xref: /linux/drivers/md/md.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/blkdev.h>
37 #include <linux/sysctl.h>
38 #include <linux/seq_file.h>
39 #include <linux/buffer_head.h> /* for invalidate_bdev */
40 #include <linux/poll.h>
41 #include <linux/ctype.h>
42 #include <linux/hdreg.h>
43 #include <linux/proc_fs.h>
44 #include <linux/random.h>
45 #include <linux/reboot.h>
46 #include <linux/file.h>
47 #include <linux/delay.h>
48 #include <linux/raid/md_p.h>
49 #include <linux/raid/md_u.h>
50 #include "md.h"
51 #include "bitmap.h"
52 
53 #define DEBUG 0
54 #define dprintk(x...) ((void)(DEBUG && printk(x)))
55 
56 
57 #ifndef MODULE
58 static void autostart_arrays(int part);
59 #endif
60 
61 static LIST_HEAD(pers_list);
62 static DEFINE_SPINLOCK(pers_lock);
63 
64 static void md_print_devices(void);
65 
66 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
67 
68 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
69 
70 /*
71  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
72  * is 1000 KB/sec, so the extra system load does not show up that much.
73  * Increase it if you want to have more _guaranteed_ speed. Note that
74  * the RAID driver will use the maximum available bandwidth if the IO
75  * subsystem is idle. There is also an 'absolute maximum' reconstruction
76  * speed limit - in case reconstruction slows down your system despite
77  * idle IO detection.
78  *
79  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
80  * or /sys/block/mdX/md/sync_speed_{min,max}
81  */
82 
83 static int sysctl_speed_limit_min = 1000;
84 static int sysctl_speed_limit_max = 200000;
85 static inline int speed_min(mddev_t *mddev)
86 {
87 	return mddev->sync_speed_min ?
88 		mddev->sync_speed_min : sysctl_speed_limit_min;
89 }
90 
91 static inline int speed_max(mddev_t *mddev)
92 {
93 	return mddev->sync_speed_max ?
94 		mddev->sync_speed_max : sysctl_speed_limit_max;
95 }
96 
97 static struct ctl_table_header *raid_table_header;
98 
99 static ctl_table raid_table[] = {
100 	{
101 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MIN,
102 		.procname	= "speed_limit_min",
103 		.data		= &sysctl_speed_limit_min,
104 		.maxlen		= sizeof(int),
105 		.mode		= S_IRUGO|S_IWUSR,
106 		.proc_handler	= &proc_dointvec,
107 	},
108 	{
109 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MAX,
110 		.procname	= "speed_limit_max",
111 		.data		= &sysctl_speed_limit_max,
112 		.maxlen		= sizeof(int),
113 		.mode		= S_IRUGO|S_IWUSR,
114 		.proc_handler	= &proc_dointvec,
115 	},
116 	{ .ctl_name = 0 }
117 };
118 
119 static ctl_table raid_dir_table[] = {
120 	{
121 		.ctl_name	= DEV_RAID,
122 		.procname	= "raid",
123 		.maxlen		= 0,
124 		.mode		= S_IRUGO|S_IXUGO,
125 		.child		= raid_table,
126 	},
127 	{ .ctl_name = 0 }
128 };
129 
130 static ctl_table raid_root_table[] = {
131 	{
132 		.ctl_name	= CTL_DEV,
133 		.procname	= "dev",
134 		.maxlen		= 0,
135 		.mode		= 0555,
136 		.child		= raid_dir_table,
137 	},
138 	{ .ctl_name = 0 }
139 };
140 
141 static struct block_device_operations md_fops;
142 
143 static int start_readonly;
144 
145 /*
146  * We have a system wide 'event count' that is incremented
147  * on any 'interesting' event, and readers of /proc/mdstat
148  * can use 'poll' or 'select' to find out when the event
149  * count increases.
150  *
151  * Events are:
152  *  start array, stop array, error, add device, remove device,
153  *  start build, activate spare
154  */
155 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
156 static atomic_t md_event_count;
157 void md_new_event(mddev_t *mddev)
158 {
159 	atomic_inc(&md_event_count);
160 	wake_up(&md_event_waiters);
161 }
162 EXPORT_SYMBOL_GPL(md_new_event);
163 
164 /* Alternate version that can be called from interrupts
165  * when calling sysfs_notify isn't needed.
166  */
167 static void md_new_event_inintr(mddev_t *mddev)
168 {
169 	atomic_inc(&md_event_count);
170 	wake_up(&md_event_waiters);
171 }
172 
173 /*
174  * Enables to iterate over all existing md arrays
175  * all_mddevs_lock protects this list.
176  */
177 static LIST_HEAD(all_mddevs);
178 static DEFINE_SPINLOCK(all_mddevs_lock);
179 
180 
181 /*
182  * iterates through all used mddevs in the system.
183  * We take care to grab the all_mddevs_lock whenever navigating
184  * the list, and to always hold a refcount when unlocked.
185  * Any code which breaks out of this loop while own
186  * a reference to the current mddev and must mddev_put it.
187  */
188 #define for_each_mddev(mddev,tmp)					\
189 									\
190 	for (({ spin_lock(&all_mddevs_lock); 				\
191 		tmp = all_mddevs.next;					\
192 		mddev = NULL;});					\
193 	     ({ if (tmp != &all_mddevs)					\
194 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
195 		spin_unlock(&all_mddevs_lock);				\
196 		if (mddev) mddev_put(mddev);				\
197 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
198 		tmp != &all_mddevs;});					\
199 	     ({ spin_lock(&all_mddevs_lock);				\
200 		tmp = tmp->next;})					\
201 		)
202 
203 
204 /* Rather than calling directly into the personality make_request function,
205  * IO requests come here first so that we can check if the device is
206  * being suspended pending a reconfiguration.
207  * We hold a refcount over the call to ->make_request.  By the time that
208  * call has finished, the bio has been linked into some internal structure
209  * and so is visible to ->quiesce(), so we don't need the refcount any more.
210  */
211 static int md_make_request(struct request_queue *q, struct bio *bio)
212 {
213 	mddev_t *mddev = q->queuedata;
214 	int rv;
215 	if (mddev == NULL || mddev->pers == NULL) {
216 		bio_io_error(bio);
217 		return 0;
218 	}
219 	rcu_read_lock();
220 	if (mddev->suspended) {
221 		DEFINE_WAIT(__wait);
222 		for (;;) {
223 			prepare_to_wait(&mddev->sb_wait, &__wait,
224 					TASK_UNINTERRUPTIBLE);
225 			if (!mddev->suspended)
226 				break;
227 			rcu_read_unlock();
228 			schedule();
229 			rcu_read_lock();
230 		}
231 		finish_wait(&mddev->sb_wait, &__wait);
232 	}
233 	atomic_inc(&mddev->active_io);
234 	rcu_read_unlock();
235 	rv = mddev->pers->make_request(q, bio);
236 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
237 		wake_up(&mddev->sb_wait);
238 
239 	return rv;
240 }
241 
242 static void mddev_suspend(mddev_t *mddev)
243 {
244 	BUG_ON(mddev->suspended);
245 	mddev->suspended = 1;
246 	synchronize_rcu();
247 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
248 	mddev->pers->quiesce(mddev, 1);
249 	md_unregister_thread(mddev->thread);
250 	mddev->thread = NULL;
251 	/* we now know that no code is executing in the personality module,
252 	 * except possibly the tail end of a ->bi_end_io function, but that
253 	 * is certain to complete before the module has a chance to get
254 	 * unloaded
255 	 */
256 }
257 
258 static void mddev_resume(mddev_t *mddev)
259 {
260 	mddev->suspended = 0;
261 	wake_up(&mddev->sb_wait);
262 	mddev->pers->quiesce(mddev, 0);
263 }
264 
265 
266 static inline mddev_t *mddev_get(mddev_t *mddev)
267 {
268 	atomic_inc(&mddev->active);
269 	return mddev;
270 }
271 
272 static void mddev_delayed_delete(struct work_struct *ws);
273 
274 static void mddev_put(mddev_t *mddev)
275 {
276 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
277 		return;
278 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
279 	    !mddev->hold_active) {
280 		list_del(&mddev->all_mddevs);
281 		if (mddev->gendisk) {
282 			/* we did a probe so need to clean up.
283 			 * Call schedule_work inside the spinlock
284 			 * so that flush_scheduled_work() after
285 			 * mddev_find will succeed in waiting for the
286 			 * work to be done.
287 			 */
288 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
289 			schedule_work(&mddev->del_work);
290 		} else
291 			kfree(mddev);
292 	}
293 	spin_unlock(&all_mddevs_lock);
294 }
295 
296 static mddev_t * mddev_find(dev_t unit)
297 {
298 	mddev_t *mddev, *new = NULL;
299 
300  retry:
301 	spin_lock(&all_mddevs_lock);
302 
303 	if (unit) {
304 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
305 			if (mddev->unit == unit) {
306 				mddev_get(mddev);
307 				spin_unlock(&all_mddevs_lock);
308 				kfree(new);
309 				return mddev;
310 			}
311 
312 		if (new) {
313 			list_add(&new->all_mddevs, &all_mddevs);
314 			spin_unlock(&all_mddevs_lock);
315 			new->hold_active = UNTIL_IOCTL;
316 			return new;
317 		}
318 	} else if (new) {
319 		/* find an unused unit number */
320 		static int next_minor = 512;
321 		int start = next_minor;
322 		int is_free = 0;
323 		int dev = 0;
324 		while (!is_free) {
325 			dev = MKDEV(MD_MAJOR, next_minor);
326 			next_minor++;
327 			if (next_minor > MINORMASK)
328 				next_minor = 0;
329 			if (next_minor == start) {
330 				/* Oh dear, all in use. */
331 				spin_unlock(&all_mddevs_lock);
332 				kfree(new);
333 				return NULL;
334 			}
335 
336 			is_free = 1;
337 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
338 				if (mddev->unit == dev) {
339 					is_free = 0;
340 					break;
341 				}
342 		}
343 		new->unit = dev;
344 		new->md_minor = MINOR(dev);
345 		new->hold_active = UNTIL_STOP;
346 		list_add(&new->all_mddevs, &all_mddevs);
347 		spin_unlock(&all_mddevs_lock);
348 		return new;
349 	}
350 	spin_unlock(&all_mddevs_lock);
351 
352 	new = kzalloc(sizeof(*new), GFP_KERNEL);
353 	if (!new)
354 		return NULL;
355 
356 	new->unit = unit;
357 	if (MAJOR(unit) == MD_MAJOR)
358 		new->md_minor = MINOR(unit);
359 	else
360 		new->md_minor = MINOR(unit) >> MdpMinorShift;
361 
362 	mutex_init(&new->reconfig_mutex);
363 	INIT_LIST_HEAD(&new->disks);
364 	INIT_LIST_HEAD(&new->all_mddevs);
365 	init_timer(&new->safemode_timer);
366 	atomic_set(&new->active, 1);
367 	atomic_set(&new->openers, 0);
368 	atomic_set(&new->active_io, 0);
369 	spin_lock_init(&new->write_lock);
370 	init_waitqueue_head(&new->sb_wait);
371 	init_waitqueue_head(&new->recovery_wait);
372 	new->reshape_position = MaxSector;
373 	new->resync_min = 0;
374 	new->resync_max = MaxSector;
375 	new->level = LEVEL_NONE;
376 
377 	goto retry;
378 }
379 
380 static inline int mddev_lock(mddev_t * mddev)
381 {
382 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
383 }
384 
385 static inline int mddev_is_locked(mddev_t *mddev)
386 {
387 	return mutex_is_locked(&mddev->reconfig_mutex);
388 }
389 
390 static inline int mddev_trylock(mddev_t * mddev)
391 {
392 	return mutex_trylock(&mddev->reconfig_mutex);
393 }
394 
395 static inline void mddev_unlock(mddev_t * mddev)
396 {
397 	mutex_unlock(&mddev->reconfig_mutex);
398 
399 	md_wakeup_thread(mddev->thread);
400 }
401 
402 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
403 {
404 	mdk_rdev_t *rdev;
405 
406 	list_for_each_entry(rdev, &mddev->disks, same_set)
407 		if (rdev->desc_nr == nr)
408 			return rdev;
409 
410 	return NULL;
411 }
412 
413 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
414 {
415 	mdk_rdev_t *rdev;
416 
417 	list_for_each_entry(rdev, &mddev->disks, same_set)
418 		if (rdev->bdev->bd_dev == dev)
419 			return rdev;
420 
421 	return NULL;
422 }
423 
424 static struct mdk_personality *find_pers(int level, char *clevel)
425 {
426 	struct mdk_personality *pers;
427 	list_for_each_entry(pers, &pers_list, list) {
428 		if (level != LEVEL_NONE && pers->level == level)
429 			return pers;
430 		if (strcmp(pers->name, clevel)==0)
431 			return pers;
432 	}
433 	return NULL;
434 }
435 
436 /* return the offset of the super block in 512byte sectors */
437 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
438 {
439 	sector_t num_sectors = bdev->bd_inode->i_size / 512;
440 	return MD_NEW_SIZE_SECTORS(num_sectors);
441 }
442 
443 static int alloc_disk_sb(mdk_rdev_t * rdev)
444 {
445 	if (rdev->sb_page)
446 		MD_BUG();
447 
448 	rdev->sb_page = alloc_page(GFP_KERNEL);
449 	if (!rdev->sb_page) {
450 		printk(KERN_ALERT "md: out of memory.\n");
451 		return -ENOMEM;
452 	}
453 
454 	return 0;
455 }
456 
457 static void free_disk_sb(mdk_rdev_t * rdev)
458 {
459 	if (rdev->sb_page) {
460 		put_page(rdev->sb_page);
461 		rdev->sb_loaded = 0;
462 		rdev->sb_page = NULL;
463 		rdev->sb_start = 0;
464 		rdev->sectors = 0;
465 	}
466 }
467 
468 
469 static void super_written(struct bio *bio, int error)
470 {
471 	mdk_rdev_t *rdev = bio->bi_private;
472 	mddev_t *mddev = rdev->mddev;
473 
474 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
475 		printk("md: super_written gets error=%d, uptodate=%d\n",
476 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
477 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
478 		md_error(mddev, rdev);
479 	}
480 
481 	if (atomic_dec_and_test(&mddev->pending_writes))
482 		wake_up(&mddev->sb_wait);
483 	bio_put(bio);
484 }
485 
486 static void super_written_barrier(struct bio *bio, int error)
487 {
488 	struct bio *bio2 = bio->bi_private;
489 	mdk_rdev_t *rdev = bio2->bi_private;
490 	mddev_t *mddev = rdev->mddev;
491 
492 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
493 	    error == -EOPNOTSUPP) {
494 		unsigned long flags;
495 		/* barriers don't appear to be supported :-( */
496 		set_bit(BarriersNotsupp, &rdev->flags);
497 		mddev->barriers_work = 0;
498 		spin_lock_irqsave(&mddev->write_lock, flags);
499 		bio2->bi_next = mddev->biolist;
500 		mddev->biolist = bio2;
501 		spin_unlock_irqrestore(&mddev->write_lock, flags);
502 		wake_up(&mddev->sb_wait);
503 		bio_put(bio);
504 	} else {
505 		bio_put(bio2);
506 		bio->bi_private = rdev;
507 		super_written(bio, error);
508 	}
509 }
510 
511 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
512 		   sector_t sector, int size, struct page *page)
513 {
514 	/* write first size bytes of page to sector of rdev
515 	 * Increment mddev->pending_writes before returning
516 	 * and decrement it on completion, waking up sb_wait
517 	 * if zero is reached.
518 	 * If an error occurred, call md_error
519 	 *
520 	 * As we might need to resubmit the request if BIO_RW_BARRIER
521 	 * causes ENOTSUPP, we allocate a spare bio...
522 	 */
523 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
524 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNCIO) | (1<<BIO_RW_UNPLUG);
525 
526 	bio->bi_bdev = rdev->bdev;
527 	bio->bi_sector = sector;
528 	bio_add_page(bio, page, size, 0);
529 	bio->bi_private = rdev;
530 	bio->bi_end_io = super_written;
531 	bio->bi_rw = rw;
532 
533 	atomic_inc(&mddev->pending_writes);
534 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
535 		struct bio *rbio;
536 		rw |= (1<<BIO_RW_BARRIER);
537 		rbio = bio_clone(bio, GFP_NOIO);
538 		rbio->bi_private = bio;
539 		rbio->bi_end_io = super_written_barrier;
540 		submit_bio(rw, rbio);
541 	} else
542 		submit_bio(rw, bio);
543 }
544 
545 void md_super_wait(mddev_t *mddev)
546 {
547 	/* wait for all superblock writes that were scheduled to complete.
548 	 * if any had to be retried (due to BARRIER problems), retry them
549 	 */
550 	DEFINE_WAIT(wq);
551 	for(;;) {
552 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
553 		if (atomic_read(&mddev->pending_writes)==0)
554 			break;
555 		while (mddev->biolist) {
556 			struct bio *bio;
557 			spin_lock_irq(&mddev->write_lock);
558 			bio = mddev->biolist;
559 			mddev->biolist = bio->bi_next ;
560 			bio->bi_next = NULL;
561 			spin_unlock_irq(&mddev->write_lock);
562 			submit_bio(bio->bi_rw, bio);
563 		}
564 		schedule();
565 	}
566 	finish_wait(&mddev->sb_wait, &wq);
567 }
568 
569 static void bi_complete(struct bio *bio, int error)
570 {
571 	complete((struct completion*)bio->bi_private);
572 }
573 
574 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
575 		   struct page *page, int rw)
576 {
577 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
578 	struct completion event;
579 	int ret;
580 
581 	rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
582 
583 	bio->bi_bdev = bdev;
584 	bio->bi_sector = sector;
585 	bio_add_page(bio, page, size, 0);
586 	init_completion(&event);
587 	bio->bi_private = &event;
588 	bio->bi_end_io = bi_complete;
589 	submit_bio(rw, bio);
590 	wait_for_completion(&event);
591 
592 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
593 	bio_put(bio);
594 	return ret;
595 }
596 EXPORT_SYMBOL_GPL(sync_page_io);
597 
598 static int read_disk_sb(mdk_rdev_t * rdev, int size)
599 {
600 	char b[BDEVNAME_SIZE];
601 	if (!rdev->sb_page) {
602 		MD_BUG();
603 		return -EINVAL;
604 	}
605 	if (rdev->sb_loaded)
606 		return 0;
607 
608 
609 	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
610 		goto fail;
611 	rdev->sb_loaded = 1;
612 	return 0;
613 
614 fail:
615 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
616 		bdevname(rdev->bdev,b));
617 	return -EINVAL;
618 }
619 
620 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
621 {
622 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
623 		sb1->set_uuid1 == sb2->set_uuid1 &&
624 		sb1->set_uuid2 == sb2->set_uuid2 &&
625 		sb1->set_uuid3 == sb2->set_uuid3;
626 }
627 
628 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
629 {
630 	int ret;
631 	mdp_super_t *tmp1, *tmp2;
632 
633 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
634 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
635 
636 	if (!tmp1 || !tmp2) {
637 		ret = 0;
638 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
639 		goto abort;
640 	}
641 
642 	*tmp1 = *sb1;
643 	*tmp2 = *sb2;
644 
645 	/*
646 	 * nr_disks is not constant
647 	 */
648 	tmp1->nr_disks = 0;
649 	tmp2->nr_disks = 0;
650 
651 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
652 abort:
653 	kfree(tmp1);
654 	kfree(tmp2);
655 	return ret;
656 }
657 
658 
659 static u32 md_csum_fold(u32 csum)
660 {
661 	csum = (csum & 0xffff) + (csum >> 16);
662 	return (csum & 0xffff) + (csum >> 16);
663 }
664 
665 static unsigned int calc_sb_csum(mdp_super_t * sb)
666 {
667 	u64 newcsum = 0;
668 	u32 *sb32 = (u32*)sb;
669 	int i;
670 	unsigned int disk_csum, csum;
671 
672 	disk_csum = sb->sb_csum;
673 	sb->sb_csum = 0;
674 
675 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
676 		newcsum += sb32[i];
677 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
678 
679 
680 #ifdef CONFIG_ALPHA
681 	/* This used to use csum_partial, which was wrong for several
682 	 * reasons including that different results are returned on
683 	 * different architectures.  It isn't critical that we get exactly
684 	 * the same return value as before (we always csum_fold before
685 	 * testing, and that removes any differences).  However as we
686 	 * know that csum_partial always returned a 16bit value on
687 	 * alphas, do a fold to maximise conformity to previous behaviour.
688 	 */
689 	sb->sb_csum = md_csum_fold(disk_csum);
690 #else
691 	sb->sb_csum = disk_csum;
692 #endif
693 	return csum;
694 }
695 
696 
697 /*
698  * Handle superblock details.
699  * We want to be able to handle multiple superblock formats
700  * so we have a common interface to them all, and an array of
701  * different handlers.
702  * We rely on user-space to write the initial superblock, and support
703  * reading and updating of superblocks.
704  * Interface methods are:
705  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
706  *      loads and validates a superblock on dev.
707  *      if refdev != NULL, compare superblocks on both devices
708  *    Return:
709  *      0 - dev has a superblock that is compatible with refdev
710  *      1 - dev has a superblock that is compatible and newer than refdev
711  *          so dev should be used as the refdev in future
712  *     -EINVAL superblock incompatible or invalid
713  *     -othererror e.g. -EIO
714  *
715  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
716  *      Verify that dev is acceptable into mddev.
717  *       The first time, mddev->raid_disks will be 0, and data from
718  *       dev should be merged in.  Subsequent calls check that dev
719  *       is new enough.  Return 0 or -EINVAL
720  *
721  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
722  *     Update the superblock for rdev with data in mddev
723  *     This does not write to disc.
724  *
725  */
726 
727 struct super_type  {
728 	char		    *name;
729 	struct module	    *owner;
730 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
731 					  int minor_version);
732 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
733 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
734 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
735 						sector_t num_sectors);
736 };
737 
738 /*
739  * Check that the given mddev has no bitmap.
740  *
741  * This function is called from the run method of all personalities that do not
742  * support bitmaps. It prints an error message and returns non-zero if mddev
743  * has a bitmap. Otherwise, it returns 0.
744  *
745  */
746 int md_check_no_bitmap(mddev_t *mddev)
747 {
748 	if (!mddev->bitmap_file && !mddev->bitmap_offset)
749 		return 0;
750 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
751 		mdname(mddev), mddev->pers->name);
752 	return 1;
753 }
754 EXPORT_SYMBOL(md_check_no_bitmap);
755 
756 /*
757  * load_super for 0.90.0
758  */
759 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
760 {
761 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
762 	mdp_super_t *sb;
763 	int ret;
764 
765 	/*
766 	 * Calculate the position of the superblock (512byte sectors),
767 	 * it's at the end of the disk.
768 	 *
769 	 * It also happens to be a multiple of 4Kb.
770 	 */
771 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
772 
773 	ret = read_disk_sb(rdev, MD_SB_BYTES);
774 	if (ret) return ret;
775 
776 	ret = -EINVAL;
777 
778 	bdevname(rdev->bdev, b);
779 	sb = (mdp_super_t*)page_address(rdev->sb_page);
780 
781 	if (sb->md_magic != MD_SB_MAGIC) {
782 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
783 		       b);
784 		goto abort;
785 	}
786 
787 	if (sb->major_version != 0 ||
788 	    sb->minor_version < 90 ||
789 	    sb->minor_version > 91) {
790 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
791 			sb->major_version, sb->minor_version,
792 			b);
793 		goto abort;
794 	}
795 
796 	if (sb->raid_disks <= 0)
797 		goto abort;
798 
799 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
800 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
801 			b);
802 		goto abort;
803 	}
804 
805 	rdev->preferred_minor = sb->md_minor;
806 	rdev->data_offset = 0;
807 	rdev->sb_size = MD_SB_BYTES;
808 
809 	if (sb->level == LEVEL_MULTIPATH)
810 		rdev->desc_nr = -1;
811 	else
812 		rdev->desc_nr = sb->this_disk.number;
813 
814 	if (!refdev) {
815 		ret = 1;
816 	} else {
817 		__u64 ev1, ev2;
818 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
819 		if (!uuid_equal(refsb, sb)) {
820 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
821 				b, bdevname(refdev->bdev,b2));
822 			goto abort;
823 		}
824 		if (!sb_equal(refsb, sb)) {
825 			printk(KERN_WARNING "md: %s has same UUID"
826 			       " but different superblock to %s\n",
827 			       b, bdevname(refdev->bdev, b2));
828 			goto abort;
829 		}
830 		ev1 = md_event(sb);
831 		ev2 = md_event(refsb);
832 		if (ev1 > ev2)
833 			ret = 1;
834 		else
835 			ret = 0;
836 	}
837 	rdev->sectors = rdev->sb_start;
838 
839 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
840 		/* "this cannot possibly happen" ... */
841 		ret = -EINVAL;
842 
843  abort:
844 	return ret;
845 }
846 
847 /*
848  * validate_super for 0.90.0
849  */
850 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
851 {
852 	mdp_disk_t *desc;
853 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
854 	__u64 ev1 = md_event(sb);
855 
856 	rdev->raid_disk = -1;
857 	clear_bit(Faulty, &rdev->flags);
858 	clear_bit(In_sync, &rdev->flags);
859 	clear_bit(WriteMostly, &rdev->flags);
860 	clear_bit(BarriersNotsupp, &rdev->flags);
861 
862 	if (mddev->raid_disks == 0) {
863 		mddev->major_version = 0;
864 		mddev->minor_version = sb->minor_version;
865 		mddev->patch_version = sb->patch_version;
866 		mddev->external = 0;
867 		mddev->chunk_sectors = sb->chunk_size >> 9;
868 		mddev->ctime = sb->ctime;
869 		mddev->utime = sb->utime;
870 		mddev->level = sb->level;
871 		mddev->clevel[0] = 0;
872 		mddev->layout = sb->layout;
873 		mddev->raid_disks = sb->raid_disks;
874 		mddev->dev_sectors = sb->size * 2;
875 		mddev->events = ev1;
876 		mddev->bitmap_offset = 0;
877 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
878 
879 		if (mddev->minor_version >= 91) {
880 			mddev->reshape_position = sb->reshape_position;
881 			mddev->delta_disks = sb->delta_disks;
882 			mddev->new_level = sb->new_level;
883 			mddev->new_layout = sb->new_layout;
884 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
885 		} else {
886 			mddev->reshape_position = MaxSector;
887 			mddev->delta_disks = 0;
888 			mddev->new_level = mddev->level;
889 			mddev->new_layout = mddev->layout;
890 			mddev->new_chunk_sectors = mddev->chunk_sectors;
891 		}
892 
893 		if (sb->state & (1<<MD_SB_CLEAN))
894 			mddev->recovery_cp = MaxSector;
895 		else {
896 			if (sb->events_hi == sb->cp_events_hi &&
897 				sb->events_lo == sb->cp_events_lo) {
898 				mddev->recovery_cp = sb->recovery_cp;
899 			} else
900 				mddev->recovery_cp = 0;
901 		}
902 
903 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
904 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
905 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
906 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
907 
908 		mddev->max_disks = MD_SB_DISKS;
909 
910 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
911 		    mddev->bitmap_file == NULL)
912 			mddev->bitmap_offset = mddev->default_bitmap_offset;
913 
914 	} else if (mddev->pers == NULL) {
915 		/* Insist on good event counter while assembling */
916 		++ev1;
917 		if (ev1 < mddev->events)
918 			return -EINVAL;
919 	} else if (mddev->bitmap) {
920 		/* if adding to array with a bitmap, then we can accept an
921 		 * older device ... but not too old.
922 		 */
923 		if (ev1 < mddev->bitmap->events_cleared)
924 			return 0;
925 	} else {
926 		if (ev1 < mddev->events)
927 			/* just a hot-add of a new device, leave raid_disk at -1 */
928 			return 0;
929 	}
930 
931 	if (mddev->level != LEVEL_MULTIPATH) {
932 		desc = sb->disks + rdev->desc_nr;
933 
934 		if (desc->state & (1<<MD_DISK_FAULTY))
935 			set_bit(Faulty, &rdev->flags);
936 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
937 			    desc->raid_disk < mddev->raid_disks */) {
938 			set_bit(In_sync, &rdev->flags);
939 			rdev->raid_disk = desc->raid_disk;
940 		}
941 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
942 			set_bit(WriteMostly, &rdev->flags);
943 	} else /* MULTIPATH are always insync */
944 		set_bit(In_sync, &rdev->flags);
945 	return 0;
946 }
947 
948 /*
949  * sync_super for 0.90.0
950  */
951 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
952 {
953 	mdp_super_t *sb;
954 	mdk_rdev_t *rdev2;
955 	int next_spare = mddev->raid_disks;
956 
957 
958 	/* make rdev->sb match mddev data..
959 	 *
960 	 * 1/ zero out disks
961 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
962 	 * 3/ any empty disks < next_spare become removed
963 	 *
964 	 * disks[0] gets initialised to REMOVED because
965 	 * we cannot be sure from other fields if it has
966 	 * been initialised or not.
967 	 */
968 	int i;
969 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
970 
971 	rdev->sb_size = MD_SB_BYTES;
972 
973 	sb = (mdp_super_t*)page_address(rdev->sb_page);
974 
975 	memset(sb, 0, sizeof(*sb));
976 
977 	sb->md_magic = MD_SB_MAGIC;
978 	sb->major_version = mddev->major_version;
979 	sb->patch_version = mddev->patch_version;
980 	sb->gvalid_words  = 0; /* ignored */
981 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
982 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
983 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
984 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
985 
986 	sb->ctime = mddev->ctime;
987 	sb->level = mddev->level;
988 	sb->size = mddev->dev_sectors / 2;
989 	sb->raid_disks = mddev->raid_disks;
990 	sb->md_minor = mddev->md_minor;
991 	sb->not_persistent = 0;
992 	sb->utime = mddev->utime;
993 	sb->state = 0;
994 	sb->events_hi = (mddev->events>>32);
995 	sb->events_lo = (u32)mddev->events;
996 
997 	if (mddev->reshape_position == MaxSector)
998 		sb->minor_version = 90;
999 	else {
1000 		sb->minor_version = 91;
1001 		sb->reshape_position = mddev->reshape_position;
1002 		sb->new_level = mddev->new_level;
1003 		sb->delta_disks = mddev->delta_disks;
1004 		sb->new_layout = mddev->new_layout;
1005 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1006 	}
1007 	mddev->minor_version = sb->minor_version;
1008 	if (mddev->in_sync)
1009 	{
1010 		sb->recovery_cp = mddev->recovery_cp;
1011 		sb->cp_events_hi = (mddev->events>>32);
1012 		sb->cp_events_lo = (u32)mddev->events;
1013 		if (mddev->recovery_cp == MaxSector)
1014 			sb->state = (1<< MD_SB_CLEAN);
1015 	} else
1016 		sb->recovery_cp = 0;
1017 
1018 	sb->layout = mddev->layout;
1019 	sb->chunk_size = mddev->chunk_sectors << 9;
1020 
1021 	if (mddev->bitmap && mddev->bitmap_file == NULL)
1022 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1023 
1024 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1025 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1026 		mdp_disk_t *d;
1027 		int desc_nr;
1028 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
1029 		    && !test_bit(Faulty, &rdev2->flags))
1030 			desc_nr = rdev2->raid_disk;
1031 		else
1032 			desc_nr = next_spare++;
1033 		rdev2->desc_nr = desc_nr;
1034 		d = &sb->disks[rdev2->desc_nr];
1035 		nr_disks++;
1036 		d->number = rdev2->desc_nr;
1037 		d->major = MAJOR(rdev2->bdev->bd_dev);
1038 		d->minor = MINOR(rdev2->bdev->bd_dev);
1039 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
1040 		    && !test_bit(Faulty, &rdev2->flags))
1041 			d->raid_disk = rdev2->raid_disk;
1042 		else
1043 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1044 		if (test_bit(Faulty, &rdev2->flags))
1045 			d->state = (1<<MD_DISK_FAULTY);
1046 		else if (test_bit(In_sync, &rdev2->flags)) {
1047 			d->state = (1<<MD_DISK_ACTIVE);
1048 			d->state |= (1<<MD_DISK_SYNC);
1049 			active++;
1050 			working++;
1051 		} else {
1052 			d->state = 0;
1053 			spare++;
1054 			working++;
1055 		}
1056 		if (test_bit(WriteMostly, &rdev2->flags))
1057 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1058 	}
1059 	/* now set the "removed" and "faulty" bits on any missing devices */
1060 	for (i=0 ; i < mddev->raid_disks ; i++) {
1061 		mdp_disk_t *d = &sb->disks[i];
1062 		if (d->state == 0 && d->number == 0) {
1063 			d->number = i;
1064 			d->raid_disk = i;
1065 			d->state = (1<<MD_DISK_REMOVED);
1066 			d->state |= (1<<MD_DISK_FAULTY);
1067 			failed++;
1068 		}
1069 	}
1070 	sb->nr_disks = nr_disks;
1071 	sb->active_disks = active;
1072 	sb->working_disks = working;
1073 	sb->failed_disks = failed;
1074 	sb->spare_disks = spare;
1075 
1076 	sb->this_disk = sb->disks[rdev->desc_nr];
1077 	sb->sb_csum = calc_sb_csum(sb);
1078 }
1079 
1080 /*
1081  * rdev_size_change for 0.90.0
1082  */
1083 static unsigned long long
1084 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1085 {
1086 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1087 		return 0; /* component must fit device */
1088 	if (rdev->mddev->bitmap_offset)
1089 		return 0; /* can't move bitmap */
1090 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1091 	if (!num_sectors || num_sectors > rdev->sb_start)
1092 		num_sectors = rdev->sb_start;
1093 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1094 		       rdev->sb_page);
1095 	md_super_wait(rdev->mddev);
1096 	return num_sectors / 2; /* kB for sysfs */
1097 }
1098 
1099 
1100 /*
1101  * version 1 superblock
1102  */
1103 
1104 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1105 {
1106 	__le32 disk_csum;
1107 	u32 csum;
1108 	unsigned long long newcsum;
1109 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1110 	__le32 *isuper = (__le32*)sb;
1111 	int i;
1112 
1113 	disk_csum = sb->sb_csum;
1114 	sb->sb_csum = 0;
1115 	newcsum = 0;
1116 	for (i=0; size>=4; size -= 4 )
1117 		newcsum += le32_to_cpu(*isuper++);
1118 
1119 	if (size == 2)
1120 		newcsum += le16_to_cpu(*(__le16*) isuper);
1121 
1122 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1123 	sb->sb_csum = disk_csum;
1124 	return cpu_to_le32(csum);
1125 }
1126 
1127 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1128 {
1129 	struct mdp_superblock_1 *sb;
1130 	int ret;
1131 	sector_t sb_start;
1132 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1133 	int bmask;
1134 
1135 	/*
1136 	 * Calculate the position of the superblock in 512byte sectors.
1137 	 * It is always aligned to a 4K boundary and
1138 	 * depeding on minor_version, it can be:
1139 	 * 0: At least 8K, but less than 12K, from end of device
1140 	 * 1: At start of device
1141 	 * 2: 4K from start of device.
1142 	 */
1143 	switch(minor_version) {
1144 	case 0:
1145 		sb_start = rdev->bdev->bd_inode->i_size >> 9;
1146 		sb_start -= 8*2;
1147 		sb_start &= ~(sector_t)(4*2-1);
1148 		break;
1149 	case 1:
1150 		sb_start = 0;
1151 		break;
1152 	case 2:
1153 		sb_start = 8;
1154 		break;
1155 	default:
1156 		return -EINVAL;
1157 	}
1158 	rdev->sb_start = sb_start;
1159 
1160 	/* superblock is rarely larger than 1K, but it can be larger,
1161 	 * and it is safe to read 4k, so we do that
1162 	 */
1163 	ret = read_disk_sb(rdev, 4096);
1164 	if (ret) return ret;
1165 
1166 
1167 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1168 
1169 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1170 	    sb->major_version != cpu_to_le32(1) ||
1171 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1172 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1173 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1174 		return -EINVAL;
1175 
1176 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1177 		printk("md: invalid superblock checksum on %s\n",
1178 			bdevname(rdev->bdev,b));
1179 		return -EINVAL;
1180 	}
1181 	if (le64_to_cpu(sb->data_size) < 10) {
1182 		printk("md: data_size too small on %s\n",
1183 		       bdevname(rdev->bdev,b));
1184 		return -EINVAL;
1185 	}
1186 
1187 	rdev->preferred_minor = 0xffff;
1188 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1189 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1190 
1191 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1192 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1193 	if (rdev->sb_size & bmask)
1194 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1195 
1196 	if (minor_version
1197 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1198 		return -EINVAL;
1199 
1200 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1201 		rdev->desc_nr = -1;
1202 	else
1203 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1204 
1205 	if (!refdev) {
1206 		ret = 1;
1207 	} else {
1208 		__u64 ev1, ev2;
1209 		struct mdp_superblock_1 *refsb =
1210 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1211 
1212 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1213 		    sb->level != refsb->level ||
1214 		    sb->layout != refsb->layout ||
1215 		    sb->chunksize != refsb->chunksize) {
1216 			printk(KERN_WARNING "md: %s has strangely different"
1217 				" superblock to %s\n",
1218 				bdevname(rdev->bdev,b),
1219 				bdevname(refdev->bdev,b2));
1220 			return -EINVAL;
1221 		}
1222 		ev1 = le64_to_cpu(sb->events);
1223 		ev2 = le64_to_cpu(refsb->events);
1224 
1225 		if (ev1 > ev2)
1226 			ret = 1;
1227 		else
1228 			ret = 0;
1229 	}
1230 	if (minor_version)
1231 		rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
1232 			le64_to_cpu(sb->data_offset);
1233 	else
1234 		rdev->sectors = rdev->sb_start;
1235 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1236 		return -EINVAL;
1237 	rdev->sectors = le64_to_cpu(sb->data_size);
1238 	if (le64_to_cpu(sb->size) > rdev->sectors)
1239 		return -EINVAL;
1240 	return ret;
1241 }
1242 
1243 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1244 {
1245 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1246 	__u64 ev1 = le64_to_cpu(sb->events);
1247 
1248 	rdev->raid_disk = -1;
1249 	clear_bit(Faulty, &rdev->flags);
1250 	clear_bit(In_sync, &rdev->flags);
1251 	clear_bit(WriteMostly, &rdev->flags);
1252 	clear_bit(BarriersNotsupp, &rdev->flags);
1253 
1254 	if (mddev->raid_disks == 0) {
1255 		mddev->major_version = 1;
1256 		mddev->patch_version = 0;
1257 		mddev->external = 0;
1258 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1259 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1260 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1261 		mddev->level = le32_to_cpu(sb->level);
1262 		mddev->clevel[0] = 0;
1263 		mddev->layout = le32_to_cpu(sb->layout);
1264 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1265 		mddev->dev_sectors = le64_to_cpu(sb->size);
1266 		mddev->events = ev1;
1267 		mddev->bitmap_offset = 0;
1268 		mddev->default_bitmap_offset = 1024 >> 9;
1269 
1270 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1271 		memcpy(mddev->uuid, sb->set_uuid, 16);
1272 
1273 		mddev->max_disks =  (4096-256)/2;
1274 
1275 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1276 		    mddev->bitmap_file == NULL )
1277 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1278 
1279 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1280 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1281 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1282 			mddev->new_level = le32_to_cpu(sb->new_level);
1283 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1284 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1285 		} else {
1286 			mddev->reshape_position = MaxSector;
1287 			mddev->delta_disks = 0;
1288 			mddev->new_level = mddev->level;
1289 			mddev->new_layout = mddev->layout;
1290 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1291 		}
1292 
1293 	} else if (mddev->pers == NULL) {
1294 		/* Insist of good event counter while assembling */
1295 		++ev1;
1296 		if (ev1 < mddev->events)
1297 			return -EINVAL;
1298 	} else if (mddev->bitmap) {
1299 		/* If adding to array with a bitmap, then we can accept an
1300 		 * older device, but not too old.
1301 		 */
1302 		if (ev1 < mddev->bitmap->events_cleared)
1303 			return 0;
1304 	} else {
1305 		if (ev1 < mddev->events)
1306 			/* just a hot-add of a new device, leave raid_disk at -1 */
1307 			return 0;
1308 	}
1309 	if (mddev->level != LEVEL_MULTIPATH) {
1310 		int role;
1311 		role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1312 		switch(role) {
1313 		case 0xffff: /* spare */
1314 			break;
1315 		case 0xfffe: /* faulty */
1316 			set_bit(Faulty, &rdev->flags);
1317 			break;
1318 		default:
1319 			if ((le32_to_cpu(sb->feature_map) &
1320 			     MD_FEATURE_RECOVERY_OFFSET))
1321 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1322 			else
1323 				set_bit(In_sync, &rdev->flags);
1324 			rdev->raid_disk = role;
1325 			break;
1326 		}
1327 		if (sb->devflags & WriteMostly1)
1328 			set_bit(WriteMostly, &rdev->flags);
1329 	} else /* MULTIPATH are always insync */
1330 		set_bit(In_sync, &rdev->flags);
1331 
1332 	return 0;
1333 }
1334 
1335 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1336 {
1337 	struct mdp_superblock_1 *sb;
1338 	mdk_rdev_t *rdev2;
1339 	int max_dev, i;
1340 	/* make rdev->sb match mddev and rdev data. */
1341 
1342 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1343 
1344 	sb->feature_map = 0;
1345 	sb->pad0 = 0;
1346 	sb->recovery_offset = cpu_to_le64(0);
1347 	memset(sb->pad1, 0, sizeof(sb->pad1));
1348 	memset(sb->pad2, 0, sizeof(sb->pad2));
1349 	memset(sb->pad3, 0, sizeof(sb->pad3));
1350 
1351 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1352 	sb->events = cpu_to_le64(mddev->events);
1353 	if (mddev->in_sync)
1354 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1355 	else
1356 		sb->resync_offset = cpu_to_le64(0);
1357 
1358 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1359 
1360 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1361 	sb->size = cpu_to_le64(mddev->dev_sectors);
1362 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1363 	sb->level = cpu_to_le32(mddev->level);
1364 	sb->layout = cpu_to_le32(mddev->layout);
1365 
1366 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1367 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1368 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1369 	}
1370 
1371 	if (rdev->raid_disk >= 0 &&
1372 	    !test_bit(In_sync, &rdev->flags)) {
1373 		if (mddev->curr_resync_completed > rdev->recovery_offset)
1374 			rdev->recovery_offset = mddev->curr_resync_completed;
1375 		if (rdev->recovery_offset > 0) {
1376 			sb->feature_map |=
1377 				cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1378 			sb->recovery_offset =
1379 				cpu_to_le64(rdev->recovery_offset);
1380 		}
1381 	}
1382 
1383 	if (mddev->reshape_position != MaxSector) {
1384 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1385 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1386 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1387 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1388 		sb->new_level = cpu_to_le32(mddev->new_level);
1389 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1390 	}
1391 
1392 	max_dev = 0;
1393 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1394 		if (rdev2->desc_nr+1 > max_dev)
1395 			max_dev = rdev2->desc_nr+1;
1396 
1397 	if (max_dev > le32_to_cpu(sb->max_dev))
1398 		sb->max_dev = cpu_to_le32(max_dev);
1399 	for (i=0; i<max_dev;i++)
1400 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1401 
1402 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1403 		i = rdev2->desc_nr;
1404 		if (test_bit(Faulty, &rdev2->flags))
1405 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1406 		else if (test_bit(In_sync, &rdev2->flags))
1407 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1408 		else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
1409 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1410 		else
1411 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1412 	}
1413 
1414 	sb->sb_csum = calc_sb_1_csum(sb);
1415 }
1416 
1417 static unsigned long long
1418 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1419 {
1420 	struct mdp_superblock_1 *sb;
1421 	sector_t max_sectors;
1422 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1423 		return 0; /* component must fit device */
1424 	if (rdev->sb_start < rdev->data_offset) {
1425 		/* minor versions 1 and 2; superblock before data */
1426 		max_sectors = rdev->bdev->bd_inode->i_size >> 9;
1427 		max_sectors -= rdev->data_offset;
1428 		if (!num_sectors || num_sectors > max_sectors)
1429 			num_sectors = max_sectors;
1430 	} else if (rdev->mddev->bitmap_offset) {
1431 		/* minor version 0 with bitmap we can't move */
1432 		return 0;
1433 	} else {
1434 		/* minor version 0; superblock after data */
1435 		sector_t sb_start;
1436 		sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
1437 		sb_start &= ~(sector_t)(4*2 - 1);
1438 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1439 		if (!num_sectors || num_sectors > max_sectors)
1440 			num_sectors = max_sectors;
1441 		rdev->sb_start = sb_start;
1442 	}
1443 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1444 	sb->data_size = cpu_to_le64(num_sectors);
1445 	sb->super_offset = rdev->sb_start;
1446 	sb->sb_csum = calc_sb_1_csum(sb);
1447 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1448 		       rdev->sb_page);
1449 	md_super_wait(rdev->mddev);
1450 	return num_sectors / 2; /* kB for sysfs */
1451 }
1452 
1453 static struct super_type super_types[] = {
1454 	[0] = {
1455 		.name	= "0.90.0",
1456 		.owner	= THIS_MODULE,
1457 		.load_super	    = super_90_load,
1458 		.validate_super	    = super_90_validate,
1459 		.sync_super	    = super_90_sync,
1460 		.rdev_size_change   = super_90_rdev_size_change,
1461 	},
1462 	[1] = {
1463 		.name	= "md-1",
1464 		.owner	= THIS_MODULE,
1465 		.load_super	    = super_1_load,
1466 		.validate_super	    = super_1_validate,
1467 		.sync_super	    = super_1_sync,
1468 		.rdev_size_change   = super_1_rdev_size_change,
1469 	},
1470 };
1471 
1472 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1473 {
1474 	mdk_rdev_t *rdev, *rdev2;
1475 
1476 	rcu_read_lock();
1477 	rdev_for_each_rcu(rdev, mddev1)
1478 		rdev_for_each_rcu(rdev2, mddev2)
1479 			if (rdev->bdev->bd_contains ==
1480 			    rdev2->bdev->bd_contains) {
1481 				rcu_read_unlock();
1482 				return 1;
1483 			}
1484 	rcu_read_unlock();
1485 	return 0;
1486 }
1487 
1488 static LIST_HEAD(pending_raid_disks);
1489 
1490 static void md_integrity_check(mdk_rdev_t *rdev, mddev_t *mddev)
1491 {
1492 	struct mdk_personality *pers = mddev->pers;
1493 	struct gendisk *disk = mddev->gendisk;
1494 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1495 	struct blk_integrity *bi_mddev = blk_get_integrity(disk);
1496 
1497 	/* Data integrity passthrough not supported on RAID 4, 5 and 6 */
1498 	if (pers && pers->level >= 4 && pers->level <= 6)
1499 		return;
1500 
1501 	/* If rdev is integrity capable, register profile for mddev */
1502 	if (!bi_mddev && bi_rdev) {
1503 		if (blk_integrity_register(disk, bi_rdev))
1504 			printk(KERN_ERR "%s: %s Could not register integrity!\n",
1505 			       __func__, disk->disk_name);
1506 		else
1507 			printk(KERN_NOTICE "Enabling data integrity on %s\n",
1508 			       disk->disk_name);
1509 		return;
1510 	}
1511 
1512 	/* Check that mddev and rdev have matching profiles */
1513 	if (blk_integrity_compare(disk, rdev->bdev->bd_disk) < 0) {
1514 		printk(KERN_ERR "%s: %s/%s integrity mismatch!\n", __func__,
1515 		       disk->disk_name, rdev->bdev->bd_disk->disk_name);
1516 		printk(KERN_NOTICE "Disabling data integrity on %s\n",
1517 		       disk->disk_name);
1518 		blk_integrity_unregister(disk);
1519 	}
1520 }
1521 
1522 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1523 {
1524 	char b[BDEVNAME_SIZE];
1525 	struct kobject *ko;
1526 	char *s;
1527 	int err;
1528 
1529 	if (rdev->mddev) {
1530 		MD_BUG();
1531 		return -EINVAL;
1532 	}
1533 
1534 	/* prevent duplicates */
1535 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1536 		return -EEXIST;
1537 
1538 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
1539 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
1540 			rdev->sectors < mddev->dev_sectors)) {
1541 		if (mddev->pers) {
1542 			/* Cannot change size, so fail
1543 			 * If mddev->level <= 0, then we don't care
1544 			 * about aligning sizes (e.g. linear)
1545 			 */
1546 			if (mddev->level > 0)
1547 				return -ENOSPC;
1548 		} else
1549 			mddev->dev_sectors = rdev->sectors;
1550 	}
1551 
1552 	/* Verify rdev->desc_nr is unique.
1553 	 * If it is -1, assign a free number, else
1554 	 * check number is not in use
1555 	 */
1556 	if (rdev->desc_nr < 0) {
1557 		int choice = 0;
1558 		if (mddev->pers) choice = mddev->raid_disks;
1559 		while (find_rdev_nr(mddev, choice))
1560 			choice++;
1561 		rdev->desc_nr = choice;
1562 	} else {
1563 		if (find_rdev_nr(mddev, rdev->desc_nr))
1564 			return -EBUSY;
1565 	}
1566 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1567 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1568 		       mdname(mddev), mddev->max_disks);
1569 		return -EBUSY;
1570 	}
1571 	bdevname(rdev->bdev,b);
1572 	while ( (s=strchr(b, '/')) != NULL)
1573 		*s = '!';
1574 
1575 	rdev->mddev = mddev;
1576 	printk(KERN_INFO "md: bind<%s>\n", b);
1577 
1578 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1579 		goto fail;
1580 
1581 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1582 	if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
1583 		kobject_del(&rdev->kobj);
1584 		goto fail;
1585 	}
1586 	rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, "state");
1587 
1588 	list_add_rcu(&rdev->same_set, &mddev->disks);
1589 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1590 
1591 	/* May as well allow recovery to be retried once */
1592 	mddev->recovery_disabled = 0;
1593 
1594 	md_integrity_check(rdev, mddev);
1595 	return 0;
1596 
1597  fail:
1598 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1599 	       b, mdname(mddev));
1600 	return err;
1601 }
1602 
1603 static void md_delayed_delete(struct work_struct *ws)
1604 {
1605 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1606 	kobject_del(&rdev->kobj);
1607 	kobject_put(&rdev->kobj);
1608 }
1609 
1610 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1611 {
1612 	char b[BDEVNAME_SIZE];
1613 	if (!rdev->mddev) {
1614 		MD_BUG();
1615 		return;
1616 	}
1617 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1618 	list_del_rcu(&rdev->same_set);
1619 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1620 	rdev->mddev = NULL;
1621 	sysfs_remove_link(&rdev->kobj, "block");
1622 	sysfs_put(rdev->sysfs_state);
1623 	rdev->sysfs_state = NULL;
1624 	/* We need to delay this, otherwise we can deadlock when
1625 	 * writing to 'remove' to "dev/state".  We also need
1626 	 * to delay it due to rcu usage.
1627 	 */
1628 	synchronize_rcu();
1629 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1630 	kobject_get(&rdev->kobj);
1631 	schedule_work(&rdev->del_work);
1632 }
1633 
1634 /*
1635  * prevent the device from being mounted, repartitioned or
1636  * otherwise reused by a RAID array (or any other kernel
1637  * subsystem), by bd_claiming the device.
1638  */
1639 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1640 {
1641 	int err = 0;
1642 	struct block_device *bdev;
1643 	char b[BDEVNAME_SIZE];
1644 
1645 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1646 	if (IS_ERR(bdev)) {
1647 		printk(KERN_ERR "md: could not open %s.\n",
1648 			__bdevname(dev, b));
1649 		return PTR_ERR(bdev);
1650 	}
1651 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1652 	if (err) {
1653 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1654 			bdevname(bdev, b));
1655 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1656 		return err;
1657 	}
1658 	if (!shared)
1659 		set_bit(AllReserved, &rdev->flags);
1660 	rdev->bdev = bdev;
1661 	return err;
1662 }
1663 
1664 static void unlock_rdev(mdk_rdev_t *rdev)
1665 {
1666 	struct block_device *bdev = rdev->bdev;
1667 	rdev->bdev = NULL;
1668 	if (!bdev)
1669 		MD_BUG();
1670 	bd_release(bdev);
1671 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1672 }
1673 
1674 void md_autodetect_dev(dev_t dev);
1675 
1676 static void export_rdev(mdk_rdev_t * rdev)
1677 {
1678 	char b[BDEVNAME_SIZE];
1679 	printk(KERN_INFO "md: export_rdev(%s)\n",
1680 		bdevname(rdev->bdev,b));
1681 	if (rdev->mddev)
1682 		MD_BUG();
1683 	free_disk_sb(rdev);
1684 #ifndef MODULE
1685 	if (test_bit(AutoDetected, &rdev->flags))
1686 		md_autodetect_dev(rdev->bdev->bd_dev);
1687 #endif
1688 	unlock_rdev(rdev);
1689 	kobject_put(&rdev->kobj);
1690 }
1691 
1692 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1693 {
1694 	unbind_rdev_from_array(rdev);
1695 	export_rdev(rdev);
1696 }
1697 
1698 static void export_array(mddev_t *mddev)
1699 {
1700 	mdk_rdev_t *rdev, *tmp;
1701 
1702 	rdev_for_each(rdev, tmp, mddev) {
1703 		if (!rdev->mddev) {
1704 			MD_BUG();
1705 			continue;
1706 		}
1707 		kick_rdev_from_array(rdev);
1708 	}
1709 	if (!list_empty(&mddev->disks))
1710 		MD_BUG();
1711 	mddev->raid_disks = 0;
1712 	mddev->major_version = 0;
1713 }
1714 
1715 static void print_desc(mdp_disk_t *desc)
1716 {
1717 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1718 		desc->major,desc->minor,desc->raid_disk,desc->state);
1719 }
1720 
1721 static void print_sb_90(mdp_super_t *sb)
1722 {
1723 	int i;
1724 
1725 	printk(KERN_INFO
1726 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1727 		sb->major_version, sb->minor_version, sb->patch_version,
1728 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1729 		sb->ctime);
1730 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1731 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1732 		sb->md_minor, sb->layout, sb->chunk_size);
1733 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1734 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1735 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1736 		sb->failed_disks, sb->spare_disks,
1737 		sb->sb_csum, (unsigned long)sb->events_lo);
1738 
1739 	printk(KERN_INFO);
1740 	for (i = 0; i < MD_SB_DISKS; i++) {
1741 		mdp_disk_t *desc;
1742 
1743 		desc = sb->disks + i;
1744 		if (desc->number || desc->major || desc->minor ||
1745 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1746 			printk("     D %2d: ", i);
1747 			print_desc(desc);
1748 		}
1749 	}
1750 	printk(KERN_INFO "md:     THIS: ");
1751 	print_desc(&sb->this_disk);
1752 }
1753 
1754 static void print_sb_1(struct mdp_superblock_1 *sb)
1755 {
1756 	__u8 *uuid;
1757 
1758 	uuid = sb->set_uuid;
1759 	printk(KERN_INFO
1760 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%02x%02x%02x%02x"
1761 	       ":%02x%02x:%02x%02x:%02x%02x:%02x%02x%02x%02x%02x%02x>\n"
1762 	       "md:    Name: \"%s\" CT:%llu\n",
1763 		le32_to_cpu(sb->major_version),
1764 		le32_to_cpu(sb->feature_map),
1765 		uuid[0], uuid[1], uuid[2], uuid[3],
1766 		uuid[4], uuid[5], uuid[6], uuid[7],
1767 		uuid[8], uuid[9], uuid[10], uuid[11],
1768 		uuid[12], uuid[13], uuid[14], uuid[15],
1769 		sb->set_name,
1770 		(unsigned long long)le64_to_cpu(sb->ctime)
1771 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
1772 
1773 	uuid = sb->device_uuid;
1774 	printk(KERN_INFO
1775 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
1776 			" RO:%llu\n"
1777 	       "md:     Dev:%08x UUID: %02x%02x%02x%02x:%02x%02x:%02x%02x:%02x%02x"
1778 	                ":%02x%02x%02x%02x%02x%02x\n"
1779 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
1780 	       "md:         (MaxDev:%u) \n",
1781 		le32_to_cpu(sb->level),
1782 		(unsigned long long)le64_to_cpu(sb->size),
1783 		le32_to_cpu(sb->raid_disks),
1784 		le32_to_cpu(sb->layout),
1785 		le32_to_cpu(sb->chunksize),
1786 		(unsigned long long)le64_to_cpu(sb->data_offset),
1787 		(unsigned long long)le64_to_cpu(sb->data_size),
1788 		(unsigned long long)le64_to_cpu(sb->super_offset),
1789 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
1790 		le32_to_cpu(sb->dev_number),
1791 		uuid[0], uuid[1], uuid[2], uuid[3],
1792 		uuid[4], uuid[5], uuid[6], uuid[7],
1793 		uuid[8], uuid[9], uuid[10], uuid[11],
1794 		uuid[12], uuid[13], uuid[14], uuid[15],
1795 		sb->devflags,
1796 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
1797 		(unsigned long long)le64_to_cpu(sb->events),
1798 		(unsigned long long)le64_to_cpu(sb->resync_offset),
1799 		le32_to_cpu(sb->sb_csum),
1800 		le32_to_cpu(sb->max_dev)
1801 		);
1802 }
1803 
1804 static void print_rdev(mdk_rdev_t *rdev, int major_version)
1805 {
1806 	char b[BDEVNAME_SIZE];
1807 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
1808 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
1809 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1810 	        rdev->desc_nr);
1811 	if (rdev->sb_loaded) {
1812 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
1813 		switch (major_version) {
1814 		case 0:
1815 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
1816 			break;
1817 		case 1:
1818 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
1819 			break;
1820 		}
1821 	} else
1822 		printk(KERN_INFO "md: no rdev superblock!\n");
1823 }
1824 
1825 static void md_print_devices(void)
1826 {
1827 	struct list_head *tmp;
1828 	mdk_rdev_t *rdev;
1829 	mddev_t *mddev;
1830 	char b[BDEVNAME_SIZE];
1831 
1832 	printk("\n");
1833 	printk("md:	**********************************\n");
1834 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1835 	printk("md:	**********************************\n");
1836 	for_each_mddev(mddev, tmp) {
1837 
1838 		if (mddev->bitmap)
1839 			bitmap_print_sb(mddev->bitmap);
1840 		else
1841 			printk("%s: ", mdname(mddev));
1842 		list_for_each_entry(rdev, &mddev->disks, same_set)
1843 			printk("<%s>", bdevname(rdev->bdev,b));
1844 		printk("\n");
1845 
1846 		list_for_each_entry(rdev, &mddev->disks, same_set)
1847 			print_rdev(rdev, mddev->major_version);
1848 	}
1849 	printk("md:	**********************************\n");
1850 	printk("\n");
1851 }
1852 
1853 
1854 static void sync_sbs(mddev_t * mddev, int nospares)
1855 {
1856 	/* Update each superblock (in-memory image), but
1857 	 * if we are allowed to, skip spares which already
1858 	 * have the right event counter, or have one earlier
1859 	 * (which would mean they aren't being marked as dirty
1860 	 * with the rest of the array)
1861 	 */
1862 	mdk_rdev_t *rdev;
1863 
1864 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1865 		if (rdev->sb_events == mddev->events ||
1866 		    (nospares &&
1867 		     rdev->raid_disk < 0 &&
1868 		     (rdev->sb_events&1)==0 &&
1869 		     rdev->sb_events+1 == mddev->events)) {
1870 			/* Don't update this superblock */
1871 			rdev->sb_loaded = 2;
1872 		} else {
1873 			super_types[mddev->major_version].
1874 				sync_super(mddev, rdev);
1875 			rdev->sb_loaded = 1;
1876 		}
1877 	}
1878 }
1879 
1880 static void md_update_sb(mddev_t * mddev, int force_change)
1881 {
1882 	mdk_rdev_t *rdev;
1883 	int sync_req;
1884 	int nospares = 0;
1885 
1886 	mddev->utime = get_seconds();
1887 	if (mddev->external)
1888 		return;
1889 repeat:
1890 	spin_lock_irq(&mddev->write_lock);
1891 
1892 	set_bit(MD_CHANGE_PENDING, &mddev->flags);
1893 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
1894 		force_change = 1;
1895 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
1896 		/* just a clean<-> dirty transition, possibly leave spares alone,
1897 		 * though if events isn't the right even/odd, we will have to do
1898 		 * spares after all
1899 		 */
1900 		nospares = 1;
1901 	if (force_change)
1902 		nospares = 0;
1903 	if (mddev->degraded)
1904 		/* If the array is degraded, then skipping spares is both
1905 		 * dangerous and fairly pointless.
1906 		 * Dangerous because a device that was removed from the array
1907 		 * might have a event_count that still looks up-to-date,
1908 		 * so it can be re-added without a resync.
1909 		 * Pointless because if there are any spares to skip,
1910 		 * then a recovery will happen and soon that array won't
1911 		 * be degraded any more and the spare can go back to sleep then.
1912 		 */
1913 		nospares = 0;
1914 
1915 	sync_req = mddev->in_sync;
1916 
1917 	/* If this is just a dirty<->clean transition, and the array is clean
1918 	 * and 'events' is odd, we can roll back to the previous clean state */
1919 	if (nospares
1920 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
1921 	    && (mddev->events & 1)
1922 	    && mddev->events != 1)
1923 		mddev->events--;
1924 	else {
1925 		/* otherwise we have to go forward and ... */
1926 		mddev->events ++;
1927 		if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
1928 			/* .. if the array isn't clean, insist on an odd 'events' */
1929 			if ((mddev->events&1)==0) {
1930 				mddev->events++;
1931 				nospares = 0;
1932 			}
1933 		} else {
1934 			/* otherwise insist on an even 'events' (for clean states) */
1935 			if ((mddev->events&1)) {
1936 				mddev->events++;
1937 				nospares = 0;
1938 			}
1939 		}
1940 	}
1941 
1942 	if (!mddev->events) {
1943 		/*
1944 		 * oops, this 64-bit counter should never wrap.
1945 		 * Either we are in around ~1 trillion A.C., assuming
1946 		 * 1 reboot per second, or we have a bug:
1947 		 */
1948 		MD_BUG();
1949 		mddev->events --;
1950 	}
1951 
1952 	/*
1953 	 * do not write anything to disk if using
1954 	 * nonpersistent superblocks
1955 	 */
1956 	if (!mddev->persistent) {
1957 		if (!mddev->external)
1958 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
1959 
1960 		spin_unlock_irq(&mddev->write_lock);
1961 		wake_up(&mddev->sb_wait);
1962 		return;
1963 	}
1964 	sync_sbs(mddev, nospares);
1965 	spin_unlock_irq(&mddev->write_lock);
1966 
1967 	dprintk(KERN_INFO
1968 		"md: updating %s RAID superblock on device (in sync %d)\n",
1969 		mdname(mddev),mddev->in_sync);
1970 
1971 	bitmap_update_sb(mddev->bitmap);
1972 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1973 		char b[BDEVNAME_SIZE];
1974 		dprintk(KERN_INFO "md: ");
1975 		if (rdev->sb_loaded != 1)
1976 			continue; /* no noise on spare devices */
1977 		if (test_bit(Faulty, &rdev->flags))
1978 			dprintk("(skipping faulty ");
1979 
1980 		dprintk("%s ", bdevname(rdev->bdev,b));
1981 		if (!test_bit(Faulty, &rdev->flags)) {
1982 			md_super_write(mddev,rdev,
1983 				       rdev->sb_start, rdev->sb_size,
1984 				       rdev->sb_page);
1985 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1986 				bdevname(rdev->bdev,b),
1987 				(unsigned long long)rdev->sb_start);
1988 			rdev->sb_events = mddev->events;
1989 
1990 		} else
1991 			dprintk(")\n");
1992 		if (mddev->level == LEVEL_MULTIPATH)
1993 			/* only need to write one superblock... */
1994 			break;
1995 	}
1996 	md_super_wait(mddev);
1997 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
1998 
1999 	spin_lock_irq(&mddev->write_lock);
2000 	if (mddev->in_sync != sync_req ||
2001 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2002 		/* have to write it out again */
2003 		spin_unlock_irq(&mddev->write_lock);
2004 		goto repeat;
2005 	}
2006 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2007 	spin_unlock_irq(&mddev->write_lock);
2008 	wake_up(&mddev->sb_wait);
2009 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2010 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2011 
2012 }
2013 
2014 /* words written to sysfs files may, or may not, be \n terminated.
2015  * We want to accept with case. For this we use cmd_match.
2016  */
2017 static int cmd_match(const char *cmd, const char *str)
2018 {
2019 	/* See if cmd, written into a sysfs file, matches
2020 	 * str.  They must either be the same, or cmd can
2021 	 * have a trailing newline
2022 	 */
2023 	while (*cmd && *str && *cmd == *str) {
2024 		cmd++;
2025 		str++;
2026 	}
2027 	if (*cmd == '\n')
2028 		cmd++;
2029 	if (*str || *cmd)
2030 		return 0;
2031 	return 1;
2032 }
2033 
2034 struct rdev_sysfs_entry {
2035 	struct attribute attr;
2036 	ssize_t (*show)(mdk_rdev_t *, char *);
2037 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2038 };
2039 
2040 static ssize_t
2041 state_show(mdk_rdev_t *rdev, char *page)
2042 {
2043 	char *sep = "";
2044 	size_t len = 0;
2045 
2046 	if (test_bit(Faulty, &rdev->flags)) {
2047 		len+= sprintf(page+len, "%sfaulty",sep);
2048 		sep = ",";
2049 	}
2050 	if (test_bit(In_sync, &rdev->flags)) {
2051 		len += sprintf(page+len, "%sin_sync",sep);
2052 		sep = ",";
2053 	}
2054 	if (test_bit(WriteMostly, &rdev->flags)) {
2055 		len += sprintf(page+len, "%swrite_mostly",sep);
2056 		sep = ",";
2057 	}
2058 	if (test_bit(Blocked, &rdev->flags)) {
2059 		len += sprintf(page+len, "%sblocked", sep);
2060 		sep = ",";
2061 	}
2062 	if (!test_bit(Faulty, &rdev->flags) &&
2063 	    !test_bit(In_sync, &rdev->flags)) {
2064 		len += sprintf(page+len, "%sspare", sep);
2065 		sep = ",";
2066 	}
2067 	return len+sprintf(page+len, "\n");
2068 }
2069 
2070 static ssize_t
2071 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2072 {
2073 	/* can write
2074 	 *  faulty  - simulates and error
2075 	 *  remove  - disconnects the device
2076 	 *  writemostly - sets write_mostly
2077 	 *  -writemostly - clears write_mostly
2078 	 *  blocked - sets the Blocked flag
2079 	 *  -blocked - clears the Blocked flag
2080 	 *  insync - sets Insync providing device isn't active
2081 	 */
2082 	int err = -EINVAL;
2083 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2084 		md_error(rdev->mddev, rdev);
2085 		err = 0;
2086 	} else if (cmd_match(buf, "remove")) {
2087 		if (rdev->raid_disk >= 0)
2088 			err = -EBUSY;
2089 		else {
2090 			mddev_t *mddev = rdev->mddev;
2091 			kick_rdev_from_array(rdev);
2092 			if (mddev->pers)
2093 				md_update_sb(mddev, 1);
2094 			md_new_event(mddev);
2095 			err = 0;
2096 		}
2097 	} else if (cmd_match(buf, "writemostly")) {
2098 		set_bit(WriteMostly, &rdev->flags);
2099 		err = 0;
2100 	} else if (cmd_match(buf, "-writemostly")) {
2101 		clear_bit(WriteMostly, &rdev->flags);
2102 		err = 0;
2103 	} else if (cmd_match(buf, "blocked")) {
2104 		set_bit(Blocked, &rdev->flags);
2105 		err = 0;
2106 	} else if (cmd_match(buf, "-blocked")) {
2107 		clear_bit(Blocked, &rdev->flags);
2108 		wake_up(&rdev->blocked_wait);
2109 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2110 		md_wakeup_thread(rdev->mddev->thread);
2111 
2112 		err = 0;
2113 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2114 		set_bit(In_sync, &rdev->flags);
2115 		err = 0;
2116 	}
2117 	if (!err && rdev->sysfs_state)
2118 		sysfs_notify_dirent(rdev->sysfs_state);
2119 	return err ? err : len;
2120 }
2121 static struct rdev_sysfs_entry rdev_state =
2122 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2123 
2124 static ssize_t
2125 errors_show(mdk_rdev_t *rdev, char *page)
2126 {
2127 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2128 }
2129 
2130 static ssize_t
2131 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2132 {
2133 	char *e;
2134 	unsigned long n = simple_strtoul(buf, &e, 10);
2135 	if (*buf && (*e == 0 || *e == '\n')) {
2136 		atomic_set(&rdev->corrected_errors, n);
2137 		return len;
2138 	}
2139 	return -EINVAL;
2140 }
2141 static struct rdev_sysfs_entry rdev_errors =
2142 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2143 
2144 static ssize_t
2145 slot_show(mdk_rdev_t *rdev, char *page)
2146 {
2147 	if (rdev->raid_disk < 0)
2148 		return sprintf(page, "none\n");
2149 	else
2150 		return sprintf(page, "%d\n", rdev->raid_disk);
2151 }
2152 
2153 static ssize_t
2154 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2155 {
2156 	char *e;
2157 	int err;
2158 	char nm[20];
2159 	int slot = simple_strtoul(buf, &e, 10);
2160 	if (strncmp(buf, "none", 4)==0)
2161 		slot = -1;
2162 	else if (e==buf || (*e && *e!= '\n'))
2163 		return -EINVAL;
2164 	if (rdev->mddev->pers && slot == -1) {
2165 		/* Setting 'slot' on an active array requires also
2166 		 * updating the 'rd%d' link, and communicating
2167 		 * with the personality with ->hot_*_disk.
2168 		 * For now we only support removing
2169 		 * failed/spare devices.  This normally happens automatically,
2170 		 * but not when the metadata is externally managed.
2171 		 */
2172 		if (rdev->raid_disk == -1)
2173 			return -EEXIST;
2174 		/* personality does all needed checks */
2175 		if (rdev->mddev->pers->hot_add_disk == NULL)
2176 			return -EINVAL;
2177 		err = rdev->mddev->pers->
2178 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2179 		if (err)
2180 			return err;
2181 		sprintf(nm, "rd%d", rdev->raid_disk);
2182 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2183 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2184 		md_wakeup_thread(rdev->mddev->thread);
2185 	} else if (rdev->mddev->pers) {
2186 		mdk_rdev_t *rdev2;
2187 		/* Activating a spare .. or possibly reactivating
2188 		 * if we ever get bitmaps working here.
2189 		 */
2190 
2191 		if (rdev->raid_disk != -1)
2192 			return -EBUSY;
2193 
2194 		if (rdev->mddev->pers->hot_add_disk == NULL)
2195 			return -EINVAL;
2196 
2197 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2198 			if (rdev2->raid_disk == slot)
2199 				return -EEXIST;
2200 
2201 		rdev->raid_disk = slot;
2202 		if (test_bit(In_sync, &rdev->flags))
2203 			rdev->saved_raid_disk = slot;
2204 		else
2205 			rdev->saved_raid_disk = -1;
2206 		err = rdev->mddev->pers->
2207 			hot_add_disk(rdev->mddev, rdev);
2208 		if (err) {
2209 			rdev->raid_disk = -1;
2210 			return err;
2211 		} else
2212 			sysfs_notify_dirent(rdev->sysfs_state);
2213 		sprintf(nm, "rd%d", rdev->raid_disk);
2214 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2215 			printk(KERN_WARNING
2216 			       "md: cannot register "
2217 			       "%s for %s\n",
2218 			       nm, mdname(rdev->mddev));
2219 
2220 		/* don't wakeup anyone, leave that to userspace. */
2221 	} else {
2222 		if (slot >= rdev->mddev->raid_disks)
2223 			return -ENOSPC;
2224 		rdev->raid_disk = slot;
2225 		/* assume it is working */
2226 		clear_bit(Faulty, &rdev->flags);
2227 		clear_bit(WriteMostly, &rdev->flags);
2228 		set_bit(In_sync, &rdev->flags);
2229 		sysfs_notify_dirent(rdev->sysfs_state);
2230 	}
2231 	return len;
2232 }
2233 
2234 
2235 static struct rdev_sysfs_entry rdev_slot =
2236 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2237 
2238 static ssize_t
2239 offset_show(mdk_rdev_t *rdev, char *page)
2240 {
2241 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2242 }
2243 
2244 static ssize_t
2245 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2246 {
2247 	char *e;
2248 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2249 	if (e==buf || (*e && *e != '\n'))
2250 		return -EINVAL;
2251 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2252 		return -EBUSY;
2253 	if (rdev->sectors && rdev->mddev->external)
2254 		/* Must set offset before size, so overlap checks
2255 		 * can be sane */
2256 		return -EBUSY;
2257 	rdev->data_offset = offset;
2258 	return len;
2259 }
2260 
2261 static struct rdev_sysfs_entry rdev_offset =
2262 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2263 
2264 static ssize_t
2265 rdev_size_show(mdk_rdev_t *rdev, char *page)
2266 {
2267 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2268 }
2269 
2270 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2271 {
2272 	/* check if two start/length pairs overlap */
2273 	if (s1+l1 <= s2)
2274 		return 0;
2275 	if (s2+l2 <= s1)
2276 		return 0;
2277 	return 1;
2278 }
2279 
2280 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2281 {
2282 	unsigned long long blocks;
2283 	sector_t new;
2284 
2285 	if (strict_strtoull(buf, 10, &blocks) < 0)
2286 		return -EINVAL;
2287 
2288 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2289 		return -EINVAL; /* sector conversion overflow */
2290 
2291 	new = blocks * 2;
2292 	if (new != blocks * 2)
2293 		return -EINVAL; /* unsigned long long to sector_t overflow */
2294 
2295 	*sectors = new;
2296 	return 0;
2297 }
2298 
2299 static ssize_t
2300 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2301 {
2302 	mddev_t *my_mddev = rdev->mddev;
2303 	sector_t oldsectors = rdev->sectors;
2304 	sector_t sectors;
2305 
2306 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2307 		return -EINVAL;
2308 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2309 		if (my_mddev->persistent) {
2310 			sectors = super_types[my_mddev->major_version].
2311 				rdev_size_change(rdev, sectors);
2312 			if (!sectors)
2313 				return -EBUSY;
2314 		} else if (!sectors)
2315 			sectors = (rdev->bdev->bd_inode->i_size >> 9) -
2316 				rdev->data_offset;
2317 	}
2318 	if (sectors < my_mddev->dev_sectors)
2319 		return -EINVAL; /* component must fit device */
2320 
2321 	rdev->sectors = sectors;
2322 	if (sectors > oldsectors && my_mddev->external) {
2323 		/* need to check that all other rdevs with the same ->bdev
2324 		 * do not overlap.  We need to unlock the mddev to avoid
2325 		 * a deadlock.  We have already changed rdev->sectors, and if
2326 		 * we have to change it back, we will have the lock again.
2327 		 */
2328 		mddev_t *mddev;
2329 		int overlap = 0;
2330 		struct list_head *tmp;
2331 
2332 		mddev_unlock(my_mddev);
2333 		for_each_mddev(mddev, tmp) {
2334 			mdk_rdev_t *rdev2;
2335 
2336 			mddev_lock(mddev);
2337 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2338 				if (test_bit(AllReserved, &rdev2->flags) ||
2339 				    (rdev->bdev == rdev2->bdev &&
2340 				     rdev != rdev2 &&
2341 				     overlaps(rdev->data_offset, rdev->sectors,
2342 					      rdev2->data_offset,
2343 					      rdev2->sectors))) {
2344 					overlap = 1;
2345 					break;
2346 				}
2347 			mddev_unlock(mddev);
2348 			if (overlap) {
2349 				mddev_put(mddev);
2350 				break;
2351 			}
2352 		}
2353 		mddev_lock(my_mddev);
2354 		if (overlap) {
2355 			/* Someone else could have slipped in a size
2356 			 * change here, but doing so is just silly.
2357 			 * We put oldsectors back because we *know* it is
2358 			 * safe, and trust userspace not to race with
2359 			 * itself
2360 			 */
2361 			rdev->sectors = oldsectors;
2362 			return -EBUSY;
2363 		}
2364 	}
2365 	return len;
2366 }
2367 
2368 static struct rdev_sysfs_entry rdev_size =
2369 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2370 
2371 static struct attribute *rdev_default_attrs[] = {
2372 	&rdev_state.attr,
2373 	&rdev_errors.attr,
2374 	&rdev_slot.attr,
2375 	&rdev_offset.attr,
2376 	&rdev_size.attr,
2377 	NULL,
2378 };
2379 static ssize_t
2380 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2381 {
2382 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2383 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2384 	mddev_t *mddev = rdev->mddev;
2385 	ssize_t rv;
2386 
2387 	if (!entry->show)
2388 		return -EIO;
2389 
2390 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2391 	if (!rv) {
2392 		if (rdev->mddev == NULL)
2393 			rv = -EBUSY;
2394 		else
2395 			rv = entry->show(rdev, page);
2396 		mddev_unlock(mddev);
2397 	}
2398 	return rv;
2399 }
2400 
2401 static ssize_t
2402 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2403 	      const char *page, size_t length)
2404 {
2405 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2406 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2407 	ssize_t rv;
2408 	mddev_t *mddev = rdev->mddev;
2409 
2410 	if (!entry->store)
2411 		return -EIO;
2412 	if (!capable(CAP_SYS_ADMIN))
2413 		return -EACCES;
2414 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2415 	if (!rv) {
2416 		if (rdev->mddev == NULL)
2417 			rv = -EBUSY;
2418 		else
2419 			rv = entry->store(rdev, page, length);
2420 		mddev_unlock(mddev);
2421 	}
2422 	return rv;
2423 }
2424 
2425 static void rdev_free(struct kobject *ko)
2426 {
2427 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2428 	kfree(rdev);
2429 }
2430 static struct sysfs_ops rdev_sysfs_ops = {
2431 	.show		= rdev_attr_show,
2432 	.store		= rdev_attr_store,
2433 };
2434 static struct kobj_type rdev_ktype = {
2435 	.release	= rdev_free,
2436 	.sysfs_ops	= &rdev_sysfs_ops,
2437 	.default_attrs	= rdev_default_attrs,
2438 };
2439 
2440 /*
2441  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2442  *
2443  * mark the device faulty if:
2444  *
2445  *   - the device is nonexistent (zero size)
2446  *   - the device has no valid superblock
2447  *
2448  * a faulty rdev _never_ has rdev->sb set.
2449  */
2450 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2451 {
2452 	char b[BDEVNAME_SIZE];
2453 	int err;
2454 	mdk_rdev_t *rdev;
2455 	sector_t size;
2456 
2457 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2458 	if (!rdev) {
2459 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2460 		return ERR_PTR(-ENOMEM);
2461 	}
2462 
2463 	if ((err = alloc_disk_sb(rdev)))
2464 		goto abort_free;
2465 
2466 	err = lock_rdev(rdev, newdev, super_format == -2);
2467 	if (err)
2468 		goto abort_free;
2469 
2470 	kobject_init(&rdev->kobj, &rdev_ktype);
2471 
2472 	rdev->desc_nr = -1;
2473 	rdev->saved_raid_disk = -1;
2474 	rdev->raid_disk = -1;
2475 	rdev->flags = 0;
2476 	rdev->data_offset = 0;
2477 	rdev->sb_events = 0;
2478 	atomic_set(&rdev->nr_pending, 0);
2479 	atomic_set(&rdev->read_errors, 0);
2480 	atomic_set(&rdev->corrected_errors, 0);
2481 
2482 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2483 	if (!size) {
2484 		printk(KERN_WARNING
2485 			"md: %s has zero or unknown size, marking faulty!\n",
2486 			bdevname(rdev->bdev,b));
2487 		err = -EINVAL;
2488 		goto abort_free;
2489 	}
2490 
2491 	if (super_format >= 0) {
2492 		err = super_types[super_format].
2493 			load_super(rdev, NULL, super_minor);
2494 		if (err == -EINVAL) {
2495 			printk(KERN_WARNING
2496 				"md: %s does not have a valid v%d.%d "
2497 			       "superblock, not importing!\n",
2498 				bdevname(rdev->bdev,b),
2499 			       super_format, super_minor);
2500 			goto abort_free;
2501 		}
2502 		if (err < 0) {
2503 			printk(KERN_WARNING
2504 				"md: could not read %s's sb, not importing!\n",
2505 				bdevname(rdev->bdev,b));
2506 			goto abort_free;
2507 		}
2508 	}
2509 
2510 	INIT_LIST_HEAD(&rdev->same_set);
2511 	init_waitqueue_head(&rdev->blocked_wait);
2512 
2513 	return rdev;
2514 
2515 abort_free:
2516 	if (rdev->sb_page) {
2517 		if (rdev->bdev)
2518 			unlock_rdev(rdev);
2519 		free_disk_sb(rdev);
2520 	}
2521 	kfree(rdev);
2522 	return ERR_PTR(err);
2523 }
2524 
2525 /*
2526  * Check a full RAID array for plausibility
2527  */
2528 
2529 
2530 static void analyze_sbs(mddev_t * mddev)
2531 {
2532 	int i;
2533 	mdk_rdev_t *rdev, *freshest, *tmp;
2534 	char b[BDEVNAME_SIZE];
2535 
2536 	freshest = NULL;
2537 	rdev_for_each(rdev, tmp, mddev)
2538 		switch (super_types[mddev->major_version].
2539 			load_super(rdev, freshest, mddev->minor_version)) {
2540 		case 1:
2541 			freshest = rdev;
2542 			break;
2543 		case 0:
2544 			break;
2545 		default:
2546 			printk( KERN_ERR \
2547 				"md: fatal superblock inconsistency in %s"
2548 				" -- removing from array\n",
2549 				bdevname(rdev->bdev,b));
2550 			kick_rdev_from_array(rdev);
2551 		}
2552 
2553 
2554 	super_types[mddev->major_version].
2555 		validate_super(mddev, freshest);
2556 
2557 	i = 0;
2558 	rdev_for_each(rdev, tmp, mddev) {
2559 		if (rdev->desc_nr >= mddev->max_disks ||
2560 		    i > mddev->max_disks) {
2561 			printk(KERN_WARNING
2562 			       "md: %s: %s: only %d devices permitted\n",
2563 			       mdname(mddev), bdevname(rdev->bdev, b),
2564 			       mddev->max_disks);
2565 			kick_rdev_from_array(rdev);
2566 			continue;
2567 		}
2568 		if (rdev != freshest)
2569 			if (super_types[mddev->major_version].
2570 			    validate_super(mddev, rdev)) {
2571 				printk(KERN_WARNING "md: kicking non-fresh %s"
2572 					" from array!\n",
2573 					bdevname(rdev->bdev,b));
2574 				kick_rdev_from_array(rdev);
2575 				continue;
2576 			}
2577 		if (mddev->level == LEVEL_MULTIPATH) {
2578 			rdev->desc_nr = i++;
2579 			rdev->raid_disk = rdev->desc_nr;
2580 			set_bit(In_sync, &rdev->flags);
2581 		} else if (rdev->raid_disk >= mddev->raid_disks) {
2582 			rdev->raid_disk = -1;
2583 			clear_bit(In_sync, &rdev->flags);
2584 		}
2585 	}
2586 }
2587 
2588 static void md_safemode_timeout(unsigned long data);
2589 
2590 static ssize_t
2591 safe_delay_show(mddev_t *mddev, char *page)
2592 {
2593 	int msec = (mddev->safemode_delay*1000)/HZ;
2594 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2595 }
2596 static ssize_t
2597 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2598 {
2599 	int scale=1;
2600 	int dot=0;
2601 	int i;
2602 	unsigned long msec;
2603 	char buf[30];
2604 
2605 	/* remove a period, and count digits after it */
2606 	if (len >= sizeof(buf))
2607 		return -EINVAL;
2608 	strlcpy(buf, cbuf, sizeof(buf));
2609 	for (i=0; i<len; i++) {
2610 		if (dot) {
2611 			if (isdigit(buf[i])) {
2612 				buf[i-1] = buf[i];
2613 				scale *= 10;
2614 			}
2615 			buf[i] = 0;
2616 		} else if (buf[i] == '.') {
2617 			dot=1;
2618 			buf[i] = 0;
2619 		}
2620 	}
2621 	if (strict_strtoul(buf, 10, &msec) < 0)
2622 		return -EINVAL;
2623 	msec = (msec * 1000) / scale;
2624 	if (msec == 0)
2625 		mddev->safemode_delay = 0;
2626 	else {
2627 		unsigned long old_delay = mddev->safemode_delay;
2628 		mddev->safemode_delay = (msec*HZ)/1000;
2629 		if (mddev->safemode_delay == 0)
2630 			mddev->safemode_delay = 1;
2631 		if (mddev->safemode_delay < old_delay)
2632 			md_safemode_timeout((unsigned long)mddev);
2633 	}
2634 	return len;
2635 }
2636 static struct md_sysfs_entry md_safe_delay =
2637 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2638 
2639 static ssize_t
2640 level_show(mddev_t *mddev, char *page)
2641 {
2642 	struct mdk_personality *p = mddev->pers;
2643 	if (p)
2644 		return sprintf(page, "%s\n", p->name);
2645 	else if (mddev->clevel[0])
2646 		return sprintf(page, "%s\n", mddev->clevel);
2647 	else if (mddev->level != LEVEL_NONE)
2648 		return sprintf(page, "%d\n", mddev->level);
2649 	else
2650 		return 0;
2651 }
2652 
2653 static ssize_t
2654 level_store(mddev_t *mddev, const char *buf, size_t len)
2655 {
2656 	char level[16];
2657 	ssize_t rv = len;
2658 	struct mdk_personality *pers;
2659 	void *priv;
2660 
2661 	if (mddev->pers == NULL) {
2662 		if (len == 0)
2663 			return 0;
2664 		if (len >= sizeof(mddev->clevel))
2665 			return -ENOSPC;
2666 		strncpy(mddev->clevel, buf, len);
2667 		if (mddev->clevel[len-1] == '\n')
2668 			len--;
2669 		mddev->clevel[len] = 0;
2670 		mddev->level = LEVEL_NONE;
2671 		return rv;
2672 	}
2673 
2674 	/* request to change the personality.  Need to ensure:
2675 	 *  - array is not engaged in resync/recovery/reshape
2676 	 *  - old personality can be suspended
2677 	 *  - new personality will access other array.
2678 	 */
2679 
2680 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
2681 		return -EBUSY;
2682 
2683 	if (!mddev->pers->quiesce) {
2684 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
2685 		       mdname(mddev), mddev->pers->name);
2686 		return -EINVAL;
2687 	}
2688 
2689 	/* Now find the new personality */
2690 	if (len == 0 || len >= sizeof(level))
2691 		return -EINVAL;
2692 	strncpy(level, buf, len);
2693 	if (level[len-1] == '\n')
2694 		len--;
2695 	level[len] = 0;
2696 
2697 	request_module("md-%s", level);
2698 	spin_lock(&pers_lock);
2699 	pers = find_pers(LEVEL_NONE, level);
2700 	if (!pers || !try_module_get(pers->owner)) {
2701 		spin_unlock(&pers_lock);
2702 		printk(KERN_WARNING "md: personality %s not loaded\n", level);
2703 		return -EINVAL;
2704 	}
2705 	spin_unlock(&pers_lock);
2706 
2707 	if (pers == mddev->pers) {
2708 		/* Nothing to do! */
2709 		module_put(pers->owner);
2710 		return rv;
2711 	}
2712 	if (!pers->takeover) {
2713 		module_put(pers->owner);
2714 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
2715 		       mdname(mddev), level);
2716 		return -EINVAL;
2717 	}
2718 
2719 	/* ->takeover must set new_* and/or delta_disks
2720 	 * if it succeeds, and may set them when it fails.
2721 	 */
2722 	priv = pers->takeover(mddev);
2723 	if (IS_ERR(priv)) {
2724 		mddev->new_level = mddev->level;
2725 		mddev->new_layout = mddev->layout;
2726 		mddev->new_chunk_sectors = mddev->chunk_sectors;
2727 		mddev->raid_disks -= mddev->delta_disks;
2728 		mddev->delta_disks = 0;
2729 		module_put(pers->owner);
2730 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
2731 		       mdname(mddev), level);
2732 		return PTR_ERR(priv);
2733 	}
2734 
2735 	/* Looks like we have a winner */
2736 	mddev_suspend(mddev);
2737 	mddev->pers->stop(mddev);
2738 	module_put(mddev->pers->owner);
2739 	mddev->pers = pers;
2740 	mddev->private = priv;
2741 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
2742 	mddev->level = mddev->new_level;
2743 	mddev->layout = mddev->new_layout;
2744 	mddev->chunk_sectors = mddev->new_chunk_sectors;
2745 	mddev->delta_disks = 0;
2746 	pers->run(mddev);
2747 	mddev_resume(mddev);
2748 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
2749 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2750 	md_wakeup_thread(mddev->thread);
2751 	return rv;
2752 }
2753 
2754 static struct md_sysfs_entry md_level =
2755 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
2756 
2757 
2758 static ssize_t
2759 layout_show(mddev_t *mddev, char *page)
2760 {
2761 	/* just a number, not meaningful for all levels */
2762 	if (mddev->reshape_position != MaxSector &&
2763 	    mddev->layout != mddev->new_layout)
2764 		return sprintf(page, "%d (%d)\n",
2765 			       mddev->new_layout, mddev->layout);
2766 	return sprintf(page, "%d\n", mddev->layout);
2767 }
2768 
2769 static ssize_t
2770 layout_store(mddev_t *mddev, const char *buf, size_t len)
2771 {
2772 	char *e;
2773 	unsigned long n = simple_strtoul(buf, &e, 10);
2774 
2775 	if (!*buf || (*e && *e != '\n'))
2776 		return -EINVAL;
2777 
2778 	if (mddev->pers) {
2779 		int err;
2780 		if (mddev->pers->check_reshape == NULL)
2781 			return -EBUSY;
2782 		mddev->new_layout = n;
2783 		err = mddev->pers->check_reshape(mddev);
2784 		if (err) {
2785 			mddev->new_layout = mddev->layout;
2786 			return err;
2787 		}
2788 	} else {
2789 		mddev->new_layout = n;
2790 		if (mddev->reshape_position == MaxSector)
2791 			mddev->layout = n;
2792 	}
2793 	return len;
2794 }
2795 static struct md_sysfs_entry md_layout =
2796 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
2797 
2798 
2799 static ssize_t
2800 raid_disks_show(mddev_t *mddev, char *page)
2801 {
2802 	if (mddev->raid_disks == 0)
2803 		return 0;
2804 	if (mddev->reshape_position != MaxSector &&
2805 	    mddev->delta_disks != 0)
2806 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
2807 			       mddev->raid_disks - mddev->delta_disks);
2808 	return sprintf(page, "%d\n", mddev->raid_disks);
2809 }
2810 
2811 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2812 
2813 static ssize_t
2814 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2815 {
2816 	char *e;
2817 	int rv = 0;
2818 	unsigned long n = simple_strtoul(buf, &e, 10);
2819 
2820 	if (!*buf || (*e && *e != '\n'))
2821 		return -EINVAL;
2822 
2823 	if (mddev->pers)
2824 		rv = update_raid_disks(mddev, n);
2825 	else if (mddev->reshape_position != MaxSector) {
2826 		int olddisks = mddev->raid_disks - mddev->delta_disks;
2827 		mddev->delta_disks = n - olddisks;
2828 		mddev->raid_disks = n;
2829 	} else
2830 		mddev->raid_disks = n;
2831 	return rv ? rv : len;
2832 }
2833 static struct md_sysfs_entry md_raid_disks =
2834 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
2835 
2836 static ssize_t
2837 chunk_size_show(mddev_t *mddev, char *page)
2838 {
2839 	if (mddev->reshape_position != MaxSector &&
2840 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
2841 		return sprintf(page, "%d (%d)\n",
2842 			       mddev->new_chunk_sectors << 9,
2843 			       mddev->chunk_sectors << 9);
2844 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
2845 }
2846 
2847 static ssize_t
2848 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2849 {
2850 	char *e;
2851 	unsigned long n = simple_strtoul(buf, &e, 10);
2852 
2853 	if (!*buf || (*e && *e != '\n'))
2854 		return -EINVAL;
2855 
2856 	if (mddev->pers) {
2857 		int err;
2858 		if (mddev->pers->check_reshape == NULL)
2859 			return -EBUSY;
2860 		mddev->new_chunk_sectors = n >> 9;
2861 		err = mddev->pers->check_reshape(mddev);
2862 		if (err) {
2863 			mddev->new_chunk_sectors = mddev->chunk_sectors;
2864 			return err;
2865 		}
2866 	} else {
2867 		mddev->new_chunk_sectors = n >> 9;
2868 		if (mddev->reshape_position == MaxSector)
2869 			mddev->chunk_sectors = n >> 9;
2870 	}
2871 	return len;
2872 }
2873 static struct md_sysfs_entry md_chunk_size =
2874 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
2875 
2876 static ssize_t
2877 resync_start_show(mddev_t *mddev, char *page)
2878 {
2879 	if (mddev->recovery_cp == MaxSector)
2880 		return sprintf(page, "none\n");
2881 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
2882 }
2883 
2884 static ssize_t
2885 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
2886 {
2887 	char *e;
2888 	unsigned long long n = simple_strtoull(buf, &e, 10);
2889 
2890 	if (mddev->pers)
2891 		return -EBUSY;
2892 	if (!*buf || (*e && *e != '\n'))
2893 		return -EINVAL;
2894 
2895 	mddev->recovery_cp = n;
2896 	return len;
2897 }
2898 static struct md_sysfs_entry md_resync_start =
2899 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
2900 
2901 /*
2902  * The array state can be:
2903  *
2904  * clear
2905  *     No devices, no size, no level
2906  *     Equivalent to STOP_ARRAY ioctl
2907  * inactive
2908  *     May have some settings, but array is not active
2909  *        all IO results in error
2910  *     When written, doesn't tear down array, but just stops it
2911  * suspended (not supported yet)
2912  *     All IO requests will block. The array can be reconfigured.
2913  *     Writing this, if accepted, will block until array is quiescent
2914  * readonly
2915  *     no resync can happen.  no superblocks get written.
2916  *     write requests fail
2917  * read-auto
2918  *     like readonly, but behaves like 'clean' on a write request.
2919  *
2920  * clean - no pending writes, but otherwise active.
2921  *     When written to inactive array, starts without resync
2922  *     If a write request arrives then
2923  *       if metadata is known, mark 'dirty' and switch to 'active'.
2924  *       if not known, block and switch to write-pending
2925  *     If written to an active array that has pending writes, then fails.
2926  * active
2927  *     fully active: IO and resync can be happening.
2928  *     When written to inactive array, starts with resync
2929  *
2930  * write-pending
2931  *     clean, but writes are blocked waiting for 'active' to be written.
2932  *
2933  * active-idle
2934  *     like active, but no writes have been seen for a while (100msec).
2935  *
2936  */
2937 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
2938 		   write_pending, active_idle, bad_word};
2939 static char *array_states[] = {
2940 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
2941 	"write-pending", "active-idle", NULL };
2942 
2943 static int match_word(const char *word, char **list)
2944 {
2945 	int n;
2946 	for (n=0; list[n]; n++)
2947 		if (cmd_match(word, list[n]))
2948 			break;
2949 	return n;
2950 }
2951 
2952 static ssize_t
2953 array_state_show(mddev_t *mddev, char *page)
2954 {
2955 	enum array_state st = inactive;
2956 
2957 	if (mddev->pers)
2958 		switch(mddev->ro) {
2959 		case 1:
2960 			st = readonly;
2961 			break;
2962 		case 2:
2963 			st = read_auto;
2964 			break;
2965 		case 0:
2966 			if (mddev->in_sync)
2967 				st = clean;
2968 			else if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
2969 				st = write_pending;
2970 			else if (mddev->safemode)
2971 				st = active_idle;
2972 			else
2973 				st = active;
2974 		}
2975 	else {
2976 		if (list_empty(&mddev->disks) &&
2977 		    mddev->raid_disks == 0 &&
2978 		    mddev->dev_sectors == 0)
2979 			st = clear;
2980 		else
2981 			st = inactive;
2982 	}
2983 	return sprintf(page, "%s\n", array_states[st]);
2984 }
2985 
2986 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
2987 static int do_md_run(mddev_t * mddev);
2988 static int restart_array(mddev_t *mddev);
2989 
2990 static ssize_t
2991 array_state_store(mddev_t *mddev, const char *buf, size_t len)
2992 {
2993 	int err = -EINVAL;
2994 	enum array_state st = match_word(buf, array_states);
2995 	switch(st) {
2996 	case bad_word:
2997 		break;
2998 	case clear:
2999 		/* stopping an active array */
3000 		if (atomic_read(&mddev->openers) > 0)
3001 			return -EBUSY;
3002 		err = do_md_stop(mddev, 0, 0);
3003 		break;
3004 	case inactive:
3005 		/* stopping an active array */
3006 		if (mddev->pers) {
3007 			if (atomic_read(&mddev->openers) > 0)
3008 				return -EBUSY;
3009 			err = do_md_stop(mddev, 2, 0);
3010 		} else
3011 			err = 0; /* already inactive */
3012 		break;
3013 	case suspended:
3014 		break; /* not supported yet */
3015 	case readonly:
3016 		if (mddev->pers)
3017 			err = do_md_stop(mddev, 1, 0);
3018 		else {
3019 			mddev->ro = 1;
3020 			set_disk_ro(mddev->gendisk, 1);
3021 			err = do_md_run(mddev);
3022 		}
3023 		break;
3024 	case read_auto:
3025 		if (mddev->pers) {
3026 			if (mddev->ro == 0)
3027 				err = do_md_stop(mddev, 1, 0);
3028 			else if (mddev->ro == 1)
3029 				err = restart_array(mddev);
3030 			if (err == 0) {
3031 				mddev->ro = 2;
3032 				set_disk_ro(mddev->gendisk, 0);
3033 			}
3034 		} else {
3035 			mddev->ro = 2;
3036 			err = do_md_run(mddev);
3037 		}
3038 		break;
3039 	case clean:
3040 		if (mddev->pers) {
3041 			restart_array(mddev);
3042 			spin_lock_irq(&mddev->write_lock);
3043 			if (atomic_read(&mddev->writes_pending) == 0) {
3044 				if (mddev->in_sync == 0) {
3045 					mddev->in_sync = 1;
3046 					if (mddev->safemode == 1)
3047 						mddev->safemode = 0;
3048 					if (mddev->persistent)
3049 						set_bit(MD_CHANGE_CLEAN,
3050 							&mddev->flags);
3051 				}
3052 				err = 0;
3053 			} else
3054 				err = -EBUSY;
3055 			spin_unlock_irq(&mddev->write_lock);
3056 		} else
3057 			err = -EINVAL;
3058 		break;
3059 	case active:
3060 		if (mddev->pers) {
3061 			restart_array(mddev);
3062 			if (mddev->external)
3063 				clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
3064 			wake_up(&mddev->sb_wait);
3065 			err = 0;
3066 		} else {
3067 			mddev->ro = 0;
3068 			set_disk_ro(mddev->gendisk, 0);
3069 			err = do_md_run(mddev);
3070 		}
3071 		break;
3072 	case write_pending:
3073 	case active_idle:
3074 		/* these cannot be set */
3075 		break;
3076 	}
3077 	if (err)
3078 		return err;
3079 	else {
3080 		sysfs_notify_dirent(mddev->sysfs_state);
3081 		return len;
3082 	}
3083 }
3084 static struct md_sysfs_entry md_array_state =
3085 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3086 
3087 static ssize_t
3088 null_show(mddev_t *mddev, char *page)
3089 {
3090 	return -EINVAL;
3091 }
3092 
3093 static ssize_t
3094 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3095 {
3096 	/* buf must be %d:%d\n? giving major and minor numbers */
3097 	/* The new device is added to the array.
3098 	 * If the array has a persistent superblock, we read the
3099 	 * superblock to initialise info and check validity.
3100 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3101 	 * which mainly checks size.
3102 	 */
3103 	char *e;
3104 	int major = simple_strtoul(buf, &e, 10);
3105 	int minor;
3106 	dev_t dev;
3107 	mdk_rdev_t *rdev;
3108 	int err;
3109 
3110 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3111 		return -EINVAL;
3112 	minor = simple_strtoul(e+1, &e, 10);
3113 	if (*e && *e != '\n')
3114 		return -EINVAL;
3115 	dev = MKDEV(major, minor);
3116 	if (major != MAJOR(dev) ||
3117 	    minor != MINOR(dev))
3118 		return -EOVERFLOW;
3119 
3120 
3121 	if (mddev->persistent) {
3122 		rdev = md_import_device(dev, mddev->major_version,
3123 					mddev->minor_version);
3124 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3125 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3126 						       mdk_rdev_t, same_set);
3127 			err = super_types[mddev->major_version]
3128 				.load_super(rdev, rdev0, mddev->minor_version);
3129 			if (err < 0)
3130 				goto out;
3131 		}
3132 	} else if (mddev->external)
3133 		rdev = md_import_device(dev, -2, -1);
3134 	else
3135 		rdev = md_import_device(dev, -1, -1);
3136 
3137 	if (IS_ERR(rdev))
3138 		return PTR_ERR(rdev);
3139 	err = bind_rdev_to_array(rdev, mddev);
3140  out:
3141 	if (err)
3142 		export_rdev(rdev);
3143 	return err ? err : len;
3144 }
3145 
3146 static struct md_sysfs_entry md_new_device =
3147 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3148 
3149 static ssize_t
3150 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3151 {
3152 	char *end;
3153 	unsigned long chunk, end_chunk;
3154 
3155 	if (!mddev->bitmap)
3156 		goto out;
3157 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3158 	while (*buf) {
3159 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3160 		if (buf == end) break;
3161 		if (*end == '-') { /* range */
3162 			buf = end + 1;
3163 			end_chunk = simple_strtoul(buf, &end, 0);
3164 			if (buf == end) break;
3165 		}
3166 		if (*end && !isspace(*end)) break;
3167 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3168 		buf = end;
3169 		while (isspace(*buf)) buf++;
3170 	}
3171 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3172 out:
3173 	return len;
3174 }
3175 
3176 static struct md_sysfs_entry md_bitmap =
3177 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3178 
3179 static ssize_t
3180 size_show(mddev_t *mddev, char *page)
3181 {
3182 	return sprintf(page, "%llu\n",
3183 		(unsigned long long)mddev->dev_sectors / 2);
3184 }
3185 
3186 static int update_size(mddev_t *mddev, sector_t num_sectors);
3187 
3188 static ssize_t
3189 size_store(mddev_t *mddev, const char *buf, size_t len)
3190 {
3191 	/* If array is inactive, we can reduce the component size, but
3192 	 * not increase it (except from 0).
3193 	 * If array is active, we can try an on-line resize
3194 	 */
3195 	sector_t sectors;
3196 	int err = strict_blocks_to_sectors(buf, &sectors);
3197 
3198 	if (err < 0)
3199 		return err;
3200 	if (mddev->pers) {
3201 		err = update_size(mddev, sectors);
3202 		md_update_sb(mddev, 1);
3203 	} else {
3204 		if (mddev->dev_sectors == 0 ||
3205 		    mddev->dev_sectors > sectors)
3206 			mddev->dev_sectors = sectors;
3207 		else
3208 			err = -ENOSPC;
3209 	}
3210 	return err ? err : len;
3211 }
3212 
3213 static struct md_sysfs_entry md_size =
3214 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3215 
3216 
3217 /* Metdata version.
3218  * This is one of
3219  *   'none' for arrays with no metadata (good luck...)
3220  *   'external' for arrays with externally managed metadata,
3221  * or N.M for internally known formats
3222  */
3223 static ssize_t
3224 metadata_show(mddev_t *mddev, char *page)
3225 {
3226 	if (mddev->persistent)
3227 		return sprintf(page, "%d.%d\n",
3228 			       mddev->major_version, mddev->minor_version);
3229 	else if (mddev->external)
3230 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3231 	else
3232 		return sprintf(page, "none\n");
3233 }
3234 
3235 static ssize_t
3236 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3237 {
3238 	int major, minor;
3239 	char *e;
3240 	/* Changing the details of 'external' metadata is
3241 	 * always permitted.  Otherwise there must be
3242 	 * no devices attached to the array.
3243 	 */
3244 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3245 		;
3246 	else if (!list_empty(&mddev->disks))
3247 		return -EBUSY;
3248 
3249 	if (cmd_match(buf, "none")) {
3250 		mddev->persistent = 0;
3251 		mddev->external = 0;
3252 		mddev->major_version = 0;
3253 		mddev->minor_version = 90;
3254 		return len;
3255 	}
3256 	if (strncmp(buf, "external:", 9) == 0) {
3257 		size_t namelen = len-9;
3258 		if (namelen >= sizeof(mddev->metadata_type))
3259 			namelen = sizeof(mddev->metadata_type)-1;
3260 		strncpy(mddev->metadata_type, buf+9, namelen);
3261 		mddev->metadata_type[namelen] = 0;
3262 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3263 			mddev->metadata_type[--namelen] = 0;
3264 		mddev->persistent = 0;
3265 		mddev->external = 1;
3266 		mddev->major_version = 0;
3267 		mddev->minor_version = 90;
3268 		return len;
3269 	}
3270 	major = simple_strtoul(buf, &e, 10);
3271 	if (e==buf || *e != '.')
3272 		return -EINVAL;
3273 	buf = e+1;
3274 	minor = simple_strtoul(buf, &e, 10);
3275 	if (e==buf || (*e && *e != '\n') )
3276 		return -EINVAL;
3277 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3278 		return -ENOENT;
3279 	mddev->major_version = major;
3280 	mddev->minor_version = minor;
3281 	mddev->persistent = 1;
3282 	mddev->external = 0;
3283 	return len;
3284 }
3285 
3286 static struct md_sysfs_entry md_metadata =
3287 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3288 
3289 static ssize_t
3290 action_show(mddev_t *mddev, char *page)
3291 {
3292 	char *type = "idle";
3293 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3294 		type = "frozen";
3295 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3296 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3297 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3298 			type = "reshape";
3299 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3300 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3301 				type = "resync";
3302 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3303 				type = "check";
3304 			else
3305 				type = "repair";
3306 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3307 			type = "recover";
3308 	}
3309 	return sprintf(page, "%s\n", type);
3310 }
3311 
3312 static ssize_t
3313 action_store(mddev_t *mddev, const char *page, size_t len)
3314 {
3315 	if (!mddev->pers || !mddev->pers->sync_request)
3316 		return -EINVAL;
3317 
3318 	if (cmd_match(page, "frozen"))
3319 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3320 	else
3321 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3322 
3323 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
3324 		if (mddev->sync_thread) {
3325 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3326 			md_unregister_thread(mddev->sync_thread);
3327 			mddev->sync_thread = NULL;
3328 			mddev->recovery = 0;
3329 		}
3330 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3331 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3332 		return -EBUSY;
3333 	else if (cmd_match(page, "resync"))
3334 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3335 	else if (cmd_match(page, "recover")) {
3336 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3337 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3338 	} else if (cmd_match(page, "reshape")) {
3339 		int err;
3340 		if (mddev->pers->start_reshape == NULL)
3341 			return -EINVAL;
3342 		err = mddev->pers->start_reshape(mddev);
3343 		if (err)
3344 			return err;
3345 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3346 	} else {
3347 		if (cmd_match(page, "check"))
3348 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3349 		else if (!cmd_match(page, "repair"))
3350 			return -EINVAL;
3351 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3352 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3353 	}
3354 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3355 	md_wakeup_thread(mddev->thread);
3356 	sysfs_notify_dirent(mddev->sysfs_action);
3357 	return len;
3358 }
3359 
3360 static ssize_t
3361 mismatch_cnt_show(mddev_t *mddev, char *page)
3362 {
3363 	return sprintf(page, "%llu\n",
3364 		       (unsigned long long) mddev->resync_mismatches);
3365 }
3366 
3367 static struct md_sysfs_entry md_scan_mode =
3368 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3369 
3370 
3371 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3372 
3373 static ssize_t
3374 sync_min_show(mddev_t *mddev, char *page)
3375 {
3376 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3377 		       mddev->sync_speed_min ? "local": "system");
3378 }
3379 
3380 static ssize_t
3381 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3382 {
3383 	int min;
3384 	char *e;
3385 	if (strncmp(buf, "system", 6)==0) {
3386 		mddev->sync_speed_min = 0;
3387 		return len;
3388 	}
3389 	min = simple_strtoul(buf, &e, 10);
3390 	if (buf == e || (*e && *e != '\n') || min <= 0)
3391 		return -EINVAL;
3392 	mddev->sync_speed_min = min;
3393 	return len;
3394 }
3395 
3396 static struct md_sysfs_entry md_sync_min =
3397 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3398 
3399 static ssize_t
3400 sync_max_show(mddev_t *mddev, char *page)
3401 {
3402 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3403 		       mddev->sync_speed_max ? "local": "system");
3404 }
3405 
3406 static ssize_t
3407 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3408 {
3409 	int max;
3410 	char *e;
3411 	if (strncmp(buf, "system", 6)==0) {
3412 		mddev->sync_speed_max = 0;
3413 		return len;
3414 	}
3415 	max = simple_strtoul(buf, &e, 10);
3416 	if (buf == e || (*e && *e != '\n') || max <= 0)
3417 		return -EINVAL;
3418 	mddev->sync_speed_max = max;
3419 	return len;
3420 }
3421 
3422 static struct md_sysfs_entry md_sync_max =
3423 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3424 
3425 static ssize_t
3426 degraded_show(mddev_t *mddev, char *page)
3427 {
3428 	return sprintf(page, "%d\n", mddev->degraded);
3429 }
3430 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3431 
3432 static ssize_t
3433 sync_force_parallel_show(mddev_t *mddev, char *page)
3434 {
3435 	return sprintf(page, "%d\n", mddev->parallel_resync);
3436 }
3437 
3438 static ssize_t
3439 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3440 {
3441 	long n;
3442 
3443 	if (strict_strtol(buf, 10, &n))
3444 		return -EINVAL;
3445 
3446 	if (n != 0 && n != 1)
3447 		return -EINVAL;
3448 
3449 	mddev->parallel_resync = n;
3450 
3451 	if (mddev->sync_thread)
3452 		wake_up(&resync_wait);
3453 
3454 	return len;
3455 }
3456 
3457 /* force parallel resync, even with shared block devices */
3458 static struct md_sysfs_entry md_sync_force_parallel =
3459 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3460        sync_force_parallel_show, sync_force_parallel_store);
3461 
3462 static ssize_t
3463 sync_speed_show(mddev_t *mddev, char *page)
3464 {
3465 	unsigned long resync, dt, db;
3466 	if (mddev->curr_resync == 0)
3467 		return sprintf(page, "none\n");
3468 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3469 	dt = (jiffies - mddev->resync_mark) / HZ;
3470 	if (!dt) dt++;
3471 	db = resync - mddev->resync_mark_cnt;
3472 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3473 }
3474 
3475 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3476 
3477 static ssize_t
3478 sync_completed_show(mddev_t *mddev, char *page)
3479 {
3480 	unsigned long max_sectors, resync;
3481 
3482 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3483 		return sprintf(page, "none\n");
3484 
3485 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3486 		max_sectors = mddev->resync_max_sectors;
3487 	else
3488 		max_sectors = mddev->dev_sectors;
3489 
3490 	resync = mddev->curr_resync_completed;
3491 	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
3492 }
3493 
3494 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3495 
3496 static ssize_t
3497 min_sync_show(mddev_t *mddev, char *page)
3498 {
3499 	return sprintf(page, "%llu\n",
3500 		       (unsigned long long)mddev->resync_min);
3501 }
3502 static ssize_t
3503 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3504 {
3505 	unsigned long long min;
3506 	if (strict_strtoull(buf, 10, &min))
3507 		return -EINVAL;
3508 	if (min > mddev->resync_max)
3509 		return -EINVAL;
3510 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3511 		return -EBUSY;
3512 
3513 	/* Must be a multiple of chunk_size */
3514 	if (mddev->chunk_sectors) {
3515 		sector_t temp = min;
3516 		if (sector_div(temp, mddev->chunk_sectors))
3517 			return -EINVAL;
3518 	}
3519 	mddev->resync_min = min;
3520 
3521 	return len;
3522 }
3523 
3524 static struct md_sysfs_entry md_min_sync =
3525 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3526 
3527 static ssize_t
3528 max_sync_show(mddev_t *mddev, char *page)
3529 {
3530 	if (mddev->resync_max == MaxSector)
3531 		return sprintf(page, "max\n");
3532 	else
3533 		return sprintf(page, "%llu\n",
3534 			       (unsigned long long)mddev->resync_max);
3535 }
3536 static ssize_t
3537 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3538 {
3539 	if (strncmp(buf, "max", 3) == 0)
3540 		mddev->resync_max = MaxSector;
3541 	else {
3542 		unsigned long long max;
3543 		if (strict_strtoull(buf, 10, &max))
3544 			return -EINVAL;
3545 		if (max < mddev->resync_min)
3546 			return -EINVAL;
3547 		if (max < mddev->resync_max &&
3548 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3549 			return -EBUSY;
3550 
3551 		/* Must be a multiple of chunk_size */
3552 		if (mddev->chunk_sectors) {
3553 			sector_t temp = max;
3554 			if (sector_div(temp, mddev->chunk_sectors))
3555 				return -EINVAL;
3556 		}
3557 		mddev->resync_max = max;
3558 	}
3559 	wake_up(&mddev->recovery_wait);
3560 	return len;
3561 }
3562 
3563 static struct md_sysfs_entry md_max_sync =
3564 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
3565 
3566 static ssize_t
3567 suspend_lo_show(mddev_t *mddev, char *page)
3568 {
3569 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
3570 }
3571 
3572 static ssize_t
3573 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
3574 {
3575 	char *e;
3576 	unsigned long long new = simple_strtoull(buf, &e, 10);
3577 
3578 	if (mddev->pers == NULL ||
3579 	    mddev->pers->quiesce == NULL)
3580 		return -EINVAL;
3581 	if (buf == e || (*e && *e != '\n'))
3582 		return -EINVAL;
3583 	if (new >= mddev->suspend_hi ||
3584 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
3585 		mddev->suspend_lo = new;
3586 		mddev->pers->quiesce(mddev, 2);
3587 		return len;
3588 	} else
3589 		return -EINVAL;
3590 }
3591 static struct md_sysfs_entry md_suspend_lo =
3592 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
3593 
3594 
3595 static ssize_t
3596 suspend_hi_show(mddev_t *mddev, char *page)
3597 {
3598 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
3599 }
3600 
3601 static ssize_t
3602 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
3603 {
3604 	char *e;
3605 	unsigned long long new = simple_strtoull(buf, &e, 10);
3606 
3607 	if (mddev->pers == NULL ||
3608 	    mddev->pers->quiesce == NULL)
3609 		return -EINVAL;
3610 	if (buf == e || (*e && *e != '\n'))
3611 		return -EINVAL;
3612 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
3613 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
3614 		mddev->suspend_hi = new;
3615 		mddev->pers->quiesce(mddev, 1);
3616 		mddev->pers->quiesce(mddev, 0);
3617 		return len;
3618 	} else
3619 		return -EINVAL;
3620 }
3621 static struct md_sysfs_entry md_suspend_hi =
3622 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
3623 
3624 static ssize_t
3625 reshape_position_show(mddev_t *mddev, char *page)
3626 {
3627 	if (mddev->reshape_position != MaxSector)
3628 		return sprintf(page, "%llu\n",
3629 			       (unsigned long long)mddev->reshape_position);
3630 	strcpy(page, "none\n");
3631 	return 5;
3632 }
3633 
3634 static ssize_t
3635 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
3636 {
3637 	char *e;
3638 	unsigned long long new = simple_strtoull(buf, &e, 10);
3639 	if (mddev->pers)
3640 		return -EBUSY;
3641 	if (buf == e || (*e && *e != '\n'))
3642 		return -EINVAL;
3643 	mddev->reshape_position = new;
3644 	mddev->delta_disks = 0;
3645 	mddev->new_level = mddev->level;
3646 	mddev->new_layout = mddev->layout;
3647 	mddev->new_chunk_sectors = mddev->chunk_sectors;
3648 	return len;
3649 }
3650 
3651 static struct md_sysfs_entry md_reshape_position =
3652 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
3653        reshape_position_store);
3654 
3655 static ssize_t
3656 array_size_show(mddev_t *mddev, char *page)
3657 {
3658 	if (mddev->external_size)
3659 		return sprintf(page, "%llu\n",
3660 			       (unsigned long long)mddev->array_sectors/2);
3661 	else
3662 		return sprintf(page, "default\n");
3663 }
3664 
3665 static ssize_t
3666 array_size_store(mddev_t *mddev, const char *buf, size_t len)
3667 {
3668 	sector_t sectors;
3669 
3670 	if (strncmp(buf, "default", 7) == 0) {
3671 		if (mddev->pers)
3672 			sectors = mddev->pers->size(mddev, 0, 0);
3673 		else
3674 			sectors = mddev->array_sectors;
3675 
3676 		mddev->external_size = 0;
3677 	} else {
3678 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
3679 			return -EINVAL;
3680 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
3681 			return -E2BIG;
3682 
3683 		mddev->external_size = 1;
3684 	}
3685 
3686 	mddev->array_sectors = sectors;
3687 	set_capacity(mddev->gendisk, mddev->array_sectors);
3688 	if (mddev->pers) {
3689 		struct block_device *bdev = bdget_disk(mddev->gendisk, 0);
3690 
3691 		if (bdev) {
3692 			mutex_lock(&bdev->bd_inode->i_mutex);
3693 			i_size_write(bdev->bd_inode,
3694 				     (loff_t)mddev->array_sectors << 9);
3695 			mutex_unlock(&bdev->bd_inode->i_mutex);
3696 			bdput(bdev);
3697 		}
3698 	}
3699 
3700 	return len;
3701 }
3702 
3703 static struct md_sysfs_entry md_array_size =
3704 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
3705        array_size_store);
3706 
3707 static struct attribute *md_default_attrs[] = {
3708 	&md_level.attr,
3709 	&md_layout.attr,
3710 	&md_raid_disks.attr,
3711 	&md_chunk_size.attr,
3712 	&md_size.attr,
3713 	&md_resync_start.attr,
3714 	&md_metadata.attr,
3715 	&md_new_device.attr,
3716 	&md_safe_delay.attr,
3717 	&md_array_state.attr,
3718 	&md_reshape_position.attr,
3719 	&md_array_size.attr,
3720 	NULL,
3721 };
3722 
3723 static struct attribute *md_redundancy_attrs[] = {
3724 	&md_scan_mode.attr,
3725 	&md_mismatches.attr,
3726 	&md_sync_min.attr,
3727 	&md_sync_max.attr,
3728 	&md_sync_speed.attr,
3729 	&md_sync_force_parallel.attr,
3730 	&md_sync_completed.attr,
3731 	&md_min_sync.attr,
3732 	&md_max_sync.attr,
3733 	&md_suspend_lo.attr,
3734 	&md_suspend_hi.attr,
3735 	&md_bitmap.attr,
3736 	&md_degraded.attr,
3737 	NULL,
3738 };
3739 static struct attribute_group md_redundancy_group = {
3740 	.name = NULL,
3741 	.attrs = md_redundancy_attrs,
3742 };
3743 
3744 
3745 static ssize_t
3746 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3747 {
3748 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3749 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3750 	ssize_t rv;
3751 
3752 	if (!entry->show)
3753 		return -EIO;
3754 	rv = mddev_lock(mddev);
3755 	if (!rv) {
3756 		rv = entry->show(mddev, page);
3757 		mddev_unlock(mddev);
3758 	}
3759 	return rv;
3760 }
3761 
3762 static ssize_t
3763 md_attr_store(struct kobject *kobj, struct attribute *attr,
3764 	      const char *page, size_t length)
3765 {
3766 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3767 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3768 	ssize_t rv;
3769 
3770 	if (!entry->store)
3771 		return -EIO;
3772 	if (!capable(CAP_SYS_ADMIN))
3773 		return -EACCES;
3774 	rv = mddev_lock(mddev);
3775 	if (mddev->hold_active == UNTIL_IOCTL)
3776 		mddev->hold_active = 0;
3777 	if (!rv) {
3778 		rv = entry->store(mddev, page, length);
3779 		mddev_unlock(mddev);
3780 	}
3781 	return rv;
3782 }
3783 
3784 static void md_free(struct kobject *ko)
3785 {
3786 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
3787 
3788 	if (mddev->sysfs_state)
3789 		sysfs_put(mddev->sysfs_state);
3790 
3791 	if (mddev->gendisk) {
3792 		del_gendisk(mddev->gendisk);
3793 		put_disk(mddev->gendisk);
3794 	}
3795 	if (mddev->queue)
3796 		blk_cleanup_queue(mddev->queue);
3797 
3798 	kfree(mddev);
3799 }
3800 
3801 static struct sysfs_ops md_sysfs_ops = {
3802 	.show	= md_attr_show,
3803 	.store	= md_attr_store,
3804 };
3805 static struct kobj_type md_ktype = {
3806 	.release	= md_free,
3807 	.sysfs_ops	= &md_sysfs_ops,
3808 	.default_attrs	= md_default_attrs,
3809 };
3810 
3811 int mdp_major = 0;
3812 
3813 static void mddev_delayed_delete(struct work_struct *ws)
3814 {
3815 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
3816 
3817 	if (mddev->private == &md_redundancy_group) {
3818 		sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
3819 		if (mddev->sysfs_action)
3820 			sysfs_put(mddev->sysfs_action);
3821 		mddev->sysfs_action = NULL;
3822 		mddev->private = NULL;
3823 	}
3824 	kobject_del(&mddev->kobj);
3825 	kobject_put(&mddev->kobj);
3826 }
3827 
3828 static int md_alloc(dev_t dev, char *name)
3829 {
3830 	static DEFINE_MUTEX(disks_mutex);
3831 	mddev_t *mddev = mddev_find(dev);
3832 	struct gendisk *disk;
3833 	int partitioned;
3834 	int shift;
3835 	int unit;
3836 	int error;
3837 
3838 	if (!mddev)
3839 		return -ENODEV;
3840 
3841 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
3842 	shift = partitioned ? MdpMinorShift : 0;
3843 	unit = MINOR(mddev->unit) >> shift;
3844 
3845 	/* wait for any previous instance if this device
3846 	 * to be completed removed (mddev_delayed_delete).
3847 	 */
3848 	flush_scheduled_work();
3849 
3850 	mutex_lock(&disks_mutex);
3851 	error = -EEXIST;
3852 	if (mddev->gendisk)
3853 		goto abort;
3854 
3855 	if (name) {
3856 		/* Need to ensure that 'name' is not a duplicate.
3857 		 */
3858 		mddev_t *mddev2;
3859 		spin_lock(&all_mddevs_lock);
3860 
3861 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
3862 			if (mddev2->gendisk &&
3863 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
3864 				spin_unlock(&all_mddevs_lock);
3865 				goto abort;
3866 			}
3867 		spin_unlock(&all_mddevs_lock);
3868 	}
3869 
3870 	error = -ENOMEM;
3871 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
3872 	if (!mddev->queue)
3873 		goto abort;
3874 	mddev->queue->queuedata = mddev;
3875 
3876 	/* Can be unlocked because the queue is new: no concurrency */
3877 	queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
3878 
3879 	blk_queue_make_request(mddev->queue, md_make_request);
3880 
3881 	disk = alloc_disk(1 << shift);
3882 	if (!disk) {
3883 		blk_cleanup_queue(mddev->queue);
3884 		mddev->queue = NULL;
3885 		goto abort;
3886 	}
3887 	disk->major = MAJOR(mddev->unit);
3888 	disk->first_minor = unit << shift;
3889 	if (name)
3890 		strcpy(disk->disk_name, name);
3891 	else if (partitioned)
3892 		sprintf(disk->disk_name, "md_d%d", unit);
3893 	else
3894 		sprintf(disk->disk_name, "md%d", unit);
3895 	disk->fops = &md_fops;
3896 	disk->private_data = mddev;
3897 	disk->queue = mddev->queue;
3898 	/* Allow extended partitions.  This makes the
3899 	 * 'mdp' device redundant, but we can't really
3900 	 * remove it now.
3901 	 */
3902 	disk->flags |= GENHD_FL_EXT_DEVT;
3903 	add_disk(disk);
3904 	mddev->gendisk = disk;
3905 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
3906 				     &disk_to_dev(disk)->kobj, "%s", "md");
3907 	if (error) {
3908 		/* This isn't possible, but as kobject_init_and_add is marked
3909 		 * __must_check, we must do something with the result
3910 		 */
3911 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
3912 		       disk->disk_name);
3913 		error = 0;
3914 	}
3915  abort:
3916 	mutex_unlock(&disks_mutex);
3917 	if (!error) {
3918 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
3919 		mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
3920 	}
3921 	mddev_put(mddev);
3922 	return error;
3923 }
3924 
3925 static struct kobject *md_probe(dev_t dev, int *part, void *data)
3926 {
3927 	md_alloc(dev, NULL);
3928 	return NULL;
3929 }
3930 
3931 static int add_named_array(const char *val, struct kernel_param *kp)
3932 {
3933 	/* val must be "md_*" where * is not all digits.
3934 	 * We allocate an array with a large free minor number, and
3935 	 * set the name to val.  val must not already be an active name.
3936 	 */
3937 	int len = strlen(val);
3938 	char buf[DISK_NAME_LEN];
3939 
3940 	while (len && val[len-1] == '\n')
3941 		len--;
3942 	if (len >= DISK_NAME_LEN)
3943 		return -E2BIG;
3944 	strlcpy(buf, val, len+1);
3945 	if (strncmp(buf, "md_", 3) != 0)
3946 		return -EINVAL;
3947 	return md_alloc(0, buf);
3948 }
3949 
3950 static void md_safemode_timeout(unsigned long data)
3951 {
3952 	mddev_t *mddev = (mddev_t *) data;
3953 
3954 	if (!atomic_read(&mddev->writes_pending)) {
3955 		mddev->safemode = 1;
3956 		if (mddev->external)
3957 			sysfs_notify_dirent(mddev->sysfs_state);
3958 	}
3959 	md_wakeup_thread(mddev->thread);
3960 }
3961 
3962 static int start_dirty_degraded;
3963 
3964 static int do_md_run(mddev_t * mddev)
3965 {
3966 	int err;
3967 	mdk_rdev_t *rdev;
3968 	struct gendisk *disk;
3969 	struct mdk_personality *pers;
3970 
3971 	if (list_empty(&mddev->disks))
3972 		/* cannot run an array with no devices.. */
3973 		return -EINVAL;
3974 
3975 	if (mddev->pers)
3976 		return -EBUSY;
3977 
3978 	/*
3979 	 * Analyze all RAID superblock(s)
3980 	 */
3981 	if (!mddev->raid_disks) {
3982 		if (!mddev->persistent)
3983 			return -EINVAL;
3984 		analyze_sbs(mddev);
3985 	}
3986 
3987 	if (mddev->level != LEVEL_NONE)
3988 		request_module("md-level-%d", mddev->level);
3989 	else if (mddev->clevel[0])
3990 		request_module("md-%s", mddev->clevel);
3991 
3992 	/*
3993 	 * Drop all container device buffers, from now on
3994 	 * the only valid external interface is through the md
3995 	 * device.
3996 	 */
3997 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3998 		if (test_bit(Faulty, &rdev->flags))
3999 			continue;
4000 		sync_blockdev(rdev->bdev);
4001 		invalidate_bdev(rdev->bdev);
4002 
4003 		/* perform some consistency tests on the device.
4004 		 * We don't want the data to overlap the metadata,
4005 		 * Internal Bitmap issues have been handled elsewhere.
4006 		 */
4007 		if (rdev->data_offset < rdev->sb_start) {
4008 			if (mddev->dev_sectors &&
4009 			    rdev->data_offset + mddev->dev_sectors
4010 			    > rdev->sb_start) {
4011 				printk("md: %s: data overlaps metadata\n",
4012 				       mdname(mddev));
4013 				return -EINVAL;
4014 			}
4015 		} else {
4016 			if (rdev->sb_start + rdev->sb_size/512
4017 			    > rdev->data_offset) {
4018 				printk("md: %s: metadata overlaps data\n",
4019 				       mdname(mddev));
4020 				return -EINVAL;
4021 			}
4022 		}
4023 		sysfs_notify_dirent(rdev->sysfs_state);
4024 	}
4025 
4026 	md_probe(mddev->unit, NULL, NULL);
4027 	disk = mddev->gendisk;
4028 	if (!disk)
4029 		return -ENOMEM;
4030 
4031 	spin_lock(&pers_lock);
4032 	pers = find_pers(mddev->level, mddev->clevel);
4033 	if (!pers || !try_module_get(pers->owner)) {
4034 		spin_unlock(&pers_lock);
4035 		if (mddev->level != LEVEL_NONE)
4036 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4037 			       mddev->level);
4038 		else
4039 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4040 			       mddev->clevel);
4041 		return -EINVAL;
4042 	}
4043 	mddev->pers = pers;
4044 	spin_unlock(&pers_lock);
4045 	if (mddev->level != pers->level) {
4046 		mddev->level = pers->level;
4047 		mddev->new_level = pers->level;
4048 	}
4049 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4050 
4051 	if (pers->level >= 4 && pers->level <= 6)
4052 		/* Cannot support integrity (yet) */
4053 		blk_integrity_unregister(mddev->gendisk);
4054 
4055 	if (mddev->reshape_position != MaxSector &&
4056 	    pers->start_reshape == NULL) {
4057 		/* This personality cannot handle reshaping... */
4058 		mddev->pers = NULL;
4059 		module_put(pers->owner);
4060 		return -EINVAL;
4061 	}
4062 
4063 	if (pers->sync_request) {
4064 		/* Warn if this is a potentially silly
4065 		 * configuration.
4066 		 */
4067 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4068 		mdk_rdev_t *rdev2;
4069 		int warned = 0;
4070 
4071 		list_for_each_entry(rdev, &mddev->disks, same_set)
4072 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4073 				if (rdev < rdev2 &&
4074 				    rdev->bdev->bd_contains ==
4075 				    rdev2->bdev->bd_contains) {
4076 					printk(KERN_WARNING
4077 					       "%s: WARNING: %s appears to be"
4078 					       " on the same physical disk as"
4079 					       " %s.\n",
4080 					       mdname(mddev),
4081 					       bdevname(rdev->bdev,b),
4082 					       bdevname(rdev2->bdev,b2));
4083 					warned = 1;
4084 				}
4085 			}
4086 
4087 		if (warned)
4088 			printk(KERN_WARNING
4089 			       "True protection against single-disk"
4090 			       " failure might be compromised.\n");
4091 	}
4092 
4093 	mddev->recovery = 0;
4094 	/* may be over-ridden by personality */
4095 	mddev->resync_max_sectors = mddev->dev_sectors;
4096 
4097 	mddev->barriers_work = 1;
4098 	mddev->ok_start_degraded = start_dirty_degraded;
4099 
4100 	if (start_readonly)
4101 		mddev->ro = 2; /* read-only, but switch on first write */
4102 
4103 	err = mddev->pers->run(mddev);
4104 	if (err)
4105 		printk(KERN_ERR "md: pers->run() failed ...\n");
4106 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4107 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4108 			  " but 'external_size' not in effect?\n", __func__);
4109 		printk(KERN_ERR
4110 		       "md: invalid array_size %llu > default size %llu\n",
4111 		       (unsigned long long)mddev->array_sectors / 2,
4112 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4113 		err = -EINVAL;
4114 		mddev->pers->stop(mddev);
4115 	}
4116 	if (err == 0 && mddev->pers->sync_request) {
4117 		err = bitmap_create(mddev);
4118 		if (err) {
4119 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4120 			       mdname(mddev), err);
4121 			mddev->pers->stop(mddev);
4122 		}
4123 	}
4124 	if (err) {
4125 		module_put(mddev->pers->owner);
4126 		mddev->pers = NULL;
4127 		bitmap_destroy(mddev);
4128 		return err;
4129 	}
4130 	if (mddev->pers->sync_request) {
4131 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4132 			printk(KERN_WARNING
4133 			       "md: cannot register extra attributes for %s\n",
4134 			       mdname(mddev));
4135 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
4136 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4137 		mddev->ro = 0;
4138 
4139  	atomic_set(&mddev->writes_pending,0);
4140 	mddev->safemode = 0;
4141 	mddev->safemode_timer.function = md_safemode_timeout;
4142 	mddev->safemode_timer.data = (unsigned long) mddev;
4143 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4144 	mddev->in_sync = 1;
4145 
4146 	list_for_each_entry(rdev, &mddev->disks, same_set)
4147 		if (rdev->raid_disk >= 0) {
4148 			char nm[20];
4149 			sprintf(nm, "rd%d", rdev->raid_disk);
4150 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
4151 				printk("md: cannot register %s for %s\n",
4152 				       nm, mdname(mddev));
4153 		}
4154 
4155 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4156 
4157 	if (mddev->flags)
4158 		md_update_sb(mddev, 0);
4159 
4160 	set_capacity(disk, mddev->array_sectors);
4161 
4162 	/* If there is a partially-recovered drive we need to
4163 	 * start recovery here.  If we leave it to md_check_recovery,
4164 	 * it will remove the drives and not do the right thing
4165 	 */
4166 	if (mddev->degraded && !mddev->sync_thread) {
4167 		int spares = 0;
4168 		list_for_each_entry(rdev, &mddev->disks, same_set)
4169 			if (rdev->raid_disk >= 0 &&
4170 			    !test_bit(In_sync, &rdev->flags) &&
4171 			    !test_bit(Faulty, &rdev->flags))
4172 				/* complete an interrupted recovery */
4173 				spares++;
4174 		if (spares && mddev->pers->sync_request) {
4175 			mddev->recovery = 0;
4176 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4177 			mddev->sync_thread = md_register_thread(md_do_sync,
4178 								mddev,
4179 								"%s_resync");
4180 			if (!mddev->sync_thread) {
4181 				printk(KERN_ERR "%s: could not start resync"
4182 				       " thread...\n",
4183 				       mdname(mddev));
4184 				/* leave the spares where they are, it shouldn't hurt */
4185 				mddev->recovery = 0;
4186 			}
4187 		}
4188 	}
4189 	md_wakeup_thread(mddev->thread);
4190 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4191 
4192 	mddev->changed = 1;
4193 	md_new_event(mddev);
4194 	sysfs_notify_dirent(mddev->sysfs_state);
4195 	if (mddev->sysfs_action)
4196 		sysfs_notify_dirent(mddev->sysfs_action);
4197 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4198 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4199 	return 0;
4200 }
4201 
4202 static int restart_array(mddev_t *mddev)
4203 {
4204 	struct gendisk *disk = mddev->gendisk;
4205 
4206 	/* Complain if it has no devices */
4207 	if (list_empty(&mddev->disks))
4208 		return -ENXIO;
4209 	if (!mddev->pers)
4210 		return -EINVAL;
4211 	if (!mddev->ro)
4212 		return -EBUSY;
4213 	mddev->safemode = 0;
4214 	mddev->ro = 0;
4215 	set_disk_ro(disk, 0);
4216 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4217 		mdname(mddev));
4218 	/* Kick recovery or resync if necessary */
4219 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4220 	md_wakeup_thread(mddev->thread);
4221 	md_wakeup_thread(mddev->sync_thread);
4222 	sysfs_notify_dirent(mddev->sysfs_state);
4223 	return 0;
4224 }
4225 
4226 /* similar to deny_write_access, but accounts for our holding a reference
4227  * to the file ourselves */
4228 static int deny_bitmap_write_access(struct file * file)
4229 {
4230 	struct inode *inode = file->f_mapping->host;
4231 
4232 	spin_lock(&inode->i_lock);
4233 	if (atomic_read(&inode->i_writecount) > 1) {
4234 		spin_unlock(&inode->i_lock);
4235 		return -ETXTBSY;
4236 	}
4237 	atomic_set(&inode->i_writecount, -1);
4238 	spin_unlock(&inode->i_lock);
4239 
4240 	return 0;
4241 }
4242 
4243 static void restore_bitmap_write_access(struct file *file)
4244 {
4245 	struct inode *inode = file->f_mapping->host;
4246 
4247 	spin_lock(&inode->i_lock);
4248 	atomic_set(&inode->i_writecount, 1);
4249 	spin_unlock(&inode->i_lock);
4250 }
4251 
4252 /* mode:
4253  *   0 - completely stop and dis-assemble array
4254  *   1 - switch to readonly
4255  *   2 - stop but do not disassemble array
4256  */
4257 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4258 {
4259 	int err = 0;
4260 	struct gendisk *disk = mddev->gendisk;
4261 	mdk_rdev_t *rdev;
4262 
4263 	if (atomic_read(&mddev->openers) > is_open) {
4264 		printk("md: %s still in use.\n",mdname(mddev));
4265 		return -EBUSY;
4266 	}
4267 
4268 	if (mddev->pers) {
4269 
4270 		if (mddev->sync_thread) {
4271 			set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4272 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4273 			md_unregister_thread(mddev->sync_thread);
4274 			mddev->sync_thread = NULL;
4275 		}
4276 
4277 		del_timer_sync(&mddev->safemode_timer);
4278 
4279 		switch(mode) {
4280 		case 1: /* readonly */
4281 			err  = -ENXIO;
4282 			if (mddev->ro==1)
4283 				goto out;
4284 			mddev->ro = 1;
4285 			break;
4286 		case 0: /* disassemble */
4287 		case 2: /* stop */
4288 			bitmap_flush(mddev);
4289 			md_super_wait(mddev);
4290 			if (mddev->ro)
4291 				set_disk_ro(disk, 0);
4292 
4293 			mddev->pers->stop(mddev);
4294 			mddev->queue->merge_bvec_fn = NULL;
4295 			mddev->queue->unplug_fn = NULL;
4296 			mddev->queue->backing_dev_info.congested_fn = NULL;
4297 			module_put(mddev->pers->owner);
4298 			if (mddev->pers->sync_request)
4299 				mddev->private = &md_redundancy_group;
4300 			mddev->pers = NULL;
4301 			/* tell userspace to handle 'inactive' */
4302 			sysfs_notify_dirent(mddev->sysfs_state);
4303 
4304 			list_for_each_entry(rdev, &mddev->disks, same_set)
4305 				if (rdev->raid_disk >= 0) {
4306 					char nm[20];
4307 					sprintf(nm, "rd%d", rdev->raid_disk);
4308 					sysfs_remove_link(&mddev->kobj, nm);
4309 				}
4310 
4311 			set_capacity(disk, 0);
4312 			mddev->changed = 1;
4313 
4314 			if (mddev->ro)
4315 				mddev->ro = 0;
4316 		}
4317 		if (!mddev->in_sync || mddev->flags) {
4318 			/* mark array as shutdown cleanly */
4319 			mddev->in_sync = 1;
4320 			md_update_sb(mddev, 1);
4321 		}
4322 		if (mode == 1)
4323 			set_disk_ro(disk, 1);
4324 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4325 	}
4326 
4327 	/*
4328 	 * Free resources if final stop
4329 	 */
4330 	if (mode == 0) {
4331 
4332 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4333 
4334 		bitmap_destroy(mddev);
4335 		if (mddev->bitmap_file) {
4336 			restore_bitmap_write_access(mddev->bitmap_file);
4337 			fput(mddev->bitmap_file);
4338 			mddev->bitmap_file = NULL;
4339 		}
4340 		mddev->bitmap_offset = 0;
4341 
4342 		/* make sure all md_delayed_delete calls have finished */
4343 		flush_scheduled_work();
4344 
4345 		export_array(mddev);
4346 
4347 		mddev->array_sectors = 0;
4348 		mddev->external_size = 0;
4349 		mddev->dev_sectors = 0;
4350 		mddev->raid_disks = 0;
4351 		mddev->recovery_cp = 0;
4352 		mddev->resync_min = 0;
4353 		mddev->resync_max = MaxSector;
4354 		mddev->reshape_position = MaxSector;
4355 		mddev->external = 0;
4356 		mddev->persistent = 0;
4357 		mddev->level = LEVEL_NONE;
4358 		mddev->clevel[0] = 0;
4359 		mddev->flags = 0;
4360 		mddev->ro = 0;
4361 		mddev->metadata_type[0] = 0;
4362 		mddev->chunk_sectors = 0;
4363 		mddev->ctime = mddev->utime = 0;
4364 		mddev->layout = 0;
4365 		mddev->max_disks = 0;
4366 		mddev->events = 0;
4367 		mddev->delta_disks = 0;
4368 		mddev->new_level = LEVEL_NONE;
4369 		mddev->new_layout = 0;
4370 		mddev->new_chunk_sectors = 0;
4371 		mddev->curr_resync = 0;
4372 		mddev->resync_mismatches = 0;
4373 		mddev->suspend_lo = mddev->suspend_hi = 0;
4374 		mddev->sync_speed_min = mddev->sync_speed_max = 0;
4375 		mddev->recovery = 0;
4376 		mddev->in_sync = 0;
4377 		mddev->changed = 0;
4378 		mddev->degraded = 0;
4379 		mddev->barriers_work = 0;
4380 		mddev->safemode = 0;
4381 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4382 		if (mddev->hold_active == UNTIL_STOP)
4383 			mddev->hold_active = 0;
4384 
4385 	} else if (mddev->pers)
4386 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
4387 			mdname(mddev));
4388 	err = 0;
4389 	blk_integrity_unregister(disk);
4390 	md_new_event(mddev);
4391 	sysfs_notify_dirent(mddev->sysfs_state);
4392 out:
4393 	return err;
4394 }
4395 
4396 #ifndef MODULE
4397 static void autorun_array(mddev_t *mddev)
4398 {
4399 	mdk_rdev_t *rdev;
4400 	int err;
4401 
4402 	if (list_empty(&mddev->disks))
4403 		return;
4404 
4405 	printk(KERN_INFO "md: running: ");
4406 
4407 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4408 		char b[BDEVNAME_SIZE];
4409 		printk("<%s>", bdevname(rdev->bdev,b));
4410 	}
4411 	printk("\n");
4412 
4413 	err = do_md_run(mddev);
4414 	if (err) {
4415 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4416 		do_md_stop(mddev, 0, 0);
4417 	}
4418 }
4419 
4420 /*
4421  * lets try to run arrays based on all disks that have arrived
4422  * until now. (those are in pending_raid_disks)
4423  *
4424  * the method: pick the first pending disk, collect all disks with
4425  * the same UUID, remove all from the pending list and put them into
4426  * the 'same_array' list. Then order this list based on superblock
4427  * update time (freshest comes first), kick out 'old' disks and
4428  * compare superblocks. If everything's fine then run it.
4429  *
4430  * If "unit" is allocated, then bump its reference count
4431  */
4432 static void autorun_devices(int part)
4433 {
4434 	mdk_rdev_t *rdev0, *rdev, *tmp;
4435 	mddev_t *mddev;
4436 	char b[BDEVNAME_SIZE];
4437 
4438 	printk(KERN_INFO "md: autorun ...\n");
4439 	while (!list_empty(&pending_raid_disks)) {
4440 		int unit;
4441 		dev_t dev;
4442 		LIST_HEAD(candidates);
4443 		rdev0 = list_entry(pending_raid_disks.next,
4444 					 mdk_rdev_t, same_set);
4445 
4446 		printk(KERN_INFO "md: considering %s ...\n",
4447 			bdevname(rdev0->bdev,b));
4448 		INIT_LIST_HEAD(&candidates);
4449 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4450 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4451 				printk(KERN_INFO "md:  adding %s ...\n",
4452 					bdevname(rdev->bdev,b));
4453 				list_move(&rdev->same_set, &candidates);
4454 			}
4455 		/*
4456 		 * now we have a set of devices, with all of them having
4457 		 * mostly sane superblocks. It's time to allocate the
4458 		 * mddev.
4459 		 */
4460 		if (part) {
4461 			dev = MKDEV(mdp_major,
4462 				    rdev0->preferred_minor << MdpMinorShift);
4463 			unit = MINOR(dev) >> MdpMinorShift;
4464 		} else {
4465 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4466 			unit = MINOR(dev);
4467 		}
4468 		if (rdev0->preferred_minor != unit) {
4469 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4470 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4471 			break;
4472 		}
4473 
4474 		md_probe(dev, NULL, NULL);
4475 		mddev = mddev_find(dev);
4476 		if (!mddev || !mddev->gendisk) {
4477 			if (mddev)
4478 				mddev_put(mddev);
4479 			printk(KERN_ERR
4480 				"md: cannot allocate memory for md drive.\n");
4481 			break;
4482 		}
4483 		if (mddev_lock(mddev))
4484 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4485 			       mdname(mddev));
4486 		else if (mddev->raid_disks || mddev->major_version
4487 			 || !list_empty(&mddev->disks)) {
4488 			printk(KERN_WARNING
4489 				"md: %s already running, cannot run %s\n",
4490 				mdname(mddev), bdevname(rdev0->bdev,b));
4491 			mddev_unlock(mddev);
4492 		} else {
4493 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4494 			mddev->persistent = 1;
4495 			rdev_for_each_list(rdev, tmp, &candidates) {
4496 				list_del_init(&rdev->same_set);
4497 				if (bind_rdev_to_array(rdev, mddev))
4498 					export_rdev(rdev);
4499 			}
4500 			autorun_array(mddev);
4501 			mddev_unlock(mddev);
4502 		}
4503 		/* on success, candidates will be empty, on error
4504 		 * it won't...
4505 		 */
4506 		rdev_for_each_list(rdev, tmp, &candidates) {
4507 			list_del_init(&rdev->same_set);
4508 			export_rdev(rdev);
4509 		}
4510 		mddev_put(mddev);
4511 	}
4512 	printk(KERN_INFO "md: ... autorun DONE.\n");
4513 }
4514 #endif /* !MODULE */
4515 
4516 static int get_version(void __user * arg)
4517 {
4518 	mdu_version_t ver;
4519 
4520 	ver.major = MD_MAJOR_VERSION;
4521 	ver.minor = MD_MINOR_VERSION;
4522 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4523 
4524 	if (copy_to_user(arg, &ver, sizeof(ver)))
4525 		return -EFAULT;
4526 
4527 	return 0;
4528 }
4529 
4530 static int get_array_info(mddev_t * mddev, void __user * arg)
4531 {
4532 	mdu_array_info_t info;
4533 	int nr,working,active,failed,spare;
4534 	mdk_rdev_t *rdev;
4535 
4536 	nr=working=active=failed=spare=0;
4537 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4538 		nr++;
4539 		if (test_bit(Faulty, &rdev->flags))
4540 			failed++;
4541 		else {
4542 			working++;
4543 			if (test_bit(In_sync, &rdev->flags))
4544 				active++;
4545 			else
4546 				spare++;
4547 		}
4548 	}
4549 
4550 	info.major_version = mddev->major_version;
4551 	info.minor_version = mddev->minor_version;
4552 	info.patch_version = MD_PATCHLEVEL_VERSION;
4553 	info.ctime         = mddev->ctime;
4554 	info.level         = mddev->level;
4555 	info.size          = mddev->dev_sectors / 2;
4556 	if (info.size != mddev->dev_sectors / 2) /* overflow */
4557 		info.size = -1;
4558 	info.nr_disks      = nr;
4559 	info.raid_disks    = mddev->raid_disks;
4560 	info.md_minor      = mddev->md_minor;
4561 	info.not_persistent= !mddev->persistent;
4562 
4563 	info.utime         = mddev->utime;
4564 	info.state         = 0;
4565 	if (mddev->in_sync)
4566 		info.state = (1<<MD_SB_CLEAN);
4567 	if (mddev->bitmap && mddev->bitmap_offset)
4568 		info.state = (1<<MD_SB_BITMAP_PRESENT);
4569 	info.active_disks  = active;
4570 	info.working_disks = working;
4571 	info.failed_disks  = failed;
4572 	info.spare_disks   = spare;
4573 
4574 	info.layout        = mddev->layout;
4575 	info.chunk_size    = mddev->chunk_sectors << 9;
4576 
4577 	if (copy_to_user(arg, &info, sizeof(info)))
4578 		return -EFAULT;
4579 
4580 	return 0;
4581 }
4582 
4583 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
4584 {
4585 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
4586 	char *ptr, *buf = NULL;
4587 	int err = -ENOMEM;
4588 
4589 	if (md_allow_write(mddev))
4590 		file = kmalloc(sizeof(*file), GFP_NOIO);
4591 	else
4592 		file = kmalloc(sizeof(*file), GFP_KERNEL);
4593 
4594 	if (!file)
4595 		goto out;
4596 
4597 	/* bitmap disabled, zero the first byte and copy out */
4598 	if (!mddev->bitmap || !mddev->bitmap->file) {
4599 		file->pathname[0] = '\0';
4600 		goto copy_out;
4601 	}
4602 
4603 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
4604 	if (!buf)
4605 		goto out;
4606 
4607 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
4608 	if (IS_ERR(ptr))
4609 		goto out;
4610 
4611 	strcpy(file->pathname, ptr);
4612 
4613 copy_out:
4614 	err = 0;
4615 	if (copy_to_user(arg, file, sizeof(*file)))
4616 		err = -EFAULT;
4617 out:
4618 	kfree(buf);
4619 	kfree(file);
4620 	return err;
4621 }
4622 
4623 static int get_disk_info(mddev_t * mddev, void __user * arg)
4624 {
4625 	mdu_disk_info_t info;
4626 	mdk_rdev_t *rdev;
4627 
4628 	if (copy_from_user(&info, arg, sizeof(info)))
4629 		return -EFAULT;
4630 
4631 	rdev = find_rdev_nr(mddev, info.number);
4632 	if (rdev) {
4633 		info.major = MAJOR(rdev->bdev->bd_dev);
4634 		info.minor = MINOR(rdev->bdev->bd_dev);
4635 		info.raid_disk = rdev->raid_disk;
4636 		info.state = 0;
4637 		if (test_bit(Faulty, &rdev->flags))
4638 			info.state |= (1<<MD_DISK_FAULTY);
4639 		else if (test_bit(In_sync, &rdev->flags)) {
4640 			info.state |= (1<<MD_DISK_ACTIVE);
4641 			info.state |= (1<<MD_DISK_SYNC);
4642 		}
4643 		if (test_bit(WriteMostly, &rdev->flags))
4644 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
4645 	} else {
4646 		info.major = info.minor = 0;
4647 		info.raid_disk = -1;
4648 		info.state = (1<<MD_DISK_REMOVED);
4649 	}
4650 
4651 	if (copy_to_user(arg, &info, sizeof(info)))
4652 		return -EFAULT;
4653 
4654 	return 0;
4655 }
4656 
4657 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
4658 {
4659 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4660 	mdk_rdev_t *rdev;
4661 	dev_t dev = MKDEV(info->major,info->minor);
4662 
4663 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
4664 		return -EOVERFLOW;
4665 
4666 	if (!mddev->raid_disks) {
4667 		int err;
4668 		/* expecting a device which has a superblock */
4669 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
4670 		if (IS_ERR(rdev)) {
4671 			printk(KERN_WARNING
4672 				"md: md_import_device returned %ld\n",
4673 				PTR_ERR(rdev));
4674 			return PTR_ERR(rdev);
4675 		}
4676 		if (!list_empty(&mddev->disks)) {
4677 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
4678 							mdk_rdev_t, same_set);
4679 			int err = super_types[mddev->major_version]
4680 				.load_super(rdev, rdev0, mddev->minor_version);
4681 			if (err < 0) {
4682 				printk(KERN_WARNING
4683 					"md: %s has different UUID to %s\n",
4684 					bdevname(rdev->bdev,b),
4685 					bdevname(rdev0->bdev,b2));
4686 				export_rdev(rdev);
4687 				return -EINVAL;
4688 			}
4689 		}
4690 		err = bind_rdev_to_array(rdev, mddev);
4691 		if (err)
4692 			export_rdev(rdev);
4693 		return err;
4694 	}
4695 
4696 	/*
4697 	 * add_new_disk can be used once the array is assembled
4698 	 * to add "hot spares".  They must already have a superblock
4699 	 * written
4700 	 */
4701 	if (mddev->pers) {
4702 		int err;
4703 		if (!mddev->pers->hot_add_disk) {
4704 			printk(KERN_WARNING
4705 				"%s: personality does not support diskops!\n",
4706 			       mdname(mddev));
4707 			return -EINVAL;
4708 		}
4709 		if (mddev->persistent)
4710 			rdev = md_import_device(dev, mddev->major_version,
4711 						mddev->minor_version);
4712 		else
4713 			rdev = md_import_device(dev, -1, -1);
4714 		if (IS_ERR(rdev)) {
4715 			printk(KERN_WARNING
4716 				"md: md_import_device returned %ld\n",
4717 				PTR_ERR(rdev));
4718 			return PTR_ERR(rdev);
4719 		}
4720 		/* set save_raid_disk if appropriate */
4721 		if (!mddev->persistent) {
4722 			if (info->state & (1<<MD_DISK_SYNC)  &&
4723 			    info->raid_disk < mddev->raid_disks)
4724 				rdev->raid_disk = info->raid_disk;
4725 			else
4726 				rdev->raid_disk = -1;
4727 		} else
4728 			super_types[mddev->major_version].
4729 				validate_super(mddev, rdev);
4730 		rdev->saved_raid_disk = rdev->raid_disk;
4731 
4732 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
4733 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4734 			set_bit(WriteMostly, &rdev->flags);
4735 		else
4736 			clear_bit(WriteMostly, &rdev->flags);
4737 
4738 		rdev->raid_disk = -1;
4739 		err = bind_rdev_to_array(rdev, mddev);
4740 		if (!err && !mddev->pers->hot_remove_disk) {
4741 			/* If there is hot_add_disk but no hot_remove_disk
4742 			 * then added disks for geometry changes,
4743 			 * and should be added immediately.
4744 			 */
4745 			super_types[mddev->major_version].
4746 				validate_super(mddev, rdev);
4747 			err = mddev->pers->hot_add_disk(mddev, rdev);
4748 			if (err)
4749 				unbind_rdev_from_array(rdev);
4750 		}
4751 		if (err)
4752 			export_rdev(rdev);
4753 		else
4754 			sysfs_notify_dirent(rdev->sysfs_state);
4755 
4756 		md_update_sb(mddev, 1);
4757 		if (mddev->degraded)
4758 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4759 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4760 		md_wakeup_thread(mddev->thread);
4761 		return err;
4762 	}
4763 
4764 	/* otherwise, add_new_disk is only allowed
4765 	 * for major_version==0 superblocks
4766 	 */
4767 	if (mddev->major_version != 0) {
4768 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
4769 		       mdname(mddev));
4770 		return -EINVAL;
4771 	}
4772 
4773 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
4774 		int err;
4775 		rdev = md_import_device(dev, -1, 0);
4776 		if (IS_ERR(rdev)) {
4777 			printk(KERN_WARNING
4778 				"md: error, md_import_device() returned %ld\n",
4779 				PTR_ERR(rdev));
4780 			return PTR_ERR(rdev);
4781 		}
4782 		rdev->desc_nr = info->number;
4783 		if (info->raid_disk < mddev->raid_disks)
4784 			rdev->raid_disk = info->raid_disk;
4785 		else
4786 			rdev->raid_disk = -1;
4787 
4788 		if (rdev->raid_disk < mddev->raid_disks)
4789 			if (info->state & (1<<MD_DISK_SYNC))
4790 				set_bit(In_sync, &rdev->flags);
4791 
4792 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4793 			set_bit(WriteMostly, &rdev->flags);
4794 
4795 		if (!mddev->persistent) {
4796 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
4797 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4798 		} else
4799 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4800 		rdev->sectors = rdev->sb_start;
4801 
4802 		err = bind_rdev_to_array(rdev, mddev);
4803 		if (err) {
4804 			export_rdev(rdev);
4805 			return err;
4806 		}
4807 	}
4808 
4809 	return 0;
4810 }
4811 
4812 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
4813 {
4814 	char b[BDEVNAME_SIZE];
4815 	mdk_rdev_t *rdev;
4816 
4817 	rdev = find_rdev(mddev, dev);
4818 	if (!rdev)
4819 		return -ENXIO;
4820 
4821 	if (rdev->raid_disk >= 0)
4822 		goto busy;
4823 
4824 	kick_rdev_from_array(rdev);
4825 	md_update_sb(mddev, 1);
4826 	md_new_event(mddev);
4827 
4828 	return 0;
4829 busy:
4830 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
4831 		bdevname(rdev->bdev,b), mdname(mddev));
4832 	return -EBUSY;
4833 }
4834 
4835 static int hot_add_disk(mddev_t * mddev, dev_t dev)
4836 {
4837 	char b[BDEVNAME_SIZE];
4838 	int err;
4839 	mdk_rdev_t *rdev;
4840 
4841 	if (!mddev->pers)
4842 		return -ENODEV;
4843 
4844 	if (mddev->major_version != 0) {
4845 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
4846 			" version-0 superblocks.\n",
4847 			mdname(mddev));
4848 		return -EINVAL;
4849 	}
4850 	if (!mddev->pers->hot_add_disk) {
4851 		printk(KERN_WARNING
4852 			"%s: personality does not support diskops!\n",
4853 			mdname(mddev));
4854 		return -EINVAL;
4855 	}
4856 
4857 	rdev = md_import_device(dev, -1, 0);
4858 	if (IS_ERR(rdev)) {
4859 		printk(KERN_WARNING
4860 			"md: error, md_import_device() returned %ld\n",
4861 			PTR_ERR(rdev));
4862 		return -EINVAL;
4863 	}
4864 
4865 	if (mddev->persistent)
4866 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4867 	else
4868 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4869 
4870 	rdev->sectors = rdev->sb_start;
4871 
4872 	if (test_bit(Faulty, &rdev->flags)) {
4873 		printk(KERN_WARNING
4874 			"md: can not hot-add faulty %s disk to %s!\n",
4875 			bdevname(rdev->bdev,b), mdname(mddev));
4876 		err = -EINVAL;
4877 		goto abort_export;
4878 	}
4879 	clear_bit(In_sync, &rdev->flags);
4880 	rdev->desc_nr = -1;
4881 	rdev->saved_raid_disk = -1;
4882 	err = bind_rdev_to_array(rdev, mddev);
4883 	if (err)
4884 		goto abort_export;
4885 
4886 	/*
4887 	 * The rest should better be atomic, we can have disk failures
4888 	 * noticed in interrupt contexts ...
4889 	 */
4890 
4891 	rdev->raid_disk = -1;
4892 
4893 	md_update_sb(mddev, 1);
4894 
4895 	/*
4896 	 * Kick recovery, maybe this spare has to be added to the
4897 	 * array immediately.
4898 	 */
4899 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4900 	md_wakeup_thread(mddev->thread);
4901 	md_new_event(mddev);
4902 	return 0;
4903 
4904 abort_export:
4905 	export_rdev(rdev);
4906 	return err;
4907 }
4908 
4909 static int set_bitmap_file(mddev_t *mddev, int fd)
4910 {
4911 	int err;
4912 
4913 	if (mddev->pers) {
4914 		if (!mddev->pers->quiesce)
4915 			return -EBUSY;
4916 		if (mddev->recovery || mddev->sync_thread)
4917 			return -EBUSY;
4918 		/* we should be able to change the bitmap.. */
4919 	}
4920 
4921 
4922 	if (fd >= 0) {
4923 		if (mddev->bitmap)
4924 			return -EEXIST; /* cannot add when bitmap is present */
4925 		mddev->bitmap_file = fget(fd);
4926 
4927 		if (mddev->bitmap_file == NULL) {
4928 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
4929 			       mdname(mddev));
4930 			return -EBADF;
4931 		}
4932 
4933 		err = deny_bitmap_write_access(mddev->bitmap_file);
4934 		if (err) {
4935 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
4936 			       mdname(mddev));
4937 			fput(mddev->bitmap_file);
4938 			mddev->bitmap_file = NULL;
4939 			return err;
4940 		}
4941 		mddev->bitmap_offset = 0; /* file overrides offset */
4942 	} else if (mddev->bitmap == NULL)
4943 		return -ENOENT; /* cannot remove what isn't there */
4944 	err = 0;
4945 	if (mddev->pers) {
4946 		mddev->pers->quiesce(mddev, 1);
4947 		if (fd >= 0)
4948 			err = bitmap_create(mddev);
4949 		if (fd < 0 || err) {
4950 			bitmap_destroy(mddev);
4951 			fd = -1; /* make sure to put the file */
4952 		}
4953 		mddev->pers->quiesce(mddev, 0);
4954 	}
4955 	if (fd < 0) {
4956 		if (mddev->bitmap_file) {
4957 			restore_bitmap_write_access(mddev->bitmap_file);
4958 			fput(mddev->bitmap_file);
4959 		}
4960 		mddev->bitmap_file = NULL;
4961 	}
4962 
4963 	return err;
4964 }
4965 
4966 /*
4967  * set_array_info is used two different ways
4968  * The original usage is when creating a new array.
4969  * In this usage, raid_disks is > 0 and it together with
4970  *  level, size, not_persistent,layout,chunksize determine the
4971  *  shape of the array.
4972  *  This will always create an array with a type-0.90.0 superblock.
4973  * The newer usage is when assembling an array.
4974  *  In this case raid_disks will be 0, and the major_version field is
4975  *  use to determine which style super-blocks are to be found on the devices.
4976  *  The minor and patch _version numbers are also kept incase the
4977  *  super_block handler wishes to interpret them.
4978  */
4979 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
4980 {
4981 
4982 	if (info->raid_disks == 0) {
4983 		/* just setting version number for superblock loading */
4984 		if (info->major_version < 0 ||
4985 		    info->major_version >= ARRAY_SIZE(super_types) ||
4986 		    super_types[info->major_version].name == NULL) {
4987 			/* maybe try to auto-load a module? */
4988 			printk(KERN_INFO
4989 				"md: superblock version %d not known\n",
4990 				info->major_version);
4991 			return -EINVAL;
4992 		}
4993 		mddev->major_version = info->major_version;
4994 		mddev->minor_version = info->minor_version;
4995 		mddev->patch_version = info->patch_version;
4996 		mddev->persistent = !info->not_persistent;
4997 		return 0;
4998 	}
4999 	mddev->major_version = MD_MAJOR_VERSION;
5000 	mddev->minor_version = MD_MINOR_VERSION;
5001 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5002 	mddev->ctime         = get_seconds();
5003 
5004 	mddev->level         = info->level;
5005 	mddev->clevel[0]     = 0;
5006 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5007 	mddev->raid_disks    = info->raid_disks;
5008 	/* don't set md_minor, it is determined by which /dev/md* was
5009 	 * openned
5010 	 */
5011 	if (info->state & (1<<MD_SB_CLEAN))
5012 		mddev->recovery_cp = MaxSector;
5013 	else
5014 		mddev->recovery_cp = 0;
5015 	mddev->persistent    = ! info->not_persistent;
5016 	mddev->external	     = 0;
5017 
5018 	mddev->layout        = info->layout;
5019 	mddev->chunk_sectors = info->chunk_size >> 9;
5020 
5021 	mddev->max_disks     = MD_SB_DISKS;
5022 
5023 	if (mddev->persistent)
5024 		mddev->flags         = 0;
5025 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5026 
5027 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
5028 	mddev->bitmap_offset = 0;
5029 
5030 	mddev->reshape_position = MaxSector;
5031 
5032 	/*
5033 	 * Generate a 128 bit UUID
5034 	 */
5035 	get_random_bytes(mddev->uuid, 16);
5036 
5037 	mddev->new_level = mddev->level;
5038 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5039 	mddev->new_layout = mddev->layout;
5040 	mddev->delta_disks = 0;
5041 
5042 	return 0;
5043 }
5044 
5045 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5046 {
5047 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5048 
5049 	if (mddev->external_size)
5050 		return;
5051 
5052 	mddev->array_sectors = array_sectors;
5053 }
5054 EXPORT_SYMBOL(md_set_array_sectors);
5055 
5056 static int update_size(mddev_t *mddev, sector_t num_sectors)
5057 {
5058 	mdk_rdev_t *rdev;
5059 	int rv;
5060 	int fit = (num_sectors == 0);
5061 
5062 	if (mddev->pers->resize == NULL)
5063 		return -EINVAL;
5064 	/* The "num_sectors" is the number of sectors of each device that
5065 	 * is used.  This can only make sense for arrays with redundancy.
5066 	 * linear and raid0 always use whatever space is available. We can only
5067 	 * consider changing this number if no resync or reconstruction is
5068 	 * happening, and if the new size is acceptable. It must fit before the
5069 	 * sb_start or, if that is <data_offset, it must fit before the size
5070 	 * of each device.  If num_sectors is zero, we find the largest size
5071 	 * that fits.
5072 
5073 	 */
5074 	if (mddev->sync_thread)
5075 		return -EBUSY;
5076 	if (mddev->bitmap)
5077 		/* Sorry, cannot grow a bitmap yet, just remove it,
5078 		 * grow, and re-add.
5079 		 */
5080 		return -EBUSY;
5081 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5082 		sector_t avail = rdev->sectors;
5083 
5084 		if (fit && (num_sectors == 0 || num_sectors > avail))
5085 			num_sectors = avail;
5086 		if (avail < num_sectors)
5087 			return -ENOSPC;
5088 	}
5089 	rv = mddev->pers->resize(mddev, num_sectors);
5090 	if (!rv) {
5091 		struct block_device *bdev;
5092 
5093 		bdev = bdget_disk(mddev->gendisk, 0);
5094 		if (bdev) {
5095 			mutex_lock(&bdev->bd_inode->i_mutex);
5096 			i_size_write(bdev->bd_inode,
5097 				     (loff_t)mddev->array_sectors << 9);
5098 			mutex_unlock(&bdev->bd_inode->i_mutex);
5099 			bdput(bdev);
5100 		}
5101 	}
5102 	return rv;
5103 }
5104 
5105 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5106 {
5107 	int rv;
5108 	/* change the number of raid disks */
5109 	if (mddev->pers->check_reshape == NULL)
5110 		return -EINVAL;
5111 	if (raid_disks <= 0 ||
5112 	    raid_disks >= mddev->max_disks)
5113 		return -EINVAL;
5114 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5115 		return -EBUSY;
5116 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5117 
5118 	rv = mddev->pers->check_reshape(mddev);
5119 	return rv;
5120 }
5121 
5122 
5123 /*
5124  * update_array_info is used to change the configuration of an
5125  * on-line array.
5126  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5127  * fields in the info are checked against the array.
5128  * Any differences that cannot be handled will cause an error.
5129  * Normally, only one change can be managed at a time.
5130  */
5131 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5132 {
5133 	int rv = 0;
5134 	int cnt = 0;
5135 	int state = 0;
5136 
5137 	/* calculate expected state,ignoring low bits */
5138 	if (mddev->bitmap && mddev->bitmap_offset)
5139 		state |= (1 << MD_SB_BITMAP_PRESENT);
5140 
5141 	if (mddev->major_version != info->major_version ||
5142 	    mddev->minor_version != info->minor_version ||
5143 /*	    mddev->patch_version != info->patch_version || */
5144 	    mddev->ctime         != info->ctime         ||
5145 	    mddev->level         != info->level         ||
5146 /*	    mddev->layout        != info->layout        || */
5147 	    !mddev->persistent	 != info->not_persistent||
5148 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5149 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5150 	    ((state^info->state) & 0xfffffe00)
5151 		)
5152 		return -EINVAL;
5153 	/* Check there is only one change */
5154 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5155 		cnt++;
5156 	if (mddev->raid_disks != info->raid_disks)
5157 		cnt++;
5158 	if (mddev->layout != info->layout)
5159 		cnt++;
5160 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5161 		cnt++;
5162 	if (cnt == 0)
5163 		return 0;
5164 	if (cnt > 1)
5165 		return -EINVAL;
5166 
5167 	if (mddev->layout != info->layout) {
5168 		/* Change layout
5169 		 * we don't need to do anything at the md level, the
5170 		 * personality will take care of it all.
5171 		 */
5172 		if (mddev->pers->check_reshape == NULL)
5173 			return -EINVAL;
5174 		else {
5175 			mddev->new_layout = info->layout;
5176 			rv = mddev->pers->check_reshape(mddev);
5177 			if (rv)
5178 				mddev->new_layout = mddev->layout;
5179 			return rv;
5180 		}
5181 	}
5182 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5183 		rv = update_size(mddev, (sector_t)info->size * 2);
5184 
5185 	if (mddev->raid_disks    != info->raid_disks)
5186 		rv = update_raid_disks(mddev, info->raid_disks);
5187 
5188 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5189 		if (mddev->pers->quiesce == NULL)
5190 			return -EINVAL;
5191 		if (mddev->recovery || mddev->sync_thread)
5192 			return -EBUSY;
5193 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5194 			/* add the bitmap */
5195 			if (mddev->bitmap)
5196 				return -EEXIST;
5197 			if (mddev->default_bitmap_offset == 0)
5198 				return -EINVAL;
5199 			mddev->bitmap_offset = mddev->default_bitmap_offset;
5200 			mddev->pers->quiesce(mddev, 1);
5201 			rv = bitmap_create(mddev);
5202 			if (rv)
5203 				bitmap_destroy(mddev);
5204 			mddev->pers->quiesce(mddev, 0);
5205 		} else {
5206 			/* remove the bitmap */
5207 			if (!mddev->bitmap)
5208 				return -ENOENT;
5209 			if (mddev->bitmap->file)
5210 				return -EINVAL;
5211 			mddev->pers->quiesce(mddev, 1);
5212 			bitmap_destroy(mddev);
5213 			mddev->pers->quiesce(mddev, 0);
5214 			mddev->bitmap_offset = 0;
5215 		}
5216 	}
5217 	md_update_sb(mddev, 1);
5218 	return rv;
5219 }
5220 
5221 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5222 {
5223 	mdk_rdev_t *rdev;
5224 
5225 	if (mddev->pers == NULL)
5226 		return -ENODEV;
5227 
5228 	rdev = find_rdev(mddev, dev);
5229 	if (!rdev)
5230 		return -ENODEV;
5231 
5232 	md_error(mddev, rdev);
5233 	return 0;
5234 }
5235 
5236 /*
5237  * We have a problem here : there is no easy way to give a CHS
5238  * virtual geometry. We currently pretend that we have a 2 heads
5239  * 4 sectors (with a BIG number of cylinders...). This drives
5240  * dosfs just mad... ;-)
5241  */
5242 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5243 {
5244 	mddev_t *mddev = bdev->bd_disk->private_data;
5245 
5246 	geo->heads = 2;
5247 	geo->sectors = 4;
5248 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
5249 	return 0;
5250 }
5251 
5252 static int md_ioctl(struct block_device *bdev, fmode_t mode,
5253 			unsigned int cmd, unsigned long arg)
5254 {
5255 	int err = 0;
5256 	void __user *argp = (void __user *)arg;
5257 	mddev_t *mddev = NULL;
5258 
5259 	if (!capable(CAP_SYS_ADMIN))
5260 		return -EACCES;
5261 
5262 	/*
5263 	 * Commands dealing with the RAID driver but not any
5264 	 * particular array:
5265 	 */
5266 	switch (cmd)
5267 	{
5268 		case RAID_VERSION:
5269 			err = get_version(argp);
5270 			goto done;
5271 
5272 		case PRINT_RAID_DEBUG:
5273 			err = 0;
5274 			md_print_devices();
5275 			goto done;
5276 
5277 #ifndef MODULE
5278 		case RAID_AUTORUN:
5279 			err = 0;
5280 			autostart_arrays(arg);
5281 			goto done;
5282 #endif
5283 		default:;
5284 	}
5285 
5286 	/*
5287 	 * Commands creating/starting a new array:
5288 	 */
5289 
5290 	mddev = bdev->bd_disk->private_data;
5291 
5292 	if (!mddev) {
5293 		BUG();
5294 		goto abort;
5295 	}
5296 
5297 	err = mddev_lock(mddev);
5298 	if (err) {
5299 		printk(KERN_INFO
5300 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5301 			err, cmd);
5302 		goto abort;
5303 	}
5304 
5305 	switch (cmd)
5306 	{
5307 		case SET_ARRAY_INFO:
5308 			{
5309 				mdu_array_info_t info;
5310 				if (!arg)
5311 					memset(&info, 0, sizeof(info));
5312 				else if (copy_from_user(&info, argp, sizeof(info))) {
5313 					err = -EFAULT;
5314 					goto abort_unlock;
5315 				}
5316 				if (mddev->pers) {
5317 					err = update_array_info(mddev, &info);
5318 					if (err) {
5319 						printk(KERN_WARNING "md: couldn't update"
5320 						       " array info. %d\n", err);
5321 						goto abort_unlock;
5322 					}
5323 					goto done_unlock;
5324 				}
5325 				if (!list_empty(&mddev->disks)) {
5326 					printk(KERN_WARNING
5327 					       "md: array %s already has disks!\n",
5328 					       mdname(mddev));
5329 					err = -EBUSY;
5330 					goto abort_unlock;
5331 				}
5332 				if (mddev->raid_disks) {
5333 					printk(KERN_WARNING
5334 					       "md: array %s already initialised!\n",
5335 					       mdname(mddev));
5336 					err = -EBUSY;
5337 					goto abort_unlock;
5338 				}
5339 				err = set_array_info(mddev, &info);
5340 				if (err) {
5341 					printk(KERN_WARNING "md: couldn't set"
5342 					       " array info. %d\n", err);
5343 					goto abort_unlock;
5344 				}
5345 			}
5346 			goto done_unlock;
5347 
5348 		default:;
5349 	}
5350 
5351 	/*
5352 	 * Commands querying/configuring an existing array:
5353 	 */
5354 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5355 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5356 	if ((!mddev->raid_disks && !mddev->external)
5357 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5358 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5359 	    && cmd != GET_BITMAP_FILE) {
5360 		err = -ENODEV;
5361 		goto abort_unlock;
5362 	}
5363 
5364 	/*
5365 	 * Commands even a read-only array can execute:
5366 	 */
5367 	switch (cmd)
5368 	{
5369 		case GET_ARRAY_INFO:
5370 			err = get_array_info(mddev, argp);
5371 			goto done_unlock;
5372 
5373 		case GET_BITMAP_FILE:
5374 			err = get_bitmap_file(mddev, argp);
5375 			goto done_unlock;
5376 
5377 		case GET_DISK_INFO:
5378 			err = get_disk_info(mddev, argp);
5379 			goto done_unlock;
5380 
5381 		case RESTART_ARRAY_RW:
5382 			err = restart_array(mddev);
5383 			goto done_unlock;
5384 
5385 		case STOP_ARRAY:
5386 			err = do_md_stop(mddev, 0, 1);
5387 			goto done_unlock;
5388 
5389 		case STOP_ARRAY_RO:
5390 			err = do_md_stop(mddev, 1, 1);
5391 			goto done_unlock;
5392 
5393 	}
5394 
5395 	/*
5396 	 * The remaining ioctls are changing the state of the
5397 	 * superblock, so we do not allow them on read-only arrays.
5398 	 * However non-MD ioctls (e.g. get-size) will still come through
5399 	 * here and hit the 'default' below, so only disallow
5400 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5401 	 */
5402 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5403 		if (mddev->ro == 2) {
5404 			mddev->ro = 0;
5405 			sysfs_notify_dirent(mddev->sysfs_state);
5406 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5407 			md_wakeup_thread(mddev->thread);
5408 		} else {
5409 			err = -EROFS;
5410 			goto abort_unlock;
5411 		}
5412 	}
5413 
5414 	switch (cmd)
5415 	{
5416 		case ADD_NEW_DISK:
5417 		{
5418 			mdu_disk_info_t info;
5419 			if (copy_from_user(&info, argp, sizeof(info)))
5420 				err = -EFAULT;
5421 			else
5422 				err = add_new_disk(mddev, &info);
5423 			goto done_unlock;
5424 		}
5425 
5426 		case HOT_REMOVE_DISK:
5427 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5428 			goto done_unlock;
5429 
5430 		case HOT_ADD_DISK:
5431 			err = hot_add_disk(mddev, new_decode_dev(arg));
5432 			goto done_unlock;
5433 
5434 		case SET_DISK_FAULTY:
5435 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5436 			goto done_unlock;
5437 
5438 		case RUN_ARRAY:
5439 			err = do_md_run(mddev);
5440 			goto done_unlock;
5441 
5442 		case SET_BITMAP_FILE:
5443 			err = set_bitmap_file(mddev, (int)arg);
5444 			goto done_unlock;
5445 
5446 		default:
5447 			err = -EINVAL;
5448 			goto abort_unlock;
5449 	}
5450 
5451 done_unlock:
5452 abort_unlock:
5453 	if (mddev->hold_active == UNTIL_IOCTL &&
5454 	    err != -EINVAL)
5455 		mddev->hold_active = 0;
5456 	mddev_unlock(mddev);
5457 
5458 	return err;
5459 done:
5460 	if (err)
5461 		MD_BUG();
5462 abort:
5463 	return err;
5464 }
5465 
5466 static int md_open(struct block_device *bdev, fmode_t mode)
5467 {
5468 	/*
5469 	 * Succeed if we can lock the mddev, which confirms that
5470 	 * it isn't being stopped right now.
5471 	 */
5472 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5473 	int err;
5474 
5475 	if (mddev->gendisk != bdev->bd_disk) {
5476 		/* we are racing with mddev_put which is discarding this
5477 		 * bd_disk.
5478 		 */
5479 		mddev_put(mddev);
5480 		/* Wait until bdev->bd_disk is definitely gone */
5481 		flush_scheduled_work();
5482 		/* Then retry the open from the top */
5483 		return -ERESTARTSYS;
5484 	}
5485 	BUG_ON(mddev != bdev->bd_disk->private_data);
5486 
5487 	if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
5488 		goto out;
5489 
5490 	err = 0;
5491 	atomic_inc(&mddev->openers);
5492 	mddev_unlock(mddev);
5493 
5494 	check_disk_change(bdev);
5495  out:
5496 	return err;
5497 }
5498 
5499 static int md_release(struct gendisk *disk, fmode_t mode)
5500 {
5501  	mddev_t *mddev = disk->private_data;
5502 
5503 	BUG_ON(!mddev);
5504 	atomic_dec(&mddev->openers);
5505 	mddev_put(mddev);
5506 
5507 	return 0;
5508 }
5509 
5510 static int md_media_changed(struct gendisk *disk)
5511 {
5512 	mddev_t *mddev = disk->private_data;
5513 
5514 	return mddev->changed;
5515 }
5516 
5517 static int md_revalidate(struct gendisk *disk)
5518 {
5519 	mddev_t *mddev = disk->private_data;
5520 
5521 	mddev->changed = 0;
5522 	return 0;
5523 }
5524 static struct block_device_operations md_fops =
5525 {
5526 	.owner		= THIS_MODULE,
5527 	.open		= md_open,
5528 	.release	= md_release,
5529 	.ioctl		= md_ioctl,
5530 	.getgeo		= md_getgeo,
5531 	.media_changed	= md_media_changed,
5532 	.revalidate_disk= md_revalidate,
5533 };
5534 
5535 static int md_thread(void * arg)
5536 {
5537 	mdk_thread_t *thread = arg;
5538 
5539 	/*
5540 	 * md_thread is a 'system-thread', it's priority should be very
5541 	 * high. We avoid resource deadlocks individually in each
5542 	 * raid personality. (RAID5 does preallocation) We also use RR and
5543 	 * the very same RT priority as kswapd, thus we will never get
5544 	 * into a priority inversion deadlock.
5545 	 *
5546 	 * we definitely have to have equal or higher priority than
5547 	 * bdflush, otherwise bdflush will deadlock if there are too
5548 	 * many dirty RAID5 blocks.
5549 	 */
5550 
5551 	allow_signal(SIGKILL);
5552 	while (!kthread_should_stop()) {
5553 
5554 		/* We need to wait INTERRUPTIBLE so that
5555 		 * we don't add to the load-average.
5556 		 * That means we need to be sure no signals are
5557 		 * pending
5558 		 */
5559 		if (signal_pending(current))
5560 			flush_signals(current);
5561 
5562 		wait_event_interruptible_timeout
5563 			(thread->wqueue,
5564 			 test_bit(THREAD_WAKEUP, &thread->flags)
5565 			 || kthread_should_stop(),
5566 			 thread->timeout);
5567 
5568 		clear_bit(THREAD_WAKEUP, &thread->flags);
5569 
5570 		thread->run(thread->mddev);
5571 	}
5572 
5573 	return 0;
5574 }
5575 
5576 void md_wakeup_thread(mdk_thread_t *thread)
5577 {
5578 	if (thread) {
5579 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
5580 		set_bit(THREAD_WAKEUP, &thread->flags);
5581 		wake_up(&thread->wqueue);
5582 	}
5583 }
5584 
5585 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
5586 				 const char *name)
5587 {
5588 	mdk_thread_t *thread;
5589 
5590 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
5591 	if (!thread)
5592 		return NULL;
5593 
5594 	init_waitqueue_head(&thread->wqueue);
5595 
5596 	thread->run = run;
5597 	thread->mddev = mddev;
5598 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
5599 	thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
5600 	if (IS_ERR(thread->tsk)) {
5601 		kfree(thread);
5602 		return NULL;
5603 	}
5604 	return thread;
5605 }
5606 
5607 void md_unregister_thread(mdk_thread_t *thread)
5608 {
5609 	if (!thread)
5610 		return;
5611 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
5612 
5613 	kthread_stop(thread->tsk);
5614 	kfree(thread);
5615 }
5616 
5617 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
5618 {
5619 	if (!mddev) {
5620 		MD_BUG();
5621 		return;
5622 	}
5623 
5624 	if (!rdev || test_bit(Faulty, &rdev->flags))
5625 		return;
5626 
5627 	if (mddev->external)
5628 		set_bit(Blocked, &rdev->flags);
5629 /*
5630 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
5631 		mdname(mddev),
5632 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
5633 		__builtin_return_address(0),__builtin_return_address(1),
5634 		__builtin_return_address(2),__builtin_return_address(3));
5635 */
5636 	if (!mddev->pers)
5637 		return;
5638 	if (!mddev->pers->error_handler)
5639 		return;
5640 	mddev->pers->error_handler(mddev,rdev);
5641 	if (mddev->degraded)
5642 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5643 	set_bit(StateChanged, &rdev->flags);
5644 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5645 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5646 	md_wakeup_thread(mddev->thread);
5647 	md_new_event_inintr(mddev);
5648 }
5649 
5650 /* seq_file implementation /proc/mdstat */
5651 
5652 static void status_unused(struct seq_file *seq)
5653 {
5654 	int i = 0;
5655 	mdk_rdev_t *rdev;
5656 
5657 	seq_printf(seq, "unused devices: ");
5658 
5659 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
5660 		char b[BDEVNAME_SIZE];
5661 		i++;
5662 		seq_printf(seq, "%s ",
5663 			      bdevname(rdev->bdev,b));
5664 	}
5665 	if (!i)
5666 		seq_printf(seq, "<none>");
5667 
5668 	seq_printf(seq, "\n");
5669 }
5670 
5671 
5672 static void status_resync(struct seq_file *seq, mddev_t * mddev)
5673 {
5674 	sector_t max_sectors, resync, res;
5675 	unsigned long dt, db;
5676 	sector_t rt;
5677 	int scale;
5678 	unsigned int per_milli;
5679 
5680 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
5681 
5682 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
5683 		max_sectors = mddev->resync_max_sectors;
5684 	else
5685 		max_sectors = mddev->dev_sectors;
5686 
5687 	/*
5688 	 * Should not happen.
5689 	 */
5690 	if (!max_sectors) {
5691 		MD_BUG();
5692 		return;
5693 	}
5694 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
5695 	 * in a sector_t, and (max_sectors>>scale) will fit in a
5696 	 * u32, as those are the requirements for sector_div.
5697 	 * Thus 'scale' must be at least 10
5698 	 */
5699 	scale = 10;
5700 	if (sizeof(sector_t) > sizeof(unsigned long)) {
5701 		while ( max_sectors/2 > (1ULL<<(scale+32)))
5702 			scale++;
5703 	}
5704 	res = (resync>>scale)*1000;
5705 	sector_div(res, (u32)((max_sectors>>scale)+1));
5706 
5707 	per_milli = res;
5708 	{
5709 		int i, x = per_milli/50, y = 20-x;
5710 		seq_printf(seq, "[");
5711 		for (i = 0; i < x; i++)
5712 			seq_printf(seq, "=");
5713 		seq_printf(seq, ">");
5714 		for (i = 0; i < y; i++)
5715 			seq_printf(seq, ".");
5716 		seq_printf(seq, "] ");
5717 	}
5718 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
5719 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
5720 		    "reshape" :
5721 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
5722 		     "check" :
5723 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
5724 		      "resync" : "recovery"))),
5725 		   per_milli/10, per_milli % 10,
5726 		   (unsigned long long) resync/2,
5727 		   (unsigned long long) max_sectors/2);
5728 
5729 	/*
5730 	 * dt: time from mark until now
5731 	 * db: blocks written from mark until now
5732 	 * rt: remaining time
5733 	 *
5734 	 * rt is a sector_t, so could be 32bit or 64bit.
5735 	 * So we divide before multiply in case it is 32bit and close
5736 	 * to the limit.
5737 	 * We scale the divisor (db) by 32 to avoid loosing precision
5738 	 * near the end of resync when the number of remaining sectors
5739 	 * is close to 'db'.
5740 	 * We then divide rt by 32 after multiplying by db to compensate.
5741 	 * The '+1' avoids division by zero if db is very small.
5742 	 */
5743 	dt = ((jiffies - mddev->resync_mark) / HZ);
5744 	if (!dt) dt++;
5745 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
5746 		- mddev->resync_mark_cnt;
5747 
5748 	rt = max_sectors - resync;    /* number of remaining sectors */
5749 	sector_div(rt, db/32+1);
5750 	rt *= dt;
5751 	rt >>= 5;
5752 
5753 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
5754 		   ((unsigned long)rt % 60)/6);
5755 
5756 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
5757 }
5758 
5759 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
5760 {
5761 	struct list_head *tmp;
5762 	loff_t l = *pos;
5763 	mddev_t *mddev;
5764 
5765 	if (l >= 0x10000)
5766 		return NULL;
5767 	if (!l--)
5768 		/* header */
5769 		return (void*)1;
5770 
5771 	spin_lock(&all_mddevs_lock);
5772 	list_for_each(tmp,&all_mddevs)
5773 		if (!l--) {
5774 			mddev = list_entry(tmp, mddev_t, all_mddevs);
5775 			mddev_get(mddev);
5776 			spin_unlock(&all_mddevs_lock);
5777 			return mddev;
5778 		}
5779 	spin_unlock(&all_mddevs_lock);
5780 	if (!l--)
5781 		return (void*)2;/* tail */
5782 	return NULL;
5783 }
5784 
5785 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
5786 {
5787 	struct list_head *tmp;
5788 	mddev_t *next_mddev, *mddev = v;
5789 
5790 	++*pos;
5791 	if (v == (void*)2)
5792 		return NULL;
5793 
5794 	spin_lock(&all_mddevs_lock);
5795 	if (v == (void*)1)
5796 		tmp = all_mddevs.next;
5797 	else
5798 		tmp = mddev->all_mddevs.next;
5799 	if (tmp != &all_mddevs)
5800 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
5801 	else {
5802 		next_mddev = (void*)2;
5803 		*pos = 0x10000;
5804 	}
5805 	spin_unlock(&all_mddevs_lock);
5806 
5807 	if (v != (void*)1)
5808 		mddev_put(mddev);
5809 	return next_mddev;
5810 
5811 }
5812 
5813 static void md_seq_stop(struct seq_file *seq, void *v)
5814 {
5815 	mddev_t *mddev = v;
5816 
5817 	if (mddev && v != (void*)1 && v != (void*)2)
5818 		mddev_put(mddev);
5819 }
5820 
5821 struct mdstat_info {
5822 	int event;
5823 };
5824 
5825 static int md_seq_show(struct seq_file *seq, void *v)
5826 {
5827 	mddev_t *mddev = v;
5828 	sector_t sectors;
5829 	mdk_rdev_t *rdev;
5830 	struct mdstat_info *mi = seq->private;
5831 	struct bitmap *bitmap;
5832 
5833 	if (v == (void*)1) {
5834 		struct mdk_personality *pers;
5835 		seq_printf(seq, "Personalities : ");
5836 		spin_lock(&pers_lock);
5837 		list_for_each_entry(pers, &pers_list, list)
5838 			seq_printf(seq, "[%s] ", pers->name);
5839 
5840 		spin_unlock(&pers_lock);
5841 		seq_printf(seq, "\n");
5842 		mi->event = atomic_read(&md_event_count);
5843 		return 0;
5844 	}
5845 	if (v == (void*)2) {
5846 		status_unused(seq);
5847 		return 0;
5848 	}
5849 
5850 	if (mddev_lock(mddev) < 0)
5851 		return -EINTR;
5852 
5853 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
5854 		seq_printf(seq, "%s : %sactive", mdname(mddev),
5855 						mddev->pers ? "" : "in");
5856 		if (mddev->pers) {
5857 			if (mddev->ro==1)
5858 				seq_printf(seq, " (read-only)");
5859 			if (mddev->ro==2)
5860 				seq_printf(seq, " (auto-read-only)");
5861 			seq_printf(seq, " %s", mddev->pers->name);
5862 		}
5863 
5864 		sectors = 0;
5865 		list_for_each_entry(rdev, &mddev->disks, same_set) {
5866 			char b[BDEVNAME_SIZE];
5867 			seq_printf(seq, " %s[%d]",
5868 				bdevname(rdev->bdev,b), rdev->desc_nr);
5869 			if (test_bit(WriteMostly, &rdev->flags))
5870 				seq_printf(seq, "(W)");
5871 			if (test_bit(Faulty, &rdev->flags)) {
5872 				seq_printf(seq, "(F)");
5873 				continue;
5874 			} else if (rdev->raid_disk < 0)
5875 				seq_printf(seq, "(S)"); /* spare */
5876 			sectors += rdev->sectors;
5877 		}
5878 
5879 		if (!list_empty(&mddev->disks)) {
5880 			if (mddev->pers)
5881 				seq_printf(seq, "\n      %llu blocks",
5882 					   (unsigned long long)
5883 					   mddev->array_sectors / 2);
5884 			else
5885 				seq_printf(seq, "\n      %llu blocks",
5886 					   (unsigned long long)sectors / 2);
5887 		}
5888 		if (mddev->persistent) {
5889 			if (mddev->major_version != 0 ||
5890 			    mddev->minor_version != 90) {
5891 				seq_printf(seq," super %d.%d",
5892 					   mddev->major_version,
5893 					   mddev->minor_version);
5894 			}
5895 		} else if (mddev->external)
5896 			seq_printf(seq, " super external:%s",
5897 				   mddev->metadata_type);
5898 		else
5899 			seq_printf(seq, " super non-persistent");
5900 
5901 		if (mddev->pers) {
5902 			mddev->pers->status(seq, mddev);
5903 	 		seq_printf(seq, "\n      ");
5904 			if (mddev->pers->sync_request) {
5905 				if (mddev->curr_resync > 2) {
5906 					status_resync(seq, mddev);
5907 					seq_printf(seq, "\n      ");
5908 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
5909 					seq_printf(seq, "\tresync=DELAYED\n      ");
5910 				else if (mddev->recovery_cp < MaxSector)
5911 					seq_printf(seq, "\tresync=PENDING\n      ");
5912 			}
5913 		} else
5914 			seq_printf(seq, "\n       ");
5915 
5916 		if ((bitmap = mddev->bitmap)) {
5917 			unsigned long chunk_kb;
5918 			unsigned long flags;
5919 			spin_lock_irqsave(&bitmap->lock, flags);
5920 			chunk_kb = bitmap->chunksize >> 10;
5921 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
5922 				"%lu%s chunk",
5923 				bitmap->pages - bitmap->missing_pages,
5924 				bitmap->pages,
5925 				(bitmap->pages - bitmap->missing_pages)
5926 					<< (PAGE_SHIFT - 10),
5927 				chunk_kb ? chunk_kb : bitmap->chunksize,
5928 				chunk_kb ? "KB" : "B");
5929 			if (bitmap->file) {
5930 				seq_printf(seq, ", file: ");
5931 				seq_path(seq, &bitmap->file->f_path, " \t\n");
5932 			}
5933 
5934 			seq_printf(seq, "\n");
5935 			spin_unlock_irqrestore(&bitmap->lock, flags);
5936 		}
5937 
5938 		seq_printf(seq, "\n");
5939 	}
5940 	mddev_unlock(mddev);
5941 
5942 	return 0;
5943 }
5944 
5945 static const struct seq_operations md_seq_ops = {
5946 	.start  = md_seq_start,
5947 	.next   = md_seq_next,
5948 	.stop   = md_seq_stop,
5949 	.show   = md_seq_show,
5950 };
5951 
5952 static int md_seq_open(struct inode *inode, struct file *file)
5953 {
5954 	int error;
5955 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
5956 	if (mi == NULL)
5957 		return -ENOMEM;
5958 
5959 	error = seq_open(file, &md_seq_ops);
5960 	if (error)
5961 		kfree(mi);
5962 	else {
5963 		struct seq_file *p = file->private_data;
5964 		p->private = mi;
5965 		mi->event = atomic_read(&md_event_count);
5966 	}
5967 	return error;
5968 }
5969 
5970 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
5971 {
5972 	struct seq_file *m = filp->private_data;
5973 	struct mdstat_info *mi = m->private;
5974 	int mask;
5975 
5976 	poll_wait(filp, &md_event_waiters, wait);
5977 
5978 	/* always allow read */
5979 	mask = POLLIN | POLLRDNORM;
5980 
5981 	if (mi->event != atomic_read(&md_event_count))
5982 		mask |= POLLERR | POLLPRI;
5983 	return mask;
5984 }
5985 
5986 static const struct file_operations md_seq_fops = {
5987 	.owner		= THIS_MODULE,
5988 	.open           = md_seq_open,
5989 	.read           = seq_read,
5990 	.llseek         = seq_lseek,
5991 	.release	= seq_release_private,
5992 	.poll		= mdstat_poll,
5993 };
5994 
5995 int register_md_personality(struct mdk_personality *p)
5996 {
5997 	spin_lock(&pers_lock);
5998 	list_add_tail(&p->list, &pers_list);
5999 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6000 	spin_unlock(&pers_lock);
6001 	return 0;
6002 }
6003 
6004 int unregister_md_personality(struct mdk_personality *p)
6005 {
6006 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6007 	spin_lock(&pers_lock);
6008 	list_del_init(&p->list);
6009 	spin_unlock(&pers_lock);
6010 	return 0;
6011 }
6012 
6013 static int is_mddev_idle(mddev_t *mddev, int init)
6014 {
6015 	mdk_rdev_t * rdev;
6016 	int idle;
6017 	int curr_events;
6018 
6019 	idle = 1;
6020 	rcu_read_lock();
6021 	rdev_for_each_rcu(rdev, mddev) {
6022 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6023 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6024 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6025 			      atomic_read(&disk->sync_io);
6026 		/* sync IO will cause sync_io to increase before the disk_stats
6027 		 * as sync_io is counted when a request starts, and
6028 		 * disk_stats is counted when it completes.
6029 		 * So resync activity will cause curr_events to be smaller than
6030 		 * when there was no such activity.
6031 		 * non-sync IO will cause disk_stat to increase without
6032 		 * increasing sync_io so curr_events will (eventually)
6033 		 * be larger than it was before.  Once it becomes
6034 		 * substantially larger, the test below will cause
6035 		 * the array to appear non-idle, and resync will slow
6036 		 * down.
6037 		 * If there is a lot of outstanding resync activity when
6038 		 * we set last_event to curr_events, then all that activity
6039 		 * completing might cause the array to appear non-idle
6040 		 * and resync will be slowed down even though there might
6041 		 * not have been non-resync activity.  This will only
6042 		 * happen once though.  'last_events' will soon reflect
6043 		 * the state where there is little or no outstanding
6044 		 * resync requests, and further resync activity will
6045 		 * always make curr_events less than last_events.
6046 		 *
6047 		 */
6048 		if (init || curr_events - rdev->last_events > 64) {
6049 			rdev->last_events = curr_events;
6050 			idle = 0;
6051 		}
6052 	}
6053 	rcu_read_unlock();
6054 	return idle;
6055 }
6056 
6057 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6058 {
6059 	/* another "blocks" (512byte) blocks have been synced */
6060 	atomic_sub(blocks, &mddev->recovery_active);
6061 	wake_up(&mddev->recovery_wait);
6062 	if (!ok) {
6063 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6064 		md_wakeup_thread(mddev->thread);
6065 		// stop recovery, signal do_sync ....
6066 	}
6067 }
6068 
6069 
6070 /* md_write_start(mddev, bi)
6071  * If we need to update some array metadata (e.g. 'active' flag
6072  * in superblock) before writing, schedule a superblock update
6073  * and wait for it to complete.
6074  */
6075 void md_write_start(mddev_t *mddev, struct bio *bi)
6076 {
6077 	int did_change = 0;
6078 	if (bio_data_dir(bi) != WRITE)
6079 		return;
6080 
6081 	BUG_ON(mddev->ro == 1);
6082 	if (mddev->ro == 2) {
6083 		/* need to switch to read/write */
6084 		mddev->ro = 0;
6085 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6086 		md_wakeup_thread(mddev->thread);
6087 		md_wakeup_thread(mddev->sync_thread);
6088 		did_change = 1;
6089 	}
6090 	atomic_inc(&mddev->writes_pending);
6091 	if (mddev->safemode == 1)
6092 		mddev->safemode = 0;
6093 	if (mddev->in_sync) {
6094 		spin_lock_irq(&mddev->write_lock);
6095 		if (mddev->in_sync) {
6096 			mddev->in_sync = 0;
6097 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6098 			md_wakeup_thread(mddev->thread);
6099 			did_change = 1;
6100 		}
6101 		spin_unlock_irq(&mddev->write_lock);
6102 	}
6103 	if (did_change)
6104 		sysfs_notify_dirent(mddev->sysfs_state);
6105 	wait_event(mddev->sb_wait,
6106 		   !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
6107 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6108 }
6109 
6110 void md_write_end(mddev_t *mddev)
6111 {
6112 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6113 		if (mddev->safemode == 2)
6114 			md_wakeup_thread(mddev->thread);
6115 		else if (mddev->safemode_delay)
6116 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6117 	}
6118 }
6119 
6120 /* md_allow_write(mddev)
6121  * Calling this ensures that the array is marked 'active' so that writes
6122  * may proceed without blocking.  It is important to call this before
6123  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6124  * Must be called with mddev_lock held.
6125  *
6126  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6127  * is dropped, so return -EAGAIN after notifying userspace.
6128  */
6129 int md_allow_write(mddev_t *mddev)
6130 {
6131 	if (!mddev->pers)
6132 		return 0;
6133 	if (mddev->ro)
6134 		return 0;
6135 	if (!mddev->pers->sync_request)
6136 		return 0;
6137 
6138 	spin_lock_irq(&mddev->write_lock);
6139 	if (mddev->in_sync) {
6140 		mddev->in_sync = 0;
6141 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6142 		if (mddev->safemode_delay &&
6143 		    mddev->safemode == 0)
6144 			mddev->safemode = 1;
6145 		spin_unlock_irq(&mddev->write_lock);
6146 		md_update_sb(mddev, 0);
6147 		sysfs_notify_dirent(mddev->sysfs_state);
6148 	} else
6149 		spin_unlock_irq(&mddev->write_lock);
6150 
6151 	if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
6152 		return -EAGAIN;
6153 	else
6154 		return 0;
6155 }
6156 EXPORT_SYMBOL_GPL(md_allow_write);
6157 
6158 #define SYNC_MARKS	10
6159 #define	SYNC_MARK_STEP	(3*HZ)
6160 void md_do_sync(mddev_t *mddev)
6161 {
6162 	mddev_t *mddev2;
6163 	unsigned int currspeed = 0,
6164 		 window;
6165 	sector_t max_sectors,j, io_sectors;
6166 	unsigned long mark[SYNC_MARKS];
6167 	sector_t mark_cnt[SYNC_MARKS];
6168 	int last_mark,m;
6169 	struct list_head *tmp;
6170 	sector_t last_check;
6171 	int skipped = 0;
6172 	mdk_rdev_t *rdev;
6173 	char *desc;
6174 
6175 	/* just incase thread restarts... */
6176 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6177 		return;
6178 	if (mddev->ro) /* never try to sync a read-only array */
6179 		return;
6180 
6181 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6182 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6183 			desc = "data-check";
6184 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6185 			desc = "requested-resync";
6186 		else
6187 			desc = "resync";
6188 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6189 		desc = "reshape";
6190 	else
6191 		desc = "recovery";
6192 
6193 	/* we overload curr_resync somewhat here.
6194 	 * 0 == not engaged in resync at all
6195 	 * 2 == checking that there is no conflict with another sync
6196 	 * 1 == like 2, but have yielded to allow conflicting resync to
6197 	 *		commense
6198 	 * other == active in resync - this many blocks
6199 	 *
6200 	 * Before starting a resync we must have set curr_resync to
6201 	 * 2, and then checked that every "conflicting" array has curr_resync
6202 	 * less than ours.  When we find one that is the same or higher
6203 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6204 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6205 	 * This will mean we have to start checking from the beginning again.
6206 	 *
6207 	 */
6208 
6209 	do {
6210 		mddev->curr_resync = 2;
6211 
6212 	try_again:
6213 		if (kthread_should_stop()) {
6214 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6215 			goto skip;
6216 		}
6217 		for_each_mddev(mddev2, tmp) {
6218 			if (mddev2 == mddev)
6219 				continue;
6220 			if (!mddev->parallel_resync
6221 			&&  mddev2->curr_resync
6222 			&&  match_mddev_units(mddev, mddev2)) {
6223 				DEFINE_WAIT(wq);
6224 				if (mddev < mddev2 && mddev->curr_resync == 2) {
6225 					/* arbitrarily yield */
6226 					mddev->curr_resync = 1;
6227 					wake_up(&resync_wait);
6228 				}
6229 				if (mddev > mddev2 && mddev->curr_resync == 1)
6230 					/* no need to wait here, we can wait the next
6231 					 * time 'round when curr_resync == 2
6232 					 */
6233 					continue;
6234 				/* We need to wait 'interruptible' so as not to
6235 				 * contribute to the load average, and not to
6236 				 * be caught by 'softlockup'
6237 				 */
6238 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
6239 				if (!kthread_should_stop() &&
6240 				    mddev2->curr_resync >= mddev->curr_resync) {
6241 					printk(KERN_INFO "md: delaying %s of %s"
6242 					       " until %s has finished (they"
6243 					       " share one or more physical units)\n",
6244 					       desc, mdname(mddev), mdname(mddev2));
6245 					mddev_put(mddev2);
6246 					if (signal_pending(current))
6247 						flush_signals(current);
6248 					schedule();
6249 					finish_wait(&resync_wait, &wq);
6250 					goto try_again;
6251 				}
6252 				finish_wait(&resync_wait, &wq);
6253 			}
6254 		}
6255 	} while (mddev->curr_resync < 2);
6256 
6257 	j = 0;
6258 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6259 		/* resync follows the size requested by the personality,
6260 		 * which defaults to physical size, but can be virtual size
6261 		 */
6262 		max_sectors = mddev->resync_max_sectors;
6263 		mddev->resync_mismatches = 0;
6264 		/* we don't use the checkpoint if there's a bitmap */
6265 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6266 			j = mddev->resync_min;
6267 		else if (!mddev->bitmap)
6268 			j = mddev->recovery_cp;
6269 
6270 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6271 		max_sectors = mddev->dev_sectors;
6272 	else {
6273 		/* recovery follows the physical size of devices */
6274 		max_sectors = mddev->dev_sectors;
6275 		j = MaxSector;
6276 		list_for_each_entry(rdev, &mddev->disks, same_set)
6277 			if (rdev->raid_disk >= 0 &&
6278 			    !test_bit(Faulty, &rdev->flags) &&
6279 			    !test_bit(In_sync, &rdev->flags) &&
6280 			    rdev->recovery_offset < j)
6281 				j = rdev->recovery_offset;
6282 	}
6283 
6284 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
6285 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
6286 		" %d KB/sec/disk.\n", speed_min(mddev));
6287 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6288 	       "(but not more than %d KB/sec) for %s.\n",
6289 	       speed_max(mddev), desc);
6290 
6291 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
6292 
6293 	io_sectors = 0;
6294 	for (m = 0; m < SYNC_MARKS; m++) {
6295 		mark[m] = jiffies;
6296 		mark_cnt[m] = io_sectors;
6297 	}
6298 	last_mark = 0;
6299 	mddev->resync_mark = mark[last_mark];
6300 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6301 
6302 	/*
6303 	 * Tune reconstruction:
6304 	 */
6305 	window = 32*(PAGE_SIZE/512);
6306 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6307 		window/2,(unsigned long long) max_sectors/2);
6308 
6309 	atomic_set(&mddev->recovery_active, 0);
6310 	last_check = 0;
6311 
6312 	if (j>2) {
6313 		printk(KERN_INFO
6314 		       "md: resuming %s of %s from checkpoint.\n",
6315 		       desc, mdname(mddev));
6316 		mddev->curr_resync = j;
6317 	}
6318 
6319 	while (j < max_sectors) {
6320 		sector_t sectors;
6321 
6322 		skipped = 0;
6323 
6324 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6325 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
6326 		      (mddev->curr_resync - mddev->curr_resync_completed)
6327 		      > (max_sectors >> 4)) ||
6328 		     (j - mddev->curr_resync_completed)*2
6329 		     >= mddev->resync_max - mddev->curr_resync_completed
6330 			    )) {
6331 			/* time to update curr_resync_completed */
6332 			blk_unplug(mddev->queue);
6333 			wait_event(mddev->recovery_wait,
6334 				   atomic_read(&mddev->recovery_active) == 0);
6335 			mddev->curr_resync_completed =
6336 				mddev->curr_resync;
6337 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6338 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6339 		}
6340 
6341 		while (j >= mddev->resync_max && !kthread_should_stop()) {
6342 			/* As this condition is controlled by user-space,
6343 			 * we can block indefinitely, so use '_interruptible'
6344 			 * to avoid triggering warnings.
6345 			 */
6346 			flush_signals(current); /* just in case */
6347 			wait_event_interruptible(mddev->recovery_wait,
6348 						 mddev->resync_max > j
6349 						 || kthread_should_stop());
6350 		}
6351 
6352 		if (kthread_should_stop())
6353 			goto interrupted;
6354 
6355 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6356 						  currspeed < speed_min(mddev));
6357 		if (sectors == 0) {
6358 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6359 			goto out;
6360 		}
6361 
6362 		if (!skipped) { /* actual IO requested */
6363 			io_sectors += sectors;
6364 			atomic_add(sectors, &mddev->recovery_active);
6365 		}
6366 
6367 		j += sectors;
6368 		if (j>1) mddev->curr_resync = j;
6369 		mddev->curr_mark_cnt = io_sectors;
6370 		if (last_check == 0)
6371 			/* this is the earliers that rebuilt will be
6372 			 * visible in /proc/mdstat
6373 			 */
6374 			md_new_event(mddev);
6375 
6376 		if (last_check + window > io_sectors || j == max_sectors)
6377 			continue;
6378 
6379 		last_check = io_sectors;
6380 
6381 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6382 			break;
6383 
6384 	repeat:
6385 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6386 			/* step marks */
6387 			int next = (last_mark+1) % SYNC_MARKS;
6388 
6389 			mddev->resync_mark = mark[next];
6390 			mddev->resync_mark_cnt = mark_cnt[next];
6391 			mark[next] = jiffies;
6392 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6393 			last_mark = next;
6394 		}
6395 
6396 
6397 		if (kthread_should_stop())
6398 			goto interrupted;
6399 
6400 
6401 		/*
6402 		 * this loop exits only if either when we are slower than
6403 		 * the 'hard' speed limit, or the system was IO-idle for
6404 		 * a jiffy.
6405 		 * the system might be non-idle CPU-wise, but we only care
6406 		 * about not overloading the IO subsystem. (things like an
6407 		 * e2fsck being done on the RAID array should execute fast)
6408 		 */
6409 		blk_unplug(mddev->queue);
6410 		cond_resched();
6411 
6412 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6413 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6414 
6415 		if (currspeed > speed_min(mddev)) {
6416 			if ((currspeed > speed_max(mddev)) ||
6417 					!is_mddev_idle(mddev, 0)) {
6418 				msleep(500);
6419 				goto repeat;
6420 			}
6421 		}
6422 	}
6423 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6424 	/*
6425 	 * this also signals 'finished resyncing' to md_stop
6426 	 */
6427  out:
6428 	blk_unplug(mddev->queue);
6429 
6430 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6431 
6432 	/* tell personality that we are finished */
6433 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6434 
6435 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6436 	    mddev->curr_resync > 2) {
6437 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6438 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6439 				if (mddev->curr_resync >= mddev->recovery_cp) {
6440 					printk(KERN_INFO
6441 					       "md: checkpointing %s of %s.\n",
6442 					       desc, mdname(mddev));
6443 					mddev->recovery_cp = mddev->curr_resync;
6444 				}
6445 			} else
6446 				mddev->recovery_cp = MaxSector;
6447 		} else {
6448 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6449 				mddev->curr_resync = MaxSector;
6450 			list_for_each_entry(rdev, &mddev->disks, same_set)
6451 				if (rdev->raid_disk >= 0 &&
6452 				    !test_bit(Faulty, &rdev->flags) &&
6453 				    !test_bit(In_sync, &rdev->flags) &&
6454 				    rdev->recovery_offset < mddev->curr_resync)
6455 					rdev->recovery_offset = mddev->curr_resync;
6456 		}
6457 	}
6458 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6459 
6460  skip:
6461 	mddev->curr_resync = 0;
6462 	mddev->curr_resync_completed = 0;
6463 	mddev->resync_min = 0;
6464 	mddev->resync_max = MaxSector;
6465 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6466 	wake_up(&resync_wait);
6467 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6468 	md_wakeup_thread(mddev->thread);
6469 	return;
6470 
6471  interrupted:
6472 	/*
6473 	 * got a signal, exit.
6474 	 */
6475 	printk(KERN_INFO
6476 	       "md: md_do_sync() got signal ... exiting\n");
6477 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6478 	goto out;
6479 
6480 }
6481 EXPORT_SYMBOL_GPL(md_do_sync);
6482 
6483 
6484 static int remove_and_add_spares(mddev_t *mddev)
6485 {
6486 	mdk_rdev_t *rdev;
6487 	int spares = 0;
6488 
6489 	mddev->curr_resync_completed = 0;
6490 
6491 	list_for_each_entry(rdev, &mddev->disks, same_set)
6492 		if (rdev->raid_disk >= 0 &&
6493 		    !test_bit(Blocked, &rdev->flags) &&
6494 		    (test_bit(Faulty, &rdev->flags) ||
6495 		     ! test_bit(In_sync, &rdev->flags)) &&
6496 		    atomic_read(&rdev->nr_pending)==0) {
6497 			if (mddev->pers->hot_remove_disk(
6498 				    mddev, rdev->raid_disk)==0) {
6499 				char nm[20];
6500 				sprintf(nm,"rd%d", rdev->raid_disk);
6501 				sysfs_remove_link(&mddev->kobj, nm);
6502 				rdev->raid_disk = -1;
6503 			}
6504 		}
6505 
6506 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
6507 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6508 			if (rdev->raid_disk >= 0 &&
6509 			    !test_bit(In_sync, &rdev->flags) &&
6510 			    !test_bit(Blocked, &rdev->flags))
6511 				spares++;
6512 			if (rdev->raid_disk < 0
6513 			    && !test_bit(Faulty, &rdev->flags)) {
6514 				rdev->recovery_offset = 0;
6515 				if (mddev->pers->
6516 				    hot_add_disk(mddev, rdev) == 0) {
6517 					char nm[20];
6518 					sprintf(nm, "rd%d", rdev->raid_disk);
6519 					if (sysfs_create_link(&mddev->kobj,
6520 							      &rdev->kobj, nm))
6521 						printk(KERN_WARNING
6522 						       "md: cannot register "
6523 						       "%s for %s\n",
6524 						       nm, mdname(mddev));
6525 					spares++;
6526 					md_new_event(mddev);
6527 				} else
6528 					break;
6529 			}
6530 		}
6531 	}
6532 	return spares;
6533 }
6534 /*
6535  * This routine is regularly called by all per-raid-array threads to
6536  * deal with generic issues like resync and super-block update.
6537  * Raid personalities that don't have a thread (linear/raid0) do not
6538  * need this as they never do any recovery or update the superblock.
6539  *
6540  * It does not do any resync itself, but rather "forks" off other threads
6541  * to do that as needed.
6542  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
6543  * "->recovery" and create a thread at ->sync_thread.
6544  * When the thread finishes it sets MD_RECOVERY_DONE
6545  * and wakeups up this thread which will reap the thread and finish up.
6546  * This thread also removes any faulty devices (with nr_pending == 0).
6547  *
6548  * The overall approach is:
6549  *  1/ if the superblock needs updating, update it.
6550  *  2/ If a recovery thread is running, don't do anything else.
6551  *  3/ If recovery has finished, clean up, possibly marking spares active.
6552  *  4/ If there are any faulty devices, remove them.
6553  *  5/ If array is degraded, try to add spares devices
6554  *  6/ If array has spares or is not in-sync, start a resync thread.
6555  */
6556 void md_check_recovery(mddev_t *mddev)
6557 {
6558 	mdk_rdev_t *rdev;
6559 
6560 
6561 	if (mddev->bitmap)
6562 		bitmap_daemon_work(mddev->bitmap);
6563 
6564 	if (mddev->ro)
6565 		return;
6566 
6567 	if (signal_pending(current)) {
6568 		if (mddev->pers->sync_request && !mddev->external) {
6569 			printk(KERN_INFO "md: %s in immediate safe mode\n",
6570 			       mdname(mddev));
6571 			mddev->safemode = 2;
6572 		}
6573 		flush_signals(current);
6574 	}
6575 
6576 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
6577 		return;
6578 	if ( ! (
6579 		(mddev->flags && !mddev->external) ||
6580 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
6581 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
6582 		(mddev->external == 0 && mddev->safemode == 1) ||
6583 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
6584 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
6585 		))
6586 		return;
6587 
6588 	if (mddev_trylock(mddev)) {
6589 		int spares = 0;
6590 
6591 		if (mddev->ro) {
6592 			/* Only thing we do on a ro array is remove
6593 			 * failed devices.
6594 			 */
6595 			remove_and_add_spares(mddev);
6596 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6597 			goto unlock;
6598 		}
6599 
6600 		if (!mddev->external) {
6601 			int did_change = 0;
6602 			spin_lock_irq(&mddev->write_lock);
6603 			if (mddev->safemode &&
6604 			    !atomic_read(&mddev->writes_pending) &&
6605 			    !mddev->in_sync &&
6606 			    mddev->recovery_cp == MaxSector) {
6607 				mddev->in_sync = 1;
6608 				did_change = 1;
6609 				if (mddev->persistent)
6610 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6611 			}
6612 			if (mddev->safemode == 1)
6613 				mddev->safemode = 0;
6614 			spin_unlock_irq(&mddev->write_lock);
6615 			if (did_change)
6616 				sysfs_notify_dirent(mddev->sysfs_state);
6617 		}
6618 
6619 		if (mddev->flags)
6620 			md_update_sb(mddev, 0);
6621 
6622 		list_for_each_entry(rdev, &mddev->disks, same_set)
6623 			if (test_and_clear_bit(StateChanged, &rdev->flags))
6624 				sysfs_notify_dirent(rdev->sysfs_state);
6625 
6626 
6627 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
6628 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
6629 			/* resync/recovery still happening */
6630 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6631 			goto unlock;
6632 		}
6633 		if (mddev->sync_thread) {
6634 			/* resync has finished, collect result */
6635 			md_unregister_thread(mddev->sync_thread);
6636 			mddev->sync_thread = NULL;
6637 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
6638 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
6639 				/* success...*/
6640 				/* activate any spares */
6641 				if (mddev->pers->spare_active(mddev))
6642 					sysfs_notify(&mddev->kobj, NULL,
6643 						     "degraded");
6644 			}
6645 			if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
6646 			    mddev->pers->finish_reshape)
6647 				mddev->pers->finish_reshape(mddev);
6648 			md_update_sb(mddev, 1);
6649 
6650 			/* if array is no-longer degraded, then any saved_raid_disk
6651 			 * information must be scrapped
6652 			 */
6653 			if (!mddev->degraded)
6654 				list_for_each_entry(rdev, &mddev->disks, same_set)
6655 					rdev->saved_raid_disk = -1;
6656 
6657 			mddev->recovery = 0;
6658 			/* flag recovery needed just to double check */
6659 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6660 			sysfs_notify_dirent(mddev->sysfs_action);
6661 			md_new_event(mddev);
6662 			goto unlock;
6663 		}
6664 		/* Set RUNNING before clearing NEEDED to avoid
6665 		 * any transients in the value of "sync_action".
6666 		 */
6667 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6668 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6669 		/* Clear some bits that don't mean anything, but
6670 		 * might be left set
6671 		 */
6672 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
6673 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
6674 
6675 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
6676 			goto unlock;
6677 		/* no recovery is running.
6678 		 * remove any failed drives, then
6679 		 * add spares if possible.
6680 		 * Spare are also removed and re-added, to allow
6681 		 * the personality to fail the re-add.
6682 		 */
6683 
6684 		if (mddev->reshape_position != MaxSector) {
6685 			if (mddev->pers->check_reshape == NULL ||
6686 			    mddev->pers->check_reshape(mddev) != 0)
6687 				/* Cannot proceed */
6688 				goto unlock;
6689 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6690 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6691 		} else if ((spares = remove_and_add_spares(mddev))) {
6692 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6693 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6694 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
6695 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6696 		} else if (mddev->recovery_cp < MaxSector) {
6697 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6698 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6699 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6700 			/* nothing to be done ... */
6701 			goto unlock;
6702 
6703 		if (mddev->pers->sync_request) {
6704 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
6705 				/* We are adding a device or devices to an array
6706 				 * which has the bitmap stored on all devices.
6707 				 * So make sure all bitmap pages get written
6708 				 */
6709 				bitmap_write_all(mddev->bitmap);
6710 			}
6711 			mddev->sync_thread = md_register_thread(md_do_sync,
6712 								mddev,
6713 								"%s_resync");
6714 			if (!mddev->sync_thread) {
6715 				printk(KERN_ERR "%s: could not start resync"
6716 					" thread...\n",
6717 					mdname(mddev));
6718 				/* leave the spares where they are, it shouldn't hurt */
6719 				mddev->recovery = 0;
6720 			} else
6721 				md_wakeup_thread(mddev->sync_thread);
6722 			sysfs_notify_dirent(mddev->sysfs_action);
6723 			md_new_event(mddev);
6724 		}
6725 	unlock:
6726 		if (!mddev->sync_thread) {
6727 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6728 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
6729 					       &mddev->recovery))
6730 				if (mddev->sysfs_action)
6731 					sysfs_notify_dirent(mddev->sysfs_action);
6732 		}
6733 		mddev_unlock(mddev);
6734 	}
6735 }
6736 
6737 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
6738 {
6739 	sysfs_notify_dirent(rdev->sysfs_state);
6740 	wait_event_timeout(rdev->blocked_wait,
6741 			   !test_bit(Blocked, &rdev->flags),
6742 			   msecs_to_jiffies(5000));
6743 	rdev_dec_pending(rdev, mddev);
6744 }
6745 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
6746 
6747 static int md_notify_reboot(struct notifier_block *this,
6748 			    unsigned long code, void *x)
6749 {
6750 	struct list_head *tmp;
6751 	mddev_t *mddev;
6752 
6753 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
6754 
6755 		printk(KERN_INFO "md: stopping all md devices.\n");
6756 
6757 		for_each_mddev(mddev, tmp)
6758 			if (mddev_trylock(mddev)) {
6759 				/* Force a switch to readonly even array
6760 				 * appears to still be in use.  Hence
6761 				 * the '100'.
6762 				 */
6763 				do_md_stop(mddev, 1, 100);
6764 				mddev_unlock(mddev);
6765 			}
6766 		/*
6767 		 * certain more exotic SCSI devices are known to be
6768 		 * volatile wrt too early system reboots. While the
6769 		 * right place to handle this issue is the given
6770 		 * driver, we do want to have a safe RAID driver ...
6771 		 */
6772 		mdelay(1000*1);
6773 	}
6774 	return NOTIFY_DONE;
6775 }
6776 
6777 static struct notifier_block md_notifier = {
6778 	.notifier_call	= md_notify_reboot,
6779 	.next		= NULL,
6780 	.priority	= INT_MAX, /* before any real devices */
6781 };
6782 
6783 static void md_geninit(void)
6784 {
6785 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
6786 
6787 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
6788 }
6789 
6790 static int __init md_init(void)
6791 {
6792 	if (register_blkdev(MD_MAJOR, "md"))
6793 		return -1;
6794 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
6795 		unregister_blkdev(MD_MAJOR, "md");
6796 		return -1;
6797 	}
6798 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
6799 			    md_probe, NULL, NULL);
6800 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
6801 			    md_probe, NULL, NULL);
6802 
6803 	register_reboot_notifier(&md_notifier);
6804 	raid_table_header = register_sysctl_table(raid_root_table);
6805 
6806 	md_geninit();
6807 	return 0;
6808 }
6809 
6810 
6811 #ifndef MODULE
6812 
6813 /*
6814  * Searches all registered partitions for autorun RAID arrays
6815  * at boot time.
6816  */
6817 
6818 static LIST_HEAD(all_detected_devices);
6819 struct detected_devices_node {
6820 	struct list_head list;
6821 	dev_t dev;
6822 };
6823 
6824 void md_autodetect_dev(dev_t dev)
6825 {
6826 	struct detected_devices_node *node_detected_dev;
6827 
6828 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
6829 	if (node_detected_dev) {
6830 		node_detected_dev->dev = dev;
6831 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
6832 	} else {
6833 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
6834 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
6835 	}
6836 }
6837 
6838 
6839 static void autostart_arrays(int part)
6840 {
6841 	mdk_rdev_t *rdev;
6842 	struct detected_devices_node *node_detected_dev;
6843 	dev_t dev;
6844 	int i_scanned, i_passed;
6845 
6846 	i_scanned = 0;
6847 	i_passed = 0;
6848 
6849 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
6850 
6851 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
6852 		i_scanned++;
6853 		node_detected_dev = list_entry(all_detected_devices.next,
6854 					struct detected_devices_node, list);
6855 		list_del(&node_detected_dev->list);
6856 		dev = node_detected_dev->dev;
6857 		kfree(node_detected_dev);
6858 		rdev = md_import_device(dev,0, 90);
6859 		if (IS_ERR(rdev))
6860 			continue;
6861 
6862 		if (test_bit(Faulty, &rdev->flags)) {
6863 			MD_BUG();
6864 			continue;
6865 		}
6866 		set_bit(AutoDetected, &rdev->flags);
6867 		list_add(&rdev->same_set, &pending_raid_disks);
6868 		i_passed++;
6869 	}
6870 
6871 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
6872 						i_scanned, i_passed);
6873 
6874 	autorun_devices(part);
6875 }
6876 
6877 #endif /* !MODULE */
6878 
6879 static __exit void md_exit(void)
6880 {
6881 	mddev_t *mddev;
6882 	struct list_head *tmp;
6883 
6884 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
6885 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
6886 
6887 	unregister_blkdev(MD_MAJOR,"md");
6888 	unregister_blkdev(mdp_major, "mdp");
6889 	unregister_reboot_notifier(&md_notifier);
6890 	unregister_sysctl_table(raid_table_header);
6891 	remove_proc_entry("mdstat", NULL);
6892 	for_each_mddev(mddev, tmp) {
6893 		export_array(mddev);
6894 		mddev->hold_active = 0;
6895 	}
6896 }
6897 
6898 subsys_initcall(md_init);
6899 module_exit(md_exit)
6900 
6901 static int get_ro(char *buffer, struct kernel_param *kp)
6902 {
6903 	return sprintf(buffer, "%d", start_readonly);
6904 }
6905 static int set_ro(const char *val, struct kernel_param *kp)
6906 {
6907 	char *e;
6908 	int num = simple_strtoul(val, &e, 10);
6909 	if (*val && (*e == '\0' || *e == '\n')) {
6910 		start_readonly = num;
6911 		return 0;
6912 	}
6913 	return -EINVAL;
6914 }
6915 
6916 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
6917 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
6918 
6919 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
6920 
6921 EXPORT_SYMBOL(register_md_personality);
6922 EXPORT_SYMBOL(unregister_md_personality);
6923 EXPORT_SYMBOL(md_error);
6924 EXPORT_SYMBOL(md_done_sync);
6925 EXPORT_SYMBOL(md_write_start);
6926 EXPORT_SYMBOL(md_write_end);
6927 EXPORT_SYMBOL(md_register_thread);
6928 EXPORT_SYMBOL(md_unregister_thread);
6929 EXPORT_SYMBOL(md_wakeup_thread);
6930 EXPORT_SYMBOL(md_check_recovery);
6931 MODULE_LICENSE("GPL");
6932 MODULE_ALIAS("md");
6933 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
6934