xref: /linux/drivers/md/md.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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 		/* that blocks */
219 		blk_cleanup_queue(mddev->queue);
220 		/* that also blocks */
221 		kobject_unregister(&mddev->kobj);
222 		/* result blows... */
223 	}
224 	spin_unlock(&all_mddevs_lock);
225 }
226 
227 static mddev_t * mddev_find(dev_t unit)
228 {
229 	mddev_t *mddev, *new = NULL;
230 
231  retry:
232 	spin_lock(&all_mddevs_lock);
233 	list_for_each_entry(mddev, &all_mddevs, all_mddevs)
234 		if (mddev->unit == unit) {
235 			mddev_get(mddev);
236 			spin_unlock(&all_mddevs_lock);
237 			kfree(new);
238 			return mddev;
239 		}
240 
241 	if (new) {
242 		list_add(&new->all_mddevs, &all_mddevs);
243 		spin_unlock(&all_mddevs_lock);
244 		return new;
245 	}
246 	spin_unlock(&all_mddevs_lock);
247 
248 	new = kzalloc(sizeof(*new), GFP_KERNEL);
249 	if (!new)
250 		return NULL;
251 
252 	new->unit = unit;
253 	if (MAJOR(unit) == MD_MAJOR)
254 		new->md_minor = MINOR(unit);
255 	else
256 		new->md_minor = MINOR(unit) >> MdpMinorShift;
257 
258 	mutex_init(&new->reconfig_mutex);
259 	INIT_LIST_HEAD(&new->disks);
260 	INIT_LIST_HEAD(&new->all_mddevs);
261 	init_timer(&new->safemode_timer);
262 	atomic_set(&new->active, 1);
263 	spin_lock_init(&new->write_lock);
264 	init_waitqueue_head(&new->sb_wait);
265 
266 	new->queue = blk_alloc_queue(GFP_KERNEL);
267 	if (!new->queue) {
268 		kfree(new);
269 		return NULL;
270 	}
271 	set_bit(QUEUE_FLAG_CLUSTER, &new->queue->queue_flags);
272 
273 	blk_queue_make_request(new->queue, md_fail_request);
274 
275 	goto retry;
276 }
277 
278 static inline int mddev_lock(mddev_t * mddev)
279 {
280 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
281 }
282 
283 static inline void mddev_lock_uninterruptible(mddev_t * mddev)
284 {
285 	mutex_lock(&mddev->reconfig_mutex);
286 }
287 
288 static inline int mddev_trylock(mddev_t * mddev)
289 {
290 	return mutex_trylock(&mddev->reconfig_mutex);
291 }
292 
293 static inline void mddev_unlock(mddev_t * mddev)
294 {
295 	mutex_unlock(&mddev->reconfig_mutex);
296 
297 	md_wakeup_thread(mddev->thread);
298 }
299 
300 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
301 {
302 	mdk_rdev_t * rdev;
303 	struct list_head *tmp;
304 
305 	ITERATE_RDEV(mddev,rdev,tmp) {
306 		if (rdev->desc_nr == nr)
307 			return rdev;
308 	}
309 	return NULL;
310 }
311 
312 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
313 {
314 	struct list_head *tmp;
315 	mdk_rdev_t *rdev;
316 
317 	ITERATE_RDEV(mddev,rdev,tmp) {
318 		if (rdev->bdev->bd_dev == dev)
319 			return rdev;
320 	}
321 	return NULL;
322 }
323 
324 static struct mdk_personality *find_pers(int level, char *clevel)
325 {
326 	struct mdk_personality *pers;
327 	list_for_each_entry(pers, &pers_list, list) {
328 		if (level != LEVEL_NONE && pers->level == level)
329 			return pers;
330 		if (strcmp(pers->name, clevel)==0)
331 			return pers;
332 	}
333 	return NULL;
334 }
335 
336 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
337 {
338 	sector_t size = bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
339 	return MD_NEW_SIZE_BLOCKS(size);
340 }
341 
342 static sector_t calc_dev_size(mdk_rdev_t *rdev, unsigned chunk_size)
343 {
344 	sector_t size;
345 
346 	size = rdev->sb_offset;
347 
348 	if (chunk_size)
349 		size &= ~((sector_t)chunk_size/1024 - 1);
350 	return size;
351 }
352 
353 static int alloc_disk_sb(mdk_rdev_t * rdev)
354 {
355 	if (rdev->sb_page)
356 		MD_BUG();
357 
358 	rdev->sb_page = alloc_page(GFP_KERNEL);
359 	if (!rdev->sb_page) {
360 		printk(KERN_ALERT "md: out of memory.\n");
361 		return -EINVAL;
362 	}
363 
364 	return 0;
365 }
366 
367 static void free_disk_sb(mdk_rdev_t * rdev)
368 {
369 	if (rdev->sb_page) {
370 		put_page(rdev->sb_page);
371 		rdev->sb_loaded = 0;
372 		rdev->sb_page = NULL;
373 		rdev->sb_offset = 0;
374 		rdev->size = 0;
375 	}
376 }
377 
378 
379 static int super_written(struct bio *bio, unsigned int bytes_done, int error)
380 {
381 	mdk_rdev_t *rdev = bio->bi_private;
382 	mddev_t *mddev = rdev->mddev;
383 	if (bio->bi_size)
384 		return 1;
385 
386 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags))
387 		md_error(mddev, rdev);
388 
389 	if (atomic_dec_and_test(&mddev->pending_writes))
390 		wake_up(&mddev->sb_wait);
391 	bio_put(bio);
392 	return 0;
393 }
394 
395 static int super_written_barrier(struct bio *bio, unsigned int bytes_done, int error)
396 {
397 	struct bio *bio2 = bio->bi_private;
398 	mdk_rdev_t *rdev = bio2->bi_private;
399 	mddev_t *mddev = rdev->mddev;
400 	if (bio->bi_size)
401 		return 1;
402 
403 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
404 	    error == -EOPNOTSUPP) {
405 		unsigned long flags;
406 		/* barriers don't appear to be supported :-( */
407 		set_bit(BarriersNotsupp, &rdev->flags);
408 		mddev->barriers_work = 0;
409 		spin_lock_irqsave(&mddev->write_lock, flags);
410 		bio2->bi_next = mddev->biolist;
411 		mddev->biolist = bio2;
412 		spin_unlock_irqrestore(&mddev->write_lock, flags);
413 		wake_up(&mddev->sb_wait);
414 		bio_put(bio);
415 		return 0;
416 	}
417 	bio_put(bio2);
418 	bio->bi_private = rdev;
419 	return super_written(bio, bytes_done, error);
420 }
421 
422 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
423 		   sector_t sector, int size, struct page *page)
424 {
425 	/* write first size bytes of page to sector of rdev
426 	 * Increment mddev->pending_writes before returning
427 	 * and decrement it on completion, waking up sb_wait
428 	 * if zero is reached.
429 	 * If an error occurred, call md_error
430 	 *
431 	 * As we might need to resubmit the request if BIO_RW_BARRIER
432 	 * causes ENOTSUPP, we allocate a spare bio...
433 	 */
434 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
435 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNC);
436 
437 	bio->bi_bdev = rdev->bdev;
438 	bio->bi_sector = sector;
439 	bio_add_page(bio, page, size, 0);
440 	bio->bi_private = rdev;
441 	bio->bi_end_io = super_written;
442 	bio->bi_rw = rw;
443 
444 	atomic_inc(&mddev->pending_writes);
445 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
446 		struct bio *rbio;
447 		rw |= (1<<BIO_RW_BARRIER);
448 		rbio = bio_clone(bio, GFP_NOIO);
449 		rbio->bi_private = bio;
450 		rbio->bi_end_io = super_written_barrier;
451 		submit_bio(rw, rbio);
452 	} else
453 		submit_bio(rw, bio);
454 }
455 
456 void md_super_wait(mddev_t *mddev)
457 {
458 	/* wait for all superblock writes that were scheduled to complete.
459 	 * if any had to be retried (due to BARRIER problems), retry them
460 	 */
461 	DEFINE_WAIT(wq);
462 	for(;;) {
463 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
464 		if (atomic_read(&mddev->pending_writes)==0)
465 			break;
466 		while (mddev->biolist) {
467 			struct bio *bio;
468 			spin_lock_irq(&mddev->write_lock);
469 			bio = mddev->biolist;
470 			mddev->biolist = bio->bi_next ;
471 			bio->bi_next = NULL;
472 			spin_unlock_irq(&mddev->write_lock);
473 			submit_bio(bio->bi_rw, bio);
474 		}
475 		schedule();
476 	}
477 	finish_wait(&mddev->sb_wait, &wq);
478 }
479 
480 static int bi_complete(struct bio *bio, unsigned int bytes_done, int error)
481 {
482 	if (bio->bi_size)
483 		return 1;
484 
485 	complete((struct completion*)bio->bi_private);
486 	return 0;
487 }
488 
489 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
490 		   struct page *page, int rw)
491 {
492 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
493 	struct completion event;
494 	int ret;
495 
496 	rw |= (1 << BIO_RW_SYNC);
497 
498 	bio->bi_bdev = bdev;
499 	bio->bi_sector = sector;
500 	bio_add_page(bio, page, size, 0);
501 	init_completion(&event);
502 	bio->bi_private = &event;
503 	bio->bi_end_io = bi_complete;
504 	submit_bio(rw, bio);
505 	wait_for_completion(&event);
506 
507 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
508 	bio_put(bio);
509 	return ret;
510 }
511 EXPORT_SYMBOL_GPL(sync_page_io);
512 
513 static int read_disk_sb(mdk_rdev_t * rdev, int size)
514 {
515 	char b[BDEVNAME_SIZE];
516 	if (!rdev->sb_page) {
517 		MD_BUG();
518 		return -EINVAL;
519 	}
520 	if (rdev->sb_loaded)
521 		return 0;
522 
523 
524 	if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, size, rdev->sb_page, READ))
525 		goto fail;
526 	rdev->sb_loaded = 1;
527 	return 0;
528 
529 fail:
530 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
531 		bdevname(rdev->bdev,b));
532 	return -EINVAL;
533 }
534 
535 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
536 {
537 	if (	(sb1->set_uuid0 == sb2->set_uuid0) &&
538 		(sb1->set_uuid1 == sb2->set_uuid1) &&
539 		(sb1->set_uuid2 == sb2->set_uuid2) &&
540 		(sb1->set_uuid3 == sb2->set_uuid3))
541 
542 		return 1;
543 
544 	return 0;
545 }
546 
547 
548 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
549 {
550 	int ret;
551 	mdp_super_t *tmp1, *tmp2;
552 
553 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
554 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
555 
556 	if (!tmp1 || !tmp2) {
557 		ret = 0;
558 		printk(KERN_INFO "md.c: sb1 is not equal to sb2!\n");
559 		goto abort;
560 	}
561 
562 	*tmp1 = *sb1;
563 	*tmp2 = *sb2;
564 
565 	/*
566 	 * nr_disks is not constant
567 	 */
568 	tmp1->nr_disks = 0;
569 	tmp2->nr_disks = 0;
570 
571 	if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
572 		ret = 0;
573 	else
574 		ret = 1;
575 
576 abort:
577 	kfree(tmp1);
578 	kfree(tmp2);
579 	return ret;
580 }
581 
582 static unsigned int calc_sb_csum(mdp_super_t * sb)
583 {
584 	unsigned int disk_csum, csum;
585 
586 	disk_csum = sb->sb_csum;
587 	sb->sb_csum = 0;
588 	csum = csum_partial((void *)sb, MD_SB_BYTES, 0);
589 	sb->sb_csum = disk_csum;
590 	return csum;
591 }
592 
593 
594 /*
595  * Handle superblock details.
596  * We want to be able to handle multiple superblock formats
597  * so we have a common interface to them all, and an array of
598  * different handlers.
599  * We rely on user-space to write the initial superblock, and support
600  * reading and updating of superblocks.
601  * Interface methods are:
602  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
603  *      loads and validates a superblock on dev.
604  *      if refdev != NULL, compare superblocks on both devices
605  *    Return:
606  *      0 - dev has a superblock that is compatible with refdev
607  *      1 - dev has a superblock that is compatible and newer than refdev
608  *          so dev should be used as the refdev in future
609  *     -EINVAL superblock incompatible or invalid
610  *     -othererror e.g. -EIO
611  *
612  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
613  *      Verify that dev is acceptable into mddev.
614  *       The first time, mddev->raid_disks will be 0, and data from
615  *       dev should be merged in.  Subsequent calls check that dev
616  *       is new enough.  Return 0 or -EINVAL
617  *
618  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
619  *     Update the superblock for rdev with data in mddev
620  *     This does not write to disc.
621  *
622  */
623 
624 struct super_type  {
625 	char 		*name;
626 	struct module	*owner;
627 	int		(*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version);
628 	int		(*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
629 	void		(*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
630 };
631 
632 /*
633  * load_super for 0.90.0
634  */
635 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
636 {
637 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
638 	mdp_super_t *sb;
639 	int ret;
640 	sector_t sb_offset;
641 
642 	/*
643 	 * Calculate the position of the superblock,
644 	 * it's at the end of the disk.
645 	 *
646 	 * It also happens to be a multiple of 4Kb.
647 	 */
648 	sb_offset = calc_dev_sboffset(rdev->bdev);
649 	rdev->sb_offset = sb_offset;
650 
651 	ret = read_disk_sb(rdev, MD_SB_BYTES);
652 	if (ret) return ret;
653 
654 	ret = -EINVAL;
655 
656 	bdevname(rdev->bdev, b);
657 	sb = (mdp_super_t*)page_address(rdev->sb_page);
658 
659 	if (sb->md_magic != MD_SB_MAGIC) {
660 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
661 		       b);
662 		goto abort;
663 	}
664 
665 	if (sb->major_version != 0 ||
666 	    sb->minor_version < 90 ||
667 	    sb->minor_version > 91) {
668 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
669 			sb->major_version, sb->minor_version,
670 			b);
671 		goto abort;
672 	}
673 
674 	if (sb->raid_disks <= 0)
675 		goto abort;
676 
677 	if (csum_fold(calc_sb_csum(sb)) != csum_fold(sb->sb_csum)) {
678 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
679 			b);
680 		goto abort;
681 	}
682 
683 	rdev->preferred_minor = sb->md_minor;
684 	rdev->data_offset = 0;
685 	rdev->sb_size = MD_SB_BYTES;
686 
687 	if (sb->level == LEVEL_MULTIPATH)
688 		rdev->desc_nr = -1;
689 	else
690 		rdev->desc_nr = sb->this_disk.number;
691 
692 	if (refdev == 0)
693 		ret = 1;
694 	else {
695 		__u64 ev1, ev2;
696 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
697 		if (!uuid_equal(refsb, sb)) {
698 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
699 				b, bdevname(refdev->bdev,b2));
700 			goto abort;
701 		}
702 		if (!sb_equal(refsb, sb)) {
703 			printk(KERN_WARNING "md: %s has same UUID"
704 			       " but different superblock to %s\n",
705 			       b, bdevname(refdev->bdev, b2));
706 			goto abort;
707 		}
708 		ev1 = md_event(sb);
709 		ev2 = md_event(refsb);
710 		if (ev1 > ev2)
711 			ret = 1;
712 		else
713 			ret = 0;
714 	}
715 	rdev->size = calc_dev_size(rdev, sb->chunk_size);
716 
717 	if (rdev->size < sb->size && sb->level > 1)
718 		/* "this cannot possibly happen" ... */
719 		ret = -EINVAL;
720 
721  abort:
722 	return ret;
723 }
724 
725 /*
726  * validate_super for 0.90.0
727  */
728 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
729 {
730 	mdp_disk_t *desc;
731 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
732 
733 	rdev->raid_disk = -1;
734 	rdev->flags = 0;
735 	if (mddev->raid_disks == 0) {
736 		mddev->major_version = 0;
737 		mddev->minor_version = sb->minor_version;
738 		mddev->patch_version = sb->patch_version;
739 		mddev->persistent = ! sb->not_persistent;
740 		mddev->chunk_size = sb->chunk_size;
741 		mddev->ctime = sb->ctime;
742 		mddev->utime = sb->utime;
743 		mddev->level = sb->level;
744 		mddev->clevel[0] = 0;
745 		mddev->layout = sb->layout;
746 		mddev->raid_disks = sb->raid_disks;
747 		mddev->size = sb->size;
748 		mddev->events = md_event(sb);
749 		mddev->bitmap_offset = 0;
750 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
751 
752 		if (mddev->minor_version >= 91) {
753 			mddev->reshape_position = sb->reshape_position;
754 			mddev->delta_disks = sb->delta_disks;
755 			mddev->new_level = sb->new_level;
756 			mddev->new_layout = sb->new_layout;
757 			mddev->new_chunk = sb->new_chunk;
758 		} else {
759 			mddev->reshape_position = MaxSector;
760 			mddev->delta_disks = 0;
761 			mddev->new_level = mddev->level;
762 			mddev->new_layout = mddev->layout;
763 			mddev->new_chunk = mddev->chunk_size;
764 		}
765 
766 		if (sb->state & (1<<MD_SB_CLEAN))
767 			mddev->recovery_cp = MaxSector;
768 		else {
769 			if (sb->events_hi == sb->cp_events_hi &&
770 				sb->events_lo == sb->cp_events_lo) {
771 				mddev->recovery_cp = sb->recovery_cp;
772 			} else
773 				mddev->recovery_cp = 0;
774 		}
775 
776 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
777 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
778 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
779 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
780 
781 		mddev->max_disks = MD_SB_DISKS;
782 
783 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
784 		    mddev->bitmap_file == NULL) {
785 			if (mddev->level != 1 && mddev->level != 4
786 			    && mddev->level != 5 && mddev->level != 6
787 			    && mddev->level != 10) {
788 				/* FIXME use a better test */
789 				printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
790 				return -EINVAL;
791 			}
792 			mddev->bitmap_offset = mddev->default_bitmap_offset;
793 		}
794 
795 	} else if (mddev->pers == NULL) {
796 		/* Insist on good event counter while assembling */
797 		__u64 ev1 = md_event(sb);
798 		++ev1;
799 		if (ev1 < mddev->events)
800 			return -EINVAL;
801 	} else if (mddev->bitmap) {
802 		/* if adding to array with a bitmap, then we can accept an
803 		 * older device ... but not too old.
804 		 */
805 		__u64 ev1 = md_event(sb);
806 		if (ev1 < mddev->bitmap->events_cleared)
807 			return 0;
808 	} else /* just a hot-add of a new device, leave raid_disk at -1 */
809 		return 0;
810 
811 	if (mddev->level != LEVEL_MULTIPATH) {
812 		desc = sb->disks + rdev->desc_nr;
813 
814 		if (desc->state & (1<<MD_DISK_FAULTY))
815 			set_bit(Faulty, &rdev->flags);
816 		else if (desc->state & (1<<MD_DISK_SYNC) &&
817 			 desc->raid_disk < mddev->raid_disks) {
818 			set_bit(In_sync, &rdev->flags);
819 			rdev->raid_disk = desc->raid_disk;
820 		}
821 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
822 			set_bit(WriteMostly, &rdev->flags);
823 	} else /* MULTIPATH are always insync */
824 		set_bit(In_sync, &rdev->flags);
825 	return 0;
826 }
827 
828 /*
829  * sync_super for 0.90.0
830  */
831 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
832 {
833 	mdp_super_t *sb;
834 	struct list_head *tmp;
835 	mdk_rdev_t *rdev2;
836 	int next_spare = mddev->raid_disks;
837 
838 
839 	/* make rdev->sb match mddev data..
840 	 *
841 	 * 1/ zero out disks
842 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
843 	 * 3/ any empty disks < next_spare become removed
844 	 *
845 	 * disks[0] gets initialised to REMOVED because
846 	 * we cannot be sure from other fields if it has
847 	 * been initialised or not.
848 	 */
849 	int i;
850 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
851 
852 	rdev->sb_size = MD_SB_BYTES;
853 
854 	sb = (mdp_super_t*)page_address(rdev->sb_page);
855 
856 	memset(sb, 0, sizeof(*sb));
857 
858 	sb->md_magic = MD_SB_MAGIC;
859 	sb->major_version = mddev->major_version;
860 	sb->patch_version = mddev->patch_version;
861 	sb->gvalid_words  = 0; /* ignored */
862 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
863 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
864 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
865 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
866 
867 	sb->ctime = mddev->ctime;
868 	sb->level = mddev->level;
869 	sb->size  = mddev->size;
870 	sb->raid_disks = mddev->raid_disks;
871 	sb->md_minor = mddev->md_minor;
872 	sb->not_persistent = !mddev->persistent;
873 	sb->utime = mddev->utime;
874 	sb->state = 0;
875 	sb->events_hi = (mddev->events>>32);
876 	sb->events_lo = (u32)mddev->events;
877 
878 	if (mddev->reshape_position == MaxSector)
879 		sb->minor_version = 90;
880 	else {
881 		sb->minor_version = 91;
882 		sb->reshape_position = mddev->reshape_position;
883 		sb->new_level = mddev->new_level;
884 		sb->delta_disks = mddev->delta_disks;
885 		sb->new_layout = mddev->new_layout;
886 		sb->new_chunk = mddev->new_chunk;
887 	}
888 	mddev->minor_version = sb->minor_version;
889 	if (mddev->in_sync)
890 	{
891 		sb->recovery_cp = mddev->recovery_cp;
892 		sb->cp_events_hi = (mddev->events>>32);
893 		sb->cp_events_lo = (u32)mddev->events;
894 		if (mddev->recovery_cp == MaxSector)
895 			sb->state = (1<< MD_SB_CLEAN);
896 	} else
897 		sb->recovery_cp = 0;
898 
899 	sb->layout = mddev->layout;
900 	sb->chunk_size = mddev->chunk_size;
901 
902 	if (mddev->bitmap && mddev->bitmap_file == NULL)
903 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
904 
905 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
906 	ITERATE_RDEV(mddev,rdev2,tmp) {
907 		mdp_disk_t *d;
908 		int desc_nr;
909 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
910 		    && !test_bit(Faulty, &rdev2->flags))
911 			desc_nr = rdev2->raid_disk;
912 		else
913 			desc_nr = next_spare++;
914 		rdev2->desc_nr = desc_nr;
915 		d = &sb->disks[rdev2->desc_nr];
916 		nr_disks++;
917 		d->number = rdev2->desc_nr;
918 		d->major = MAJOR(rdev2->bdev->bd_dev);
919 		d->minor = MINOR(rdev2->bdev->bd_dev);
920 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
921 		    && !test_bit(Faulty, &rdev2->flags))
922 			d->raid_disk = rdev2->raid_disk;
923 		else
924 			d->raid_disk = rdev2->desc_nr; /* compatibility */
925 		if (test_bit(Faulty, &rdev2->flags))
926 			d->state = (1<<MD_DISK_FAULTY);
927 		else if (test_bit(In_sync, &rdev2->flags)) {
928 			d->state = (1<<MD_DISK_ACTIVE);
929 			d->state |= (1<<MD_DISK_SYNC);
930 			active++;
931 			working++;
932 		} else {
933 			d->state = 0;
934 			spare++;
935 			working++;
936 		}
937 		if (test_bit(WriteMostly, &rdev2->flags))
938 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
939 	}
940 	/* now set the "removed" and "faulty" bits on any missing devices */
941 	for (i=0 ; i < mddev->raid_disks ; i++) {
942 		mdp_disk_t *d = &sb->disks[i];
943 		if (d->state == 0 && d->number == 0) {
944 			d->number = i;
945 			d->raid_disk = i;
946 			d->state = (1<<MD_DISK_REMOVED);
947 			d->state |= (1<<MD_DISK_FAULTY);
948 			failed++;
949 		}
950 	}
951 	sb->nr_disks = nr_disks;
952 	sb->active_disks = active;
953 	sb->working_disks = working;
954 	sb->failed_disks = failed;
955 	sb->spare_disks = spare;
956 
957 	sb->this_disk = sb->disks[rdev->desc_nr];
958 	sb->sb_csum = calc_sb_csum(sb);
959 }
960 
961 /*
962  * version 1 superblock
963  */
964 
965 static unsigned int calc_sb_1_csum(struct mdp_superblock_1 * sb)
966 {
967 	unsigned int disk_csum, csum;
968 	unsigned long long newcsum;
969 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
970 	unsigned int *isuper = (unsigned int*)sb;
971 	int i;
972 
973 	disk_csum = sb->sb_csum;
974 	sb->sb_csum = 0;
975 	newcsum = 0;
976 	for (i=0; size>=4; size -= 4 )
977 		newcsum += le32_to_cpu(*isuper++);
978 
979 	if (size == 2)
980 		newcsum += le16_to_cpu(*(unsigned short*) isuper);
981 
982 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
983 	sb->sb_csum = disk_csum;
984 	return cpu_to_le32(csum);
985 }
986 
987 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
988 {
989 	struct mdp_superblock_1 *sb;
990 	int ret;
991 	sector_t sb_offset;
992 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
993 	int bmask;
994 
995 	/*
996 	 * Calculate the position of the superblock.
997 	 * It is always aligned to a 4K boundary and
998 	 * depeding on minor_version, it can be:
999 	 * 0: At least 8K, but less than 12K, from end of device
1000 	 * 1: At start of device
1001 	 * 2: 4K from start of device.
1002 	 */
1003 	switch(minor_version) {
1004 	case 0:
1005 		sb_offset = rdev->bdev->bd_inode->i_size >> 9;
1006 		sb_offset -= 8*2;
1007 		sb_offset &= ~(sector_t)(4*2-1);
1008 		/* convert from sectors to K */
1009 		sb_offset /= 2;
1010 		break;
1011 	case 1:
1012 		sb_offset = 0;
1013 		break;
1014 	case 2:
1015 		sb_offset = 4;
1016 		break;
1017 	default:
1018 		return -EINVAL;
1019 	}
1020 	rdev->sb_offset = sb_offset;
1021 
1022 	/* superblock is rarely larger than 1K, but it can be larger,
1023 	 * and it is safe to read 4k, so we do that
1024 	 */
1025 	ret = read_disk_sb(rdev, 4096);
1026 	if (ret) return ret;
1027 
1028 
1029 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1030 
1031 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1032 	    sb->major_version != cpu_to_le32(1) ||
1033 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1034 	    le64_to_cpu(sb->super_offset) != (rdev->sb_offset<<1) ||
1035 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1036 		return -EINVAL;
1037 
1038 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1039 		printk("md: invalid superblock checksum on %s\n",
1040 			bdevname(rdev->bdev,b));
1041 		return -EINVAL;
1042 	}
1043 	if (le64_to_cpu(sb->data_size) < 10) {
1044 		printk("md: data_size too small on %s\n",
1045 		       bdevname(rdev->bdev,b));
1046 		return -EINVAL;
1047 	}
1048 	rdev->preferred_minor = 0xffff;
1049 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1050 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1051 
1052 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1053 	bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
1054 	if (rdev->sb_size & bmask)
1055 		rdev-> sb_size = (rdev->sb_size | bmask)+1;
1056 
1057 	if (refdev == 0)
1058 		ret = 1;
1059 	else {
1060 		__u64 ev1, ev2;
1061 		struct mdp_superblock_1 *refsb =
1062 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1063 
1064 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1065 		    sb->level != refsb->level ||
1066 		    sb->layout != refsb->layout ||
1067 		    sb->chunksize != refsb->chunksize) {
1068 			printk(KERN_WARNING "md: %s has strangely different"
1069 				" superblock to %s\n",
1070 				bdevname(rdev->bdev,b),
1071 				bdevname(refdev->bdev,b2));
1072 			return -EINVAL;
1073 		}
1074 		ev1 = le64_to_cpu(sb->events);
1075 		ev2 = le64_to_cpu(refsb->events);
1076 
1077 		if (ev1 > ev2)
1078 			ret = 1;
1079 		else
1080 			ret = 0;
1081 	}
1082 	if (minor_version)
1083 		rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
1084 	else
1085 		rdev->size = rdev->sb_offset;
1086 	if (rdev->size < le64_to_cpu(sb->data_size)/2)
1087 		return -EINVAL;
1088 	rdev->size = le64_to_cpu(sb->data_size)/2;
1089 	if (le32_to_cpu(sb->chunksize))
1090 		rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
1091 
1092 	if (le32_to_cpu(sb->size) > rdev->size*2)
1093 		return -EINVAL;
1094 	return ret;
1095 }
1096 
1097 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1098 {
1099 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1100 
1101 	rdev->raid_disk = -1;
1102 	rdev->flags = 0;
1103 	if (mddev->raid_disks == 0) {
1104 		mddev->major_version = 1;
1105 		mddev->patch_version = 0;
1106 		mddev->persistent = 1;
1107 		mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
1108 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1109 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1110 		mddev->level = le32_to_cpu(sb->level);
1111 		mddev->clevel[0] = 0;
1112 		mddev->layout = le32_to_cpu(sb->layout);
1113 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1114 		mddev->size = le64_to_cpu(sb->size)/2;
1115 		mddev->events = le64_to_cpu(sb->events);
1116 		mddev->bitmap_offset = 0;
1117 		mddev->default_bitmap_offset = 1024 >> 9;
1118 
1119 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1120 		memcpy(mddev->uuid, sb->set_uuid, 16);
1121 
1122 		mddev->max_disks =  (4096-256)/2;
1123 
1124 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1125 		    mddev->bitmap_file == NULL ) {
1126 			if (mddev->level != 1 && mddev->level != 5 && mddev->level != 6
1127 			    && mddev->level != 10) {
1128 				printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
1129 				return -EINVAL;
1130 			}
1131 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1132 		}
1133 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1134 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1135 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1136 			mddev->new_level = le32_to_cpu(sb->new_level);
1137 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1138 			mddev->new_chunk = le32_to_cpu(sb->new_chunk)<<9;
1139 		} else {
1140 			mddev->reshape_position = MaxSector;
1141 			mddev->delta_disks = 0;
1142 			mddev->new_level = mddev->level;
1143 			mddev->new_layout = mddev->layout;
1144 			mddev->new_chunk = mddev->chunk_size;
1145 		}
1146 
1147 	} else if (mddev->pers == NULL) {
1148 		/* Insist of good event counter while assembling */
1149 		__u64 ev1 = le64_to_cpu(sb->events);
1150 		++ev1;
1151 		if (ev1 < mddev->events)
1152 			return -EINVAL;
1153 	} else if (mddev->bitmap) {
1154 		/* If adding to array with a bitmap, then we can accept an
1155 		 * older device, but not too old.
1156 		 */
1157 		__u64 ev1 = le64_to_cpu(sb->events);
1158 		if (ev1 < mddev->bitmap->events_cleared)
1159 			return 0;
1160 	} else /* just a hot-add of a new device, leave raid_disk at -1 */
1161 		return 0;
1162 
1163 	if (mddev->level != LEVEL_MULTIPATH) {
1164 		int role;
1165 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1166 		role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1167 		switch(role) {
1168 		case 0xffff: /* spare */
1169 			break;
1170 		case 0xfffe: /* faulty */
1171 			set_bit(Faulty, &rdev->flags);
1172 			break;
1173 		default:
1174 			set_bit(In_sync, &rdev->flags);
1175 			rdev->raid_disk = role;
1176 			break;
1177 		}
1178 		if (sb->devflags & WriteMostly1)
1179 			set_bit(WriteMostly, &rdev->flags);
1180 	} else /* MULTIPATH are always insync */
1181 		set_bit(In_sync, &rdev->flags);
1182 
1183 	return 0;
1184 }
1185 
1186 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1187 {
1188 	struct mdp_superblock_1 *sb;
1189 	struct list_head *tmp;
1190 	mdk_rdev_t *rdev2;
1191 	int max_dev, i;
1192 	/* make rdev->sb match mddev and rdev data. */
1193 
1194 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1195 
1196 	sb->feature_map = 0;
1197 	sb->pad0 = 0;
1198 	memset(sb->pad1, 0, sizeof(sb->pad1));
1199 	memset(sb->pad2, 0, sizeof(sb->pad2));
1200 	memset(sb->pad3, 0, sizeof(sb->pad3));
1201 
1202 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1203 	sb->events = cpu_to_le64(mddev->events);
1204 	if (mddev->in_sync)
1205 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1206 	else
1207 		sb->resync_offset = cpu_to_le64(0);
1208 
1209 	sb->cnt_corrected_read = atomic_read(&rdev->corrected_errors);
1210 
1211 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1212 	sb->size = cpu_to_le64(mddev->size<<1);
1213 
1214 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1215 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1216 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1217 	}
1218 	if (mddev->reshape_position != MaxSector) {
1219 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1220 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1221 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1222 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1223 		sb->new_level = cpu_to_le32(mddev->new_level);
1224 		sb->new_chunk = cpu_to_le32(mddev->new_chunk>>9);
1225 	}
1226 
1227 	max_dev = 0;
1228 	ITERATE_RDEV(mddev,rdev2,tmp)
1229 		if (rdev2->desc_nr+1 > max_dev)
1230 			max_dev = rdev2->desc_nr+1;
1231 
1232 	sb->max_dev = cpu_to_le32(max_dev);
1233 	for (i=0; i<max_dev;i++)
1234 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1235 
1236 	ITERATE_RDEV(mddev,rdev2,tmp) {
1237 		i = rdev2->desc_nr;
1238 		if (test_bit(Faulty, &rdev2->flags))
1239 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1240 		else if (test_bit(In_sync, &rdev2->flags))
1241 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1242 		else
1243 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1244 	}
1245 
1246 	sb->recovery_offset = cpu_to_le64(0); /* not supported yet */
1247 	sb->sb_csum = calc_sb_1_csum(sb);
1248 }
1249 
1250 
1251 static struct super_type super_types[] = {
1252 	[0] = {
1253 		.name	= "0.90.0",
1254 		.owner	= THIS_MODULE,
1255 		.load_super	= super_90_load,
1256 		.validate_super	= super_90_validate,
1257 		.sync_super	= super_90_sync,
1258 	},
1259 	[1] = {
1260 		.name	= "md-1",
1261 		.owner	= THIS_MODULE,
1262 		.load_super	= super_1_load,
1263 		.validate_super	= super_1_validate,
1264 		.sync_super	= super_1_sync,
1265 	},
1266 };
1267 
1268 static mdk_rdev_t * match_dev_unit(mddev_t *mddev, mdk_rdev_t *dev)
1269 {
1270 	struct list_head *tmp;
1271 	mdk_rdev_t *rdev;
1272 
1273 	ITERATE_RDEV(mddev,rdev,tmp)
1274 		if (rdev->bdev->bd_contains == dev->bdev->bd_contains)
1275 			return rdev;
1276 
1277 	return NULL;
1278 }
1279 
1280 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1281 {
1282 	struct list_head *tmp;
1283 	mdk_rdev_t *rdev;
1284 
1285 	ITERATE_RDEV(mddev1,rdev,tmp)
1286 		if (match_dev_unit(mddev2, rdev))
1287 			return 1;
1288 
1289 	return 0;
1290 }
1291 
1292 static LIST_HEAD(pending_raid_disks);
1293 
1294 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1295 {
1296 	mdk_rdev_t *same_pdev;
1297 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1298 	struct kobject *ko;
1299 	char *s;
1300 
1301 	if (rdev->mddev) {
1302 		MD_BUG();
1303 		return -EINVAL;
1304 	}
1305 	/* make sure rdev->size exceeds mddev->size */
1306 	if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
1307 		if (mddev->pers)
1308 			/* Cannot change size, so fail */
1309 			return -ENOSPC;
1310 		else
1311 			mddev->size = rdev->size;
1312 	}
1313 	same_pdev = match_dev_unit(mddev, rdev);
1314 	if (same_pdev)
1315 		printk(KERN_WARNING
1316 			"%s: WARNING: %s appears to be on the same physical"
1317 	 		" disk as %s. True\n     protection against single-disk"
1318 			" failure might be compromised.\n",
1319 			mdname(mddev), bdevname(rdev->bdev,b),
1320 			bdevname(same_pdev->bdev,b2));
1321 
1322 	/* Verify rdev->desc_nr is unique.
1323 	 * If it is -1, assign a free number, else
1324 	 * check number is not in use
1325 	 */
1326 	if (rdev->desc_nr < 0) {
1327 		int choice = 0;
1328 		if (mddev->pers) choice = mddev->raid_disks;
1329 		while (find_rdev_nr(mddev, choice))
1330 			choice++;
1331 		rdev->desc_nr = choice;
1332 	} else {
1333 		if (find_rdev_nr(mddev, rdev->desc_nr))
1334 			return -EBUSY;
1335 	}
1336 	bdevname(rdev->bdev,b);
1337 	if (kobject_set_name(&rdev->kobj, "dev-%s", b) < 0)
1338 		return -ENOMEM;
1339 	while ( (s=strchr(rdev->kobj.k_name, '/')) != NULL)
1340 		*s = '!';
1341 
1342 	list_add(&rdev->same_set, &mddev->disks);
1343 	rdev->mddev = mddev;
1344 	printk(KERN_INFO "md: bind<%s>\n", b);
1345 
1346 	rdev->kobj.parent = &mddev->kobj;
1347 	kobject_add(&rdev->kobj);
1348 
1349 	if (rdev->bdev->bd_part)
1350 		ko = &rdev->bdev->bd_part->kobj;
1351 	else
1352 		ko = &rdev->bdev->bd_disk->kobj;
1353 	sysfs_create_link(&rdev->kobj, ko, "block");
1354 	bd_claim_by_disk(rdev->bdev, rdev, mddev->gendisk);
1355 	return 0;
1356 }
1357 
1358 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1359 {
1360 	char b[BDEVNAME_SIZE];
1361 	if (!rdev->mddev) {
1362 		MD_BUG();
1363 		return;
1364 	}
1365 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1366 	list_del_init(&rdev->same_set);
1367 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1368 	rdev->mddev = NULL;
1369 	sysfs_remove_link(&rdev->kobj, "block");
1370 	kobject_del(&rdev->kobj);
1371 }
1372 
1373 /*
1374  * prevent the device from being mounted, repartitioned or
1375  * otherwise reused by a RAID array (or any other kernel
1376  * subsystem), by bd_claiming the device.
1377  */
1378 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev)
1379 {
1380 	int err = 0;
1381 	struct block_device *bdev;
1382 	char b[BDEVNAME_SIZE];
1383 
1384 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1385 	if (IS_ERR(bdev)) {
1386 		printk(KERN_ERR "md: could not open %s.\n",
1387 			__bdevname(dev, b));
1388 		return PTR_ERR(bdev);
1389 	}
1390 	err = bd_claim(bdev, rdev);
1391 	if (err) {
1392 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1393 			bdevname(bdev, b));
1394 		blkdev_put(bdev);
1395 		return err;
1396 	}
1397 	rdev->bdev = bdev;
1398 	return err;
1399 }
1400 
1401 static void unlock_rdev(mdk_rdev_t *rdev)
1402 {
1403 	struct block_device *bdev = rdev->bdev;
1404 	rdev->bdev = NULL;
1405 	if (!bdev)
1406 		MD_BUG();
1407 	bd_release(bdev);
1408 	blkdev_put(bdev);
1409 }
1410 
1411 void md_autodetect_dev(dev_t dev);
1412 
1413 static void export_rdev(mdk_rdev_t * rdev)
1414 {
1415 	char b[BDEVNAME_SIZE];
1416 	printk(KERN_INFO "md: export_rdev(%s)\n",
1417 		bdevname(rdev->bdev,b));
1418 	if (rdev->mddev)
1419 		MD_BUG();
1420 	free_disk_sb(rdev);
1421 	list_del_init(&rdev->same_set);
1422 #ifndef MODULE
1423 	md_autodetect_dev(rdev->bdev->bd_dev);
1424 #endif
1425 	unlock_rdev(rdev);
1426 	kobject_put(&rdev->kobj);
1427 }
1428 
1429 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1430 {
1431 	unbind_rdev_from_array(rdev);
1432 	export_rdev(rdev);
1433 }
1434 
1435 static void export_array(mddev_t *mddev)
1436 {
1437 	struct list_head *tmp;
1438 	mdk_rdev_t *rdev;
1439 
1440 	ITERATE_RDEV(mddev,rdev,tmp) {
1441 		if (!rdev->mddev) {
1442 			MD_BUG();
1443 			continue;
1444 		}
1445 		kick_rdev_from_array(rdev);
1446 	}
1447 	if (!list_empty(&mddev->disks))
1448 		MD_BUG();
1449 	mddev->raid_disks = 0;
1450 	mddev->major_version = 0;
1451 }
1452 
1453 static void print_desc(mdp_disk_t *desc)
1454 {
1455 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1456 		desc->major,desc->minor,desc->raid_disk,desc->state);
1457 }
1458 
1459 static void print_sb(mdp_super_t *sb)
1460 {
1461 	int i;
1462 
1463 	printk(KERN_INFO
1464 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1465 		sb->major_version, sb->minor_version, sb->patch_version,
1466 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1467 		sb->ctime);
1468 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1469 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1470 		sb->md_minor, sb->layout, sb->chunk_size);
1471 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1472 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1473 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1474 		sb->failed_disks, sb->spare_disks,
1475 		sb->sb_csum, (unsigned long)sb->events_lo);
1476 
1477 	printk(KERN_INFO);
1478 	for (i = 0; i < MD_SB_DISKS; i++) {
1479 		mdp_disk_t *desc;
1480 
1481 		desc = sb->disks + i;
1482 		if (desc->number || desc->major || desc->minor ||
1483 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1484 			printk("     D %2d: ", i);
1485 			print_desc(desc);
1486 		}
1487 	}
1488 	printk(KERN_INFO "md:     THIS: ");
1489 	print_desc(&sb->this_disk);
1490 
1491 }
1492 
1493 static void print_rdev(mdk_rdev_t *rdev)
1494 {
1495 	char b[BDEVNAME_SIZE];
1496 	printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
1497 		bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
1498 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1499 	        rdev->desc_nr);
1500 	if (rdev->sb_loaded) {
1501 		printk(KERN_INFO "md: rdev superblock:\n");
1502 		print_sb((mdp_super_t*)page_address(rdev->sb_page));
1503 	} else
1504 		printk(KERN_INFO "md: no rdev superblock!\n");
1505 }
1506 
1507 void md_print_devices(void)
1508 {
1509 	struct list_head *tmp, *tmp2;
1510 	mdk_rdev_t *rdev;
1511 	mddev_t *mddev;
1512 	char b[BDEVNAME_SIZE];
1513 
1514 	printk("\n");
1515 	printk("md:	**********************************\n");
1516 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1517 	printk("md:	**********************************\n");
1518 	ITERATE_MDDEV(mddev,tmp) {
1519 
1520 		if (mddev->bitmap)
1521 			bitmap_print_sb(mddev->bitmap);
1522 		else
1523 			printk("%s: ", mdname(mddev));
1524 		ITERATE_RDEV(mddev,rdev,tmp2)
1525 			printk("<%s>", bdevname(rdev->bdev,b));
1526 		printk("\n");
1527 
1528 		ITERATE_RDEV(mddev,rdev,tmp2)
1529 			print_rdev(rdev);
1530 	}
1531 	printk("md:	**********************************\n");
1532 	printk("\n");
1533 }
1534 
1535 
1536 static void sync_sbs(mddev_t * mddev)
1537 {
1538 	mdk_rdev_t *rdev;
1539 	struct list_head *tmp;
1540 
1541 	ITERATE_RDEV(mddev,rdev,tmp) {
1542 		super_types[mddev->major_version].
1543 			sync_super(mddev, rdev);
1544 		rdev->sb_loaded = 1;
1545 	}
1546 }
1547 
1548 void md_update_sb(mddev_t * mddev)
1549 {
1550 	int err;
1551 	struct list_head *tmp;
1552 	mdk_rdev_t *rdev;
1553 	int sync_req;
1554 
1555 repeat:
1556 	spin_lock_irq(&mddev->write_lock);
1557 	sync_req = mddev->in_sync;
1558 	mddev->utime = get_seconds();
1559 	mddev->events ++;
1560 
1561 	if (!mddev->events) {
1562 		/*
1563 		 * oops, this 64-bit counter should never wrap.
1564 		 * Either we are in around ~1 trillion A.C., assuming
1565 		 * 1 reboot per second, or we have a bug:
1566 		 */
1567 		MD_BUG();
1568 		mddev->events --;
1569 	}
1570 	mddev->sb_dirty = 2;
1571 	sync_sbs(mddev);
1572 
1573 	/*
1574 	 * do not write anything to disk if using
1575 	 * nonpersistent superblocks
1576 	 */
1577 	if (!mddev->persistent) {
1578 		mddev->sb_dirty = 0;
1579 		spin_unlock_irq(&mddev->write_lock);
1580 		wake_up(&mddev->sb_wait);
1581 		return;
1582 	}
1583 	spin_unlock_irq(&mddev->write_lock);
1584 
1585 	dprintk(KERN_INFO
1586 		"md: updating %s RAID superblock on device (in sync %d)\n",
1587 		mdname(mddev),mddev->in_sync);
1588 
1589 	err = bitmap_update_sb(mddev->bitmap);
1590 	ITERATE_RDEV(mddev,rdev,tmp) {
1591 		char b[BDEVNAME_SIZE];
1592 		dprintk(KERN_INFO "md: ");
1593 		if (test_bit(Faulty, &rdev->flags))
1594 			dprintk("(skipping faulty ");
1595 
1596 		dprintk("%s ", bdevname(rdev->bdev,b));
1597 		if (!test_bit(Faulty, &rdev->flags)) {
1598 			md_super_write(mddev,rdev,
1599 				       rdev->sb_offset<<1, rdev->sb_size,
1600 				       rdev->sb_page);
1601 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1602 				bdevname(rdev->bdev,b),
1603 				(unsigned long long)rdev->sb_offset);
1604 
1605 		} else
1606 			dprintk(")\n");
1607 		if (mddev->level == LEVEL_MULTIPATH)
1608 			/* only need to write one superblock... */
1609 			break;
1610 	}
1611 	md_super_wait(mddev);
1612 	/* if there was a failure, sb_dirty was set to 1, and we re-write super */
1613 
1614 	spin_lock_irq(&mddev->write_lock);
1615 	if (mddev->in_sync != sync_req|| mddev->sb_dirty == 1) {
1616 		/* have to write it out again */
1617 		spin_unlock_irq(&mddev->write_lock);
1618 		goto repeat;
1619 	}
1620 	mddev->sb_dirty = 0;
1621 	spin_unlock_irq(&mddev->write_lock);
1622 	wake_up(&mddev->sb_wait);
1623 
1624 }
1625 EXPORT_SYMBOL_GPL(md_update_sb);
1626 
1627 /* words written to sysfs files may, or my not, be \n terminated.
1628  * We want to accept with case. For this we use cmd_match.
1629  */
1630 static int cmd_match(const char *cmd, const char *str)
1631 {
1632 	/* See if cmd, written into a sysfs file, matches
1633 	 * str.  They must either be the same, or cmd can
1634 	 * have a trailing newline
1635 	 */
1636 	while (*cmd && *str && *cmd == *str) {
1637 		cmd++;
1638 		str++;
1639 	}
1640 	if (*cmd == '\n')
1641 		cmd++;
1642 	if (*str || *cmd)
1643 		return 0;
1644 	return 1;
1645 }
1646 
1647 struct rdev_sysfs_entry {
1648 	struct attribute attr;
1649 	ssize_t (*show)(mdk_rdev_t *, char *);
1650 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
1651 };
1652 
1653 static ssize_t
1654 state_show(mdk_rdev_t *rdev, char *page)
1655 {
1656 	char *sep = "";
1657 	int len=0;
1658 
1659 	if (test_bit(Faulty, &rdev->flags)) {
1660 		len+= sprintf(page+len, "%sfaulty",sep);
1661 		sep = ",";
1662 	}
1663 	if (test_bit(In_sync, &rdev->flags)) {
1664 		len += sprintf(page+len, "%sin_sync",sep);
1665 		sep = ",";
1666 	}
1667 	if (!test_bit(Faulty, &rdev->flags) &&
1668 	    !test_bit(In_sync, &rdev->flags)) {
1669 		len += sprintf(page+len, "%sspare", sep);
1670 		sep = ",";
1671 	}
1672 	return len+sprintf(page+len, "\n");
1673 }
1674 
1675 static struct rdev_sysfs_entry
1676 rdev_state = __ATTR_RO(state);
1677 
1678 static ssize_t
1679 super_show(mdk_rdev_t *rdev, char *page)
1680 {
1681 	if (rdev->sb_loaded && rdev->sb_size) {
1682 		memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
1683 		return rdev->sb_size;
1684 	} else
1685 		return 0;
1686 }
1687 static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
1688 
1689 static ssize_t
1690 errors_show(mdk_rdev_t *rdev, char *page)
1691 {
1692 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
1693 }
1694 
1695 static ssize_t
1696 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1697 {
1698 	char *e;
1699 	unsigned long n = simple_strtoul(buf, &e, 10);
1700 	if (*buf && (*e == 0 || *e == '\n')) {
1701 		atomic_set(&rdev->corrected_errors, n);
1702 		return len;
1703 	}
1704 	return -EINVAL;
1705 }
1706 static struct rdev_sysfs_entry rdev_errors =
1707 __ATTR(errors, 0644, errors_show, errors_store);
1708 
1709 static ssize_t
1710 slot_show(mdk_rdev_t *rdev, char *page)
1711 {
1712 	if (rdev->raid_disk < 0)
1713 		return sprintf(page, "none\n");
1714 	else
1715 		return sprintf(page, "%d\n", rdev->raid_disk);
1716 }
1717 
1718 static ssize_t
1719 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1720 {
1721 	char *e;
1722 	int slot = simple_strtoul(buf, &e, 10);
1723 	if (strncmp(buf, "none", 4)==0)
1724 		slot = -1;
1725 	else if (e==buf || (*e && *e!= '\n'))
1726 		return -EINVAL;
1727 	if (rdev->mddev->pers)
1728 		/* Cannot set slot in active array (yet) */
1729 		return -EBUSY;
1730 	if (slot >= rdev->mddev->raid_disks)
1731 		return -ENOSPC;
1732 	rdev->raid_disk = slot;
1733 	/* assume it is working */
1734 	rdev->flags = 0;
1735 	set_bit(In_sync, &rdev->flags);
1736 	return len;
1737 }
1738 
1739 
1740 static struct rdev_sysfs_entry rdev_slot =
1741 __ATTR(slot, 0644, slot_show, slot_store);
1742 
1743 static ssize_t
1744 offset_show(mdk_rdev_t *rdev, char *page)
1745 {
1746 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
1747 }
1748 
1749 static ssize_t
1750 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1751 {
1752 	char *e;
1753 	unsigned long long offset = simple_strtoull(buf, &e, 10);
1754 	if (e==buf || (*e && *e != '\n'))
1755 		return -EINVAL;
1756 	if (rdev->mddev->pers)
1757 		return -EBUSY;
1758 	rdev->data_offset = offset;
1759 	return len;
1760 }
1761 
1762 static struct rdev_sysfs_entry rdev_offset =
1763 __ATTR(offset, 0644, offset_show, offset_store);
1764 
1765 static ssize_t
1766 rdev_size_show(mdk_rdev_t *rdev, char *page)
1767 {
1768 	return sprintf(page, "%llu\n", (unsigned long long)rdev->size);
1769 }
1770 
1771 static ssize_t
1772 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1773 {
1774 	char *e;
1775 	unsigned long long size = simple_strtoull(buf, &e, 10);
1776 	if (e==buf || (*e && *e != '\n'))
1777 		return -EINVAL;
1778 	if (rdev->mddev->pers)
1779 		return -EBUSY;
1780 	rdev->size = size;
1781 	if (size < rdev->mddev->size || rdev->mddev->size == 0)
1782 		rdev->mddev->size = size;
1783 	return len;
1784 }
1785 
1786 static struct rdev_sysfs_entry rdev_size =
1787 __ATTR(size, 0644, rdev_size_show, rdev_size_store);
1788 
1789 static struct attribute *rdev_default_attrs[] = {
1790 	&rdev_state.attr,
1791 	&rdev_super.attr,
1792 	&rdev_errors.attr,
1793 	&rdev_slot.attr,
1794 	&rdev_offset.attr,
1795 	&rdev_size.attr,
1796 	NULL,
1797 };
1798 static ssize_t
1799 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
1800 {
1801 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1802 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1803 
1804 	if (!entry->show)
1805 		return -EIO;
1806 	return entry->show(rdev, page);
1807 }
1808 
1809 static ssize_t
1810 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
1811 	      const char *page, size_t length)
1812 {
1813 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
1814 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
1815 
1816 	if (!entry->store)
1817 		return -EIO;
1818 	return entry->store(rdev, page, length);
1819 }
1820 
1821 static void rdev_free(struct kobject *ko)
1822 {
1823 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
1824 	kfree(rdev);
1825 }
1826 static struct sysfs_ops rdev_sysfs_ops = {
1827 	.show		= rdev_attr_show,
1828 	.store		= rdev_attr_store,
1829 };
1830 static struct kobj_type rdev_ktype = {
1831 	.release	= rdev_free,
1832 	.sysfs_ops	= &rdev_sysfs_ops,
1833 	.default_attrs	= rdev_default_attrs,
1834 };
1835 
1836 /*
1837  * Import a device. If 'super_format' >= 0, then sanity check the superblock
1838  *
1839  * mark the device faulty if:
1840  *
1841  *   - the device is nonexistent (zero size)
1842  *   - the device has no valid superblock
1843  *
1844  * a faulty rdev _never_ has rdev->sb set.
1845  */
1846 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
1847 {
1848 	char b[BDEVNAME_SIZE];
1849 	int err;
1850 	mdk_rdev_t *rdev;
1851 	sector_t size;
1852 
1853 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
1854 	if (!rdev) {
1855 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
1856 		return ERR_PTR(-ENOMEM);
1857 	}
1858 
1859 	if ((err = alloc_disk_sb(rdev)))
1860 		goto abort_free;
1861 
1862 	err = lock_rdev(rdev, newdev);
1863 	if (err)
1864 		goto abort_free;
1865 
1866 	rdev->kobj.parent = NULL;
1867 	rdev->kobj.ktype = &rdev_ktype;
1868 	kobject_init(&rdev->kobj);
1869 
1870 	rdev->desc_nr = -1;
1871 	rdev->flags = 0;
1872 	rdev->data_offset = 0;
1873 	atomic_set(&rdev->nr_pending, 0);
1874 	atomic_set(&rdev->read_errors, 0);
1875 	atomic_set(&rdev->corrected_errors, 0);
1876 
1877 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
1878 	if (!size) {
1879 		printk(KERN_WARNING
1880 			"md: %s has zero or unknown size, marking faulty!\n",
1881 			bdevname(rdev->bdev,b));
1882 		err = -EINVAL;
1883 		goto abort_free;
1884 	}
1885 
1886 	if (super_format >= 0) {
1887 		err = super_types[super_format].
1888 			load_super(rdev, NULL, super_minor);
1889 		if (err == -EINVAL) {
1890 			printk(KERN_WARNING
1891 				"md: %s has invalid sb, not importing!\n",
1892 				bdevname(rdev->bdev,b));
1893 			goto abort_free;
1894 		}
1895 		if (err < 0) {
1896 			printk(KERN_WARNING
1897 				"md: could not read %s's sb, not importing!\n",
1898 				bdevname(rdev->bdev,b));
1899 			goto abort_free;
1900 		}
1901 	}
1902 	INIT_LIST_HEAD(&rdev->same_set);
1903 
1904 	return rdev;
1905 
1906 abort_free:
1907 	if (rdev->sb_page) {
1908 		if (rdev->bdev)
1909 			unlock_rdev(rdev);
1910 		free_disk_sb(rdev);
1911 	}
1912 	kfree(rdev);
1913 	return ERR_PTR(err);
1914 }
1915 
1916 /*
1917  * Check a full RAID array for plausibility
1918  */
1919 
1920 
1921 static void analyze_sbs(mddev_t * mddev)
1922 {
1923 	int i;
1924 	struct list_head *tmp;
1925 	mdk_rdev_t *rdev, *freshest;
1926 	char b[BDEVNAME_SIZE];
1927 
1928 	freshest = NULL;
1929 	ITERATE_RDEV(mddev,rdev,tmp)
1930 		switch (super_types[mddev->major_version].
1931 			load_super(rdev, freshest, mddev->minor_version)) {
1932 		case 1:
1933 			freshest = rdev;
1934 			break;
1935 		case 0:
1936 			break;
1937 		default:
1938 			printk( KERN_ERR \
1939 				"md: fatal superblock inconsistency in %s"
1940 				" -- removing from array\n",
1941 				bdevname(rdev->bdev,b));
1942 			kick_rdev_from_array(rdev);
1943 		}
1944 
1945 
1946 	super_types[mddev->major_version].
1947 		validate_super(mddev, freshest);
1948 
1949 	i = 0;
1950 	ITERATE_RDEV(mddev,rdev,tmp) {
1951 		if (rdev != freshest)
1952 			if (super_types[mddev->major_version].
1953 			    validate_super(mddev, rdev)) {
1954 				printk(KERN_WARNING "md: kicking non-fresh %s"
1955 					" from array!\n",
1956 					bdevname(rdev->bdev,b));
1957 				kick_rdev_from_array(rdev);
1958 				continue;
1959 			}
1960 		if (mddev->level == LEVEL_MULTIPATH) {
1961 			rdev->desc_nr = i++;
1962 			rdev->raid_disk = rdev->desc_nr;
1963 			set_bit(In_sync, &rdev->flags);
1964 		}
1965 	}
1966 
1967 
1968 
1969 	if (mddev->recovery_cp != MaxSector &&
1970 	    mddev->level >= 1)
1971 		printk(KERN_ERR "md: %s: raid array is not clean"
1972 		       " -- starting background reconstruction\n",
1973 		       mdname(mddev));
1974 
1975 }
1976 
1977 static ssize_t
1978 level_show(mddev_t *mddev, char *page)
1979 {
1980 	struct mdk_personality *p = mddev->pers;
1981 	if (p)
1982 		return sprintf(page, "%s\n", p->name);
1983 	else if (mddev->clevel[0])
1984 		return sprintf(page, "%s\n", mddev->clevel);
1985 	else if (mddev->level != LEVEL_NONE)
1986 		return sprintf(page, "%d\n", mddev->level);
1987 	else
1988 		return 0;
1989 }
1990 
1991 static ssize_t
1992 level_store(mddev_t *mddev, const char *buf, size_t len)
1993 {
1994 	int rv = len;
1995 	if (mddev->pers)
1996 		return -EBUSY;
1997 	if (len == 0)
1998 		return 0;
1999 	if (len >= sizeof(mddev->clevel))
2000 		return -ENOSPC;
2001 	strncpy(mddev->clevel, buf, len);
2002 	if (mddev->clevel[len-1] == '\n')
2003 		len--;
2004 	mddev->clevel[len] = 0;
2005 	mddev->level = LEVEL_NONE;
2006 	return rv;
2007 }
2008 
2009 static struct md_sysfs_entry md_level =
2010 __ATTR(level, 0644, level_show, level_store);
2011 
2012 static ssize_t
2013 raid_disks_show(mddev_t *mddev, char *page)
2014 {
2015 	if (mddev->raid_disks == 0)
2016 		return 0;
2017 	return sprintf(page, "%d\n", mddev->raid_disks);
2018 }
2019 
2020 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2021 
2022 static ssize_t
2023 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2024 {
2025 	/* can only set raid_disks if array is not yet active */
2026 	char *e;
2027 	int rv = 0;
2028 	unsigned long n = simple_strtoul(buf, &e, 10);
2029 
2030 	if (!*buf || (*e && *e != '\n'))
2031 		return -EINVAL;
2032 
2033 	if (mddev->pers)
2034 		rv = update_raid_disks(mddev, n);
2035 	else
2036 		mddev->raid_disks = n;
2037 	return rv ? rv : len;
2038 }
2039 static struct md_sysfs_entry md_raid_disks =
2040 __ATTR(raid_disks, 0644, raid_disks_show, raid_disks_store);
2041 
2042 static ssize_t
2043 chunk_size_show(mddev_t *mddev, char *page)
2044 {
2045 	return sprintf(page, "%d\n", mddev->chunk_size);
2046 }
2047 
2048 static ssize_t
2049 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2050 {
2051 	/* can only set chunk_size if array is not yet active */
2052 	char *e;
2053 	unsigned long n = simple_strtoul(buf, &e, 10);
2054 
2055 	if (mddev->pers)
2056 		return -EBUSY;
2057 	if (!*buf || (*e && *e != '\n'))
2058 		return -EINVAL;
2059 
2060 	mddev->chunk_size = n;
2061 	return len;
2062 }
2063 static struct md_sysfs_entry md_chunk_size =
2064 __ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store);
2065 
2066 static ssize_t
2067 null_show(mddev_t *mddev, char *page)
2068 {
2069 	return -EINVAL;
2070 }
2071 
2072 static ssize_t
2073 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
2074 {
2075 	/* buf must be %d:%d\n? giving major and minor numbers */
2076 	/* The new device is added to the array.
2077 	 * If the array has a persistent superblock, we read the
2078 	 * superblock to initialise info and check validity.
2079 	 * Otherwise, only checking done is that in bind_rdev_to_array,
2080 	 * which mainly checks size.
2081 	 */
2082 	char *e;
2083 	int major = simple_strtoul(buf, &e, 10);
2084 	int minor;
2085 	dev_t dev;
2086 	mdk_rdev_t *rdev;
2087 	int err;
2088 
2089 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
2090 		return -EINVAL;
2091 	minor = simple_strtoul(e+1, &e, 10);
2092 	if (*e && *e != '\n')
2093 		return -EINVAL;
2094 	dev = MKDEV(major, minor);
2095 	if (major != MAJOR(dev) ||
2096 	    minor != MINOR(dev))
2097 		return -EOVERFLOW;
2098 
2099 
2100 	if (mddev->persistent) {
2101 		rdev = md_import_device(dev, mddev->major_version,
2102 					mddev->minor_version);
2103 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
2104 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
2105 						       mdk_rdev_t, same_set);
2106 			err = super_types[mddev->major_version]
2107 				.load_super(rdev, rdev0, mddev->minor_version);
2108 			if (err < 0)
2109 				goto out;
2110 		}
2111 	} else
2112 		rdev = md_import_device(dev, -1, -1);
2113 
2114 	if (IS_ERR(rdev))
2115 		return PTR_ERR(rdev);
2116 	err = bind_rdev_to_array(rdev, mddev);
2117  out:
2118 	if (err)
2119 		export_rdev(rdev);
2120 	return err ? err : len;
2121 }
2122 
2123 static struct md_sysfs_entry md_new_device =
2124 __ATTR(new_dev, 0200, null_show, new_dev_store);
2125 
2126 static ssize_t
2127 size_show(mddev_t *mddev, char *page)
2128 {
2129 	return sprintf(page, "%llu\n", (unsigned long long)mddev->size);
2130 }
2131 
2132 static int update_size(mddev_t *mddev, unsigned long size);
2133 
2134 static ssize_t
2135 size_store(mddev_t *mddev, const char *buf, size_t len)
2136 {
2137 	/* If array is inactive, we can reduce the component size, but
2138 	 * not increase it (except from 0).
2139 	 * If array is active, we can try an on-line resize
2140 	 */
2141 	char *e;
2142 	int err = 0;
2143 	unsigned long long size = simple_strtoull(buf, &e, 10);
2144 	if (!*buf || *buf == '\n' ||
2145 	    (*e && *e != '\n'))
2146 		return -EINVAL;
2147 
2148 	if (mddev->pers) {
2149 		err = update_size(mddev, size);
2150 		md_update_sb(mddev);
2151 	} else {
2152 		if (mddev->size == 0 ||
2153 		    mddev->size > size)
2154 			mddev->size = size;
2155 		else
2156 			err = -ENOSPC;
2157 	}
2158 	return err ? err : len;
2159 }
2160 
2161 static struct md_sysfs_entry md_size =
2162 __ATTR(component_size, 0644, size_show, size_store);
2163 
2164 
2165 /* Metdata version.
2166  * This is either 'none' for arrays with externally managed metadata,
2167  * or N.M for internally known formats
2168  */
2169 static ssize_t
2170 metadata_show(mddev_t *mddev, char *page)
2171 {
2172 	if (mddev->persistent)
2173 		return sprintf(page, "%d.%d\n",
2174 			       mddev->major_version, mddev->minor_version);
2175 	else
2176 		return sprintf(page, "none\n");
2177 }
2178 
2179 static ssize_t
2180 metadata_store(mddev_t *mddev, const char *buf, size_t len)
2181 {
2182 	int major, minor;
2183 	char *e;
2184 	if (!list_empty(&mddev->disks))
2185 		return -EBUSY;
2186 
2187 	if (cmd_match(buf, "none")) {
2188 		mddev->persistent = 0;
2189 		mddev->major_version = 0;
2190 		mddev->minor_version = 90;
2191 		return len;
2192 	}
2193 	major = simple_strtoul(buf, &e, 10);
2194 	if (e==buf || *e != '.')
2195 		return -EINVAL;
2196 	buf = e+1;
2197 	minor = simple_strtoul(buf, &e, 10);
2198 	if (e==buf || *e != '\n')
2199 		return -EINVAL;
2200 	if (major >= sizeof(super_types)/sizeof(super_types[0]) ||
2201 	    super_types[major].name == NULL)
2202 		return -ENOENT;
2203 	mddev->major_version = major;
2204 	mddev->minor_version = minor;
2205 	mddev->persistent = 1;
2206 	return len;
2207 }
2208 
2209 static struct md_sysfs_entry md_metadata =
2210 __ATTR(metadata_version, 0644, metadata_show, metadata_store);
2211 
2212 static ssize_t
2213 action_show(mddev_t *mddev, char *page)
2214 {
2215 	char *type = "idle";
2216 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2217 	    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) {
2218 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
2219 			type = "reshape";
2220 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2221 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2222 				type = "resync";
2223 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
2224 				type = "check";
2225 			else
2226 				type = "repair";
2227 		} else
2228 			type = "recover";
2229 	}
2230 	return sprintf(page, "%s\n", type);
2231 }
2232 
2233 static ssize_t
2234 action_store(mddev_t *mddev, const char *page, size_t len)
2235 {
2236 	if (!mddev->pers || !mddev->pers->sync_request)
2237 		return -EINVAL;
2238 
2239 	if (cmd_match(page, "idle")) {
2240 		if (mddev->sync_thread) {
2241 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2242 			md_unregister_thread(mddev->sync_thread);
2243 			mddev->sync_thread = NULL;
2244 			mddev->recovery = 0;
2245 		}
2246 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
2247 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
2248 		return -EBUSY;
2249 	else if (cmd_match(page, "resync") || cmd_match(page, "recover"))
2250 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2251 	else if (cmd_match(page, "reshape")) {
2252 		int err;
2253 		if (mddev->pers->start_reshape == NULL)
2254 			return -EINVAL;
2255 		err = mddev->pers->start_reshape(mddev);
2256 		if (err)
2257 			return err;
2258 	} else {
2259 		if (cmd_match(page, "check"))
2260 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
2261 		else if (cmd_match(page, "repair"))
2262 			return -EINVAL;
2263 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
2264 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
2265 	}
2266 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2267 	md_wakeup_thread(mddev->thread);
2268 	return len;
2269 }
2270 
2271 static ssize_t
2272 mismatch_cnt_show(mddev_t *mddev, char *page)
2273 {
2274 	return sprintf(page, "%llu\n",
2275 		       (unsigned long long) mddev->resync_mismatches);
2276 }
2277 
2278 static struct md_sysfs_entry
2279 md_scan_mode = __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
2280 
2281 
2282 static struct md_sysfs_entry
2283 md_mismatches = __ATTR_RO(mismatch_cnt);
2284 
2285 static ssize_t
2286 sync_min_show(mddev_t *mddev, char *page)
2287 {
2288 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
2289 		       mddev->sync_speed_min ? "local": "system");
2290 }
2291 
2292 static ssize_t
2293 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
2294 {
2295 	int min;
2296 	char *e;
2297 	if (strncmp(buf, "system", 6)==0) {
2298 		mddev->sync_speed_min = 0;
2299 		return len;
2300 	}
2301 	min = simple_strtoul(buf, &e, 10);
2302 	if (buf == e || (*e && *e != '\n') || min <= 0)
2303 		return -EINVAL;
2304 	mddev->sync_speed_min = min;
2305 	return len;
2306 }
2307 
2308 static struct md_sysfs_entry md_sync_min =
2309 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
2310 
2311 static ssize_t
2312 sync_max_show(mddev_t *mddev, char *page)
2313 {
2314 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
2315 		       mddev->sync_speed_max ? "local": "system");
2316 }
2317 
2318 static ssize_t
2319 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
2320 {
2321 	int max;
2322 	char *e;
2323 	if (strncmp(buf, "system", 6)==0) {
2324 		mddev->sync_speed_max = 0;
2325 		return len;
2326 	}
2327 	max = simple_strtoul(buf, &e, 10);
2328 	if (buf == e || (*e && *e != '\n') || max <= 0)
2329 		return -EINVAL;
2330 	mddev->sync_speed_max = max;
2331 	return len;
2332 }
2333 
2334 static struct md_sysfs_entry md_sync_max =
2335 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
2336 
2337 
2338 static ssize_t
2339 sync_speed_show(mddev_t *mddev, char *page)
2340 {
2341 	unsigned long resync, dt, db;
2342 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
2343 	dt = ((jiffies - mddev->resync_mark) / HZ);
2344 	if (!dt) dt++;
2345 	db = resync - (mddev->resync_mark_cnt);
2346 	return sprintf(page, "%ld\n", db/dt/2); /* K/sec */
2347 }
2348 
2349 static struct md_sysfs_entry
2350 md_sync_speed = __ATTR_RO(sync_speed);
2351 
2352 static ssize_t
2353 sync_completed_show(mddev_t *mddev, char *page)
2354 {
2355 	unsigned long max_blocks, resync;
2356 
2357 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2358 		max_blocks = mddev->resync_max_sectors;
2359 	else
2360 		max_blocks = mddev->size << 1;
2361 
2362 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
2363 	return sprintf(page, "%lu / %lu\n", resync, max_blocks);
2364 }
2365 
2366 static struct md_sysfs_entry
2367 md_sync_completed = __ATTR_RO(sync_completed);
2368 
2369 static ssize_t
2370 suspend_lo_show(mddev_t *mddev, char *page)
2371 {
2372 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
2373 }
2374 
2375 static ssize_t
2376 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
2377 {
2378 	char *e;
2379 	unsigned long long new = simple_strtoull(buf, &e, 10);
2380 
2381 	if (mddev->pers->quiesce == NULL)
2382 		return -EINVAL;
2383 	if (buf == e || (*e && *e != '\n'))
2384 		return -EINVAL;
2385 	if (new >= mddev->suspend_hi ||
2386 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
2387 		mddev->suspend_lo = new;
2388 		mddev->pers->quiesce(mddev, 2);
2389 		return len;
2390 	} else
2391 		return -EINVAL;
2392 }
2393 static struct md_sysfs_entry md_suspend_lo =
2394 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
2395 
2396 
2397 static ssize_t
2398 suspend_hi_show(mddev_t *mddev, char *page)
2399 {
2400 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
2401 }
2402 
2403 static ssize_t
2404 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
2405 {
2406 	char *e;
2407 	unsigned long long new = simple_strtoull(buf, &e, 10);
2408 
2409 	if (mddev->pers->quiesce == NULL)
2410 		return -EINVAL;
2411 	if (buf == e || (*e && *e != '\n'))
2412 		return -EINVAL;
2413 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
2414 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
2415 		mddev->suspend_hi = new;
2416 		mddev->pers->quiesce(mddev, 1);
2417 		mddev->pers->quiesce(mddev, 0);
2418 		return len;
2419 	} else
2420 		return -EINVAL;
2421 }
2422 static struct md_sysfs_entry md_suspend_hi =
2423 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
2424 
2425 
2426 static struct attribute *md_default_attrs[] = {
2427 	&md_level.attr,
2428 	&md_raid_disks.attr,
2429 	&md_chunk_size.attr,
2430 	&md_size.attr,
2431 	&md_metadata.attr,
2432 	&md_new_device.attr,
2433 	NULL,
2434 };
2435 
2436 static struct attribute *md_redundancy_attrs[] = {
2437 	&md_scan_mode.attr,
2438 	&md_mismatches.attr,
2439 	&md_sync_min.attr,
2440 	&md_sync_max.attr,
2441 	&md_sync_speed.attr,
2442 	&md_sync_completed.attr,
2443 	&md_suspend_lo.attr,
2444 	&md_suspend_hi.attr,
2445 	NULL,
2446 };
2447 static struct attribute_group md_redundancy_group = {
2448 	.name = NULL,
2449 	.attrs = md_redundancy_attrs,
2450 };
2451 
2452 
2453 static ssize_t
2454 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2455 {
2456 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
2457 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
2458 	ssize_t rv;
2459 
2460 	if (!entry->show)
2461 		return -EIO;
2462 	mddev_lock(mddev);
2463 	rv = entry->show(mddev, page);
2464 	mddev_unlock(mddev);
2465 	return rv;
2466 }
2467 
2468 static ssize_t
2469 md_attr_store(struct kobject *kobj, struct attribute *attr,
2470 	      const char *page, size_t length)
2471 {
2472 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
2473 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
2474 	ssize_t rv;
2475 
2476 	if (!entry->store)
2477 		return -EIO;
2478 	mddev_lock(mddev);
2479 	rv = entry->store(mddev, page, length);
2480 	mddev_unlock(mddev);
2481 	return rv;
2482 }
2483 
2484 static void md_free(struct kobject *ko)
2485 {
2486 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
2487 	kfree(mddev);
2488 }
2489 
2490 static struct sysfs_ops md_sysfs_ops = {
2491 	.show	= md_attr_show,
2492 	.store	= md_attr_store,
2493 };
2494 static struct kobj_type md_ktype = {
2495 	.release	= md_free,
2496 	.sysfs_ops	= &md_sysfs_ops,
2497 	.default_attrs	= md_default_attrs,
2498 };
2499 
2500 int mdp_major = 0;
2501 
2502 static struct kobject *md_probe(dev_t dev, int *part, void *data)
2503 {
2504 	static DEFINE_MUTEX(disks_mutex);
2505 	mddev_t *mddev = mddev_find(dev);
2506 	struct gendisk *disk;
2507 	int partitioned = (MAJOR(dev) != MD_MAJOR);
2508 	int shift = partitioned ? MdpMinorShift : 0;
2509 	int unit = MINOR(dev) >> shift;
2510 
2511 	if (!mddev)
2512 		return NULL;
2513 
2514 	mutex_lock(&disks_mutex);
2515 	if (mddev->gendisk) {
2516 		mutex_unlock(&disks_mutex);
2517 		mddev_put(mddev);
2518 		return NULL;
2519 	}
2520 	disk = alloc_disk(1 << shift);
2521 	if (!disk) {
2522 		mutex_unlock(&disks_mutex);
2523 		mddev_put(mddev);
2524 		return NULL;
2525 	}
2526 	disk->major = MAJOR(dev);
2527 	disk->first_minor = unit << shift;
2528 	if (partitioned) {
2529 		sprintf(disk->disk_name, "md_d%d", unit);
2530 		sprintf(disk->devfs_name, "md/d%d", unit);
2531 	} else {
2532 		sprintf(disk->disk_name, "md%d", unit);
2533 		sprintf(disk->devfs_name, "md/%d", unit);
2534 	}
2535 	disk->fops = &md_fops;
2536 	disk->private_data = mddev;
2537 	disk->queue = mddev->queue;
2538 	add_disk(disk);
2539 	mddev->gendisk = disk;
2540 	mutex_unlock(&disks_mutex);
2541 	mddev->kobj.parent = &disk->kobj;
2542 	mddev->kobj.k_name = NULL;
2543 	snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
2544 	mddev->kobj.ktype = &md_ktype;
2545 	kobject_register(&mddev->kobj);
2546 	return NULL;
2547 }
2548 
2549 void md_wakeup_thread(mdk_thread_t *thread);
2550 
2551 static void md_safemode_timeout(unsigned long data)
2552 {
2553 	mddev_t *mddev = (mddev_t *) data;
2554 
2555 	mddev->safemode = 1;
2556 	md_wakeup_thread(mddev->thread);
2557 }
2558 
2559 static int start_dirty_degraded;
2560 
2561 static int do_md_run(mddev_t * mddev)
2562 {
2563 	int err;
2564 	int chunk_size;
2565 	struct list_head *tmp;
2566 	mdk_rdev_t *rdev;
2567 	struct gendisk *disk;
2568 	struct mdk_personality *pers;
2569 	char b[BDEVNAME_SIZE];
2570 
2571 	if (list_empty(&mddev->disks))
2572 		/* cannot run an array with no devices.. */
2573 		return -EINVAL;
2574 
2575 	if (mddev->pers)
2576 		return -EBUSY;
2577 
2578 	/*
2579 	 * Analyze all RAID superblock(s)
2580 	 */
2581 	if (!mddev->raid_disks)
2582 		analyze_sbs(mddev);
2583 
2584 	chunk_size = mddev->chunk_size;
2585 
2586 	if (chunk_size) {
2587 		if (chunk_size > MAX_CHUNK_SIZE) {
2588 			printk(KERN_ERR "too big chunk_size: %d > %d\n",
2589 				chunk_size, MAX_CHUNK_SIZE);
2590 			return -EINVAL;
2591 		}
2592 		/*
2593 		 * chunk-size has to be a power of 2 and multiples of PAGE_SIZE
2594 		 */
2595 		if ( (1 << ffz(~chunk_size)) != chunk_size) {
2596 			printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
2597 			return -EINVAL;
2598 		}
2599 		if (chunk_size < PAGE_SIZE) {
2600 			printk(KERN_ERR "too small chunk_size: %d < %ld\n",
2601 				chunk_size, PAGE_SIZE);
2602 			return -EINVAL;
2603 		}
2604 
2605 		/* devices must have minimum size of one chunk */
2606 		ITERATE_RDEV(mddev,rdev,tmp) {
2607 			if (test_bit(Faulty, &rdev->flags))
2608 				continue;
2609 			if (rdev->size < chunk_size / 1024) {
2610 				printk(KERN_WARNING
2611 					"md: Dev %s smaller than chunk_size:"
2612 					" %lluk < %dk\n",
2613 					bdevname(rdev->bdev,b),
2614 					(unsigned long long)rdev->size,
2615 					chunk_size / 1024);
2616 				return -EINVAL;
2617 			}
2618 		}
2619 	}
2620 
2621 #ifdef CONFIG_KMOD
2622 	if (mddev->level != LEVEL_NONE)
2623 		request_module("md-level-%d", mddev->level);
2624 	else if (mddev->clevel[0])
2625 		request_module("md-%s", mddev->clevel);
2626 #endif
2627 
2628 	/*
2629 	 * Drop all container device buffers, from now on
2630 	 * the only valid external interface is through the md
2631 	 * device.
2632 	 * Also find largest hardsector size
2633 	 */
2634 	ITERATE_RDEV(mddev,rdev,tmp) {
2635 		if (test_bit(Faulty, &rdev->flags))
2636 			continue;
2637 		sync_blockdev(rdev->bdev);
2638 		invalidate_bdev(rdev->bdev, 0);
2639 	}
2640 
2641 	md_probe(mddev->unit, NULL, NULL);
2642 	disk = mddev->gendisk;
2643 	if (!disk)
2644 		return -ENOMEM;
2645 
2646 	spin_lock(&pers_lock);
2647 	pers = find_pers(mddev->level, mddev->clevel);
2648 	if (!pers || !try_module_get(pers->owner)) {
2649 		spin_unlock(&pers_lock);
2650 		if (mddev->level != LEVEL_NONE)
2651 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
2652 			       mddev->level);
2653 		else
2654 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
2655 			       mddev->clevel);
2656 		return -EINVAL;
2657 	}
2658 	mddev->pers = pers;
2659 	spin_unlock(&pers_lock);
2660 	mddev->level = pers->level;
2661 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
2662 
2663 	if (mddev->reshape_position != MaxSector &&
2664 	    pers->start_reshape == NULL) {
2665 		/* This personality cannot handle reshaping... */
2666 		mddev->pers = NULL;
2667 		module_put(pers->owner);
2668 		return -EINVAL;
2669 	}
2670 
2671 	mddev->recovery = 0;
2672 	mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
2673 	mddev->barriers_work = 1;
2674 	mddev->ok_start_degraded = start_dirty_degraded;
2675 
2676 	if (start_readonly)
2677 		mddev->ro = 2; /* read-only, but switch on first write */
2678 
2679 	err = mddev->pers->run(mddev);
2680 	if (!err && mddev->pers->sync_request) {
2681 		err = bitmap_create(mddev);
2682 		if (err) {
2683 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
2684 			       mdname(mddev), err);
2685 			mddev->pers->stop(mddev);
2686 		}
2687 	}
2688 	if (err) {
2689 		printk(KERN_ERR "md: pers->run() failed ...\n");
2690 		module_put(mddev->pers->owner);
2691 		mddev->pers = NULL;
2692 		bitmap_destroy(mddev);
2693 		return err;
2694 	}
2695 	if (mddev->pers->sync_request)
2696 		sysfs_create_group(&mddev->kobj, &md_redundancy_group);
2697 	else if (mddev->ro == 2) /* auto-readonly not meaningful */
2698 		mddev->ro = 0;
2699 
2700  	atomic_set(&mddev->writes_pending,0);
2701 	mddev->safemode = 0;
2702 	mddev->safemode_timer.function = md_safemode_timeout;
2703 	mddev->safemode_timer.data = (unsigned long) mddev;
2704 	mddev->safemode_delay = (20 * HZ)/1000 +1; /* 20 msec delay */
2705 	mddev->in_sync = 1;
2706 
2707 	ITERATE_RDEV(mddev,rdev,tmp)
2708 		if (rdev->raid_disk >= 0) {
2709 			char nm[20];
2710 			sprintf(nm, "rd%d", rdev->raid_disk);
2711 			sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
2712 		}
2713 
2714 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2715 	md_wakeup_thread(mddev->thread);
2716 
2717 	if (mddev->sb_dirty)
2718 		md_update_sb(mddev);
2719 
2720 	set_capacity(disk, mddev->array_size<<1);
2721 
2722 	/* If we call blk_queue_make_request here, it will
2723 	 * re-initialise max_sectors etc which may have been
2724 	 * refined inside -> run.  So just set the bits we need to set.
2725 	 * Most initialisation happended when we called
2726 	 * blk_queue_make_request(..., md_fail_request)
2727 	 * earlier.
2728 	 */
2729 	mddev->queue->queuedata = mddev;
2730 	mddev->queue->make_request_fn = mddev->pers->make_request;
2731 
2732 	mddev->changed = 1;
2733 	md_new_event(mddev);
2734 	return 0;
2735 }
2736 
2737 static int restart_array(mddev_t *mddev)
2738 {
2739 	struct gendisk *disk = mddev->gendisk;
2740 	int err;
2741 
2742 	/*
2743 	 * Complain if it has no devices
2744 	 */
2745 	err = -ENXIO;
2746 	if (list_empty(&mddev->disks))
2747 		goto out;
2748 
2749 	if (mddev->pers) {
2750 		err = -EBUSY;
2751 		if (!mddev->ro)
2752 			goto out;
2753 
2754 		mddev->safemode = 0;
2755 		mddev->ro = 0;
2756 		set_disk_ro(disk, 0);
2757 
2758 		printk(KERN_INFO "md: %s switched to read-write mode.\n",
2759 			mdname(mddev));
2760 		/*
2761 		 * Kick recovery or resync if necessary
2762 		 */
2763 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2764 		md_wakeup_thread(mddev->thread);
2765 		err = 0;
2766 	} else {
2767 		printk(KERN_ERR "md: %s has no personality assigned.\n",
2768 			mdname(mddev));
2769 		err = -EINVAL;
2770 	}
2771 
2772 out:
2773 	return err;
2774 }
2775 
2776 static int do_md_stop(mddev_t * mddev, int ro)
2777 {
2778 	int err = 0;
2779 	struct gendisk *disk = mddev->gendisk;
2780 
2781 	if (mddev->pers) {
2782 		if (atomic_read(&mddev->active)>2) {
2783 			printk("md: %s still in use.\n",mdname(mddev));
2784 			return -EBUSY;
2785 		}
2786 
2787 		if (mddev->sync_thread) {
2788 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2789 			md_unregister_thread(mddev->sync_thread);
2790 			mddev->sync_thread = NULL;
2791 		}
2792 
2793 		del_timer_sync(&mddev->safemode_timer);
2794 
2795 		invalidate_partition(disk, 0);
2796 
2797 		if (ro) {
2798 			err  = -ENXIO;
2799 			if (mddev->ro==1)
2800 				goto out;
2801 			mddev->ro = 1;
2802 		} else {
2803 			bitmap_flush(mddev);
2804 			md_super_wait(mddev);
2805 			if (mddev->ro)
2806 				set_disk_ro(disk, 0);
2807 			blk_queue_make_request(mddev->queue, md_fail_request);
2808 			mddev->pers->stop(mddev);
2809 			if (mddev->pers->sync_request)
2810 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
2811 
2812 			module_put(mddev->pers->owner);
2813 			mddev->pers = NULL;
2814 			if (mddev->ro)
2815 				mddev->ro = 0;
2816 		}
2817 		if (!mddev->in_sync) {
2818 			/* mark array as shutdown cleanly */
2819 			mddev->in_sync = 1;
2820 			md_update_sb(mddev);
2821 		}
2822 		if (ro)
2823 			set_disk_ro(disk, 1);
2824 	}
2825 
2826 	/*
2827 	 * Free resources if final stop
2828 	 */
2829 	if (!ro) {
2830 		mdk_rdev_t *rdev;
2831 		struct list_head *tmp;
2832 		struct gendisk *disk;
2833 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
2834 
2835 		bitmap_destroy(mddev);
2836 		if (mddev->bitmap_file) {
2837 			atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
2838 			fput(mddev->bitmap_file);
2839 			mddev->bitmap_file = NULL;
2840 		}
2841 		mddev->bitmap_offset = 0;
2842 
2843 		ITERATE_RDEV(mddev,rdev,tmp)
2844 			if (rdev->raid_disk >= 0) {
2845 				char nm[20];
2846 				sprintf(nm, "rd%d", rdev->raid_disk);
2847 				sysfs_remove_link(&mddev->kobj, nm);
2848 			}
2849 
2850 		export_array(mddev);
2851 
2852 		mddev->array_size = 0;
2853 		disk = mddev->gendisk;
2854 		if (disk)
2855 			set_capacity(disk, 0);
2856 		mddev->changed = 1;
2857 	} else
2858 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
2859 			mdname(mddev));
2860 	err = 0;
2861 	md_new_event(mddev);
2862 out:
2863 	return err;
2864 }
2865 
2866 static void autorun_array(mddev_t *mddev)
2867 {
2868 	mdk_rdev_t *rdev;
2869 	struct list_head *tmp;
2870 	int err;
2871 
2872 	if (list_empty(&mddev->disks))
2873 		return;
2874 
2875 	printk(KERN_INFO "md: running: ");
2876 
2877 	ITERATE_RDEV(mddev,rdev,tmp) {
2878 		char b[BDEVNAME_SIZE];
2879 		printk("<%s>", bdevname(rdev->bdev,b));
2880 	}
2881 	printk("\n");
2882 
2883 	err = do_md_run (mddev);
2884 	if (err) {
2885 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
2886 		do_md_stop (mddev, 0);
2887 	}
2888 }
2889 
2890 /*
2891  * lets try to run arrays based on all disks that have arrived
2892  * until now. (those are in pending_raid_disks)
2893  *
2894  * the method: pick the first pending disk, collect all disks with
2895  * the same UUID, remove all from the pending list and put them into
2896  * the 'same_array' list. Then order this list based on superblock
2897  * update time (freshest comes first), kick out 'old' disks and
2898  * compare superblocks. If everything's fine then run it.
2899  *
2900  * If "unit" is allocated, then bump its reference count
2901  */
2902 static void autorun_devices(int part)
2903 {
2904 	struct list_head *tmp;
2905 	mdk_rdev_t *rdev0, *rdev;
2906 	mddev_t *mddev;
2907 	char b[BDEVNAME_SIZE];
2908 
2909 	printk(KERN_INFO "md: autorun ...\n");
2910 	while (!list_empty(&pending_raid_disks)) {
2911 		dev_t dev;
2912 		LIST_HEAD(candidates);
2913 		rdev0 = list_entry(pending_raid_disks.next,
2914 					 mdk_rdev_t, same_set);
2915 
2916 		printk(KERN_INFO "md: considering %s ...\n",
2917 			bdevname(rdev0->bdev,b));
2918 		INIT_LIST_HEAD(&candidates);
2919 		ITERATE_RDEV_PENDING(rdev,tmp)
2920 			if (super_90_load(rdev, rdev0, 0) >= 0) {
2921 				printk(KERN_INFO "md:  adding %s ...\n",
2922 					bdevname(rdev->bdev,b));
2923 				list_move(&rdev->same_set, &candidates);
2924 			}
2925 		/*
2926 		 * now we have a set of devices, with all of them having
2927 		 * mostly sane superblocks. It's time to allocate the
2928 		 * mddev.
2929 		 */
2930 		if (rdev0->preferred_minor < 0 || rdev0->preferred_minor >= MAX_MD_DEVS) {
2931 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
2932 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
2933 			break;
2934 		}
2935 		if (part)
2936 			dev = MKDEV(mdp_major,
2937 				    rdev0->preferred_minor << MdpMinorShift);
2938 		else
2939 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
2940 
2941 		md_probe(dev, NULL, NULL);
2942 		mddev = mddev_find(dev);
2943 		if (!mddev) {
2944 			printk(KERN_ERR
2945 				"md: cannot allocate memory for md drive.\n");
2946 			break;
2947 		}
2948 		if (mddev_lock(mddev))
2949 			printk(KERN_WARNING "md: %s locked, cannot run\n",
2950 			       mdname(mddev));
2951 		else if (mddev->raid_disks || mddev->major_version
2952 			 || !list_empty(&mddev->disks)) {
2953 			printk(KERN_WARNING
2954 				"md: %s already running, cannot run %s\n",
2955 				mdname(mddev), bdevname(rdev0->bdev,b));
2956 			mddev_unlock(mddev);
2957 		} else {
2958 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
2959 			ITERATE_RDEV_GENERIC(candidates,rdev,tmp) {
2960 				list_del_init(&rdev->same_set);
2961 				if (bind_rdev_to_array(rdev, mddev))
2962 					export_rdev(rdev);
2963 			}
2964 			autorun_array(mddev);
2965 			mddev_unlock(mddev);
2966 		}
2967 		/* on success, candidates will be empty, on error
2968 		 * it won't...
2969 		 */
2970 		ITERATE_RDEV_GENERIC(candidates,rdev,tmp)
2971 			export_rdev(rdev);
2972 		mddev_put(mddev);
2973 	}
2974 	printk(KERN_INFO "md: ... autorun DONE.\n");
2975 }
2976 
2977 /*
2978  * import RAID devices based on one partition
2979  * if possible, the array gets run as well.
2980  */
2981 
2982 static int autostart_array(dev_t startdev)
2983 {
2984 	char b[BDEVNAME_SIZE];
2985 	int err = -EINVAL, i;
2986 	mdp_super_t *sb = NULL;
2987 	mdk_rdev_t *start_rdev = NULL, *rdev;
2988 
2989 	start_rdev = md_import_device(startdev, 0, 0);
2990 	if (IS_ERR(start_rdev))
2991 		return err;
2992 
2993 
2994 	/* NOTE: this can only work for 0.90.0 superblocks */
2995 	sb = (mdp_super_t*)page_address(start_rdev->sb_page);
2996 	if (sb->major_version != 0 ||
2997 	    sb->minor_version != 90 ) {
2998 		printk(KERN_WARNING "md: can only autostart 0.90.0 arrays\n");
2999 		export_rdev(start_rdev);
3000 		return err;
3001 	}
3002 
3003 	if (test_bit(Faulty, &start_rdev->flags)) {
3004 		printk(KERN_WARNING
3005 			"md: can not autostart based on faulty %s!\n",
3006 			bdevname(start_rdev->bdev,b));
3007 		export_rdev(start_rdev);
3008 		return err;
3009 	}
3010 	list_add(&start_rdev->same_set, &pending_raid_disks);
3011 
3012 	for (i = 0; i < MD_SB_DISKS; i++) {
3013 		mdp_disk_t *desc = sb->disks + i;
3014 		dev_t dev = MKDEV(desc->major, desc->minor);
3015 
3016 		if (!dev)
3017 			continue;
3018 		if (dev == startdev)
3019 			continue;
3020 		if (MAJOR(dev) != desc->major || MINOR(dev) != desc->minor)
3021 			continue;
3022 		rdev = md_import_device(dev, 0, 0);
3023 		if (IS_ERR(rdev))
3024 			continue;
3025 
3026 		list_add(&rdev->same_set, &pending_raid_disks);
3027 	}
3028 
3029 	/*
3030 	 * possibly return codes
3031 	 */
3032 	autorun_devices(0);
3033 	return 0;
3034 
3035 }
3036 
3037 
3038 static int get_version(void __user * arg)
3039 {
3040 	mdu_version_t ver;
3041 
3042 	ver.major = MD_MAJOR_VERSION;
3043 	ver.minor = MD_MINOR_VERSION;
3044 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
3045 
3046 	if (copy_to_user(arg, &ver, sizeof(ver)))
3047 		return -EFAULT;
3048 
3049 	return 0;
3050 }
3051 
3052 static int get_array_info(mddev_t * mddev, void __user * arg)
3053 {
3054 	mdu_array_info_t info;
3055 	int nr,working,active,failed,spare;
3056 	mdk_rdev_t *rdev;
3057 	struct list_head *tmp;
3058 
3059 	nr=working=active=failed=spare=0;
3060 	ITERATE_RDEV(mddev,rdev,tmp) {
3061 		nr++;
3062 		if (test_bit(Faulty, &rdev->flags))
3063 			failed++;
3064 		else {
3065 			working++;
3066 			if (test_bit(In_sync, &rdev->flags))
3067 				active++;
3068 			else
3069 				spare++;
3070 		}
3071 	}
3072 
3073 	info.major_version = mddev->major_version;
3074 	info.minor_version = mddev->minor_version;
3075 	info.patch_version = MD_PATCHLEVEL_VERSION;
3076 	info.ctime         = mddev->ctime;
3077 	info.level         = mddev->level;
3078 	info.size          = mddev->size;
3079 	if (info.size != mddev->size) /* overflow */
3080 		info.size = -1;
3081 	info.nr_disks      = nr;
3082 	info.raid_disks    = mddev->raid_disks;
3083 	info.md_minor      = mddev->md_minor;
3084 	info.not_persistent= !mddev->persistent;
3085 
3086 	info.utime         = mddev->utime;
3087 	info.state         = 0;
3088 	if (mddev->in_sync)
3089 		info.state = (1<<MD_SB_CLEAN);
3090 	if (mddev->bitmap && mddev->bitmap_offset)
3091 		info.state = (1<<MD_SB_BITMAP_PRESENT);
3092 	info.active_disks  = active;
3093 	info.working_disks = working;
3094 	info.failed_disks  = failed;
3095 	info.spare_disks   = spare;
3096 
3097 	info.layout        = mddev->layout;
3098 	info.chunk_size    = mddev->chunk_size;
3099 
3100 	if (copy_to_user(arg, &info, sizeof(info)))
3101 		return -EFAULT;
3102 
3103 	return 0;
3104 }
3105 
3106 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
3107 {
3108 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
3109 	char *ptr, *buf = NULL;
3110 	int err = -ENOMEM;
3111 
3112 	file = kmalloc(sizeof(*file), GFP_KERNEL);
3113 	if (!file)
3114 		goto out;
3115 
3116 	/* bitmap disabled, zero the first byte and copy out */
3117 	if (!mddev->bitmap || !mddev->bitmap->file) {
3118 		file->pathname[0] = '\0';
3119 		goto copy_out;
3120 	}
3121 
3122 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
3123 	if (!buf)
3124 		goto out;
3125 
3126 	ptr = file_path(mddev->bitmap->file, buf, sizeof(file->pathname));
3127 	if (!ptr)
3128 		goto out;
3129 
3130 	strcpy(file->pathname, ptr);
3131 
3132 copy_out:
3133 	err = 0;
3134 	if (copy_to_user(arg, file, sizeof(*file)))
3135 		err = -EFAULT;
3136 out:
3137 	kfree(buf);
3138 	kfree(file);
3139 	return err;
3140 }
3141 
3142 static int get_disk_info(mddev_t * mddev, void __user * arg)
3143 {
3144 	mdu_disk_info_t info;
3145 	unsigned int nr;
3146 	mdk_rdev_t *rdev;
3147 
3148 	if (copy_from_user(&info, arg, sizeof(info)))
3149 		return -EFAULT;
3150 
3151 	nr = info.number;
3152 
3153 	rdev = find_rdev_nr(mddev, nr);
3154 	if (rdev) {
3155 		info.major = MAJOR(rdev->bdev->bd_dev);
3156 		info.minor = MINOR(rdev->bdev->bd_dev);
3157 		info.raid_disk = rdev->raid_disk;
3158 		info.state = 0;
3159 		if (test_bit(Faulty, &rdev->flags))
3160 			info.state |= (1<<MD_DISK_FAULTY);
3161 		else if (test_bit(In_sync, &rdev->flags)) {
3162 			info.state |= (1<<MD_DISK_ACTIVE);
3163 			info.state |= (1<<MD_DISK_SYNC);
3164 		}
3165 		if (test_bit(WriteMostly, &rdev->flags))
3166 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
3167 	} else {
3168 		info.major = info.minor = 0;
3169 		info.raid_disk = -1;
3170 		info.state = (1<<MD_DISK_REMOVED);
3171 	}
3172 
3173 	if (copy_to_user(arg, &info, sizeof(info)))
3174 		return -EFAULT;
3175 
3176 	return 0;
3177 }
3178 
3179 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
3180 {
3181 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
3182 	mdk_rdev_t *rdev;
3183 	dev_t dev = MKDEV(info->major,info->minor);
3184 
3185 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
3186 		return -EOVERFLOW;
3187 
3188 	if (!mddev->raid_disks) {
3189 		int err;
3190 		/* expecting a device which has a superblock */
3191 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
3192 		if (IS_ERR(rdev)) {
3193 			printk(KERN_WARNING
3194 				"md: md_import_device returned %ld\n",
3195 				PTR_ERR(rdev));
3196 			return PTR_ERR(rdev);
3197 		}
3198 		if (!list_empty(&mddev->disks)) {
3199 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3200 							mdk_rdev_t, same_set);
3201 			int err = super_types[mddev->major_version]
3202 				.load_super(rdev, rdev0, mddev->minor_version);
3203 			if (err < 0) {
3204 				printk(KERN_WARNING
3205 					"md: %s has different UUID to %s\n",
3206 					bdevname(rdev->bdev,b),
3207 					bdevname(rdev0->bdev,b2));
3208 				export_rdev(rdev);
3209 				return -EINVAL;
3210 			}
3211 		}
3212 		err = bind_rdev_to_array(rdev, mddev);
3213 		if (err)
3214 			export_rdev(rdev);
3215 		return err;
3216 	}
3217 
3218 	/*
3219 	 * add_new_disk can be used once the array is assembled
3220 	 * to add "hot spares".  They must already have a superblock
3221 	 * written
3222 	 */
3223 	if (mddev->pers) {
3224 		int err;
3225 		if (!mddev->pers->hot_add_disk) {
3226 			printk(KERN_WARNING
3227 				"%s: personality does not support diskops!\n",
3228 			       mdname(mddev));
3229 			return -EINVAL;
3230 		}
3231 		if (mddev->persistent)
3232 			rdev = md_import_device(dev, mddev->major_version,
3233 						mddev->minor_version);
3234 		else
3235 			rdev = md_import_device(dev, -1, -1);
3236 		if (IS_ERR(rdev)) {
3237 			printk(KERN_WARNING
3238 				"md: md_import_device returned %ld\n",
3239 				PTR_ERR(rdev));
3240 			return PTR_ERR(rdev);
3241 		}
3242 		/* set save_raid_disk if appropriate */
3243 		if (!mddev->persistent) {
3244 			if (info->state & (1<<MD_DISK_SYNC)  &&
3245 			    info->raid_disk < mddev->raid_disks)
3246 				rdev->raid_disk = info->raid_disk;
3247 			else
3248 				rdev->raid_disk = -1;
3249 		} else
3250 			super_types[mddev->major_version].
3251 				validate_super(mddev, rdev);
3252 		rdev->saved_raid_disk = rdev->raid_disk;
3253 
3254 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
3255 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3256 			set_bit(WriteMostly, &rdev->flags);
3257 
3258 		rdev->raid_disk = -1;
3259 		err = bind_rdev_to_array(rdev, mddev);
3260 		if (err)
3261 			export_rdev(rdev);
3262 
3263 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3264 		md_wakeup_thread(mddev->thread);
3265 		return err;
3266 	}
3267 
3268 	/* otherwise, add_new_disk is only allowed
3269 	 * for major_version==0 superblocks
3270 	 */
3271 	if (mddev->major_version != 0) {
3272 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
3273 		       mdname(mddev));
3274 		return -EINVAL;
3275 	}
3276 
3277 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
3278 		int err;
3279 		rdev = md_import_device (dev, -1, 0);
3280 		if (IS_ERR(rdev)) {
3281 			printk(KERN_WARNING
3282 				"md: error, md_import_device() returned %ld\n",
3283 				PTR_ERR(rdev));
3284 			return PTR_ERR(rdev);
3285 		}
3286 		rdev->desc_nr = info->number;
3287 		if (info->raid_disk < mddev->raid_disks)
3288 			rdev->raid_disk = info->raid_disk;
3289 		else
3290 			rdev->raid_disk = -1;
3291 
3292 		rdev->flags = 0;
3293 
3294 		if (rdev->raid_disk < mddev->raid_disks)
3295 			if (info->state & (1<<MD_DISK_SYNC))
3296 				set_bit(In_sync, &rdev->flags);
3297 
3298 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
3299 			set_bit(WriteMostly, &rdev->flags);
3300 
3301 		if (!mddev->persistent) {
3302 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
3303 			rdev->sb_offset = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
3304 		} else
3305 			rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
3306 		rdev->size = calc_dev_size(rdev, mddev->chunk_size);
3307 
3308 		err = bind_rdev_to_array(rdev, mddev);
3309 		if (err) {
3310 			export_rdev(rdev);
3311 			return err;
3312 		}
3313 	}
3314 
3315 	return 0;
3316 }
3317 
3318 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
3319 {
3320 	char b[BDEVNAME_SIZE];
3321 	mdk_rdev_t *rdev;
3322 
3323 	if (!mddev->pers)
3324 		return -ENODEV;
3325 
3326 	rdev = find_rdev(mddev, dev);
3327 	if (!rdev)
3328 		return -ENXIO;
3329 
3330 	if (rdev->raid_disk >= 0)
3331 		goto busy;
3332 
3333 	kick_rdev_from_array(rdev);
3334 	md_update_sb(mddev);
3335 	md_new_event(mddev);
3336 
3337 	return 0;
3338 busy:
3339 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ... \n",
3340 		bdevname(rdev->bdev,b), mdname(mddev));
3341 	return -EBUSY;
3342 }
3343 
3344 static int hot_add_disk(mddev_t * mddev, dev_t dev)
3345 {
3346 	char b[BDEVNAME_SIZE];
3347 	int err;
3348 	unsigned int size;
3349 	mdk_rdev_t *rdev;
3350 
3351 	if (!mddev->pers)
3352 		return -ENODEV;
3353 
3354 	if (mddev->major_version != 0) {
3355 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
3356 			" version-0 superblocks.\n",
3357 			mdname(mddev));
3358 		return -EINVAL;
3359 	}
3360 	if (!mddev->pers->hot_add_disk) {
3361 		printk(KERN_WARNING
3362 			"%s: personality does not support diskops!\n",
3363 			mdname(mddev));
3364 		return -EINVAL;
3365 	}
3366 
3367 	rdev = md_import_device (dev, -1, 0);
3368 	if (IS_ERR(rdev)) {
3369 		printk(KERN_WARNING
3370 			"md: error, md_import_device() returned %ld\n",
3371 			PTR_ERR(rdev));
3372 		return -EINVAL;
3373 	}
3374 
3375 	if (mddev->persistent)
3376 		rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
3377 	else
3378 		rdev->sb_offset =
3379 			rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
3380 
3381 	size = calc_dev_size(rdev, mddev->chunk_size);
3382 	rdev->size = size;
3383 
3384 	if (test_bit(Faulty, &rdev->flags)) {
3385 		printk(KERN_WARNING
3386 			"md: can not hot-add faulty %s disk to %s!\n",
3387 			bdevname(rdev->bdev,b), mdname(mddev));
3388 		err = -EINVAL;
3389 		goto abort_export;
3390 	}
3391 	clear_bit(In_sync, &rdev->flags);
3392 	rdev->desc_nr = -1;
3393 	err = bind_rdev_to_array(rdev, mddev);
3394 	if (err)
3395 		goto abort_export;
3396 
3397 	/*
3398 	 * The rest should better be atomic, we can have disk failures
3399 	 * noticed in interrupt contexts ...
3400 	 */
3401 
3402 	if (rdev->desc_nr == mddev->max_disks) {
3403 		printk(KERN_WARNING "%s: can not hot-add to full array!\n",
3404 			mdname(mddev));
3405 		err = -EBUSY;
3406 		goto abort_unbind_export;
3407 	}
3408 
3409 	rdev->raid_disk = -1;
3410 
3411 	md_update_sb(mddev);
3412 
3413 	/*
3414 	 * Kick recovery, maybe this spare has to be added to the
3415 	 * array immediately.
3416 	 */
3417 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3418 	md_wakeup_thread(mddev->thread);
3419 	md_new_event(mddev);
3420 	return 0;
3421 
3422 abort_unbind_export:
3423 	unbind_rdev_from_array(rdev);
3424 
3425 abort_export:
3426 	export_rdev(rdev);
3427 	return err;
3428 }
3429 
3430 /* similar to deny_write_access, but accounts for our holding a reference
3431  * to the file ourselves */
3432 static int deny_bitmap_write_access(struct file * file)
3433 {
3434 	struct inode *inode = file->f_mapping->host;
3435 
3436 	spin_lock(&inode->i_lock);
3437 	if (atomic_read(&inode->i_writecount) > 1) {
3438 		spin_unlock(&inode->i_lock);
3439 		return -ETXTBSY;
3440 	}
3441 	atomic_set(&inode->i_writecount, -1);
3442 	spin_unlock(&inode->i_lock);
3443 
3444 	return 0;
3445 }
3446 
3447 static int set_bitmap_file(mddev_t *mddev, int fd)
3448 {
3449 	int err;
3450 
3451 	if (mddev->pers) {
3452 		if (!mddev->pers->quiesce)
3453 			return -EBUSY;
3454 		if (mddev->recovery || mddev->sync_thread)
3455 			return -EBUSY;
3456 		/* we should be able to change the bitmap.. */
3457 	}
3458 
3459 
3460 	if (fd >= 0) {
3461 		if (mddev->bitmap)
3462 			return -EEXIST; /* cannot add when bitmap is present */
3463 		mddev->bitmap_file = fget(fd);
3464 
3465 		if (mddev->bitmap_file == NULL) {
3466 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
3467 			       mdname(mddev));
3468 			return -EBADF;
3469 		}
3470 
3471 		err = deny_bitmap_write_access(mddev->bitmap_file);
3472 		if (err) {
3473 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
3474 			       mdname(mddev));
3475 			fput(mddev->bitmap_file);
3476 			mddev->bitmap_file = NULL;
3477 			return err;
3478 		}
3479 		mddev->bitmap_offset = 0; /* file overrides offset */
3480 	} else if (mddev->bitmap == NULL)
3481 		return -ENOENT; /* cannot remove what isn't there */
3482 	err = 0;
3483 	if (mddev->pers) {
3484 		mddev->pers->quiesce(mddev, 1);
3485 		if (fd >= 0)
3486 			err = bitmap_create(mddev);
3487 		if (fd < 0 || err)
3488 			bitmap_destroy(mddev);
3489 		mddev->pers->quiesce(mddev, 0);
3490 	} else if (fd < 0) {
3491 		if (mddev->bitmap_file)
3492 			fput(mddev->bitmap_file);
3493 		mddev->bitmap_file = NULL;
3494 	}
3495 
3496 	return err;
3497 }
3498 
3499 /*
3500  * set_array_info is used two different ways
3501  * The original usage is when creating a new array.
3502  * In this usage, raid_disks is > 0 and it together with
3503  *  level, size, not_persistent,layout,chunksize determine the
3504  *  shape of the array.
3505  *  This will always create an array with a type-0.90.0 superblock.
3506  * The newer usage is when assembling an array.
3507  *  In this case raid_disks will be 0, and the major_version field is
3508  *  use to determine which style super-blocks are to be found on the devices.
3509  *  The minor and patch _version numbers are also kept incase the
3510  *  super_block handler wishes to interpret them.
3511  */
3512 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
3513 {
3514 
3515 	if (info->raid_disks == 0) {
3516 		/* just setting version number for superblock loading */
3517 		if (info->major_version < 0 ||
3518 		    info->major_version >= sizeof(super_types)/sizeof(super_types[0]) ||
3519 		    super_types[info->major_version].name == NULL) {
3520 			/* maybe try to auto-load a module? */
3521 			printk(KERN_INFO
3522 				"md: superblock version %d not known\n",
3523 				info->major_version);
3524 			return -EINVAL;
3525 		}
3526 		mddev->major_version = info->major_version;
3527 		mddev->minor_version = info->minor_version;
3528 		mddev->patch_version = info->patch_version;
3529 		return 0;
3530 	}
3531 	mddev->major_version = MD_MAJOR_VERSION;
3532 	mddev->minor_version = MD_MINOR_VERSION;
3533 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
3534 	mddev->ctime         = get_seconds();
3535 
3536 	mddev->level         = info->level;
3537 	mddev->clevel[0]     = 0;
3538 	mddev->size          = info->size;
3539 	mddev->raid_disks    = info->raid_disks;
3540 	/* don't set md_minor, it is determined by which /dev/md* was
3541 	 * openned
3542 	 */
3543 	if (info->state & (1<<MD_SB_CLEAN))
3544 		mddev->recovery_cp = MaxSector;
3545 	else
3546 		mddev->recovery_cp = 0;
3547 	mddev->persistent    = ! info->not_persistent;
3548 
3549 	mddev->layout        = info->layout;
3550 	mddev->chunk_size    = info->chunk_size;
3551 
3552 	mddev->max_disks     = MD_SB_DISKS;
3553 
3554 	mddev->sb_dirty      = 1;
3555 
3556 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
3557 	mddev->bitmap_offset = 0;
3558 
3559 	mddev->reshape_position = MaxSector;
3560 
3561 	/*
3562 	 * Generate a 128 bit UUID
3563 	 */
3564 	get_random_bytes(mddev->uuid, 16);
3565 
3566 	mddev->new_level = mddev->level;
3567 	mddev->new_chunk = mddev->chunk_size;
3568 	mddev->new_layout = mddev->layout;
3569 	mddev->delta_disks = 0;
3570 
3571 	return 0;
3572 }
3573 
3574 static int update_size(mddev_t *mddev, unsigned long size)
3575 {
3576 	mdk_rdev_t * rdev;
3577 	int rv;
3578 	struct list_head *tmp;
3579 	int fit = (size == 0);
3580 
3581 	if (mddev->pers->resize == NULL)
3582 		return -EINVAL;
3583 	/* The "size" is the amount of each device that is used.
3584 	 * This can only make sense for arrays with redundancy.
3585 	 * linear and raid0 always use whatever space is available
3586 	 * We can only consider changing the size if no resync
3587 	 * or reconstruction is happening, and if the new size
3588 	 * is acceptable. It must fit before the sb_offset or,
3589 	 * if that is <data_offset, it must fit before the
3590 	 * size of each device.
3591 	 * If size is zero, we find the largest size that fits.
3592 	 */
3593 	if (mddev->sync_thread)
3594 		return -EBUSY;
3595 	ITERATE_RDEV(mddev,rdev,tmp) {
3596 		sector_t avail;
3597 		if (rdev->sb_offset > rdev->data_offset)
3598 			avail = (rdev->sb_offset*2) - rdev->data_offset;
3599 		else
3600 			avail = get_capacity(rdev->bdev->bd_disk)
3601 				- rdev->data_offset;
3602 		if (fit && (size == 0 || size > avail/2))
3603 			size = avail/2;
3604 		if (avail < ((sector_t)size << 1))
3605 			return -ENOSPC;
3606 	}
3607 	rv = mddev->pers->resize(mddev, (sector_t)size *2);
3608 	if (!rv) {
3609 		struct block_device *bdev;
3610 
3611 		bdev = bdget_disk(mddev->gendisk, 0);
3612 		if (bdev) {
3613 			mutex_lock(&bdev->bd_inode->i_mutex);
3614 			i_size_write(bdev->bd_inode, (loff_t)mddev->array_size << 10);
3615 			mutex_unlock(&bdev->bd_inode->i_mutex);
3616 			bdput(bdev);
3617 		}
3618 	}
3619 	return rv;
3620 }
3621 
3622 static int update_raid_disks(mddev_t *mddev, int raid_disks)
3623 {
3624 	int rv;
3625 	/* change the number of raid disks */
3626 	if (mddev->pers->check_reshape == NULL)
3627 		return -EINVAL;
3628 	if (raid_disks <= 0 ||
3629 	    raid_disks >= mddev->max_disks)
3630 		return -EINVAL;
3631 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
3632 		return -EBUSY;
3633 	mddev->delta_disks = raid_disks - mddev->raid_disks;
3634 
3635 	rv = mddev->pers->check_reshape(mddev);
3636 	return rv;
3637 }
3638 
3639 
3640 /*
3641  * update_array_info is used to change the configuration of an
3642  * on-line array.
3643  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
3644  * fields in the info are checked against the array.
3645  * Any differences that cannot be handled will cause an error.
3646  * Normally, only one change can be managed at a time.
3647  */
3648 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
3649 {
3650 	int rv = 0;
3651 	int cnt = 0;
3652 	int state = 0;
3653 
3654 	/* calculate expected state,ignoring low bits */
3655 	if (mddev->bitmap && mddev->bitmap_offset)
3656 		state |= (1 << MD_SB_BITMAP_PRESENT);
3657 
3658 	if (mddev->major_version != info->major_version ||
3659 	    mddev->minor_version != info->minor_version ||
3660 /*	    mddev->patch_version != info->patch_version || */
3661 	    mddev->ctime         != info->ctime         ||
3662 	    mddev->level         != info->level         ||
3663 /*	    mddev->layout        != info->layout        || */
3664 	    !mddev->persistent	 != info->not_persistent||
3665 	    mddev->chunk_size    != info->chunk_size    ||
3666 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
3667 	    ((state^info->state) & 0xfffffe00)
3668 		)
3669 		return -EINVAL;
3670 	/* Check there is only one change */
3671 	if (info->size >= 0 && mddev->size != info->size) cnt++;
3672 	if (mddev->raid_disks != info->raid_disks) cnt++;
3673 	if (mddev->layout != info->layout) cnt++;
3674 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
3675 	if (cnt == 0) return 0;
3676 	if (cnt > 1) return -EINVAL;
3677 
3678 	if (mddev->layout != info->layout) {
3679 		/* Change layout
3680 		 * we don't need to do anything at the md level, the
3681 		 * personality will take care of it all.
3682 		 */
3683 		if (mddev->pers->reconfig == NULL)
3684 			return -EINVAL;
3685 		else
3686 			return mddev->pers->reconfig(mddev, info->layout, -1);
3687 	}
3688 	if (info->size >= 0 && mddev->size != info->size)
3689 		rv = update_size(mddev, info->size);
3690 
3691 	if (mddev->raid_disks    != info->raid_disks)
3692 		rv = update_raid_disks(mddev, info->raid_disks);
3693 
3694 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
3695 		if (mddev->pers->quiesce == NULL)
3696 			return -EINVAL;
3697 		if (mddev->recovery || mddev->sync_thread)
3698 			return -EBUSY;
3699 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
3700 			/* add the bitmap */
3701 			if (mddev->bitmap)
3702 				return -EEXIST;
3703 			if (mddev->default_bitmap_offset == 0)
3704 				return -EINVAL;
3705 			mddev->bitmap_offset = mddev->default_bitmap_offset;
3706 			mddev->pers->quiesce(mddev, 1);
3707 			rv = bitmap_create(mddev);
3708 			if (rv)
3709 				bitmap_destroy(mddev);
3710 			mddev->pers->quiesce(mddev, 0);
3711 		} else {
3712 			/* remove the bitmap */
3713 			if (!mddev->bitmap)
3714 				return -ENOENT;
3715 			if (mddev->bitmap->file)
3716 				return -EINVAL;
3717 			mddev->pers->quiesce(mddev, 1);
3718 			bitmap_destroy(mddev);
3719 			mddev->pers->quiesce(mddev, 0);
3720 			mddev->bitmap_offset = 0;
3721 		}
3722 	}
3723 	md_update_sb(mddev);
3724 	return rv;
3725 }
3726 
3727 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
3728 {
3729 	mdk_rdev_t *rdev;
3730 
3731 	if (mddev->pers == NULL)
3732 		return -ENODEV;
3733 
3734 	rdev = find_rdev(mddev, dev);
3735 	if (!rdev)
3736 		return -ENODEV;
3737 
3738 	md_error(mddev, rdev);
3739 	return 0;
3740 }
3741 
3742 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3743 {
3744 	mddev_t *mddev = bdev->bd_disk->private_data;
3745 
3746 	geo->heads = 2;
3747 	geo->sectors = 4;
3748 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
3749 	return 0;
3750 }
3751 
3752 static int md_ioctl(struct inode *inode, struct file *file,
3753 			unsigned int cmd, unsigned long arg)
3754 {
3755 	int err = 0;
3756 	void __user *argp = (void __user *)arg;
3757 	mddev_t *mddev = NULL;
3758 
3759 	if (!capable(CAP_SYS_ADMIN))
3760 		return -EACCES;
3761 
3762 	/*
3763 	 * Commands dealing with the RAID driver but not any
3764 	 * particular array:
3765 	 */
3766 	switch (cmd)
3767 	{
3768 		case RAID_VERSION:
3769 			err = get_version(argp);
3770 			goto done;
3771 
3772 		case PRINT_RAID_DEBUG:
3773 			err = 0;
3774 			md_print_devices();
3775 			goto done;
3776 
3777 #ifndef MODULE
3778 		case RAID_AUTORUN:
3779 			err = 0;
3780 			autostart_arrays(arg);
3781 			goto done;
3782 #endif
3783 		default:;
3784 	}
3785 
3786 	/*
3787 	 * Commands creating/starting a new array:
3788 	 */
3789 
3790 	mddev = inode->i_bdev->bd_disk->private_data;
3791 
3792 	if (!mddev) {
3793 		BUG();
3794 		goto abort;
3795 	}
3796 
3797 
3798 	if (cmd == START_ARRAY) {
3799 		/* START_ARRAY doesn't need to lock the array as autostart_array
3800 		 * does the locking, and it could even be a different array
3801 		 */
3802 		static int cnt = 3;
3803 		if (cnt > 0 ) {
3804 			printk(KERN_WARNING
3805 			       "md: %s(pid %d) used deprecated START_ARRAY ioctl. "
3806 			       "This will not be supported beyond July 2006\n",
3807 			       current->comm, current->pid);
3808 			cnt--;
3809 		}
3810 		err = autostart_array(new_decode_dev(arg));
3811 		if (err) {
3812 			printk(KERN_WARNING "md: autostart failed!\n");
3813 			goto abort;
3814 		}
3815 		goto done;
3816 	}
3817 
3818 	err = mddev_lock(mddev);
3819 	if (err) {
3820 		printk(KERN_INFO
3821 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
3822 			err, cmd);
3823 		goto abort;
3824 	}
3825 
3826 	switch (cmd)
3827 	{
3828 		case SET_ARRAY_INFO:
3829 			{
3830 				mdu_array_info_t info;
3831 				if (!arg)
3832 					memset(&info, 0, sizeof(info));
3833 				else if (copy_from_user(&info, argp, sizeof(info))) {
3834 					err = -EFAULT;
3835 					goto abort_unlock;
3836 				}
3837 				if (mddev->pers) {
3838 					err = update_array_info(mddev, &info);
3839 					if (err) {
3840 						printk(KERN_WARNING "md: couldn't update"
3841 						       " array info. %d\n", err);
3842 						goto abort_unlock;
3843 					}
3844 					goto done_unlock;
3845 				}
3846 				if (!list_empty(&mddev->disks)) {
3847 					printk(KERN_WARNING
3848 					       "md: array %s already has disks!\n",
3849 					       mdname(mddev));
3850 					err = -EBUSY;
3851 					goto abort_unlock;
3852 				}
3853 				if (mddev->raid_disks) {
3854 					printk(KERN_WARNING
3855 					       "md: array %s already initialised!\n",
3856 					       mdname(mddev));
3857 					err = -EBUSY;
3858 					goto abort_unlock;
3859 				}
3860 				err = set_array_info(mddev, &info);
3861 				if (err) {
3862 					printk(KERN_WARNING "md: couldn't set"
3863 					       " array info. %d\n", err);
3864 					goto abort_unlock;
3865 				}
3866 			}
3867 			goto done_unlock;
3868 
3869 		default:;
3870 	}
3871 
3872 	/*
3873 	 * Commands querying/configuring an existing array:
3874 	 */
3875 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
3876 	 * RUN_ARRAY, and SET_BITMAP_FILE are allowed */
3877 	if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
3878 			&& cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE) {
3879 		err = -ENODEV;
3880 		goto abort_unlock;
3881 	}
3882 
3883 	/*
3884 	 * Commands even a read-only array can execute:
3885 	 */
3886 	switch (cmd)
3887 	{
3888 		case GET_ARRAY_INFO:
3889 			err = get_array_info(mddev, argp);
3890 			goto done_unlock;
3891 
3892 		case GET_BITMAP_FILE:
3893 			err = get_bitmap_file(mddev, argp);
3894 			goto done_unlock;
3895 
3896 		case GET_DISK_INFO:
3897 			err = get_disk_info(mddev, argp);
3898 			goto done_unlock;
3899 
3900 		case RESTART_ARRAY_RW:
3901 			err = restart_array(mddev);
3902 			goto done_unlock;
3903 
3904 		case STOP_ARRAY:
3905 			err = do_md_stop (mddev, 0);
3906 			goto done_unlock;
3907 
3908 		case STOP_ARRAY_RO:
3909 			err = do_md_stop (mddev, 1);
3910 			goto done_unlock;
3911 
3912 	/*
3913 	 * We have a problem here : there is no easy way to give a CHS
3914 	 * virtual geometry. We currently pretend that we have a 2 heads
3915 	 * 4 sectors (with a BIG number of cylinders...). This drives
3916 	 * dosfs just mad... ;-)
3917 	 */
3918 	}
3919 
3920 	/*
3921 	 * The remaining ioctls are changing the state of the
3922 	 * superblock, so we do not allow them on read-only arrays.
3923 	 * However non-MD ioctls (e.g. get-size) will still come through
3924 	 * here and hit the 'default' below, so only disallow
3925 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
3926 	 */
3927 	if (_IOC_TYPE(cmd) == MD_MAJOR &&
3928 	    mddev->ro && mddev->pers) {
3929 		if (mddev->ro == 2) {
3930 			mddev->ro = 0;
3931 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3932 		md_wakeup_thread(mddev->thread);
3933 
3934 		} else {
3935 			err = -EROFS;
3936 			goto abort_unlock;
3937 		}
3938 	}
3939 
3940 	switch (cmd)
3941 	{
3942 		case ADD_NEW_DISK:
3943 		{
3944 			mdu_disk_info_t info;
3945 			if (copy_from_user(&info, argp, sizeof(info)))
3946 				err = -EFAULT;
3947 			else
3948 				err = add_new_disk(mddev, &info);
3949 			goto done_unlock;
3950 		}
3951 
3952 		case HOT_REMOVE_DISK:
3953 			err = hot_remove_disk(mddev, new_decode_dev(arg));
3954 			goto done_unlock;
3955 
3956 		case HOT_ADD_DISK:
3957 			err = hot_add_disk(mddev, new_decode_dev(arg));
3958 			goto done_unlock;
3959 
3960 		case SET_DISK_FAULTY:
3961 			err = set_disk_faulty(mddev, new_decode_dev(arg));
3962 			goto done_unlock;
3963 
3964 		case RUN_ARRAY:
3965 			err = do_md_run (mddev);
3966 			goto done_unlock;
3967 
3968 		case SET_BITMAP_FILE:
3969 			err = set_bitmap_file(mddev, (int)arg);
3970 			goto done_unlock;
3971 
3972 		default:
3973 			if (_IOC_TYPE(cmd) == MD_MAJOR)
3974 				printk(KERN_WARNING "md: %s(pid %d) used"
3975 					" obsolete MD ioctl, upgrade your"
3976 					" software to use new ictls.\n",
3977 					current->comm, current->pid);
3978 			err = -EINVAL;
3979 			goto abort_unlock;
3980 	}
3981 
3982 done_unlock:
3983 abort_unlock:
3984 	mddev_unlock(mddev);
3985 
3986 	return err;
3987 done:
3988 	if (err)
3989 		MD_BUG();
3990 abort:
3991 	return err;
3992 }
3993 
3994 static int md_open(struct inode *inode, struct file *file)
3995 {
3996 	/*
3997 	 * Succeed if we can lock the mddev, which confirms that
3998 	 * it isn't being stopped right now.
3999 	 */
4000 	mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
4001 	int err;
4002 
4003 	if ((err = mddev_lock(mddev)))
4004 		goto out;
4005 
4006 	err = 0;
4007 	mddev_get(mddev);
4008 	mddev_unlock(mddev);
4009 
4010 	check_disk_change(inode->i_bdev);
4011  out:
4012 	return err;
4013 }
4014 
4015 static int md_release(struct inode *inode, struct file * file)
4016 {
4017  	mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
4018 
4019 	if (!mddev)
4020 		BUG();
4021 	mddev_put(mddev);
4022 
4023 	return 0;
4024 }
4025 
4026 static int md_media_changed(struct gendisk *disk)
4027 {
4028 	mddev_t *mddev = disk->private_data;
4029 
4030 	return mddev->changed;
4031 }
4032 
4033 static int md_revalidate(struct gendisk *disk)
4034 {
4035 	mddev_t *mddev = disk->private_data;
4036 
4037 	mddev->changed = 0;
4038 	return 0;
4039 }
4040 static struct block_device_operations md_fops =
4041 {
4042 	.owner		= THIS_MODULE,
4043 	.open		= md_open,
4044 	.release	= md_release,
4045 	.ioctl		= md_ioctl,
4046 	.getgeo		= md_getgeo,
4047 	.media_changed	= md_media_changed,
4048 	.revalidate_disk= md_revalidate,
4049 };
4050 
4051 static int md_thread(void * arg)
4052 {
4053 	mdk_thread_t *thread = arg;
4054 
4055 	/*
4056 	 * md_thread is a 'system-thread', it's priority should be very
4057 	 * high. We avoid resource deadlocks individually in each
4058 	 * raid personality. (RAID5 does preallocation) We also use RR and
4059 	 * the very same RT priority as kswapd, thus we will never get
4060 	 * into a priority inversion deadlock.
4061 	 *
4062 	 * we definitely have to have equal or higher priority than
4063 	 * bdflush, otherwise bdflush will deadlock if there are too
4064 	 * many dirty RAID5 blocks.
4065 	 */
4066 
4067 	allow_signal(SIGKILL);
4068 	while (!kthread_should_stop()) {
4069 
4070 		/* We need to wait INTERRUPTIBLE so that
4071 		 * we don't add to the load-average.
4072 		 * That means we need to be sure no signals are
4073 		 * pending
4074 		 */
4075 		if (signal_pending(current))
4076 			flush_signals(current);
4077 
4078 		wait_event_interruptible_timeout
4079 			(thread->wqueue,
4080 			 test_bit(THREAD_WAKEUP, &thread->flags)
4081 			 || kthread_should_stop(),
4082 			 thread->timeout);
4083 		try_to_freeze();
4084 
4085 		clear_bit(THREAD_WAKEUP, &thread->flags);
4086 
4087 		thread->run(thread->mddev);
4088 	}
4089 
4090 	return 0;
4091 }
4092 
4093 void md_wakeup_thread(mdk_thread_t *thread)
4094 {
4095 	if (thread) {
4096 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
4097 		set_bit(THREAD_WAKEUP, &thread->flags);
4098 		wake_up(&thread->wqueue);
4099 	}
4100 }
4101 
4102 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
4103 				 const char *name)
4104 {
4105 	mdk_thread_t *thread;
4106 
4107 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
4108 	if (!thread)
4109 		return NULL;
4110 
4111 	init_waitqueue_head(&thread->wqueue);
4112 
4113 	thread->run = run;
4114 	thread->mddev = mddev;
4115 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
4116 	thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
4117 	if (IS_ERR(thread->tsk)) {
4118 		kfree(thread);
4119 		return NULL;
4120 	}
4121 	return thread;
4122 }
4123 
4124 void md_unregister_thread(mdk_thread_t *thread)
4125 {
4126 	dprintk("interrupting MD-thread pid %d\n", thread->tsk->pid);
4127 
4128 	kthread_stop(thread->tsk);
4129 	kfree(thread);
4130 }
4131 
4132 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
4133 {
4134 	if (!mddev) {
4135 		MD_BUG();
4136 		return;
4137 	}
4138 
4139 	if (!rdev || test_bit(Faulty, &rdev->flags))
4140 		return;
4141 /*
4142 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
4143 		mdname(mddev),
4144 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
4145 		__builtin_return_address(0),__builtin_return_address(1),
4146 		__builtin_return_address(2),__builtin_return_address(3));
4147 */
4148 	if (!mddev->pers->error_handler)
4149 		return;
4150 	mddev->pers->error_handler(mddev,rdev);
4151 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4152 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4153 	md_wakeup_thread(mddev->thread);
4154 	md_new_event(mddev);
4155 }
4156 
4157 /* seq_file implementation /proc/mdstat */
4158 
4159 static void status_unused(struct seq_file *seq)
4160 {
4161 	int i = 0;
4162 	mdk_rdev_t *rdev;
4163 	struct list_head *tmp;
4164 
4165 	seq_printf(seq, "unused devices: ");
4166 
4167 	ITERATE_RDEV_PENDING(rdev,tmp) {
4168 		char b[BDEVNAME_SIZE];
4169 		i++;
4170 		seq_printf(seq, "%s ",
4171 			      bdevname(rdev->bdev,b));
4172 	}
4173 	if (!i)
4174 		seq_printf(seq, "<none>");
4175 
4176 	seq_printf(seq, "\n");
4177 }
4178 
4179 
4180 static void status_resync(struct seq_file *seq, mddev_t * mddev)
4181 {
4182 	sector_t max_blocks, resync, res;
4183 	unsigned long dt, db, rt;
4184 	int scale;
4185 	unsigned int per_milli;
4186 
4187 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
4188 
4189 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4190 		max_blocks = mddev->resync_max_sectors >> 1;
4191 	else
4192 		max_blocks = mddev->size;
4193 
4194 	/*
4195 	 * Should not happen.
4196 	 */
4197 	if (!max_blocks) {
4198 		MD_BUG();
4199 		return;
4200 	}
4201 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
4202 	 * in a sector_t, and (max_blocks>>scale) will fit in a
4203 	 * u32, as those are the requirements for sector_div.
4204 	 * Thus 'scale' must be at least 10
4205 	 */
4206 	scale = 10;
4207 	if (sizeof(sector_t) > sizeof(unsigned long)) {
4208 		while ( max_blocks/2 > (1ULL<<(scale+32)))
4209 			scale++;
4210 	}
4211 	res = (resync>>scale)*1000;
4212 	sector_div(res, (u32)((max_blocks>>scale)+1));
4213 
4214 	per_milli = res;
4215 	{
4216 		int i, x = per_milli/50, y = 20-x;
4217 		seq_printf(seq, "[");
4218 		for (i = 0; i < x; i++)
4219 			seq_printf(seq, "=");
4220 		seq_printf(seq, ">");
4221 		for (i = 0; i < y; i++)
4222 			seq_printf(seq, ".");
4223 		seq_printf(seq, "] ");
4224 	}
4225 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
4226 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
4227 		    "reshape" :
4228 		      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
4229 		       "resync" : "recovery")),
4230 		      per_milli/10, per_milli % 10,
4231 		   (unsigned long long) resync,
4232 		   (unsigned long long) max_blocks);
4233 
4234 	/*
4235 	 * We do not want to overflow, so the order of operands and
4236 	 * the * 100 / 100 trick are important. We do a +1 to be
4237 	 * safe against division by zero. We only estimate anyway.
4238 	 *
4239 	 * dt: time from mark until now
4240 	 * db: blocks written from mark until now
4241 	 * rt: remaining time
4242 	 */
4243 	dt = ((jiffies - mddev->resync_mark) / HZ);
4244 	if (!dt) dt++;
4245 	db = resync - (mddev->resync_mark_cnt/2);
4246 	rt = (dt * ((unsigned long)(max_blocks-resync) / (db/100+1)))/100;
4247 
4248 	seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
4249 
4250 	seq_printf(seq, " speed=%ldK/sec", db/dt);
4251 }
4252 
4253 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
4254 {
4255 	struct list_head *tmp;
4256 	loff_t l = *pos;
4257 	mddev_t *mddev;
4258 
4259 	if (l >= 0x10000)
4260 		return NULL;
4261 	if (!l--)
4262 		/* header */
4263 		return (void*)1;
4264 
4265 	spin_lock(&all_mddevs_lock);
4266 	list_for_each(tmp,&all_mddevs)
4267 		if (!l--) {
4268 			mddev = list_entry(tmp, mddev_t, all_mddevs);
4269 			mddev_get(mddev);
4270 			spin_unlock(&all_mddevs_lock);
4271 			return mddev;
4272 		}
4273 	spin_unlock(&all_mddevs_lock);
4274 	if (!l--)
4275 		return (void*)2;/* tail */
4276 	return NULL;
4277 }
4278 
4279 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4280 {
4281 	struct list_head *tmp;
4282 	mddev_t *next_mddev, *mddev = v;
4283 
4284 	++*pos;
4285 	if (v == (void*)2)
4286 		return NULL;
4287 
4288 	spin_lock(&all_mddevs_lock);
4289 	if (v == (void*)1)
4290 		tmp = all_mddevs.next;
4291 	else
4292 		tmp = mddev->all_mddevs.next;
4293 	if (tmp != &all_mddevs)
4294 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
4295 	else {
4296 		next_mddev = (void*)2;
4297 		*pos = 0x10000;
4298 	}
4299 	spin_unlock(&all_mddevs_lock);
4300 
4301 	if (v != (void*)1)
4302 		mddev_put(mddev);
4303 	return next_mddev;
4304 
4305 }
4306 
4307 static void md_seq_stop(struct seq_file *seq, void *v)
4308 {
4309 	mddev_t *mddev = v;
4310 
4311 	if (mddev && v != (void*)1 && v != (void*)2)
4312 		mddev_put(mddev);
4313 }
4314 
4315 struct mdstat_info {
4316 	int event;
4317 };
4318 
4319 static int md_seq_show(struct seq_file *seq, void *v)
4320 {
4321 	mddev_t *mddev = v;
4322 	sector_t size;
4323 	struct list_head *tmp2;
4324 	mdk_rdev_t *rdev;
4325 	struct mdstat_info *mi = seq->private;
4326 	struct bitmap *bitmap;
4327 
4328 	if (v == (void*)1) {
4329 		struct mdk_personality *pers;
4330 		seq_printf(seq, "Personalities : ");
4331 		spin_lock(&pers_lock);
4332 		list_for_each_entry(pers, &pers_list, list)
4333 			seq_printf(seq, "[%s] ", pers->name);
4334 
4335 		spin_unlock(&pers_lock);
4336 		seq_printf(seq, "\n");
4337 		mi->event = atomic_read(&md_event_count);
4338 		return 0;
4339 	}
4340 	if (v == (void*)2) {
4341 		status_unused(seq);
4342 		return 0;
4343 	}
4344 
4345 	if (mddev_lock(mddev)!=0)
4346 		return -EINTR;
4347 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
4348 		seq_printf(seq, "%s : %sactive", mdname(mddev),
4349 						mddev->pers ? "" : "in");
4350 		if (mddev->pers) {
4351 			if (mddev->ro==1)
4352 				seq_printf(seq, " (read-only)");
4353 			if (mddev->ro==2)
4354 				seq_printf(seq, "(auto-read-only)");
4355 			seq_printf(seq, " %s", mddev->pers->name);
4356 		}
4357 
4358 		size = 0;
4359 		ITERATE_RDEV(mddev,rdev,tmp2) {
4360 			char b[BDEVNAME_SIZE];
4361 			seq_printf(seq, " %s[%d]",
4362 				bdevname(rdev->bdev,b), rdev->desc_nr);
4363 			if (test_bit(WriteMostly, &rdev->flags))
4364 				seq_printf(seq, "(W)");
4365 			if (test_bit(Faulty, &rdev->flags)) {
4366 				seq_printf(seq, "(F)");
4367 				continue;
4368 			} else if (rdev->raid_disk < 0)
4369 				seq_printf(seq, "(S)"); /* spare */
4370 			size += rdev->size;
4371 		}
4372 
4373 		if (!list_empty(&mddev->disks)) {
4374 			if (mddev->pers)
4375 				seq_printf(seq, "\n      %llu blocks",
4376 					(unsigned long long)mddev->array_size);
4377 			else
4378 				seq_printf(seq, "\n      %llu blocks",
4379 					(unsigned long long)size);
4380 		}
4381 		if (mddev->persistent) {
4382 			if (mddev->major_version != 0 ||
4383 			    mddev->minor_version != 90) {
4384 				seq_printf(seq," super %d.%d",
4385 					   mddev->major_version,
4386 					   mddev->minor_version);
4387 			}
4388 		} else
4389 			seq_printf(seq, " super non-persistent");
4390 
4391 		if (mddev->pers) {
4392 			mddev->pers->status (seq, mddev);
4393 	 		seq_printf(seq, "\n      ");
4394 			if (mddev->pers->sync_request) {
4395 				if (mddev->curr_resync > 2) {
4396 					status_resync (seq, mddev);
4397 					seq_printf(seq, "\n      ");
4398 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
4399 					seq_printf(seq, "\tresync=DELAYED\n      ");
4400 				else if (mddev->recovery_cp < MaxSector)
4401 					seq_printf(seq, "\tresync=PENDING\n      ");
4402 			}
4403 		} else
4404 			seq_printf(seq, "\n       ");
4405 
4406 		if ((bitmap = mddev->bitmap)) {
4407 			unsigned long chunk_kb;
4408 			unsigned long flags;
4409 			spin_lock_irqsave(&bitmap->lock, flags);
4410 			chunk_kb = bitmap->chunksize >> 10;
4411 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
4412 				"%lu%s chunk",
4413 				bitmap->pages - bitmap->missing_pages,
4414 				bitmap->pages,
4415 				(bitmap->pages - bitmap->missing_pages)
4416 					<< (PAGE_SHIFT - 10),
4417 				chunk_kb ? chunk_kb : bitmap->chunksize,
4418 				chunk_kb ? "KB" : "B");
4419 			if (bitmap->file) {
4420 				seq_printf(seq, ", file: ");
4421 				seq_path(seq, bitmap->file->f_vfsmnt,
4422 					 bitmap->file->f_dentry," \t\n");
4423 			}
4424 
4425 			seq_printf(seq, "\n");
4426 			spin_unlock_irqrestore(&bitmap->lock, flags);
4427 		}
4428 
4429 		seq_printf(seq, "\n");
4430 	}
4431 	mddev_unlock(mddev);
4432 
4433 	return 0;
4434 }
4435 
4436 static struct seq_operations md_seq_ops = {
4437 	.start  = md_seq_start,
4438 	.next   = md_seq_next,
4439 	.stop   = md_seq_stop,
4440 	.show   = md_seq_show,
4441 };
4442 
4443 static int md_seq_open(struct inode *inode, struct file *file)
4444 {
4445 	int error;
4446 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
4447 	if (mi == NULL)
4448 		return -ENOMEM;
4449 
4450 	error = seq_open(file, &md_seq_ops);
4451 	if (error)
4452 		kfree(mi);
4453 	else {
4454 		struct seq_file *p = file->private_data;
4455 		p->private = mi;
4456 		mi->event = atomic_read(&md_event_count);
4457 	}
4458 	return error;
4459 }
4460 
4461 static int md_seq_release(struct inode *inode, struct file *file)
4462 {
4463 	struct seq_file *m = file->private_data;
4464 	struct mdstat_info *mi = m->private;
4465 	m->private = NULL;
4466 	kfree(mi);
4467 	return seq_release(inode, file);
4468 }
4469 
4470 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
4471 {
4472 	struct seq_file *m = filp->private_data;
4473 	struct mdstat_info *mi = m->private;
4474 	int mask;
4475 
4476 	poll_wait(filp, &md_event_waiters, wait);
4477 
4478 	/* always allow read */
4479 	mask = POLLIN | POLLRDNORM;
4480 
4481 	if (mi->event != atomic_read(&md_event_count))
4482 		mask |= POLLERR | POLLPRI;
4483 	return mask;
4484 }
4485 
4486 static struct file_operations md_seq_fops = {
4487 	.open           = md_seq_open,
4488 	.read           = seq_read,
4489 	.llseek         = seq_lseek,
4490 	.release	= md_seq_release,
4491 	.poll		= mdstat_poll,
4492 };
4493 
4494 int register_md_personality(struct mdk_personality *p)
4495 {
4496 	spin_lock(&pers_lock);
4497 	list_add_tail(&p->list, &pers_list);
4498 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
4499 	spin_unlock(&pers_lock);
4500 	return 0;
4501 }
4502 
4503 int unregister_md_personality(struct mdk_personality *p)
4504 {
4505 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
4506 	spin_lock(&pers_lock);
4507 	list_del_init(&p->list);
4508 	spin_unlock(&pers_lock);
4509 	return 0;
4510 }
4511 
4512 static int is_mddev_idle(mddev_t *mddev)
4513 {
4514 	mdk_rdev_t * rdev;
4515 	struct list_head *tmp;
4516 	int idle;
4517 	unsigned long curr_events;
4518 
4519 	idle = 1;
4520 	ITERATE_RDEV(mddev,rdev,tmp) {
4521 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
4522 		curr_events = disk_stat_read(disk, sectors[0]) +
4523 				disk_stat_read(disk, sectors[1]) -
4524 				atomic_read(&disk->sync_io);
4525 		/* The difference between curr_events and last_events
4526 		 * will be affected by any new non-sync IO (making
4527 		 * curr_events bigger) and any difference in the amount of
4528 		 * in-flight syncio (making current_events bigger or smaller)
4529 		 * The amount in-flight is currently limited to
4530 		 * 32*64K in raid1/10 and 256*PAGE_SIZE in raid5/6
4531 		 * which is at most 4096 sectors.
4532 		 * These numbers are fairly fragile and should be made
4533 		 * more robust, probably by enforcing the
4534 		 * 'window size' that md_do_sync sort-of uses.
4535 		 *
4536 		 * Note: the following is an unsigned comparison.
4537 		 */
4538 		if ((curr_events - rdev->last_events + 4096) > 8192) {
4539 			rdev->last_events = curr_events;
4540 			idle = 0;
4541 		}
4542 	}
4543 	return idle;
4544 }
4545 
4546 void md_done_sync(mddev_t *mddev, int blocks, int ok)
4547 {
4548 	/* another "blocks" (512byte) blocks have been synced */
4549 	atomic_sub(blocks, &mddev->recovery_active);
4550 	wake_up(&mddev->recovery_wait);
4551 	if (!ok) {
4552 		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
4553 		md_wakeup_thread(mddev->thread);
4554 		// stop recovery, signal do_sync ....
4555 	}
4556 }
4557 
4558 
4559 /* md_write_start(mddev, bi)
4560  * If we need to update some array metadata (e.g. 'active' flag
4561  * in superblock) before writing, schedule a superblock update
4562  * and wait for it to complete.
4563  */
4564 void md_write_start(mddev_t *mddev, struct bio *bi)
4565 {
4566 	if (bio_data_dir(bi) != WRITE)
4567 		return;
4568 
4569 	BUG_ON(mddev->ro == 1);
4570 	if (mddev->ro == 2) {
4571 		/* need to switch to read/write */
4572 		mddev->ro = 0;
4573 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4574 		md_wakeup_thread(mddev->thread);
4575 	}
4576 	atomic_inc(&mddev->writes_pending);
4577 	if (mddev->in_sync) {
4578 		spin_lock_irq(&mddev->write_lock);
4579 		if (mddev->in_sync) {
4580 			mddev->in_sync = 0;
4581 			mddev->sb_dirty = 1;
4582 			md_wakeup_thread(mddev->thread);
4583 		}
4584 		spin_unlock_irq(&mddev->write_lock);
4585 	}
4586 	wait_event(mddev->sb_wait, mddev->sb_dirty==0);
4587 }
4588 
4589 void md_write_end(mddev_t *mddev)
4590 {
4591 	if (atomic_dec_and_test(&mddev->writes_pending)) {
4592 		if (mddev->safemode == 2)
4593 			md_wakeup_thread(mddev->thread);
4594 		else
4595 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
4596 	}
4597 }
4598 
4599 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
4600 
4601 #define SYNC_MARKS	10
4602 #define	SYNC_MARK_STEP	(3*HZ)
4603 void md_do_sync(mddev_t *mddev)
4604 {
4605 	mddev_t *mddev2;
4606 	unsigned int currspeed = 0,
4607 		 window;
4608 	sector_t max_sectors,j, io_sectors;
4609 	unsigned long mark[SYNC_MARKS];
4610 	sector_t mark_cnt[SYNC_MARKS];
4611 	int last_mark,m;
4612 	struct list_head *tmp;
4613 	sector_t last_check;
4614 	int skipped = 0;
4615 
4616 	/* just incase thread restarts... */
4617 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
4618 		return;
4619 
4620 	/* we overload curr_resync somewhat here.
4621 	 * 0 == not engaged in resync at all
4622 	 * 2 == checking that there is no conflict with another sync
4623 	 * 1 == like 2, but have yielded to allow conflicting resync to
4624 	 *		commense
4625 	 * other == active in resync - this many blocks
4626 	 *
4627 	 * Before starting a resync we must have set curr_resync to
4628 	 * 2, and then checked that every "conflicting" array has curr_resync
4629 	 * less than ours.  When we find one that is the same or higher
4630 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
4631 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
4632 	 * This will mean we have to start checking from the beginning again.
4633 	 *
4634 	 */
4635 
4636 	do {
4637 		mddev->curr_resync = 2;
4638 
4639 	try_again:
4640 		if (kthread_should_stop()) {
4641 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4642 			goto skip;
4643 		}
4644 		ITERATE_MDDEV(mddev2,tmp) {
4645 			if (mddev2 == mddev)
4646 				continue;
4647 			if (mddev2->curr_resync &&
4648 			    match_mddev_units(mddev,mddev2)) {
4649 				DEFINE_WAIT(wq);
4650 				if (mddev < mddev2 && mddev->curr_resync == 2) {
4651 					/* arbitrarily yield */
4652 					mddev->curr_resync = 1;
4653 					wake_up(&resync_wait);
4654 				}
4655 				if (mddev > mddev2 && mddev->curr_resync == 1)
4656 					/* no need to wait here, we can wait the next
4657 					 * time 'round when curr_resync == 2
4658 					 */
4659 					continue;
4660 				prepare_to_wait(&resync_wait, &wq, TASK_UNINTERRUPTIBLE);
4661 				if (!kthread_should_stop() &&
4662 				    mddev2->curr_resync >= mddev->curr_resync) {
4663 					printk(KERN_INFO "md: delaying resync of %s"
4664 					       " until %s has finished resync (they"
4665 					       " share one or more physical units)\n",
4666 					       mdname(mddev), mdname(mddev2));
4667 					mddev_put(mddev2);
4668 					schedule();
4669 					finish_wait(&resync_wait, &wq);
4670 					goto try_again;
4671 				}
4672 				finish_wait(&resync_wait, &wq);
4673 			}
4674 		}
4675 	} while (mddev->curr_resync < 2);
4676 
4677 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4678 		/* resync follows the size requested by the personality,
4679 		 * which defaults to physical size, but can be virtual size
4680 		 */
4681 		max_sectors = mddev->resync_max_sectors;
4682 		mddev->resync_mismatches = 0;
4683 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4684 		max_sectors = mddev->size << 1;
4685 	else
4686 		/* recovery follows the physical size of devices */
4687 		max_sectors = mddev->size << 1;
4688 
4689 	printk(KERN_INFO "md: syncing RAID array %s\n", mdname(mddev));
4690 	printk(KERN_INFO "md: minimum _guaranteed_ reconstruction speed:"
4691 		" %d KB/sec/disc.\n", speed_min(mddev));
4692 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
4693 	       "(but not more than %d KB/sec) for reconstruction.\n",
4694 	       speed_max(mddev));
4695 
4696 	is_mddev_idle(mddev); /* this also initializes IO event counters */
4697 	/* we don't use the checkpoint if there's a bitmap */
4698 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && !mddev->bitmap
4699 	    && ! test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4700 		j = mddev->recovery_cp;
4701 	else
4702 		j = 0;
4703 	io_sectors = 0;
4704 	for (m = 0; m < SYNC_MARKS; m++) {
4705 		mark[m] = jiffies;
4706 		mark_cnt[m] = io_sectors;
4707 	}
4708 	last_mark = 0;
4709 	mddev->resync_mark = mark[last_mark];
4710 	mddev->resync_mark_cnt = mark_cnt[last_mark];
4711 
4712 	/*
4713 	 * Tune reconstruction:
4714 	 */
4715 	window = 32*(PAGE_SIZE/512);
4716 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
4717 		window/2,(unsigned long long) max_sectors/2);
4718 
4719 	atomic_set(&mddev->recovery_active, 0);
4720 	init_waitqueue_head(&mddev->recovery_wait);
4721 	last_check = 0;
4722 
4723 	if (j>2) {
4724 		printk(KERN_INFO
4725 			"md: resuming recovery of %s from checkpoint.\n",
4726 			mdname(mddev));
4727 		mddev->curr_resync = j;
4728 	}
4729 
4730 	while (j < max_sectors) {
4731 		sector_t sectors;
4732 
4733 		skipped = 0;
4734 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
4735 					    currspeed < speed_min(mddev));
4736 		if (sectors == 0) {
4737 			set_bit(MD_RECOVERY_ERR, &mddev->recovery);
4738 			goto out;
4739 		}
4740 
4741 		if (!skipped) { /* actual IO requested */
4742 			io_sectors += sectors;
4743 			atomic_add(sectors, &mddev->recovery_active);
4744 		}
4745 
4746 		j += sectors;
4747 		if (j>1) mddev->curr_resync = j;
4748 		if (last_check == 0)
4749 			/* this is the earliers that rebuilt will be
4750 			 * visible in /proc/mdstat
4751 			 */
4752 			md_new_event(mddev);
4753 
4754 		if (last_check + window > io_sectors || j == max_sectors)
4755 			continue;
4756 
4757 		last_check = io_sectors;
4758 
4759 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
4760 		    test_bit(MD_RECOVERY_ERR, &mddev->recovery))
4761 			break;
4762 
4763 	repeat:
4764 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
4765 			/* step marks */
4766 			int next = (last_mark+1) % SYNC_MARKS;
4767 
4768 			mddev->resync_mark = mark[next];
4769 			mddev->resync_mark_cnt = mark_cnt[next];
4770 			mark[next] = jiffies;
4771 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
4772 			last_mark = next;
4773 		}
4774 
4775 
4776 		if (kthread_should_stop()) {
4777 			/*
4778 			 * got a signal, exit.
4779 			 */
4780 			printk(KERN_INFO
4781 				"md: md_do_sync() got signal ... exiting\n");
4782 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4783 			goto out;
4784 		}
4785 
4786 		/*
4787 		 * this loop exits only if either when we are slower than
4788 		 * the 'hard' speed limit, or the system was IO-idle for
4789 		 * a jiffy.
4790 		 * the system might be non-idle CPU-wise, but we only care
4791 		 * about not overloading the IO subsystem. (things like an
4792 		 * e2fsck being done on the RAID array should execute fast)
4793 		 */
4794 		mddev->queue->unplug_fn(mddev->queue);
4795 		cond_resched();
4796 
4797 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
4798 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
4799 
4800 		if (currspeed > speed_min(mddev)) {
4801 			if ((currspeed > speed_max(mddev)) ||
4802 					!is_mddev_idle(mddev)) {
4803 				msleep(500);
4804 				goto repeat;
4805 			}
4806 		}
4807 	}
4808 	printk(KERN_INFO "md: %s: sync done.\n",mdname(mddev));
4809 	/*
4810 	 * this also signals 'finished resyncing' to md_stop
4811 	 */
4812  out:
4813 	mddev->queue->unplug_fn(mddev->queue);
4814 
4815 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
4816 
4817 	/* tell personality that we are finished */
4818 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
4819 
4820 	if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
4821 	    test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
4822 	    !test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
4823 	    mddev->curr_resync > 2 &&
4824 	    mddev->curr_resync >= mddev->recovery_cp) {
4825 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4826 			printk(KERN_INFO
4827 				"md: checkpointing recovery of %s.\n",
4828 				mdname(mddev));
4829 			mddev->recovery_cp = mddev->curr_resync;
4830 		} else
4831 			mddev->recovery_cp = MaxSector;
4832 	}
4833 
4834  skip:
4835 	mddev->curr_resync = 0;
4836 	wake_up(&resync_wait);
4837 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
4838 	md_wakeup_thread(mddev->thread);
4839 }
4840 EXPORT_SYMBOL_GPL(md_do_sync);
4841 
4842 
4843 /*
4844  * This routine is regularly called by all per-raid-array threads to
4845  * deal with generic issues like resync and super-block update.
4846  * Raid personalities that don't have a thread (linear/raid0) do not
4847  * need this as they never do any recovery or update the superblock.
4848  *
4849  * It does not do any resync itself, but rather "forks" off other threads
4850  * to do that as needed.
4851  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
4852  * "->recovery" and create a thread at ->sync_thread.
4853  * When the thread finishes it sets MD_RECOVERY_DONE (and might set MD_RECOVERY_ERR)
4854  * and wakeups up this thread which will reap the thread and finish up.
4855  * This thread also removes any faulty devices (with nr_pending == 0).
4856  *
4857  * The overall approach is:
4858  *  1/ if the superblock needs updating, update it.
4859  *  2/ If a recovery thread is running, don't do anything else.
4860  *  3/ If recovery has finished, clean up, possibly marking spares active.
4861  *  4/ If there are any faulty devices, remove them.
4862  *  5/ If array is degraded, try to add spares devices
4863  *  6/ If array has spares or is not in-sync, start a resync thread.
4864  */
4865 void md_check_recovery(mddev_t *mddev)
4866 {
4867 	mdk_rdev_t *rdev;
4868 	struct list_head *rtmp;
4869 
4870 
4871 	if (mddev->bitmap)
4872 		bitmap_daemon_work(mddev->bitmap);
4873 
4874 	if (mddev->ro)
4875 		return;
4876 
4877 	if (signal_pending(current)) {
4878 		if (mddev->pers->sync_request) {
4879 			printk(KERN_INFO "md: %s in immediate safe mode\n",
4880 			       mdname(mddev));
4881 			mddev->safemode = 2;
4882 		}
4883 		flush_signals(current);
4884 	}
4885 
4886 	if ( ! (
4887 		mddev->sb_dirty ||
4888 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
4889 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
4890 		(mddev->safemode == 1) ||
4891 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
4892 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
4893 		))
4894 		return;
4895 
4896 	if (mddev_trylock(mddev)) {
4897 		int spares =0;
4898 
4899 		spin_lock_irq(&mddev->write_lock);
4900 		if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
4901 		    !mddev->in_sync && mddev->recovery_cp == MaxSector) {
4902 			mddev->in_sync = 1;
4903 			mddev->sb_dirty = 1;
4904 		}
4905 		if (mddev->safemode == 1)
4906 			mddev->safemode = 0;
4907 		spin_unlock_irq(&mddev->write_lock);
4908 
4909 		if (mddev->sb_dirty)
4910 			md_update_sb(mddev);
4911 
4912 
4913 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
4914 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
4915 			/* resync/recovery still happening */
4916 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4917 			goto unlock;
4918 		}
4919 		if (mddev->sync_thread) {
4920 			/* resync has finished, collect result */
4921 			md_unregister_thread(mddev->sync_thread);
4922 			mddev->sync_thread = NULL;
4923 			if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
4924 			    !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4925 				/* success...*/
4926 				/* activate any spares */
4927 				mddev->pers->spare_active(mddev);
4928 			}
4929 			md_update_sb(mddev);
4930 
4931 			/* if array is no-longer degraded, then any saved_raid_disk
4932 			 * information must be scrapped
4933 			 */
4934 			if (!mddev->degraded)
4935 				ITERATE_RDEV(mddev,rdev,rtmp)
4936 					rdev->saved_raid_disk = -1;
4937 
4938 			mddev->recovery = 0;
4939 			/* flag recovery needed just to double check */
4940 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4941 			md_new_event(mddev);
4942 			goto unlock;
4943 		}
4944 		/* Clear some bits that don't mean anything, but
4945 		 * might be left set
4946 		 */
4947 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4948 		clear_bit(MD_RECOVERY_ERR, &mddev->recovery);
4949 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
4950 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
4951 
4952 		/* no recovery is running.
4953 		 * remove any failed drives, then
4954 		 * add spares if possible.
4955 		 * Spare are also removed and re-added, to allow
4956 		 * the personality to fail the re-add.
4957 		 */
4958 		ITERATE_RDEV(mddev,rdev,rtmp)
4959 			if (rdev->raid_disk >= 0 &&
4960 			    (test_bit(Faulty, &rdev->flags) || ! test_bit(In_sync, &rdev->flags)) &&
4961 			    atomic_read(&rdev->nr_pending)==0) {
4962 				if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0) {
4963 					char nm[20];
4964 					sprintf(nm,"rd%d", rdev->raid_disk);
4965 					sysfs_remove_link(&mddev->kobj, nm);
4966 					rdev->raid_disk = -1;
4967 				}
4968 			}
4969 
4970 		if (mddev->degraded) {
4971 			ITERATE_RDEV(mddev,rdev,rtmp)
4972 				if (rdev->raid_disk < 0
4973 				    && !test_bit(Faulty, &rdev->flags)) {
4974 					if (mddev->pers->hot_add_disk(mddev,rdev)) {
4975 						char nm[20];
4976 						sprintf(nm, "rd%d", rdev->raid_disk);
4977 						sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
4978 						spares++;
4979 						md_new_event(mddev);
4980 					} else
4981 						break;
4982 				}
4983 		}
4984 
4985 		if (spares) {
4986 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4987 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4988 		} else if (mddev->recovery_cp < MaxSector) {
4989 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4990 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4991 			/* nothing to be done ... */
4992 			goto unlock;
4993 
4994 		if (mddev->pers->sync_request) {
4995 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4996 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
4997 				/* We are adding a device or devices to an array
4998 				 * which has the bitmap stored on all devices.
4999 				 * So make sure all bitmap pages get written
5000 				 */
5001 				bitmap_write_all(mddev->bitmap);
5002 			}
5003 			mddev->sync_thread = md_register_thread(md_do_sync,
5004 								mddev,
5005 								"%s_resync");
5006 			if (!mddev->sync_thread) {
5007 				printk(KERN_ERR "%s: could not start resync"
5008 					" thread...\n",
5009 					mdname(mddev));
5010 				/* leave the spares where they are, it shouldn't hurt */
5011 				mddev->recovery = 0;
5012 			} else
5013 				md_wakeup_thread(mddev->sync_thread);
5014 			md_new_event(mddev);
5015 		}
5016 	unlock:
5017 		mddev_unlock(mddev);
5018 	}
5019 }
5020 
5021 static int md_notify_reboot(struct notifier_block *this,
5022 			    unsigned long code, void *x)
5023 {
5024 	struct list_head *tmp;
5025 	mddev_t *mddev;
5026 
5027 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
5028 
5029 		printk(KERN_INFO "md: stopping all md devices.\n");
5030 
5031 		ITERATE_MDDEV(mddev,tmp)
5032 			if (mddev_trylock(mddev))
5033 				do_md_stop (mddev, 1);
5034 		/*
5035 		 * certain more exotic SCSI devices are known to be
5036 		 * volatile wrt too early system reboots. While the
5037 		 * right place to handle this issue is the given
5038 		 * driver, we do want to have a safe RAID driver ...
5039 		 */
5040 		mdelay(1000*1);
5041 	}
5042 	return NOTIFY_DONE;
5043 }
5044 
5045 static struct notifier_block md_notifier = {
5046 	.notifier_call	= md_notify_reboot,
5047 	.next		= NULL,
5048 	.priority	= INT_MAX, /* before any real devices */
5049 };
5050 
5051 static void md_geninit(void)
5052 {
5053 	struct proc_dir_entry *p;
5054 
5055 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
5056 
5057 	p = create_proc_entry("mdstat", S_IRUGO, NULL);
5058 	if (p)
5059 		p->proc_fops = &md_seq_fops;
5060 }
5061 
5062 static int __init md_init(void)
5063 {
5064 	int minor;
5065 
5066 	printk(KERN_INFO "md: md driver %d.%d.%d MAX_MD_DEVS=%d,"
5067 			" MD_SB_DISKS=%d\n",
5068 			MD_MAJOR_VERSION, MD_MINOR_VERSION,
5069 			MD_PATCHLEVEL_VERSION, MAX_MD_DEVS, MD_SB_DISKS);
5070 	printk(KERN_INFO "md: bitmap version %d.%d\n", BITMAP_MAJOR_HI,
5071 			BITMAP_MINOR);
5072 
5073 	if (register_blkdev(MAJOR_NR, "md"))
5074 		return -1;
5075 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
5076 		unregister_blkdev(MAJOR_NR, "md");
5077 		return -1;
5078 	}
5079 	devfs_mk_dir("md");
5080 	blk_register_region(MKDEV(MAJOR_NR, 0), MAX_MD_DEVS, THIS_MODULE,
5081 				md_probe, NULL, NULL);
5082 	blk_register_region(MKDEV(mdp_major, 0), MAX_MD_DEVS<<MdpMinorShift, THIS_MODULE,
5083 			    md_probe, NULL, NULL);
5084 
5085 	for (minor=0; minor < MAX_MD_DEVS; ++minor)
5086 		devfs_mk_bdev(MKDEV(MAJOR_NR, minor),
5087 				S_IFBLK|S_IRUSR|S_IWUSR,
5088 				"md/%d", minor);
5089 
5090 	for (minor=0; minor < MAX_MD_DEVS; ++minor)
5091 		devfs_mk_bdev(MKDEV(mdp_major, minor<<MdpMinorShift),
5092 			      S_IFBLK|S_IRUSR|S_IWUSR,
5093 			      "md/mdp%d", minor);
5094 
5095 
5096 	register_reboot_notifier(&md_notifier);
5097 	raid_table_header = register_sysctl_table(raid_root_table, 1);
5098 
5099 	md_geninit();
5100 	return (0);
5101 }
5102 
5103 
5104 #ifndef MODULE
5105 
5106 /*
5107  * Searches all registered partitions for autorun RAID arrays
5108  * at boot time.
5109  */
5110 static dev_t detected_devices[128];
5111 static int dev_cnt;
5112 
5113 void md_autodetect_dev(dev_t dev)
5114 {
5115 	if (dev_cnt >= 0 && dev_cnt < 127)
5116 		detected_devices[dev_cnt++] = dev;
5117 }
5118 
5119 
5120 static void autostart_arrays(int part)
5121 {
5122 	mdk_rdev_t *rdev;
5123 	int i;
5124 
5125 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
5126 
5127 	for (i = 0; i < dev_cnt; i++) {
5128 		dev_t dev = detected_devices[i];
5129 
5130 		rdev = md_import_device(dev,0, 0);
5131 		if (IS_ERR(rdev))
5132 			continue;
5133 
5134 		if (test_bit(Faulty, &rdev->flags)) {
5135 			MD_BUG();
5136 			continue;
5137 		}
5138 		list_add(&rdev->same_set, &pending_raid_disks);
5139 	}
5140 	dev_cnt = 0;
5141 
5142 	autorun_devices(part);
5143 }
5144 
5145 #endif
5146 
5147 static __exit void md_exit(void)
5148 {
5149 	mddev_t *mddev;
5150 	struct list_head *tmp;
5151 	int i;
5152 	blk_unregister_region(MKDEV(MAJOR_NR,0), MAX_MD_DEVS);
5153 	blk_unregister_region(MKDEV(mdp_major,0), MAX_MD_DEVS << MdpMinorShift);
5154 	for (i=0; i < MAX_MD_DEVS; i++)
5155 		devfs_remove("md/%d", i);
5156 	for (i=0; i < MAX_MD_DEVS; i++)
5157 		devfs_remove("md/d%d", i);
5158 
5159 	devfs_remove("md");
5160 
5161 	unregister_blkdev(MAJOR_NR,"md");
5162 	unregister_blkdev(mdp_major, "mdp");
5163 	unregister_reboot_notifier(&md_notifier);
5164 	unregister_sysctl_table(raid_table_header);
5165 	remove_proc_entry("mdstat", NULL);
5166 	ITERATE_MDDEV(mddev,tmp) {
5167 		struct gendisk *disk = mddev->gendisk;
5168 		if (!disk)
5169 			continue;
5170 		export_array(mddev);
5171 		del_gendisk(disk);
5172 		put_disk(disk);
5173 		mddev->gendisk = NULL;
5174 		mddev_put(mddev);
5175 	}
5176 }
5177 
5178 module_init(md_init)
5179 module_exit(md_exit)
5180 
5181 static int get_ro(char *buffer, struct kernel_param *kp)
5182 {
5183 	return sprintf(buffer, "%d", start_readonly);
5184 }
5185 static int set_ro(const char *val, struct kernel_param *kp)
5186 {
5187 	char *e;
5188 	int num = simple_strtoul(val, &e, 10);
5189 	if (*val && (*e == '\0' || *e == '\n')) {
5190 		start_readonly = num;
5191 		return 0;
5192 	}
5193 	return -EINVAL;
5194 }
5195 
5196 module_param_call(start_ro, set_ro, get_ro, NULL, 0600);
5197 module_param(start_dirty_degraded, int, 0644);
5198 
5199 
5200 EXPORT_SYMBOL(register_md_personality);
5201 EXPORT_SYMBOL(unregister_md_personality);
5202 EXPORT_SYMBOL(md_error);
5203 EXPORT_SYMBOL(md_done_sync);
5204 EXPORT_SYMBOL(md_write_start);
5205 EXPORT_SYMBOL(md_write_end);
5206 EXPORT_SYMBOL(md_register_thread);
5207 EXPORT_SYMBOL(md_unregister_thread);
5208 EXPORT_SYMBOL(md_wakeup_thread);
5209 EXPORT_SYMBOL(md_print_devices);
5210 EXPORT_SYMBOL(md_check_recovery);
5211 MODULE_LICENSE("GPL");
5212 MODULE_ALIAS("md");
5213 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
5214