xref: /linux/drivers/md/md.c (revision ccea15f45eb0ab12d658f88b5d4be005cb2bb1a7)
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/module.h>
36 #include <linux/config.h>
37 #include <linux/kthread.h>
38 #include <linux/linkage.h>
39 #include <linux/raid/md.h>
40 #include <linux/raid/bitmap.h>
41 #include <linux/sysctl.h>
42 #include <linux/devfs_fs_kernel.h>
43 #include <linux/buffer_head.h> /* for invalidate_bdev */
44 #include <linux/suspend.h>
45 #include <linux/poll.h>
46 #include <linux/mutex.h>
47 
48 #include <linux/init.h>
49 
50 #include <linux/file.h>
51 
52 #ifdef CONFIG_KMOD
53 #include <linux/kmod.h>
54 #endif
55 
56 #include <asm/unaligned.h>
57 
58 #define MAJOR_NR MD_MAJOR
59 #define MD_DRIVER
60 
61 /* 63 partitions with the alternate major number (mdp) */
62 #define MdpMinorShift 6
63 
64 #define DEBUG 0
65 #define dprintk(x...) ((void)(DEBUG && printk(x)))
66 
67 
68 #ifndef MODULE
69 static void autostart_arrays (int part);
70 #endif
71 
72 static LIST_HEAD(pers_list);
73 static DEFINE_SPINLOCK(pers_lock);
74 
75 /*
76  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
77  * is 1000 KB/sec, so the extra system load does not show up that much.
78  * Increase it if you want to have more _guaranteed_ speed. Note that
79  * the RAID driver will use the maximum available bandwidth if the IO
80  * subsystem is idle. There is also an 'absolute maximum' reconstruction
81  * speed limit - in case reconstruction slows down your system despite
82  * idle IO detection.
83  *
84  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
85  * or /sys/block/mdX/md/sync_speed_{min,max}
86  */
87 
88 static int sysctl_speed_limit_min = 1000;
89 static int sysctl_speed_limit_max = 200000;
90 static inline int speed_min(mddev_t *mddev)
91 {
92 	return mddev->sync_speed_min ?
93 		mddev->sync_speed_min : sysctl_speed_limit_min;
94 }
95 
96 static inline int speed_max(mddev_t *mddev)
97 {
98 	return mddev->sync_speed_max ?
99 		mddev->sync_speed_max : sysctl_speed_limit_max;
100 }
101 
102 static struct ctl_table_header *raid_table_header;
103 
104 static ctl_table raid_table[] = {
105 	{
106 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MIN,
107 		.procname	= "speed_limit_min",
108 		.data		= &sysctl_speed_limit_min,
109 		.maxlen		= sizeof(int),
110 		.mode		= 0644,
111 		.proc_handler	= &proc_dointvec,
112 	},
113 	{
114 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MAX,
115 		.procname	= "speed_limit_max",
116 		.data		= &sysctl_speed_limit_max,
117 		.maxlen		= sizeof(int),
118 		.mode		= 0644,
119 		.proc_handler	= &proc_dointvec,
120 	},
121 	{ .ctl_name = 0 }
122 };
123 
124 static ctl_table raid_dir_table[] = {
125 	{
126 		.ctl_name	= DEV_RAID,
127 		.procname	= "raid",
128 		.maxlen		= 0,
129 		.mode		= 0555,
130 		.child		= raid_table,
131 	},
132 	{ .ctl_name = 0 }
133 };
134 
135 static ctl_table raid_root_table[] = {
136 	{
137 		.ctl_name	= CTL_DEV,
138 		.procname	= "dev",
139 		.maxlen		= 0,
140 		.mode		= 0555,
141 		.child		= raid_dir_table,
142 	},
143 	{ .ctl_name = 0 }
144 };
145 
146 static struct block_device_operations md_fops;
147 
148 static int start_readonly;
149 
150 /*
151  * We have a system wide 'event count' that is incremented
152  * on any 'interesting' event, and readers of /proc/mdstat
153  * can use 'poll' or 'select' to find out when the event
154  * count increases.
155  *
156  * Events are:
157  *  start array, stop array, error, add device, remove device,
158  *  start build, activate spare
159  */
160 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
161 static atomic_t md_event_count;
162 void md_new_event(mddev_t *mddev)
163 {
164 	atomic_inc(&md_event_count);
165 	wake_up(&md_event_waiters);
166 }
167 EXPORT_SYMBOL_GPL(md_new_event);
168 
169 /*
170  * Enables to iterate over all existing md arrays
171  * all_mddevs_lock protects this list.
172  */
173 static LIST_HEAD(all_mddevs);
174 static DEFINE_SPINLOCK(all_mddevs_lock);
175 
176 
177 /*
178  * iterates through all used mddevs in the system.
179  * We take care to grab the all_mddevs_lock whenever navigating
180  * the list, and to always hold a refcount when unlocked.
181  * Any code which breaks out of this loop while own
182  * a reference to the current mddev and must mddev_put it.
183  */
184 #define ITERATE_MDDEV(mddev,tmp)					\
185 									\
186 	for (({ spin_lock(&all_mddevs_lock); 				\
187 		tmp = all_mddevs.next;					\
188 		mddev = NULL;});					\
189 	     ({ if (tmp != &all_mddevs)					\
190 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
191 		spin_unlock(&all_mddevs_lock);				\
192 		if (mddev) mddev_put(mddev);				\
193 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
194 		tmp != &all_mddevs;});					\
195 	     ({ spin_lock(&all_mddevs_lock);				\
196 		tmp = tmp->next;})					\
197 		)
198 
199 
200 static int md_fail_request (request_queue_t *q, struct bio *bio)
201 {
202 	bio_io_error(bio, bio->bi_size);
203 	return 0;
204 }
205 
206 static inline mddev_t *mddev_get(mddev_t *mddev)
207 {
208 	atomic_inc(&mddev->active);
209 	return mddev;
210 }
211 
212 static void mddev_put(mddev_t *mddev)
213 {
214 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
215 		return;
216 	if (!mddev->raid_disks && list_empty(&mddev->disks)) {
217 		list_del(&mddev->all_mddevs);
218 		spin_unlock(&all_mddevs_lock);
219 		blk_cleanup_queue(mddev->queue);
220 		kobject_unregister(&mddev->kobj);
221 	} else
222 		spin_unlock(&all_mddevs_lock);
223 }
224 
225 static mddev_t * mddev_find(dev_t unit)
226 {
227 	mddev_t *mddev, *new = NULL;
228 
229  retry:
230 	spin_lock(&all_mddevs_lock);
231 	list_for_each_entry(mddev, &all_mddevs, all_mddevs)
232 		if (mddev->unit == unit) {
233 			mddev_get(mddev);
234 			spin_unlock(&all_mddevs_lock);
235 			kfree(new);
236 			return mddev;
237 		}
238 
239 	if (new) {
240 		list_add(&new->all_mddevs, &all_mddevs);
241 		spin_unlock(&all_mddevs_lock);
242 		return new;
243 	}
244 	spin_unlock(&all_mddevs_lock);
245 
246 	new = kzalloc(sizeof(*new), GFP_KERNEL);
247 	if (!new)
248 		return NULL;
249 
250 	new->unit = unit;
251 	if (MAJOR(unit) == MD_MAJOR)
252 		new->md_minor = MINOR(unit);
253 	else
254 		new->md_minor = MINOR(unit) >> MdpMinorShift;
255 
256 	mutex_init(&new->reconfig_mutex);
257 	INIT_LIST_HEAD(&new->disks);
258 	INIT_LIST_HEAD(&new->all_mddevs);
259 	init_timer(&new->safemode_timer);
260 	atomic_set(&new->active, 1);
261 	spin_lock_init(&new->write_lock);
262 	init_waitqueue_head(&new->sb_wait);
263 
264 	new->queue = blk_alloc_queue(GFP_KERNEL);
265 	if (!new->queue) {
266 		kfree(new);
267 		return NULL;
268 	}
269 	set_bit(QUEUE_FLAG_CLUSTER, &new->queue->queue_flags);
270 
271 	blk_queue_make_request(new->queue, md_fail_request);
272 
273 	goto retry;
274 }
275 
276 static inline int mddev_lock(mddev_t * mddev)
277 {
278 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
279 }
280 
281 static inline void mddev_lock_uninterruptible(mddev_t * mddev)
282 {
283 	mutex_lock(&mddev->reconfig_mutex);
284 }
285 
286 static inline int mddev_trylock(mddev_t * mddev)
287 {
288 	return mutex_trylock(&mddev->reconfig_mutex);
289 }
290 
291 static inline void mddev_unlock(mddev_t * mddev)
292 {
293 	mutex_unlock(&mddev->reconfig_mutex);
294 
295 	md_wakeup_thread(mddev->thread);
296 }
297 
298 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
299 {
300 	mdk_rdev_t * rdev;
301 	struct list_head *tmp;
302 
303 	ITERATE_RDEV(mddev,rdev,tmp) {
304 		if (rdev->desc_nr == nr)
305 			return rdev;
306 	}
307 	return NULL;
308 }
309 
310 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
311 {
312 	struct list_head *tmp;
313 	mdk_rdev_t *rdev;
314 
315 	ITERATE_RDEV(mddev,rdev,tmp) {
316 		if (rdev->bdev->bd_dev == dev)
317 			return rdev;
318 	}
319 	return NULL;
320 }
321 
322 static struct mdk_personality *find_pers(int level, char *clevel)
323 {
324 	struct mdk_personality *pers;
325 	list_for_each_entry(pers, &pers_list, list) {
326 		if (level != LEVEL_NONE && pers->level == level)
327 			return pers;
328 		if (strcmp(pers->name, clevel)==0)
329 			return pers;
330 	}
331 	return NULL;
332 }
333 
334 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
335 {
336 	sector_t size = bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
337 	return MD_NEW_SIZE_BLOCKS(size);
338 }
339 
340 static sector_t calc_dev_size(mdk_rdev_t *rdev, unsigned chunk_size)
341 {
342 	sector_t size;
343 
344 	size = rdev->sb_offset;
345 
346 	if (chunk_size)
347 		size &= ~((sector_t)chunk_size/1024 - 1);
348 	return size;
349 }
350 
351 static int alloc_disk_sb(mdk_rdev_t * rdev)
352 {
353 	if (rdev->sb_page)
354 		MD_BUG();
355 
356 	rdev->sb_page = alloc_page(GFP_KERNEL);
357 	if (!rdev->sb_page) {
358 		printk(KERN_ALERT "md: out of memory.\n");
359 		return -EINVAL;
360 	}
361 
362 	return 0;
363 }
364 
365 static void free_disk_sb(mdk_rdev_t * rdev)
366 {
367 	if (rdev->sb_page) {
368 		put_page(rdev->sb_page);
369 		rdev->sb_loaded = 0;
370 		rdev->sb_page = NULL;
371 		rdev->sb_offset = 0;
372 		rdev->size = 0;
373 	}
374 }
375 
376 
377 static int super_written(struct bio *bio, unsigned int bytes_done, int error)
378 {
379 	mdk_rdev_t *rdev = bio->bi_private;
380 	mddev_t *mddev = rdev->mddev;
381 	if (bio->bi_size)
382 		return 1;
383 
384 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags))
385 		md_error(mddev, rdev);
386 
387 	if (atomic_dec_and_test(&mddev->pending_writes))
388 		wake_up(&mddev->sb_wait);
389 	bio_put(bio);
390 	return 0;
391 }
392 
393 static int super_written_barrier(struct bio *bio, unsigned int bytes_done, int error)
394 {
395 	struct bio *bio2 = bio->bi_private;
396 	mdk_rdev_t *rdev = bio2->bi_private;
397 	mddev_t *mddev = rdev->mddev;
398 	if (bio->bi_size)
399 		return 1;
400 
401 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
402 	    error == -EOPNOTSUPP) {
403 		unsigned long flags;
404 		/* barriers don't appear to be supported :-( */
405 		set_bit(BarriersNotsupp, &rdev->flags);
406 		mddev->barriers_work = 0;
407 		spin_lock_irqsave(&mddev->write_lock, flags);
408 		bio2->bi_next = mddev->biolist;
409 		mddev->biolist = bio2;
410 		spin_unlock_irqrestore(&mddev->write_lock, flags);
411 		wake_up(&mddev->sb_wait);
412 		bio_put(bio);
413 		return 0;
414 	}
415 	bio_put(bio2);
416 	bio->bi_private = rdev;
417 	return super_written(bio, bytes_done, error);
418 }
419 
420 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
421 		   sector_t sector, int size, struct page *page)
422 {
423 	/* write first size bytes of page to sector of rdev
424 	 * Increment mddev->pending_writes before returning
425 	 * and decrement it on completion, waking up sb_wait
426 	 * if zero is reached.
427 	 * If an error occurred, call md_error
428 	 *
429 	 * As we might need to resubmit the request if BIO_RW_BARRIER
430 	 * causes ENOTSUPP, we allocate a spare bio...
431 	 */
432 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
433 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNC);
434 
435 	bio->bi_bdev = rdev->bdev;
436 	bio->bi_sector = sector;
437 	bio_add_page(bio, page, size, 0);
438 	bio->bi_private = rdev;
439 	bio->bi_end_io = super_written;
440 	bio->bi_rw = rw;
441 
442 	atomic_inc(&mddev->pending_writes);
443 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
444 		struct bio *rbio;
445 		rw |= (1<<BIO_RW_BARRIER);
446 		rbio = bio_clone(bio, GFP_NOIO);
447 		rbio->bi_private = bio;
448 		rbio->bi_end_io = super_written_barrier;
449 		submit_bio(rw, rbio);
450 	} else
451 		submit_bio(rw, bio);
452 }
453 
454 void md_super_wait(mddev_t *mddev)
455 {
456 	/* wait for all superblock writes that were scheduled to complete.
457 	 * if any had to be retried (due to BARRIER problems), retry them
458 	 */
459 	DEFINE_WAIT(wq);
460 	for(;;) {
461 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
462 		if (atomic_read(&mddev->pending_writes)==0)
463 			break;
464 		while (mddev->biolist) {
465 			struct bio *bio;
466 			spin_lock_irq(&mddev->write_lock);
467 			bio = mddev->biolist;
468 			mddev->biolist = bio->bi_next ;
469 			bio->bi_next = NULL;
470 			spin_unlock_irq(&mddev->write_lock);
471 			submit_bio(bio->bi_rw, bio);
472 		}
473 		schedule();
474 	}
475 	finish_wait(&mddev->sb_wait, &wq);
476 }
477 
478 static int bi_complete(struct bio *bio, unsigned int bytes_done, int error)
479 {
480 	if (bio->bi_size)
481 		return 1;
482 
483 	complete((struct completion*)bio->bi_private);
484 	return 0;
485 }
486 
487 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
488 		   struct page *page, int rw)
489 {
490 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
491 	struct completion event;
492 	int ret;
493 
494 	rw |= (1 << BIO_RW_SYNC);
495 
496 	bio->bi_bdev = bdev;
497 	bio->bi_sector = sector;
498 	bio_add_page(bio, page, size, 0);
499 	init_completion(&event);
500 	bio->bi_private = &event;
501 	bio->bi_end_io = bi_complete;
502 	submit_bio(rw, bio);
503 	wait_for_completion(&event);
504 
505 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
506 	bio_put(bio);
507 	return ret;
508 }
509 EXPORT_SYMBOL_GPL(sync_page_io);
510 
511 static int read_disk_sb(mdk_rdev_t * rdev, int size)
512 {
513 	char b[BDEVNAME_SIZE];
514 	if (!rdev->sb_page) {
515 		MD_BUG();
516 		return -EINVAL;
517 	}
518 	if (rdev->sb_loaded)
519 		return 0;
520 
521 
522 	if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, size, rdev->sb_page, READ))
523 		goto fail;
524 	rdev->sb_loaded = 1;
525 	return 0;
526 
527 fail:
528 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
529 		bdevname(rdev->bdev,b));
530 	return -EINVAL;
531 }
532 
533 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
534 {
535 	if (	(sb1->set_uuid0 == sb2->set_uuid0) &&
536 		(sb1->set_uuid1 == sb2->set_uuid1) &&
537 		(sb1->set_uuid2 == sb2->set_uuid2) &&
538 		(sb1->set_uuid3 == sb2->set_uuid3))
539 
540 		return 1;
541 
542 	return 0;
543 }
544 
545 
546 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
547 {
548 	int ret;
549 	mdp_super_t *tmp1, *tmp2;
550 
551 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
552 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
553 
554 	if (!tmp1 || !tmp2) {
555 		ret = 0;
556 		printk(KERN_INFO "md.c: sb1 is not equal to sb2!\n");
557 		goto abort;
558 	}
559 
560 	*tmp1 = *sb1;
561 	*tmp2 = *sb2;
562 
563 	/*
564 	 * nr_disks is not constant
565 	 */
566 	tmp1->nr_disks = 0;
567 	tmp2->nr_disks = 0;
568 
569 	if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
570 		ret = 0;
571 	else
572 		ret = 1;
573 
574 abort:
575 	kfree(tmp1);
576 	kfree(tmp2);
577 	return ret;
578 }
579 
580 static unsigned int calc_sb_csum(mdp_super_t * sb)
581 {
582 	unsigned int disk_csum, csum;
583 
584 	disk_csum = sb->sb_csum;
585 	sb->sb_csum = 0;
586 	csum = csum_partial((void *)sb, MD_SB_BYTES, 0);
587 	sb->sb_csum = disk_csum;
588 	return csum;
589 }
590 
591 
592 /*
593  * Handle superblock details.
594  * We want to be able to handle multiple superblock formats
595  * so we have a common interface to them all, and an array of
596  * different handlers.
597  * We rely on user-space to write the initial superblock, and support
598  * reading and updating of superblocks.
599  * Interface methods are:
600  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
601  *      loads and validates a superblock on dev.
602  *      if refdev != NULL, compare superblocks on both devices
603  *    Return:
604  *      0 - dev has a superblock that is compatible with refdev
605  *      1 - dev has a superblock that is compatible and newer than refdev
606  *          so dev should be used as the refdev in future
607  *     -EINVAL superblock incompatible or invalid
608  *     -othererror e.g. -EIO
609  *
610  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
611  *      Verify that dev is acceptable into mddev.
612  *       The first time, mddev->raid_disks will be 0, and data from
613  *       dev should be merged in.  Subsequent calls check that dev
614  *       is new enough.  Return 0 or -EINVAL
615  *
616  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
617  *     Update the superblock for rdev with data in mddev
618  *     This does not write to disc.
619  *
620  */
621 
622 struct super_type  {
623 	char 		*name;
624 	struct module	*owner;
625 	int		(*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version);
626 	int		(*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
627 	void		(*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
628 };
629 
630 /*
631  * load_super for 0.90.0
632  */
633 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
634 {
635 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
636 	mdp_super_t *sb;
637 	int ret;
638 	sector_t sb_offset;
639 
640 	/*
641 	 * Calculate the position of the superblock,
642 	 * it's at the end of the disk.
643 	 *
644 	 * It also happens to be a multiple of 4Kb.
645 	 */
646 	sb_offset = calc_dev_sboffset(rdev->bdev);
647 	rdev->sb_offset = sb_offset;
648 
649 	ret = read_disk_sb(rdev, MD_SB_BYTES);
650 	if (ret) return ret;
651 
652 	ret = -EINVAL;
653 
654 	bdevname(rdev->bdev, b);
655 	sb = (mdp_super_t*)page_address(rdev->sb_page);
656 
657 	if (sb->md_magic != MD_SB_MAGIC) {
658 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
659 		       b);
660 		goto abort;
661 	}
662 
663 	if (sb->major_version != 0 ||
664 	    sb->minor_version < 90 ||
665 	    sb->minor_version > 91) {
666 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
667 			sb->major_version, sb->minor_version,
668 			b);
669 		goto abort;
670 	}
671 
672 	if (sb->raid_disks <= 0)
673 		goto abort;
674 
675 	if (csum_fold(calc_sb_csum(sb)) != csum_fold(sb->sb_csum)) {
676 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
677 			b);
678 		goto abort;
679 	}
680 
681 	rdev->preferred_minor = sb->md_minor;
682 	rdev->data_offset = 0;
683 	rdev->sb_size = MD_SB_BYTES;
684 
685 	if (sb->level == LEVEL_MULTIPATH)
686 		rdev->desc_nr = -1;
687 	else
688 		rdev->desc_nr = sb->this_disk.number;
689 
690 	if (refdev == 0)
691 		ret = 1;
692 	else {
693 		__u64 ev1, ev2;
694 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
695 		if (!uuid_equal(refsb, sb)) {
696 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
697 				b, bdevname(refdev->bdev,b2));
698 			goto abort;
699 		}
700 		if (!sb_equal(refsb, sb)) {
701 			printk(KERN_WARNING "md: %s has same UUID"
702 			       " but different superblock to %s\n",
703 			       b, bdevname(refdev->bdev, b2));
704 			goto abort;
705 		}
706 		ev1 = md_event(sb);
707 		ev2 = md_event(refsb);
708 		if (ev1 > ev2)
709 			ret = 1;
710 		else
711 			ret = 0;
712 	}
713 	rdev->size = calc_dev_size(rdev, sb->chunk_size);
714 
715 	if (rdev->size < sb->size && sb->level > 1)
716 		/* "this cannot possibly happen" ... */
717 		ret = -EINVAL;
718 
719  abort:
720 	return ret;
721 }
722 
723 /*
724  * validate_super for 0.90.0
725  */
726 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
727 {
728 	mdp_disk_t *desc;
729 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
730 
731 	rdev->raid_disk = -1;
732 	rdev->flags = 0;
733 	if (mddev->raid_disks == 0) {
734 		mddev->major_version = 0;
735 		mddev->minor_version = sb->minor_version;
736 		mddev->patch_version = sb->patch_version;
737 		mddev->persistent = ! sb->not_persistent;
738 		mddev->chunk_size = sb->chunk_size;
739 		mddev->ctime = sb->ctime;
740 		mddev->utime = sb->utime;
741 		mddev->level = sb->level;
742 		mddev->clevel[0] = 0;
743 		mddev->layout = sb->layout;
744 		mddev->raid_disks = sb->raid_disks;
745 		mddev->size = sb->size;
746 		mddev->events = md_event(sb);
747 		mddev->bitmap_offset = 0;
748 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
749 
750 		if (mddev->minor_version >= 91) {
751 			mddev->reshape_position = sb->reshape_position;
752 			mddev->delta_disks = sb->delta_disks;
753 			mddev->new_level = sb->new_level;
754 			mddev->new_layout = sb->new_layout;
755 			mddev->new_chunk = sb->new_chunk;
756 		} else {
757 			mddev->reshape_position = MaxSector;
758 			mddev->delta_disks = 0;
759 			mddev->new_level = mddev->level;
760 			mddev->new_layout = mddev->layout;
761 			mddev->new_chunk = mddev->chunk_size;
762 		}
763 
764 		if (sb->state & (1<<MD_SB_CLEAN))
765 			mddev->recovery_cp = MaxSector;
766 		else {
767 			if (sb->events_hi == sb->cp_events_hi &&
768 				sb->events_lo == sb->cp_events_lo) {
769 				mddev->recovery_cp = sb->recovery_cp;
770 			} else
771 				mddev->recovery_cp = 0;
772 		}
773 
774 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
775 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
776 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
777 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
778 
779 		mddev->max_disks = MD_SB_DISKS;
780 
781 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
782 		    mddev->bitmap_file == NULL) {
783 			if (mddev->level != 1 && mddev->level != 4
784 			    && mddev->level != 5 && mddev->level != 6
785 			    && mddev->level != 10) {
786 				/* FIXME use a better test */
787 				printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
788 				return -EINVAL;
789 			}
790 			mddev->bitmap_offset = mddev->default_bitmap_offset;
791 		}
792 
793 	} else if (mddev->pers == NULL) {
794 		/* Insist on good event counter while assembling */
795 		__u64 ev1 = md_event(sb);
796 		++ev1;
797 		if (ev1 < mddev->events)
798 			return -EINVAL;
799 	} else if (mddev->bitmap) {
800 		/* if adding to array with a bitmap, then we can accept an
801 		 * older device ... but not too old.
802 		 */
803 		__u64 ev1 = md_event(sb);
804 		if (ev1 < mddev->bitmap->events_cleared)
805 			return 0;
806 	} else /* just a hot-add of a new device, leave raid_disk at -1 */
807 		return 0;
808 
809 	if (mddev->level != LEVEL_MULTIPATH) {
810 		desc = sb->disks + rdev->desc_nr;
811 
812 		if (desc->state & (1<<MD_DISK_FAULTY))
813 			set_bit(Faulty, &rdev->flags);
814 		else if (desc->state & (1<<MD_DISK_SYNC) &&
815 			 desc->raid_disk < mddev->raid_disks) {
816 			set_bit(In_sync, &rdev->flags);
817 			rdev->raid_disk = desc->raid_disk;
818 		}
819 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
820 			set_bit(WriteMostly, &rdev->flags);
821 	} else /* MULTIPATH are always insync */
822 		set_bit(In_sync, &rdev->flags);
823 	return 0;
824 }
825 
826 /*
827  * sync_super for 0.90.0
828  */
829 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
830 {
831 	mdp_super_t *sb;
832 	struct list_head *tmp;
833 	mdk_rdev_t *rdev2;
834 	int next_spare = mddev->raid_disks;
835 
836 
837 	/* make rdev->sb match mddev data..
838 	 *
839 	 * 1/ zero out disks
840 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
841 	 * 3/ any empty disks < next_spare become removed
842 	 *
843 	 * disks[0] gets initialised to REMOVED because
844 	 * we cannot be sure from other fields if it has
845 	 * been initialised or not.
846 	 */
847 	int i;
848 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
849 
850 	rdev->sb_size = MD_SB_BYTES;
851 
852 	sb = (mdp_super_t*)page_address(rdev->sb_page);
853 
854 	memset(sb, 0, sizeof(*sb));
855 
856 	sb->md_magic = MD_SB_MAGIC;
857 	sb->major_version = mddev->major_version;
858 	sb->patch_version = mddev->patch_version;
859 	sb->gvalid_words  = 0; /* ignored */
860 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
861 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
862 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
863 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
864 
865 	sb->ctime = mddev->ctime;
866 	sb->level = mddev->level;
867 	sb->size  = mddev->size;
868 	sb->raid_disks = mddev->raid_disks;
869 	sb->md_minor = mddev->md_minor;
870 	sb->not_persistent = !mddev->persistent;
871 	sb->utime = mddev->utime;
872 	sb->state = 0;
873 	sb->events_hi = (mddev->events>>32);
874 	sb->events_lo = (u32)mddev->events;
875 
876 	if (mddev->reshape_position == MaxSector)
877 		sb->minor_version = 90;
878 	else {
879 		sb->minor_version = 91;
880 		sb->reshape_position = mddev->reshape_position;
881 		sb->new_level = mddev->new_level;
882 		sb->delta_disks = mddev->delta_disks;
883 		sb->new_layout = mddev->new_layout;
884 		sb->new_chunk = mddev->new_chunk;
885 	}
886 	mddev->minor_version = sb->minor_version;
887 	if (mddev->in_sync)
888 	{
889 		sb->recovery_cp = mddev->recovery_cp;
890 		sb->cp_events_hi = (mddev->events>>32);
891 		sb->cp_events_lo = (u32)mddev->events;
892 		if (mddev->recovery_cp == MaxSector)
893 			sb->state = (1<< MD_SB_CLEAN);
894 	} else
895 		sb->recovery_cp = 0;
896 
897 	sb->layout = mddev->layout;
898 	sb->chunk_size = mddev->chunk_size;
899 
900 	if (mddev->bitmap && mddev->bitmap_file == NULL)
901 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
902 
903 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
904 	ITERATE_RDEV(mddev,rdev2,tmp) {
905 		mdp_disk_t *d;
906 		int desc_nr;
907 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
908 		    && !test_bit(Faulty, &rdev2->flags))
909 			desc_nr = rdev2->raid_disk;
910 		else
911 			desc_nr = next_spare++;
912 		rdev2->desc_nr = desc_nr;
913 		d = &sb->disks[rdev2->desc_nr];
914 		nr_disks++;
915 		d->number = rdev2->desc_nr;
916 		d->major = MAJOR(rdev2->bdev->bd_dev);
917 		d->minor = MINOR(rdev2->bdev->bd_dev);
918 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
919 		    && !test_bit(Faulty, &rdev2->flags))
920 			d->raid_disk = rdev2->raid_disk;
921 		else
922 			d->raid_disk = rdev2->desc_nr; /* compatibility */
923 		if (test_bit(Faulty, &rdev2->flags))
924 			d->state = (1<<MD_DISK_FAULTY);
925 		else if (test_bit(In_sync, &rdev2->flags)) {
926 			d->state = (1<<MD_DISK_ACTIVE);
927 			d->state |= (1<<MD_DISK_SYNC);
928 			active++;
929 			working++;
930 		} else {
931 			d->state = 0;
932 			spare++;
933 			working++;
934 		}
935 		if (test_bit(WriteMostly, &rdev2->flags))
936 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
937 	}
938 	/* now set the "removed" and "faulty" bits on any missing devices */
939 	for (i=0 ; i < mddev->raid_disks ; i++) {
940 		mdp_disk_t *d = &sb->disks[i];
941 		if (d->state == 0 && d->number == 0) {
942 			d->number = i;
943 			d->raid_disk = i;
944 			d->state = (1<<MD_DISK_REMOVED);
945 			d->state |= (1<<MD_DISK_FAULTY);
946 			failed++;
947 		}
948 	}
949 	sb->nr_disks = nr_disks;
950 	sb->active_disks = active;
951 	sb->working_disks = working;
952 	sb->failed_disks = failed;
953 	sb->spare_disks = spare;
954 
955 	sb->this_disk = sb->disks[rdev->desc_nr];
956 	sb->sb_csum = calc_sb_csum(sb);
957 }
958 
959 /*
960  * version 1 superblock
961  */
962 
963 static unsigned int calc_sb_1_csum(struct mdp_superblock_1 * sb)
964 {
965 	unsigned int disk_csum, csum;
966 	unsigned long long newcsum;
967 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
968 	unsigned int *isuper = (unsigned int*)sb;
969 	int i;
970 
971 	disk_csum = sb->sb_csum;
972 	sb->sb_csum = 0;
973 	newcsum = 0;
974 	for (i=0; size>=4; size -= 4 )
975 		newcsum += le32_to_cpu(*isuper++);
976 
977 	if (size == 2)
978 		newcsum += le16_to_cpu(*(unsigned short*) isuper);
979 
980 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
981 	sb->sb_csum = disk_csum;
982 	return cpu_to_le32(csum);
983 }
984 
985 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
986 {
987 	struct mdp_superblock_1 *sb;
988 	int ret;
989 	sector_t sb_offset;
990 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
991 	int bmask;
992 
993 	/*
994 	 * Calculate the position of the superblock.
995 	 * It is always aligned to a 4K boundary and
996 	 * depeding on minor_version, it can be:
997 	 * 0: At least 8K, but less than 12K, from end of device
998 	 * 1: At start of device
999 	 * 2: 4K from start of device.
1000 	 */
1001 	switch(minor_version) {
1002 	case 0:
1003 		sb_offset = rdev->bdev->bd_inode->i_size >> 9;
1004 		sb_offset -= 8*2;
1005 		sb_offset &= ~(sector_t)(4*2-1);
1006 		/* convert from sectors to K */
1007 		sb_offset /= 2;
1008 		break;
1009 	case 1:
1010 		sb_offset = 0;
1011 		break;
1012 	case 2:
1013 		sb_offset = 4;
1014 		break;
1015 	default:
1016 		return -EINVAL;
1017 	}
1018 	rdev->sb_offset = sb_offset;
1019 
1020 	/* superblock is rarely larger than 1K, but it can be larger,
1021 	 * and it is safe to read 4k, so we do that
1022 	 */
1023 	ret = read_disk_sb(rdev, 4096);
1024 	if (ret) return ret;
1025 
1026 
1027 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1028 
1029 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1030 	    sb->major_version != cpu_to_le32(1) ||
1031 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1032 	    le64_to_cpu(sb->super_offset) != (rdev->sb_offset<<1) ||
1033 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1034 		return -EINVAL;
1035 
1036 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1037 		printk("md: invalid superblock checksum on %s\n",
1038 			bdevname(rdev->bdev,b));
1039 		return -EINVAL;
1040 	}
1041 	if (le64_to_cpu(sb->data_size) < 10) {
1042 		printk("md: data_size too small on %s\n",
1043 		       bdevname(rdev->bdev,b));
1044 		return -EINVAL;
1045 	}
1046 	rdev->preferred_minor = 0xffff;
1047 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1048 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1049 
1050 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1051 	bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
1052 	if (rdev->sb_size & bmask)
1053 		rdev-> sb_size = (rdev->sb_size | bmask)+1;
1054 
1055 	if (refdev == 0)
1056 		ret = 1;
1057 	else {
1058 		__u64 ev1, ev2;
1059 		struct mdp_superblock_1 *refsb =
1060 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1061 
1062 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1063 		    sb->level != refsb->level ||
1064 		    sb->layout != refsb->layout ||
1065 		    sb->chunksize != refsb->chunksize) {
1066 			printk(KERN_WARNING "md: %s has strangely different"
1067 				" superblock to %s\n",
1068 				bdevname(rdev->bdev,b),
1069 				bdevname(refdev->bdev,b2));
1070 			return -EINVAL;
1071 		}
1072 		ev1 = le64_to_cpu(sb->events);
1073 		ev2 = le64_to_cpu(refsb->events);
1074 
1075 		if (ev1 > ev2)
1076 			ret = 1;
1077 		else
1078 			ret = 0;
1079 	}
1080 	if (minor_version)
1081 		rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
1082 	else
1083 		rdev->size = rdev->sb_offset;
1084 	if (rdev->size < le64_to_cpu(sb->data_size)/2)
1085 		return -EINVAL;
1086 	rdev->size = le64_to_cpu(sb->data_size)/2;
1087 	if (le32_to_cpu(sb->chunksize))
1088 		rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
1089 
1090 	if (le32_to_cpu(sb->size) > rdev->size*2)
1091 		return -EINVAL;
1092 	return ret;
1093 }
1094 
1095 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1096 {
1097 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1098 
1099 	rdev->raid_disk = -1;
1100 	rdev->flags = 0;
1101 	if (mddev->raid_disks == 0) {
1102 		mddev->major_version = 1;
1103 		mddev->patch_version = 0;
1104 		mddev->persistent = 1;
1105 		mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
1106 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1107 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1108 		mddev->level = le32_to_cpu(sb->level);
1109 		mddev->clevel[0] = 0;
1110 		mddev->layout = le32_to_cpu(sb->layout);
1111 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1112 		mddev->size = le64_to_cpu(sb->size)/2;
1113 		mddev->events = le64_to_cpu(sb->events);
1114 		mddev->bitmap_offset = 0;
1115 		mddev->default_bitmap_offset = 1024 >> 9;
1116 
1117 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1118 		memcpy(mddev->uuid, sb->set_uuid, 16);
1119 
1120 		mddev->max_disks =  (4096-256)/2;
1121 
1122 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1123 		    mddev->bitmap_file == NULL ) {
1124 			if (mddev->level != 1 && mddev->level != 5 && mddev->level != 6
1125 			    && mddev->level != 10) {
1126 				printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
1127 				return -EINVAL;
1128 			}
1129 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1130 		}
1131 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1132 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1133 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1134 			mddev->new_level = le32_to_cpu(sb->new_level);
1135 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1136 			mddev->new_chunk = le32_to_cpu(sb->new_chunk)<<9;
1137 		} else {
1138 			mddev->reshape_position = MaxSector;
1139 			mddev->delta_disks = 0;
1140 			mddev->new_level = mddev->level;
1141 			mddev->new_layout = mddev->layout;
1142 			mddev->new_chunk = mddev->chunk_size;
1143 		}
1144 
1145 	} else if (mddev->pers == NULL) {
1146 		/* Insist of good event counter while assembling */
1147 		__u64 ev1 = le64_to_cpu(sb->events);
1148 		++ev1;
1149 		if (ev1 < mddev->events)
1150 			return -EINVAL;
1151 	} else if (mddev->bitmap) {
1152 		/* If adding to array with a bitmap, then we can accept an
1153 		 * older device, but not too old.
1154 		 */
1155 		__u64 ev1 = le64_to_cpu(sb->events);
1156 		if (ev1 < mddev->bitmap->events_cleared)
1157 			return 0;
1158 	} else /* just a hot-add of a new device, leave raid_disk at -1 */
1159 		return 0;
1160 
1161 	if (mddev->level != LEVEL_MULTIPATH) {
1162 		int role;
1163 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1164 		role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1165 		switch(role) {
1166 		case 0xffff: /* spare */
1167 			break;
1168 		case 0xfffe: /* faulty */
1169 			set_bit(Faulty, &rdev->flags);
1170 			break;
1171 		default:
1172 			set_bit(In_sync, &rdev->flags);
1173 			rdev->raid_disk = role;
1174 			break;
1175 		}
1176 		if (sb->devflags & WriteMostly1)
1177 			set_bit(WriteMostly, &rdev->flags);
1178 	} else /* MULTIPATH are always insync */
1179 		set_bit(In_sync, &rdev->flags);
1180 
1181 	return 0;
1182 }
1183 
1184 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1185 {
1186 	struct mdp_superblock_1 *sb;
1187 	struct list_head *tmp;
1188 	mdk_rdev_t *rdev2;
1189 	int max_dev, i;
1190 	/* make rdev->sb match mddev and rdev data. */
1191 
1192 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1193 
1194 	sb->feature_map = 0;
1195 	sb->pad0 = 0;
1196 	memset(sb->pad1, 0, sizeof(sb->pad1));
1197 	memset(sb->pad2, 0, sizeof(sb->pad2));
1198 	memset(sb->pad3, 0, sizeof(sb->pad3));
1199 
1200 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1201 	sb->events = cpu_to_le64(mddev->events);
1202 	if (mddev->in_sync)
1203 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1204 	else
1205 		sb->resync_offset = cpu_to_le64(0);
1206 
1207 	sb->cnt_corrected_read = atomic_read(&rdev->corrected_errors);
1208 
1209 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1210 	sb->size = cpu_to_le64(mddev->size<<1);
1211 
1212 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1213 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1214 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1215 	}
1216 	if (mddev->reshape_position != MaxSector) {
1217 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1218 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1219 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1220 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1221 		sb->new_level = cpu_to_le32(mddev->new_level);
1222 		sb->new_chunk = cpu_to_le32(mddev->new_chunk>>9);
1223 	}
1224 
1225 	max_dev = 0;
1226 	ITERATE_RDEV(mddev,rdev2,tmp)
1227 		if (rdev2->desc_nr+1 > max_dev)
1228 			max_dev = rdev2->desc_nr+1;
1229 
1230 	sb->max_dev = cpu_to_le32(max_dev);
1231 	for (i=0; i<max_dev;i++)
1232 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1233 
1234 	ITERATE_RDEV(mddev,rdev2,tmp) {
1235 		i = rdev2->desc_nr;
1236 		if (test_bit(Faulty, &rdev2->flags))
1237 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1238 		else if (test_bit(In_sync, &rdev2->flags))
1239 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1240 		else
1241 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1242 	}
1243 
1244 	sb->recovery_offset = cpu_to_le64(0); /* not supported yet */
1245 	sb->sb_csum = calc_sb_1_csum(sb);
1246 }
1247 
1248 
1249 static struct super_type super_types[] = {
1250 	[0] = {
1251 		.name	= "0.90.0",
1252 		.owner	= THIS_MODULE,
1253 		.load_super	= super_90_load,
1254 		.validate_super	= super_90_validate,
1255 		.sync_super	= super_90_sync,
1256 	},
1257 	[1] = {
1258 		.name	= "md-1",
1259 		.owner	= THIS_MODULE,
1260 		.load_super	= super_1_load,
1261 		.validate_super	= super_1_validate,
1262 		.sync_super	= super_1_sync,
1263 	},
1264 };
1265 
1266 static mdk_rdev_t * match_dev_unit(mddev_t *mddev, mdk_rdev_t *dev)
1267 {
1268 	struct list_head *tmp;
1269 	mdk_rdev_t *rdev;
1270 
1271 	ITERATE_RDEV(mddev,rdev,tmp)
1272 		if (rdev->bdev->bd_contains == dev->bdev->bd_contains)
1273 			return rdev;
1274 
1275 	return NULL;
1276 }
1277 
1278 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1279 {
1280 	struct list_head *tmp;
1281 	mdk_rdev_t *rdev;
1282 
1283 	ITERATE_RDEV(mddev1,rdev,tmp)
1284 		if (match_dev_unit(mddev2, rdev))
1285 			return 1;
1286 
1287 	return 0;
1288 }
1289 
1290 static LIST_HEAD(pending_raid_disks);
1291 
1292 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1293 {
1294 	mdk_rdev_t *same_pdev;
1295 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1296 	struct kobject *ko;
1297 	char *s;
1298 
1299 	if (rdev->mddev) {
1300 		MD_BUG();
1301 		return -EINVAL;
1302 	}
1303 	/* make sure rdev->size exceeds mddev->size */
1304 	if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
1305 		if (mddev->pers)
1306 			/* Cannot change size, so fail */
1307 			return -ENOSPC;
1308 		else
1309 			mddev->size = rdev->size;
1310 	}
1311 	same_pdev = match_dev_unit(mddev, rdev);
1312 	if (same_pdev)
1313 		printk(KERN_WARNING
1314 			"%s: WARNING: %s appears to be on the same physical"
1315 	 		" disk as %s. True\n     protection against single-disk"
1316 			" failure might be compromised.\n",
1317 			mdname(mddev), bdevname(rdev->bdev,b),
1318 			bdevname(same_pdev->bdev,b2));
1319 
1320 	/* Verify rdev->desc_nr is unique.
1321 	 * If it is -1, assign a free number, else
1322 	 * check number is not in use
1323 	 */
1324 	if (rdev->desc_nr < 0) {
1325 		int choice = 0;
1326 		if (mddev->pers) choice = mddev->raid_disks;
1327 		while (find_rdev_nr(mddev, choice))
1328 			choice++;
1329 		rdev->desc_nr = choice;
1330 	} else {
1331 		if (find_rdev_nr(mddev, rdev->desc_nr))
1332 			return -EBUSY;
1333 	}
1334 	bdevname(rdev->bdev,b);
1335 	if (kobject_set_name(&rdev->kobj, "dev-%s", b) < 0)
1336 		return -ENOMEM;
1337 	while ( (s=strchr(rdev->kobj.k_name, '/')) != NULL)
1338 		*s = '!';
1339 
1340 	list_add(&rdev->same_set, &mddev->disks);
1341 	rdev->mddev = mddev;
1342 	printk(KERN_INFO "md: bind<%s>\n", b);
1343 
1344 	rdev->kobj.parent = &mddev->kobj;
1345 	kobject_add(&rdev->kobj);
1346 
1347 	if (rdev->bdev->bd_part)
1348 		ko = &rdev->bdev->bd_part->kobj;
1349 	else
1350 		ko = &rdev->bdev->bd_disk->kobj;
1351 	sysfs_create_link(&rdev->kobj, ko, "block");
1352 	bd_claim_by_disk(rdev->bdev, rdev, mddev->gendisk);
1353 	return 0;
1354 }
1355 
1356 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1357 {
1358 	char b[BDEVNAME_SIZE];
1359 	if (!rdev->mddev) {
1360 		MD_BUG();
1361 		return;
1362 	}
1363 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1364 	list_del_init(&rdev->same_set);
1365 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1366 	rdev->mddev = NULL;
1367 	sysfs_remove_link(&rdev->kobj, "block");
1368 	kobject_del(&rdev->kobj);
1369 }
1370 
1371 /*
1372  * prevent the device from being mounted, repartitioned or
1373  * otherwise reused by a RAID array (or any other kernel
1374  * subsystem), by bd_claiming the device.
1375  */
1376 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev)
1377 {
1378 	int err = 0;
1379 	struct block_device *bdev;
1380 	char b[BDEVNAME_SIZE];
1381 
1382 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1383 	if (IS_ERR(bdev)) {
1384 		printk(KERN_ERR "md: could not open %s.\n",
1385 			__bdevname(dev, b));
1386 		return PTR_ERR(bdev);
1387 	}
1388 	err = bd_claim(bdev, rdev);
1389 	if (err) {
1390 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1391 			bdevname(bdev, b));
1392 		blkdev_put(bdev);
1393 		return err;
1394 	}
1395 	rdev->bdev = bdev;
1396 	return err;
1397 }
1398 
1399 static void unlock_rdev(mdk_rdev_t *rdev)
1400 {
1401 	struct block_device *bdev = rdev->bdev;
1402 	rdev->bdev = NULL;
1403 	if (!bdev)
1404 		MD_BUG();
1405 	bd_release(bdev);
1406 	blkdev_put(bdev);
1407 }
1408 
1409 void md_autodetect_dev(dev_t dev);
1410 
1411 static void export_rdev(mdk_rdev_t * rdev)
1412 {
1413 	char b[BDEVNAME_SIZE];
1414 	printk(KERN_INFO "md: export_rdev(%s)\n",
1415 		bdevname(rdev->bdev,b));
1416 	if (rdev->mddev)
1417 		MD_BUG();
1418 	free_disk_sb(rdev);
1419 	list_del_init(&rdev->same_set);
1420 #ifndef MODULE
1421 	md_autodetect_dev(rdev->bdev->bd_dev);
1422 #endif
1423 	unlock_rdev(rdev);
1424 	kobject_put(&rdev->kobj);
1425 }
1426 
1427 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1428 {
1429 	unbind_rdev_from_array(rdev);
1430 	export_rdev(rdev);
1431 }
1432 
1433 static void export_array(mddev_t *mddev)
1434 {
1435 	struct list_head *tmp;
1436 	mdk_rdev_t *rdev;
1437 
1438 	ITERATE_RDEV(mddev,rdev,tmp) {
1439 		if (!rdev->mddev) {
1440 			MD_BUG();
1441 			continue;
1442 		}
1443 		kick_rdev_from_array(rdev);
1444 	}
1445 	if (!list_empty(&mddev->disks))
1446 		MD_BUG();
1447 	mddev->raid_disks = 0;
1448 	mddev->major_version = 0;
1449 }
1450 
1451 static void print_desc(mdp_disk_t *desc)
1452 {
1453 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1454 		desc->major,desc->minor,desc->raid_disk,desc->state);
1455 }
1456 
1457 static void print_sb(mdp_super_t *sb)
1458 {
1459 	int i;
1460 
1461 	printk(KERN_INFO
1462 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1463 		sb->major_version, sb->minor_version, sb->patch_version,
1464 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1465 		sb->ctime);
1466 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1467 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1468 		sb->md_minor, sb->layout, sb->chunk_size);
1469 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1470 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1471 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1472 		sb->failed_disks, sb->spare_disks,
1473 		sb->sb_csum, (unsigned long)sb->events_lo);
1474 
1475 	printk(KERN_INFO);
1476 	for (i = 0; i < MD_SB_DISKS; i++) {
1477 		mdp_disk_t *desc;
1478 
1479 		desc = sb->disks + i;
1480 		if (desc->number || desc->major || desc->minor ||
1481 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1482 			printk("     D %2d: ", i);
1483 			print_desc(desc);
1484 		}
1485 	}
1486 	printk(KERN_INFO "md:     THIS: ");
1487 	print_desc(&sb->this_disk);
1488 
1489 }
1490 
1491 static void print_rdev(mdk_rdev_t *rdev)
1492 {
1493 	char b[BDEVNAME_SIZE];
1494 	printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
1495 		bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
1496 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1497 	        rdev->desc_nr);
1498 	if (rdev->sb_loaded) {
1499 		printk(KERN_INFO "md: rdev superblock:\n");
1500 		print_sb((mdp_super_t*)page_address(rdev->sb_page));
1501 	} else
1502 		printk(KERN_INFO "md: no rdev superblock!\n");
1503 }
1504 
1505 void md_print_devices(void)
1506 {
1507 	struct list_head *tmp, *tmp2;
1508 	mdk_rdev_t *rdev;
1509 	mddev_t *mddev;
1510 	char b[BDEVNAME_SIZE];
1511 
1512 	printk("\n");
1513 	printk("md:	**********************************\n");
1514 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1515 	printk("md:	**********************************\n");
1516 	ITERATE_MDDEV(mddev,tmp) {
1517 
1518 		if (mddev->bitmap)
1519 			bitmap_print_sb(mddev->bitmap);
1520 		else
1521 			printk("%s: ", mdname(mddev));
1522 		ITERATE_RDEV(mddev,rdev,tmp2)
1523 			printk("<%s>", bdevname(rdev->bdev,b));
1524 		printk("\n");
1525 
1526 		ITERATE_RDEV(mddev,rdev,tmp2)
1527 			print_rdev(rdev);
1528 	}
1529 	printk("md:	**********************************\n");
1530 	printk("\n");
1531 }
1532 
1533 
1534 static void sync_sbs(mddev_t * mddev)
1535 {
1536 	mdk_rdev_t *rdev;
1537 	struct list_head *tmp;
1538 
1539 	ITERATE_RDEV(mddev,rdev,tmp) {
1540 		super_types[mddev->major_version].
1541 			sync_super(mddev, rdev);
1542 		rdev->sb_loaded = 1;
1543 	}
1544 }
1545 
1546 void md_update_sb(mddev_t * mddev)
1547 {
1548 	int err;
1549 	struct list_head *tmp;
1550 	mdk_rdev_t *rdev;
1551 	int sync_req;
1552 
1553 repeat:
1554 	spin_lock_irq(&mddev->write_lock);
1555 	sync_req = mddev->in_sync;
1556 	mddev->utime = get_seconds();
1557 	mddev->events ++;
1558 
1559 	if (!mddev->events) {
1560 		/*
1561 		 * oops, this 64-bit counter should never wrap.
1562 		 * Either we are in around ~1 trillion A.C., assuming
1563 		 * 1 reboot per second, or we have a bug:
1564 		 */
1565 		MD_BUG();
1566 		mddev->events --;
1567 	}
1568 	mddev->sb_dirty = 2;
1569 	sync_sbs(mddev);
1570 
1571 	/*
1572 	 * do not write anything to disk if using
1573 	 * nonpersistent superblocks
1574 	 */
1575 	if (!mddev->persistent) {
1576 		mddev->sb_dirty = 0;
1577 		spin_unlock_irq(&mddev->write_lock);
1578 		wake_up(&mddev->sb_wait);
1579 		return;
1580 	}
1581 	spin_unlock_irq(&mddev->write_lock);
1582 
1583 	dprintk(KERN_INFO
1584 		"md: updating %s RAID superblock on device (in sync %d)\n",
1585 		mdname(mddev),mddev->in_sync);
1586 
1587 	err = bitmap_update_sb(mddev->bitmap);
1588 	ITERATE_RDEV(mddev,rdev,tmp) {
1589 		char b[BDEVNAME_SIZE];
1590 		dprintk(KERN_INFO "md: ");
1591 		if (test_bit(Faulty, &rdev->flags))
1592 			dprintk("(skipping faulty ");
1593 
1594 		dprintk("%s ", bdevname(rdev->bdev,b));
1595 		if (!test_bit(Faulty, &rdev->flags)) {
1596 			md_super_write(mddev,rdev,
1597 				       rdev->sb_offset<<1, rdev->sb_size,
1598 				       rdev->sb_page);
1599 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1600 				bdevname(rdev->bdev,b),
1601 				(unsigned long long)rdev->sb_offset);
1602 
1603 		} else
1604 			dprintk(")\n");
1605 		if (mddev->level == LEVEL_MULTIPATH)
1606 			/* only need to write one superblock... */
1607 			break;
1608 	}
1609 	md_super_wait(mddev);
1610 	/* if there was a failure, sb_dirty was set to 1, and we re-write super */
1611 
1612 	spin_lock_irq(&mddev->write_lock);
1613 	if (mddev->in_sync != sync_req|| mddev->sb_dirty == 1) {
1614 		/* have to write it out again */
1615 		spin_unlock_irq(&mddev->write_lock);
1616 		goto repeat;
1617 	}
1618 	mddev->sb_dirty = 0;
1619 	spin_unlock_irq(&mddev->write_lock);
1620 	wake_up(&mddev->sb_wait);
1621 
1622 }
1623 EXPORT_SYMBOL_GPL(md_update_sb);
1624 
1625 /* words written to sysfs files may, or my not, be \n terminated.
1626  * We want to accept with case. For this we use cmd_match.
1627  */
1628 static int cmd_match(const char *cmd, const char *str)
1629 {
1630 	/* See if cmd, written into a sysfs file, matches
1631 	 * str.  They must either be the same, or cmd can
1632 	 * have a trailing newline
1633 	 */
1634 	while (*cmd && *str && *cmd == *str) {
1635 		cmd++;
1636 		str++;
1637 	}
1638 	if (*cmd == '\n')
1639 		cmd++;
1640 	if (*str || *cmd)
1641 		return 0;
1642 	return 1;
1643 }
1644 
1645 struct rdev_sysfs_entry {
1646 	struct attribute attr;
1647 	ssize_t (*show)(mdk_rdev_t *, char *);
1648 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
1649 };
1650 
1651 static ssize_t
1652 state_show(mdk_rdev_t *rdev, char *page)
1653 {
1654 	char *sep = "";
1655 	int len=0;
1656 
1657 	if (test_bit(Faulty, &rdev->flags)) {
1658 		len+= sprintf(page+len, "%sfaulty",sep);
1659 		sep = ",";
1660 	}
1661 	if (test_bit(In_sync, &rdev->flags)) {
1662 		len += sprintf(page+len, "%sin_sync",sep);
1663 		sep = ",";
1664 	}
1665 	if (!test_bit(Faulty, &rdev->flags) &&
1666 	    !test_bit(In_sync, &rdev->flags)) {
1667 		len += sprintf(page+len, "%sspare", sep);
1668 		sep = ",";
1669 	}
1670 	return len+sprintf(page+len, "\n");
1671 }
1672 
1673 static struct rdev_sysfs_entry
1674 rdev_state = __ATTR_RO(state);
1675 
1676 static ssize_t
1677 super_show(mdk_rdev_t *rdev, char *page)
1678 {
1679 	if (rdev->sb_loaded && rdev->sb_size) {
1680 		memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
1681 		return rdev->sb_size;
1682 	} else
1683 		return 0;
1684 }
1685 static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
1686 
1687 static ssize_t
1688 errors_show(mdk_rdev_t *rdev, char *page)
1689 {
1690 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
1691 }
1692 
1693 static ssize_t
1694 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1695 {
1696 	char *e;
1697 	unsigned long n = simple_strtoul(buf, &e, 10);
1698 	if (*buf && (*e == 0 || *e == '\n')) {
1699 		atomic_set(&rdev->corrected_errors, n);
1700 		return len;
1701 	}
1702 	return -EINVAL;
1703 }
1704 static struct rdev_sysfs_entry rdev_errors =
1705 __ATTR(errors, 0644, errors_show, errors_store);
1706 
1707 static ssize_t
1708 slot_show(mdk_rdev_t *rdev, char *page)
1709 {
1710 	if (rdev->raid_disk < 0)
1711 		return sprintf(page, "none\n");
1712 	else
1713 		return sprintf(page, "%d\n", rdev->raid_disk);
1714 }
1715 
1716 static ssize_t
1717 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1718 {
1719 	char *e;
1720 	int slot = simple_strtoul(buf, &e, 10);
1721 	if (strncmp(buf, "none", 4)==0)
1722 		slot = -1;
1723 	else if (e==buf || (*e && *e!= '\n'))
1724 		return -EINVAL;
1725 	if (rdev->mddev->pers)
1726 		/* Cannot set slot in active array (yet) */
1727 		return -EBUSY;
1728 	if (slot >= rdev->mddev->raid_disks)
1729 		return -ENOSPC;
1730 	rdev->raid_disk = slot;
1731 	/* assume it is working */
1732 	rdev->flags = 0;
1733 	set_bit(In_sync, &rdev->flags);
1734 	return len;
1735 }
1736 
1737 
1738 static struct rdev_sysfs_entry rdev_slot =
1739 __ATTR(slot, 0644, slot_show, slot_store);
1740 
1741 static ssize_t
1742 offset_show(mdk_rdev_t *rdev, char *page)
1743 {
1744 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
1745 }
1746 
1747 static ssize_t
1748 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1749 {
1750 	char *e;
1751 	unsigned long long offset = simple_strtoull(buf, &e, 10);
1752 	if (e==buf || (*e && *e != '\n'))
1753 		return -EINVAL;
1754 	if (rdev->mddev->pers)
1755 		return -EBUSY;
1756 	rdev->data_offset = offset;
1757 	return len;
1758 }
1759 
1760 static struct rdev_sysfs_entry rdev_offset =
1761 __ATTR(offset, 0644, offset_show, offset_store);
1762 
1763 static ssize_t
1764 rdev_size_show(mdk_rdev_t *rdev, char *page)
1765 {
1766 	return sprintf(page, "%llu\n", (unsigned long long)rdev->size);
1767 }
1768 
1769 static ssize_t
1770 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1771 {
1772 	char *e;
1773 	unsigned long long size = simple_strtoull(buf, &e, 10);
1774 	if (e==buf || (*e && *e != '\n'))
1775 		return -EINVAL;
1776 	if (rdev->mddev->pers)
1777 		return -EBUSY;
1778 	rdev->size = size;
1779 	if (size < rdev->mddev->size || rdev->mddev->size == 0)
1780 		rdev->mddev->size = size;
1781 	return len;
1782 }
1783 
1784 static struct rdev_sysfs_entry rdev_size =
1785 __ATTR(size, 0644, rdev_size_show, rdev_size_store);
1786 
1787 static struct attribute *rdev_default_attrs[] = {
1788 	&rdev_state.attr,
1789 	&rdev_super.attr,
1790 	&rdev_errors.attr,
1791 	&rdev_slot.attr,
1792 	&rdev_offset.attr,
1793 	&rdev_size.attr,
1794 	NULL,
1795 };
1796 static ssize_t
1797 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
1798 {
1799 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1800 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1801 
1802 	if (!entry->show)
1803 		return -EIO;
1804 	return entry->show(rdev, page);
1805 }
1806 
1807 static ssize_t
1808 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
1809 	      const char *page, size_t length)
1810 {
1811 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1812 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1813 
1814 	if (!entry->store)
1815 		return -EIO;
1816 	return entry->store(rdev, page, length);
1817 }
1818 
1819 static void rdev_free(struct kobject *ko)
1820 {
1821 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
1822 	kfree(rdev);
1823 }
1824 static struct sysfs_ops rdev_sysfs_ops = {
1825 	.show		= rdev_attr_show,
1826 	.store		= rdev_attr_store,
1827 };
1828 static struct kobj_type rdev_ktype = {
1829 	.release	= rdev_free,
1830 	.sysfs_ops	= &rdev_sysfs_ops,
1831 	.default_attrs	= rdev_default_attrs,
1832 };
1833 
1834 /*
1835  * Import a device. If 'super_format' >= 0, then sanity check the superblock
1836  *
1837  * mark the device faulty if:
1838  *
1839  *   - the device is nonexistent (zero size)
1840  *   - the device has no valid superblock
1841  *
1842  * a faulty rdev _never_ has rdev->sb set.
1843  */
1844 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
1845 {
1846 	char b[BDEVNAME_SIZE];
1847 	int err;
1848 	mdk_rdev_t *rdev;
1849 	sector_t size;
1850 
1851 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
1852 	if (!rdev) {
1853 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
1854 		return ERR_PTR(-ENOMEM);
1855 	}
1856 
1857 	if ((err = alloc_disk_sb(rdev)))
1858 		goto abort_free;
1859 
1860 	err = lock_rdev(rdev, newdev);
1861 	if (err)
1862 		goto abort_free;
1863 
1864 	rdev->kobj.parent = NULL;
1865 	rdev->kobj.ktype = &rdev_ktype;
1866 	kobject_init(&rdev->kobj);
1867 
1868 	rdev->desc_nr = -1;
1869 	rdev->flags = 0;
1870 	rdev->data_offset = 0;
1871 	atomic_set(&rdev->nr_pending, 0);
1872 	atomic_set(&rdev->read_errors, 0);
1873 	atomic_set(&rdev->corrected_errors, 0);
1874 
1875 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
1876 	if (!size) {
1877 		printk(KERN_WARNING
1878 			"md: %s has zero or unknown size, marking faulty!\n",
1879 			bdevname(rdev->bdev,b));
1880 		err = -EINVAL;
1881 		goto abort_free;
1882 	}
1883 
1884 	if (super_format >= 0) {
1885 		err = super_types[super_format].
1886 			load_super(rdev, NULL, super_minor);
1887 		if (err == -EINVAL) {
1888 			printk(KERN_WARNING
1889 				"md: %s has invalid sb, not importing!\n",
1890 				bdevname(rdev->bdev,b));
1891 			goto abort_free;
1892 		}
1893 		if (err < 0) {
1894 			printk(KERN_WARNING
1895 				"md: could not read %s's sb, not importing!\n",
1896 				bdevname(rdev->bdev,b));
1897 			goto abort_free;
1898 		}
1899 	}
1900 	INIT_LIST_HEAD(&rdev->same_set);
1901 
1902 	return rdev;
1903 
1904 abort_free:
1905 	if (rdev->sb_page) {
1906 		if (rdev->bdev)
1907 			unlock_rdev(rdev);
1908 		free_disk_sb(rdev);
1909 	}
1910 	kfree(rdev);
1911 	return ERR_PTR(err);
1912 }
1913 
1914 /*
1915  * Check a full RAID array for plausibility
1916  */
1917 
1918 
1919 static void analyze_sbs(mddev_t * mddev)
1920 {
1921 	int i;
1922 	struct list_head *tmp;
1923 	mdk_rdev_t *rdev, *freshest;
1924 	char b[BDEVNAME_SIZE];
1925 
1926 	freshest = NULL;
1927 	ITERATE_RDEV(mddev,rdev,tmp)
1928 		switch (super_types[mddev->major_version].
1929 			load_super(rdev, freshest, mddev->minor_version)) {
1930 		case 1:
1931 			freshest = rdev;
1932 			break;
1933 		case 0:
1934 			break;
1935 		default:
1936 			printk( KERN_ERR \
1937 				"md: fatal superblock inconsistency in %s"
1938 				" -- removing from array\n",
1939 				bdevname(rdev->bdev,b));
1940 			kick_rdev_from_array(rdev);
1941 		}
1942 
1943 
1944 	super_types[mddev->major_version].
1945 		validate_super(mddev, freshest);
1946 
1947 	i = 0;
1948 	ITERATE_RDEV(mddev,rdev,tmp) {
1949 		if (rdev != freshest)
1950 			if (super_types[mddev->major_version].
1951 			    validate_super(mddev, rdev)) {
1952 				printk(KERN_WARNING "md: kicking non-fresh %s"
1953 					" from array!\n",
1954 					bdevname(rdev->bdev,b));
1955 				kick_rdev_from_array(rdev);
1956 				continue;
1957 			}
1958 		if (mddev->level == LEVEL_MULTIPATH) {
1959 			rdev->desc_nr = i++;
1960 			rdev->raid_disk = rdev->desc_nr;
1961 			set_bit(In_sync, &rdev->flags);
1962 		}
1963 	}
1964 
1965 
1966 
1967 	if (mddev->recovery_cp != MaxSector &&
1968 	    mddev->level >= 1)
1969 		printk(KERN_ERR "md: %s: raid array is not clean"
1970 		       " -- starting background reconstruction\n",
1971 		       mdname(mddev));
1972 
1973 }
1974 
1975 static ssize_t
1976 level_show(mddev_t *mddev, char *page)
1977 {
1978 	struct mdk_personality *p = mddev->pers;
1979 	if (p)
1980 		return sprintf(page, "%s\n", p->name);
1981 	else if (mddev->clevel[0])
1982 		return sprintf(page, "%s\n", mddev->clevel);
1983 	else if (mddev->level != LEVEL_NONE)
1984 		return sprintf(page, "%d\n", mddev->level);
1985 	else
1986 		return 0;
1987 }
1988 
1989 static ssize_t
1990 level_store(mddev_t *mddev, const char *buf, size_t len)
1991 {
1992 	int rv = len;
1993 	if (mddev->pers)
1994 		return -EBUSY;
1995 	if (len == 0)
1996 		return 0;
1997 	if (len >= sizeof(mddev->clevel))
1998 		return -ENOSPC;
1999 	strncpy(mddev->clevel, buf, len);
2000 	if (mddev->clevel[len-1] == '\n')
2001 		len--;
2002 	mddev->clevel[len] = 0;
2003 	mddev->level = LEVEL_NONE;
2004 	return rv;
2005 }
2006 
2007 static struct md_sysfs_entry md_level =
2008 __ATTR(level, 0644, level_show, level_store);
2009 
2010 static ssize_t
2011 raid_disks_show(mddev_t *mddev, char *page)
2012 {
2013 	if (mddev->raid_disks == 0)
2014 		return 0;
2015 	return sprintf(page, "%d\n", mddev->raid_disks);
2016 }
2017 
2018 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2019 
2020 static ssize_t
2021 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2022 {
2023 	/* can only set raid_disks if array is not yet active */
2024 	char *e;
2025 	int rv = 0;
2026 	unsigned long n = simple_strtoul(buf, &e, 10);
2027 
2028 	if (!*buf || (*e && *e != '\n'))
2029 		return -EINVAL;
2030 
2031 	if (mddev->pers)
2032 		rv = update_raid_disks(mddev, n);
2033 	else
2034 		mddev->raid_disks = n;
2035 	return rv ? rv : len;
2036 }
2037 static struct md_sysfs_entry md_raid_disks =
2038 __ATTR(raid_disks, 0644, raid_disks_show, raid_disks_store);
2039 
2040 static ssize_t
2041 chunk_size_show(mddev_t *mddev, char *page)
2042 {
2043 	return sprintf(page, "%d\n", mddev->chunk_size);
2044 }
2045 
2046 static ssize_t
2047 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2048 {
2049 	/* can only set chunk_size if array is not yet active */
2050 	char *e;
2051 	unsigned long n = simple_strtoul(buf, &e, 10);
2052 
2053 	if (mddev->pers)
2054 		return -EBUSY;
2055 	if (!*buf || (*e && *e != '\n'))
2056 		return -EINVAL;
2057 
2058 	mddev->chunk_size = n;
2059 	return len;
2060 }
2061 static struct md_sysfs_entry md_chunk_size =
2062 __ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store);
2063 
2064 static ssize_t
2065 null_show(mddev_t *mddev, char *page)
2066 {
2067 	return -EINVAL;
2068 }
2069 
2070 static ssize_t
2071 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
2072 {
2073 	/* buf must be %d:%d\n? giving major and minor numbers */
2074 	/* The new device is added to the array.
2075 	 * If the array has a persistent superblock, we read the
2076 	 * superblock to initialise info and check validity.
2077 	 * Otherwise, only checking done is that in bind_rdev_to_array,
2078 	 * which mainly checks size.
2079 	 */
2080 	char *e;
2081 	int major = simple_strtoul(buf, &e, 10);
2082 	int minor;
2083 	dev_t dev;
2084 	mdk_rdev_t *rdev;
2085 	int err;
2086 
2087 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
2088 		return -EINVAL;
2089 	minor = simple_strtoul(e+1, &e, 10);
2090 	if (*e && *e != '\n')
2091 		return -EINVAL;
2092 	dev = MKDEV(major, minor);
2093 	if (major != MAJOR(dev) ||
2094 	    minor != MINOR(dev))
2095 		return -EOVERFLOW;
2096 
2097 
2098 	if (mddev->persistent) {
2099 		rdev = md_import_device(dev, mddev->major_version,
2100 					mddev->minor_version);
2101 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
2102 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
2103 						       mdk_rdev_t, same_set);
2104 			err = super_types[mddev->major_version]
2105 				.load_super(rdev, rdev0, mddev->minor_version);
2106 			if (err < 0)
2107 				goto out;
2108 		}
2109 	} else
2110 		rdev = md_import_device(dev, -1, -1);
2111 
2112 	if (IS_ERR(rdev))
2113 		return PTR_ERR(rdev);
2114 	err = bind_rdev_to_array(rdev, mddev);
2115  out:
2116 	if (err)
2117 		export_rdev(rdev);
2118 	return err ? err : len;
2119 }
2120 
2121 static struct md_sysfs_entry md_new_device =
2122 __ATTR(new_dev, 0200, null_show, new_dev_store);
2123 
2124 static ssize_t
2125 size_show(mddev_t *mddev, char *page)
2126 {
2127 	return sprintf(page, "%llu\n", (unsigned long long)mddev->size);
2128 }
2129 
2130 static int update_size(mddev_t *mddev, unsigned long size);
2131 
2132 static ssize_t
2133 size_store(mddev_t *mddev, const char *buf, size_t len)
2134 {
2135 	/* If array is inactive, we can reduce the component size, but
2136 	 * not increase it (except from 0).
2137 	 * If array is active, we can try an on-line resize
2138 	 */
2139 	char *e;
2140 	int err = 0;
2141 	unsigned long long size = simple_strtoull(buf, &e, 10);
2142 	if (!*buf || *buf == '\n' ||
2143 	    (*e && *e != '\n'))
2144 		return -EINVAL;
2145 
2146 	if (mddev->pers) {
2147 		err = update_size(mddev, size);
2148 		md_update_sb(mddev);
2149 	} else {
2150 		if (mddev->size == 0 ||
2151 		    mddev->size > size)
2152 			mddev->size = size;
2153 		else
2154 			err = -ENOSPC;
2155 	}
2156 	return err ? err : len;
2157 }
2158 
2159 static struct md_sysfs_entry md_size =
2160 __ATTR(component_size, 0644, size_show, size_store);
2161 
2162 
2163 /* Metdata version.
2164  * This is either 'none' for arrays with externally managed metadata,
2165  * or N.M for internally known formats
2166  */
2167 static ssize_t
2168 metadata_show(mddev_t *mddev, char *page)
2169 {
2170 	if (mddev->persistent)
2171 		return sprintf(page, "%d.%d\n",
2172 			       mddev->major_version, mddev->minor_version);
2173 	else
2174 		return sprintf(page, "none\n");
2175 }
2176 
2177 static ssize_t
2178 metadata_store(mddev_t *mddev, const char *buf, size_t len)
2179 {
2180 	int major, minor;
2181 	char *e;
2182 	if (!list_empty(&mddev->disks))
2183 		return -EBUSY;
2184 
2185 	if (cmd_match(buf, "none")) {
2186 		mddev->persistent = 0;
2187 		mddev->major_version = 0;
2188 		mddev->minor_version = 90;
2189 		return len;
2190 	}
2191 	major = simple_strtoul(buf, &e, 10);
2192 	if (e==buf || *e != '.')
2193 		return -EINVAL;
2194 	buf = e+1;
2195 	minor = simple_strtoul(buf, &e, 10);
2196 	if (e==buf || *e != '\n')
2197 		return -EINVAL;
2198 	if (major >= sizeof(super_types)/sizeof(super_types[0]) ||
2199 	    super_types[major].name == NULL)
2200 		return -ENOENT;
2201 	mddev->major_version = major;
2202 	mddev->minor_version = minor;
2203 	mddev->persistent = 1;
2204 	return len;
2205 }
2206 
2207 static struct md_sysfs_entry md_metadata =
2208 __ATTR(metadata_version, 0644, metadata_show, metadata_store);
2209 
2210 static ssize_t
2211 action_show(mddev_t *mddev, char *page)
2212 {
2213 	char *type = "idle";
2214 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2215 	    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) {
2216 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
2217 			type = "reshape";
2218 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2219 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2220 				type = "resync";
2221 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
2222 				type = "check";
2223 			else
2224 				type = "repair";
2225 		} else
2226 			type = "recover";
2227 	}
2228 	return sprintf(page, "%s\n", type);
2229 }
2230 
2231 static ssize_t
2232 action_store(mddev_t *mddev, const char *page, size_t len)
2233 {
2234 	if (!mddev->pers || !mddev->pers->sync_request)
2235 		return -EINVAL;
2236 
2237 	if (cmd_match(page, "idle")) {
2238 		if (mddev->sync_thread) {
2239 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2240 			md_unregister_thread(mddev->sync_thread);
2241 			mddev->sync_thread = NULL;
2242 			mddev->recovery = 0;
2243 		}
2244 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2245 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
2246 		return -EBUSY;
2247 	else if (cmd_match(page, "resync") || cmd_match(page, "recover"))
2248 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2249 	else if (cmd_match(page, "reshape")) {
2250 		int err;
2251 		if (mddev->pers->start_reshape == NULL)
2252 			return -EINVAL;
2253 		err = mddev->pers->start_reshape(mddev);
2254 		if (err)
2255 			return err;
2256 	} else {
2257 		if (cmd_match(page, "check"))
2258 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
2259 		else if (cmd_match(page, "repair"))
2260 			return -EINVAL;
2261 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
2262 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
2263 	}
2264 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2265 	md_wakeup_thread(mddev->thread);
2266 	return len;
2267 }
2268 
2269 static ssize_t
2270 mismatch_cnt_show(mddev_t *mddev, char *page)
2271 {
2272 	return sprintf(page, "%llu\n",
2273 		       (unsigned long long) mddev->resync_mismatches);
2274 }
2275 
2276 static struct md_sysfs_entry
2277 md_scan_mode = __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
2278 
2279 
2280 static struct md_sysfs_entry
2281 md_mismatches = __ATTR_RO(mismatch_cnt);
2282 
2283 static ssize_t
2284 sync_min_show(mddev_t *mddev, char *page)
2285 {
2286 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
2287 		       mddev->sync_speed_min ? "local": "system");
2288 }
2289 
2290 static ssize_t
2291 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
2292 {
2293 	int min;
2294 	char *e;
2295 	if (strncmp(buf, "system", 6)==0) {
2296 		mddev->sync_speed_min = 0;
2297 		return len;
2298 	}
2299 	min = simple_strtoul(buf, &e, 10);
2300 	if (buf == e || (*e && *e != '\n') || min <= 0)
2301 		return -EINVAL;
2302 	mddev->sync_speed_min = min;
2303 	return len;
2304 }
2305 
2306 static struct md_sysfs_entry md_sync_min =
2307 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
2308 
2309 static ssize_t
2310 sync_max_show(mddev_t *mddev, char *page)
2311 {
2312 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
2313 		       mddev->sync_speed_max ? "local": "system");
2314 }
2315 
2316 static ssize_t
2317 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
2318 {
2319 	int max;
2320 	char *e;
2321 	if (strncmp(buf, "system", 6)==0) {
2322 		mddev->sync_speed_max = 0;
2323 		return len;
2324 	}
2325 	max = simple_strtoul(buf, &e, 10);
2326 	if (buf == e || (*e && *e != '\n') || max <= 0)
2327 		return -EINVAL;
2328 	mddev->sync_speed_max = max;
2329 	return len;
2330 }
2331 
2332 static struct md_sysfs_entry md_sync_max =
2333 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
2334 
2335 
2336 static ssize_t
2337 sync_speed_show(mddev_t *mddev, char *page)
2338 {
2339 	unsigned long resync, dt, db;
2340 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
2341 	dt = ((jiffies - mddev->resync_mark) / HZ);
2342 	if (!dt) dt++;
2343 	db = resync - (mddev->resync_mark_cnt);
2344 	return sprintf(page, "%ld\n", db/dt/2); /* K/sec */
2345 }
2346 
2347 static struct md_sysfs_entry
2348 md_sync_speed = __ATTR_RO(sync_speed);
2349 
2350 static ssize_t
2351 sync_completed_show(mddev_t *mddev, char *page)
2352 {
2353 	unsigned long max_blocks, resync;
2354 
2355 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2356 		max_blocks = mddev->resync_max_sectors;
2357 	else
2358 		max_blocks = mddev->size << 1;
2359 
2360 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
2361 	return sprintf(page, "%lu / %lu\n", resync, max_blocks);
2362 }
2363 
2364 static struct md_sysfs_entry
2365 md_sync_completed = __ATTR_RO(sync_completed);
2366 
2367 static ssize_t
2368 suspend_lo_show(mddev_t *mddev, char *page)
2369 {
2370 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
2371 }
2372 
2373 static ssize_t
2374 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
2375 {
2376 	char *e;
2377 	unsigned long long new = simple_strtoull(buf, &e, 10);
2378 
2379 	if (mddev->pers->quiesce == NULL)
2380 		return -EINVAL;
2381 	if (buf == e || (*e && *e != '\n'))
2382 		return -EINVAL;
2383 	if (new >= mddev->suspend_hi ||
2384 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
2385 		mddev->suspend_lo = new;
2386 		mddev->pers->quiesce(mddev, 2);
2387 		return len;
2388 	} else
2389 		return -EINVAL;
2390 }
2391 static struct md_sysfs_entry md_suspend_lo =
2392 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
2393 
2394 
2395 static ssize_t
2396 suspend_hi_show(mddev_t *mddev, char *page)
2397 {
2398 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
2399 }
2400 
2401 static ssize_t
2402 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
2403 {
2404 	char *e;
2405 	unsigned long long new = simple_strtoull(buf, &e, 10);
2406 
2407 	if (mddev->pers->quiesce == NULL)
2408 		return -EINVAL;
2409 	if (buf == e || (*e && *e != '\n'))
2410 		return -EINVAL;
2411 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
2412 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
2413 		mddev->suspend_hi = new;
2414 		mddev->pers->quiesce(mddev, 1);
2415 		mddev->pers->quiesce(mddev, 0);
2416 		return len;
2417 	} else
2418 		return -EINVAL;
2419 }
2420 static struct md_sysfs_entry md_suspend_hi =
2421 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
2422 
2423 
2424 static struct attribute *md_default_attrs[] = {
2425 	&md_level.attr,
2426 	&md_raid_disks.attr,
2427 	&md_chunk_size.attr,
2428 	&md_size.attr,
2429 	&md_metadata.attr,
2430 	&md_new_device.attr,
2431 	NULL,
2432 };
2433 
2434 static struct attribute *md_redundancy_attrs[] = {
2435 	&md_scan_mode.attr,
2436 	&md_mismatches.attr,
2437 	&md_sync_min.attr,
2438 	&md_sync_max.attr,
2439 	&md_sync_speed.attr,
2440 	&md_sync_completed.attr,
2441 	&md_suspend_lo.attr,
2442 	&md_suspend_hi.attr,
2443 	NULL,
2444 };
2445 static struct attribute_group md_redundancy_group = {
2446 	.name = NULL,
2447 	.attrs = md_redundancy_attrs,
2448 };
2449 
2450 
2451 static ssize_t
2452 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2453 {
2454 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
2455 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
2456 	ssize_t rv;
2457 
2458 	if (!entry->show)
2459 		return -EIO;
2460 	mddev_lock(mddev);
2461 	rv = entry->show(mddev, page);
2462 	mddev_unlock(mddev);
2463 	return rv;
2464 }
2465 
2466 static ssize_t
2467 md_attr_store(struct kobject *kobj, struct attribute *attr,
2468 	      const char *page, size_t length)
2469 {
2470 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
2471 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
2472 	ssize_t rv;
2473 
2474 	if (!entry->store)
2475 		return -EIO;
2476 	mddev_lock(mddev);
2477 	rv = entry->store(mddev, page, length);
2478 	mddev_unlock(mddev);
2479 	return rv;
2480 }
2481 
2482 static void md_free(struct kobject *ko)
2483 {
2484 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
2485 	kfree(mddev);
2486 }
2487 
2488 static struct sysfs_ops md_sysfs_ops = {
2489 	.show	= md_attr_show,
2490 	.store	= md_attr_store,
2491 };
2492 static struct kobj_type md_ktype = {
2493 	.release	= md_free,
2494 	.sysfs_ops	= &md_sysfs_ops,
2495 	.default_attrs	= md_default_attrs,
2496 };
2497 
2498 int mdp_major = 0;
2499 
2500 static struct kobject *md_probe(dev_t dev, int *part, void *data)
2501 {
2502 	static DEFINE_MUTEX(disks_mutex);
2503 	mddev_t *mddev = mddev_find(dev);
2504 	struct gendisk *disk;
2505 	int partitioned = (MAJOR(dev) != MD_MAJOR);
2506 	int shift = partitioned ? MdpMinorShift : 0;
2507 	int unit = MINOR(dev) >> shift;
2508 
2509 	if (!mddev)
2510 		return NULL;
2511 
2512 	mutex_lock(&disks_mutex);
2513 	if (mddev->gendisk) {
2514 		mutex_unlock(&disks_mutex);
2515 		mddev_put(mddev);
2516 		return NULL;
2517 	}
2518 	disk = alloc_disk(1 << shift);
2519 	if (!disk) {
2520 		mutex_unlock(&disks_mutex);
2521 		mddev_put(mddev);
2522 		return NULL;
2523 	}
2524 	disk->major = MAJOR(dev);
2525 	disk->first_minor = unit << shift;
2526 	if (partitioned) {
2527 		sprintf(disk->disk_name, "md_d%d", unit);
2528 		sprintf(disk->devfs_name, "md/d%d", unit);
2529 	} else {
2530 		sprintf(disk->disk_name, "md%d", unit);
2531 		sprintf(disk->devfs_name, "md/%d", unit);
2532 	}
2533 	disk->fops = &md_fops;
2534 	disk->private_data = mddev;
2535 	disk->queue = mddev->queue;
2536 	add_disk(disk);
2537 	mddev->gendisk = disk;
2538 	mutex_unlock(&disks_mutex);
2539 	mddev->kobj.parent = &disk->kobj;
2540 	mddev->kobj.k_name = NULL;
2541 	snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
2542 	mddev->kobj.ktype = &md_ktype;
2543 	kobject_register(&mddev->kobj);
2544 	return NULL;
2545 }
2546 
2547 void md_wakeup_thread(mdk_thread_t *thread);
2548 
2549 static void md_safemode_timeout(unsigned long data)
2550 {
2551 	mddev_t *mddev = (mddev_t *) data;
2552 
2553 	mddev->safemode = 1;
2554 	md_wakeup_thread(mddev->thread);
2555 }
2556 
2557 static int start_dirty_degraded;
2558 
2559 static int do_md_run(mddev_t * mddev)
2560 {
2561 	int err;
2562 	int chunk_size;
2563 	struct list_head *tmp;
2564 	mdk_rdev_t *rdev;
2565 	struct gendisk *disk;
2566 	struct mdk_personality *pers;
2567 	char b[BDEVNAME_SIZE];
2568 
2569 	if (list_empty(&mddev->disks))
2570 		/* cannot run an array with no devices.. */
2571 		return -EINVAL;
2572 
2573 	if (mddev->pers)
2574 		return -EBUSY;
2575 
2576 	/*
2577 	 * Analyze all RAID superblock(s)
2578 	 */
2579 	if (!mddev->raid_disks)
2580 		analyze_sbs(mddev);
2581 
2582 	chunk_size = mddev->chunk_size;
2583 
2584 	if (chunk_size) {
2585 		if (chunk_size > MAX_CHUNK_SIZE) {
2586 			printk(KERN_ERR "too big chunk_size: %d > %d\n",
2587 				chunk_size, MAX_CHUNK_SIZE);
2588 			return -EINVAL;
2589 		}
2590 		/*
2591 		 * chunk-size has to be a power of 2 and multiples of PAGE_SIZE
2592 		 */
2593 		if ( (1 << ffz(~chunk_size)) != chunk_size) {
2594 			printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
2595 			return -EINVAL;
2596 		}
2597 		if (chunk_size < PAGE_SIZE) {
2598 			printk(KERN_ERR "too small chunk_size: %d < %ld\n",
2599 				chunk_size, PAGE_SIZE);
2600 			return -EINVAL;
2601 		}
2602 
2603 		/* devices must have minimum size of one chunk */
2604 		ITERATE_RDEV(mddev,rdev,tmp) {
2605 			if (test_bit(Faulty, &rdev->flags))
2606 				continue;
2607 			if (rdev->size < chunk_size / 1024) {
2608 				printk(KERN_WARNING
2609 					"md: Dev %s smaller than chunk_size:"
2610 					" %lluk < %dk\n",
2611 					bdevname(rdev->bdev,b),
2612 					(unsigned long long)rdev->size,
2613 					chunk_size / 1024);
2614 				return -EINVAL;
2615 			}
2616 		}
2617 	}
2618 
2619 #ifdef CONFIG_KMOD
2620 	if (mddev->level != LEVEL_NONE)
2621 		request_module("md-level-%d", mddev->level);
2622 	else if (mddev->clevel[0])
2623 		request_module("md-%s", mddev->clevel);
2624 #endif
2625 
2626 	/*
2627 	 * Drop all container device buffers, from now on
2628 	 * the only valid external interface is through the md
2629 	 * device.
2630 	 * Also find largest hardsector size
2631 	 */
2632 	ITERATE_RDEV(mddev,rdev,tmp) {
2633 		if (test_bit(Faulty, &rdev->flags))
2634 			continue;
2635 		sync_blockdev(rdev->bdev);
2636 		invalidate_bdev(rdev->bdev, 0);
2637 	}
2638 
2639 	md_probe(mddev->unit, NULL, NULL);
2640 	disk = mddev->gendisk;
2641 	if (!disk)
2642 		return -ENOMEM;
2643 
2644 	spin_lock(&pers_lock);
2645 	pers = find_pers(mddev->level, mddev->clevel);
2646 	if (!pers || !try_module_get(pers->owner)) {
2647 		spin_unlock(&pers_lock);
2648 		if (mddev->level != LEVEL_NONE)
2649 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
2650 			       mddev->level);
2651 		else
2652 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
2653 			       mddev->clevel);
2654 		return -EINVAL;
2655 	}
2656 	mddev->pers = pers;
2657 	spin_unlock(&pers_lock);
2658 	mddev->level = pers->level;
2659 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
2660 
2661 	if (mddev->reshape_position != MaxSector &&
2662 	    pers->start_reshape == NULL) {
2663 		/* This personality cannot handle reshaping... */
2664 		mddev->pers = NULL;
2665 		module_put(pers->owner);
2666 		return -EINVAL;
2667 	}
2668 
2669 	mddev->recovery = 0;
2670 	mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
2671 	mddev->barriers_work = 1;
2672 	mddev->ok_start_degraded = start_dirty_degraded;
2673 
2674 	if (start_readonly)
2675 		mddev->ro = 2; /* read-only, but switch on first write */
2676 
2677 	err = mddev->pers->run(mddev);
2678 	if (!err && mddev->pers->sync_request) {
2679 		err = bitmap_create(mddev);
2680 		if (err) {
2681 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
2682 			       mdname(mddev), err);
2683 			mddev->pers->stop(mddev);
2684 		}
2685 	}
2686 	if (err) {
2687 		printk(KERN_ERR "md: pers->run() failed ...\n");
2688 		module_put(mddev->pers->owner);
2689 		mddev->pers = NULL;
2690 		bitmap_destroy(mddev);
2691 		return err;
2692 	}
2693 	if (mddev->pers->sync_request)
2694 		sysfs_create_group(&mddev->kobj, &md_redundancy_group);
2695 	else if (mddev->ro == 2) /* auto-readonly not meaningful */
2696 		mddev->ro = 0;
2697 
2698  	atomic_set(&mddev->writes_pending,0);
2699 	mddev->safemode = 0;
2700 	mddev->safemode_timer.function = md_safemode_timeout;
2701 	mddev->safemode_timer.data = (unsigned long) mddev;
2702 	mddev->safemode_delay = (20 * HZ)/1000 +1; /* 20 msec delay */
2703 	mddev->in_sync = 1;
2704 
2705 	ITERATE_RDEV(mddev,rdev,tmp)
2706 		if (rdev->raid_disk >= 0) {
2707 			char nm[20];
2708 			sprintf(nm, "rd%d", rdev->raid_disk);
2709 			sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
2710 		}
2711 
2712 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2713 	md_wakeup_thread(mddev->thread);
2714 
2715 	if (mddev->sb_dirty)
2716 		md_update_sb(mddev);
2717 
2718 	set_capacity(disk, mddev->array_size<<1);
2719 
2720 	/* If we call blk_queue_make_request here, it will
2721 	 * re-initialise max_sectors etc which may have been
2722 	 * refined inside -> run.  So just set the bits we need to set.
2723 	 * Most initialisation happended when we called
2724 	 * blk_queue_make_request(..., md_fail_request)
2725 	 * earlier.
2726 	 */
2727 	mddev->queue->queuedata = mddev;
2728 	mddev->queue->make_request_fn = mddev->pers->make_request;
2729 
2730 	mddev->changed = 1;
2731 	md_new_event(mddev);
2732 	return 0;
2733 }
2734 
2735 static int restart_array(mddev_t *mddev)
2736 {
2737 	struct gendisk *disk = mddev->gendisk;
2738 	int err;
2739 
2740 	/*
2741 	 * Complain if it has no devices
2742 	 */
2743 	err = -ENXIO;
2744 	if (list_empty(&mddev->disks))
2745 		goto out;
2746 
2747 	if (mddev->pers) {
2748 		err = -EBUSY;
2749 		if (!mddev->ro)
2750 			goto out;
2751 
2752 		mddev->safemode = 0;
2753 		mddev->ro = 0;
2754 		set_disk_ro(disk, 0);
2755 
2756 		printk(KERN_INFO "md: %s switched to read-write mode.\n",
2757 			mdname(mddev));
2758 		/*
2759 		 * Kick recovery or resync if necessary
2760 		 */
2761 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2762 		md_wakeup_thread(mddev->thread);
2763 		err = 0;
2764 	} else {
2765 		printk(KERN_ERR "md: %s has no personality assigned.\n",
2766 			mdname(mddev));
2767 		err = -EINVAL;
2768 	}
2769 
2770 out:
2771 	return err;
2772 }
2773 
2774 static int do_md_stop(mddev_t * mddev, int ro)
2775 {
2776 	int err = 0;
2777 	struct gendisk *disk = mddev->gendisk;
2778 
2779 	if (mddev->pers) {
2780 		if (atomic_read(&mddev->active)>2) {
2781 			printk("md: %s still in use.\n",mdname(mddev));
2782 			return -EBUSY;
2783 		}
2784 
2785 		if (mddev->sync_thread) {
2786 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2787 			md_unregister_thread(mddev->sync_thread);
2788 			mddev->sync_thread = NULL;
2789 		}
2790 
2791 		del_timer_sync(&mddev->safemode_timer);
2792 
2793 		invalidate_partition(disk, 0);
2794 
2795 		if (ro) {
2796 			err  = -ENXIO;
2797 			if (mddev->ro==1)
2798 				goto out;
2799 			mddev->ro = 1;
2800 		} else {
2801 			bitmap_flush(mddev);
2802 			md_super_wait(mddev);
2803 			if (mddev->ro)
2804 				set_disk_ro(disk, 0);
2805 			blk_queue_make_request(mddev->queue, md_fail_request);
2806 			mddev->pers->stop(mddev);
2807 			if (mddev->pers->sync_request)
2808 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
2809 
2810 			module_put(mddev->pers->owner);
2811 			mddev->pers = NULL;
2812 			if (mddev->ro)
2813 				mddev->ro = 0;
2814 		}
2815 		if (!mddev->in_sync) {
2816 			/* mark array as shutdown cleanly */
2817 			mddev->in_sync = 1;
2818 			md_update_sb(mddev);
2819 		}
2820 		if (ro)
2821 			set_disk_ro(disk, 1);
2822 	}
2823 
2824 	/*
2825 	 * Free resources if final stop
2826 	 */
2827 	if (!ro) {
2828 		mdk_rdev_t *rdev;
2829 		struct list_head *tmp;
2830 		struct gendisk *disk;
2831 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
2832 
2833 		bitmap_destroy(mddev);
2834 		if (mddev->bitmap_file) {
2835 			atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
2836 			fput(mddev->bitmap_file);
2837 			mddev->bitmap_file = NULL;
2838 		}
2839 		mddev->bitmap_offset = 0;
2840 
2841 		ITERATE_RDEV(mddev,rdev,tmp)
2842 			if (rdev->raid_disk >= 0) {
2843 				char nm[20];
2844 				sprintf(nm, "rd%d", rdev->raid_disk);
2845 				sysfs_remove_link(&mddev->kobj, nm);
2846 			}
2847 
2848 		export_array(mddev);
2849 
2850 		mddev->array_size = 0;
2851 		disk = mddev->gendisk;
2852 		if (disk)
2853 			set_capacity(disk, 0);
2854 		mddev->changed = 1;
2855 	} else
2856 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
2857 			mdname(mddev));
2858 	err = 0;
2859 	md_new_event(mddev);
2860 out:
2861 	return err;
2862 }
2863 
2864 static void autorun_array(mddev_t *mddev)
2865 {
2866 	mdk_rdev_t *rdev;
2867 	struct list_head *tmp;
2868 	int err;
2869 
2870 	if (list_empty(&mddev->disks))
2871 		return;
2872 
2873 	printk(KERN_INFO "md: running: ");
2874 
2875 	ITERATE_RDEV(mddev,rdev,tmp) {
2876 		char b[BDEVNAME_SIZE];
2877 		printk("<%s>", bdevname(rdev->bdev,b));
2878 	}
2879 	printk("\n");
2880 
2881 	err = do_md_run (mddev);
2882 	if (err) {
2883 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
2884 		do_md_stop (mddev, 0);
2885 	}
2886 }
2887 
2888 /*
2889  * lets try to run arrays based on all disks that have arrived
2890  * until now. (those are in pending_raid_disks)
2891  *
2892  * the method: pick the first pending disk, collect all disks with
2893  * the same UUID, remove all from the pending list and put them into
2894  * the 'same_array' list. Then order this list based on superblock
2895  * update time (freshest comes first), kick out 'old' disks and
2896  * compare superblocks. If everything's fine then run it.
2897  *
2898  * If "unit" is allocated, then bump its reference count
2899  */
2900 static void autorun_devices(int part)
2901 {
2902 	struct list_head *tmp;
2903 	mdk_rdev_t *rdev0, *rdev;
2904 	mddev_t *mddev;
2905 	char b[BDEVNAME_SIZE];
2906 
2907 	printk(KERN_INFO "md: autorun ...\n");
2908 	while (!list_empty(&pending_raid_disks)) {
2909 		dev_t dev;
2910 		LIST_HEAD(candidates);
2911 		rdev0 = list_entry(pending_raid_disks.next,
2912 					 mdk_rdev_t, same_set);
2913 
2914 		printk(KERN_INFO "md: considering %s ...\n",
2915 			bdevname(rdev0->bdev,b));
2916 		INIT_LIST_HEAD(&candidates);
2917 		ITERATE_RDEV_PENDING(rdev,tmp)
2918 			if (super_90_load(rdev, rdev0, 0) >= 0) {
2919 				printk(KERN_INFO "md:  adding %s ...\n",
2920 					bdevname(rdev->bdev,b));
2921 				list_move(&rdev->same_set, &candidates);
2922 			}
2923 		/*
2924 		 * now we have a set of devices, with all of them having
2925 		 * mostly sane superblocks. It's time to allocate the
2926 		 * mddev.
2927 		 */
2928 		if (rdev0->preferred_minor < 0 || rdev0->preferred_minor >= MAX_MD_DEVS) {
2929 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
2930 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
2931 			break;
2932 		}
2933 		if (part)
2934 			dev = MKDEV(mdp_major,
2935 				    rdev0->preferred_minor << MdpMinorShift);
2936 		else
2937 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
2938 
2939 		md_probe(dev, NULL, NULL);
2940 		mddev = mddev_find(dev);
2941 		if (!mddev) {
2942 			printk(KERN_ERR
2943 				"md: cannot allocate memory for md drive.\n");
2944 			break;
2945 		}
2946 		if (mddev_lock(mddev))
2947 			printk(KERN_WARNING "md: %s locked, cannot run\n",
2948 			       mdname(mddev));
2949 		else if (mddev->raid_disks || mddev->major_version
2950 			 || !list_empty(&mddev->disks)) {
2951 			printk(KERN_WARNING
2952 				"md: %s already running, cannot run %s\n",
2953 				mdname(mddev), bdevname(rdev0->bdev,b));
2954 			mddev_unlock(mddev);
2955 		} else {
2956 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
2957 			ITERATE_RDEV_GENERIC(candidates,rdev,tmp) {
2958 				list_del_init(&rdev->same_set);
2959 				if (bind_rdev_to_array(rdev, mddev))
2960 					export_rdev(rdev);
2961 			}
2962 			autorun_array(mddev);
2963 			mddev_unlock(mddev);
2964 		}
2965 		/* on success, candidates will be empty, on error
2966 		 * it won't...
2967 		 */
2968 		ITERATE_RDEV_GENERIC(candidates,rdev,tmp)
2969 			export_rdev(rdev);
2970 		mddev_put(mddev);
2971 	}
2972 	printk(KERN_INFO "md: ... autorun DONE.\n");
2973 }
2974 
2975 /*
2976  * import RAID devices based on one partition
2977  * if possible, the array gets run as well.
2978  */
2979 
2980 static int autostart_array(dev_t startdev)
2981 {
2982 	char b[BDEVNAME_SIZE];
2983 	int err = -EINVAL, i;
2984 	mdp_super_t *sb = NULL;
2985 	mdk_rdev_t *start_rdev = NULL, *rdev;
2986 
2987 	start_rdev = md_import_device(startdev, 0, 0);
2988 	if (IS_ERR(start_rdev))
2989 		return err;
2990 
2991 
2992 	/* NOTE: this can only work for 0.90.0 superblocks */
2993 	sb = (mdp_super_t*)page_address(start_rdev->sb_page);
2994 	if (sb->major_version != 0 ||
2995 	    sb->minor_version != 90 ) {
2996 		printk(KERN_WARNING "md: can only autostart 0.90.0 arrays\n");
2997 		export_rdev(start_rdev);
2998 		return err;
2999 	}
3000 
3001 	if (test_bit(Faulty, &start_rdev->flags)) {
3002 		printk(KERN_WARNING
3003 			"md: can not autostart based on faulty %s!\n",
3004 			bdevname(start_rdev->bdev,b));
3005 		export_rdev(start_rdev);
3006 		return err;
3007 	}
3008 	list_add(&start_rdev->same_set, &pending_raid_disks);
3009 
3010 	for (i = 0; i < MD_SB_DISKS; i++) {
3011 		mdp_disk_t *desc = sb->disks + i;
3012 		dev_t dev = MKDEV(desc->major, desc->minor);
3013 
3014 		if (!dev)
3015 			continue;
3016 		if (dev == startdev)
3017 			continue;
3018 		if (MAJOR(dev) != desc->major || MINOR(dev) != desc->minor)
3019 			continue;
3020 		rdev = md_import_device(dev, 0, 0);
3021 		if (IS_ERR(rdev))
3022 			continue;
3023 
3024 		list_add(&rdev->same_set, &pending_raid_disks);
3025 	}
3026 
3027 	/*
3028 	 * possibly return codes
3029 	 */
3030 	autorun_devices(0);
3031 	return 0;
3032 
3033 }
3034 
3035 
3036 static int get_version(void __user * arg)
3037 {
3038 	mdu_version_t ver;
3039 
3040 	ver.major = MD_MAJOR_VERSION;
3041 	ver.minor = MD_MINOR_VERSION;
3042 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
3043 
3044 	if (copy_to_user(arg, &ver, sizeof(ver)))
3045 		return -EFAULT;
3046 
3047 	return 0;
3048 }
3049 
3050 static int get_array_info(mddev_t * mddev, void __user * arg)
3051 {
3052 	mdu_array_info_t info;
3053 	int nr,working,active,failed,spare;
3054 	mdk_rdev_t *rdev;
3055 	struct list_head *tmp;
3056 
3057 	nr=working=active=failed=spare=0;
3058 	ITERATE_RDEV(mddev,rdev,tmp) {
3059 		nr++;
3060 		if (test_bit(Faulty, &rdev->flags))
3061 			failed++;
3062 		else {
3063 			working++;
3064 			if (test_bit(In_sync, &rdev->flags))
3065 				active++;
3066 			else
3067 				spare++;
3068 		}
3069 	}
3070 
3071 	info.major_version = mddev->major_version;
3072 	info.minor_version = mddev->minor_version;
3073 	info.patch_version = MD_PATCHLEVEL_VERSION;
3074 	info.ctime         = mddev->ctime;
3075 	info.level         = mddev->level;
3076 	info.size          = mddev->size;
3077 	if (info.size != mddev->size) /* overflow */
3078 		info.size = -1;
3079 	info.nr_disks      = nr;
3080 	info.raid_disks    = mddev->raid_disks;
3081 	info.md_minor      = mddev->md_minor;
3082 	info.not_persistent= !mddev->persistent;
3083 
3084 	info.utime         = mddev->utime;
3085 	info.state         = 0;
3086 	if (mddev->in_sync)
3087 		info.state = (1<<MD_SB_CLEAN);
3088 	if (mddev->bitmap && mddev->bitmap_offset)
3089 		info.state = (1<<MD_SB_BITMAP_PRESENT);
3090 	info.active_disks  = active;
3091 	info.working_disks = working;
3092 	info.failed_disks  = failed;
3093 	info.spare_disks   = spare;
3094 
3095 	info.layout        = mddev->layout;
3096 	info.chunk_size    = mddev->chunk_size;
3097 
3098 	if (copy_to_user(arg, &info, sizeof(info)))
3099 		return -EFAULT;
3100 
3101 	return 0;
3102 }
3103 
3104 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
3105 {
3106 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
3107 	char *ptr, *buf = NULL;
3108 	int err = -ENOMEM;
3109 
3110 	file = kmalloc(sizeof(*file), GFP_KERNEL);
3111 	if (!file)
3112 		goto out;
3113 
3114 	/* bitmap disabled, zero the first byte and copy out */
3115 	if (!mddev->bitmap || !mddev->bitmap->file) {
3116 		file->pathname[0] = '\0';
3117 		goto copy_out;
3118 	}
3119 
3120 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
3121 	if (!buf)
3122 		goto out;
3123 
3124 	ptr = file_path(mddev->bitmap->file, buf, sizeof(file->pathname));
3125 	if (!ptr)
3126 		goto out;
3127 
3128 	strcpy(file->pathname, ptr);
3129 
3130 copy_out:
3131 	err = 0;
3132 	if (copy_to_user(arg, file, sizeof(*file)))
3133 		err = -EFAULT;
3134 out:
3135 	kfree(buf);
3136 	kfree(file);
3137 	return err;
3138 }
3139 
3140 static int get_disk_info(mddev_t * mddev, void __user * arg)
3141 {
3142 	mdu_disk_info_t info;
3143 	unsigned int nr;
3144 	mdk_rdev_t *rdev;
3145 
3146 	if (copy_from_user(&info, arg, sizeof(info)))
3147 		return -EFAULT;
3148 
3149 	nr = info.number;
3150 
3151 	rdev = find_rdev_nr(mddev, nr);
3152 	if (rdev) {
3153 		info.major = MAJOR(rdev->bdev->bd_dev);
3154 		info.minor = MINOR(rdev->bdev->bd_dev);
3155 		info.raid_disk = rdev->raid_disk;
3156 		info.state = 0;
3157 		if (test_bit(Faulty, &rdev->flags))
3158 			info.state |= (1<<MD_DISK_FAULTY);
3159 		else if (test_bit(In_sync, &rdev->flags)) {
3160 			info.state |= (1<<MD_DISK_ACTIVE);
3161 			info.state |= (1<<MD_DISK_SYNC);
3162 		}
3163 		if (test_bit(WriteMostly, &rdev->flags))
3164 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
3165 	} else {
3166 		info.major = info.minor = 0;
3167 		info.raid_disk = -1;
3168 		info.state = (1<<MD_DISK_REMOVED);
3169 	}
3170 
3171 	if (copy_to_user(arg, &info, sizeof(info)))
3172 		return -EFAULT;
3173 
3174 	return 0;
3175 }
3176 
3177 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
3178 {
3179 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
3180 	mdk_rdev_t *rdev;
3181 	dev_t dev = MKDEV(info->major,info->minor);
3182 
3183 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
3184 		return -EOVERFLOW;
3185 
3186 	if (!mddev->raid_disks) {
3187 		int err;
3188 		/* expecting a device which has a superblock */
3189 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
3190 		if (IS_ERR(rdev)) {
3191 			printk(KERN_WARNING
3192 				"md: md_import_device returned %ld\n",
3193 				PTR_ERR(rdev));
3194 			return PTR_ERR(rdev);
3195 		}
3196 		if (!list_empty(&mddev->disks)) {
3197 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3198 							mdk_rdev_t, same_set);
3199 			int err = super_types[mddev->major_version]
3200 				.load_super(rdev, rdev0, mddev->minor_version);
3201 			if (err < 0) {
3202 				printk(KERN_WARNING
3203 					"md: %s has different UUID to %s\n",
3204 					bdevname(rdev->bdev,b),
3205 					bdevname(rdev0->bdev,b2));
3206 				export_rdev(rdev);
3207 				return -EINVAL;
3208 			}
3209 		}
3210 		err = bind_rdev_to_array(rdev, mddev);
3211 		if (err)
3212 			export_rdev(rdev);
3213 		return err;
3214 	}
3215 
3216 	/*
3217 	 * add_new_disk can be used once the array is assembled
3218 	 * to add "hot spares".  They must already have a superblock
3219 	 * written
3220 	 */
3221 	if (mddev->pers) {
3222 		int err;
3223 		if (!mddev->pers->hot_add_disk) {
3224 			printk(KERN_WARNING
3225 				"%s: personality does not support diskops!\n",
3226 			       mdname(mddev));
3227 			return -EINVAL;
3228 		}
3229 		if (mddev->persistent)
3230 			rdev = md_import_device(dev, mddev->major_version,
3231 						mddev->minor_version);
3232 		else
3233 			rdev = md_import_device(dev, -1, -1);
3234 		if (IS_ERR(rdev)) {
3235 			printk(KERN_WARNING
3236 				"md: md_import_device returned %ld\n",
3237 				PTR_ERR(rdev));
3238 			return PTR_ERR(rdev);
3239 		}
3240 		/* set save_raid_disk if appropriate */
3241 		if (!mddev->persistent) {
3242 			if (info->state & (1<<MD_DISK_SYNC)  &&
3243 			    info->raid_disk < mddev->raid_disks)
3244 				rdev->raid_disk = info->raid_disk;
3245 			else
3246 				rdev->raid_disk = -1;
3247 		} else
3248 			super_types[mddev->major_version].
3249 				validate_super(mddev, rdev);
3250 		rdev->saved_raid_disk = rdev->raid_disk;
3251 
3252 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
3253 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3254 			set_bit(WriteMostly, &rdev->flags);
3255 
3256 		rdev->raid_disk = -1;
3257 		err = bind_rdev_to_array(rdev, mddev);
3258 		if (err)
3259 			export_rdev(rdev);
3260 
3261 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3262 		md_wakeup_thread(mddev->thread);
3263 		return err;
3264 	}
3265 
3266 	/* otherwise, add_new_disk is only allowed
3267 	 * for major_version==0 superblocks
3268 	 */
3269 	if (mddev->major_version != 0) {
3270 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
3271 		       mdname(mddev));
3272 		return -EINVAL;
3273 	}
3274 
3275 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
3276 		int err;
3277 		rdev = md_import_device (dev, -1, 0);
3278 		if (IS_ERR(rdev)) {
3279 			printk(KERN_WARNING
3280 				"md: error, md_import_device() returned %ld\n",
3281 				PTR_ERR(rdev));
3282 			return PTR_ERR(rdev);
3283 		}
3284 		rdev->desc_nr = info->number;
3285 		if (info->raid_disk < mddev->raid_disks)
3286 			rdev->raid_disk = info->raid_disk;
3287 		else
3288 			rdev->raid_disk = -1;
3289 
3290 		rdev->flags = 0;
3291 
3292 		if (rdev->raid_disk < mddev->raid_disks)
3293 			if (info->state & (1<<MD_DISK_SYNC))
3294 				set_bit(In_sync, &rdev->flags);
3295 
3296 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3297 			set_bit(WriteMostly, &rdev->flags);
3298 
3299 		if (!mddev->persistent) {
3300 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
3301 			rdev->sb_offset = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
3302 		} else
3303 			rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
3304 		rdev->size = calc_dev_size(rdev, mddev->chunk_size);
3305 
3306 		err = bind_rdev_to_array(rdev, mddev);
3307 		if (err) {
3308 			export_rdev(rdev);
3309 			return err;
3310 		}
3311 	}
3312 
3313 	return 0;
3314 }
3315 
3316 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
3317 {
3318 	char b[BDEVNAME_SIZE];
3319 	mdk_rdev_t *rdev;
3320 
3321 	if (!mddev->pers)
3322 		return -ENODEV;
3323 
3324 	rdev = find_rdev(mddev, dev);
3325 	if (!rdev)
3326 		return -ENXIO;
3327 
3328 	if (rdev->raid_disk >= 0)
3329 		goto busy;
3330 
3331 	kick_rdev_from_array(rdev);
3332 	md_update_sb(mddev);
3333 	md_new_event(mddev);
3334 
3335 	return 0;
3336 busy:
3337 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ... \n",
3338 		bdevname(rdev->bdev,b), mdname(mddev));
3339 	return -EBUSY;
3340 }
3341 
3342 static int hot_add_disk(mddev_t * mddev, dev_t dev)
3343 {
3344 	char b[BDEVNAME_SIZE];
3345 	int err;
3346 	unsigned int size;
3347 	mdk_rdev_t *rdev;
3348 
3349 	if (!mddev->pers)
3350 		return -ENODEV;
3351 
3352 	if (mddev->major_version != 0) {
3353 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
3354 			" version-0 superblocks.\n",
3355 			mdname(mddev));
3356 		return -EINVAL;
3357 	}
3358 	if (!mddev->pers->hot_add_disk) {
3359 		printk(KERN_WARNING
3360 			"%s: personality does not support diskops!\n",
3361 			mdname(mddev));
3362 		return -EINVAL;
3363 	}
3364 
3365 	rdev = md_import_device (dev, -1, 0);
3366 	if (IS_ERR(rdev)) {
3367 		printk(KERN_WARNING
3368 			"md: error, md_import_device() returned %ld\n",
3369 			PTR_ERR(rdev));
3370 		return -EINVAL;
3371 	}
3372 
3373 	if (mddev->persistent)
3374 		rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
3375 	else
3376 		rdev->sb_offset =
3377 			rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
3378 
3379 	size = calc_dev_size(rdev, mddev->chunk_size);
3380 	rdev->size = size;
3381 
3382 	if (test_bit(Faulty, &rdev->flags)) {
3383 		printk(KERN_WARNING
3384 			"md: can not hot-add faulty %s disk to %s!\n",
3385 			bdevname(rdev->bdev,b), mdname(mddev));
3386 		err = -EINVAL;
3387 		goto abort_export;
3388 	}
3389 	clear_bit(In_sync, &rdev->flags);
3390 	rdev->desc_nr = -1;
3391 	err = bind_rdev_to_array(rdev, mddev);
3392 	if (err)
3393 		goto abort_export;
3394 
3395 	/*
3396 	 * The rest should better be atomic, we can have disk failures
3397 	 * noticed in interrupt contexts ...
3398 	 */
3399 
3400 	if (rdev->desc_nr == mddev->max_disks) {
3401 		printk(KERN_WARNING "%s: can not hot-add to full array!\n",
3402 			mdname(mddev));
3403 		err = -EBUSY;
3404 		goto abort_unbind_export;
3405 	}
3406 
3407 	rdev->raid_disk = -1;
3408 
3409 	md_update_sb(mddev);
3410 
3411 	/*
3412 	 * Kick recovery, maybe this spare has to be added to the
3413 	 * array immediately.
3414 	 */
3415 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3416 	md_wakeup_thread(mddev->thread);
3417 	md_new_event(mddev);
3418 	return 0;
3419 
3420 abort_unbind_export:
3421 	unbind_rdev_from_array(rdev);
3422 
3423 abort_export:
3424 	export_rdev(rdev);
3425 	return err;
3426 }
3427 
3428 /* similar to deny_write_access, but accounts for our holding a reference
3429  * to the file ourselves */
3430 static int deny_bitmap_write_access(struct file * file)
3431 {
3432 	struct inode *inode = file->f_mapping->host;
3433 
3434 	spin_lock(&inode->i_lock);
3435 	if (atomic_read(&inode->i_writecount) > 1) {
3436 		spin_unlock(&inode->i_lock);
3437 		return -ETXTBSY;
3438 	}
3439 	atomic_set(&inode->i_writecount, -1);
3440 	spin_unlock(&inode->i_lock);
3441 
3442 	return 0;
3443 }
3444 
3445 static int set_bitmap_file(mddev_t *mddev, int fd)
3446 {
3447 	int err;
3448 
3449 	if (mddev->pers) {
3450 		if (!mddev->pers->quiesce)
3451 			return -EBUSY;
3452 		if (mddev->recovery || mddev->sync_thread)
3453 			return -EBUSY;
3454 		/* we should be able to change the bitmap.. */
3455 	}
3456 
3457 
3458 	if (fd >= 0) {
3459 		if (mddev->bitmap)
3460 			return -EEXIST; /* cannot add when bitmap is present */
3461 		mddev->bitmap_file = fget(fd);
3462 
3463 		if (mddev->bitmap_file == NULL) {
3464 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
3465 			       mdname(mddev));
3466 			return -EBADF;
3467 		}
3468 
3469 		err = deny_bitmap_write_access(mddev->bitmap_file);
3470 		if (err) {
3471 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
3472 			       mdname(mddev));
3473 			fput(mddev->bitmap_file);
3474 			mddev->bitmap_file = NULL;
3475 			return err;
3476 		}
3477 		mddev->bitmap_offset = 0; /* file overrides offset */
3478 	} else if (mddev->bitmap == NULL)
3479 		return -ENOENT; /* cannot remove what isn't there */
3480 	err = 0;
3481 	if (mddev->pers) {
3482 		mddev->pers->quiesce(mddev, 1);
3483 		if (fd >= 0)
3484 			err = bitmap_create(mddev);
3485 		if (fd < 0 || err)
3486 			bitmap_destroy(mddev);
3487 		mddev->pers->quiesce(mddev, 0);
3488 	} else if (fd < 0) {
3489 		if (mddev->bitmap_file)
3490 			fput(mddev->bitmap_file);
3491 		mddev->bitmap_file = NULL;
3492 	}
3493 
3494 	return err;
3495 }
3496 
3497 /*
3498  * set_array_info is used two different ways
3499  * The original usage is when creating a new array.
3500  * In this usage, raid_disks is > 0 and it together with
3501  *  level, size, not_persistent,layout,chunksize determine the
3502  *  shape of the array.
3503  *  This will always create an array with a type-0.90.0 superblock.
3504  * The newer usage is when assembling an array.
3505  *  In this case raid_disks will be 0, and the major_version field is
3506  *  use to determine which style super-blocks are to be found on the devices.
3507  *  The minor and patch _version numbers are also kept incase the
3508  *  super_block handler wishes to interpret them.
3509  */
3510 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
3511 {
3512 
3513 	if (info->raid_disks == 0) {
3514 		/* just setting version number for superblock loading */
3515 		if (info->major_version < 0 ||
3516 		    info->major_version >= sizeof(super_types)/sizeof(super_types[0]) ||
3517 		    super_types[info->major_version].name == NULL) {
3518 			/* maybe try to auto-load a module? */
3519 			printk(KERN_INFO
3520 				"md: superblock version %d not known\n",
3521 				info->major_version);
3522 			return -EINVAL;
3523 		}
3524 		mddev->major_version = info->major_version;
3525 		mddev->minor_version = info->minor_version;
3526 		mddev->patch_version = info->patch_version;
3527 		return 0;
3528 	}
3529 	mddev->major_version = MD_MAJOR_VERSION;
3530 	mddev->minor_version = MD_MINOR_VERSION;
3531 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
3532 	mddev->ctime         = get_seconds();
3533 
3534 	mddev->level         = info->level;
3535 	mddev->clevel[0]     = 0;
3536 	mddev->size          = info->size;
3537 	mddev->raid_disks    = info->raid_disks;
3538 	/* don't set md_minor, it is determined by which /dev/md* was
3539 	 * openned
3540 	 */
3541 	if (info->state & (1<<MD_SB_CLEAN))
3542 		mddev->recovery_cp = MaxSector;
3543 	else
3544 		mddev->recovery_cp = 0;
3545 	mddev->persistent    = ! info->not_persistent;
3546 
3547 	mddev->layout        = info->layout;
3548 	mddev->chunk_size    = info->chunk_size;
3549 
3550 	mddev->max_disks     = MD_SB_DISKS;
3551 
3552 	mddev->sb_dirty      = 1;
3553 
3554 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
3555 	mddev->bitmap_offset = 0;
3556 
3557 	mddev->reshape_position = MaxSector;
3558 
3559 	/*
3560 	 * Generate a 128 bit UUID
3561 	 */
3562 	get_random_bytes(mddev->uuid, 16);
3563 
3564 	mddev->new_level = mddev->level;
3565 	mddev->new_chunk = mddev->chunk_size;
3566 	mddev->new_layout = mddev->layout;
3567 	mddev->delta_disks = 0;
3568 
3569 	return 0;
3570 }
3571 
3572 static int update_size(mddev_t *mddev, unsigned long size)
3573 {
3574 	mdk_rdev_t * rdev;
3575 	int rv;
3576 	struct list_head *tmp;
3577 	int fit = (size == 0);
3578 
3579 	if (mddev->pers->resize == NULL)
3580 		return -EINVAL;
3581 	/* The "size" is the amount of each device that is used.
3582 	 * This can only make sense for arrays with redundancy.
3583 	 * linear and raid0 always use whatever space is available
3584 	 * We can only consider changing the size if no resync
3585 	 * or reconstruction is happening, and if the new size
3586 	 * is acceptable. It must fit before the sb_offset or,
3587 	 * if that is <data_offset, it must fit before the
3588 	 * size of each device.
3589 	 * If size is zero, we find the largest size that fits.
3590 	 */
3591 	if (mddev->sync_thread)
3592 		return -EBUSY;
3593 	ITERATE_RDEV(mddev,rdev,tmp) {
3594 		sector_t avail;
3595 		if (rdev->sb_offset > rdev->data_offset)
3596 			avail = (rdev->sb_offset*2) - rdev->data_offset;
3597 		else
3598 			avail = get_capacity(rdev->bdev->bd_disk)
3599 				- rdev->data_offset;
3600 		if (fit && (size == 0 || size > avail/2))
3601 			size = avail/2;
3602 		if (avail < ((sector_t)size << 1))
3603 			return -ENOSPC;
3604 	}
3605 	rv = mddev->pers->resize(mddev, (sector_t)size *2);
3606 	if (!rv) {
3607 		struct block_device *bdev;
3608 
3609 		bdev = bdget_disk(mddev->gendisk, 0);
3610 		if (bdev) {
3611 			mutex_lock(&bdev->bd_inode->i_mutex);
3612 			i_size_write(bdev->bd_inode, (loff_t)mddev->array_size << 10);
3613 			mutex_unlock(&bdev->bd_inode->i_mutex);
3614 			bdput(bdev);
3615 		}
3616 	}
3617 	return rv;
3618 }
3619 
3620 static int update_raid_disks(mddev_t *mddev, int raid_disks)
3621 {
3622 	int rv;
3623 	/* change the number of raid disks */
3624 	if (mddev->pers->check_reshape == NULL)
3625 		return -EINVAL;
3626 	if (raid_disks <= 0 ||
3627 	    raid_disks >= mddev->max_disks)
3628 		return -EINVAL;
3629 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
3630 		return -EBUSY;
3631 	mddev->delta_disks = raid_disks - mddev->raid_disks;
3632 
3633 	rv = mddev->pers->check_reshape(mddev);
3634 	return rv;
3635 }
3636 
3637 
3638 /*
3639  * update_array_info is used to change the configuration of an
3640  * on-line array.
3641  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
3642  * fields in the info are checked against the array.
3643  * Any differences that cannot be handled will cause an error.
3644  * Normally, only one change can be managed at a time.
3645  */
3646 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
3647 {
3648 	int rv = 0;
3649 	int cnt = 0;
3650 	int state = 0;
3651 
3652 	/* calculate expected state,ignoring low bits */
3653 	if (mddev->bitmap && mddev->bitmap_offset)
3654 		state |= (1 << MD_SB_BITMAP_PRESENT);
3655 
3656 	if (mddev->major_version != info->major_version ||
3657 	    mddev->minor_version != info->minor_version ||
3658 /*	    mddev->patch_version != info->patch_version || */
3659 	    mddev->ctime         != info->ctime         ||
3660 	    mddev->level         != info->level         ||
3661 /*	    mddev->layout        != info->layout        || */
3662 	    !mddev->persistent	 != info->not_persistent||
3663 	    mddev->chunk_size    != info->chunk_size    ||
3664 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
3665 	    ((state^info->state) & 0xfffffe00)
3666 		)
3667 		return -EINVAL;
3668 	/* Check there is only one change */
3669 	if (info->size >= 0 && mddev->size != info->size) cnt++;
3670 	if (mddev->raid_disks != info->raid_disks) cnt++;
3671 	if (mddev->layout != info->layout) cnt++;
3672 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
3673 	if (cnt == 0) return 0;
3674 	if (cnt > 1) return -EINVAL;
3675 
3676 	if (mddev->layout != info->layout) {
3677 		/* Change layout
3678 		 * we don't need to do anything at the md level, the
3679 		 * personality will take care of it all.
3680 		 */
3681 		if (mddev->pers->reconfig == NULL)
3682 			return -EINVAL;
3683 		else
3684 			return mddev->pers->reconfig(mddev, info->layout, -1);
3685 	}
3686 	if (info->size >= 0 && mddev->size != info->size)
3687 		rv = update_size(mddev, info->size);
3688 
3689 	if (mddev->raid_disks    != info->raid_disks)
3690 		rv = update_raid_disks(mddev, info->raid_disks);
3691 
3692 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
3693 		if (mddev->pers->quiesce == NULL)
3694 			return -EINVAL;
3695 		if (mddev->recovery || mddev->sync_thread)
3696 			return -EBUSY;
3697 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
3698 			/* add the bitmap */
3699 			if (mddev->bitmap)
3700 				return -EEXIST;
3701 			if (mddev->default_bitmap_offset == 0)
3702 				return -EINVAL;
3703 			mddev->bitmap_offset = mddev->default_bitmap_offset;
3704 			mddev->pers->quiesce(mddev, 1);
3705 			rv = bitmap_create(mddev);
3706 			if (rv)
3707 				bitmap_destroy(mddev);
3708 			mddev->pers->quiesce(mddev, 0);
3709 		} else {
3710 			/* remove the bitmap */
3711 			if (!mddev->bitmap)
3712 				return -ENOENT;
3713 			if (mddev->bitmap->file)
3714 				return -EINVAL;
3715 			mddev->pers->quiesce(mddev, 1);
3716 			bitmap_destroy(mddev);
3717 			mddev->pers->quiesce(mddev, 0);
3718 			mddev->bitmap_offset = 0;
3719 		}
3720 	}
3721 	md_update_sb(mddev);
3722 	return rv;
3723 }
3724 
3725 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
3726 {
3727 	mdk_rdev_t *rdev;
3728 
3729 	if (mddev->pers == NULL)
3730 		return -ENODEV;
3731 
3732 	rdev = find_rdev(mddev, dev);
3733 	if (!rdev)
3734 		return -ENODEV;
3735 
3736 	md_error(mddev, rdev);
3737 	return 0;
3738 }
3739 
3740 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3741 {
3742 	mddev_t *mddev = bdev->bd_disk->private_data;
3743 
3744 	geo->heads = 2;
3745 	geo->sectors = 4;
3746 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
3747 	return 0;
3748 }
3749 
3750 static int md_ioctl(struct inode *inode, struct file *file,
3751 			unsigned int cmd, unsigned long arg)
3752 {
3753 	int err = 0;
3754 	void __user *argp = (void __user *)arg;
3755 	mddev_t *mddev = NULL;
3756 
3757 	if (!capable(CAP_SYS_ADMIN))
3758 		return -EACCES;
3759 
3760 	/*
3761 	 * Commands dealing with the RAID driver but not any
3762 	 * particular array:
3763 	 */
3764 	switch (cmd)
3765 	{
3766 		case RAID_VERSION:
3767 			err = get_version(argp);
3768 			goto done;
3769 
3770 		case PRINT_RAID_DEBUG:
3771 			err = 0;
3772 			md_print_devices();
3773 			goto done;
3774 
3775 #ifndef MODULE
3776 		case RAID_AUTORUN:
3777 			err = 0;
3778 			autostart_arrays(arg);
3779 			goto done;
3780 #endif
3781 		default:;
3782 	}
3783 
3784 	/*
3785 	 * Commands creating/starting a new array:
3786 	 */
3787 
3788 	mddev = inode->i_bdev->bd_disk->private_data;
3789 
3790 	if (!mddev) {
3791 		BUG();
3792 		goto abort;
3793 	}
3794 
3795 
3796 	if (cmd == START_ARRAY) {
3797 		/* START_ARRAY doesn't need to lock the array as autostart_array
3798 		 * does the locking, and it could even be a different array
3799 		 */
3800 		static int cnt = 3;
3801 		if (cnt > 0 ) {
3802 			printk(KERN_WARNING
3803 			       "md: %s(pid %d) used deprecated START_ARRAY ioctl. "
3804 			       "This will not be supported beyond July 2006\n",
3805 			       current->comm, current->pid);
3806 			cnt--;
3807 		}
3808 		err = autostart_array(new_decode_dev(arg));
3809 		if (err) {
3810 			printk(KERN_WARNING "md: autostart failed!\n");
3811 			goto abort;
3812 		}
3813 		goto done;
3814 	}
3815 
3816 	err = mddev_lock(mddev);
3817 	if (err) {
3818 		printk(KERN_INFO
3819 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
3820 			err, cmd);
3821 		goto abort;
3822 	}
3823 
3824 	switch (cmd)
3825 	{
3826 		case SET_ARRAY_INFO:
3827 			{
3828 				mdu_array_info_t info;
3829 				if (!arg)
3830 					memset(&info, 0, sizeof(info));
3831 				else if (copy_from_user(&info, argp, sizeof(info))) {
3832 					err = -EFAULT;
3833 					goto abort_unlock;
3834 				}
3835 				if (mddev->pers) {
3836 					err = update_array_info(mddev, &info);
3837 					if (err) {
3838 						printk(KERN_WARNING "md: couldn't update"
3839 						       " array info. %d\n", err);
3840 						goto abort_unlock;
3841 					}
3842 					goto done_unlock;
3843 				}
3844 				if (!list_empty(&mddev->disks)) {
3845 					printk(KERN_WARNING
3846 					       "md: array %s already has disks!\n",
3847 					       mdname(mddev));
3848 					err = -EBUSY;
3849 					goto abort_unlock;
3850 				}
3851 				if (mddev->raid_disks) {
3852 					printk(KERN_WARNING
3853 					       "md: array %s already initialised!\n",
3854 					       mdname(mddev));
3855 					err = -EBUSY;
3856 					goto abort_unlock;
3857 				}
3858 				err = set_array_info(mddev, &info);
3859 				if (err) {
3860 					printk(KERN_WARNING "md: couldn't set"
3861 					       " array info. %d\n", err);
3862 					goto abort_unlock;
3863 				}
3864 			}
3865 			goto done_unlock;
3866 
3867 		default:;
3868 	}
3869 
3870 	/*
3871 	 * Commands querying/configuring an existing array:
3872 	 */
3873 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
3874 	 * RUN_ARRAY, and SET_BITMAP_FILE are allowed */
3875 	if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
3876 			&& cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE) {
3877 		err = -ENODEV;
3878 		goto abort_unlock;
3879 	}
3880 
3881 	/*
3882 	 * Commands even a read-only array can execute:
3883 	 */
3884 	switch (cmd)
3885 	{
3886 		case GET_ARRAY_INFO:
3887 			err = get_array_info(mddev, argp);
3888 			goto done_unlock;
3889 
3890 		case GET_BITMAP_FILE:
3891 			err = get_bitmap_file(mddev, argp);
3892 			goto done_unlock;
3893 
3894 		case GET_DISK_INFO:
3895 			err = get_disk_info(mddev, argp);
3896 			goto done_unlock;
3897 
3898 		case RESTART_ARRAY_RW:
3899 			err = restart_array(mddev);
3900 			goto done_unlock;
3901 
3902 		case STOP_ARRAY:
3903 			err = do_md_stop (mddev, 0);
3904 			goto done_unlock;
3905 
3906 		case STOP_ARRAY_RO:
3907 			err = do_md_stop (mddev, 1);
3908 			goto done_unlock;
3909 
3910 	/*
3911 	 * We have a problem here : there is no easy way to give a CHS
3912 	 * virtual geometry. We currently pretend that we have a 2 heads
3913 	 * 4 sectors (with a BIG number of cylinders...). This drives
3914 	 * dosfs just mad... ;-)
3915 	 */
3916 	}
3917 
3918 	/*
3919 	 * The remaining ioctls are changing the state of the
3920 	 * superblock, so we do not allow them on read-only arrays.
3921 	 * However non-MD ioctls (e.g. get-size) will still come through
3922 	 * here and hit the 'default' below, so only disallow
3923 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
3924 	 */
3925 	if (_IOC_TYPE(cmd) == MD_MAJOR &&
3926 	    mddev->ro && mddev->pers) {
3927 		if (mddev->ro == 2) {
3928 			mddev->ro = 0;
3929 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3930 		md_wakeup_thread(mddev->thread);
3931 
3932 		} else {
3933 			err = -EROFS;
3934 			goto abort_unlock;
3935 		}
3936 	}
3937 
3938 	switch (cmd)
3939 	{
3940 		case ADD_NEW_DISK:
3941 		{
3942 			mdu_disk_info_t info;
3943 			if (copy_from_user(&info, argp, sizeof(info)))
3944 				err = -EFAULT;
3945 			else
3946 				err = add_new_disk(mddev, &info);
3947 			goto done_unlock;
3948 		}
3949 
3950 		case HOT_REMOVE_DISK:
3951 			err = hot_remove_disk(mddev, new_decode_dev(arg));
3952 			goto done_unlock;
3953 
3954 		case HOT_ADD_DISK:
3955 			err = hot_add_disk(mddev, new_decode_dev(arg));
3956 			goto done_unlock;
3957 
3958 		case SET_DISK_FAULTY:
3959 			err = set_disk_faulty(mddev, new_decode_dev(arg));
3960 			goto done_unlock;
3961 
3962 		case RUN_ARRAY:
3963 			err = do_md_run (mddev);
3964 			goto done_unlock;
3965 
3966 		case SET_BITMAP_FILE:
3967 			err = set_bitmap_file(mddev, (int)arg);
3968 			goto done_unlock;
3969 
3970 		default:
3971 			if (_IOC_TYPE(cmd) == MD_MAJOR)
3972 				printk(KERN_WARNING "md: %s(pid %d) used"
3973 					" obsolete MD ioctl, upgrade your"
3974 					" software to use new ictls.\n",
3975 					current->comm, current->pid);
3976 			err = -EINVAL;
3977 			goto abort_unlock;
3978 	}
3979 
3980 done_unlock:
3981 abort_unlock:
3982 	mddev_unlock(mddev);
3983 
3984 	return err;
3985 done:
3986 	if (err)
3987 		MD_BUG();
3988 abort:
3989 	return err;
3990 }
3991 
3992 static int md_open(struct inode *inode, struct file *file)
3993 {
3994 	/*
3995 	 * Succeed if we can lock the mddev, which confirms that
3996 	 * it isn't being stopped right now.
3997 	 */
3998 	mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
3999 	int err;
4000 
4001 	if ((err = mddev_lock(mddev)))
4002 		goto out;
4003 
4004 	err = 0;
4005 	mddev_get(mddev);
4006 	mddev_unlock(mddev);
4007 
4008 	check_disk_change(inode->i_bdev);
4009  out:
4010 	return err;
4011 }
4012 
4013 static int md_release(struct inode *inode, struct file * file)
4014 {
4015  	mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
4016 
4017 	if (!mddev)
4018 		BUG();
4019 	mddev_put(mddev);
4020 
4021 	return 0;
4022 }
4023 
4024 static int md_media_changed(struct gendisk *disk)
4025 {
4026 	mddev_t *mddev = disk->private_data;
4027 
4028 	return mddev->changed;
4029 }
4030 
4031 static int md_revalidate(struct gendisk *disk)
4032 {
4033 	mddev_t *mddev = disk->private_data;
4034 
4035 	mddev->changed = 0;
4036 	return 0;
4037 }
4038 static struct block_device_operations md_fops =
4039 {
4040 	.owner		= THIS_MODULE,
4041 	.open		= md_open,
4042 	.release	= md_release,
4043 	.ioctl		= md_ioctl,
4044 	.getgeo		= md_getgeo,
4045 	.media_changed	= md_media_changed,
4046 	.revalidate_disk= md_revalidate,
4047 };
4048 
4049 static int md_thread(void * arg)
4050 {
4051 	mdk_thread_t *thread = arg;
4052 
4053 	/*
4054 	 * md_thread is a 'system-thread', it's priority should be very
4055 	 * high. We avoid resource deadlocks individually in each
4056 	 * raid personality. (RAID5 does preallocation) We also use RR and
4057 	 * the very same RT priority as kswapd, thus we will never get
4058 	 * into a priority inversion deadlock.
4059 	 *
4060 	 * we definitely have to have equal or higher priority than
4061 	 * bdflush, otherwise bdflush will deadlock if there are too
4062 	 * many dirty RAID5 blocks.
4063 	 */
4064 
4065 	allow_signal(SIGKILL);
4066 	while (!kthread_should_stop()) {
4067 
4068 		/* We need to wait INTERRUPTIBLE so that
4069 		 * we don't add to the load-average.
4070 		 * That means we need to be sure no signals are
4071 		 * pending
4072 		 */
4073 		if (signal_pending(current))
4074 			flush_signals(current);
4075 
4076 		wait_event_interruptible_timeout
4077 			(thread->wqueue,
4078 			 test_bit(THREAD_WAKEUP, &thread->flags)
4079 			 || kthread_should_stop(),
4080 			 thread->timeout);
4081 		try_to_freeze();
4082 
4083 		clear_bit(THREAD_WAKEUP, &thread->flags);
4084 
4085 		thread->run(thread->mddev);
4086 	}
4087 
4088 	return 0;
4089 }
4090 
4091 void md_wakeup_thread(mdk_thread_t *thread)
4092 {
4093 	if (thread) {
4094 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
4095 		set_bit(THREAD_WAKEUP, &thread->flags);
4096 		wake_up(&thread->wqueue);
4097 	}
4098 }
4099 
4100 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
4101 				 const char *name)
4102 {
4103 	mdk_thread_t *thread;
4104 
4105 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
4106 	if (!thread)
4107 		return NULL;
4108 
4109 	init_waitqueue_head(&thread->wqueue);
4110 
4111 	thread->run = run;
4112 	thread->mddev = mddev;
4113 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
4114 	thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
4115 	if (IS_ERR(thread->tsk)) {
4116 		kfree(thread);
4117 		return NULL;
4118 	}
4119 	return thread;
4120 }
4121 
4122 void md_unregister_thread(mdk_thread_t *thread)
4123 {
4124 	dprintk("interrupting MD-thread pid %d\n", thread->tsk->pid);
4125 
4126 	kthread_stop(thread->tsk);
4127 	kfree(thread);
4128 }
4129 
4130 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
4131 {
4132 	if (!mddev) {
4133 		MD_BUG();
4134 		return;
4135 	}
4136 
4137 	if (!rdev || test_bit(Faulty, &rdev->flags))
4138 		return;
4139 /*
4140 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
4141 		mdname(mddev),
4142 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
4143 		__builtin_return_address(0),__builtin_return_address(1),
4144 		__builtin_return_address(2),__builtin_return_address(3));
4145 */
4146 	if (!mddev->pers->error_handler)
4147 		return;
4148 	mddev->pers->error_handler(mddev,rdev);
4149 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4150 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4151 	md_wakeup_thread(mddev->thread);
4152 	md_new_event(mddev);
4153 }
4154 
4155 /* seq_file implementation /proc/mdstat */
4156 
4157 static void status_unused(struct seq_file *seq)
4158 {
4159 	int i = 0;
4160 	mdk_rdev_t *rdev;
4161 	struct list_head *tmp;
4162 
4163 	seq_printf(seq, "unused devices: ");
4164 
4165 	ITERATE_RDEV_PENDING(rdev,tmp) {
4166 		char b[BDEVNAME_SIZE];
4167 		i++;
4168 		seq_printf(seq, "%s ",
4169 			      bdevname(rdev->bdev,b));
4170 	}
4171 	if (!i)
4172 		seq_printf(seq, "<none>");
4173 
4174 	seq_printf(seq, "\n");
4175 }
4176 
4177 
4178 static void status_resync(struct seq_file *seq, mddev_t * mddev)
4179 {
4180 	sector_t max_blocks, resync, res;
4181 	unsigned long dt, db, rt;
4182 	int scale;
4183 	unsigned int per_milli;
4184 
4185 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
4186 
4187 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4188 		max_blocks = mddev->resync_max_sectors >> 1;
4189 	else
4190 		max_blocks = mddev->size;
4191 
4192 	/*
4193 	 * Should not happen.
4194 	 */
4195 	if (!max_blocks) {
4196 		MD_BUG();
4197 		return;
4198 	}
4199 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
4200 	 * in a sector_t, and (max_blocks>>scale) will fit in a
4201 	 * u32, as those are the requirements for sector_div.
4202 	 * Thus 'scale' must be at least 10
4203 	 */
4204 	scale = 10;
4205 	if (sizeof(sector_t) > sizeof(unsigned long)) {
4206 		while ( max_blocks/2 > (1ULL<<(scale+32)))
4207 			scale++;
4208 	}
4209 	res = (resync>>scale)*1000;
4210 	sector_div(res, (u32)((max_blocks>>scale)+1));
4211 
4212 	per_milli = res;
4213 	{
4214 		int i, x = per_milli/50, y = 20-x;
4215 		seq_printf(seq, "[");
4216 		for (i = 0; i < x; i++)
4217 			seq_printf(seq, "=");
4218 		seq_printf(seq, ">");
4219 		for (i = 0; i < y; i++)
4220 			seq_printf(seq, ".");
4221 		seq_printf(seq, "] ");
4222 	}
4223 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
4224 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
4225 		    "reshape" :
4226 		      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
4227 		       "resync" : "recovery")),
4228 		      per_milli/10, per_milli % 10,
4229 		   (unsigned long long) resync,
4230 		   (unsigned long long) max_blocks);
4231 
4232 	/*
4233 	 * We do not want to overflow, so the order of operands and
4234 	 * the * 100 / 100 trick are important. We do a +1 to be
4235 	 * safe against division by zero. We only estimate anyway.
4236 	 *
4237 	 * dt: time from mark until now
4238 	 * db: blocks written from mark until now
4239 	 * rt: remaining time
4240 	 */
4241 	dt = ((jiffies - mddev->resync_mark) / HZ);
4242 	if (!dt) dt++;
4243 	db = resync - (mddev->resync_mark_cnt/2);
4244 	rt = (dt * ((unsigned long)(max_blocks-resync) / (db/100+1)))/100;
4245 
4246 	seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
4247 
4248 	seq_printf(seq, " speed=%ldK/sec", db/dt);
4249 }
4250 
4251 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
4252 {
4253 	struct list_head *tmp;
4254 	loff_t l = *pos;
4255 	mddev_t *mddev;
4256 
4257 	if (l >= 0x10000)
4258 		return NULL;
4259 	if (!l--)
4260 		/* header */
4261 		return (void*)1;
4262 
4263 	spin_lock(&all_mddevs_lock);
4264 	list_for_each(tmp,&all_mddevs)
4265 		if (!l--) {
4266 			mddev = list_entry(tmp, mddev_t, all_mddevs);
4267 			mddev_get(mddev);
4268 			spin_unlock(&all_mddevs_lock);
4269 			return mddev;
4270 		}
4271 	spin_unlock(&all_mddevs_lock);
4272 	if (!l--)
4273 		return (void*)2;/* tail */
4274 	return NULL;
4275 }
4276 
4277 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4278 {
4279 	struct list_head *tmp;
4280 	mddev_t *next_mddev, *mddev = v;
4281 
4282 	++*pos;
4283 	if (v == (void*)2)
4284 		return NULL;
4285 
4286 	spin_lock(&all_mddevs_lock);
4287 	if (v == (void*)1)
4288 		tmp = all_mddevs.next;
4289 	else
4290 		tmp = mddev->all_mddevs.next;
4291 	if (tmp != &all_mddevs)
4292 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
4293 	else {
4294 		next_mddev = (void*)2;
4295 		*pos = 0x10000;
4296 	}
4297 	spin_unlock(&all_mddevs_lock);
4298 
4299 	if (v != (void*)1)
4300 		mddev_put(mddev);
4301 	return next_mddev;
4302 
4303 }
4304 
4305 static void md_seq_stop(struct seq_file *seq, void *v)
4306 {
4307 	mddev_t *mddev = v;
4308 
4309 	if (mddev && v != (void*)1 && v != (void*)2)
4310 		mddev_put(mddev);
4311 }
4312 
4313 struct mdstat_info {
4314 	int event;
4315 };
4316 
4317 static int md_seq_show(struct seq_file *seq, void *v)
4318 {
4319 	mddev_t *mddev = v;
4320 	sector_t size;
4321 	struct list_head *tmp2;
4322 	mdk_rdev_t *rdev;
4323 	struct mdstat_info *mi = seq->private;
4324 	struct bitmap *bitmap;
4325 
4326 	if (v == (void*)1) {
4327 		struct mdk_personality *pers;
4328 		seq_printf(seq, "Personalities : ");
4329 		spin_lock(&pers_lock);
4330 		list_for_each_entry(pers, &pers_list, list)
4331 			seq_printf(seq, "[%s] ", pers->name);
4332 
4333 		spin_unlock(&pers_lock);
4334 		seq_printf(seq, "\n");
4335 		mi->event = atomic_read(&md_event_count);
4336 		return 0;
4337 	}
4338 	if (v == (void*)2) {
4339 		status_unused(seq);
4340 		return 0;
4341 	}
4342 
4343 	if (mddev_lock(mddev)!=0)
4344 		return -EINTR;
4345 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
4346 		seq_printf(seq, "%s : %sactive", mdname(mddev),
4347 						mddev->pers ? "" : "in");
4348 		if (mddev->pers) {
4349 			if (mddev->ro==1)
4350 				seq_printf(seq, " (read-only)");
4351 			if (mddev->ro==2)
4352 				seq_printf(seq, "(auto-read-only)");
4353 			seq_printf(seq, " %s", mddev->pers->name);
4354 		}
4355 
4356 		size = 0;
4357 		ITERATE_RDEV(mddev,rdev,tmp2) {
4358 			char b[BDEVNAME_SIZE];
4359 			seq_printf(seq, " %s[%d]",
4360 				bdevname(rdev->bdev,b), rdev->desc_nr);
4361 			if (test_bit(WriteMostly, &rdev->flags))
4362 				seq_printf(seq, "(W)");
4363 			if (test_bit(Faulty, &rdev->flags)) {
4364 				seq_printf(seq, "(F)");
4365 				continue;
4366 			} else if (rdev->raid_disk < 0)
4367 				seq_printf(seq, "(S)"); /* spare */
4368 			size += rdev->size;
4369 		}
4370 
4371 		if (!list_empty(&mddev->disks)) {
4372 			if (mddev->pers)
4373 				seq_printf(seq, "\n      %llu blocks",
4374 					(unsigned long long)mddev->array_size);
4375 			else
4376 				seq_printf(seq, "\n      %llu blocks",
4377 					(unsigned long long)size);
4378 		}
4379 		if (mddev->persistent) {
4380 			if (mddev->major_version != 0 ||
4381 			    mddev->minor_version != 90) {
4382 				seq_printf(seq," super %d.%d",
4383 					   mddev->major_version,
4384 					   mddev->minor_version);
4385 			}
4386 		} else
4387 			seq_printf(seq, " super non-persistent");
4388 
4389 		if (mddev->pers) {
4390 			mddev->pers->status (seq, mddev);
4391 	 		seq_printf(seq, "\n      ");
4392 			if (mddev->pers->sync_request) {
4393 				if (mddev->curr_resync > 2) {
4394 					status_resync (seq, mddev);
4395 					seq_printf(seq, "\n      ");
4396 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
4397 					seq_printf(seq, "\tresync=DELAYED\n      ");
4398 				else if (mddev->recovery_cp < MaxSector)
4399 					seq_printf(seq, "\tresync=PENDING\n      ");
4400 			}
4401 		} else
4402 			seq_printf(seq, "\n       ");
4403 
4404 		if ((bitmap = mddev->bitmap)) {
4405 			unsigned long chunk_kb;
4406 			unsigned long flags;
4407 			spin_lock_irqsave(&bitmap->lock, flags);
4408 			chunk_kb = bitmap->chunksize >> 10;
4409 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
4410 				"%lu%s chunk",
4411 				bitmap->pages - bitmap->missing_pages,
4412 				bitmap->pages,
4413 				(bitmap->pages - bitmap->missing_pages)
4414 					<< (PAGE_SHIFT - 10),
4415 				chunk_kb ? chunk_kb : bitmap->chunksize,
4416 				chunk_kb ? "KB" : "B");
4417 			if (bitmap->file) {
4418 				seq_printf(seq, ", file: ");
4419 				seq_path(seq, bitmap->file->f_vfsmnt,
4420 					 bitmap->file->f_dentry," \t\n");
4421 			}
4422 
4423 			seq_printf(seq, "\n");
4424 			spin_unlock_irqrestore(&bitmap->lock, flags);
4425 		}
4426 
4427 		seq_printf(seq, "\n");
4428 	}
4429 	mddev_unlock(mddev);
4430 
4431 	return 0;
4432 }
4433 
4434 static struct seq_operations md_seq_ops = {
4435 	.start  = md_seq_start,
4436 	.next   = md_seq_next,
4437 	.stop   = md_seq_stop,
4438 	.show   = md_seq_show,
4439 };
4440 
4441 static int md_seq_open(struct inode *inode, struct file *file)
4442 {
4443 	int error;
4444 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
4445 	if (mi == NULL)
4446 		return -ENOMEM;
4447 
4448 	error = seq_open(file, &md_seq_ops);
4449 	if (error)
4450 		kfree(mi);
4451 	else {
4452 		struct seq_file *p = file->private_data;
4453 		p->private = mi;
4454 		mi->event = atomic_read(&md_event_count);
4455 	}
4456 	return error;
4457 }
4458 
4459 static int md_seq_release(struct inode *inode, struct file *file)
4460 {
4461 	struct seq_file *m = file->private_data;
4462 	struct mdstat_info *mi = m->private;
4463 	m->private = NULL;
4464 	kfree(mi);
4465 	return seq_release(inode, file);
4466 }
4467 
4468 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
4469 {
4470 	struct seq_file *m = filp->private_data;
4471 	struct mdstat_info *mi = m->private;
4472 	int mask;
4473 
4474 	poll_wait(filp, &md_event_waiters, wait);
4475 
4476 	/* always allow read */
4477 	mask = POLLIN | POLLRDNORM;
4478 
4479 	if (mi->event != atomic_read(&md_event_count))
4480 		mask |= POLLERR | POLLPRI;
4481 	return mask;
4482 }
4483 
4484 static struct file_operations md_seq_fops = {
4485 	.open           = md_seq_open,
4486 	.read           = seq_read,
4487 	.llseek         = seq_lseek,
4488 	.release	= md_seq_release,
4489 	.poll		= mdstat_poll,
4490 };
4491 
4492 int register_md_personality(struct mdk_personality *p)
4493 {
4494 	spin_lock(&pers_lock);
4495 	list_add_tail(&p->list, &pers_list);
4496 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
4497 	spin_unlock(&pers_lock);
4498 	return 0;
4499 }
4500 
4501 int unregister_md_personality(struct mdk_personality *p)
4502 {
4503 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
4504 	spin_lock(&pers_lock);
4505 	list_del_init(&p->list);
4506 	spin_unlock(&pers_lock);
4507 	return 0;
4508 }
4509 
4510 static int is_mddev_idle(mddev_t *mddev)
4511 {
4512 	mdk_rdev_t * rdev;
4513 	struct list_head *tmp;
4514 	int idle;
4515 	unsigned long curr_events;
4516 
4517 	idle = 1;
4518 	ITERATE_RDEV(mddev,rdev,tmp) {
4519 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
4520 		curr_events = disk_stat_read(disk, sectors[0]) +
4521 				disk_stat_read(disk, sectors[1]) -
4522 				atomic_read(&disk->sync_io);
4523 		/* The difference between curr_events and last_events
4524 		 * will be affected by any new non-sync IO (making
4525 		 * curr_events bigger) and any difference in the amount of
4526 		 * in-flight syncio (making current_events bigger or smaller)
4527 		 * The amount in-flight is currently limited to
4528 		 * 32*64K in raid1/10 and 256*PAGE_SIZE in raid5/6
4529 		 * which is at most 4096 sectors.
4530 		 * These numbers are fairly fragile and should be made
4531 		 * more robust, probably by enforcing the
4532 		 * 'window size' that md_do_sync sort-of uses.
4533 		 *
4534 		 * Note: the following is an unsigned comparison.
4535 		 */
4536 		if ((curr_events - rdev->last_events + 4096) > 8192) {
4537 			rdev->last_events = curr_events;
4538 			idle = 0;
4539 		}
4540 	}
4541 	return idle;
4542 }
4543 
4544 void md_done_sync(mddev_t *mddev, int blocks, int ok)
4545 {
4546 	/* another "blocks" (512byte) blocks have been synced */
4547 	atomic_sub(blocks, &mddev->recovery_active);
4548 	wake_up(&mddev->recovery_wait);
4549 	if (!ok) {
4550 		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
4551 		md_wakeup_thread(mddev->thread);
4552 		// stop recovery, signal do_sync ....
4553 	}
4554 }
4555 
4556 
4557 /* md_write_start(mddev, bi)
4558  * If we need to update some array metadata (e.g. 'active' flag
4559  * in superblock) before writing, schedule a superblock update
4560  * and wait for it to complete.
4561  */
4562 void md_write_start(mddev_t *mddev, struct bio *bi)
4563 {
4564 	if (bio_data_dir(bi) != WRITE)
4565 		return;
4566 
4567 	BUG_ON(mddev->ro == 1);
4568 	if (mddev->ro == 2) {
4569 		/* need to switch to read/write */
4570 		mddev->ro = 0;
4571 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4572 		md_wakeup_thread(mddev->thread);
4573 	}
4574 	atomic_inc(&mddev->writes_pending);
4575 	if (mddev->in_sync) {
4576 		spin_lock_irq(&mddev->write_lock);
4577 		if (mddev->in_sync) {
4578 			mddev->in_sync = 0;
4579 			mddev->sb_dirty = 1;
4580 			md_wakeup_thread(mddev->thread);
4581 		}
4582 		spin_unlock_irq(&mddev->write_lock);
4583 	}
4584 	wait_event(mddev->sb_wait, mddev->sb_dirty==0);
4585 }
4586 
4587 void md_write_end(mddev_t *mddev)
4588 {
4589 	if (atomic_dec_and_test(&mddev->writes_pending)) {
4590 		if (mddev->safemode == 2)
4591 			md_wakeup_thread(mddev->thread);
4592 		else
4593 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
4594 	}
4595 }
4596 
4597 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
4598 
4599 #define SYNC_MARKS	10
4600 #define	SYNC_MARK_STEP	(3*HZ)
4601 void md_do_sync(mddev_t *mddev)
4602 {
4603 	mddev_t *mddev2;
4604 	unsigned int currspeed = 0,
4605 		 window;
4606 	sector_t max_sectors,j, io_sectors;
4607 	unsigned long mark[SYNC_MARKS];
4608 	sector_t mark_cnt[SYNC_MARKS];
4609 	int last_mark,m;
4610 	struct list_head *tmp;
4611 	sector_t last_check;
4612 	int skipped = 0;
4613 
4614 	/* just incase thread restarts... */
4615 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
4616 		return;
4617 
4618 	/* we overload curr_resync somewhat here.
4619 	 * 0 == not engaged in resync at all
4620 	 * 2 == checking that there is no conflict with another sync
4621 	 * 1 == like 2, but have yielded to allow conflicting resync to
4622 	 *		commense
4623 	 * other == active in resync - this many blocks
4624 	 *
4625 	 * Before starting a resync we must have set curr_resync to
4626 	 * 2, and then checked that every "conflicting" array has curr_resync
4627 	 * less than ours.  When we find one that is the same or higher
4628 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
4629 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
4630 	 * This will mean we have to start checking from the beginning again.
4631 	 *
4632 	 */
4633 
4634 	do {
4635 		mddev->curr_resync = 2;
4636 
4637 	try_again:
4638 		if (kthread_should_stop()) {
4639 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4640 			goto skip;
4641 		}
4642 		ITERATE_MDDEV(mddev2,tmp) {
4643 			if (mddev2 == mddev)
4644 				continue;
4645 			if (mddev2->curr_resync &&
4646 			    match_mddev_units(mddev,mddev2)) {
4647 				DEFINE_WAIT(wq);
4648 				if (mddev < mddev2 && mddev->curr_resync == 2) {
4649 					/* arbitrarily yield */
4650 					mddev->curr_resync = 1;
4651 					wake_up(&resync_wait);
4652 				}
4653 				if (mddev > mddev2 && mddev->curr_resync == 1)
4654 					/* no need to wait here, we can wait the next
4655 					 * time 'round when curr_resync == 2
4656 					 */
4657 					continue;
4658 				prepare_to_wait(&resync_wait, &wq, TASK_UNINTERRUPTIBLE);
4659 				if (!kthread_should_stop() &&
4660 				    mddev2->curr_resync >= mddev->curr_resync) {
4661 					printk(KERN_INFO "md: delaying resync of %s"
4662 					       " until %s has finished resync (they"
4663 					       " share one or more physical units)\n",
4664 					       mdname(mddev), mdname(mddev2));
4665 					mddev_put(mddev2);
4666 					schedule();
4667 					finish_wait(&resync_wait, &wq);
4668 					goto try_again;
4669 				}
4670 				finish_wait(&resync_wait, &wq);
4671 			}
4672 		}
4673 	} while (mddev->curr_resync < 2);
4674 
4675 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4676 		/* resync follows the size requested by the personality,
4677 		 * which defaults to physical size, but can be virtual size
4678 		 */
4679 		max_sectors = mddev->resync_max_sectors;
4680 		mddev->resync_mismatches = 0;
4681 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4682 		max_sectors = mddev->size << 1;
4683 	else
4684 		/* recovery follows the physical size of devices */
4685 		max_sectors = mddev->size << 1;
4686 
4687 	printk(KERN_INFO "md: syncing RAID array %s\n", mdname(mddev));
4688 	printk(KERN_INFO "md: minimum _guaranteed_ reconstruction speed:"
4689 		" %d KB/sec/disc.\n", speed_min(mddev));
4690 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
4691 	       "(but not more than %d KB/sec) for reconstruction.\n",
4692 	       speed_max(mddev));
4693 
4694 	is_mddev_idle(mddev); /* this also initializes IO event counters */
4695 	/* we don't use the checkpoint if there's a bitmap */
4696 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && !mddev->bitmap
4697 	    && ! test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4698 		j = mddev->recovery_cp;
4699 	else
4700 		j = 0;
4701 	io_sectors = 0;
4702 	for (m = 0; m < SYNC_MARKS; m++) {
4703 		mark[m] = jiffies;
4704 		mark_cnt[m] = io_sectors;
4705 	}
4706 	last_mark = 0;
4707 	mddev->resync_mark = mark[last_mark];
4708 	mddev->resync_mark_cnt = mark_cnt[last_mark];
4709 
4710 	/*
4711 	 * Tune reconstruction:
4712 	 */
4713 	window = 32*(PAGE_SIZE/512);
4714 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
4715 		window/2,(unsigned long long) max_sectors/2);
4716 
4717 	atomic_set(&mddev->recovery_active, 0);
4718 	init_waitqueue_head(&mddev->recovery_wait);
4719 	last_check = 0;
4720 
4721 	if (j>2) {
4722 		printk(KERN_INFO
4723 			"md: resuming recovery of %s from checkpoint.\n",
4724 			mdname(mddev));
4725 		mddev->curr_resync = j;
4726 	}
4727 
4728 	while (j < max_sectors) {
4729 		sector_t sectors;
4730 
4731 		skipped = 0;
4732 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
4733 					    currspeed < speed_min(mddev));
4734 		if (sectors == 0) {
4735 			set_bit(MD_RECOVERY_ERR, &mddev->recovery);
4736 			goto out;
4737 		}
4738 
4739 		if (!skipped) { /* actual IO requested */
4740 			io_sectors += sectors;
4741 			atomic_add(sectors, &mddev->recovery_active);
4742 		}
4743 
4744 		j += sectors;
4745 		if (j>1) mddev->curr_resync = j;
4746 		if (last_check == 0)
4747 			/* this is the earliers that rebuilt will be
4748 			 * visible in /proc/mdstat
4749 			 */
4750 			md_new_event(mddev);
4751 
4752 		if (last_check + window > io_sectors || j == max_sectors)
4753 			continue;
4754 
4755 		last_check = io_sectors;
4756 
4757 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
4758 		    test_bit(MD_RECOVERY_ERR, &mddev->recovery))
4759 			break;
4760 
4761 	repeat:
4762 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
4763 			/* step marks */
4764 			int next = (last_mark+1) % SYNC_MARKS;
4765 
4766 			mddev->resync_mark = mark[next];
4767 			mddev->resync_mark_cnt = mark_cnt[next];
4768 			mark[next] = jiffies;
4769 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
4770 			last_mark = next;
4771 		}
4772 
4773 
4774 		if (kthread_should_stop()) {
4775 			/*
4776 			 * got a signal, exit.
4777 			 */
4778 			printk(KERN_INFO
4779 				"md: md_do_sync() got signal ... exiting\n");
4780 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4781 			goto out;
4782 		}
4783 
4784 		/*
4785 		 * this loop exits only if either when we are slower than
4786 		 * the 'hard' speed limit, or the system was IO-idle for
4787 		 * a jiffy.
4788 		 * the system might be non-idle CPU-wise, but we only care
4789 		 * about not overloading the IO subsystem. (things like an
4790 		 * e2fsck being done on the RAID array should execute fast)
4791 		 */
4792 		mddev->queue->unplug_fn(mddev->queue);
4793 		cond_resched();
4794 
4795 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
4796 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
4797 
4798 		if (currspeed > speed_min(mddev)) {
4799 			if ((currspeed > speed_max(mddev)) ||
4800 					!is_mddev_idle(mddev)) {
4801 				msleep(500);
4802 				goto repeat;
4803 			}
4804 		}
4805 	}
4806 	printk(KERN_INFO "md: %s: sync done.\n",mdname(mddev));
4807 	/*
4808 	 * this also signals 'finished resyncing' to md_stop
4809 	 */
4810  out:
4811 	mddev->queue->unplug_fn(mddev->queue);
4812 
4813 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
4814 
4815 	/* tell personality that we are finished */
4816 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
4817 
4818 	if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
4819 	    test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
4820 	    !test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
4821 	    mddev->curr_resync > 2 &&
4822 	    mddev->curr_resync >= mddev->recovery_cp) {
4823 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4824 			printk(KERN_INFO
4825 				"md: checkpointing recovery of %s.\n",
4826 				mdname(mddev));
4827 			mddev->recovery_cp = mddev->curr_resync;
4828 		} else
4829 			mddev->recovery_cp = MaxSector;
4830 	}
4831 
4832  skip:
4833 	mddev->curr_resync = 0;
4834 	wake_up(&resync_wait);
4835 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
4836 	md_wakeup_thread(mddev->thread);
4837 }
4838 EXPORT_SYMBOL_GPL(md_do_sync);
4839 
4840 
4841 /*
4842  * This routine is regularly called by all per-raid-array threads to
4843  * deal with generic issues like resync and super-block update.
4844  * Raid personalities that don't have a thread (linear/raid0) do not
4845  * need this as they never do any recovery or update the superblock.
4846  *
4847  * It does not do any resync itself, but rather "forks" off other threads
4848  * to do that as needed.
4849  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
4850  * "->recovery" and create a thread at ->sync_thread.
4851  * When the thread finishes it sets MD_RECOVERY_DONE (and might set MD_RECOVERY_ERR)
4852  * and wakeups up this thread which will reap the thread and finish up.
4853  * This thread also removes any faulty devices (with nr_pending == 0).
4854  *
4855  * The overall approach is:
4856  *  1/ if the superblock needs updating, update it.
4857  *  2/ If a recovery thread is running, don't do anything else.
4858  *  3/ If recovery has finished, clean up, possibly marking spares active.
4859  *  4/ If there are any faulty devices, remove them.
4860  *  5/ If array is degraded, try to add spares devices
4861  *  6/ If array has spares or is not in-sync, start a resync thread.
4862  */
4863 void md_check_recovery(mddev_t *mddev)
4864 {
4865 	mdk_rdev_t *rdev;
4866 	struct list_head *rtmp;
4867 
4868 
4869 	if (mddev->bitmap)
4870 		bitmap_daemon_work(mddev->bitmap);
4871 
4872 	if (mddev->ro)
4873 		return;
4874 
4875 	if (signal_pending(current)) {
4876 		if (mddev->pers->sync_request) {
4877 			printk(KERN_INFO "md: %s in immediate safe mode\n",
4878 			       mdname(mddev));
4879 			mddev->safemode = 2;
4880 		}
4881 		flush_signals(current);
4882 	}
4883 
4884 	if ( ! (
4885 		mddev->sb_dirty ||
4886 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
4887 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
4888 		(mddev->safemode == 1) ||
4889 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
4890 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
4891 		))
4892 		return;
4893 
4894 	if (mddev_trylock(mddev)) {
4895 		int spares =0;
4896 
4897 		spin_lock_irq(&mddev->write_lock);
4898 		if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
4899 		    !mddev->in_sync && mddev->recovery_cp == MaxSector) {
4900 			mddev->in_sync = 1;
4901 			mddev->sb_dirty = 1;
4902 		}
4903 		if (mddev->safemode == 1)
4904 			mddev->safemode = 0;
4905 		spin_unlock_irq(&mddev->write_lock);
4906 
4907 		if (mddev->sb_dirty)
4908 			md_update_sb(mddev);
4909 
4910 
4911 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
4912 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
4913 			/* resync/recovery still happening */
4914 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4915 			goto unlock;
4916 		}
4917 		if (mddev->sync_thread) {
4918 			/* resync has finished, collect result */
4919 			md_unregister_thread(mddev->sync_thread);
4920 			mddev->sync_thread = NULL;
4921 			if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
4922 			    !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4923 				/* success...*/
4924 				/* activate any spares */
4925 				mddev->pers->spare_active(mddev);
4926 			}
4927 			md_update_sb(mddev);
4928 
4929 			/* if array is no-longer degraded, then any saved_raid_disk
4930 			 * information must be scrapped
4931 			 */
4932 			if (!mddev->degraded)
4933 				ITERATE_RDEV(mddev,rdev,rtmp)
4934 					rdev->saved_raid_disk = -1;
4935 
4936 			mddev->recovery = 0;
4937 			/* flag recovery needed just to double check */
4938 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4939 			md_new_event(mddev);
4940 			goto unlock;
4941 		}
4942 		/* Clear some bits that don't mean anything, but
4943 		 * might be left set
4944 		 */
4945 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4946 		clear_bit(MD_RECOVERY_ERR, &mddev->recovery);
4947 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
4948 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
4949 
4950 		/* no recovery is running.
4951 		 * remove any failed drives, then
4952 		 * add spares if possible.
4953 		 * Spare are also removed and re-added, to allow
4954 		 * the personality to fail the re-add.
4955 		 */
4956 		ITERATE_RDEV(mddev,rdev,rtmp)
4957 			if (rdev->raid_disk >= 0 &&
4958 			    (test_bit(Faulty, &rdev->flags) || ! test_bit(In_sync, &rdev->flags)) &&
4959 			    atomic_read(&rdev->nr_pending)==0) {
4960 				if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0) {
4961 					char nm[20];
4962 					sprintf(nm,"rd%d", rdev->raid_disk);
4963 					sysfs_remove_link(&mddev->kobj, nm);
4964 					rdev->raid_disk = -1;
4965 				}
4966 			}
4967 
4968 		if (mddev->degraded) {
4969 			ITERATE_RDEV(mddev,rdev,rtmp)
4970 				if (rdev->raid_disk < 0
4971 				    && !test_bit(Faulty, &rdev->flags)) {
4972 					if (mddev->pers->hot_add_disk(mddev,rdev)) {
4973 						char nm[20];
4974 						sprintf(nm, "rd%d", rdev->raid_disk);
4975 						sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
4976 						spares++;
4977 						md_new_event(mddev);
4978 					} else
4979 						break;
4980 				}
4981 		}
4982 
4983 		if (spares) {
4984 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4985 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4986 		} else if (mddev->recovery_cp < MaxSector) {
4987 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4988 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4989 			/* nothing to be done ... */
4990 			goto unlock;
4991 
4992 		if (mddev->pers->sync_request) {
4993 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4994 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
4995 				/* We are adding a device or devices to an array
4996 				 * which has the bitmap stored on all devices.
4997 				 * So make sure all bitmap pages get written
4998 				 */
4999 				bitmap_write_all(mddev->bitmap);
5000 			}
5001 			mddev->sync_thread = md_register_thread(md_do_sync,
5002 								mddev,
5003 								"%s_resync");
5004 			if (!mddev->sync_thread) {
5005 				printk(KERN_ERR "%s: could not start resync"
5006 					" thread...\n",
5007 					mdname(mddev));
5008 				/* leave the spares where they are, it shouldn't hurt */
5009 				mddev->recovery = 0;
5010 			} else
5011 				md_wakeup_thread(mddev->sync_thread);
5012 			md_new_event(mddev);
5013 		}
5014 	unlock:
5015 		mddev_unlock(mddev);
5016 	}
5017 }
5018 
5019 static int md_notify_reboot(struct notifier_block *this,
5020 			    unsigned long code, void *x)
5021 {
5022 	struct list_head *tmp;
5023 	mddev_t *mddev;
5024 
5025 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
5026 
5027 		printk(KERN_INFO "md: stopping all md devices.\n");
5028 
5029 		ITERATE_MDDEV(mddev,tmp)
5030 			if (mddev_trylock(mddev))
5031 				do_md_stop (mddev, 1);
5032 		/*
5033 		 * certain more exotic SCSI devices are known to be
5034 		 * volatile wrt too early system reboots. While the
5035 		 * right place to handle this issue is the given
5036 		 * driver, we do want to have a safe RAID driver ...
5037 		 */
5038 		mdelay(1000*1);
5039 	}
5040 	return NOTIFY_DONE;
5041 }
5042 
5043 static struct notifier_block md_notifier = {
5044 	.notifier_call	= md_notify_reboot,
5045 	.next		= NULL,
5046 	.priority	= INT_MAX, /* before any real devices */
5047 };
5048 
5049 static void md_geninit(void)
5050 {
5051 	struct proc_dir_entry *p;
5052 
5053 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
5054 
5055 	p = create_proc_entry("mdstat", S_IRUGO, NULL);
5056 	if (p)
5057 		p->proc_fops = &md_seq_fops;
5058 }
5059 
5060 static int __init md_init(void)
5061 {
5062 	int minor;
5063 
5064 	printk(KERN_INFO "md: md driver %d.%d.%d MAX_MD_DEVS=%d,"
5065 			" MD_SB_DISKS=%d\n",
5066 			MD_MAJOR_VERSION, MD_MINOR_VERSION,
5067 			MD_PATCHLEVEL_VERSION, MAX_MD_DEVS, MD_SB_DISKS);
5068 	printk(KERN_INFO "md: bitmap version %d.%d\n", BITMAP_MAJOR_HI,
5069 			BITMAP_MINOR);
5070 
5071 	if (register_blkdev(MAJOR_NR, "md"))
5072 		return -1;
5073 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
5074 		unregister_blkdev(MAJOR_NR, "md");
5075 		return -1;
5076 	}
5077 	devfs_mk_dir("md");
5078 	blk_register_region(MKDEV(MAJOR_NR, 0), MAX_MD_DEVS, THIS_MODULE,
5079 				md_probe, NULL, NULL);
5080 	blk_register_region(MKDEV(mdp_major, 0), MAX_MD_DEVS<<MdpMinorShift, THIS_MODULE,
5081 			    md_probe, NULL, NULL);
5082 
5083 	for (minor=0; minor < MAX_MD_DEVS; ++minor)
5084 		devfs_mk_bdev(MKDEV(MAJOR_NR, minor),
5085 				S_IFBLK|S_IRUSR|S_IWUSR,
5086 				"md/%d", minor);
5087 
5088 	for (minor=0; minor < MAX_MD_DEVS; ++minor)
5089 		devfs_mk_bdev(MKDEV(mdp_major, minor<<MdpMinorShift),
5090 			      S_IFBLK|S_IRUSR|S_IWUSR,
5091 			      "md/mdp%d", minor);
5092 
5093 
5094 	register_reboot_notifier(&md_notifier);
5095 	raid_table_header = register_sysctl_table(raid_root_table, 1);
5096 
5097 	md_geninit();
5098 	return (0);
5099 }
5100 
5101 
5102 #ifndef MODULE
5103 
5104 /*
5105  * Searches all registered partitions for autorun RAID arrays
5106  * at boot time.
5107  */
5108 static dev_t detected_devices[128];
5109 static int dev_cnt;
5110 
5111 void md_autodetect_dev(dev_t dev)
5112 {
5113 	if (dev_cnt >= 0 && dev_cnt < 127)
5114 		detected_devices[dev_cnt++] = dev;
5115 }
5116 
5117 
5118 static void autostart_arrays(int part)
5119 {
5120 	mdk_rdev_t *rdev;
5121 	int i;
5122 
5123 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
5124 
5125 	for (i = 0; i < dev_cnt; i++) {
5126 		dev_t dev = detected_devices[i];
5127 
5128 		rdev = md_import_device(dev,0, 0);
5129 		if (IS_ERR(rdev))
5130 			continue;
5131 
5132 		if (test_bit(Faulty, &rdev->flags)) {
5133 			MD_BUG();
5134 			continue;
5135 		}
5136 		list_add(&rdev->same_set, &pending_raid_disks);
5137 	}
5138 	dev_cnt = 0;
5139 
5140 	autorun_devices(part);
5141 }
5142 
5143 #endif
5144 
5145 static __exit void md_exit(void)
5146 {
5147 	mddev_t *mddev;
5148 	struct list_head *tmp;
5149 	int i;
5150 	blk_unregister_region(MKDEV(MAJOR_NR,0), MAX_MD_DEVS);
5151 	blk_unregister_region(MKDEV(mdp_major,0), MAX_MD_DEVS << MdpMinorShift);
5152 	for (i=0; i < MAX_MD_DEVS; i++)
5153 		devfs_remove("md/%d", i);
5154 	for (i=0; i < MAX_MD_DEVS; i++)
5155 		devfs_remove("md/d%d", i);
5156 
5157 	devfs_remove("md");
5158 
5159 	unregister_blkdev(MAJOR_NR,"md");
5160 	unregister_blkdev(mdp_major, "mdp");
5161 	unregister_reboot_notifier(&md_notifier);
5162 	unregister_sysctl_table(raid_table_header);
5163 	remove_proc_entry("mdstat", NULL);
5164 	ITERATE_MDDEV(mddev,tmp) {
5165 		struct gendisk *disk = mddev->gendisk;
5166 		if (!disk)
5167 			continue;
5168 		export_array(mddev);
5169 		del_gendisk(disk);
5170 		put_disk(disk);
5171 		mddev->gendisk = NULL;
5172 		mddev_put(mddev);
5173 	}
5174 }
5175 
5176 module_init(md_init)
5177 module_exit(md_exit)
5178 
5179 static int get_ro(char *buffer, struct kernel_param *kp)
5180 {
5181 	return sprintf(buffer, "%d", start_readonly);
5182 }
5183 static int set_ro(const char *val, struct kernel_param *kp)
5184 {
5185 	char *e;
5186 	int num = simple_strtoul(val, &e, 10);
5187 	if (*val && (*e == '\0' || *e == '\n')) {
5188 		start_readonly = num;
5189 		return 0;
5190 	}
5191 	return -EINVAL;
5192 }
5193 
5194 module_param_call(start_ro, set_ro, get_ro, NULL, 0600);
5195 module_param(start_dirty_degraded, int, 0644);
5196 
5197 
5198 EXPORT_SYMBOL(register_md_personality);
5199 EXPORT_SYMBOL(unregister_md_personality);
5200 EXPORT_SYMBOL(md_error);
5201 EXPORT_SYMBOL(md_done_sync);
5202 EXPORT_SYMBOL(md_write_start);
5203 EXPORT_SYMBOL(md_write_end);
5204 EXPORT_SYMBOL(md_register_thread);
5205 EXPORT_SYMBOL(md_unregister_thread);
5206 EXPORT_SYMBOL(md_wakeup_thread);
5207 EXPORT_SYMBOL(md_print_devices);
5208 EXPORT_SYMBOL(md_check_recovery);
5209 MODULE_LICENSE("GPL");
5210 MODULE_ALIAS("md");
5211 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
5212