%d\n",
479 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
480 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
481 		md_error(mddev, rdev);
482 	}
483 
484 	if (atomic_dec_and_test(&mddev->pending_writes))
485 		wake_up(&mddev->sb_wait);
486 	bio_put(bio);
487 }
488 
489 static void super_written_barrier(struct bio *bio, int error)
490 {
491 	struct bio *bio2 = bio->bi_private;
492 	mdk_rdev_t *rdev = bio2->bi_private;
493 	mddev_t *mddev = rdev->mddev;
494 
495 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
496 	    error == -EOPNOTSUPP) {
497 		unsigned long flags;
498 		/* barriers don't appear to be supported :-( */
499 		set_bit(BarriersNotsupp, &rdev->flags);
500 		mddev->barriers_work = 0;
501 		spin_lock_irqsave(&mddev->write_lock, flags);
502 		bio2->bi_next = mddev->biolist;
503 		mddev->biolist = bio2;
504 		spin_unlock_irqrestore(&mddev->write_lock, flags);
505 		wake_up(&mddev->sb_wait);
506 		bio_put(bio);
507 	} else {
508 		bio_put(bio2);
509 		bio->bi_private = rdev;
510 		super_written(bio, error);
511 	}
512 }
513 
514 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
515 		   sector_t sector, int size, struct page *page)
516 {
517 	/* write first size bytes of page to sector of rdev
518 	 * Increment mddev->pending_writes before returning
519 	 * and decrement it on completion, waking up sb_wait
520 	 * if zero is reached.
521 	 * If an error occurred, call md_error
522 	 *
523 	 * As we might need to resubmit the request if BIO_RW_BARRIER
524 	 * causes ENOTSUPP, we allocate a spare bio...
525 	 */
526 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
527 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNCIO) | (1<<BIO_RW_UNPLUG);
528 
529 	bio->bi_bdev = rdev->bdev;
530 	bio->bi_sector = sector;
531 	bio_add_page(bio, page, size, 0);
532 	bio->bi_private = rdev;
533 	bio->bi_end_io = super_written;
534 	bio->bi_rw = rw;
535 
536 	atomic_inc(&mddev->pending_writes);
537 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
538 		struct bio *rbio;
539 		rw |= (1<<BIO_RW_BARRIER);
540 		rbio = bio_clone(bio, GFP_NOIO);
541 		rbio->bi_private = bio;
542 		rbio->bi_end_io = super_written_barrier;
543 		submit_bio(rw, rbio);
544 	} else
545 		submit_bio(rw, bio);
546 }
547 
548 void md_super_wait(mddev_t *mddev)
549 {
550 	/* wait for all superblock writes that were scheduled to complete.
551 	 * if any had to be retried (due to BARRIER problems), retry them
552 	 */
553 	DEFINE_WAIT(wq);
554 	for(;;) {
555 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
556 		if (atomic_read(&mddev->pending_writes)==0)
557 			break;
558 		while (mddev->biolist) {
559 			struct bio *bio;
560 			spin_lock_irq(&mddev->write_lock);
561 			bio = mddev->biolist;
562 			mddev->biolist = bio->bi_next ;
563 			bio->bi_next = NULL;
564 			spin_unlock_irq(&mddev->write_lock);
565 			submit_bio(bio->bi_rw, bio);
566 		}
567 		schedule();
568 	}
569 	finish_wait(&mddev->sb_wait, &wq);
570 }
571 
572 static void bi_complete(struct bio *bio, int error)
573 {
574 	complete((struct completion*)bio->bi_private);
575 }
576 
577 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
578 		   struct page *page, int rw)
579 {
580 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
581 	struct completion event;
582 	int ret;
583 
584 	rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
585 
586 	bio->bi_bdev = bdev;
587 	bio->bi_sector = sector;
588 	bio_add_page(bio, page, size, 0);
589 	init_completion(&event);
590 	bio->bi_private = &event;
591 	bio->bi_end_io = bi_complete;
592 	submit_bio(rw, bio);
593 	wait_for_completion(&event);
594 
595 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
596 	bio_put(bio);
597 	return ret;
598 }
599 EXPORT_SYMBOL_GPL(sync_page_io);
600 
601 static int read_disk_sb(mdk_rdev_t * rdev, int size)
602 {
603 	char b[BDEVNAME_SIZE];
604 	if (!rdev->sb_page) {
605 		MD_BUG();
606 		return -EINVAL;
607 	}
608 	if (rdev->sb_loaded)
609 		return 0;
610 
611 
612 	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
613 		goto fail;
614 	rdev->sb_loaded = 1;
615 	return 0;
616 
617 fail:
618 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
619 		bdevname(rdev->bdev,b));
620 	return -EINVAL;
621 }
622 
623 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
624 {
625 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
626 		sb1->set_uuid1 == sb2->set_uuid1 &&
627 		sb1->set_uuid2 == sb2->set_uuid2 &&
628 		sb1->set_uuid3 == sb2->set_uuid3;
629 }
630 
631 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
632 {
633 	int ret;
634 	mdp_super_t *tmp1, *tmp2;
635 
636 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
637 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
638 
639 	if (!tmp1 || !tmp2) {
640 		ret = 0;
641 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
642 		goto abort;
643 	}
644 
645 	*tmp1 = *sb1;
646 	*tmp2 = *sb2;
647 
648 	/*
649 	 * nr_disks is not constant
650 	 */
651 	tmp1->nr_disks = 0;
652 	tmp2->nr_disks = 0;
653 
654 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
655 abort:
656 	kfree(tmp1);
657 	kfree(tmp2);
658 	return ret;
659 }
660 
661 
662 static u32 md_csum_fold(u32 csum)
663 {
664 	csum = (csum & 0xffff) + (csum >> 16);
665 	return (csum & 0xffff) + (csum >> 16);
666 }
667 
668 static unsigned int calc_sb_csum(mdp_super_t * sb)
669 {
670 	u64 newcsum = 0;
671 	u32 *sb32 = (u32*)sb;
672 	int i;
673 	unsigned int disk_csum, csum;
674 
675 	disk_csum = sb->sb_csum;
676 	sb->sb_csum = 0;
677 
678 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
679 		newcsum += sb32[i];
680 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
681 
682 
683 #ifdef CONFIG_ALPHA
684 	/* This used to use csum_partial, which was wrong for several
685 	 * reasons including that different results are returned on
686 	 * different architectures.  It isn't critical that we get exactly
687 	 * the same return value as before (we always csum_fold before
688 	 * testing, and that removes any differences).  However as we
689 	 * know that csum_partial always returned a 16bit value on
690 	 * alphas, do a fold to maximise conformity to previous behaviour.
691 	 */
692 	sb->sb_csum = md_csum_fold(disk_csum);
693 #else
694 	sb->sb_csum = disk_csum;
695 #endif
696 	return csum;
697 }
698 
699 
700 /*
701  * Handle superblock details.
702  * We want to be able to handle multiple superblock formats
703  * so we have a common interface to them all, and an array of
704  * different handlers.
705  * We rely on user-space to write the initial superblock, and support
706  * reading and updating of superblocks.
707  * Interface methods are:
708  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
709  *      loads and validates a superblock on dev.
710  *      if refdev != NULL, compare superblocks on both devices
711  *    Return:
712  *      0 - dev has a superblock that is compatible with refdev
713  *      1 - dev has a superblock that is compatible and newer than refdev
714  *          so dev should be used as the refdev in future
715  *     -EINVAL superblock incompatible or invalid
716  *     -othererror e.g. -EIO
717  *
718  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
719  *      Verify that dev is acceptable into mddev.
720  *       The first time, mddev->raid_disks will be 0, and data from
721  *       dev should be merged in.  Subsequent calls check that dev
722  *       is new enough.  Return 0 or -EINVAL
723  *
724  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
725  *     Update the superblock for rdev with data in mddev
726  *     This does not write to disc.
727  *
728  */
729 
730 struct super_type  {
731 	char		    *name;
732 	struct module	    *owner;
733 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
734 					  int minor_version);
735 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
736 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
737 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
738 						sector_t num_sectors);
739 };
740 
741 /*
742  * Check that the given mddev has no bitmap.
743  *
744  * This function is called from the run method of all personalities that do not
745  * support bitmaps. It prints an error message and returns non-zero if mddev
746  * has a bitmap. Otherwise, it returns 0.
747  *
748  */
749 int md_check_no_bitmap(mddev_t *mddev)
750 {
751 	if (!mddev->bitmap_file && !mddev->bitmap_offset)
752 		return 0;
753 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
754 		mdname(mddev), mddev->pers->name);
755 	return 1;
756 }
757 EXPORT_SYMBOL(md_check_no_bitmap);
758 
759 /*
760  * load_super for 0.90.0
761  */
762 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
763 {
764 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
765 	mdp_super_t *sb;
766 	int ret;
767 
768 	/*
769 	 * Calculate the position of the superblock (512byte sectors),
770 	 * it's at the end of the disk.
771 	 *
772 	 * It also happens to be a multiple of 4Kb.
773 	 */
774 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
775 
776 	ret = read_disk_sb(rdev, MD_SB_BYTES);
777 	if (ret) return ret;
778 
779 	ret = -EINVAL;
780 
781 	bdevname(rdev->bdev, b);
782 	sb = (mdp_super_t*)page_address(rdev->sb_page);
783 
784 	if (sb->md_magic != MD_SB_MAGIC) {
785 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
786 		       b);
787 		goto abort;
788 	}
789 
790 	if (sb->major_version != 0 ||
791 	    sb->minor_version < 90 ||
792 	    sb->minor_version > 91) {
793 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
794 			sb->major_version, sb->minor_version,
795 			b);
796 		goto abort;
797 	}
798 
799 	if (sb->raid_disks <= 0)
800 		goto abort;
801 
802 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
803 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
804 			b);
805 		goto abort;
806 	}
807 
808 	rdev->preferred_minor = sb->md_minor;
809 	rdev->data_offset = 0;
810 	rdev->sb_size = MD_SB_BYTES;
811 
812 	if (sb->level == LEVEL_MULTIPATH)
813 		rdev->desc_nr = -1;
814 	else
815 		rdev->desc_nr = sb->this_disk.number;
816 
817 	if (!refdev) {
818 		ret = 1;
819 	} else {
820 		__u64 ev1, ev2;
821 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
822 		if (!uuid_equal(refsb, sb)) {
823 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
824 				b, bdevname(refdev->bdev,b2));
825 			goto abort;
826 		}
827 		if (!sb_equal(refsb, sb)) {
828 			printk(KERN_WARNING "md: %s has same UUID"
829 			       " but different superblock to %s\n",
830 			       b, bdevname(refdev->bdev, b2));
831 			goto abort;
832 		}
833 		ev1 = md_event(sb);
834 		ev2 = md_event(refsb);
835 		if (ev1 > ev2)
836 			ret = 1;
837 		else
838 			ret = 0;
839 	}
840 	rdev->sectors = rdev->sb_start;
841 
842 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
843 		/* "this cannot possibly happen" ... */
844 		ret = -EINVAL;
845 
846  abort:
847 	return ret;
848 }
849 
850 /*
851  * validate_super for 0.90.0
852  */
853 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
854 {
855 	mdp_disk_t *desc;
856 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
857 	__u64 ev1 = md_event(sb);
858 
859 	rdev->raid_disk = -1;
860 	clear_bit(Faulty, &rdev->flags);
861 	clear_bit(In_sync, &rdev->flags);
862 	clear_bit(WriteMostly, &rdev->flags);
863 	clear_bit(BarriersNotsupp, &rdev->flags);
864 
865 	if (mddev->raid_disks == 0) {
866 		mddev->major_version = 0;
867 		mddev->minor_version = sb->minor_version;
868 		mddev->patch_version = sb->patch_version;
869 		mddev->external = 0;
870 		mddev->chunk_sectors = sb->chunk_size >> 9;
871 		mddev->ctime = sb->ctime;
872 		mddev->utime = sb->utime;
873 		mddev->level = sb->level;
874 		mddev->clevel[0] = 0;
875 		mddev->layout = sb->layout;
876 		mddev->raid_disks = sb->raid_disks;
877 		mddev->dev_sectors = sb->size * 2;
878 		mddev->events = ev1;
879 		mddev->bitmap_offset = 0;
880 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
881 
882 		if (mddev->minor_version >= 91) {
883 			mddev->reshape_position = sb->reshape_position;
884 			mddev->delta_disks = sb->delta_disks;
885 			mddev->new_level = sb->new_level;
886 			mddev->new_layout = sb->new_layout;
887 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
888 		} else {
889 			mddev->reshape_position = MaxSector;
890 			mddev->delta_disks = 0;
891 			mddev->new_level = mddev->level;
892 			mddev->new_layout = mddev->layout;
893 			mddev->new_chunk_sectors = mddev->chunk_sectors;
894 		}
895 
896 		if (sb->state & (1<<MD_SB_CLEAN))
897 			mddev->recovery_cp = MaxSector;
898 		else {
899 			if (sb->events_hi == sb->cp_events_hi &&
900 				sb->events_lo == sb->cp_events_lo) {
901 				mddev->recovery_cp = sb->recovery_cp;
902 			} else
903 				mddev->recovery_cp = 0;
904 		}
905 
906 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
907 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
908 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
909 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
910 
911 		mddev->max_disks = MD_SB_DISKS;
912 
913 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
914 		    mddev->bitmap_file == NULL)
915 			mddev->bitmap_offset = mddev->default_bitmap_offset;
916 
917 	} else if (mddev->pers == NULL) {
918 		/* Insist on good event counter while assembling */
919 		++ev1;
920 		if (ev1 < mddev->events)
921 			return -EINVAL;
922 	} else if (mddev->bitmap) {
923 		/* if adding to array with a bitmap, then we can accept an
924 		 * older device ... but not too old.
925 		 */
926 		if (ev1 < mddev->bitmap->events_cleared)
927 			return 0;
928 	} else {
929 		if (ev1 < mddev->events)
930 			/* just a hot-add of a new device, leave raid_disk at -1 */
931 			return 0;
932 	}
933 
934 	if (mddev->level != LEVEL_MULTIPATH) {
935 		desc = sb->disks + rdev->desc_nr;
936 
937 		if (desc->state & (1<<MD_DISK_FAULTY))
938 			set_bit(Faulty, &rdev->flags);
939 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
940 			    desc->raid_disk < mddev->raid_disks */) {
941 			set_bit(In_sync, &rdev->flags);
942 			rdev->raid_disk = desc->raid_disk;
943 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
944 			/* active but not in sync implies recovery up to
945 			 * reshape position.  We don't know exactly where
946 			 * that is, so set to zero for now */
947 			if (mddev->minor_version >= 91) {
948 				rdev->recovery_offset = 0;
949 				rdev->raid_disk = desc->raid_disk;
950 			}
951 		}
952 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
953 			set_bit(WriteMostly, &rdev->flags);
954 	} else /* MULTIPATH are always insync */
955 		set_bit(In_sync, &rdev->flags);
956 	return 0;
957 }
958 
959 /*
960  * sync_super for 0.90.0
961  */
962 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
963 {
964 	mdp_super_t *sb;
965 	mdk_rdev_t *rdev2;
966 	int next_spare = mddev->raid_disks;
967 
968 
969 	/* make rdev->sb match mddev data..
970 	 *
971 	 * 1/ zero out disks
972 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
973 	 * 3/ any empty disks < next_spare become removed
974 	 *
975 	 * disks[0] gets initialised to REMOVED because
976 	 * we cannot be sure from other fields if it has
977 	 * been initialised or not.
978 	 */
979 	int i;
980 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
981 
982 	rdev->sb_size = MD_SB_BYTES;
983 
984 	sb = (mdp_super_t*)page_address(rdev->sb_page);
985 
986 	memset(sb, 0, sizeof(*sb));
987 
988 	sb->md_magic = MD_SB_MAGIC;
989 	sb->major_version = mddev->major_version;
990 	sb->patch_version = mddev->patch_version;
991 	sb->gvalid_words  = 0; /* ignored */
992 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
993 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
994 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
995 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
996 
997 	sb->ctime = mddev->ctime;
998 	sb->level = mddev->level;
999 	sb->size = mddev->dev_sectors / 2;
1000 	sb->raid_disks = mddev->raid_disks;
1001 	sb->md_minor = mddev->md_minor;
1002 	sb->not_persistent = 0;
1003 	sb->utime = mddev->utime;
1004 	sb->state = 0;
1005 	sb->events_hi = (mddev->events>>32);
1006 	sb->events_lo = (u32)mddev->events;
1007 
1008 	if (mddev->reshape_position == MaxSector)
1009 		sb->minor_version = 90;
1010 	else {
1011 		sb->minor_version = 91;
1012 		sb->reshape_position = mddev->reshape_position;
1013 		sb->new_level = mddev->new_level;
1014 		sb->delta_disks = mddev->delta_disks;
1015 		sb->new_layout = mddev->new_layout;
1016 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1017 	}
1018 	mddev->minor_version = sb->minor_version;
1019 	if (mddev->in_sync)
1020 	{
1021 		sb->recovery_cp = mddev->recovery_cp;
1022 		sb->cp_events_hi = (mddev->events>>32);
1023 		sb->cp_events_lo = (u32)mddev->events;
1024 		if (mddev->recovery_cp == MaxSector)
1025 			sb->state = (1<< MD_SB_CLEAN);
1026 	} else
1027 		sb->recovery_cp = 0;
1028 
1029 	sb->layout = mddev->layout;
1030 	sb->chunk_size = mddev->chunk_sectors << 9;
1031 
1032 	if (mddev->bitmap && mddev->bitmap_file == NULL)
1033 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1034 
1035 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1036 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1037 		mdp_disk_t *d;
1038 		int desc_nr;
1039 		int is_active = test_bit(In_sync, &rdev2->flags);
1040 
1041 		if (rdev2->raid_disk >= 0 &&
1042 		    sb->minor_version >= 91)
1043 			/* we have nowhere to store the recovery_offset,
1044 			 * but if it is not below the reshape_position,
1045 			 * we can piggy-back on that.
1046 			 */
1047 			is_active = 1;
1048 		if (rdev2->raid_disk < 0 ||
1049 		    test_bit(Faulty, &rdev2->flags))
1050 			is_active = 0;
1051 		if (is_active)
1052 			desc_nr = rdev2->raid_disk;
1053 		else
1054 			desc_nr = next_spare++;
1055 		rdev2->desc_nr = desc_nr;
1056 		d = &sb->disks[rdev2->desc_nr];
1057 		nr_disks++;
1058 		d->number = rdev2->desc_nr;
1059 		d->major = MAJOR(rdev2->bdev->bd_dev);
1060 		d->minor = MINOR(rdev2->bdev->bd_dev);
1061 		if (is_active)
1062 			d->raid_disk = rdev2->raid_disk;
1063 		else
1064 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1065 		if (test_bit(Faulty, &rdev2->flags))
1066 			d->state = (1<<MD_DISK_FAULTY);
1067 		else if (is_active) {
1068 			d->state = (1<<MD_DISK_ACTIVE);
1069 			if (test_bit(In_sync, &rdev2->flags))
1070 				d->state |= (1<<MD_DISK_SYNC);
1071 			active++;
1072 			working++;
1073 		} else {
1074 			d->state = 0;
1075 			spare++;
1076 			working++;
1077 		}
1078 		if (test_bit(WriteMostly, &rdev2->flags))
1079 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1080 	}
1081 	/* now set the "removed" and "faulty" bits on any missing devices */
1082 	for (i=0 ; i < mddev->raid_disks ; i++) {
1083 		mdp_disk_t *d = &sb->disks[i];
1084 		if (d->state == 0 && d->number == 0) {
1085 			d->number = i;
1086 			d->raid_disk = i;
1087 			d->state = (1<<MD_DISK_REMOVED);
1088 			d->state |= (1<<MD_DISK_FAULTY);
1089 			failed++;
1090 		}
1091 	}
1092 	sb->nr_disks = nr_disks;
1093 	sb->active_disks = active;
1094 	sb->working_disks = working;
1095 	sb->failed_disks = failed;
1096 	sb->spare_disks = spare;
1097 
1098 	sb->this_disk = sb->disks[rdev->desc_nr];
1099 	sb->sb_csum = calc_sb_csum(sb);
1100 }
1101 
1102 /*
1103  * rdev_size_change for 0.90.0
1104  */
1105 static unsigned long long
1106 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1107 {
1108 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1109 		return 0; /* component must fit device */
1110 	if (rdev->mddev->bitmap_offset)
1111 		return 0; /* can't move bitmap */
1112 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1113 	if (!num_sectors || num_sectors > rdev->sb_start)
1114 		num_sectors = rdev->sb_start;
1115 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1116 		       rdev->sb_page);
1117 	md_super_wait(rdev->mddev);
1118 	return num_sectors / 2; /* kB for sysfs */
1119 }
1120 
1121 
1122 /*
1123  * version 1 superblock
1124  */
1125 
1126 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1127 {
1128 	__le32 disk_csum;
1129 	u32 csum;
1130 	unsigned long long newcsum;
1131 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1132 	__le32 *isuper = (__le32*)sb;
1133 	int i;
1134 
1135 	disk_csum = sb->sb_csum;
1136 	sb->sb_csum = 0;
1137 	newcsum = 0;
1138 	for (i=0; size>=4; size -= 4 )
1139 		newcsum += le32_to_cpu(*isuper++);
1140 
1141 	if (size == 2)
1142 		newcsum += le16_to_cpu(*(__le16*) isuper);
1143 
1144 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1145 	sb->sb_csum = disk_csum;
1146 	return cpu_to_le32(csum);
1147 }
1148 
1149 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1150 {
1151 	struct mdp_superblock_1 *sb;
1152 	int ret;
1153 	sector_t sb_start;
1154 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1155 	int bmask;
1156 
1157 	/*
1158 	 * Calculate the position of the superblock in 512byte sectors.
1159 	 * It is always aligned to a 4K boundary and
1160 	 * depeding on minor_version, it can be:
1161 	 * 0: At least 8K, but less than 12K, from end of device
1162 	 * 1: At start of device
1163 	 * 2: 4K from start of device.
1164 	 */
1165 	switch(minor_version) {
1166 	case 0:
1167 		sb_start = rdev->bdev->bd_inode->i_size >> 9;
1168 		sb_start -= 8*2;
1169 		sb_start &= ~(sector_t)(4*2-1);
1170 		break;
1171 	case 1:
1172 		sb_start = 0;
1173 		break;
1174 	case 2:
1175 		sb_start = 8;
1176 		break;
1177 	default:
1178 		return -EINVAL;
1179 	}
1180 	rdev->sb_start = sb_start;
1181 
1182 	/* superblock is rarely larger than 1K, but it can be larger,
1183 	 * and it is safe to read 4k, so we do that
1184 	 */
1185 	ret = read_disk_sb(rdev, 4096);
1186 	if (ret) return ret;
1187 
1188 
1189 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1190 
1191 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1192 	    sb->major_version != cpu_to_le32(1) ||
1193 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1194 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1195 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1196 		return -EINVAL;
1197 
1198 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1199 		printk("md: invalid superblock checksum on %s\n",
1200 			bdevname(rdev->bdev,b));
1201 		return -EINVAL;
1202 	}
1203 	if (le64_to_cpu(sb->data_size) < 10) {
1204 		printk("md: data_size too small on %s\n",
1205 		       bdevname(rdev->bdev,b));
1206 		return -EINVAL;
1207 	}
1208 
1209 	rdev->preferred_minor = 0xffff;
1210 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1211 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1212 
1213 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1214 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1215 	if (rdev->sb_size & bmask)
1216 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1217 
1218 	if (minor_version
1219 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1220 		return -EINVAL;
1221 
1222 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1223 		rdev->desc_nr = -1;
1224 	else
1225 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1226 
1227 	if (!refdev) {
1228 		ret = 1;
1229 	} else {
1230 		__u64 ev1, ev2;
1231 		struct mdp_superblock_1 *refsb =
1232 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1233 
1234 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1235 		    sb->level != refsb->level ||
1236 		    sb->layout != refsb->layout ||
1237 		    sb->chunksize != refsb->chunksize) {
1238 			printk(KERN_WARNING "md: %s has strangely different"
1239 				" superblock to %s\n",
1240 				bdevname(rdev->bdev,b),
1241 				bdevname(refdev->bdev,b2));
1242 			return -EINVAL;
1243 		}
1244 		ev1 = le64_to_cpu(sb->events);
1245 		ev2 = le64_to_cpu(refsb->events);
1246 
1247 		if (ev1 > ev2)
1248 			ret = 1;
1249 		else
1250 			ret = 0;
1251 	}
1252 	if (minor_version)
1253 		rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
1254 			le64_to_cpu(sb->data_offset);
1255 	else
1256 		rdev->sectors = rdev->sb_start;
1257 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1258 		return -EINVAL;
1259 	rdev->sectors = le64_to_cpu(sb->data_size);
1260 	if (le64_to_cpu(sb->size) > rdev->sectors)
1261 		return -EINVAL;
1262 	return ret;
1263 }
1264 
1265 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1266 {
1267 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1268 	__u64 ev1 = le64_to_cpu(sb->events);
1269 
1270 	rdev->raid_disk = -1;
1271 	clear_bit(Faulty, &rdev->flags);
1272 	clear_bit(In_sync, &rdev->flags);
1273 	clear_bit(WriteMostly, &rdev->flags);
1274 	clear_bit(BarriersNotsupp, &rdev->flags);
1275 
1276 	if (mddev->raid_disks == 0) {
1277 		mddev->major_version = 1;
1278 		mddev->patch_version = 0;
1279 		mddev->external = 0;
1280 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1281 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1282 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1283 		mddev->level = le32_to_cpu(sb->level);
1284 		mddev->clevel[0] = 0;
1285 		mddev->layout = le32_to_cpu(sb->layout);
1286 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1287 		mddev->dev_sectors = le64_to_cpu(sb->size);
1288 		mddev->events = ev1;
1289 		mddev->bitmap_offset = 0;
1290 		mddev->default_bitmap_offset = 1024 >> 9;
1291 
1292 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1293 		memcpy(mddev->uuid, sb->set_uuid, 16);
1294 
1295 		mddev->max_disks =  (4096-256)/2;
1296 
1297 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1298 		    mddev->bitmap_file == NULL )
1299 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1300 
1301 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1302 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1303 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1304 			mddev->new_level = le32_to_cpu(sb->new_level);
1305 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1306 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1307 		} else {
1308 			mddev->reshape_position = MaxSector;
1309 			mddev->delta_disks = 0;
1310 			mddev->new_level = mddev->level;
1311 			mddev->new_layout = mddev->layout;
1312 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1313 		}
1314 
1315 	} else if (mddev->pers == NULL) {
1316 		/* Insist of good event counter while assembling */
1317 		++ev1;
1318 		if (ev1 < mddev->events)
1319 			return -EINVAL;
1320 	} else if (mddev->bitmap) {
1321 		/* If adding to array with a bitmap, then we can accept an
1322 		 * older device, but not too old.
1323 		 */
1324 		if (ev1 < mddev->bitmap->events_cleared)
1325 			return 0;
1326 	} else {
1327 		if (ev1 < mddev->events)
1328 			/* just a hot-add of a new device, leave raid_disk at -1 */
1329 			return 0;
1330 	}
1331 	if (mddev->level != LEVEL_MULTIPATH) {
1332 		int role;
1333 		if (rdev->desc_nr < 0 ||
1334 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1335 			role = 0xffff;
1336 			rdev->desc_nr = -1;
1337 		} else
1338 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1339 		switch(role) {
1340 		case 0xffff: /* spare */
1341 			break;
1342 		case 0xfffe: /* faulty */
1343 			set_bit(Faulty, &rdev->flags);
1344 			break;
1345 		default:
1346 			if ((le32_to_cpu(sb->feature_map) &
1347 			     MD_FEATURE_RECOVERY_OFFSET))
1348 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1349 			else
1350 				set_bit(In_sync, &rdev->flags);
1351 			rdev->raid_disk = role;
1352 			break;
1353 		}
1354 		if (sb->devflags & WriteMostly1)
1355 			set_bit(WriteMostly, &rdev->flags);
1356 	} else /* MULTIPATH are always insync */
1357 		set_bit(In_sync, &rdev->flags);
1358 
1359 	return 0;
1360 }
1361 
1362 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1363 {
1364 	struct mdp_superblock_1 *sb;
1365 	mdk_rdev_t *rdev2;
1366 	int max_dev, i;
1367 	/* make rdev->sb match mddev and rdev data. */
1368 
1369 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1370 
1371 	sb->feature_map = 0;
1372 	sb->pad0 = 0;
1373 	sb->recovery_offset = cpu_to_le64(0);
1374 	memset(sb->pad1, 0, sizeof(sb->pad1));
1375 	memset(sb->pad2, 0, sizeof(sb->pad2));
1376 	memset(sb->pad3, 0, sizeof(sb->pad3));
1377 
1378 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1379 	sb->events = cpu_to_le64(mddev->events);
1380 	if (mddev->in_sync)
1381 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1382 	else
1383 		sb->resync_offset = cpu_to_le64(0);
1384 
1385 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1386 
1387 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1388 	sb->size = cpu_to_le64(mddev->dev_sectors);
1389 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1390 	sb->level = cpu_to_le32(mddev->level);
1391 	sb->layout = cpu_to_le32(mddev->layout);
1392 
1393 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1394 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1395 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1396 	}
1397 
1398 	if (rdev->raid_disk >= 0 &&
1399 	    !test_bit(In_sync, &rdev->flags)) {
1400 		if (rdev->recovery_offset > 0) {
1401 			sb->feature_map |=
1402 				cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1403 			sb->recovery_offset =
1404 				cpu_to_le64(rdev->recovery_offset);
1405 		}
1406 	}
1407 
1408 	if (mddev->reshape_position != MaxSector) {
1409 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1410 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1411 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1412 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1413 		sb->new_level = cpu_to_le32(mddev->new_level);
1414 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1415 	}
1416 
1417 	max_dev = 0;
1418 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1419 		if (rdev2->desc_nr+1 > max_dev)
1420 			max_dev = rdev2->desc_nr+1;
1421 
1422 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1423 		int bmask;
1424 		sb->max_dev = cpu_to_le32(max_dev);
1425 		rdev->sb_size = max_dev * 2 + 256;
1426 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1427 		if (rdev->sb_size & bmask)
1428 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1429 	}
1430 	for (i=0; i<max_dev;i++)
1431 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1432 
1433 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1434 		i = rdev2->desc_nr;
1435 		if (test_bit(Faulty, &rdev2->flags))
1436 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1437 		else if (test_bit(In_sync, &rdev2->flags))
1438 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1439 		else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
1440 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1441 		else
1442 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1443 	}
1444 
1445 	sb->sb_csum = calc_sb_1_csum(sb);
1446 }
1447 
1448 static unsigned long long
1449 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1450 {
1451 	struct mdp_superblock_1 *sb;
1452 	sector_t max_sectors;
1453 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1454 		return 0; /* component must fit device */
1455 	if (rdev->sb_start < rdev->data_offset) {
1456 		/* minor versions 1 and 2; superblock before data */
1457 		max_sectors = rdev->bdev->bd_inode->i_size >> 9;
1458 		max_sectors -= rdev->data_offset;
1459 		if (!num_sectors || num_sectors > max_sectors)
1460 			num_sectors = max_sectors;
1461 	} else if (rdev->mddev->bitmap_offset) {
1462 		/* minor version 0 with bitmap we can't move */
1463 		return 0;
1464 	} else {
1465 		/* minor version 0; superblock after data */
1466 		sector_t sb_start;
1467 		sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
1468 		sb_start &= ~(sector_t)(4*2 - 1);
1469 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1470 		if (!num_sectors || num_sectors > max_sectors)
1471 			num_sectors = max_sectors;
1472 		rdev->sb_start = sb_start;
1473 	}
1474 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1475 	sb->data_size = cpu_to_le64(num_sectors);
1476 	sb->super_offset = rdev->sb_start;
1477 	sb->sb_csum = calc_sb_1_csum(sb);
1478 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1479 		       rdev->sb_page);
1480 	md_super_wait(rdev->mddev);
1481 	return num_sectors / 2; /* kB for sysfs */
1482 }
1483 
1484 static struct super_type super_types[] = {
1485 	[0] = {
1486 		.name	= "0.90.0",
1487 		.owner	= THIS_MODULE,
1488 		.load_super	    = super_90_load,
1489 		.validate_super	    = super_90_validate,
1490 		.sync_super	    = super_90_sync,
1491 		.rdev_size_change   = super_90_rdev_size_change,
1492 	},
1493 	[1] = {
1494 		.name	= "md-1",
1495 		.owner	= THIS_MODULE,
1496 		.load_super	    = super_1_load,
1497 		.validate_super	    = super_1_validate,
1498 		.sync_super	    = super_1_sync,
1499 		.rdev_size_change   = super_1_rdev_size_change,
1500 	},
1501 };
1502 
1503 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1504 {
1505 	mdk_rdev_t *rdev, *rdev2;
1506 
1507 	rcu_read_lock();
1508 	rdev_for_each_rcu(rdev, mddev1)
1509 		rdev_for_each_rcu(rdev2, mddev2)
1510 			if (rdev->bdev->bd_contains ==
1511 			    rdev2->bdev->bd_contains) {
1512 				rcu_read_unlock();
1513 				return 1;
1514 			}
1515 	rcu_read_unlock();
1516 	return 0;
1517 }
1518 
1519 static LIST_HEAD(pending_raid_disks);
1520 
1521 /*
1522  * Try to register data integrity profile for an mddev
1523  *
1524  * This is called when an array is started and after a disk has been kicked
1525  * from the array. It only succeeds if all working and active component devices
1526  * are integrity capable with matching profiles.
1527  */
1528 int md_integrity_register(mddev_t *mddev)
1529 {
1530 	mdk_rdev_t *rdev, *reference = NULL;
1531 
1532 	if (list_empty(&mddev->disks))
1533 		return 0; /* nothing to do */
1534 	if (blk_get_integrity(mddev->gendisk))
1535 		return 0; /* already registered */
1536 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1537 		/* skip spares and non-functional disks */
1538 		if (test_bit(Faulty, &rdev->flags))
1539 			continue;
1540 		if (rdev->raid_disk < 0)
1541 			continue;
1542 		/*
1543 		 * If at least one rdev is not integrity capable, we can not
1544 		 * enable data integrity for the md device.
1545 		 */
1546 		if (!bdev_get_integrity(rdev->bdev))
1547 			return -EINVAL;
1548 		if (!reference) {
1549 			/* Use the first rdev as the reference */
1550 			reference = rdev;
1551 			continue;
1552 		}
1553 		/* does this rdev's profile match the reference profile? */
1554 		if (blk_integrity_compare(reference->bdev->bd_disk,
1555 				rdev->bdev->bd_disk) < 0)
1556 			return -EINVAL;
1557 	}
1558 	/*
1559 	 * All component devices are integrity capable and have matching
1560 	 * profiles, register the common profile for the md device.
1561 	 */
1562 	if (blk_integrity_register(mddev->gendisk,
1563 			bdev_get_integrity(reference->bdev)) != 0) {
1564 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1565 			mdname(mddev));
1566 		return -EINVAL;
1567 	}
1568 	printk(KERN_NOTICE "md: data integrity on %s enabled\n",
1569 		mdname(mddev));
1570 	return 0;
1571 }
1572 EXPORT_SYMBOL(md_integrity_register);
1573 
1574 /* Disable data integrity if non-capable/non-matching disk is being added */
1575 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1576 {
1577 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1578 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1579 
1580 	if (!bi_mddev) /* nothing to do */
1581 		return;
1582 	if (rdev->raid_disk < 0) /* skip spares */
1583 		return;
1584 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1585 					     rdev->bdev->bd_disk) >= 0)
1586 		return;
1587 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1588 	blk_integrity_unregister(mddev->gendisk);
1589 }
1590 EXPORT_SYMBOL(md_integrity_add_rdev);
1591 
1592 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1593 {
1594 	char b[BDEVNAME_SIZE];
1595 	struct kobject *ko;
1596 	char *s;
1597 	int err;
1598 
1599 	if (rdev->mddev) {
1600 		MD_BUG();
1601 		return -EINVAL;
1602 	}
1603 
1604 	/* prevent duplicates */
1605 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1606 		return -EEXIST;
1607 
1608 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
1609 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
1610 			rdev->sectors < mddev->dev_sectors)) {
1611 		if (mddev->pers) {
1612 			/* Cannot change size, so fail
1613 			 * If mddev->level <= 0, then we don't care
1614 			 * about aligning sizes (e.g. linear)
1615 			 */
1616 			if (mddev->level > 0)
1617 				return -ENOSPC;
1618 		} else
1619 			mddev->dev_sectors = rdev->sectors;
1620 	}
1621 
1622 	/* Verify rdev->desc_nr is unique.
1623 	 * If it is -1, assign a free number, else
1624 	 * check number is not in use
1625 	 */
1626 	if (rdev->desc_nr < 0) {
1627 		int choice = 0;
1628 		if (mddev->pers) choice = mddev->raid_disks;
1629 		while (find_rdev_nr(mddev, choice))
1630 			choice++;
1631 		rdev->desc_nr = choice;
1632 	} else {
1633 		if (find_rdev_nr(mddev, rdev->desc_nr))
1634 			return -EBUSY;
1635 	}
1636 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1637 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1638 		       mdname(mddev), mddev->max_disks);
1639 		return -EBUSY;
1640 	}
1641 	bdevname(rdev->bdev,b);
1642 	while ( (s=strchr(b, '/')) != NULL)
1643 		*s = '!';
1644 
1645 	rdev->mddev = mddev;
1646 	printk(KERN_INFO "md: bind<%s>\n", b);
1647 
1648 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1649 		goto fail;
1650 
1651 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1652 	if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
1653 		kobject_del(&rdev->kobj);
1654 		goto fail;
1655 	}
1656 	rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, "state");
1657 
1658 	list_add_rcu(&rdev->same_set, &mddev->disks);
1659 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1660 
1661 	/* May as well allow recovery to be retried once */
1662 	mddev->recovery_disabled = 0;
1663 
1664 	return 0;
1665 
1666  fail:
1667 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1668 	       b, mdname(mddev));
1669 	return err;
1670 }
1671 
1672 static void md_delayed_delete(struct work_struct *ws)
1673 {
1674 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1675 	kobject_del(&rdev->kobj);
1676 	kobject_put(&rdev->kobj);
1677 }
1678 
1679 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1680 {
1681 	char b[BDEVNAME_SIZE];
1682 	if (!rdev->mddev) {
1683 		MD_BUG();
1684 		return;
1685 	}
1686 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1687 	list_del_rcu(&rdev->same_set);
1688 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1689 	rdev->mddev = NULL;
1690 	sysfs_remove_link(&rdev->kobj, "block");
1691 	sysfs_put(rdev->sysfs_state);
1692 	rdev->sysfs_state = NULL;
1693 	/* We need to delay this, otherwise we can deadlock when
1694 	 * writing to 'remove' to "dev/state".  We also need
1695 	 * to delay it due to rcu usage.
1696 	 */
1697 	synchronize_rcu();
1698 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1699 	kobject_get(&rdev->kobj);
1700 	schedule_work(&rdev->del_work);
1701 }
1702 
1703 /*
1704  * prevent the device from being mounted, repartitioned or
1705  * otherwise reused by a RAID array (or any other kernel
1706  * subsystem), by bd_claiming the device.
1707  */
1708 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1709 {
1710 	int err = 0;
1711 	struct block_device *bdev;
1712 	char b[BDEVNAME_SIZE];
1713 
1714 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1715 	if (IS_ERR(bdev)) {
1716 		printk(KERN_ERR "md: could not open %s.\n",
1717 			__bdevname(dev, b));
1718 		return PTR_ERR(bdev);
1719 	}
1720 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1721 	if (err) {
1722 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1723 			bdevname(bdev, b));
1724 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1725 		return err;
1726 	}
1727 	if (!shared)
1728 		set_bit(AllReserved, &rdev->flags);
1729 	rdev->bdev = bdev;
1730 	return err;
1731 }
1732 
1733 static void unlock_rdev(mdk_rdev_t *rdev)
1734 {
1735 	struct block_device *bdev = rdev->bdev;
1736 	rdev->bdev = NULL;
1737 	if (!bdev)
1738 		MD_BUG();
1739 	bd_release(bdev);
1740 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1741 }
1742 
1743 void md_autodetect_dev(dev_t dev);
1744 
1745 static void export_rdev(mdk_rdev_t * rdev)
1746 {
1747 	char b[BDEVNAME_SIZE];
1748 	printk(KERN_INFO "md: export_rdev(%s)\n",
1749 		bdevname(rdev->bdev,b));
1750 	if (rdev->mddev)
1751 		MD_BUG();
1752 	free_disk_sb(rdev);
1753 #ifndef MODULE
1754 	if (test_bit(AutoDetected, &rdev->flags))
1755 		md_autodetect_dev(rdev->bdev->bd_dev);
1756 #endif
1757 	unlock_rdev(rdev);
1758 	kobject_put(&rdev->kobj);
1759 }
1760 
1761 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1762 {
1763 	unbind_rdev_from_array(rdev);
1764 	export_rdev(rdev);
1765 }
1766 
1767 static void export_array(mddev_t *mddev)
1768 {
1769 	mdk_rdev_t *rdev, *tmp;
1770 
1771 	rdev_for_each(rdev, tmp, mddev) {
1772 		if (!rdev->mddev) {
1773 			MD_BUG();
1774 			continue;
1775 		}
1776 		kick_rdev_from_array(rdev);
1777 	}
1778 	if (!list_empty(&mddev->disks))
1779 		MD_BUG();
1780 	mddev->raid_disks = 0;
1781 	mddev->major_version = 0;
1782 }
1783 
1784 static void print_desc(mdp_disk_t *desc)
1785 {
1786 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1787 		desc->major,desc->minor,desc->raid_disk,desc->state);
1788 }
1789 
1790 static void print_sb_90(mdp_super_t *sb)
1791 {
1792 	int i;
1793 
1794 	printk(KERN_INFO
1795 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1796 		sb->major_version, sb->minor_version, sb->patch_version,
1797 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1798 		sb->ctime);
1799 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1800 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1801 		sb->md_minor, sb->layout, sb->chunk_size);
1802 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1803 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1804 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1805 		sb->failed_disks, sb->spare_disks,
1806 		sb->sb_csum, (unsigned long)sb->events_lo);
1807 
1808 	printk(KERN_INFO);
1809 	for (i = 0; i < MD_SB_DISKS; i++) {
1810 		mdp_disk_t *desc;
1811 
1812 		desc = sb->disks + i;
1813 		if (desc->number || desc->major || desc->minor ||
1814 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1815 			printk("     D %2d: ", i);
1816 			print_desc(desc);
1817 		}
1818 	}
1819 	printk(KERN_INFO "md:     THIS: ");
1820 	print_desc(&sb->this_disk);
1821 }
1822 
1823 static void print_sb_1(struct mdp_superblock_1 *sb)
1824 {
1825 	__u8 *uuid;
1826 
1827 	uuid = sb->set_uuid;
1828 	printk(KERN_INFO
1829 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%02x%02x%02x%02x"
1830 	       ":%02x%02x:%02x%02x:%02x%02x:%02x%02x%02x%02x%02x%02x>\n"
1831 	       "md:    Name: \"%s\" CT:%llu\n",
1832 		le32_to_cpu(sb->major_version),
1833 		le32_to_cpu(sb->feature_map),
1834 		uuid[0], uuid[1], uuid[2], uuid[3],
1835 		uuid[4], uuid[5], uuid[6], uuid[7],
1836 		uuid[8], uuid[9], uuid[10], uuid[11],
1837 		uuid[12], uuid[13], uuid[14], uuid[15],
1838 		sb->set_name,
1839 		(unsigned long long)le64_to_cpu(sb->ctime)
1840 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
1841 
1842 	uuid = sb->device_uuid;
1843 	printk(KERN_INFO
1844 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
1845 			" RO:%llu\n"
1846 	       "md:     Dev:%08x UUID: %02x%02x%02x%02x:%02x%02x:%02x%02x:%02x%02x"
1847 	                ":%02x%02x%02x%02x%02x%02x\n"
1848 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
1849 	       "md:         (MaxDev:%u) \n",
1850 		le32_to_cpu(sb->level),
1851 		(unsigned long long)le64_to_cpu(sb->size),
1852 		le32_to_cpu(sb->raid_disks),
1853 		le32_to_cpu(sb->layout),
1854 		le32_to_cpu(sb->chunksize),
1855 		(unsigned long long)le64_to_cpu(sb->data_offset),
1856 		(unsigned long long)le64_to_cpu(sb->data_size),
1857 		(unsigned long long)le64_to_cpu(sb->super_offset),
1858 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
1859 		le32_to_cpu(sb->dev_number),
1860 		uuid[0], uuid[1], uuid[2], uuid[3],
1861 		uuid[4], uuid[5], uuid[6], uuid[7],
1862 		uuid[8], uuid[9], uuid[10], uuid[11],
1863 		uuid[12], uuid[13], uuid[14], uuid[15],
1864 		sb->devflags,
1865 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
1866 		(unsigned long long)le64_to_cpu(sb->events),
1867 		(unsigned long long)le64_to_cpu(sb->resync_offset),
1868 		le32_to_cpu(sb->sb_csum),
1869 		le32_to_cpu(sb->max_dev)
1870 		);
1871 }
1872 
1873 static void print_rdev(mdk_rdev_t *rdev, int major_version)
1874 {
1875 	char b[BDEVNAME_SIZE];
1876 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
1877 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
1878 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1879 	        rdev->desc_nr);
1880 	if (rdev->sb_loaded) {
1881 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
1882 		switch (major_version) {
1883 		case 0:
1884 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
1885 			break;
1886 		case 1:
1887 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
1888 			break;
1889 		}
1890 	} else
1891 		printk(KERN_INFO "md: no rdev superblock!\n");
1892 }
1893 
1894 static void md_print_devices(void)
1895 {
1896 	struct list_head *tmp;
1897 	mdk_rdev_t *rdev;
1898 	mddev_t *mddev;
1899 	char b[BDEVNAME_SIZE];
1900 
1901 	printk("\n");
1902 	printk("md:	**********************************\n");
1903 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1904 	printk("md:	**********************************\n");
1905 	for_each_mddev(mddev, tmp) {
1906 
1907 		if (mddev->bitmap)
1908 			bitmap_print_sb(mddev->bitmap);
1909 		else
1910 			printk("%s: ", mdname(mddev));
1911 		list_for_each_entry(rdev, &mddev->disks, same_set)
1912 			printk("<%s>", bdevname(rdev->bdev,b));
1913 		printk("\n");
1914 
1915 		list_for_each_entry(rdev, &mddev->disks, same_set)
1916 			print_rdev(rdev, mddev->major_version);
1917 	}
1918 	printk("md:	**********************************\n");
1919 	printk("\n");
1920 }
1921 
1922 
1923 static void sync_sbs(mddev_t * mddev, int nospares)
1924 {
1925 	/* Update each superblock (in-memory image), but
1926 	 * if we are allowed to, skip spares which already
1927 	 * have the right event counter, or have one earlier
1928 	 * (which would mean they aren't being marked as dirty
1929 	 * with the rest of the array)
1930 	 */
1931 	mdk_rdev_t *rdev;
1932 
1933 	/* First make sure individual recovery_offsets are correct */
1934 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1935 		if (rdev->raid_disk >= 0 &&
1936 		    !test_bit(In_sync, &rdev->flags) &&
1937 		    mddev->curr_resync_completed > rdev->recovery_offset)
1938 				rdev->recovery_offset = mddev->curr_resync_completed;
1939 
1940 	}
1941 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1942 		if (rdev->sb_events == mddev->events ||
1943 		    (nospares &&
1944 		     rdev->raid_disk < 0 &&
1945 		     (rdev->sb_events&1)==0 &&
1946 		     rdev->sb_events+1 == mddev->events)) {
1947 			/* Don't update this superblock */
1948 			rdev->sb_loaded = 2;
1949 		} else {
1950 			super_types[mddev->major_version].
1951 				sync_super(mddev, rdev);
1952 			rdev->sb_loaded = 1;
1953 		}
1954 	}
1955 }
1956 
1957 static void md_update_sb(mddev_t * mddev, int force_change)
1958 {
1959 	mdk_rdev_t *rdev;
1960 	int sync_req;
1961 	int nospares = 0;
1962 
1963 	mddev->utime = get_seconds();
1964 	if (mddev->external)
1965 		return;
1966 repeat:
1967 	spin_lock_irq(&mddev->write_lock);
1968 
1969 	set_bit(MD_CHANGE_PENDING, &mddev->flags);
1970 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
1971 		force_change = 1;
1972 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
1973 		/* just a clean<-> dirty transition, possibly leave spares alone,
1974 		 * though if events isn't the right even/odd, we will have to do
1975 		 * spares after all
1976 		 */
1977 		nospares = 1;
1978 	if (force_change)
1979 		nospares = 0;
1980 	if (mddev->degraded)
1981 		/* If the array is degraded, then skipping spares is both
1982 		 * dangerous and fairly pointless.
1983 		 * Dangerous because a device that was removed from the array
1984 		 * might have a event_count that still looks up-to-date,
1985 		 * so it can be re-added without a resync.
1986 		 * Pointless because if there are any spares to skip,
1987 		 * then a recovery will happen and soon that array won't
1988 		 * be degraded any more and the spare can go back to sleep then.
1989 		 */
1990 		nospares = 0;
1991 
1992 	sync_req = mddev->in_sync;
1993 
1994 	/* If this is just a dirty<->clean transition, and the array is clean
1995 	 * and 'events' is odd, we can roll back to the previous clean state */
1996 	if (nospares
1997 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
1998 	    && (mddev->events & 1)
1999 	    && mddev->events != 1)
2000 		mddev->events--;
2001 	else {
2002 		/* otherwise we have to go forward and ... */
2003 		mddev->events ++;
2004 		if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
2005 			/* .. if the array isn't clean, an 'even' event must also go
2006 			 * to spares. */
2007 			if ((mddev->events&1)==0)
2008 				nospares = 0;
2009 		} else {
2010 			/* otherwise an 'odd' event must go to spares */
2011 			if ((mddev->events&1))
2012 				nospares = 0;
2013 		}
2014 	}
2015 
2016 	if (!mddev->events) {
2017 		/*
2018 		 * oops, this 64-bit counter should never wrap.
2019 		 * Either we are in around ~1 trillion A.C., assuming
2020 		 * 1 reboot per second, or we have a bug:
2021 		 */
2022 		MD_BUG();
2023 		mddev->events --;
2024 	}
2025 
2026 	/*
2027 	 * do not write anything to disk if using
2028 	 * nonpersistent superblocks
2029 	 */
2030 	if (!mddev->persistent) {
2031 		if (!mddev->external)
2032 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2033 
2034 		spin_unlock_irq(&mddev->write_lock);
2035 		wake_up(&mddev->sb_wait);
2036 		return;
2037 	}
2038 	sync_sbs(mddev, nospares);
2039 	spin_unlock_irq(&mddev->write_lock);
2040 
2041 	dprintk(KERN_INFO
2042 		"md: updating %s RAID superblock on device (in sync %d)\n",
2043 		mdname(mddev),mddev->in_sync);
2044 
2045 	bitmap_update_sb(mddev->bitmap);
2046 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2047 		char b[BDEVNAME_SIZE];
2048 		dprintk(KERN_INFO "md: ");
2049 		if (rdev->sb_loaded != 1)
2050 			continue; /* no noise on spare devices */
2051 		if (test_bit(Faulty, &rdev->flags))
2052 			dprintk("(skipping faulty ");
2053 
2054 		dprintk("%s ", bdevname(rdev->bdev,b));
2055 		if (!test_bit(Faulty, &rdev->flags)) {
2056 			md_super_write(mddev,rdev,
2057 				       rdev->sb_start, rdev->sb_size,
2058 				       rdev->sb_page);
2059 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2060 				bdevname(rdev->bdev,b),
2061 				(unsigned long long)rdev->sb_start);
2062 			rdev->sb_events = mddev->events;
2063 
2064 		} else
2065 			dprintk(")\n");
2066 		if (mddev->level == LEVEL_MULTIPATH)
2067 			/* only need to write one superblock... */
2068 			break;
2069 	}
2070 	md_super_wait(mddev);
2071 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2072 
2073 	spin_lock_irq(&mddev->write_lock);
2074 	if (mddev->in_sync != sync_req ||
2075 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2076 		/* have to write it out again */
2077 		spin_unlock_irq(&mddev->write_lock);
2078 		goto repeat;
2079 	}
2080 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2081 	spin_unlock_irq(&mddev->write_lock);
2082 	wake_up(&mddev->sb_wait);
2083 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2084 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2085 
2086 }
2087 
2088 /* words written to sysfs files may, or may not, be \n terminated.
2089  * We want to accept with case. For this we use cmd_match.
2090  */
2091 static int cmd_match(const char *cmd, const char *str)
2092 {
2093 	/* See if cmd, written into a sysfs file, matches
2094 	 * str.  They must either be the same, or cmd can
2095 	 * have a trailing newline
2096 	 */
2097 	while (*cmd && *str && *cmd == *str) {
2098 		cmd++;
2099 		str++;
2100 	}
2101 	if (*cmd == '\n')
2102 		cmd++;
2103 	if (*str || *cmd)
2104 		return 0;
2105 	return 1;
2106 }
2107 
2108 struct rdev_sysfs_entry {
2109 	struct attribute attr;
2110 	ssize_t (*show)(mdk_rdev_t *, char *);
2111 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2112 };
2113 
2114 static ssize_t
2115 state_show(mdk_rdev_t *rdev, char *page)
2116 {
2117 	char *sep = "";
2118 	size_t len = 0;
2119 
2120 	if (test_bit(Faulty, &rdev->flags)) {
2121 		len+= sprintf(page+len, "%sfaulty",sep);
2122 		sep = ",";
2123 	}
2124 	if (test_bit(In_sync, &rdev->flags)) {
2125 		len += sprintf(page+len, "%sin_sync",sep);
2126 		sep = ",";
2127 	}
2128 	if (test_bit(WriteMostly, &rdev->flags)) {
2129 		len += sprintf(page+len, "%swrite_mostly",sep);
2130 		sep = ",";
2131 	}
2132 	if (test_bit(Blocked, &rdev->flags)) {
2133 		len += sprintf(page+len, "%sblocked", sep);
2134 		sep = ",";
2135 	}
2136 	if (!test_bit(Faulty, &rdev->flags) &&
2137 	    !test_bit(In_sync, &rdev->flags)) {
2138 		len += sprintf(page+len, "%sspare", sep);
2139 		sep = ",";
2140 	}
2141 	return len+sprintf(page+len, "\n");
2142 }
2143 
2144 static ssize_t
2145 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2146 {
2147 	/* can write
2148 	 *  faulty  - simulates and error
2149 	 *  remove  - disconnects the device
2150 	 *  writemostly - sets write_mostly
2151 	 *  -writemostly - clears write_mostly
2152 	 *  blocked - sets the Blocked flag
2153 	 *  -blocked - clears the Blocked flag
2154 	 *  insync - sets Insync providing device isn't active
2155 	 */
2156 	int err = -EINVAL;
2157 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2158 		md_error(rdev->mddev, rdev);
2159 		err = 0;
2160 	} else if (cmd_match(buf, "remove")) {
2161 		if (rdev->raid_disk >= 0)
2162 			err = -EBUSY;
2163 		else {
2164 			mddev_t *mddev = rdev->mddev;
2165 			kick_rdev_from_array(rdev);
2166 			if (mddev->pers)
2167 				md_update_sb(mddev, 1);
2168 			md_new_event(mddev);
2169 			err = 0;
2170 		}
2171 	} else if (cmd_match(buf, "writemostly")) {
2172 		set_bit(WriteMostly, &rdev->flags);
2173 		err = 0;
2174 	} else if (cmd_match(buf, "-writemostly")) {
2175 		clear_bit(WriteMostly, &rdev->flags);
2176 		err = 0;
2177 	} else if (cmd_match(buf, "blocked")) {
2178 		set_bit(Blocked, &rdev->flags);
2179 		err = 0;
2180 	} else if (cmd_match(buf, "-blocked")) {
2181 		clear_bit(Blocked, &rdev->flags);
2182 		wake_up(&rdev->blocked_wait);
2183 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2184 		md_wakeup_thread(rdev->mddev->thread);
2185 
2186 		err = 0;
2187 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2188 		set_bit(In_sync, &rdev->flags);
2189 		err = 0;
2190 	}
2191 	if (!err && rdev->sysfs_state)
2192 		sysfs_notify_dirent(rdev->sysfs_state);
2193 	return err ? err : len;
2194 }
2195 static struct rdev_sysfs_entry rdev_state =
2196 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2197 
2198 static ssize_t
2199 errors_show(mdk_rdev_t *rdev, char *page)
2200 {
2201 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2202 }
2203 
2204 static ssize_t
2205 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2206 {
2207 	char *e;
2208 	unsigned long n = simple_strtoul(buf, &e, 10);
2209 	if (*buf && (*e == 0 || *e == '\n')) {
2210 		atomic_set(&rdev->corrected_errors, n);
2211 		return len;
2212 	}
2213 	return -EINVAL;
2214 }
2215 static struct rdev_sysfs_entry rdev_errors =
2216 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2217 
2218 static ssize_t
2219 slot_show(mdk_rdev_t *rdev, char *page)
2220 {
2221 	if (rdev->raid_disk < 0)
2222 		return sprintf(page, "none\n");
2223 	else
2224 		return sprintf(page, "%d\n", rdev->raid_disk);
2225 }
2226 
2227 static ssize_t
2228 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2229 {
2230 	char *e;
2231 	int err;
2232 	char nm[20];
2233 	int slot = simple_strtoul(buf, &e, 10);
2234 	if (strncmp(buf, "none", 4)==0)
2235 		slot = -1;
2236 	else if (e==buf || (*e && *e!= '\n'))
2237 		return -EINVAL;
2238 	if (rdev->mddev->pers && slot == -1) {
2239 		/* Setting 'slot' on an active array requires also
2240 		 * updating the 'rd%d' link, and communicating
2241 		 * with the personality with ->hot_*_disk.
2242 		 * For now we only support removing
2243 		 * failed/spare devices.  This normally happens automatically,
2244 		 * but not when the metadata is externally managed.
2245 		 */
2246 		if (rdev->raid_disk == -1)
2247 			return -EEXIST;
2248 		/* personality does all needed checks */
2249 		if (rdev->mddev->pers->hot_add_disk == NULL)
2250 			return -EINVAL;
2251 		err = rdev->mddev->pers->
2252 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2253 		if (err)
2254 			return err;
2255 		sprintf(nm, "rd%d", rdev->raid_disk);
2256 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2257 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2258 		md_wakeup_thread(rdev->mddev->thread);
2259 	} else if (rdev->mddev->pers) {
2260 		mdk_rdev_t *rdev2;
2261 		/* Activating a spare .. or possibly reactivating
2262 		 * if we ever get bitmaps working here.
2263 		 */
2264 
2265 		if (rdev->raid_disk != -1)
2266 			return -EBUSY;
2267 
2268 		if (rdev->mddev->pers->hot_add_disk == NULL)
2269 			return -EINVAL;
2270 
2271 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2272 			if (rdev2->raid_disk == slot)
2273 				return -EEXIST;
2274 
2275 		rdev->raid_disk = slot;
2276 		if (test_bit(In_sync, &rdev->flags))
2277 			rdev->saved_raid_disk = slot;
2278 		else
2279 			rdev->saved_raid_disk = -1;
2280 		err = rdev->mddev->pers->
2281 			hot_add_disk(rdev->mddev, rdev);
2282 		if (err) {
2283 			rdev->raid_disk = -1;
2284 			return err;
2285 		} else
2286 			sysfs_notify_dirent(rdev->sysfs_state);
2287 		sprintf(nm, "rd%d", rdev->raid_disk);
2288 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2289 			printk(KERN_WARNING
2290 			       "md: cannot register "
2291 			       "%s for %s\n",
2292 			       nm, mdname(rdev->mddev));
2293 
2294 		/* don't wakeup anyone, leave that to userspace. */
2295 	} else {
2296 		if (slot >= rdev->mddev->raid_disks)
2297 			return -ENOSPC;
2298 		rdev->raid_disk = slot;
2299 		/* assume it is working */
2300 		clear_bit(Faulty, &rdev->flags);
2301 		clear_bit(WriteMostly, &rdev->flags);
2302 		set_bit(In_sync, &rdev->flags);
2303 		sysfs_notify_dirent(rdev->sysfs_state);
2304 	}
2305 	return len;
2306 }
2307 
2308 
2309 static struct rdev_sysfs_entry rdev_slot =
2310 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2311 
2312 static ssize_t
2313 offset_show(mdk_rdev_t *rdev, char *page)
2314 {
2315 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2316 }
2317 
2318 static ssize_t
2319 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2320 {
2321 	char *e;
2322 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2323 	if (e==buf || (*e && *e != '\n'))
2324 		return -EINVAL;
2325 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2326 		return -EBUSY;
2327 	if (rdev->sectors && rdev->mddev->external)
2328 		/* Must set offset before size, so overlap checks
2329 		 * can be sane */
2330 		return -EBUSY;
2331 	rdev->data_offset = offset;
2332 	return len;
2333 }
2334 
2335 static struct rdev_sysfs_entry rdev_offset =
2336 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2337 
2338 static ssize_t
2339 rdev_size_show(mdk_rdev_t *rdev, char *page)
2340 {
2341 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2342 }
2343 
2344 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2345 {
2346 	/* check if two start/length pairs overlap */
2347 	if (s1+l1 <= s2)
2348 		return 0;
2349 	if (s2+l2 <= s1)
2350 		return 0;
2351 	return 1;
2352 }
2353 
2354 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2355 {
2356 	unsigned long long blocks;
2357 	sector_t new;
2358 
2359 	if (strict_strtoull(buf, 10, &blocks) < 0)
2360 		return -EINVAL;
2361 
2362 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2363 		return -EINVAL; /* sector conversion overflow */
2364 
2365 	new = blocks * 2;
2366 	if (new != blocks * 2)
2367 		return -EINVAL; /* unsigned long long to sector_t overflow */
2368 
2369 	*sectors = new;
2370 	return 0;
2371 }
2372 
2373 static ssize_t
2374 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2375 {
2376 	mddev_t *my_mddev = rdev->mddev;
2377 	sector_t oldsectors = rdev->sectors;
2378 	sector_t sectors;
2379 
2380 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2381 		return -EINVAL;
2382 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2383 		if (my_mddev->persistent) {
2384 			sectors = super_types[my_mddev->major_version].
2385 				rdev_size_change(rdev, sectors);
2386 			if (!sectors)
2387 				return -EBUSY;
2388 		} else if (!sectors)
2389 			sectors = (rdev->bdev->bd_inode->i_size >> 9) -
2390 				rdev->data_offset;
2391 	}
2392 	if (sectors < my_mddev->dev_sectors)
2393 		return -EINVAL; /* component must fit device */
2394 
2395 	rdev->sectors = sectors;
2396 	if (sectors > oldsectors && my_mddev->external) {
2397 		/* need to check that all other rdevs with the same ->bdev
2398 		 * do not overlap.  We need to unlock the mddev to avoid
2399 		 * a deadlock.  We have already changed rdev->sectors, and if
2400 		 * we have to change it back, we will have the lock again.
2401 		 */
2402 		mddev_t *mddev;
2403 		int overlap = 0;
2404 		struct list_head *tmp;
2405 
2406 		mddev_unlock(my_mddev);
2407 		for_each_mddev(mddev, tmp) {
2408 			mdk_rdev_t *rdev2;
2409 
2410 			mddev_lock(mddev);
2411 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2412 				if (test_bit(AllReserved, &rdev2->flags) ||
2413 				    (rdev->bdev == rdev2->bdev &&
2414 				     rdev != rdev2 &&
2415 				     overlaps(rdev->data_offset, rdev->sectors,
2416 					      rdev2->data_offset,
2417 					      rdev2->sectors))) {
2418 					overlap = 1;
2419 					break;
2420 				}
2421 			mddev_unlock(mddev);
2422 			if (overlap) {
2423 				mddev_put(mddev);
2424 				break;
2425 			}
2426 		}
2427 		mddev_lock(my_mddev);
2428 		if (overlap) {
2429 			/* Someone else could have slipped in a size
2430 			 * change here, but doing so is just silly.
2431 			 * We put oldsectors back because we *know* it is
2432 			 * safe, and trust userspace not to race with
2433 			 * itself
2434 			 */
2435 			rdev->sectors = oldsectors;
2436 			return -EBUSY;
2437 		}
2438 	}
2439 	return len;
2440 }
2441 
2442 static struct rdev_sysfs_entry rdev_size =
2443 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2444 
2445 static struct attribute *rdev_default_attrs[] = {
2446 	&rdev_state.attr,
2447 	&rdev_errors.attr,
2448 	&rdev_slot.attr,
2449 	&rdev_offset.attr,
2450 	&rdev_size.attr,
2451 	NULL,
2452 };
2453 static ssize_t
2454 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2455 {
2456 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2457 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2458 	mddev_t *mddev = rdev->mddev;
2459 	ssize_t rv;
2460 
2461 	if (!entry->show)
2462 		return -EIO;
2463 
2464 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2465 	if (!rv) {
2466 		if (rdev->mddev == NULL)
2467 			rv = -EBUSY;
2468 		else
2469 			rv = entry->show(rdev, page);
2470 		mddev_unlock(mddev);
2471 	}
2472 	return rv;
2473 }
2474 
2475 static ssize_t
2476 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2477 	      const char *page, size_t length)
2478 {
2479 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2480 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2481 	ssize_t rv;
2482 	mddev_t *mddev = rdev->mddev;
2483 
2484 	if (!entry->store)
2485 		return -EIO;
2486 	if (!capable(CAP_SYS_ADMIN))
2487 		return -EACCES;
2488 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2489 	if (!rv) {
2490 		if (rdev->mddev == NULL)
2491 			rv = -EBUSY;
2492 		else
2493 			rv = entry->store(rdev, page, length);
2494 		mddev_unlock(mddev);
2495 	}
2496 	return rv;
2497 }
2498 
2499 static void rdev_free(struct kobject *ko)
2500 {
2501 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2502 	kfree(rdev);
2503 }
2504 static struct sysfs_ops rdev_sysfs_ops = {
2505 	.show		= rdev_attr_show,
2506 	.store		= rdev_attr_store,
2507 };
2508 static struct kobj_type rdev_ktype = {
2509 	.release	= rdev_free,
2510 	.sysfs_ops	= &rdev_sysfs_ops,
2511 	.default_attrs	= rdev_default_attrs,
2512 };
2513 
2514 /*
2515  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2516  *
2517  * mark the device faulty if:
2518  *
2519  *   - the device is nonexistent (zero size)
2520  *   - the device has no valid superblock
2521  *
2522  * a faulty rdev _never_ has rdev->sb set.
2523  */
2524 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2525 {
2526 	char b[BDEVNAME_SIZE];
2527 	int err;
2528 	mdk_rdev_t *rdev;
2529 	sector_t size;
2530 
2531 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2532 	if (!rdev) {
2533 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2534 		return ERR_PTR(-ENOMEM);
2535 	}
2536 
2537 	if ((err = alloc_disk_sb(rdev)))
2538 		goto abort_free;
2539 
2540 	err = lock_rdev(rdev, newdev, super_format == -2);
2541 	if (err)
2542 		goto abort_free;
2543 
2544 	kobject_init(&rdev->kobj, &rdev_ktype);
2545 
2546 	rdev->desc_nr = -1;
2547 	rdev->saved_raid_disk = -1;
2548 	rdev->raid_disk = -1;
2549 	rdev->flags = 0;
2550 	rdev->data_offset = 0;
2551 	rdev->sb_events = 0;
2552 	atomic_set(&rdev->nr_pending, 0);
2553 	atomic_set(&rdev->read_errors, 0);
2554 	atomic_set(&rdev->corrected_errors, 0);
2555 
2556 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2557 	if (!size) {
2558 		printk(KERN_WARNING
2559 			"md: %s has zero or unknown size, marking faulty!\n",
2560 			bdevname(rdev->bdev,b));
2561 		err = -EINVAL;
2562 		goto abort_free;
2563 	}
2564 
2565 	if (super_format >= 0) {
2566 		err = super_types[super_format].
2567 			load_super(rdev, NULL, super_minor);
2568 		if (err == -EINVAL) {
2569 			printk(KERN_WARNING
2570 				"md: %s does not have a valid v%d.%d "
2571 			       "superblock, not importing!\n",
2572 				bdevname(rdev->bdev,b),
2573 			       super_format, super_minor);
2574 			goto abort_free;
2575 		}
2576 		if (err < 0) {
2577 			printk(KERN_WARNING
2578 				"md: could not read %s's sb, not importing!\n",
2579 				bdevname(rdev->bdev,b));
2580 			goto abort_free;
2581 		}
2582 	}
2583 
2584 	INIT_LIST_HEAD(&rdev->same_set);
2585 	init_waitqueue_head(&rdev->blocked_wait);
2586 
2587 	return rdev;
2588 
2589 abort_free:
2590 	if (rdev->sb_page) {
2591 		if (rdev->bdev)
2592 			unlock_rdev(rdev);
2593 		free_disk_sb(rdev);
2594 	}
2595 	kfree(rdev);
2596 	return ERR_PTR(err);
2597 }
2598 
2599 /*
2600  * Check a full RAID array for plausibility
2601  */
2602 
2603 
2604 static void analyze_sbs(mddev_t * mddev)
2605 {
2606 	int i;
2607 	mdk_rdev_t *rdev, *freshest, *tmp;
2608 	char b[BDEVNAME_SIZE];
2609 
2610 	freshest = NULL;
2611 	rdev_for_each(rdev, tmp, mddev)
2612 		switch (super_types[mddev->major_version].
2613 			load_super(rdev, freshest, mddev->minor_version)) {
2614 		case 1:
2615 			freshest = rdev;
2616 			break;
2617 		case 0:
2618 			break;
2619 		default:
2620 			printk( KERN_ERR \
2621 				"md: fatal superblock inconsistency in %s"
2622 				" -- removing from array\n",
2623 				bdevname(rdev->bdev,b));
2624 			kick_rdev_from_array(rdev);
2625 		}
2626 
2627 
2628 	super_types[mddev->major_version].
2629 		validate_super(mddev, freshest);
2630 
2631 	i = 0;
2632 	rdev_for_each(rdev, tmp, mddev) {
2633 		if (rdev->desc_nr >= mddev->max_disks ||
2634 		    i > mddev->max_disks) {
2635 			printk(KERN_WARNING
2636 			       "md: %s: %s: only %d devices permitted\n",
2637 			       mdname(mddev), bdevname(rdev->bdev, b),
2638 			       mddev->max_disks);
2639 			kick_rdev_from_array(rdev);
2640 			continue;
2641 		}
2642 		if (rdev != freshest)
2643 			if (super_types[mddev->major_version].
2644 			    validate_super(mddev, rdev)) {
2645 				printk(KERN_WARNING "md: kicking non-fresh %s"
2646 					" from array!\n",
2647 					bdevname(rdev->bdev,b));
2648 				kick_rdev_from_array(rdev);
2649 				continue;
2650 			}
2651 		if (mddev->level == LEVEL_MULTIPATH) {
2652 			rdev->desc_nr = i++;
2653 			rdev->raid_disk = rdev->desc_nr;
2654 			set_bit(In_sync, &rdev->flags);
2655 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
2656 			rdev->raid_disk = -1;
2657 			clear_bit(In_sync, &rdev->flags);
2658 		}
2659 	}
2660 }
2661 
2662 static void md_safemode_timeout(unsigned long data);
2663 
2664 static ssize_t
2665 safe_delay_show(mddev_t *mddev, char *page)
2666 {
2667 	int msec = (mddev->safemode_delay*1000)/HZ;
2668 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2669 }
2670 static ssize_t
2671 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2672 {
2673 	int scale=1;
2674 	int dot=0;
2675 	int i;
2676 	unsigned long msec;
2677 	char buf[30];
2678 
2679 	/* remove a period, and count digits after it */
2680 	if (len >= sizeof(buf))
2681 		return -EINVAL;
2682 	strlcpy(buf, cbuf, sizeof(buf));
2683 	for (i=0; i<len; i++) {
2684 		if (dot) {
2685 			if (isdigit(buf[i])) {
2686 				buf[i-1] = buf[i];
2687 				scale *= 10;
2688 			}
2689 			buf[i] = 0;
2690 		} else if (buf[i] == '.') {
2691 			dot=1;
2692 			buf[i] = 0;
2693 		}
2694 	}
2695 	if (strict_strtoul(buf, 10, &msec) < 0)
2696 		return -EINVAL;
2697 	msec = (msec * 1000) / scale;
2698 	if (msec == 0)
2699 		mddev->safemode_delay = 0;
2700 	else {
2701 		unsigned long old_delay = mddev->safemode_delay;
2702 		mddev->safemode_delay = (msec*HZ)/1000;
2703 		if (mddev->safemode_delay == 0)
2704 			mddev->safemode_delay = 1;
2705 		if (mddev->safemode_delay < old_delay)
2706 			md_safemode_timeout((unsigned long)mddev);
2707 	}
2708 	return len;
2709 }
2710 static struct md_sysfs_entry md_safe_delay =
2711 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2712 
2713 static ssize_t
2714 level_show(mddev_t *mddev, char *page)
2715 {
2716 	struct mdk_personality *p = mddev->pers;
2717 	if (p)
2718 		return sprintf(page, "%s\n", p->name);
2719 	else if (mddev->clevel[0])
2720 		return sprintf(page, "%s\n", mddev->clevel);
2721 	else if (mddev->level != LEVEL_NONE)
2722 		return sprintf(page, "%d\n", mddev->level);
2723 	else
2724 		return 0;
2725 }
2726 
2727 static ssize_t
2728 level_store(mddev_t *mddev, const char *buf, size_t len)
2729 {
2730 	char level[16];
2731 	ssize_t rv = len;
2732 	struct mdk_personality *pers;
2733 	void *priv;
2734 	mdk_rdev_t *rdev;
2735 
2736 	if (mddev->pers == NULL) {
2737 		if (len == 0)
2738 			return 0;
2739 		if (len >= sizeof(mddev->clevel))
2740 			return -ENOSPC;
2741 		strncpy(mddev->clevel, buf, len);
2742 		if (mddev->clevel[len-1] == '\n')
2743 			len--;
2744 		mddev->clevel[len] = 0;
2745 		mddev->level = LEVEL_NONE;
2746 		return rv;
2747 	}
2748 
2749 	/* request to change the personality.  Need to ensure:
2750 	 *  - array is not engaged in resync/recovery/reshape
2751 	 *  - old personality can be suspended
2752 	 *  - new personality will access other array.
2753 	 */
2754 
2755 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
2756 		return -EBUSY;
2757 
2758 	if (!mddev->pers->quiesce) {
2759 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
2760 		       mdname(mddev), mddev->pers->name);
2761 		return -EINVAL;
2762 	}
2763 
2764 	/* Now find the new personality */
2765 	if (len == 0 || len >= sizeof(level))
2766 		return -EINVAL;
2767 	strncpy(level, buf, len);
2768 	if (level[len-1] == '\n')
2769 		len--;
2770 	level[len] = 0;
2771 
2772 	request_module("md-%s", level);
2773 	spin_lock(&pers_lock);
2774 	pers = find_pers(LEVEL_NONE, level);
2775 	if (!pers || !try_module_get(pers->owner)) {
2776 		spin_unlock(&pers_lock);
2777 		printk(KERN_WARNING "md: personality %s not loaded\n", level);
2778 		return -EINVAL;
2779 	}
2780 	spin_unlock(&pers_lock);
2781 
2782 	if (pers == mddev->pers) {
2783 		/* Nothing to do! */
2784 		module_put(pers->owner);
2785 		return rv;
2786 	}
2787 	if (!pers->takeover) {
2788 		module_put(pers->owner);
2789 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
2790 		       mdname(mddev), level);
2791 		return -EINVAL;
2792 	}
2793 
2794 	/* ->takeover must set new_* and/or delta_disks
2795 	 * if it succeeds, and may set them when it fails.
2796 	 */
2797 	priv = pers->takeover(mddev);
2798 	if (IS_ERR(priv)) {
2799 		mddev->new_level = mddev->level;
2800 		mddev->new_layout = mddev->layout;
2801 		mddev->new_chunk_sectors = mddev->chunk_sectors;
2802 		mddev->raid_disks -= mddev->delta_disks;
2803 		mddev->delta_disks = 0;
2804 		module_put(pers->owner);
2805 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
2806 		       mdname(mddev), level);
2807 		return PTR_ERR(priv);
2808 	}
2809 
2810 	/* Looks like we have a winner */
2811 	mddev_suspend(mddev);
2812 	mddev->pers->stop(mddev);
2813 	module_put(mddev->pers->owner);
2814 	/* Invalidate devices that are now superfluous */
2815 	list_for_each_entry(rdev, &mddev->disks, same_set)
2816 		if (rdev->raid_disk >= mddev->raid_disks) {
2817 			rdev->raid_disk = -1;
2818 			clear_bit(In_sync, &rdev->flags);
2819 		}
2820 	mddev->pers = pers;
2821 	mddev->private = priv;
2822 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
2823 	mddev->level = mddev->new_level;
2824 	mddev->layout = mddev->new_layout;
2825 	mddev->chunk_sectors = mddev->new_chunk_sectors;
2826 	mddev->delta_disks = 0;
2827 	pers->run(mddev);
2828 	mddev_resume(mddev);
2829 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
2830 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2831 	md_wakeup_thread(mddev->thread);
2832 	return rv;
2833 }
2834 
2835 static struct md_sysfs_entry md_level =
2836 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
2837 
2838 
2839 static ssize_t
2840 layout_show(mddev_t *mddev, char *page)
2841 {
2842 	/* just a number, not meaningful for all levels */
2843 	if (mddev->reshape_position != MaxSector &&
2844 	    mddev->layout != mddev->new_layout)
2845 		return sprintf(page, "%d (%d)\n",
2846 			       mddev->new_layout, mddev->layout);
2847 	return sprintf(page, "%d\n", mddev->layout);
2848 }
2849 
2850 static ssize_t
2851 layout_store(mddev_t *mddev, const char *buf, size_t len)
2852 {
2853 	char *e;
2854 	unsigned long n = simple_strtoul(buf, &e, 10);
2855 
2856 	if (!*buf || (*e && *e != '\n'))
2857 		return -EINVAL;
2858 
2859 	if (mddev->pers) {
2860 		int err;
2861 		if (mddev->pers->check_reshape == NULL)
2862 			return -EBUSY;
2863 		mddev->new_layout = n;
2864 		err = mddev->pers->check_reshape(mddev);
2865 		if (err) {
2866 			mddev->new_layout = mddev->layout;
2867 			return err;
2868 		}
2869 	} else {
2870 		mddev->new_layout = n;
2871 		if (mddev->reshape_position == MaxSector)
2872 			mddev->layout = n;
2873 	}
2874 	return len;
2875 }
2876 static struct md_sysfs_entry md_layout =
2877 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
2878 
2879 
2880 static ssize_t
2881 raid_disks_show(mddev_t *mddev, char *page)
2882 {
2883 	if (mddev->raid_disks == 0)
2884 		return 0;
2885 	if (mddev->reshape_position != MaxSector &&
2886 	    mddev->delta_disks != 0)
2887 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
2888 			       mddev->raid_disks - mddev->delta_disks);
2889 	return sprintf(page, "%d\n", mddev->raid_disks);
2890 }
2891 
2892 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2893 
2894 static ssize_t
2895 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2896 {
2897 	char *e;
2898 	int rv = 0;
2899 	unsigned long n = simple_strtoul(buf, &e, 10);
2900 
2901 	if (!*buf || (*e && *e != '\n'))
2902 		return -EINVAL;
2903 
2904 	if (mddev->pers)
2905 		rv = update_raid_disks(mddev, n);
2906 	else if (mddev->reshape_position != MaxSector) {
2907 		int olddisks = mddev->raid_disks - mddev->delta_disks;
2908 		mddev->delta_disks = n - olddisks;
2909 		mddev->raid_disks = n;
2910 	} else
2911 		mddev->raid_disks = n;
2912 	return rv ? rv : len;
2913 }
2914 static struct md_sysfs_entry md_raid_disks =
2915 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
2916 
2917 static ssize_t
2918 chunk_size_show(mddev_t *mddev, char *page)
2919 {
2920 	if (mddev->reshape_position != MaxSector &&
2921 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
2922 		return sprintf(page, "%d (%d)\n",
2923 			       mddev->new_chunk_sectors << 9,
2924 			       mddev->chunk_sectors << 9);
2925 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
2926 }
2927 
2928 static ssize_t
2929 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2930 {
2931 	char *e;
2932 	unsigned long n = simple_strtoul(buf, &e, 10);
2933 
2934 	if (!*buf || (*e && *e != '\n'))
2935 		return -EINVAL;
2936 
2937 	if (mddev->pers) {
2938 		int err;
2939 		if (mddev->pers->check_reshape == NULL)
2940 			return -EBUSY;
2941 		mddev->new_chunk_sectors = n >> 9;
2942 		err = mddev->pers->check_reshape(mddev);
2943 		if (err) {
2944 			mddev->new_chunk_sectors = mddev->chunk_sectors;
2945 			return err;
2946 		}
2947 	} else {
2948 		mddev->new_chunk_sectors = n >> 9;
2949 		if (mddev->reshape_position == MaxSector)
2950 			mddev->chunk_sectors = n >> 9;
2951 	}
2952 	return len;
2953 }
2954 static struct md_sysfs_entry md_chunk_size =
2955 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
2956 
2957 static ssize_t
2958 resync_start_show(mddev_t *mddev, char *page)
2959 {
2960 	if (mddev->recovery_cp == MaxSector)
2961 		return sprintf(page, "none\n");
2962 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
2963 }
2964 
2965 static ssize_t
2966 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
2967 {
2968 	char *e;
2969 	unsigned long long n = simple_strtoull(buf, &e, 10);
2970 
2971 	if (mddev->pers)
2972 		return -EBUSY;
2973 	if (!*buf || (*e && *e != '\n'))
2974 		return -EINVAL;
2975 
2976 	mddev->recovery_cp = n;
2977 	return len;
2978 }
2979 static struct md_sysfs_entry md_resync_start =
2980 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
2981 
2982 /*
2983  * The array state can be:
2984  *
2985  * clear
2986  *     No devices, no size, no level
2987  *     Equivalent to STOP_ARRAY ioctl
2988  * inactive
2989  *     May have some settings, but array is not active
2990  *        all IO results in error
2991  *     When written, doesn't tear down array, but just stops it
2992  * suspended (not supported yet)
2993  *     All IO requests will block. The array can be reconfigured.
2994  *     Writing this, if accepted, will block until array is quiescent
2995  * readonly
2996  *     no resync can happen.  no superblocks get written.
2997  *     write requests fail
2998  * read-auto
2999  *     like readonly, but behaves like 'clean' on a write request.
3000  *
3001  * clean - no pending writes, but otherwise active.
3002  *     When written to inactive array, starts without resync
3003  *     If a write request arrives then
3004  *       if metadata is known, mark 'dirty' and switch to 'active'.
3005  *       if not known, block and switch to write-pending
3006  *     If written to an active array that has pending writes, then fails.
3007  * active
3008  *     fully active: IO and resync can be happening.
3009  *     When written to inactive array, starts with resync
3010  *
3011  * write-pending
3012  *     clean, but writes are blocked waiting for 'active' to be written.
3013  *
3014  * active-idle
3015  *     like active, but no writes have been seen for a while (100msec).
3016  *
3017  */
3018 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3019 		   write_pending, active_idle, bad_word};
3020 static char *array_states[] = {
3021 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3022 	"write-pending", "active-idle", NULL };
3023 
3024 static int match_word(const char *word, char **list)
3025 {
3026 	int n;
3027 	for (n=0; list[n]; n++)
3028 		if (cmd_match(word, list[n]))
3029 			break;
3030 	return n;
3031 }
3032 
3033 static ssize_t
3034 array_state_show(mddev_t *mddev, char *page)
3035 {
3036 	enum array_state st = inactive;
3037 
3038 	if (mddev->pers)
3039 		switch(mddev->ro) {
3040 		case 1:
3041 			st = readonly;
3042 			break;
3043 		case 2:
3044 			st = read_auto;
3045 			break;
3046 		case 0:
3047 			if (mddev->in_sync)
3048 				st = clean;
3049 			else if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
3050 				st = write_pending;
3051 			else if (mddev->safemode)
3052 				st = active_idle;
3053 			else
3054 				st = active;
3055 		}
3056 	else {
3057 		if (list_empty(&mddev->disks) &&
3058 		    mddev->raid_disks == 0 &&
3059 		    mddev->dev_sectors == 0)
3060 			st = clear;
3061 		else
3062 			st = inactive;
3063 	}
3064 	return sprintf(page, "%s\n", array_states[st]);
3065 }
3066 
3067 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3068 static int do_md_run(mddev_t * mddev);
3069 static int restart_array(mddev_t *mddev);
3070 
3071 static ssize_t
3072 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3073 {
3074 	int err = -EINVAL;
3075 	enum array_state st = match_word(buf, array_states);
3076 	switch(st) {
3077 	case bad_word:
3078 		break;
3079 	case clear:
3080 		/* stopping an active array */
3081 		if (atomic_read(&mddev->openers) > 0)
3082 			return -EBUSY;
3083 		err = do_md_stop(mddev, 0, 0);
3084 		break;
3085 	case inactive:
3086 		/* stopping an active array */
3087 		if (mddev->pers) {
3088 			if (atomic_read(&mddev->openers) > 0)
3089 				return -EBUSY;
3090 			err = do_md_stop(mddev, 2, 0);
3091 		} else
3092 			err = 0; /* already inactive */
3093 		break;
3094 	case suspended:
3095 		break; /* not supported yet */
3096 	case readonly:
3097 		if (mddev->pers)
3098 			err = do_md_stop(mddev, 1, 0);
3099 		else {
3100 			mddev->ro = 1;
3101 			set_disk_ro(mddev->gendisk, 1);
3102 			err = do_md_run(mddev);
3103 		}
3104 		break;
3105 	case read_auto:
3106 		if (mddev->pers) {
3107 			if (mddev->ro == 0)
3108 				err = do_md_stop(mddev, 1, 0);
3109 			else if (mddev->ro == 1)
3110 				err = restart_array(mddev);
3111 			if (err == 0) {
3112 				mddev->ro = 2;
3113 				set_disk_ro(mddev->gendisk, 0);
3114 			}
3115 		} else {
3116 			mddev->ro = 2;
3117 			err = do_md_run(mddev);
3118 		}
3119 		break;
3120 	case clean:
3121 		if (mddev->pers) {
3122 			restart_array(mddev);
3123 			spin_lock_irq(&mddev->write_lock);
3124 			if (atomic_read(&mddev->writes_pending) == 0) {
3125 				if (mddev->in_sync == 0) {
3126 					mddev->in_sync = 1;
3127 					if (mddev->safemode == 1)
3128 						mddev->safemode = 0;
3129 					if (mddev->persistent)
3130 						set_bit(MD_CHANGE_CLEAN,
3131 							&mddev->flags);
3132 				}
3133 				err = 0;
3134 			} else
3135 				err = -EBUSY;
3136 			spin_unlock_irq(&mddev->write_lock);
3137 		} else
3138 			err = -EINVAL;
3139 		break;
3140 	case active:
3141 		if (mddev->pers) {
3142 			restart_array(mddev);
3143 			if (mddev->external)
3144 				clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
3145 			wake_up(&mddev->sb_wait);
3146 			err = 0;
3147 		} else {
3148 			mddev->ro = 0;
3149 			set_disk_ro(mddev->gendisk, 0);
3150 			err = do_md_run(mddev);
3151 		}
3152 		break;
3153 	case write_pending:
3154 	case active_idle:
3155 		/* these cannot be set */
3156 		break;
3157 	}
3158 	if (err)
3159 		return err;
3160 	else {
3161 		sysfs_notify_dirent(mddev->sysfs_state);
3162 		return len;
3163 	}
3164 }
3165 static struct md_sysfs_entry md_array_state =
3166 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3167 
3168 static ssize_t
3169 null_show(mddev_t *mddev, char *page)
3170 {
3171 	return -EINVAL;
3172 }
3173 
3174 static ssize_t
3175 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3176 {
3177 	/* buf must be %d:%d\n? giving major and minor numbers */
3178 	/* The new device is added to the array.
3179 	 * If the array has a persistent superblock, we read the
3180 	 * superblock to initialise info and check validity.
3181 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3182 	 * which mainly checks size.
3183 	 */
3184 	char *e;
3185 	int major = simple_strtoul(buf, &e, 10);
3186 	int minor;
3187 	dev_t dev;
3188 	mdk_rdev_t *rdev;
3189 	int err;
3190 
3191 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3192 		return -EINVAL;
3193 	minor = simple_strtoul(e+1, &e, 10);
3194 	if (*e && *e != '\n')
3195 		return -EINVAL;
3196 	dev = MKDEV(major, minor);
3197 	if (major != MAJOR(dev) ||
3198 	    minor != MINOR(dev))
3199 		return -EOVERFLOW;
3200 
3201 
3202 	if (mddev->persistent) {
3203 		rdev = md_import_device(dev, mddev->major_version,
3204 					mddev->minor_version);
3205 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3206 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3207 						       mdk_rdev_t, same_set);
3208 			err = super_types[mddev->major_version]
3209 				.load_super(rdev, rdev0, mddev->minor_version);
3210 			if (err < 0)
3211 				goto out;
3212 		}
3213 	} else if (mddev->external)
3214 		rdev = md_import_device(dev, -2, -1);
3215 	else
3216 		rdev = md_import_device(dev, -1, -1);
3217 
3218 	if (IS_ERR(rdev))
3219 		return PTR_ERR(rdev);
3220 	err = bind_rdev_to_array(rdev, mddev);
3221  out:
3222 	if (err)
3223 		export_rdev(rdev);
3224 	return err ? err : len;
3225 }
3226 
3227 static struct md_sysfs_entry md_new_device =
3228 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3229 
3230 static ssize_t
3231 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3232 {
3233 	char *end;
3234 	unsigned long chunk, end_chunk;
3235 
3236 	if (!mddev->bitmap)
3237 		goto out;
3238 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3239 	while (*buf) {
3240 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3241 		if (buf == end) break;
3242 		if (*end == '-') { /* range */
3243 			buf = end + 1;
3244 			end_chunk = simple_strtoul(buf, &end, 0);
3245 			if (buf == end) break;
3246 		}
3247 		if (*end && !isspace(*end)) break;
3248 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3249 		buf = end;
3250 		while (isspace(*buf)) buf++;
3251 	}
3252 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3253 out:
3254 	return len;
3255 }
3256 
3257 static struct md_sysfs_entry md_bitmap =
3258 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3259 
3260 static ssize_t
3261 size_show(mddev_t *mddev, char *page)
3262 {
3263 	return sprintf(page, "%llu\n",
3264 		(unsigned long long)mddev->dev_sectors / 2);
3265 }
3266 
3267 static int update_size(mddev_t *mddev, sector_t num_sectors);
3268 
3269 static ssize_t
3270 size_store(mddev_t *mddev, const char *buf, size_t len)
3271 {
3272 	/* If array is inactive, we can reduce the component size, but
3273 	 * not increase it (except from 0).
3274 	 * If array is active, we can try an on-line resize
3275 	 */
3276 	sector_t sectors;
3277 	int err = strict_blocks_to_sectors(buf, &sectors);
3278 
3279 	if (err < 0)
3280 		return err;
3281 	if (mddev->pers) {
3282 		err = update_size(mddev, sectors);
3283 		md_update_sb(mddev, 1);
3284 	} else {
3285 		if (mddev->dev_sectors == 0 ||
3286 		    mddev->dev_sectors > sectors)
3287 			mddev->dev_sectors = sectors;
3288 		else
3289 			err = -ENOSPC;
3290 	}
3291 	return err ? err : len;
3292 }
3293 
3294 static struct md_sysfs_entry md_size =
3295 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3296 
3297 
3298 /* Metdata version.
3299  * This is one of
3300  *   'none' for arrays with no metadata (good luck...)
3301  *   'external' for arrays with externally managed metadata,
3302  * or N.M for internally known formats
3303  */
3304 static ssize_t
3305 metadata_show(mddev_t *mddev, char *page)
3306 {
3307 	if (mddev->persistent)
3308 		return sprintf(page, "%d.%d\n",
3309 			       mddev->major_version, mddev->minor_version);
3310 	else if (mddev->external)
3311 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3312 	else
3313 		return sprintf(page, "none\n");
3314 }
3315 
3316 static ssize_t
3317 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3318 {
3319 	int major, minor;
3320 	char *e;
3321 	/* Changing the details of 'external' metadata is
3322 	 * always permitted.  Otherwise there must be
3323 	 * no devices attached to the array.
3324 	 */
3325 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3326 		;
3327 	else if (!list_empty(&mddev->disks))
3328 		return -EBUSY;
3329 
3330 	if (cmd_match(buf, "none")) {
3331 		mddev->persistent = 0;
3332 		mddev->external = 0;
3333 		mddev->major_version = 0;
3334 		mddev->minor_version = 90;
3335 		return len;
3336 	}
3337 	if (strncmp(buf, "external:", 9) == 0) {
3338 		size_t namelen = len-9;
3339 		if (namelen >= sizeof(mddev->metadata_type))
3340 			namelen = sizeof(mddev->metadata_type)-1;
3341 		strncpy(mddev->metadata_type, buf+9, namelen);
3342 		mddev->metadata_type[namelen] = 0;
3343 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3344 			mddev->metadata_type[--namelen] = 0;
3345 		mddev->persistent = 0;
3346 		mddev->external = 1;
3347 		mddev->major_version = 0;
3348 		mddev->minor_version = 90;
3349 		return len;
3350 	}
3351 	major = simple_strtoul(buf, &e, 10);
3352 	if (e==buf || *e != '.')
3353 		return -EINVAL;
3354 	buf = e+1;
3355 	minor = simple_strtoul(buf, &e, 10);
3356 	if (e==buf || (*e && *e != '\n') )
3357 		return -EINVAL;
3358 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3359 		return -ENOENT;
3360 	mddev->major_version = major;
3361 	mddev->minor_version = minor;
3362 	mddev->persistent = 1;
3363 	mddev->external = 0;
3364 	return len;
3365 }
3366 
3367 static struct md_sysfs_entry md_metadata =
3368 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3369 
3370 static ssize_t
3371 action_show(mddev_t *mddev, char *page)
3372 {
3373 	char *type = "idle";
3374 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3375 		type = "frozen";
3376 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3377 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3378 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3379 			type = "reshape";
3380 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3381 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3382 				type = "resync";
3383 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3384 				type = "check";
3385 			else
3386 				type = "repair";
3387 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3388 			type = "recover";
3389 	}
3390 	return sprintf(page, "%s\n", type);
3391 }
3392 
3393 static ssize_t
3394 action_store(mddev_t *mddev, const char *page, size_t len)
3395 {
3396 	if (!mddev->pers || !mddev->pers->sync_request)
3397 		return -EINVAL;
3398 
3399 	if (cmd_match(page, "frozen"))
3400 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3401 	else
3402 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3403 
3404 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
3405 		if (mddev->sync_thread) {
3406 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3407 			md_unregister_thread(mddev->sync_thread);
3408 			mddev->sync_thread = NULL;
3409 			mddev->recovery = 0;
3410 		}
3411 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3412 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3413 		return -EBUSY;
3414 	else if (cmd_match(page, "resync"))
3415 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3416 	else if (cmd_match(page, "recover")) {
3417 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3418 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3419 	} else if (cmd_match(page, "reshape")) {
3420 		int err;
3421 		if (mddev->pers->start_reshape == NULL)
3422 			return -EINVAL;
3423 		err = mddev->pers->start_reshape(mddev);
3424 		if (err)
3425 			return err;
3426 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3427 	} else {
3428 		if (cmd_match(page, "check"))
3429 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3430 		else if (!cmd_match(page, "repair"))
3431 			return -EINVAL;
3432 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3433 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3434 	}
3435 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3436 	md_wakeup_thread(mddev->thread);
3437 	sysfs_notify_dirent(mddev->sysfs_action);
3438 	return len;
3439 }
3440 
3441 static ssize_t
3442 mismatch_cnt_show(mddev_t *mddev, char *page)
3443 {
3444 	return sprintf(page, "%llu\n",
3445 		       (unsigned long long) mddev->resync_mismatches);
3446 }
3447 
3448 static struct md_sysfs_entry md_scan_mode =
3449 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3450 
3451 
3452 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3453 
3454 static ssize_t
3455 sync_min_show(mddev_t *mddev, char *page)
3456 {
3457 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3458 		       mddev->sync_speed_min ? "local": "system");
3459 }
3460 
3461 static ssize_t
3462 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3463 {
3464 	int min;
3465 	char *e;
3466 	if (strncmp(buf, "system", 6)==0) {
3467 		mddev->sync_speed_min = 0;
3468 		return len;
3469 	}
3470 	min = simple_strtoul(buf, &e, 10);
3471 	if (buf == e || (*e && *e != '\n') || min <= 0)
3472 		return -EINVAL;
3473 	mddev->sync_speed_min = min;
3474 	return len;
3475 }
3476 
3477 static struct md_sysfs_entry md_sync_min =
3478 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3479 
3480 static ssize_t
3481 sync_max_show(mddev_t *mddev, char *page)
3482 {
3483 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3484 		       mddev->sync_speed_max ? "local": "system");
3485 }
3486 
3487 static ssize_t
3488 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3489 {
3490 	int max;
3491 	char *e;
3492 	if (strncmp(buf, "system", 6)==0) {
3493 		mddev->sync_speed_max = 0;
3494 		return len;
3495 	}
3496 	max = simple_strtoul(buf, &e, 10);
3497 	if (buf == e || (*e && *e != '\n') || max <= 0)
3498 		return -EINVAL;
3499 	mddev->sync_speed_max = max;
3500 	return len;
3501 }
3502 
3503 static struct md_sysfs_entry md_sync_max =
3504 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3505 
3506 static ssize_t
3507 degraded_show(mddev_t *mddev, char *page)
3508 {
3509 	return sprintf(page, "%d\n", mddev->degraded);
3510 }
3511 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3512 
3513 static ssize_t
3514 sync_force_parallel_show(mddev_t *mddev, char *page)
3515 {
3516 	return sprintf(page, "%d\n", mddev->parallel_resync);
3517 }
3518 
3519 static ssize_t
3520 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3521 {
3522 	long n;
3523 
3524 	if (strict_strtol(buf, 10, &n))
3525 		return -EINVAL;
3526 
3527 	if (n != 0 && n != 1)
3528 		return -EINVAL;
3529 
3530 	mddev->parallel_resync = n;
3531 
3532 	if (mddev->sync_thread)
3533 		wake_up(&resync_wait);
3534 
3535 	return len;
3536 }
3537 
3538 /* force parallel resync, even with shared block devices */
3539 static struct md_sysfs_entry md_sync_force_parallel =
3540 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3541        sync_force_parallel_show, sync_force_parallel_store);
3542 
3543 static ssize_t
3544 sync_speed_show(mddev_t *mddev, char *page)
3545 {
3546 	unsigned long resync, dt, db;
3547 	if (mddev->curr_resync == 0)
3548 		return sprintf(page, "none\n");
3549 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3550 	dt = (jiffies - mddev->resync_mark) / HZ;
3551 	if (!dt) dt++;
3552 	db = resync - mddev->resync_mark_cnt;
3553 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3554 }
3555 
3556 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3557 
3558 static ssize_t
3559 sync_completed_show(mddev_t *mddev, char *page)
3560 {
3561 	unsigned long max_sectors, resync;
3562 
3563 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3564 		return sprintf(page, "none\n");
3565 
3566 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3567 		max_sectors = mddev->resync_max_sectors;
3568 	else
3569 		max_sectors = mddev->dev_sectors;
3570 
3571 	resync = mddev->curr_resync_completed;
3572 	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
3573 }
3574 
3575 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3576 
3577 static ssize_t
3578 min_sync_show(mddev_t *mddev, char *page)
3579 {
3580 	return sprintf(page, "%llu\n",
3581 		       (unsigned long long)mddev->resync_min);
3582 }
3583 static ssize_t
3584 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3585 {
3586 	unsigned long long min;
3587 	if (strict_strtoull(buf, 10, &min))
3588 		return -EINVAL;
3589 	if (min > mddev->resync_max)
3590 		return -EINVAL;
3591 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3592 		return -EBUSY;
3593 
3594 	/* Must be a multiple of chunk_size */
3595 	if (mddev->chunk_sectors) {
3596 		sector_t temp = min;
3597 		if (sector_div(temp, mddev->chunk_sectors))
3598 			return -EINVAL;
3599 	}
3600 	mddev->resync_min = min;
3601 
3602 	return len;
3603 }
3604 
3605 static struct md_sysfs_entry md_min_sync =
3606 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3607 
3608 static ssize_t
3609 max_sync_show(mddev_t *mddev, char *page)
3610 {
3611 	if (mddev->resync_max == MaxSector)
3612 		return sprintf(page, "max\n");
3613 	else
3614 		return sprintf(page, "%llu\n",
3615 			       (unsigned long long)mddev->resync_max);
3616 }
3617 static ssize_t
3618 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3619 {
3620 	if (strncmp(buf, "max", 3) == 0)
3621 		mddev->resync_max = MaxSector;
3622 	else {
3623 		unsigned long long max;
3624 		if (strict_strtoull(buf, 10, &max))
3625 			return -EINVAL;
3626 		if (max < mddev->resync_min)
3627 			return -EINVAL;
3628 		if (max < mddev->resync_max &&
3629 		    mddev->ro == 0 &&
3630 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3631 			return -EBUSY;
3632 
3633 		/* Must be a multiple of chunk_size */
3634 		if (mddev->chunk_sectors) {
3635 			sector_t temp = max;
3636 			if (sector_div(temp, mddev->chunk_sectors))
3637 				return -EINVAL;
3638 		}
3639 		mddev->resync_max = max;
3640 	}
3641 	wake_up(&mddev->recovery_wait);
3642 	return len;
3643 }
3644 
3645 static struct md_sysfs_entry md_max_sync =
3646 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
3647 
3648 static ssize_t
3649 suspend_lo_show(mddev_t *mddev, char *page)
3650 {
3651 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
3652 }
3653 
3654 static ssize_t
3655 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
3656 {
3657 	char *e;
3658 	unsigned long long new = simple_strtoull(buf, &e, 10);
3659 
3660 	if (mddev->pers == NULL ||
3661 	    mddev->pers->quiesce == NULL)
3662 		return -EINVAL;
3663 	if (buf == e || (*e && *e != '\n'))
3664 		return -EINVAL;
3665 	if (new >= mddev->suspend_hi ||
3666 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
3667 		mddev->suspend_lo = new;
3668 		mddev->pers->quiesce(mddev, 2);
3669 		return len;
3670 	} else
3671 		return -EINVAL;
3672 }
3673 static struct md_sysfs_entry md_suspend_lo =
3674 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
3675 
3676 
3677 static ssize_t
3678 suspend_hi_show(mddev_t *mddev, char *page)
3679 {
3680 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
3681 }
3682 
3683 static ssize_t
3684 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
3685 {
3686 	char *e;
3687 	unsigned long long new = simple_strtoull(buf, &e, 10);
3688 
3689 	if (mddev->pers == NULL ||
3690 	    mddev->pers->quiesce == NULL)
3691 		return -EINVAL;
3692 	if (buf == e || (*e && *e != '\n'))
3693 		return -EINVAL;
3694 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
3695 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
3696 		mddev->suspend_hi = new;
3697 		mddev->pers->quiesce(mddev, 1);
3698 		mddev->pers->quiesce(mddev, 0);
3699 		return len;
3700 	} else
3701 		return -EINVAL;
3702 }
3703 static struct md_sysfs_entry md_suspend_hi =
3704 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
3705 
3706 static ssize_t
3707 reshape_position_show(mddev_t *mddev, char *page)
3708 {
3709 	if (mddev->reshape_position != MaxSector)
3710 		return sprintf(page, "%llu\n",
3711 			       (unsigned long long)mddev->reshape_position);
3712 	strcpy(page, "none\n");
3713 	return 5;
3714 }
3715 
3716 static ssize_t
3717 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
3718 {
3719 	char *e;
3720 	unsigned long long new = simple_strtoull(buf, &e, 10);
3721 	if (mddev->pers)
3722 		return -EBUSY;
3723 	if (buf == e || (*e && *e != '\n'))
3724 		return -EINVAL;
3725 	mddev->reshape_position = new;
3726 	mddev->delta_disks = 0;
3727 	mddev->new_level = mddev->level;
3728 	mddev->new_layout = mddev->layout;
3729 	mddev->new_chunk_sectors = mddev->chunk_sectors;
3730 	return len;
3731 }
3732 
3733 static struct md_sysfs_entry md_reshape_position =
3734 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
3735        reshape_position_store);
3736 
3737 static ssize_t
3738 array_size_show(mddev_t *mddev, char *page)
3739 {
3740 	if (mddev->external_size)
3741 		return sprintf(page, "%llu\n",
3742 			       (unsigned long long)mddev->array_sectors/2);
3743 	else
3744 		return sprintf(page, "default\n");
3745 }
3746 
3747 static ssize_t
3748 array_size_store(mddev_t *mddev, const char *buf, size_t len)
3749 {
3750 	sector_t sectors;
3751 
3752 	if (strncmp(buf, "default", 7) == 0) {
3753 		if (mddev->pers)
3754 			sectors = mddev->pers->size(mddev, 0, 0);
3755 		else
3756 			sectors = mddev->array_sectors;
3757 
3758 		mddev->external_size = 0;
3759 	} else {
3760 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
3761 			return -EINVAL;
3762 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
3763 			return -E2BIG;
3764 
3765 		mddev->external_size = 1;
3766 	}
3767 
3768 	mddev->array_sectors = sectors;
3769 	set_capacity(mddev->gendisk, mddev->array_sectors);
3770 	if (mddev->pers)
3771 		revalidate_disk(mddev->gendisk);
3772 
3773 	return len;
3774 }
3775 
3776 static struct md_sysfs_entry md_array_size =
3777 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
3778        array_size_store);
3779 
3780 static struct attribute *md_default_attrs[] = {
3781 	&md_level.attr,
3782 	&md_layout.attr,
3783 	&md_raid_disks.attr,
3784 	&md_chunk_size.attr,
3785 	&md_size.attr,
3786 	&md_resync_start.attr,
3787 	&md_metadata.attr,
3788 	&md_new_device.attr,
3789 	&md_safe_delay.attr,
3790 	&md_array_state.attr,
3791 	&md_reshape_position.attr,
3792 	&md_array_size.attr,
3793 	NULL,
3794 };
3795 
3796 static struct attribute *md_redundancy_attrs[] = {
3797 	&md_scan_mode.attr,
3798 	&md_mismatches.attr,
3799 	&md_sync_min.attr,
3800 	&md_sync_max.attr,
3801 	&md_sync_speed.attr,
3802 	&md_sync_force_parallel.attr,
3803 	&md_sync_completed.attr,
3804 	&md_min_sync.attr,
3805 	&md_max_sync.attr,
3806 	&md_suspend_lo.attr,
3807 	&md_suspend_hi.attr,
3808 	&md_bitmap.attr,
3809 	&md_degraded.attr,
3810 	NULL,
3811 };
3812 static struct attribute_group md_redundancy_group = {
3813 	.name = NULL,
3814 	.attrs = md_redundancy_attrs,
3815 };
3816 
3817 
3818 static ssize_t
3819 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3820 {
3821 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3822 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3823 	ssize_t rv;
3824 
3825 	if (!entry->show)
3826 		return -EIO;
3827 	rv = mddev_lock(mddev);
3828 	if (!rv) {
3829 		rv = entry->show(mddev, page);
3830 		mddev_unlock(mddev);
3831 	}
3832 	return rv;
3833 }
3834 
3835 static ssize_t
3836 md_attr_store(struct kobject *kobj, struct attribute *attr,
3837 	      const char *page, size_t length)
3838 {
3839 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3840 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3841 	ssize_t rv;
3842 
3843 	if (!entry->store)
3844 		return -EIO;
3845 	if (!capable(CAP_SYS_ADMIN))
3846 		return -EACCES;
3847 	rv = mddev_lock(mddev);
3848 	if (mddev->hold_active == UNTIL_IOCTL)
3849 		mddev->hold_active = 0;
3850 	if (!rv) {
3851 		rv = entry->store(mddev, page, length);
3852 		mddev_unlock(mddev);
3853 	}
3854 	return rv;
3855 }
3856 
3857 static void md_free(struct kobject *ko)
3858 {
3859 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
3860 
3861 	if (mddev->sysfs_state)
3862 		sysfs_put(mddev->sysfs_state);
3863 
3864 	if (mddev->gendisk) {
3865 		del_gendisk(mddev->gendisk);
3866 		put_disk(mddev->gendisk);
3867 	}
3868 	if (mddev->queue)
3869 		blk_cleanup_queue(mddev->queue);
3870 
3871 	kfree(mddev);
3872 }
3873 
3874 static struct sysfs_ops md_sysfs_ops = {
3875 	.show	= md_attr_show,
3876 	.store	= md_attr_store,
3877 };
3878 static struct kobj_type md_ktype = {
3879 	.release	= md_free,
3880 	.sysfs_ops	= &md_sysfs_ops,
3881 	.default_attrs	= md_default_attrs,
3882 };
3883 
3884 int mdp_major = 0;
3885 
3886 static void mddev_delayed_delete(struct work_struct *ws)
3887 {
3888 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
3889 
3890 	if (mddev->private == &md_redundancy_group) {
3891 		sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
3892 		if (mddev->sysfs_action)
3893 			sysfs_put(mddev->sysfs_action);
3894 		mddev->sysfs_action = NULL;
3895 		mddev->private = NULL;
3896 	}
3897 	kobject_del(&mddev->kobj);
3898 	kobject_put(&mddev->kobj);
3899 }
3900 
3901 static int md_alloc(dev_t dev, char *name)
3902 {
3903 	static DEFINE_MUTEX(disks_mutex);
3904 	mddev_t *mddev = mddev_find(dev);
3905 	struct gendisk *disk;
3906 	int partitioned;
3907 	int shift;
3908 	int unit;
3909 	int error;
3910 
3911 	if (!mddev)
3912 		return -ENODEV;
3913 
3914 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
3915 	shift = partitioned ? MdpMinorShift : 0;
3916 	unit = MINOR(mddev->unit) >> shift;
3917 
3918 	/* wait for any previous instance if this device
3919 	 * to be completed removed (mddev_delayed_delete).
3920 	 */
3921 	flush_scheduled_work();
3922 
3923 	mutex_lock(&disks_mutex);
3924 	error = -EEXIST;
3925 	if (mddev->gendisk)
3926 		goto abort;
3927 
3928 	if (name) {
3929 		/* Need to ensure that 'name' is not a duplicate.
3930 		 */
3931 		mddev_t *mddev2;
3932 		spin_lock(&all_mddevs_lock);
3933 
3934 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
3935 			if (mddev2->gendisk &&
3936 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
3937 				spin_unlock(&all_mddevs_lock);
3938 				goto abort;
3939 			}
3940 		spin_unlock(&all_mddevs_lock);
3941 	}
3942 
3943 	error = -ENOMEM;
3944 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
3945 	if (!mddev->queue)
3946 		goto abort;
3947 	mddev->queue->queuedata = mddev;
3948 
3949 	/* Can be unlocked because the queue is new: no concurrency */
3950 	queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
3951 
3952 	blk_queue_make_request(mddev->queue, md_make_request);
3953 
3954 	disk = alloc_disk(1 << shift);
3955 	if (!disk) {
3956 		blk_cleanup_queue(mddev->queue);
3957 		mddev->queue = NULL;
3958 		goto abort;
3959 	}
3960 	disk->major = MAJOR(mddev->unit);
3961 	disk->first_minor = unit << shift;
3962 	if (name)
3963 		strcpy(disk->disk_name, name);
3964 	else if (partitioned)
3965 		sprintf(disk->disk_name, "md_d%d", unit);
3966 	else
3967 		sprintf(disk->disk_name, "md%d", unit);
3968 	disk->fops = &md_fops;
3969 	disk->private_data = mddev;
3970 	disk->queue = mddev->queue;
3971 	/* Allow extended partitions.  This makes the
3972 	 * 'mdp' device redundant, but we can't really
3973 	 * remove it now.
3974 	 */
3975 	disk->flags |= GENHD_FL_EXT_DEVT;
3976 	add_disk(disk);
3977 	mddev->gendisk = disk;
3978 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
3979 				     &disk_to_dev(disk)->kobj, "%s", "md");
3980 	if (error) {
3981 		/* This isn't possible, but as kobject_init_and_add is marked
3982 		 * __must_check, we must do something with the result
3983 		 */
3984 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
3985 		       disk->disk_name);
3986 		error = 0;
3987 	}
3988  abort:
3989 	mutex_unlock(&disks_mutex);
3990 	if (!error) {
3991 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
3992 		mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
3993 	}
3994 	mddev_put(mddev);
3995 	return error;
3996 }
3997 
3998 static struct kobject *md_probe(dev_t dev, int *part, void *data)
3999 {
4000 	md_alloc(dev, NULL);
4001 	return NULL;
4002 }
4003 
4004 static int add_named_array(const char *val, struct kernel_param *kp)
4005 {
4006 	/* val must be "md_*" where * is not all digits.
4007 	 * We allocate an array with a large free minor number, and
4008 	 * set the name to val.  val must not already be an active name.
4009 	 */
4010 	int len = strlen(val);
4011 	char buf[DISK_NAME_LEN];
4012 
4013 	while (len && val[len-1] == '\n')
4014 		len--;
4015 	if (len >= DISK_NAME_LEN)
4016 		return -E2BIG;
4017 	strlcpy(buf, val, len+1);
4018 	if (strncmp(buf, "md_", 3) != 0)
4019 		return -EINVAL;
4020 	return md_alloc(0, buf);
4021 }
4022 
4023 static void md_safemode_timeout(unsigned long data)
4024 {
4025 	mddev_t *mddev = (mddev_t *) data;
4026 
4027 	if (!atomic_read(&mddev->writes_pending)) {
4028 		mddev->safemode = 1;
4029 		if (mddev->external)
4030 			sysfs_notify_dirent(mddev->sysfs_state);
4031 	}
4032 	md_wakeup_thread(mddev->thread);
4033 }
4034 
4035 static int start_dirty_degraded;
4036 
4037 static int do_md_run(mddev_t * mddev)
4038 {
4039 	int err;
4040 	mdk_rdev_t *rdev;
4041 	struct gendisk *disk;
4042 	struct mdk_personality *pers;
4043 
4044 	if (list_empty(&mddev->disks))
4045 		/* cannot run an array with no devices.. */
4046 		return -EINVAL;
4047 
4048 	if (mddev->pers)
4049 		return -EBUSY;
4050 
4051 	/*
4052 	 * Analyze all RAID superblock(s)
4053 	 */
4054 	if (!mddev->raid_disks) {
4055 		if (!mddev->persistent)
4056 			return -EINVAL;
4057 		analyze_sbs(mddev);
4058 	}
4059 
4060 	if (mddev->level != LEVEL_NONE)
4061 		request_module("md-level-%d", mddev->level);
4062 	else if (mddev->clevel[0])
4063 		request_module("md-%s", mddev->clevel);
4064 
4065 	/*
4066 	 * Drop all container device buffers, from now on
4067 	 * the only valid external interface is through the md
4068 	 * device.
4069 	 */
4070 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4071 		if (test_bit(Faulty, &rdev->flags))
4072 			continue;
4073 		sync_blockdev(rdev->bdev);
4074 		invalidate_bdev(rdev->bdev);
4075 
4076 		/* perform some consistency tests on the device.
4077 		 * We don't want the data to overlap the metadata,
4078 		 * Internal Bitmap issues have been handled elsewhere.
4079 		 */
4080 		if (rdev->data_offset < rdev->sb_start) {
4081 			if (mddev->dev_sectors &&
4082 			    rdev->data_offset + mddev->dev_sectors
4083 			    > rdev->sb_start) {
4084 				printk("md: %s: data overlaps metadata\n",
4085 				       mdname(mddev));
4086 				return -EINVAL;
4087 			}
4088 		} else {
4089 			if (rdev->sb_start + rdev->sb_size/512
4090 			    > rdev->data_offset) {
4091 				printk("md: %s: metadata overlaps data\n",
4092 				       mdname(mddev));
4093 				return -EINVAL;
4094 			}
4095 		}
4096 		sysfs_notify_dirent(rdev->sysfs_state);
4097 	}
4098 
4099 	md_probe(mddev->unit, NULL, NULL);
4100 	disk = mddev->gendisk;
4101 	if (!disk)
4102 		return -ENOMEM;
4103 
4104 	spin_lock(&pers_lock);
4105 	pers = find_pers(mddev->level, mddev->clevel);
4106 	if (!pers || !try_module_get(pers->owner)) {
4107 		spin_unlock(&pers_lock);
4108 		if (mddev->level != LEVEL_NONE)
4109 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4110 			       mddev->level);
4111 		else
4112 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4113 			       mddev->clevel);
4114 		return -EINVAL;
4115 	}
4116 	mddev->pers = pers;
4117 	spin_unlock(&pers_lock);
4118 	if (mddev->level != pers->level) {
4119 		mddev->level = pers->level;
4120 		mddev->new_level = pers->level;
4121 	}
4122 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4123 
4124 	if (mddev->reshape_position != MaxSector &&
4125 	    pers->start_reshape == NULL) {
4126 		/* This personality cannot handle reshaping... */
4127 		mddev->pers = NULL;
4128 		module_put(pers->owner);
4129 		return -EINVAL;
4130 	}
4131 
4132 	if (pers->sync_request) {
4133 		/* Warn if this is a potentially silly
4134 		 * configuration.
4135 		 */
4136 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4137 		mdk_rdev_t *rdev2;
4138 		int warned = 0;
4139 
4140 		list_for_each_entry(rdev, &mddev->disks, same_set)
4141 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4142 				if (rdev < rdev2 &&
4143 				    rdev->bdev->bd_contains ==
4144 				    rdev2->bdev->bd_contains) {
4145 					printk(KERN_WARNING
4146 					       "%s: WARNING: %s appears to be"
4147 					       " on the same physical disk as"
4148 					       " %s.\n",
4149 					       mdname(mddev),
4150 					       bdevname(rdev->bdev,b),
4151 					       bdevname(rdev2->bdev,b2));
4152 					warned = 1;
4153 				}
4154 			}
4155 
4156 		if (warned)
4157 			printk(KERN_WARNING
4158 			       "True protection against single-disk"
4159 			       " failure might be compromised.\n");
4160 	}
4161 
4162 	mddev->recovery = 0;
4163 	/* may be over-ridden by personality */
4164 	mddev->resync_max_sectors = mddev->dev_sectors;
4165 
4166 	mddev->barriers_work = 1;
4167 	mddev->ok_start_degraded = start_dirty_degraded;
4168 
4169 	if (start_readonly)
4170 		mddev->ro = 2; /* read-only, but switch on first write */
4171 
4172 	err = mddev->pers->run(mddev);
4173 	if (err)
4174 		printk(KERN_ERR "md: pers->run() failed ...\n");
4175 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4176 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4177 			  " but 'external_size' not in effect?\n", __func__);
4178 		printk(KERN_ERR
4179 		       "md: invalid array_size %llu > default size %llu\n",
4180 		       (unsigned long long)mddev->array_sectors / 2,
4181 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4182 		err = -EINVAL;
4183 		mddev->pers->stop(mddev);
4184 	}
4185 	if (err == 0 && mddev->pers->sync_request) {
4186 		err = bitmap_create(mddev);
4187 		if (err) {
4188 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4189 			       mdname(mddev), err);
4190 			mddev->pers->stop(mddev);
4191 		}
4192 	}
4193 	if (err) {
4194 		module_put(mddev->pers->owner);
4195 		mddev->pers = NULL;
4196 		bitmap_destroy(mddev);
4197 		return err;
4198 	}
4199 	if (mddev->pers->sync_request) {
4200 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4201 			printk(KERN_WARNING
4202 			       "md: cannot register extra attributes for %s\n",
4203 			       mdname(mddev));
4204 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
4205 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4206 		mddev->ro = 0;
4207 
4208  	atomic_set(&mddev->writes_pending,0);
4209 	mddev->safemode = 0;
4210 	mddev->safemode_timer.function = md_safemode_timeout;
4211 	mddev->safemode_timer.data = (unsigned long) mddev;
4212 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4213 	mddev->in_sync = 1;
4214 
4215 	list_for_each_entry(rdev, &mddev->disks, same_set)
4216 		if (rdev->raid_disk >= 0) {
4217 			char nm[20];
4218 			sprintf(nm, "rd%d", rdev->raid_disk);
4219 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
4220 				printk("md: cannot register %s for %s\n",
4221 				       nm, mdname(mddev));
4222 		}
4223 
4224 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4225 
4226 	if (mddev->flags)
4227 		md_update_sb(mddev, 0);
4228 
4229 	set_capacity(disk, mddev->array_sectors);
4230 
4231 	/* If there is a partially-recovered drive we need to
4232 	 * start recovery here.  If we leave it to md_check_recovery,
4233 	 * it will remove the drives and not do the right thing
4234 	 */
4235 	if (mddev->degraded && !mddev->sync_thread) {
4236 		int spares = 0;
4237 		list_for_each_entry(rdev, &mddev->disks, same_set)
4238 			if (rdev->raid_disk >= 0 &&
4239 			    !test_bit(In_sync, &rdev->flags) &&
4240 			    !test_bit(Faulty, &rdev->flags))
4241 				/* complete an interrupted recovery */
4242 				spares++;
4243 		if (spares && mddev->pers->sync_request) {
4244 			mddev->recovery = 0;
4245 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4246 			mddev->sync_thread = md_register_thread(md_do_sync,
4247 								mddev,
4248 								"resync");
4249 			if (!mddev->sync_thread) {
4250 				printk(KERN_ERR "%s: could not start resync"
4251 				       " thread...\n",
4252 				       mdname(mddev));
4253 				/* leave the spares where they are, it shouldn't hurt */
4254 				mddev->recovery = 0;
4255 			}
4256 		}
4257 	}
4258 	md_wakeup_thread(mddev->thread);
4259 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4260 
4261 	revalidate_disk(mddev->gendisk);
4262 	mddev->changed = 1;
4263 	md_new_event(mddev);
4264 	sysfs_notify_dirent(mddev->sysfs_state);
4265 	if (mddev->sysfs_action)
4266 		sysfs_notify_dirent(mddev->sysfs_action);
4267 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4268 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4269 	return 0;
4270 }
4271 
4272 static int restart_array(mddev_t *mddev)
4273 {
4274 	struct gendisk *disk = mddev->gendisk;
4275 
4276 	/* Complain if it has no devices */
4277 	if (list_empty(&mddev->disks))
4278 		return -ENXIO;
4279 	if (!mddev->pers)
4280 		return -EINVAL;
4281 	if (!mddev->ro)
4282 		return -EBUSY;
4283 	mddev->safemode = 0;
4284 	mddev->ro = 0;
4285 	set_disk_ro(disk, 0);
4286 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4287 		mdname(mddev));
4288 	/* Kick recovery or resync if necessary */
4289 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4290 	md_wakeup_thread(mddev->thread);
4291 	md_wakeup_thread(mddev->sync_thread);
4292 	sysfs_notify_dirent(mddev->sysfs_state);
4293 	return 0;
4294 }
4295 
4296 /* similar to deny_write_access, but accounts for our holding a reference
4297  * to the file ourselves */
4298 static int deny_bitmap_write_access(struct file * file)
4299 {
4300 	struct inode *inode = file->f_mapping->host;
4301 
4302 	spin_lock(&inode->i_lock);
4303 	if (atomic_read(&inode->i_writecount) > 1) {
4304 		spin_unlock(&inode->i_lock);
4305 		return -ETXTBSY;
4306 	}
4307 	atomic_set(&inode->i_writecount, -1);
4308 	spin_unlock(&inode->i_lock);
4309 
4310 	return 0;
4311 }
4312 
4313 static void restore_bitmap_write_access(struct file *file)
4314 {
4315 	struct inode *inode = file->f_mapping->host;
4316 
4317 	spin_lock(&inode->i_lock);
4318 	atomic_set(&inode->i_writecount, 1);
4319 	spin_unlock(&inode->i_lock);
4320 }
4321 
4322 /* mode:
4323  *   0 - completely stop and dis-assemble array
4324  *   1 - switch to readonly
4325  *   2 - stop but do not disassemble array
4326  */
4327 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4328 {
4329 	int err = 0;
4330 	struct gendisk *disk = mddev->gendisk;
4331 	mdk_rdev_t *rdev;
4332 
4333 	mutex_lock(&mddev->open_mutex);
4334 	if (atomic_read(&mddev->openers) > is_open) {
4335 		printk("md: %s still in use.\n",mdname(mddev));
4336 		err = -EBUSY;
4337 	} else if (mddev->pers) {
4338 
4339 		if (mddev->sync_thread) {
4340 			set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4341 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4342 			md_unregister_thread(mddev->sync_thread);
4343 			mddev->sync_thread = NULL;
4344 		}
4345 
4346 		del_timer_sync(&mddev->safemode_timer);
4347 
4348 		switch(mode) {
4349 		case 1: /* readonly */
4350 			err  = -ENXIO;
4351 			if (mddev->ro==1)
4352 				goto out;
4353 			mddev->ro = 1;
4354 			break;
4355 		case 0: /* disassemble */
4356 		case 2: /* stop */
4357 			bitmap_flush(mddev);
4358 			md_super_wait(mddev);
4359 			if (mddev->ro)
4360 				set_disk_ro(disk, 0);
4361 
4362 			mddev->pers->stop(mddev);
4363 			mddev->queue->merge_bvec_fn = NULL;
4364 			mddev->queue->unplug_fn = NULL;
4365 			mddev->queue->backing_dev_info.congested_fn = NULL;
4366 			module_put(mddev->pers->owner);
4367 			if (mddev->pers->sync_request)
4368 				mddev->private = &md_redundancy_group;
4369 			mddev->pers = NULL;
4370 			/* tell userspace to handle 'inactive' */
4371 			sysfs_notify_dirent(mddev->sysfs_state);
4372 
4373 			list_for_each_entry(rdev, &mddev->disks, same_set)
4374 				if (rdev->raid_disk >= 0) {
4375 					char nm[20];
4376 					sprintf(nm, "rd%d", rdev->raid_disk);
4377 					sysfs_remove_link(&mddev->kobj, nm);
4378 				}
4379 
4380 			set_capacity(disk, 0);
4381 			mddev->changed = 1;
4382 
4383 			if (mddev->ro)
4384 				mddev->ro = 0;
4385 		}
4386 		if (!mddev->in_sync || mddev->flags) {
4387 			/* mark array as shutdown cleanly */
4388 			mddev->in_sync = 1;
4389 			md_update_sb(mddev, 1);
4390 		}
4391 		if (mode == 1)
4392 			set_disk_ro(disk, 1);
4393 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4394 		err = 0;
4395 	}
4396 out:
4397 	mutex_unlock(&mddev->open_mutex);
4398 	if (err)
4399 		return err;
4400 	/*
4401 	 * Free resources if final stop
4402 	 */
4403 	if (mode == 0) {
4404 
4405 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4406 
4407 		bitmap_destroy(mddev);
4408 		if (mddev->bitmap_file) {
4409 			restore_bitmap_write_access(mddev->bitmap_file);
4410 			fput(mddev->bitmap_file);
4411 			mddev->bitmap_file = NULL;
4412 		}
4413 		mddev->bitmap_offset = 0;
4414 
4415 		/* make sure all md_delayed_delete calls have finished */
4416 		flush_scheduled_work();
4417 
4418 		export_array(mddev);
4419 
4420 		mddev->array_sectors = 0;
4421 		mddev->external_size = 0;
4422 		mddev->dev_sectors = 0;
4423 		mddev->raid_disks = 0;
4424 		mddev->recovery_cp = 0;
4425 		mddev->resync_min = 0;
4426 		mddev->resync_max = MaxSector;
4427 		mddev->reshape_position = MaxSector;
4428 		mddev->external = 0;
4429 		mddev->persistent = 0;
4430 		mddev->level = LEVEL_NONE;
4431 		mddev->clevel[0] = 0;
4432 		mddev->flags = 0;
4433 		mddev->ro = 0;
4434 		mddev->metadata_type[0] = 0;
4435 		mddev->chunk_sectors = 0;
4436 		mddev->ctime = mddev->utime = 0;
4437 		mddev->layout = 0;
4438 		mddev->max_disks = 0;
4439 		mddev->events = 0;
4440 		mddev->delta_disks = 0;
4441 		mddev->new_level = LEVEL_NONE;
4442 		mddev->new_layout = 0;
4443 		mddev->new_chunk_sectors = 0;
4444 		mddev->curr_resync = 0;
4445 		mddev->resync_mismatches = 0;
4446 		mddev->suspend_lo = mddev->suspend_hi = 0;
4447 		mddev->sync_speed_min = mddev->sync_speed_max = 0;
4448 		mddev->recovery = 0;
4449 		mddev->in_sync = 0;
4450 		mddev->changed = 0;
4451 		mddev->degraded = 0;
4452 		mddev->barriers_work = 0;
4453 		mddev->safemode = 0;
4454 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4455 		if (mddev->hold_active == UNTIL_STOP)
4456 			mddev->hold_active = 0;
4457 
4458 	} else if (mddev->pers)
4459 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
4460 			mdname(mddev));
4461 	err = 0;
4462 	blk_integrity_unregister(disk);
4463 	md_new_event(mddev);
4464 	sysfs_notify_dirent(mddev->sysfs_state);
4465 	return err;
4466 }
4467 
4468 #ifndef MODULE
4469 static void autorun_array(mddev_t *mddev)
4470 {
4471 	mdk_rdev_t *rdev;
4472 	int err;
4473 
4474 	if (list_empty(&mddev->disks))
4475 		return;
4476 
4477 	printk(KERN_INFO "md: running: ");
4478 
4479 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4480 		char b[BDEVNAME_SIZE];
4481 		printk("<%s>", bdevname(rdev->bdev,b));
4482 	}
4483 	printk("\n");
4484 
4485 	err = do_md_run(mddev);
4486 	if (err) {
4487 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4488 		do_md_stop(mddev, 0, 0);
4489 	}
4490 }
4491 
4492 /*
4493  * lets try to run arrays based on all disks that have arrived
4494  * until now. (those are in pending_raid_disks)
4495  *
4496  * the method: pick the first pending disk, collect all disks with
4497  * the same UUID, remove all from the pending list and put them into
4498  * the 'same_array' list. Then order this list based on superblock
4499  * update time (freshest comes first), kick out 'old' disks and
4500  * compare superblocks. If everything's fine then run it.
4501  *
4502  * If "unit" is allocated, then bump its reference count
4503  */
4504 static void autorun_devices(int part)
4505 {
4506 	mdk_rdev_t *rdev0, *rdev, *tmp;
4507 	mddev_t *mddev;
4508 	char b[BDEVNAME_SIZE];
4509 
4510 	printk(KERN_INFO "md: autorun ...\n");
4511 	while (!list_empty(&pending_raid_disks)) {
4512 		int unit;
4513 		dev_t dev;
4514 		LIST_HEAD(candidates);
4515 		rdev0 = list_entry(pending_raid_disks.next,
4516 					 mdk_rdev_t, same_set);
4517 
4518 		printk(KERN_INFO "md: considering %s ...\n",
4519 			bdevname(rdev0->bdev,b));
4520 		INIT_LIST_HEAD(&candidates);
4521 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4522 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4523 				printk(KERN_INFO "md:  adding %s ...\n",
4524 					bdevname(rdev->bdev,b));
4525 				list_move(&rdev->same_set, &candidates);
4526 			}
4527 		/*
4528 		 * now we have a set of devices, with all of them having
4529 		 * mostly sane superblocks. It's time to allocate the
4530 		 * mddev.
4531 		 */
4532 		if (part) {
4533 			dev = MKDEV(mdp_major,
4534 				    rdev0->preferred_minor << MdpMinorShift);
4535 			unit = MINOR(dev) >> MdpMinorShift;
4536 		} else {
4537 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4538 			unit = MINOR(dev);
4539 		}
4540 		if (rdev0->preferred_minor != unit) {
4541 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4542 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4543 			break;
4544 		}
4545 
4546 		md_probe(dev, NULL, NULL);
4547 		mddev = mddev_find(dev);
4548 		if (!mddev || !mddev->gendisk) {
4549 			if (mddev)
4550 				mddev_put(mddev);
4551 			printk(KERN_ERR
4552 				"md: cannot allocate memory for md drive.\n");
4553 			break;
4554 		}
4555 		if (mddev_lock(mddev))
4556 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4557 			       mdname(mddev));
4558 		else if (mddev->raid_disks || mddev->major_version
4559 			 || !list_empty(&mddev->disks)) {
4560 			printk(KERN_WARNING
4561 				"md: %s already running, cannot run %s\n",
4562 				mdname(mddev), bdevname(rdev0->bdev,b));
4563 			mddev_unlock(mddev);
4564 		} else {
4565 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4566 			mddev->persistent = 1;
4567 			rdev_for_each_list(rdev, tmp, &candidates) {
4568 				list_del_init(&rdev->same_set);
4569 				if (bind_rdev_to_array(rdev, mddev))
4570 					export_rdev(rdev);
4571 			}
4572 			autorun_array(mddev);
4573 			mddev_unlock(mddev);
4574 		}
4575 		/* on success, candidates will be empty, on error
4576 		 * it won't...
4577 		 */
4578 		rdev_for_each_list(rdev, tmp, &candidates) {
4579 			list_del_init(&rdev->same_set);
4580 			export_rdev(rdev);
4581 		}
4582 		mddev_put(mddev);
4583 	}
4584 	printk(KERN_INFO "md: ... autorun DONE.\n");
4585 }
4586 #endif /* !MODULE */
4587 
4588 static int get_version(void __user * arg)
4589 {
4590 	mdu_version_t ver;
4591 
4592 	ver.major = MD_MAJOR_VERSION;
4593 	ver.minor = MD_MINOR_VERSION;
4594 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4595 
4596 	if (copy_to_user(arg, &ver, sizeof(ver)))
4597 		return -EFAULT;
4598 
4599 	return 0;
4600 }
4601 
4602 static int get_array_info(mddev_t * mddev, void __user * arg)
4603 {
4604 	mdu_array_info_t info;
4605 	int nr,working,insync,failed,spare;
4606 	mdk_rdev_t *rdev;
4607 
4608 	nr=working=insync=failed=spare=0;
4609 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4610 		nr++;
4611 		if (test_bit(Faulty, &rdev->flags))
4612 			failed++;
4613 		else {
4614 			working++;
4615 			if (test_bit(In_sync, &rdev->flags))
4616 				insync++;
4617 			else
4618 				spare++;
4619 		}
4620 	}
4621 
4622 	info.major_version = mddev->major_version;
4623 	info.minor_version = mddev->minor_version;
4624 	info.patch_version = MD_PATCHLEVEL_VERSION;
4625 	info.ctime         = mddev->ctime;
4626 	info.level         = mddev->level;
4627 	info.size          = mddev->dev_sectors / 2;
4628 	if (info.size != mddev->dev_sectors / 2) /* overflow */
4629 		info.size = -1;
4630 	info.nr_disks      = nr;
4631 	info.raid_disks    = mddev->raid_disks;
4632 	info.md_minor      = mddev->md_minor;
4633 	info.not_persistent= !mddev->persistent;
4634 
4635 	info.utime         = mddev->utime;
4636 	info.state         = 0;
4637 	if (mddev->in_sync)
4638 		info.state = (1<<MD_SB_CLEAN);
4639 	if (mddev->bitmap && mddev->bitmap_offset)
4640 		info.state = (1<<MD_SB_BITMAP_PRESENT);
4641 	info.active_disks  = insync;
4642 	info.working_disks = working;
4643 	info.failed_disks  = failed;
4644 	info.spare_disks   = spare;
4645 
4646 	info.layout        = mddev->layout;
4647 	info.chunk_size    = mddev->chunk_sectors << 9;
4648 
4649 	if (copy_to_user(arg, &info, sizeof(info)))
4650 		return -EFAULT;
4651 
4652 	return 0;
4653 }
4654 
4655 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
4656 {
4657 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
4658 	char *ptr, *buf = NULL;
4659 	int err = -ENOMEM;
4660 
4661 	if (md_allow_write(mddev))
4662 		file = kmalloc(sizeof(*file), GFP_NOIO);
4663 	else
4664 		file = kmalloc(sizeof(*file), GFP_KERNEL);
4665 
4666 	if (!file)
4667 		goto out;
4668 
4669 	/* bitmap disabled, zero the first byte and copy out */
4670 	if (!mddev->bitmap || !mddev->bitmap->file) {
4671 		file->pathname[0] = '\0';
4672 		goto copy_out;
4673 	}
4674 
4675 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
4676 	if (!buf)
4677 		goto out;
4678 
4679 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
4680 	if (IS_ERR(ptr))
4681 		goto out;
4682 
4683 	strcpy(file->pathname, ptr);
4684 
4685 copy_out:
4686 	err = 0;
4687 	if (copy_to_user(arg, file, sizeof(*file)))
4688 		err = -EFAULT;
4689 out:
4690 	kfree(buf);
4691 	kfree(file);
4692 	return err;
4693 }
4694 
4695 static int get_disk_info(mddev_t * mddev, void __user * arg)
4696 {
4697 	mdu_disk_info_t info;
4698 	mdk_rdev_t *rdev;
4699 
4700 	if (copy_from_user(&info, arg, sizeof(info)))
4701 		return -EFAULT;
4702 
4703 	rdev = find_rdev_nr(mddev, info.number);
4704 	if (rdev) {
4705 		info.major = MAJOR(rdev->bdev->bd_dev);
4706 		info.minor = MINOR(rdev->bdev->bd_dev);
4707 		info.raid_disk = rdev->raid_disk;
4708 		info.state = 0;
4709 		if (test_bit(Faulty, &rdev->flags))
4710 			info.state |= (1<<MD_DISK_FAULTY);
4711 		else if (test_bit(In_sync, &rdev->flags)) {
4712 			info.state |= (1<<MD_DISK_ACTIVE);
4713 			info.state |= (1<<MD_DISK_SYNC);
4714 		}
4715 		if (test_bit(WriteMostly, &rdev->flags))
4716 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
4717 	} else {
4718 		info.major = info.minor = 0;
4719 		info.raid_disk = -1;
4720 		info.state = (1<<MD_DISK_REMOVED);
4721 	}
4722 
4723 	if (copy_to_user(arg, &info, sizeof(info)))
4724 		return -EFAULT;
4725 
4726 	return 0;
4727 }
4728 
4729 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
4730 {
4731 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4732 	mdk_rdev_t *rdev;
4733 	dev_t dev = MKDEV(info->major,info->minor);
4734 
4735 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
4736 		return -EOVERFLOW;
4737 
4738 	if (!mddev->raid_disks) {
4739 		int err;
4740 		/* expecting a device which has a superblock */
4741 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
4742 		if (IS_ERR(rdev)) {
4743 			printk(KERN_WARNING
4744 				"md: md_import_device returned %ld\n",
4745 				PTR_ERR(rdev));
4746 			return PTR_ERR(rdev);
4747 		}
4748 		if (!list_empty(&mddev->disks)) {
4749 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
4750 							mdk_rdev_t, same_set);
4751 			err = super_types[mddev->major_version]
4752 				.load_super(rdev, rdev0, mddev->minor_version);
4753 			if (err < 0) {
4754 				printk(KERN_WARNING
4755 					"md: %s has different UUID to %s\n",
4756 					bdevname(rdev->bdev,b),
4757 					bdevname(rdev0->bdev,b2));
4758 				export_rdev(rdev);
4759 				return -EINVAL;
4760 			}
4761 		}
4762 		err = bind_rdev_to_array(rdev, mddev);
4763 		if (err)
4764 			export_rdev(rdev);
4765 		return err;
4766 	}
4767 
4768 	/*
4769 	 * add_new_disk can be used once the array is assembled
4770 	 * to add "hot spares".  They must already have a superblock
4771 	 * written
4772 	 */
4773 	if (mddev->pers) {
4774 		int err;
4775 		if (!mddev->pers->hot_add_disk) {
4776 			printk(KERN_WARNING
4777 				"%s: personality does not support diskops!\n",
4778 			       mdname(mddev));
4779 			return -EINVAL;
4780 		}
4781 		if (mddev->persistent)
4782 			rdev = md_import_device(dev, mddev->major_version,
4783 						mddev->minor_version);
4784 		else
4785 			rdev = md_import_device(dev, -1, -1);
4786 		if (IS_ERR(rdev)) {
4787 			printk(KERN_WARNING
4788 				"md: md_import_device returned %ld\n",
4789 				PTR_ERR(rdev));
4790 			return PTR_ERR(rdev);
4791 		}
4792 		/* set save_raid_disk if appropriate */
4793 		if (!mddev->persistent) {
4794 			if (info->state & (1<<MD_DISK_SYNC)  &&
4795 			    info->raid_disk < mddev->raid_disks)
4796 				rdev->raid_disk = info->raid_disk;
4797 			else
4798 				rdev->raid_disk = -1;
4799 		} else
4800 			super_types[mddev->major_version].
4801 				validate_super(mddev, rdev);
4802 		rdev->saved_raid_disk = rdev->raid_disk;
4803 
4804 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
4805 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4806 			set_bit(WriteMostly, &rdev->flags);
4807 		else
4808 			clear_bit(WriteMostly, &rdev->flags);
4809 
4810 		rdev->raid_disk = -1;
4811 		err = bind_rdev_to_array(rdev, mddev);
4812 		if (!err && !mddev->pers->hot_remove_disk) {
4813 			/* If there is hot_add_disk but no hot_remove_disk
4814 			 * then added disks for geometry changes,
4815 			 * and should be added immediately.
4816 			 */
4817 			super_types[mddev->major_version].
4818 				validate_super(mddev, rdev);
4819 			err = mddev->pers->hot_add_disk(mddev, rdev);
4820 			if (err)
4821 				unbind_rdev_from_array(rdev);
4822 		}
4823 		if (err)
4824 			export_rdev(rdev);
4825 		else
4826 			sysfs_notify_dirent(rdev->sysfs_state);
4827 
4828 		md_update_sb(mddev, 1);
4829 		if (mddev->degraded)
4830 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4831 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4832 		md_wakeup_thread(mddev->thread);
4833 		return err;
4834 	}
4835 
4836 	/* otherwise, add_new_disk is only allowed
4837 	 * for major_version==0 superblocks
4838 	 */
4839 	if (mddev->major_version != 0) {
4840 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
4841 		       mdname(mddev));
4842 		return -EINVAL;
4843 	}
4844 
4845 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
4846 		int err;
4847 		rdev = md_import_device(dev, -1, 0);
4848 		if (IS_ERR(rdev)) {
4849 			printk(KERN_WARNING
4850 				"md: error, md_import_device() returned %ld\n",
4851 				PTR_ERR(rdev));
4852 			return PTR_ERR(rdev);
4853 		}
4854 		rdev->desc_nr = info->number;
4855 		if (info->raid_disk < mddev->raid_disks)
4856 			rdev->raid_disk = info->raid_disk;
4857 		else
4858 			rdev->raid_disk = -1;
4859 
4860 		if (rdev->raid_disk < mddev->raid_disks)
4861 			if (info->state & (1<<MD_DISK_SYNC))
4862 				set_bit(In_sync, &rdev->flags);
4863 
4864 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4865 			set_bit(WriteMostly, &rdev->flags);
4866 
4867 		if (!mddev->persistent) {
4868 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
4869 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4870 		} else
4871 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4872 		rdev->sectors = rdev->sb_start;
4873 
4874 		err = bind_rdev_to_array(rdev, mddev);
4875 		if (err) {
4876 			export_rdev(rdev);
4877 			return err;
4878 		}
4879 	}
4880 
4881 	return 0;
4882 }
4883 
4884 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
4885 {
4886 	char b[BDEVNAME_SIZE];
4887 	mdk_rdev_t *rdev;
4888 
4889 	rdev = find_rdev(mddev, dev);
4890 	if (!rdev)
4891 		return -ENXIO;
4892 
4893 	if (rdev->raid_disk >= 0)
4894 		goto busy;
4895 
4896 	kick_rdev_from_array(rdev);
4897 	md_update_sb(mddev, 1);
4898 	md_new_event(mddev);
4899 
4900 	return 0;
4901 busy:
4902 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
4903 		bdevname(rdev->bdev,b), mdname(mddev));
4904 	return -EBUSY;
4905 }
4906 
4907 static int hot_add_disk(mddev_t * mddev, dev_t dev)
4908 {
4909 	char b[BDEVNAME_SIZE];
4910 	int err;
4911 	mdk_rdev_t *rdev;
4912 
4913 	if (!mddev->pers)
4914 		return -ENODEV;
4915 
4916 	if (mddev->major_version != 0) {
4917 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
4918 			" version-0 superblocks.\n",
4919 			mdname(mddev));
4920 		return -EINVAL;
4921 	}
4922 	if (!mddev->pers->hot_add_disk) {
4923 		printk(KERN_WARNING
4924 			"%s: personality does not support diskops!\n",
4925 			mdname(mddev));
4926 		return -EINVAL;
4927 	}
4928 
4929 	rdev = md_import_device(dev, -1, 0);
4930 	if (IS_ERR(rdev)) {
4931 		printk(KERN_WARNING
4932 			"md: error, md_import_device() returned %ld\n",
4933 			PTR_ERR(rdev));
4934 		return -EINVAL;
4935 	}
4936 
4937 	if (mddev->persistent)
4938 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4939 	else
4940 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4941 
4942 	rdev->sectors = rdev->sb_start;
4943 
4944 	if (test_bit(Faulty, &rdev->flags)) {
4945 		printk(KERN_WARNING
4946 			"md: can not hot-add faulty %s disk to %s!\n",
4947 			bdevname(rdev->bdev,b), mdname(mddev));
4948 		err = -EINVAL;
4949 		goto abort_export;
4950 	}
4951 	clear_bit(In_sync, &rdev->flags);
4952 	rdev->desc_nr = -1;
4953 	rdev->saved_raid_disk = -1;
4954 	err = bind_rdev_to_array(rdev, mddev);
4955 	if (err)
4956 		goto abort_export;
4957 
4958 	/*
4959 	 * The rest should better be atomic, we can have disk failures
4960 	 * noticed in interrupt contexts ...
4961 	 */
4962 
4963 	rdev->raid_disk = -1;
4964 
4965 	md_update_sb(mddev, 1);
4966 
4967 	/*
4968 	 * Kick recovery, maybe this spare has to be added to the
4969 	 * array immediately.
4970 	 */
4971 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4972 	md_wakeup_thread(mddev->thread);
4973 	md_new_event(mddev);
4974 	return 0;
4975 
4976 abort_export:
4977 	export_rdev(rdev);
4978 	return err;
4979 }
4980 
4981 static int set_bitmap_file(mddev_t *mddev, int fd)
4982 {
4983 	int err;
4984 
4985 	if (mddev->pers) {
4986 		if (!mddev->pers->quiesce)
4987 			return -EBUSY;
4988 		if (mddev->recovery || mddev->sync_thread)
4989 			return -EBUSY;
4990 		/* we should be able to change the bitmap.. */
4991 	}
4992 
4993 
4994 	if (fd >= 0) {
4995 		if (mddev->bitmap)
4996 			return -EEXIST; /* cannot add when bitmap is present */
4997 		mddev->bitmap_file = fget(fd);
4998 
4999 		if (mddev->bitmap_file == NULL) {
5000 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5001 			       mdname(mddev));
5002 			return -EBADF;
5003 		}
5004 
5005 		err = deny_bitmap_write_access(mddev->bitmap_file);
5006 		if (err) {
5007 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5008 			       mdname(mddev));
5009 			fput(mddev->bitmap_file);
5010 			mddev->bitmap_file = NULL;
5011 			return err;
5012 		}
5013 		mddev->bitmap_offset = 0; /* file overrides offset */
5014 	} else if (mddev->bitmap == NULL)
5015 		return -ENOENT; /* cannot remove what isn't there */
5016 	err = 0;
5017 	if (mddev->pers) {
5018 		mddev->pers->quiesce(mddev, 1);
5019 		if (fd >= 0)
5020 			err = bitmap_create(mddev);
5021 		if (fd < 0 || err) {
5022 			bitmap_destroy(mddev);
5023 			fd = -1; /* make sure to put the file */
5024 		}
5025 		mddev->pers->quiesce(mddev, 0);
5026 	}
5027 	if (fd < 0) {
5028 		if (mddev->bitmap_file) {
5029 			restore_bitmap_write_access(mddev->bitmap_file);
5030 			fput(mddev->bitmap_file);
5031 		}
5032 		mddev->bitmap_file = NULL;
5033 	}
5034 
5035 	return err;
5036 }
5037 
5038 /*
5039  * set_array_info is used two different ways
5040  * The original usage is when creating a new array.
5041  * In this usage, raid_disks is > 0 and it together with
5042  *  level, size, not_persistent,layout,chunksize determine the
5043  *  shape of the array.
5044  *  This will always create an array with a type-0.90.0 superblock.
5045  * The newer usage is when assembling an array.
5046  *  In this case raid_disks will be 0, and the major_version field is
5047  *  use to determine which style super-blocks are to be found on the devices.
5048  *  The minor and patch _version numbers are also kept incase the
5049  *  super_block handler wishes to interpret them.
5050  */
5051 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5052 {
5053 
5054 	if (info->raid_disks == 0) {
5055 		/* just setting version number for superblock loading */
5056 		if (info->major_version < 0 ||
5057 		    info->major_version >= ARRAY_SIZE(super_types) ||
5058 		    super_types[info->major_version].name == NULL) {
5059 			/* maybe try to auto-load a module? */
5060 			printk(KERN_INFO
5061 				"md: superblock version %d not known\n",
5062 				info->major_version);
5063 			return -EINVAL;
5064 		}
5065 		mddev->major_version = info->major_version;
5066 		mddev->minor_version = info->minor_version;
5067 		mddev->patch_version = info->patch_version;
5068 		mddev->persistent = !info->not_persistent;
5069 		return 0;
5070 	}
5071 	mddev->major_version = MD_MAJOR_VERSION;
5072 	mddev->minor_version = MD_MINOR_VERSION;
5073 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5074 	mddev->ctime         = get_seconds();
5075 
5076 	mddev->level         = info->level;
5077 	mddev->clevel[0]     = 0;
5078 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5079 	mddev->raid_disks    = info->raid_disks;
5080 	/* don't set md_minor, it is determined by which /dev/md* was
5081 	 * openned
5082 	 */
5083 	if (info->state & (1<<MD_SB_CLEAN))
5084 		mddev->recovery_cp = MaxSector;
5085 	else
5086 		mddev->recovery_cp = 0;
5087 	mddev->persistent    = ! info->not_persistent;
5088 	mddev->external	     = 0;
5089 
5090 	mddev->layout        = info->layout;
5091 	mddev->chunk_sectors = info->chunk_size >> 9;
5092 
5093 	mddev->max_disks     = MD_SB_DISKS;
5094 
5095 	if (mddev->persistent)
5096 		mddev->flags         = 0;
5097 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5098 
5099 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
5100 	mddev->bitmap_offset = 0;
5101 
5102 	mddev->reshape_position = MaxSector;
5103 
5104 	/*
5105 	 * Generate a 128 bit UUID
5106 	 */
5107 	get_random_bytes(mddev->uuid, 16);
5108 
5109 	mddev->new_level = mddev->level;
5110 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5111 	mddev->new_layout = mddev->layout;
5112 	mddev->delta_disks = 0;
5113 
5114 	return 0;
5115 }
5116 
5117 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5118 {
5119 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5120 
5121 	if (mddev->external_size)
5122 		return;
5123 
5124 	mddev->array_sectors = array_sectors;
5125 }
5126 EXPORT_SYMBOL(md_set_array_sectors);
5127 
5128 static int update_size(mddev_t *mddev, sector_t num_sectors)
5129 {
5130 	mdk_rdev_t *rdev;
5131 	int rv;
5132 	int fit = (num_sectors == 0);
5133 
5134 	if (mddev->pers->resize == NULL)
5135 		return -EINVAL;
5136 	/* The "num_sectors" is the number of sectors of each device that
5137 	 * is used.  This can only make sense for arrays with redundancy.
5138 	 * linear and raid0 always use whatever space is available. We can only
5139 	 * consider changing this number if no resync or reconstruction is
5140 	 * happening, and if the new size is acceptable. It must fit before the
5141 	 * sb_start or, if that is <data_offset, it must fit before the size
5142 	 * of each device.  If num_sectors is zero, we find the largest size
5143 	 * that fits.
5144 
5145 	 */
5146 	if (mddev->sync_thread)
5147 		return -EBUSY;
5148 	if (mddev->bitmap)
5149 		/* Sorry, cannot grow a bitmap yet, just remove it,
5150 		 * grow, and re-add.
5151 		 */
5152 		return -EBUSY;
5153 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5154 		sector_t avail = rdev->sectors;
5155 
5156 		if (fit && (num_sectors == 0 || num_sectors > avail))
5157 			num_sectors = avail;
5158 		if (avail < num_sectors)
5159 			return -ENOSPC;
5160 	}
5161 	rv = mddev->pers->resize(mddev, num_sectors);
5162 	if (!rv)
5163 		revalidate_disk(mddev->gendisk);
5164 	return rv;
5165 }
5166 
5167 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5168 {
5169 	int rv;
5170 	/* change the number of raid disks */
5171 	if (mddev->pers->check_reshape == NULL)
5172 		return -EINVAL;
5173 	if (raid_disks <= 0 ||
5174 	    raid_disks >= mddev->max_disks)
5175 		return -EINVAL;
5176 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5177 		return -EBUSY;
5178 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5179 
5180 	rv = mddev->pers->check_reshape(mddev);
5181 	return rv;
5182 }
5183 
5184 
5185 /*
5186  * update_array_info is used to change the configuration of an
5187  * on-line array.
5188  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5189  * fields in the info are checked against the array.
5190  * Any differences that cannot be handled will cause an error.
5191  * Normally, only one change can be managed at a time.
5192  */
5193 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5194 {
5195 	int rv = 0;
5196 	int cnt = 0;
5197 	int state = 0;
5198 
5199 	/* calculate expected state,ignoring low bits */
5200 	if (mddev->bitmap && mddev->bitmap_offset)
5201 		state |= (1 << MD_SB_BITMAP_PRESENT);
5202 
5203 	if (mddev->major_version != info->major_version ||
5204 	    mddev->minor_version != info->minor_version ||
5205 /*	    mddev->patch_version != info->patch_version || */
5206 	    mddev->ctime         != info->ctime         ||
5207 	    mddev->level         != info->level         ||
5208 /*	    mddev->layout        != info->layout        || */
5209 	    !mddev->persistent	 != info->not_persistent||
5210 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5211 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5212 	    ((state^info->state) & 0xfffffe00)
5213 		)
5214 		return -EINVAL;
5215 	/* Check there is only one change */
5216 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5217 		cnt++;
5218 	if (mddev->raid_disks != info->raid_disks)
5219 		cnt++;
5220 	if (mddev->layout != info->layout)
5221 		cnt++;
5222 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5223 		cnt++;
5224 	if (cnt == 0)
5225 		return 0;
5226 	if (cnt > 1)
5227 		return -EINVAL;
5228 
5229 	if (mddev->layout != info->layout) {
5230 		/* Change layout
5231 		 * we don't need to do anything at the md level, the
5232 		 * personality will take care of it all.
5233 		 */
5234 		if (mddev->pers->check_reshape == NULL)
5235 			return -EINVAL;
5236 		else {
5237 			mddev->new_layout = info->layout;
5238 			rv = mddev->pers->check_reshape(mddev);
5239 			if (rv)
5240 				mddev->new_layout = mddev->layout;
5241 			return rv;
5242 		}
5243 	}
5244 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5245 		rv = update_size(mddev, (sector_t)info->size * 2);
5246 
5247 	if (mddev->raid_disks    != info->raid_disks)
5248 		rv = update_raid_disks(mddev, info->raid_disks);
5249 
5250 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5251 		if (mddev->pers->quiesce == NULL)
5252 			return -EINVAL;
5253 		if (mddev->recovery || mddev->sync_thread)
5254 			return -EBUSY;
5255 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5256 			/* add the bitmap */
5257 			if (mddev->bitmap)
5258 				return -EEXIST;
5259 			if (mddev->default_bitmap_offset == 0)
5260 				return -EINVAL;
5261 			mddev->bitmap_offset = mddev->default_bitmap_offset;
5262 			mddev->pers->quiesce(mddev, 1);
5263 			rv = bitmap_create(mddev);
5264 			if (rv)
5265 				bitmap_destroy(mddev);
5266 			mddev->pers->quiesce(mddev, 0);
5267 		} else {
5268 			/* remove the bitmap */
5269 			if (!mddev->bitmap)
5270 				return -ENOENT;
5271 			if (mddev->bitmap->file)
5272 				return -EINVAL;
5273 			mddev->pers->quiesce(mddev, 1);
5274 			bitmap_destroy(mddev);
5275 			mddev->pers->quiesce(mddev, 0);
5276 			mddev->bitmap_offset = 0;
5277 		}
5278 	}
5279 	md_update_sb(mddev, 1);
5280 	return rv;
5281 }
5282 
5283 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5284 {
5285 	mdk_rdev_t *rdev;
5286 
5287 	if (mddev->pers == NULL)
5288 		return -ENODEV;
5289 
5290 	rdev = find_rdev(mddev, dev);
5291 	if (!rdev)
5292 		return -ENODEV;
5293 
5294 	md_error(mddev, rdev);
5295 	return 0;
5296 }
5297 
5298 /*
5299  * We have a problem here : there is no easy way to give a CHS
5300  * virtual geometry. We currently pretend that we have a 2 heads
5301  * 4 sectors (with a BIG number of cylinders...). This drives
5302  * dosfs just mad... ;-)
5303  */
5304 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5305 {
5306 	mddev_t *mddev = bdev->bd_disk->private_data;
5307 
5308 	geo->heads = 2;
5309 	geo->sectors = 4;
5310 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
5311 	return 0;
5312 }
5313 
5314 static int md_ioctl(struct block_device *bdev, fmode_t mode,
5315 			unsigned int cmd, unsigned long arg)
5316 {
5317 	int err = 0;
5318 	void __user *argp = (void __user *)arg;
5319 	mddev_t *mddev = NULL;
5320 
5321 	if (!capable(CAP_SYS_ADMIN))
5322 		return -EACCES;
5323 
5324 	/*
5325 	 * Commands dealing with the RAID driver but not any
5326 	 * particular array:
5327 	 */
5328 	switch (cmd)
5329 	{
5330 		case RAID_VERSION:
5331 			err = get_version(argp);
5332 			goto done;
5333 
5334 		case PRINT_RAID_DEBUG:
5335 			err = 0;
5336 			md_print_devices();
5337 			goto done;
5338 
5339 #ifndef MODULE
5340 		case RAID_AUTORUN:
5341 			err = 0;
5342 			autostart_arrays(arg);
5343 			goto done;
5344 #endif
5345 		default:;
5346 	}
5347 
5348 	/*
5349 	 * Commands creating/starting a new array:
5350 	 */
5351 
5352 	mddev = bdev->bd_disk->private_data;
5353 
5354 	if (!mddev) {
5355 		BUG();
5356 		goto abort;
5357 	}
5358 
5359 	err = mddev_lock(mddev);
5360 	if (err) {
5361 		printk(KERN_INFO
5362 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5363 			err, cmd);
5364 		goto abort;
5365 	}
5366 
5367 	switch (cmd)
5368 	{
5369 		case SET_ARRAY_INFO:
5370 			{
5371 				mdu_array_info_t info;
5372 				if (!arg)
5373 					memset(&info, 0, sizeof(info));
5374 				else if (copy_from_user(&info, argp, sizeof(info))) {
5375 					err = -EFAULT;
5376 					goto abort_unlock;
5377 				}
5378 				if (mddev->pers) {
5379 					err = update_array_info(mddev, &info);
5380 					if (err) {
5381 						printk(KERN_WARNING "md: couldn't update"
5382 						       " array info. %d\n", err);
5383 						goto abort_unlock;
5384 					}
5385 					goto done_unlock;
5386 				}
5387 				if (!list_empty(&mddev->disks)) {
5388 					printk(KERN_WARNING
5389 					       "md: array %s already has disks!\n",
5390 					       mdname(mddev));
5391 					err = -EBUSY;
5392 					goto abort_unlock;
5393 				}
5394 				if (mddev->raid_disks) {
5395 					printk(KERN_WARNING
5396 					       "md: array %s already initialised!\n",
5397 					       mdname(mddev));
5398 					err = -EBUSY;
5399 					goto abort_unlock;
5400 				}
5401 				err = set_array_info(mddev, &info);
5402 				if (err) {
5403 					printk(KERN_WARNING "md: couldn't set"
5404 					       " array info. %d\n", err);
5405 					goto abort_unlock;
5406 				}
5407 			}
5408 			goto done_unlock;
5409 
5410 		default:;
5411 	}
5412 
5413 	/*
5414 	 * Commands querying/configuring an existing array:
5415 	 */
5416 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5417 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5418 	if ((!mddev->raid_disks && !mddev->external)
5419 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5420 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5421 	    && cmd != GET_BITMAP_FILE) {
5422 		err = -ENODEV;
5423 		goto abort_unlock;
5424 	}
5425 
5426 	/*
5427 	 * Commands even a read-only array can execute:
5428 	 */
5429 	switch (cmd)
5430 	{
5431 		case GET_ARRAY_INFO:
5432 			err = get_array_info(mddev, argp);
5433 			goto done_unlock;
5434 
5435 		case GET_BITMAP_FILE:
5436 			err = get_bitmap_file(mddev, argp);
5437 			goto done_unlock;
5438 
5439 		case GET_DISK_INFO:
5440 			err = get_disk_info(mddev, argp);
5441 			goto done_unlock;
5442 
5443 		case RESTART_ARRAY_RW:
5444 			err = restart_array(mddev);
5445 			goto done_unlock;
5446 
5447 		case STOP_ARRAY:
5448 			err = do_md_stop(mddev, 0, 1);
5449 			goto done_unlock;
5450 
5451 		case STOP_ARRAY_RO:
5452 			err = do_md_stop(mddev, 1, 1);
5453 			goto done_unlock;
5454 
5455 	}
5456 
5457 	/*
5458 	 * The remaining ioctls are changing the state of the
5459 	 * superblock, so we do not allow them on read-only arrays.
5460 	 * However non-MD ioctls (e.g. get-size) will still come through
5461 	 * here and hit the 'default' below, so only disallow
5462 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5463 	 */
5464 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5465 		if (mddev->ro == 2) {
5466 			mddev->ro = 0;
5467 			sysfs_notify_dirent(mddev->sysfs_state);
5468 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5469 			md_wakeup_thread(mddev->thread);
5470 		} else {
5471 			err = -EROFS;
5472 			goto abort_unlock;
5473 		}
5474 	}
5475 
5476 	switch (cmd)
5477 	{
5478 		case ADD_NEW_DISK:
5479 		{
5480 			mdu_disk_info_t info;
5481 			if (copy_from_user(&info, argp, sizeof(info)))
5482 				err = -EFAULT;
5483 			else
5484 				err = add_new_disk(mddev, &info);
5485 			goto done_unlock;
5486 		}
5487 
5488 		case HOT_REMOVE_DISK:
5489 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5490 			goto done_unlock;
5491 
5492 		case HOT_ADD_DISK:
5493 			err = hot_add_disk(mddev, new_decode_dev(arg));
5494 			goto done_unlock;
5495 
5496 		case SET_DISK_FAULTY:
5497 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5498 			goto done_unlock;
5499 
5500 		case RUN_ARRAY:
5501 			err = do_md_run(mddev);
5502 			goto done_unlock;
5503 
5504 		case SET_BITMAP_FILE:
5505 			err = set_bitmap_file(mddev, (int)arg);
5506 			goto done_unlock;
5507 
5508 		default:
5509 			err = -EINVAL;
5510 			goto abort_unlock;
5511 	}
5512 
5513 done_unlock:
5514 abort_unlock:
5515 	if (mddev->hold_active == UNTIL_IOCTL &&
5516 	    err != -EINVAL)
5517 		mddev->hold_active = 0;
5518 	mddev_unlock(mddev);
5519 
5520 	return err;
5521 done:
5522 	if (err)
5523 		MD_BUG();
5524 abort:
5525 	return err;
5526 }
5527 
5528 static int md_open(struct block_device *bdev, fmode_t mode)
5529 {
5530 	/*
5531 	 * Succeed if we can lock the mddev, which confirms that
5532 	 * it isn't being stopped right now.
5533 	 */
5534 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5535 	int err;
5536 
5537 	if (mddev->gendisk != bdev->bd_disk) {
5538 		/* we are racing with mddev_put which is discarding this
5539 		 * bd_disk.
5540 		 */
5541 		mddev_put(mddev);
5542 		/* Wait until bdev->bd_disk is definitely gone */
5543 		flush_scheduled_work();
5544 		/* Then retry the open from the top */
5545 		return -ERESTARTSYS;
5546 	}
5547 	BUG_ON(mddev != bdev->bd_disk->private_data);
5548 
5549 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
5550 		goto out;
5551 
5552 	err = 0;
5553 	atomic_inc(&mddev->openers);
5554 	mutex_unlock(&mddev->open_mutex);
5555 
5556 	check_disk_change(bdev);
5557  out:
5558 	return err;
5559 }
5560 
5561 static int md_release(struct gendisk *disk, fmode_t mode)
5562 {
5563  	mddev_t *mddev = disk->private_data;
5564 
5565 	BUG_ON(!mddev);
5566 	atomic_dec(&mddev->openers);
5567 	mddev_put(mddev);
5568 
5569 	return 0;
5570 }
5571 
5572 static int md_media_changed(struct gendisk *disk)
5573 {
5574 	mddev_t *mddev = disk->private_data;
5575 
5576 	return mddev->changed;
5577 }
5578 
5579 static int md_revalidate(struct gendisk *disk)
5580 {
5581 	mddev_t *mddev = disk->private_data;
5582 
5583 	mddev->changed = 0;
5584 	return 0;
5585 }
5586 static const struct block_device_operations md_fops =
5587 {
5588 	.owner		= THIS_MODULE,
5589 	.open		= md_open,
5590 	.release	= md_release,
5591 	.ioctl		= md_ioctl,
5592 	.getgeo		= md_getgeo,
5593 	.media_changed	= md_media_changed,
5594 	.revalidate_disk= md_revalidate,
5595 };
5596 
5597 static int md_thread(void * arg)
5598 {
5599 	mdk_thread_t *thread = arg;
5600 
5601 	/*
5602 	 * md_thread is a 'system-thread', it's priority should be very
5603 	 * high. We avoid resource deadlocks individually in each
5604 	 * raid personality. (RAID5 does preallocation) We also use RR and
5605 	 * the very same RT priority as kswapd, thus we will never get
5606 	 * into a priority inversion deadlock.
5607 	 *
5608 	 * we definitely have to have equal or higher priority than
5609 	 * bdflush, otherwise bdflush will deadlock if there are too
5610 	 * many dirty RAID5 blocks.
5611 	 */
5612 
5613 	allow_signal(SIGKILL);
5614 	while (!kthread_should_stop()) {
5615 
5616 		/* We need to wait INTERRUPTIBLE so that
5617 		 * we don't add to the load-average.
5618 		 * That means we need to be sure no signals are
5619 		 * pending
5620 		 */
5621 		if (signal_pending(current))
5622 			flush_signals(current);
5623 
5624 		wait_event_interruptible_timeout
5625 			(thread->wqueue,
5626 			 test_bit(THREAD_WAKEUP, &thread->flags)
5627 			 || kthread_should_stop(),
5628 			 thread->timeout);
5629 
5630 		clear_bit(THREAD_WAKEUP, &thread->flags);
5631 
5632 		thread->run(thread->mddev);
5633 	}
5634 
5635 	return 0;
5636 }
5637 
5638 void md_wakeup_thread(mdk_thread_t *thread)
5639 {
5640 	if (thread) {
5641 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
5642 		set_bit(THREAD_WAKEUP, &thread->flags);
5643 		wake_up(&thread->wqueue);
5644 	}
5645 }
5646 
5647 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
5648 				 const char *name)
5649 {
5650 	mdk_thread_t *thread;
5651 
5652 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
5653 	if (!thread)
5654 		return NULL;
5655 
5656 	init_waitqueue_head(&thread->wqueue);
5657 
5658 	thread->run = run;
5659 	thread->mddev = mddev;
5660 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
5661 	thread->tsk = kthread_run(md_thread, thread,
5662 				  "%s_%s",
5663 				  mdname(thread->mddev),
5664 				  name ?: mddev->pers->name);
5665 	if (IS_ERR(thread->tsk)) {
5666 		kfree(thread);
5667 		return NULL;
5668 	}
5669 	return thread;
5670 }
5671 
5672 void md_unregister_thread(mdk_thread_t *thread)
5673 {
5674 	if (!thread)
5675 		return;
5676 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
5677 
5678 	kthread_stop(thread->tsk);
5679 	kfree(thread);
5680 }
5681 
5682 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
5683 {
5684 	if (!mddev) {
5685 		MD_BUG();
5686 		return;
5687 	}
5688 
5689 	if (!rdev || test_bit(Faulty, &rdev->flags))
5690 		return;
5691 
5692 	if (mddev->external)
5693 		set_bit(Blocked, &rdev->flags);
5694 /*
5695 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
5696 		mdname(mddev),
5697 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
5698 		__builtin_return_address(0),__builtin_return_address(1),
5699 		__builtin_return_address(2),__builtin_return_address(3));
5700 */
5701 	if (!mddev->pers)
5702 		return;
5703 	if (!mddev->pers->error_handler)
5704 		return;
5705 	mddev->pers->error_handler(mddev,rdev);
5706 	if (mddev->degraded)
5707 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5708 	set_bit(StateChanged, &rdev->flags);
5709 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5710 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5711 	md_wakeup_thread(mddev->thread);
5712 	md_new_event_inintr(mddev);
5713 }
5714 
5715 /* seq_file implementation /proc/mdstat */
5716 
5717 static void status_unused(struct seq_file *seq)
5718 {
5719 	int i = 0;
5720 	mdk_rdev_t *rdev;
5721 
5722 	seq_printf(seq, "unused devices: ");
5723 
5724 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
5725 		char b[BDEVNAME_SIZE];
5726 		i++;
5727 		seq_printf(seq, "%s ",
5728 			      bdevname(rdev->bdev,b));
5729 	}
5730 	if (!i)
5731 		seq_printf(seq, "<none>");
5732 
5733 	seq_printf(seq, "\n");
5734 }
5735 
5736 
5737 static void status_resync(struct seq_file *seq, mddev_t * mddev)
5738 {
5739 	sector_t max_sectors, resync, res;
5740 	unsigned long dt, db;
5741 	sector_t rt;
5742 	int scale;
5743 	unsigned int per_milli;
5744 
5745 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
5746 
5747 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
5748 		max_sectors = mddev->resync_max_sectors;
5749 	else
5750 		max_sectors = mddev->dev_sectors;
5751 
5752 	/*
5753 	 * Should not happen.
5754 	 */
5755 	if (!max_sectors) {
5756 		MD_BUG();
5757 		return;
5758 	}
5759 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
5760 	 * in a sector_t, and (max_sectors>>scale) will fit in a
5761 	 * u32, as those are the requirements for sector_div.
5762 	 * Thus 'scale' must be at least 10
5763 	 */
5764 	scale = 10;
5765 	if (sizeof(sector_t) > sizeof(unsigned long)) {
5766 		while ( max_sectors/2 > (1ULL<<(scale+32)))
5767 			scale++;
5768 	}
5769 	res = (resync>>scale)*1000;
5770 	sector_div(res, (u32)((max_sectors>>scale)+1));
5771 
5772 	per_milli = res;
5773 	{
5774 		int i, x = per_milli/50, y = 20-x;
5775 		seq_printf(seq, "[");
5776 		for (i = 0; i < x; i++)
5777 			seq_printf(seq, "=");
5778 		seq_printf(seq, ">");
5779 		for (i = 0; i < y; i++)
5780 			seq_printf(seq, ".");
5781 		seq_printf(seq, "] ");
5782 	}
5783 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
5784 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
5785 		    "reshape" :
5786 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
5787 		     "check" :
5788 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
5789 		      "resync" : "recovery"))),
5790 		   per_milli/10, per_milli % 10,
5791 		   (unsigned long long) resync/2,
5792 		   (unsigned long long) max_sectors/2);
5793 
5794 	/*
5795 	 * dt: time from mark until now
5796 	 * db: blocks written from mark until now
5797 	 * rt: remaining time
5798 	 *
5799 	 * rt is a sector_t, so could be 32bit or 64bit.
5800 	 * So we divide before multiply in case it is 32bit and close
5801 	 * to the limit.
5802 	 * We scale the divisor (db) by 32 to avoid loosing precision
5803 	 * near the end of resync when the number of remaining sectors
5804 	 * is close to 'db'.
5805 	 * We then divide rt by 32 after multiplying by db to compensate.
5806 	 * The '+1' avoids division by zero if db is very small.
5807 	 */
5808 	dt = ((jiffies - mddev->resync_mark) / HZ);
5809 	if (!dt) dt++;
5810 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
5811 		- mddev->resync_mark_cnt;
5812 
5813 	rt = max_sectors - resync;    /* number of remaining sectors */
5814 	sector_div(rt, db/32+1);
5815 	rt *= dt;
5816 	rt >>= 5;
5817 
5818 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
5819 		   ((unsigned long)rt % 60)/6);
5820 
5821 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
5822 }
5823 
5824 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
5825 {
5826 	struct list_head *tmp;
5827 	loff_t l = *pos;
5828 	mddev_t *mddev;
5829 
5830 	if (l >= 0x10000)
5831 		return NULL;
5832 	if (!l--)
5833 		/* header */
5834 		return (void*)1;
5835 
5836 	spin_lock(&all_mddevs_lock);
5837 	list_for_each(tmp,&all_mddevs)
5838 		if (!l--) {
5839 			mddev = list_entry(tmp, mddev_t, all_mddevs);
5840 			mddev_get(mddev);
5841 			spin_unlock(&all_mddevs_lock);
5842 			return mddev;
5843 		}
5844 	spin_unlock(&all_mddevs_lock);
5845 	if (!l--)
5846 		return (void*)2;/* tail */
5847 	return NULL;
5848 }
5849 
5850 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
5851 {
5852 	struct list_head *tmp;
5853 	mddev_t *next_mddev, *mddev = v;
5854 
5855 	++*pos;
5856 	if (v == (void*)2)
5857 		return NULL;
5858 
5859 	spin_lock(&all_mddevs_lock);
5860 	if (v == (void*)1)
5861 		tmp = all_mddevs.next;
5862 	else
5863 		tmp = mddev->all_mddevs.next;
5864 	if (tmp != &all_mddevs)
5865 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
5866 	else {
5867 		next_mddev = (void*)2;
5868 		*pos = 0x10000;
5869 	}
5870 	spin_unlock(&all_mddevs_lock);
5871 
5872 	if (v != (void*)1)
5873 		mddev_put(mddev);
5874 	return next_mddev;
5875 
5876 }
5877 
5878 static void md_seq_stop(struct seq_file *seq, void *v)
5879 {
5880 	mddev_t *mddev = v;
5881 
5882 	if (mddev && v != (void*)1 && v != (void*)2)
5883 		mddev_put(mddev);
5884 }
5885 
5886 struct mdstat_info {
5887 	int event;
5888 };
5889 
5890 static int md_seq_show(struct seq_file *seq, void *v)
5891 {
5892 	mddev_t *mddev = v;
5893 	sector_t sectors;
5894 	mdk_rdev_t *rdev;
5895 	struct mdstat_info *mi = seq->private;
5896 	struct bitmap *bitmap;
5897 
5898 	if (v == (void*)1) {
5899 		struct mdk_personality *pers;
5900 		seq_printf(seq, "Personalities : ");
5901 		spin_lock(&pers_lock);
5902 		list_for_each_entry(pers, &pers_list, list)
5903 			seq_printf(seq, "[%s] ", pers->name);
5904 
5905 		spin_unlock(&pers_lock);
5906 		seq_printf(seq, "\n");
5907 		mi->event = atomic_read(&md_event_count);
5908 		return 0;
5909 	}
5910 	if (v == (void*)2) {
5911 		status_unused(seq);
5912 		return 0;
5913 	}
5914 
5915 	if (mddev_lock(mddev) < 0)
5916 		return -EINTR;
5917 
5918 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
5919 		seq_printf(seq, "%s : %sactive", mdname(mddev),
5920 						mddev->pers ? "" : "in");
5921 		if (mddev->pers) {
5922 			if (mddev->ro==1)
5923 				seq_printf(seq, " (read-only)");
5924 			if (mddev->ro==2)
5925 				seq_printf(seq, " (auto-read-only)");
5926 			seq_printf(seq, " %s", mddev->pers->name);
5927 		}
5928 
5929 		sectors = 0;
5930 		list_for_each_entry(rdev, &mddev->disks, same_set) {
5931 			char b[BDEVNAME_SIZE];
5932 			seq_printf(seq, " %s[%d]",
5933 				bdevname(rdev->bdev,b), rdev->desc_nr);
5934 			if (test_bit(WriteMostly, &rdev->flags))
5935 				seq_printf(seq, "(W)");
5936 			if (test_bit(Faulty, &rdev->flags)) {
5937 				seq_printf(seq, "(F)");
5938 				continue;
5939 			} else if (rdev->raid_disk < 0)
5940 				seq_printf(seq, "(S)"); /* spare */
5941 			sectors += rdev->sectors;
5942 		}
5943 
5944 		if (!list_empty(&mddev->disks)) {
5945 			if (mddev->pers)
5946 				seq_printf(seq, "\n      %llu blocks",
5947 					   (unsigned long long)
5948 					   mddev->array_sectors / 2);
5949 			else
5950 				seq_printf(seq, "\n      %llu blocks",
5951 					   (unsigned long long)sectors / 2);
5952 		}
5953 		if (mddev->persistent) {
5954 			if (mddev->major_version != 0 ||
5955 			    mddev->minor_version != 90) {
5956 				seq_printf(seq," super %d.%d",
5957 					   mddev->major_version,
5958 					   mddev->minor_version);
5959 			}
5960 		} else if (mddev->external)
5961 			seq_printf(seq, " super external:%s",
5962 				   mddev->metadata_type);
5963 		else
5964 			seq_printf(seq, " super non-persistent");
5965 
5966 		if (mddev->pers) {
5967 			mddev->pers->status(seq, mddev);
5968 	 		seq_printf(seq, "\n      ");
5969 			if (mddev->pers->sync_request) {
5970 				if (mddev->curr_resync > 2) {
5971 					status_resync(seq, mddev);
5972 					seq_printf(seq, "\n      ");
5973 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
5974 					seq_printf(seq, "\tresync=DELAYED\n      ");
5975 				else if (mddev->recovery_cp < MaxSector)
5976 					seq_printf(seq, "\tresync=PENDING\n      ");
5977 			}
5978 		} else
5979 			seq_printf(seq, "\n       ");
5980 
5981 		if ((bitmap = mddev->bitmap)) {
5982 			unsigned long chunk_kb;
5983 			unsigned long flags;
5984 			spin_lock_irqsave(&bitmap->lock, flags);
5985 			chunk_kb = bitmap->chunksize >> 10;
5986 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
5987 				"%lu%s chunk",
5988 				bitmap->pages - bitmap->missing_pages,
5989 				bitmap->pages,
5990 				(bitmap->pages - bitmap->missing_pages)
5991 					<< (PAGE_SHIFT - 10),
5992 				chunk_kb ? chunk_kb : bitmap->chunksize,
5993 				chunk_kb ? "KB" : "B");
5994 			if (bitmap->file) {
5995 				seq_printf(seq, ", file: ");
5996 				seq_path(seq, &bitmap->file->f_path, " \t\n");
5997 			}
5998 
5999 			seq_printf(seq, "\n");
6000 			spin_unlock_irqrestore(&bitmap->lock, flags);
6001 		}
6002 
6003 		seq_printf(seq, "\n");
6004 	}
6005 	mddev_unlock(mddev);
6006 
6007 	return 0;
6008 }
6009 
6010 static const struct seq_operations md_seq_ops = {
6011 	.start  = md_seq_start,
6012 	.next   = md_seq_next,
6013 	.stop   = md_seq_stop,
6014 	.show   = md_seq_show,
6015 };
6016 
6017 static int md_seq_open(struct inode *inode, struct file *file)
6018 {
6019 	int error;
6020 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
6021 	if (mi == NULL)
6022 		return -ENOMEM;
6023 
6024 	error = seq_open(file, &md_seq_ops);
6025 	if (error)
6026 		kfree(mi);
6027 	else {
6028 		struct seq_file *p = file->private_data;
6029 		p->private = mi;
6030 		mi->event = atomic_read(&md_event_count);
6031 	}
6032 	return error;
6033 }
6034 
6035 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6036 {
6037 	struct seq_file *m = filp->private_data;
6038 	struct mdstat_info *mi = m->private;
6039 	int mask;
6040 
6041 	poll_wait(filp, &md_event_waiters, wait);
6042 
6043 	/* always allow read */
6044 	mask = POLLIN | POLLRDNORM;
6045 
6046 	if (mi->event != atomic_read(&md_event_count))
6047 		mask |= POLLERR | POLLPRI;
6048 	return mask;
6049 }
6050 
6051 static const struct file_operations md_seq_fops = {
6052 	.owner		= THIS_MODULE,
6053 	.open           = md_seq_open,
6054 	.read           = seq_read,
6055 	.llseek         = seq_lseek,
6056 	.release	= seq_release_private,
6057 	.poll		= mdstat_poll,
6058 };
6059 
6060 int register_md_personality(struct mdk_personality *p)
6061 {
6062 	spin_lock(&pers_lock);
6063 	list_add_tail(&p->list, &pers_list);
6064 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6065 	spin_unlock(&pers_lock);
6066 	return 0;
6067 }
6068 
6069 int unregister_md_personality(struct mdk_personality *p)
6070 {
6071 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6072 	spin_lock(&pers_lock);
6073 	list_del_init(&p->list);
6074 	spin_unlock(&pers_lock);
6075 	return 0;
6076 }
6077 
6078 static int is_mddev_idle(mddev_t *mddev, int init)
6079 {
6080 	mdk_rdev_t * rdev;
6081 	int idle;
6082 	int curr_events;
6083 
6084 	idle = 1;
6085 	rcu_read_lock();
6086 	rdev_for_each_rcu(rdev, mddev) {
6087 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6088 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6089 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6090 			      atomic_read(&disk->sync_io);
6091 		/* sync IO will cause sync_io to increase before the disk_stats
6092 		 * as sync_io is counted when a request starts, and
6093 		 * disk_stats is counted when it completes.
6094 		 * So resync activity will cause curr_events to be smaller than
6095 		 * when there was no such activity.
6096 		 * non-sync IO will cause disk_stat to increase without
6097 		 * increasing sync_io so curr_events will (eventually)
6098 		 * be larger than it was before.  Once it becomes
6099 		 * substantially larger, the test below will cause
6100 		 * the array to appear non-idle, and resync will slow
6101 		 * down.
6102 		 * If there is a lot of outstanding resync activity when
6103 		 * we set last_event to curr_events, then all that activity
6104 		 * completing might cause the array to appear non-idle
6105 		 * and resync will be slowed down even though there might
6106 		 * not have been non-resync activity.  This will only
6107 		 * happen once though.  'last_events' will soon reflect
6108 		 * the state where there is little or no outstanding
6109 		 * resync requests, and further resync activity will
6110 		 * always make curr_events less than last_events.
6111 		 *
6112 		 */
6113 		if (init || curr_events - rdev->last_events > 64) {
6114 			rdev->last_events = curr_events;
6115 			idle = 0;
6116 		}
6117 	}
6118 	rcu_read_unlock();
6119 	return idle;
6120 }
6121 
6122 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6123 {
6124 	/* another "blocks" (512byte) blocks have been synced */
6125 	atomic_sub(blocks, &mddev->recovery_active);
6126 	wake_up(&mddev->recovery_wait);
6127 	if (!ok) {
6128 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6129 		md_wakeup_thread(mddev->thread);
6130 		// stop recovery, signal do_sync ....
6131 	}
6132 }
6133 
6134 
6135 /* md_write_start(mddev, bi)
6136  * If we need to update some array metadata (e.g. 'active' flag
6137  * in superblock) before writing, schedule a superblock update
6138  * and wait for it to complete.
6139  */
6140 void md_write_start(mddev_t *mddev, struct bio *bi)
6141 {
6142 	int did_change = 0;
6143 	if (bio_data_dir(bi) != WRITE)
6144 		return;
6145 
6146 	BUG_ON(mddev->ro == 1);
6147 	if (mddev->ro == 2) {
6148 		/* need to switch to read/write */
6149 		mddev->ro = 0;
6150 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6151 		md_wakeup_thread(mddev->thread);
6152 		md_wakeup_thread(mddev->sync_thread);
6153 		did_change = 1;
6154 	}
6155 	atomic_inc(&mddev->writes_pending);
6156 	if (mddev->safemode == 1)
6157 		mddev->safemode = 0;
6158 	if (mddev->in_sync) {
6159 		spin_lock_irq(&mddev->write_lock);
6160 		if (mddev->in_sync) {
6161 			mddev->in_sync = 0;
6162 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6163 			md_wakeup_thread(mddev->thread);
6164 			did_change = 1;
6165 		}
6166 		spin_unlock_irq(&mddev->write_lock);
6167 	}
6168 	if (did_change)
6169 		sysfs_notify_dirent(mddev->sysfs_state);
6170 	wait_event(mddev->sb_wait,
6171 		   !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
6172 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6173 }
6174 
6175 void md_write_end(mddev_t *mddev)
6176 {
6177 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6178 		if (mddev->safemode == 2)
6179 			md_wakeup_thread(mddev->thread);
6180 		else if (mddev->safemode_delay)
6181 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6182 	}
6183 }
6184 
6185 /* md_allow_write(mddev)
6186  * Calling this ensures that the array is marked 'active' so that writes
6187  * may proceed without blocking.  It is important to call this before
6188  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6189  * Must be called with mddev_lock held.
6190  *
6191  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6192  * is dropped, so return -EAGAIN after notifying userspace.
6193  */
6194 int md_allow_write(mddev_t *mddev)
6195 {
6196 	if (!mddev->pers)
6197 		return 0;
6198 	if (mddev->ro)
6199 		return 0;
6200 	if (!mddev->pers->sync_request)
6201 		return 0;
6202 
6203 	spin_lock_irq(&mddev->write_lock);
6204 	if (mddev->in_sync) {
6205 		mddev->in_sync = 0;
6206 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6207 		if (mddev->safemode_delay &&
6208 		    mddev->safemode == 0)
6209 			mddev->safemode = 1;
6210 		spin_unlock_irq(&mddev->write_lock);
6211 		md_update_sb(mddev, 0);
6212 		sysfs_notify_dirent(mddev->sysfs_state);
6213 	} else
6214 		spin_unlock_irq(&mddev->write_lock);
6215 
6216 	if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
6217 		return -EAGAIN;
6218 	else
6219 		return 0;
6220 }
6221 EXPORT_SYMBOL_GPL(md_allow_write);
6222 
6223 #define SYNC_MARKS	10
6224 #define	SYNC_MARK_STEP	(3*HZ)
6225 void md_do_sync(mddev_t *mddev)
6226 {
6227 	mddev_t *mddev2;
6228 	unsigned int currspeed = 0,
6229 		 window;
6230 	sector_t max_sectors,j, io_sectors;
6231 	unsigned long mark[SYNC_MARKS];
6232 	sector_t mark_cnt[SYNC_MARKS];
6233 	int last_mark,m;
6234 	struct list_head *tmp;
6235 	sector_t last_check;
6236 	int skipped = 0;
6237 	mdk_rdev_t *rdev;
6238 	char *desc;
6239 
6240 	/* just incase thread restarts... */
6241 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6242 		return;
6243 	if (mddev->ro) /* never try to sync a read-only array */
6244 		return;
6245 
6246 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6247 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6248 			desc = "data-check";
6249 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6250 			desc = "requested-resync";
6251 		else
6252 			desc = "resync";
6253 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6254 		desc = "reshape";
6255 	else
6256 		desc = "recovery";
6257 
6258 	/* we overload curr_resync somewhat here.
6259 	 * 0 == not engaged in resync at all
6260 	 * 2 == checking that there is no conflict with another sync
6261 	 * 1 == like 2, but have yielded to allow conflicting resync to
6262 	 *		commense
6263 	 * other == active in resync - this many blocks
6264 	 *
6265 	 * Before starting a resync we must have set curr_resync to
6266 	 * 2, and then checked that every "conflicting" array has curr_resync
6267 	 * less than ours.  When we find one that is the same or higher
6268 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6269 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6270 	 * This will mean we have to start checking from the beginning again.
6271 	 *
6272 	 */
6273 
6274 	do {
6275 		mddev->curr_resync = 2;
6276 
6277 	try_again:
6278 		if (kthread_should_stop()) {
6279 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6280 			goto skip;
6281 		}
6282 		for_each_mddev(mddev2, tmp) {
6283 			if (mddev2 == mddev)
6284 				continue;
6285 			if (!mddev->parallel_resync
6286 			&&  mddev2->curr_resync
6287 			&&  match_mddev_units(mddev, mddev2)) {
6288 				DEFINE_WAIT(wq);
6289 				if (mddev < mddev2 && mddev->curr_resync == 2) {
6290 					/* arbitrarily yield */
6291 					mddev->curr_resync = 1;
6292 					wake_up(&resync_wait);
6293 				}
6294 				if (mddev > mddev2 && mddev->curr_resync == 1)
6295 					/* no need to wait here, we can wait the next
6296 					 * time 'round when curr_resync == 2
6297 					 */
6298 					continue;
6299 				/* We need to wait 'interruptible' so as not to
6300 				 * contribute to the load average, and not to
6301 				 * be caught by 'softlockup'
6302 				 */
6303 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
6304 				if (!kthread_should_stop() &&
6305 				    mddev2->curr_resync >= mddev->curr_resync) {
6306 					printk(KERN_INFO "md: delaying %s of %s"
6307 					       " until %s has finished (they"
6308 					       " share one or more physical units)\n",
6309 					       desc, mdname(mddev), mdname(mddev2));
6310 					mddev_put(mddev2);
6311 					if (signal_pending(current))
6312 						flush_signals(current);
6313 					schedule();
6314 					finish_wait(&resync_wait, &wq);
6315 					goto try_again;
6316 				}
6317 				finish_wait(&resync_wait, &wq);
6318 			}
6319 		}
6320 	} while (mddev->curr_resync < 2);
6321 
6322 	j = 0;
6323 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6324 		/* resync follows the size requested by the personality,
6325 		 * which defaults to physical size, but can be virtual size
6326 		 */
6327 		max_sectors = mddev->resync_max_sectors;
6328 		mddev->resync_mismatches = 0;
6329 		/* we don't use the checkpoint if there's a bitmap */
6330 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6331 			j = mddev->resync_min;
6332 		else if (!mddev->bitmap)
6333 			j = mddev->recovery_cp;
6334 
6335 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6336 		max_sectors = mddev->dev_sectors;
6337 	else {
6338 		/* recovery follows the physical size of devices */
6339 		max_sectors = mddev->dev_sectors;
6340 		j = MaxSector;
6341 		list_for_each_entry(rdev, &mddev->disks, same_set)
6342 			if (rdev->raid_disk >= 0 &&
6343 			    !test_bit(Faulty, &rdev->flags) &&
6344 			    !test_bit(In_sync, &rdev->flags) &&
6345 			    rdev->recovery_offset < j)
6346 				j = rdev->recovery_offset;
6347 	}
6348 
6349 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
6350 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
6351 		" %d KB/sec/disk.\n", speed_min(mddev));
6352 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6353 	       "(but not more than %d KB/sec) for %s.\n",
6354 	       speed_max(mddev), desc);
6355 
6356 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
6357 
6358 	io_sectors = 0;
6359 	for (m = 0; m < SYNC_MARKS; m++) {
6360 		mark[m] = jiffies;
6361 		mark_cnt[m] = io_sectors;
6362 	}
6363 	last_mark = 0;
6364 	mddev->resync_mark = mark[last_mark];
6365 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6366 
6367 	/*
6368 	 * Tune reconstruction:
6369 	 */
6370 	window = 32*(PAGE_SIZE/512);
6371 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6372 		window/2,(unsigned long long) max_sectors/2);
6373 
6374 	atomic_set(&mddev->recovery_active, 0);
6375 	last_check = 0;
6376 
6377 	if (j>2) {
6378 		printk(KERN_INFO
6379 		       "md: resuming %s of %s from checkpoint.\n",
6380 		       desc, mdname(mddev));
6381 		mddev->curr_resync = j;
6382 	}
6383 
6384 	while (j < max_sectors) {
6385 		sector_t sectors;
6386 
6387 		skipped = 0;
6388 
6389 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6390 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
6391 		      (mddev->curr_resync - mddev->curr_resync_completed)
6392 		      > (max_sectors >> 4)) ||
6393 		     (j - mddev->curr_resync_completed)*2
6394 		     >= mddev->resync_max - mddev->curr_resync_completed
6395 			    )) {
6396 			/* time to update curr_resync_completed */
6397 			blk_unplug(mddev->queue);
6398 			wait_event(mddev->recovery_wait,
6399 				   atomic_read(&mddev->recovery_active) == 0);
6400 			mddev->curr_resync_completed =
6401 				mddev->curr_resync;
6402 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6403 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6404 		}
6405 
6406 		while (j >= mddev->resync_max && !kthread_should_stop()) {
6407 			/* As this condition is controlled by user-space,
6408 			 * we can block indefinitely, so use '_interruptible'
6409 			 * to avoid triggering warnings.
6410 			 */
6411 			flush_signals(current); /* just in case */
6412 			wait_event_interruptible(mddev->recovery_wait,
6413 						 mddev->resync_max > j
6414 						 || kthread_should_stop());
6415 		}
6416 
6417 		if (kthread_should_stop())
6418 			goto interrupted;
6419 
6420 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6421 						  currspeed < speed_min(mddev));
6422 		if (sectors == 0) {
6423 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6424 			goto out;
6425 		}
6426 
6427 		if (!skipped) { /* actual IO requested */
6428 			io_sectors += sectors;
6429 			atomic_add(sectors, &mddev->recovery_active);
6430 		}
6431 
6432 		j += sectors;
6433 		if (j>1) mddev->curr_resync = j;
6434 		mddev->curr_mark_cnt = io_sectors;
6435 		if (last_check == 0)
6436 			/* this is the earliers that rebuilt will be
6437 			 * visible in /proc/mdstat
6438 			 */
6439 			md_new_event(mddev);
6440 
6441 		if (last_check + window > io_sectors || j == max_sectors)
6442 			continue;
6443 
6444 		last_check = io_sectors;
6445 
6446 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6447 			break;
6448 
6449 	repeat:
6450 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6451 			/* step marks */
6452 			int next = (last_mark+1) % SYNC_MARKS;
6453 
6454 			mddev->resync_mark = mark[next];
6455 			mddev->resync_mark_cnt = mark_cnt[next];
6456 			mark[next] = jiffies;
6457 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6458 			last_mark = next;
6459 		}
6460 
6461 
6462 		if (kthread_should_stop())
6463 			goto interrupted;
6464 
6465 
6466 		/*
6467 		 * this loop exits only if either when we are slower than
6468 		 * the 'hard' speed limit, or the system was IO-idle for
6469 		 * a jiffy.
6470 		 * the system might be non-idle CPU-wise, but we only care
6471 		 * about not overloading the IO subsystem. (things like an
6472 		 * e2fsck being done on the RAID array should execute fast)
6473 		 */
6474 		blk_unplug(mddev->queue);
6475 		cond_resched();
6476 
6477 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6478 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6479 
6480 		if (currspeed > speed_min(mddev)) {
6481 			if ((currspeed > speed_max(mddev)) ||
6482 					!is_mddev_idle(mddev, 0)) {
6483 				msleep(500);
6484 				goto repeat;
6485 			}
6486 		}
6487 	}
6488 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6489 	/*
6490 	 * this also signals 'finished resyncing' to md_stop
6491 	 */
6492  out:
6493 	blk_unplug(mddev->queue);
6494 
6495 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6496 
6497 	/* tell personality that we are finished */
6498 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6499 
6500 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6501 	    mddev->curr_resync > 2) {
6502 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6503 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6504 				if (mddev->curr_resync >= mddev->recovery_cp) {
6505 					printk(KERN_INFO
6506 					       "md: checkpointing %s of %s.\n",
6507 					       desc, mdname(mddev));
6508 					mddev->recovery_cp = mddev->curr_resync;
6509 				}
6510 			} else
6511 				mddev->recovery_cp = MaxSector;
6512 		} else {
6513 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6514 				mddev->curr_resync = MaxSector;
6515 			list_for_each_entry(rdev, &mddev->disks, same_set)
6516 				if (rdev->raid_disk >= 0 &&
6517 				    !test_bit(Faulty, &rdev->flags) &&
6518 				    !test_bit(In_sync, &rdev->flags) &&
6519 				    rdev->recovery_offset < mddev->curr_resync)
6520 					rdev->recovery_offset = mddev->curr_resync;
6521 		}
6522 	}
6523 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6524 
6525  skip:
6526 	mddev->curr_resync = 0;
6527 	mddev->curr_resync_completed = 0;
6528 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6529 		/* We completed so max setting can be forgotten. */
6530 		mddev->resync_max = MaxSector;
6531 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6532 	wake_up(&resync_wait);
6533 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6534 	md_wakeup_thread(mddev->thread);
6535 	return;
6536 
6537  interrupted:
6538 	/*
6539 	 * got a signal, exit.
6540 	 */
6541 	printk(KERN_INFO
6542 	       "md: md_do_sync() got signal ... exiting\n");
6543 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6544 	goto out;
6545 
6546 }
6547 EXPORT_SYMBOL_GPL(md_do_sync);
6548 
6549 
6550 static int remove_and_add_spares(mddev_t *mddev)
6551 {
6552 	mdk_rdev_t *rdev;
6553 	int spares = 0;
6554 
6555 	mddev->curr_resync_completed = 0;
6556 
6557 	list_for_each_entry(rdev, &mddev->disks, same_set)
6558 		if (rdev->raid_disk >= 0 &&
6559 		    !test_bit(Blocked, &rdev->flags) &&
6560 		    (test_bit(Faulty, &rdev->flags) ||
6561 		     ! test_bit(In_sync, &rdev->flags)) &&
6562 		    atomic_read(&rdev->nr_pending)==0) {
6563 			if (mddev->pers->hot_remove_disk(
6564 				    mddev, rdev->raid_disk)==0) {
6565 				char nm[20];
6566 				sprintf(nm,"rd%d", rdev->raid_disk);
6567 				sysfs_remove_link(&mddev->kobj, nm);
6568 				rdev->raid_disk = -1;
6569 			}
6570 		}
6571 
6572 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
6573 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6574 			if (rdev->raid_disk >= 0 &&
6575 			    !test_bit(In_sync, &rdev->flags) &&
6576 			    !test_bit(Blocked, &rdev->flags))
6577 				spares++;
6578 			if (rdev->raid_disk < 0
6579 			    && !test_bit(Faulty, &rdev->flags)) {
6580 				rdev->recovery_offset = 0;
6581 				if (mddev->pers->
6582 				    hot_add_disk(mddev, rdev) == 0) {
6583 					char nm[20];
6584 					sprintf(nm, "rd%d", rdev->raid_disk);
6585 					if (sysfs_create_link(&mddev->kobj,
6586 							      &rdev->kobj, nm))
6587 						printk(KERN_WARNING
6588 						       "md: cannot register "
6589 						       "%s for %s\n",
6590 						       nm, mdname(mddev));
6591 					spares++;
6592 					md_new_event(mddev);
6593 				} else
6594 					break;
6595 			}
6596 		}
6597 	}
6598 	return spares;
6599 }
6600 /*
6601  * This routine is regularly called by all per-raid-array threads to
6602  * deal with generic issues like resync and super-block update.
6603  * Raid personalities that don't have a thread (linear/raid0) do not
6604  * need this as they never do any recovery or update the superblock.
6605  *
6606  * It does not do any resync itself, but rather "forks" off other threads
6607  * to do that as needed.
6608  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
6609  * "->recovery" and create a thread at ->sync_thread.
6610  * When the thread finishes it sets MD_RECOVERY_DONE
6611  * and wakeups up this thread which will reap the thread and finish up.
6612  * This thread also removes any faulty devices (with nr_pending == 0).
6613  *
6614  * The overall approach is:
6615  *  1/ if the superblock needs updating, update it.
6616  *  2/ If a recovery thread is running, don't do anything else.
6617  *  3/ If recovery has finished, clean up, possibly marking spares active.
6618  *  4/ If there are any faulty devices, remove them.
6619  *  5/ If array is degraded, try to add spares devices
6620  *  6/ If array has spares or is not in-sync, start a resync thread.
6621  */
6622 void md_check_recovery(mddev_t *mddev)
6623 {
6624 	mdk_rdev_t *rdev;
6625 
6626 
6627 	if (mddev->bitmap)
6628 		bitmap_daemon_work(mddev->bitmap);
6629 
6630 	if (mddev->ro)
6631 		return;
6632 
6633 	if (signal_pending(current)) {
6634 		if (mddev->pers->sync_request && !mddev->external) {
6635 			printk(KERN_INFO "md: %s in immediate safe mode\n",
6636 			       mdname(mddev));
6637 			mddev->safemode = 2;
6638 		}
6639 		flush_signals(current);
6640 	}
6641 
6642 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
6643 		return;
6644 	if ( ! (
6645 		(mddev->flags && !mddev->external) ||
6646 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
6647 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
6648 		(mddev->external == 0 && mddev->safemode == 1) ||
6649 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
6650 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
6651 		))
6652 		return;
6653 
6654 	if (mddev_trylock(mddev)) {
6655 		int spares = 0;
6656 
6657 		if (mddev->ro) {
6658 			/* Only thing we do on a ro array is remove
6659 			 * failed devices.
6660 			 */
6661 			remove_and_add_spares(mddev);
6662 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6663 			goto unlock;
6664 		}
6665 
6666 		if (!mddev->external) {
6667 			int did_change = 0;
6668 			spin_lock_irq(&mddev->write_lock);
6669 			if (mddev->safemode &&
6670 			    !atomic_read(&mddev->writes_pending) &&
6671 			    !mddev->in_sync &&
6672 			    mddev->recovery_cp == MaxSector) {
6673 				mddev->in_sync = 1;
6674 				did_change = 1;
6675 				if (mddev->persistent)
6676 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6677 			}
6678 			if (mddev->safemode == 1)
6679 				mddev->safemode = 0;
6680 			spin_unlock_irq(&mddev->write_lock);
6681 			if (did_change)
6682 				sysfs_notify_dirent(mddev->sysfs_state);
6683 		}
6684 
6685 		if (mddev->flags)
6686 			md_update_sb(mddev, 0);
6687 
6688 		list_for_each_entry(rdev, &mddev->disks, same_set)
6689 			if (test_and_clear_bit(StateChanged, &rdev->flags))
6690 				sysfs_notify_dirent(rdev->sysfs_state);
6691 
6692 
6693 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
6694 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
6695 			/* resync/recovery still happening */
6696 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6697 			goto unlock;
6698 		}
6699 		if (mddev->sync_thread) {
6700 			/* resync has finished, collect result */
6701 			md_unregister_thread(mddev->sync_thread);
6702 			mddev->sync_thread = NULL;
6703 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
6704 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
6705 				/* success...*/
6706 				/* activate any spares */
6707 				if (mddev->pers->spare_active(mddev))
6708 					sysfs_notify(&mddev->kobj, NULL,
6709 						     "degraded");
6710 			}
6711 			if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6712 			    mddev->pers->finish_reshape)
6713 				mddev->pers->finish_reshape(mddev);
6714 			md_update_sb(mddev, 1);
6715 
6716 			/* if array is no-longer degraded, then any saved_raid_disk
6717 			 * information must be scrapped
6718 			 */
6719 			if (!mddev->degraded)
6720 				list_for_each_entry(rdev, &mddev->disks, same_set)
6721 					rdev->saved_raid_disk = -1;
6722 
6723 			mddev->recovery = 0;
6724 			/* flag recovery needed just to double check */
6725 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6726 			sysfs_notify_dirent(mddev->sysfs_action);
6727 			md_new_event(mddev);
6728 			goto unlock;
6729 		}
6730 		/* Set RUNNING before clearing NEEDED to avoid
6731 		 * any transients in the value of "sync_action".
6732 		 */
6733 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6734 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6735 		/* Clear some bits that don't mean anything, but
6736 		 * might be left set
6737 		 */
6738 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
6739 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
6740 
6741 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
6742 			goto unlock;
6743 		/* no recovery is running.
6744 		 * remove any failed drives, then
6745 		 * add spares if possible.
6746 		 * Spare are also removed and re-added, to allow
6747 		 * the personality to fail the re-add.
6748 		 */
6749 
6750 		if (mddev->reshape_position != MaxSector) {
6751 			if (mddev->pers->check_reshape == NULL ||
6752 			    mddev->pers->check_reshape(mddev) != 0)
6753 				/* Cannot proceed */
6754 				goto unlock;
6755 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6756 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6757 		} else if ((spares = remove_and_add_spares(mddev))) {
6758 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6759 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6760 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
6761 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6762 		} else if (mddev->recovery_cp < MaxSector) {
6763 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6764 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6765 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6766 			/* nothing to be done ... */
6767 			goto unlock;
6768 
6769 		if (mddev->pers->sync_request) {
6770 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
6771 				/* We are adding a device or devices to an array
6772 				 * which has the bitmap stored on all devices.
6773 				 * So make sure all bitmap pages get written
6774 				 */
6775 				bitmap_write_all(mddev->bitmap);
6776 			}
6777 			mddev->sync_thread = md_register_thread(md_do_sync,
6778 								mddev,
6779 								"resync");
6780 			if (!mddev->sync_thread) {
6781 				printk(KERN_ERR "%s: could not start resync"
6782 					" thread...\n",
6783 					mdname(mddev));
6784 				/* leave the spares where they are, it shouldn't hurt */
6785 				mddev->recovery = 0;
6786 			} else
6787 				md_wakeup_thread(mddev->sync_thread);
6788 			sysfs_notify_dirent(mddev->sysfs_action);
6789 			md_new_event(mddev);
6790 		}
6791 	unlock:
6792 		if (!mddev->sync_thread) {
6793 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6794 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
6795 					       &mddev->recovery))
6796 				if (mddev->sysfs_action)
6797 					sysfs_notify_dirent(mddev->sysfs_action);
6798 		}
6799 		mddev_unlock(mddev);
6800 	}
6801 }
6802 
6803 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
6804 {
6805 	sysfs_notify_dirent(rdev->sysfs_state);
6806 	wait_event_timeout(rdev->blocked_wait,
6807 			   !test_bit(Blocked, &rdev->flags),
6808 			   msecs_to_jiffies(5000));
6809 	rdev_dec_pending(rdev, mddev);
6810 }
6811 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
6812 
6813 static int md_notify_reboot(struct notifier_block *this,
6814 			    unsigned long code, void *x)
6815 {
6816 	struct list_head *tmp;
6817 	mddev_t *mddev;
6818 
6819 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
6820 
6821 		printk(KERN_INFO "md: stopping all md devices.\n");
6822 
6823 		for_each_mddev(mddev, tmp)
6824 			if (mddev_trylock(mddev)) {
6825 				/* Force a switch to readonly even array
6826 				 * appears to still be in use.  Hence
6827 				 * the '100'.
6828 				 */
6829 				do_md_stop(mddev, 1, 100);
6830 				mddev_unlock(mddev);
6831 			}
6832 		/*
6833 		 * certain more exotic SCSI devices are known to be
6834 		 * volatile wrt too early system reboots. While the
6835 		 * right place to handle this issue is the given
6836 		 * driver, we do want to have a safe RAID driver ...
6837 		 */
6838 		mdelay(1000*1);
6839 	}
6840 	return NOTIFY_DONE;
6841 }
6842 
6843 static struct notifier_block md_notifier = {
6844 	.notifier_call	= md_notify_reboot,
6845 	.next		= NULL,
6846 	.priority	= INT_MAX, /* before any real devices */
6847 };
6848 
6849 static void md_geninit(void)
6850 {
6851 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
6852 
6853 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
6854 }
6855 
6856 static int __init md_init(void)
6857 {
6858 	if (register_blkdev(MD_MAJOR, "md"))
6859 		return -1;
6860 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
6861 		unregister_blkdev(MD_MAJOR, "md");
6862 		return -1;
6863 	}
6864 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
6865 			    md_probe, NULL, NULL);
6866 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
6867 			    md_probe, NULL, NULL);
6868 
6869 	register_reboot_notifier(&md_notifier);
6870 	raid_table_header = register_sysctl_table(raid_root_table);
6871 
6872 	md_geninit();
6873 	return 0;
6874 }
6875 
6876 
6877 #ifndef MODULE
6878 
6879 /*
6880  * Searches all registered partitions for autorun RAID arrays
6881  * at boot time.
6882  */
6883 
6884 static LIST_HEAD(all_detected_devices);
6885 struct detected_devices_node {
6886 	struct list_head list;
6887 	dev_t dev;
6888 };
6889 
6890 void md_autodetect_dev(dev_t dev)
6891 {
6892 	struct detected_devices_node *node_detected_dev;
6893 
6894 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
6895 	if (node_detected_dev) {
6896 		node_detected_dev->dev = dev;
6897 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
6898 	} else {
6899 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
6900 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
6901 	}
6902 }
6903 
6904 
6905 static void autostart_arrays(int part)
6906 {
6907 	mdk_rdev_t *rdev;
6908 	struct detected_devices_node *node_detected_dev;
6909 	dev_t dev;
6910 	int i_scanned, i_passed;
6911 
6912 	i_scanned = 0;
6913 	i_passed = 0;
6914 
6915 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
6916 
6917 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
6918 		i_scanned++;
6919 		node_detected_dev = list_entry(all_detected_devices.next,
6920 					struct detected_devices_node, list);
6921 		list_del(&node_detected_dev->list);
6922 		dev = node_detected_dev->dev;
6923 		kfree(node_detected_dev);
6924 		rdev = md_import_device(dev,0, 90);
6925 		if (IS_ERR(rdev))
6926 			continue;
6927 
6928 		if (test_bit(Faulty, &rdev->flags)) {
6929 			MD_BUG();
6930 			continue;
6931 		}
6932 		set_bit(AutoDetected, &rdev->flags);
6933 		list_add(&rdev->same_set, &pending_raid_disks);
6934 		i_passed++;
6935 	}
6936 
6937 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
6938 						i_scanned, i_passed);
6939 
6940 	autorun_devices(part);
6941 }
6942 
6943 #endif /* !MODULE */
6944 
6945 static __exit void md_exit(void)
6946 {
6947 	mddev_t *mddev;
6948 	struct list_head *tmp;
6949 
6950 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
6951 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
6952 
6953 	unregister_blkdev(MD_MAJOR,"md");
6954 	unregister_blkdev(mdp_major, "mdp");
6955 	unregister_reboot_notifier(&md_notifier);
6956 	unregister_sysctl_table(raid_table_header);
6957 	remove_proc_entry("mdstat", NULL);
6958 	for_each_mddev(mddev, tmp) {
6959 		export_array(mddev);
6960 		mddev->hold_active = 0;
6961 	}
6962 }
6963 
6964 subsys_initcall(md_init);
6965 module_exit(md_exit)
6966 
6967 static int get_ro(char *buffer, struct kernel_param *kp)
6968 {
6969 	return sprintf(buffer, "%d", start_readonly);
6970 }
6971 static int set_ro(const char *val, struct kernel_param *kp)
6972 {
6973 	char *e;
6974 	int num = simple_strtoul(val, &e, 10);
6975 	if (*val && (*e == '\0' || *e == '\n')) {
6976 		start_readonly = num;
6977 		return 0;
6978 	}
6979 	return -EINVAL;
6980 }
6981 
6982 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
6983 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
6984 
6985 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
6986 
6987 EXPORT_SYMBOL(register_md_personality);
6988 EXPORT_SYMBOL(unregister_md_personality);
6989 EXPORT_SYMBOL(md_error);
6990 EXPORT_SYMBOL(md_done_sync);
6991 EXPORT_SYMBOL(md_write_start);
6992 EXPORT_SYMBOL(md_write_end);
6993 EXPORT_SYMBOL(md_register_thread);
6994 EXPORT_SYMBOL(md_unregister_thread);
6995 EXPORT_SYMBOL(md_wakeup_thread);
6996 EXPORT_SYMBOL(md_check_recovery);
6997 MODULE_LICENSE("GPL");
6998 MODULE_ALIAS("md");
6999 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
7000