xref: /openbmc/linux/drivers/md/md.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/raid/md.h>
37 #include <linux/raid/bitmap.h>
38 #include <linux/sysctl.h>
39 #include <linux/buffer_head.h> /* for invalidate_bdev */
40 #include <linux/poll.h>
41 #include <linux/ctype.h>
42 #include <linux/hdreg.h>
43 #include <linux/proc_fs.h>
44 #include <linux/random.h>
45 #include <linux/reboot.h>
46 #include <linux/file.h>
47 #include <linux/delay.h>
48 
49 #define MAJOR_NR MD_MAJOR
50 
51 /* 63 partitions with the alternate major number (mdp) */
52 #define MdpMinorShift 6
53 
54 #define DEBUG 0
55 #define dprintk(x...) ((void)(DEBUG && printk(x)))
56 
57 
58 #ifndef MODULE
59 static void autostart_arrays(int part);
60 #endif
61 
62 static LIST_HEAD(pers_list);
63 static DEFINE_SPINLOCK(pers_lock);
64 
65 static void md_print_devices(void);
66 
67 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
68 
69 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
70 
71 /*
72  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
73  * is 1000 KB/sec, so the extra system load does not show up that much.
74  * Increase it if you want to have more _guaranteed_ speed. Note that
75  * the RAID driver will use the maximum available bandwidth if the IO
76  * subsystem is idle. There is also an 'absolute maximum' reconstruction
77  * speed limit - in case reconstruction slows down your system despite
78  * idle IO detection.
79  *
80  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
81  * or /sys/block/mdX/md/sync_speed_{min,max}
82  */
83 
84 static int sysctl_speed_limit_min = 1000;
85 static int sysctl_speed_limit_max = 200000;
86 static inline int speed_min(mddev_t *mddev)
87 {
88 	return mddev->sync_speed_min ?
89 		mddev->sync_speed_min : sysctl_speed_limit_min;
90 }
91 
92 static inline int speed_max(mddev_t *mddev)
93 {
94 	return mddev->sync_speed_max ?
95 		mddev->sync_speed_max : sysctl_speed_limit_max;
96 }
97 
98 static struct ctl_table_header *raid_table_header;
99 
100 static ctl_table raid_table[] = {
101 	{
102 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MIN,
103 		.procname	= "speed_limit_min",
104 		.data		= &sysctl_speed_limit_min,
105 		.maxlen		= sizeof(int),
106 		.mode		= S_IRUGO|S_IWUSR,
107 		.proc_handler	= &proc_dointvec,
108 	},
109 	{
110 		.ctl_name	= DEV_RAID_SPEED_LIMIT_MAX,
111 		.procname	= "speed_limit_max",
112 		.data		= &sysctl_speed_limit_max,
113 		.maxlen		= sizeof(int),
114 		.mode		= S_IRUGO|S_IWUSR,
115 		.proc_handler	= &proc_dointvec,
116 	},
117 	{ .ctl_name = 0 }
118 };
119 
120 static ctl_table raid_dir_table[] = {
121 	{
122 		.ctl_name	= DEV_RAID,
123 		.procname	= "raid",
124 		.maxlen		= 0,
125 		.mode		= S_IRUGO|S_IXUGO,
126 		.child		= raid_table,
127 	},
128 	{ .ctl_name = 0 }
129 };
130 
131 static ctl_table raid_root_table[] = {
132 	{
133 		.ctl_name	= CTL_DEV,
134 		.procname	= "dev",
135 		.maxlen		= 0,
136 		.mode		= 0555,
137 		.child		= raid_dir_table,
138 	},
139 	{ .ctl_name = 0 }
140 };
141 
142 static struct block_device_operations md_fops;
143 
144 static int start_readonly;
145 
146 /*
147  * We have a system wide 'event count' that is incremented
148  * on any 'interesting' event, and readers of /proc/mdstat
149  * can use 'poll' or 'select' to find out when the event
150  * count increases.
151  *
152  * Events are:
153  *  start array, stop array, error, add device, remove device,
154  *  start build, activate spare
155  */
156 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
157 static atomic_t md_event_count;
158 void md_new_event(mddev_t *mddev)
159 {
160 	atomic_inc(&md_event_count);
161 	wake_up(&md_event_waiters);
162 }
163 EXPORT_SYMBOL_GPL(md_new_event);
164 
165 /* Alternate version that can be called from interrupts
166  * when calling sysfs_notify isn't needed.
167  */
168 static void md_new_event_inintr(mddev_t *mddev)
169 {
170 	atomic_inc(&md_event_count);
171 	wake_up(&md_event_waiters);
172 }
173 
174 /*
175  * Enables to iterate over all existing md arrays
176  * all_mddevs_lock protects this list.
177  */
178 static LIST_HEAD(all_mddevs);
179 static DEFINE_SPINLOCK(all_mddevs_lock);
180 
181 
182 /*
183  * iterates through all used mddevs in the system.
184  * We take care to grab the all_mddevs_lock whenever navigating
185  * the list, and to always hold a refcount when unlocked.
186  * Any code which breaks out of this loop while own
187  * a reference to the current mddev and must mddev_put it.
188  */
189 #define for_each_mddev(mddev,tmp)					\
190 									\
191 	for (({ spin_lock(&all_mddevs_lock); 				\
192 		tmp = all_mddevs.next;					\
193 		mddev = NULL;});					\
194 	     ({ if (tmp != &all_mddevs)					\
195 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
196 		spin_unlock(&all_mddevs_lock);				\
197 		if (mddev) mddev_put(mddev);				\
198 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
199 		tmp != &all_mddevs;});					\
200 	     ({ spin_lock(&all_mddevs_lock);				\
201 		tmp = tmp->next;})					\
202 		)
203 
204 
205 static int md_fail_request(struct request_queue *q, struct bio *bio)
206 {
207 	bio_io_error(bio);
208 	return 0;
209 }
210 
211 static inline mddev_t *mddev_get(mddev_t *mddev)
212 {
213 	atomic_inc(&mddev->active);
214 	return mddev;
215 }
216 
217 static void mddev_delayed_delete(struct work_struct *ws);
218 
219 static void mddev_put(mddev_t *mddev)
220 {
221 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
222 		return;
223 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
224 	    !mddev->hold_active) {
225 		list_del(&mddev->all_mddevs);
226 		if (mddev->gendisk) {
227 			/* we did a probe so need to clean up.
228 			 * Call schedule_work inside the spinlock
229 			 * so that flush_scheduled_work() after
230 			 * mddev_find will succeed in waiting for the
231 			 * work to be done.
232 			 */
233 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
234 			schedule_work(&mddev->del_work);
235 		} else
236 			kfree(mddev);
237 	}
238 	spin_unlock(&all_mddevs_lock);
239 }
240 
241 static mddev_t * mddev_find(dev_t unit)
242 {
243 	mddev_t *mddev, *new = NULL;
244 
245  retry:
246 	spin_lock(&all_mddevs_lock);
247 
248 	if (unit) {
249 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
250 			if (mddev->unit == unit) {
251 				mddev_get(mddev);
252 				spin_unlock(&all_mddevs_lock);
253 				kfree(new);
254 				return mddev;
255 			}
256 
257 		if (new) {
258 			list_add(&new->all_mddevs, &all_mddevs);
259 			spin_unlock(&all_mddevs_lock);
260 			new->hold_active = UNTIL_IOCTL;
261 			return new;
262 		}
263 	} else if (new) {
264 		/* find an unused unit number */
265 		static int next_minor = 512;
266 		int start = next_minor;
267 		int is_free = 0;
268 		int dev = 0;
269 		while (!is_free) {
270 			dev = MKDEV(MD_MAJOR, next_minor);
271 			next_minor++;
272 			if (next_minor > MINORMASK)
273 				next_minor = 0;
274 			if (next_minor == start) {
275 				/* Oh dear, all in use. */
276 				spin_unlock(&all_mddevs_lock);
277 				kfree(new);
278 				return NULL;
279 			}
280 
281 			is_free = 1;
282 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
283 				if (mddev->unit == dev) {
284 					is_free = 0;
285 					break;
286 				}
287 		}
288 		new->unit = dev;
289 		new->md_minor = MINOR(dev);
290 		new->hold_active = UNTIL_STOP;
291 		list_add(&new->all_mddevs, &all_mddevs);
292 		spin_unlock(&all_mddevs_lock);
293 		return new;
294 	}
295 	spin_unlock(&all_mddevs_lock);
296 
297 	new = kzalloc(sizeof(*new), GFP_KERNEL);
298 	if (!new)
299 		return NULL;
300 
301 	new->unit = unit;
302 	if (MAJOR(unit) == MD_MAJOR)
303 		new->md_minor = MINOR(unit);
304 	else
305 		new->md_minor = MINOR(unit) >> MdpMinorShift;
306 
307 	mutex_init(&new->reconfig_mutex);
308 	INIT_LIST_HEAD(&new->disks);
309 	INIT_LIST_HEAD(&new->all_mddevs);
310 	init_timer(&new->safemode_timer);
311 	atomic_set(&new->active, 1);
312 	atomic_set(&new->openers, 0);
313 	spin_lock_init(&new->write_lock);
314 	init_waitqueue_head(&new->sb_wait);
315 	init_waitqueue_head(&new->recovery_wait);
316 	new->reshape_position = MaxSector;
317 	new->resync_min = 0;
318 	new->resync_max = MaxSector;
319 	new->level = LEVEL_NONE;
320 
321 	goto retry;
322 }
323 
324 static inline int mddev_lock(mddev_t * mddev)
325 {
326 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
327 }
328 
329 static inline int mddev_trylock(mddev_t * mddev)
330 {
331 	return mutex_trylock(&mddev->reconfig_mutex);
332 }
333 
334 static inline void mddev_unlock(mddev_t * mddev)
335 {
336 	mutex_unlock(&mddev->reconfig_mutex);
337 
338 	md_wakeup_thread(mddev->thread);
339 }
340 
341 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
342 {
343 	mdk_rdev_t *rdev;
344 
345 	list_for_each_entry(rdev, &mddev->disks, same_set)
346 		if (rdev->desc_nr == nr)
347 			return rdev;
348 
349 	return NULL;
350 }
351 
352 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
353 {
354 	mdk_rdev_t *rdev;
355 
356 	list_for_each_entry(rdev, &mddev->disks, same_set)
357 		if (rdev->bdev->bd_dev == dev)
358 			return rdev;
359 
360 	return NULL;
361 }
362 
363 static struct mdk_personality *find_pers(int level, char *clevel)
364 {
365 	struct mdk_personality *pers;
366 	list_for_each_entry(pers, &pers_list, list) {
367 		if (level != LEVEL_NONE && pers->level == level)
368 			return pers;
369 		if (strcmp(pers->name, clevel)==0)
370 			return pers;
371 	}
372 	return NULL;
373 }
374 
375 /* return the offset of the super block in 512byte sectors */
376 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
377 {
378 	sector_t num_sectors = bdev->bd_inode->i_size / 512;
379 	return MD_NEW_SIZE_SECTORS(num_sectors);
380 }
381 
382 static sector_t calc_num_sectors(mdk_rdev_t *rdev, unsigned chunk_size)
383 {
384 	sector_t num_sectors = rdev->sb_start;
385 
386 	if (chunk_size)
387 		num_sectors &= ~((sector_t)chunk_size/512 - 1);
388 	return num_sectors;
389 }
390 
391 static int alloc_disk_sb(mdk_rdev_t * rdev)
392 {
393 	if (rdev->sb_page)
394 		MD_BUG();
395 
396 	rdev->sb_page = alloc_page(GFP_KERNEL);
397 	if (!rdev->sb_page) {
398 		printk(KERN_ALERT "md: out of memory.\n");
399 		return -ENOMEM;
400 	}
401 
402 	return 0;
403 }
404 
405 static void free_disk_sb(mdk_rdev_t * rdev)
406 {
407 	if (rdev->sb_page) {
408 		put_page(rdev->sb_page);
409 		rdev->sb_loaded = 0;
410 		rdev->sb_page = NULL;
411 		rdev->sb_start = 0;
412 		rdev->size = 0;
413 	}
414 }
415 
416 
417 static void super_written(struct bio *bio, int error)
418 {
419 	mdk_rdev_t *rdev = bio->bi_private;
420 	mddev_t *mddev = rdev->mddev;
421 
422 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
423 		printk("md: super_written gets error=%d, uptodate=%d\n",
424 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
425 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
426 		md_error(mddev, rdev);
427 	}
428 
429 	if (atomic_dec_and_test(&mddev->pending_writes))
430 		wake_up(&mddev->sb_wait);
431 	bio_put(bio);
432 }
433 
434 static void super_written_barrier(struct bio *bio, int error)
435 {
436 	struct bio *bio2 = bio->bi_private;
437 	mdk_rdev_t *rdev = bio2->bi_private;
438 	mddev_t *mddev = rdev->mddev;
439 
440 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
441 	    error == -EOPNOTSUPP) {
442 		unsigned long flags;
443 		/* barriers don't appear to be supported :-( */
444 		set_bit(BarriersNotsupp, &rdev->flags);
445 		mddev->barriers_work = 0;
446 		spin_lock_irqsave(&mddev->write_lock, flags);
447 		bio2->bi_next = mddev->biolist;
448 		mddev->biolist = bio2;
449 		spin_unlock_irqrestore(&mddev->write_lock, flags);
450 		wake_up(&mddev->sb_wait);
451 		bio_put(bio);
452 	} else {
453 		bio_put(bio2);
454 		bio->bi_private = rdev;
455 		super_written(bio, error);
456 	}
457 }
458 
459 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
460 		   sector_t sector, int size, struct page *page)
461 {
462 	/* write first size bytes of page to sector of rdev
463 	 * Increment mddev->pending_writes before returning
464 	 * and decrement it on completion, waking up sb_wait
465 	 * if zero is reached.
466 	 * If an error occurred, call md_error
467 	 *
468 	 * As we might need to resubmit the request if BIO_RW_BARRIER
469 	 * causes ENOTSUPP, we allocate a spare bio...
470 	 */
471 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
472 	int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNCIO) | (1<<BIO_RW_UNPLUG);
473 
474 	bio->bi_bdev = rdev->bdev;
475 	bio->bi_sector = sector;
476 	bio_add_page(bio, page, size, 0);
477 	bio->bi_private = rdev;
478 	bio->bi_end_io = super_written;
479 	bio->bi_rw = rw;
480 
481 	atomic_inc(&mddev->pending_writes);
482 	if (!test_bit(BarriersNotsupp, &rdev->flags)) {
483 		struct bio *rbio;
484 		rw |= (1<<BIO_RW_BARRIER);
485 		rbio = bio_clone(bio, GFP_NOIO);
486 		rbio->bi_private = bio;
487 		rbio->bi_end_io = super_written_barrier;
488 		submit_bio(rw, rbio);
489 	} else
490 		submit_bio(rw, bio);
491 }
492 
493 void md_super_wait(mddev_t *mddev)
494 {
495 	/* wait for all superblock writes that were scheduled to complete.
496 	 * if any had to be retried (due to BARRIER problems), retry them
497 	 */
498 	DEFINE_WAIT(wq);
499 	for(;;) {
500 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
501 		if (atomic_read(&mddev->pending_writes)==0)
502 			break;
503 		while (mddev->biolist) {
504 			struct bio *bio;
505 			spin_lock_irq(&mddev->write_lock);
506 			bio = mddev->biolist;
507 			mddev->biolist = bio->bi_next ;
508 			bio->bi_next = NULL;
509 			spin_unlock_irq(&mddev->write_lock);
510 			submit_bio(bio->bi_rw, bio);
511 		}
512 		schedule();
513 	}
514 	finish_wait(&mddev->sb_wait, &wq);
515 }
516 
517 static void bi_complete(struct bio *bio, int error)
518 {
519 	complete((struct completion*)bio->bi_private);
520 }
521 
522 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
523 		   struct page *page, int rw)
524 {
525 	struct bio *bio = bio_alloc(GFP_NOIO, 1);
526 	struct completion event;
527 	int ret;
528 
529 	rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
530 
531 	bio->bi_bdev = bdev;
532 	bio->bi_sector = sector;
533 	bio_add_page(bio, page, size, 0);
534 	init_completion(&event);
535 	bio->bi_private = &event;
536 	bio->bi_end_io = bi_complete;
537 	submit_bio(rw, bio);
538 	wait_for_completion(&event);
539 
540 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
541 	bio_put(bio);
542 	return ret;
543 }
544 EXPORT_SYMBOL_GPL(sync_page_io);
545 
546 static int read_disk_sb(mdk_rdev_t * rdev, int size)
547 {
548 	char b[BDEVNAME_SIZE];
549 	if (!rdev->sb_page) {
550 		MD_BUG();
551 		return -EINVAL;
552 	}
553 	if (rdev->sb_loaded)
554 		return 0;
555 
556 
557 	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
558 		goto fail;
559 	rdev->sb_loaded = 1;
560 	return 0;
561 
562 fail:
563 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
564 		bdevname(rdev->bdev,b));
565 	return -EINVAL;
566 }
567 
568 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
569 {
570 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
571 		sb1->set_uuid1 == sb2->set_uuid1 &&
572 		sb1->set_uuid2 == sb2->set_uuid2 &&
573 		sb1->set_uuid3 == sb2->set_uuid3;
574 }
575 
576 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
577 {
578 	int ret;
579 	mdp_super_t *tmp1, *tmp2;
580 
581 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
582 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
583 
584 	if (!tmp1 || !tmp2) {
585 		ret = 0;
586 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
587 		goto abort;
588 	}
589 
590 	*tmp1 = *sb1;
591 	*tmp2 = *sb2;
592 
593 	/*
594 	 * nr_disks is not constant
595 	 */
596 	tmp1->nr_disks = 0;
597 	tmp2->nr_disks = 0;
598 
599 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
600 abort:
601 	kfree(tmp1);
602 	kfree(tmp2);
603 	return ret;
604 }
605 
606 
607 static u32 md_csum_fold(u32 csum)
608 {
609 	csum = (csum & 0xffff) + (csum >> 16);
610 	return (csum & 0xffff) + (csum >> 16);
611 }
612 
613 static unsigned int calc_sb_csum(mdp_super_t * sb)
614 {
615 	u64 newcsum = 0;
616 	u32 *sb32 = (u32*)sb;
617 	int i;
618 	unsigned int disk_csum, csum;
619 
620 	disk_csum = sb->sb_csum;
621 	sb->sb_csum = 0;
622 
623 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
624 		newcsum += sb32[i];
625 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
626 
627 
628 #ifdef CONFIG_ALPHA
629 	/* This used to use csum_partial, which was wrong for several
630 	 * reasons including that different results are returned on
631 	 * different architectures.  It isn't critical that we get exactly
632 	 * the same return value as before (we always csum_fold before
633 	 * testing, and that removes any differences).  However as we
634 	 * know that csum_partial always returned a 16bit value on
635 	 * alphas, do a fold to maximise conformity to previous behaviour.
636 	 */
637 	sb->sb_csum = md_csum_fold(disk_csum);
638 #else
639 	sb->sb_csum = disk_csum;
640 #endif
641 	return csum;
642 }
643 
644 
645 /*
646  * Handle superblock details.
647  * We want to be able to handle multiple superblock formats
648  * so we have a common interface to them all, and an array of
649  * different handlers.
650  * We rely on user-space to write the initial superblock, and support
651  * reading and updating of superblocks.
652  * Interface methods are:
653  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
654  *      loads and validates a superblock on dev.
655  *      if refdev != NULL, compare superblocks on both devices
656  *    Return:
657  *      0 - dev has a superblock that is compatible with refdev
658  *      1 - dev has a superblock that is compatible and newer than refdev
659  *          so dev should be used as the refdev in future
660  *     -EINVAL superblock incompatible or invalid
661  *     -othererror e.g. -EIO
662  *
663  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
664  *      Verify that dev is acceptable into mddev.
665  *       The first time, mddev->raid_disks will be 0, and data from
666  *       dev should be merged in.  Subsequent calls check that dev
667  *       is new enough.  Return 0 or -EINVAL
668  *
669  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
670  *     Update the superblock for rdev with data in mddev
671  *     This does not write to disc.
672  *
673  */
674 
675 struct super_type  {
676 	char		    *name;
677 	struct module	    *owner;
678 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
679 					  int minor_version);
680 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
681 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
682 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
683 						sector_t num_sectors);
684 };
685 
686 /*
687  * load_super for 0.90.0
688  */
689 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
690 {
691 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
692 	mdp_super_t *sb;
693 	int ret;
694 
695 	/*
696 	 * Calculate the position of the superblock (512byte sectors),
697 	 * it's at the end of the disk.
698 	 *
699 	 * It also happens to be a multiple of 4Kb.
700 	 */
701 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
702 
703 	ret = read_disk_sb(rdev, MD_SB_BYTES);
704 	if (ret) return ret;
705 
706 	ret = -EINVAL;
707 
708 	bdevname(rdev->bdev, b);
709 	sb = (mdp_super_t*)page_address(rdev->sb_page);
710 
711 	if (sb->md_magic != MD_SB_MAGIC) {
712 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
713 		       b);
714 		goto abort;
715 	}
716 
717 	if (sb->major_version != 0 ||
718 	    sb->minor_version < 90 ||
719 	    sb->minor_version > 91) {
720 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
721 			sb->major_version, sb->minor_version,
722 			b);
723 		goto abort;
724 	}
725 
726 	if (sb->raid_disks <= 0)
727 		goto abort;
728 
729 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
730 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
731 			b);
732 		goto abort;
733 	}
734 
735 	rdev->preferred_minor = sb->md_minor;
736 	rdev->data_offset = 0;
737 	rdev->sb_size = MD_SB_BYTES;
738 
739 	if (sb->state & (1<<MD_SB_BITMAP_PRESENT)) {
740 		if (sb->level != 1 && sb->level != 4
741 		    && sb->level != 5 && sb->level != 6
742 		    && sb->level != 10) {
743 			/* FIXME use a better test */
744 			printk(KERN_WARNING
745 			       "md: bitmaps not supported for this level.\n");
746 			goto abort;
747 		}
748 	}
749 
750 	if (sb->level == LEVEL_MULTIPATH)
751 		rdev->desc_nr = -1;
752 	else
753 		rdev->desc_nr = sb->this_disk.number;
754 
755 	if (!refdev) {
756 		ret = 1;
757 	} else {
758 		__u64 ev1, ev2;
759 		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
760 		if (!uuid_equal(refsb, sb)) {
761 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
762 				b, bdevname(refdev->bdev,b2));
763 			goto abort;
764 		}
765 		if (!sb_equal(refsb, sb)) {
766 			printk(KERN_WARNING "md: %s has same UUID"
767 			       " but different superblock to %s\n",
768 			       b, bdevname(refdev->bdev, b2));
769 			goto abort;
770 		}
771 		ev1 = md_event(sb);
772 		ev2 = md_event(refsb);
773 		if (ev1 > ev2)
774 			ret = 1;
775 		else
776 			ret = 0;
777 	}
778 	rdev->size = calc_num_sectors(rdev, sb->chunk_size) / 2;
779 
780 	if (rdev->size < sb->size && sb->level > 1)
781 		/* "this cannot possibly happen" ... */
782 		ret = -EINVAL;
783 
784  abort:
785 	return ret;
786 }
787 
788 /*
789  * validate_super for 0.90.0
790  */
791 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
792 {
793 	mdp_disk_t *desc;
794 	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
795 	__u64 ev1 = md_event(sb);
796 
797 	rdev->raid_disk = -1;
798 	clear_bit(Faulty, &rdev->flags);
799 	clear_bit(In_sync, &rdev->flags);
800 	clear_bit(WriteMostly, &rdev->flags);
801 	clear_bit(BarriersNotsupp, &rdev->flags);
802 
803 	if (mddev->raid_disks == 0) {
804 		mddev->major_version = 0;
805 		mddev->minor_version = sb->minor_version;
806 		mddev->patch_version = sb->patch_version;
807 		mddev->external = 0;
808 		mddev->chunk_size = sb->chunk_size;
809 		mddev->ctime = sb->ctime;
810 		mddev->utime = sb->utime;
811 		mddev->level = sb->level;
812 		mddev->clevel[0] = 0;
813 		mddev->layout = sb->layout;
814 		mddev->raid_disks = sb->raid_disks;
815 		mddev->size = sb->size;
816 		mddev->events = ev1;
817 		mddev->bitmap_offset = 0;
818 		mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
819 
820 		if (mddev->minor_version >= 91) {
821 			mddev->reshape_position = sb->reshape_position;
822 			mddev->delta_disks = sb->delta_disks;
823 			mddev->new_level = sb->new_level;
824 			mddev->new_layout = sb->new_layout;
825 			mddev->new_chunk = sb->new_chunk;
826 		} else {
827 			mddev->reshape_position = MaxSector;
828 			mddev->delta_disks = 0;
829 			mddev->new_level = mddev->level;
830 			mddev->new_layout = mddev->layout;
831 			mddev->new_chunk = mddev->chunk_size;
832 		}
833 
834 		if (sb->state & (1<<MD_SB_CLEAN))
835 			mddev->recovery_cp = MaxSector;
836 		else {
837 			if (sb->events_hi == sb->cp_events_hi &&
838 				sb->events_lo == sb->cp_events_lo) {
839 				mddev->recovery_cp = sb->recovery_cp;
840 			} else
841 				mddev->recovery_cp = 0;
842 		}
843 
844 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
845 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
846 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
847 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
848 
849 		mddev->max_disks = MD_SB_DISKS;
850 
851 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
852 		    mddev->bitmap_file == NULL)
853 			mddev->bitmap_offset = mddev->default_bitmap_offset;
854 
855 	} else if (mddev->pers == NULL) {
856 		/* Insist on good event counter while assembling */
857 		++ev1;
858 		if (ev1 < mddev->events)
859 			return -EINVAL;
860 	} else if (mddev->bitmap) {
861 		/* if adding to array with a bitmap, then we can accept an
862 		 * older device ... but not too old.
863 		 */
864 		if (ev1 < mddev->bitmap->events_cleared)
865 			return 0;
866 	} else {
867 		if (ev1 < mddev->events)
868 			/* just a hot-add of a new device, leave raid_disk at -1 */
869 			return 0;
870 	}
871 
872 	if (mddev->level != LEVEL_MULTIPATH) {
873 		desc = sb->disks + rdev->desc_nr;
874 
875 		if (desc->state & (1<<MD_DISK_FAULTY))
876 			set_bit(Faulty, &rdev->flags);
877 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
878 			    desc->raid_disk < mddev->raid_disks */) {
879 			set_bit(In_sync, &rdev->flags);
880 			rdev->raid_disk = desc->raid_disk;
881 		}
882 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
883 			set_bit(WriteMostly, &rdev->flags);
884 	} else /* MULTIPATH are always insync */
885 		set_bit(In_sync, &rdev->flags);
886 	return 0;
887 }
888 
889 /*
890  * sync_super for 0.90.0
891  */
892 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
893 {
894 	mdp_super_t *sb;
895 	mdk_rdev_t *rdev2;
896 	int next_spare = mddev->raid_disks;
897 
898 
899 	/* make rdev->sb match mddev data..
900 	 *
901 	 * 1/ zero out disks
902 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
903 	 * 3/ any empty disks < next_spare become removed
904 	 *
905 	 * disks[0] gets initialised to REMOVED because
906 	 * we cannot be sure from other fields if it has
907 	 * been initialised or not.
908 	 */
909 	int i;
910 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
911 
912 	rdev->sb_size = MD_SB_BYTES;
913 
914 	sb = (mdp_super_t*)page_address(rdev->sb_page);
915 
916 	memset(sb, 0, sizeof(*sb));
917 
918 	sb->md_magic = MD_SB_MAGIC;
919 	sb->major_version = mddev->major_version;
920 	sb->patch_version = mddev->patch_version;
921 	sb->gvalid_words  = 0; /* ignored */
922 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
923 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
924 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
925 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
926 
927 	sb->ctime = mddev->ctime;
928 	sb->level = mddev->level;
929 	sb->size  = mddev->size;
930 	sb->raid_disks = mddev->raid_disks;
931 	sb->md_minor = mddev->md_minor;
932 	sb->not_persistent = 0;
933 	sb->utime = mddev->utime;
934 	sb->state = 0;
935 	sb->events_hi = (mddev->events>>32);
936 	sb->events_lo = (u32)mddev->events;
937 
938 	if (mddev->reshape_position == MaxSector)
939 		sb->minor_version = 90;
940 	else {
941 		sb->minor_version = 91;
942 		sb->reshape_position = mddev->reshape_position;
943 		sb->new_level = mddev->new_level;
944 		sb->delta_disks = mddev->delta_disks;
945 		sb->new_layout = mddev->new_layout;
946 		sb->new_chunk = mddev->new_chunk;
947 	}
948 	mddev->minor_version = sb->minor_version;
949 	if (mddev->in_sync)
950 	{
951 		sb->recovery_cp = mddev->recovery_cp;
952 		sb->cp_events_hi = (mddev->events>>32);
953 		sb->cp_events_lo = (u32)mddev->events;
954 		if (mddev->recovery_cp == MaxSector)
955 			sb->state = (1<< MD_SB_CLEAN);
956 	} else
957 		sb->recovery_cp = 0;
958 
959 	sb->layout = mddev->layout;
960 	sb->chunk_size = mddev->chunk_size;
961 
962 	if (mddev->bitmap && mddev->bitmap_file == NULL)
963 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
964 
965 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
966 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
967 		mdp_disk_t *d;
968 		int desc_nr;
969 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
970 		    && !test_bit(Faulty, &rdev2->flags))
971 			desc_nr = rdev2->raid_disk;
972 		else
973 			desc_nr = next_spare++;
974 		rdev2->desc_nr = desc_nr;
975 		d = &sb->disks[rdev2->desc_nr];
976 		nr_disks++;
977 		d->number = rdev2->desc_nr;
978 		d->major = MAJOR(rdev2->bdev->bd_dev);
979 		d->minor = MINOR(rdev2->bdev->bd_dev);
980 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
981 		    && !test_bit(Faulty, &rdev2->flags))
982 			d->raid_disk = rdev2->raid_disk;
983 		else
984 			d->raid_disk = rdev2->desc_nr; /* compatibility */
985 		if (test_bit(Faulty, &rdev2->flags))
986 			d->state = (1<<MD_DISK_FAULTY);
987 		else if (test_bit(In_sync, &rdev2->flags)) {
988 			d->state = (1<<MD_DISK_ACTIVE);
989 			d->state |= (1<<MD_DISK_SYNC);
990 			active++;
991 			working++;
992 		} else {
993 			d->state = 0;
994 			spare++;
995 			working++;
996 		}
997 		if (test_bit(WriteMostly, &rdev2->flags))
998 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
999 	}
1000 	/* now set the "removed" and "faulty" bits on any missing devices */
1001 	for (i=0 ; i < mddev->raid_disks ; i++) {
1002 		mdp_disk_t *d = &sb->disks[i];
1003 		if (d->state == 0 && d->number == 0) {
1004 			d->number = i;
1005 			d->raid_disk = i;
1006 			d->state = (1<<MD_DISK_REMOVED);
1007 			d->state |= (1<<MD_DISK_FAULTY);
1008 			failed++;
1009 		}
1010 	}
1011 	sb->nr_disks = nr_disks;
1012 	sb->active_disks = active;
1013 	sb->working_disks = working;
1014 	sb->failed_disks = failed;
1015 	sb->spare_disks = spare;
1016 
1017 	sb->this_disk = sb->disks[rdev->desc_nr];
1018 	sb->sb_csum = calc_sb_csum(sb);
1019 }
1020 
1021 /*
1022  * rdev_size_change for 0.90.0
1023  */
1024 static unsigned long long
1025 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1026 {
1027 	if (num_sectors && num_sectors < rdev->mddev->size * 2)
1028 		return 0; /* component must fit device */
1029 	if (rdev->mddev->bitmap_offset)
1030 		return 0; /* can't move bitmap */
1031 	rdev->sb_start = calc_dev_sboffset(rdev->bdev);
1032 	if (!num_sectors || num_sectors > rdev->sb_start)
1033 		num_sectors = rdev->sb_start;
1034 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1035 		       rdev->sb_page);
1036 	md_super_wait(rdev->mddev);
1037 	return num_sectors / 2; /* kB for sysfs */
1038 }
1039 
1040 
1041 /*
1042  * version 1 superblock
1043  */
1044 
1045 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1046 {
1047 	__le32 disk_csum;
1048 	u32 csum;
1049 	unsigned long long newcsum;
1050 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1051 	__le32 *isuper = (__le32*)sb;
1052 	int i;
1053 
1054 	disk_csum = sb->sb_csum;
1055 	sb->sb_csum = 0;
1056 	newcsum = 0;
1057 	for (i=0; size>=4; size -= 4 )
1058 		newcsum += le32_to_cpu(*isuper++);
1059 
1060 	if (size == 2)
1061 		newcsum += le16_to_cpu(*(__le16*) isuper);
1062 
1063 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1064 	sb->sb_csum = disk_csum;
1065 	return cpu_to_le32(csum);
1066 }
1067 
1068 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1069 {
1070 	struct mdp_superblock_1 *sb;
1071 	int ret;
1072 	sector_t sb_start;
1073 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1074 	int bmask;
1075 
1076 	/*
1077 	 * Calculate the position of the superblock in 512byte sectors.
1078 	 * It is always aligned to a 4K boundary and
1079 	 * depeding on minor_version, it can be:
1080 	 * 0: At least 8K, but less than 12K, from end of device
1081 	 * 1: At start of device
1082 	 * 2: 4K from start of device.
1083 	 */
1084 	switch(minor_version) {
1085 	case 0:
1086 		sb_start = rdev->bdev->bd_inode->i_size >> 9;
1087 		sb_start -= 8*2;
1088 		sb_start &= ~(sector_t)(4*2-1);
1089 		break;
1090 	case 1:
1091 		sb_start = 0;
1092 		break;
1093 	case 2:
1094 		sb_start = 8;
1095 		break;
1096 	default:
1097 		return -EINVAL;
1098 	}
1099 	rdev->sb_start = sb_start;
1100 
1101 	/* superblock is rarely larger than 1K, but it can be larger,
1102 	 * and it is safe to read 4k, so we do that
1103 	 */
1104 	ret = read_disk_sb(rdev, 4096);
1105 	if (ret) return ret;
1106 
1107 
1108 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1109 
1110 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1111 	    sb->major_version != cpu_to_le32(1) ||
1112 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1113 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1114 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1115 		return -EINVAL;
1116 
1117 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1118 		printk("md: invalid superblock checksum on %s\n",
1119 			bdevname(rdev->bdev,b));
1120 		return -EINVAL;
1121 	}
1122 	if (le64_to_cpu(sb->data_size) < 10) {
1123 		printk("md: data_size too small on %s\n",
1124 		       bdevname(rdev->bdev,b));
1125 		return -EINVAL;
1126 	}
1127 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET)) {
1128 		if (sb->level != cpu_to_le32(1) &&
1129 		    sb->level != cpu_to_le32(4) &&
1130 		    sb->level != cpu_to_le32(5) &&
1131 		    sb->level != cpu_to_le32(6) &&
1132 		    sb->level != cpu_to_le32(10)) {
1133 			printk(KERN_WARNING
1134 			       "md: bitmaps not supported for this level.\n");
1135 			return -EINVAL;
1136 		}
1137 	}
1138 
1139 	rdev->preferred_minor = 0xffff;
1140 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1141 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1142 
1143 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1144 	bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
1145 	if (rdev->sb_size & bmask)
1146 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1147 
1148 	if (minor_version
1149 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1150 		return -EINVAL;
1151 
1152 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1153 		rdev->desc_nr = -1;
1154 	else
1155 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1156 
1157 	if (!refdev) {
1158 		ret = 1;
1159 	} else {
1160 		__u64 ev1, ev2;
1161 		struct mdp_superblock_1 *refsb =
1162 			(struct mdp_superblock_1*)page_address(refdev->sb_page);
1163 
1164 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1165 		    sb->level != refsb->level ||
1166 		    sb->layout != refsb->layout ||
1167 		    sb->chunksize != refsb->chunksize) {
1168 			printk(KERN_WARNING "md: %s has strangely different"
1169 				" superblock to %s\n",
1170 				bdevname(rdev->bdev,b),
1171 				bdevname(refdev->bdev,b2));
1172 			return -EINVAL;
1173 		}
1174 		ev1 = le64_to_cpu(sb->events);
1175 		ev2 = le64_to_cpu(refsb->events);
1176 
1177 		if (ev1 > ev2)
1178 			ret = 1;
1179 		else
1180 			ret = 0;
1181 	}
1182 	if (minor_version)
1183 		rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
1184 	else
1185 		rdev->size = rdev->sb_start / 2;
1186 	if (rdev->size < le64_to_cpu(sb->data_size)/2)
1187 		return -EINVAL;
1188 	rdev->size = le64_to_cpu(sb->data_size)/2;
1189 	if (le32_to_cpu(sb->chunksize))
1190 		rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
1191 
1192 	if (le64_to_cpu(sb->size) > rdev->size*2)
1193 		return -EINVAL;
1194 	return ret;
1195 }
1196 
1197 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1198 {
1199 	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1200 	__u64 ev1 = le64_to_cpu(sb->events);
1201 
1202 	rdev->raid_disk = -1;
1203 	clear_bit(Faulty, &rdev->flags);
1204 	clear_bit(In_sync, &rdev->flags);
1205 	clear_bit(WriteMostly, &rdev->flags);
1206 	clear_bit(BarriersNotsupp, &rdev->flags);
1207 
1208 	if (mddev->raid_disks == 0) {
1209 		mddev->major_version = 1;
1210 		mddev->patch_version = 0;
1211 		mddev->external = 0;
1212 		mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
1213 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1214 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1215 		mddev->level = le32_to_cpu(sb->level);
1216 		mddev->clevel[0] = 0;
1217 		mddev->layout = le32_to_cpu(sb->layout);
1218 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1219 		mddev->size = le64_to_cpu(sb->size)/2;
1220 		mddev->events = ev1;
1221 		mddev->bitmap_offset = 0;
1222 		mddev->default_bitmap_offset = 1024 >> 9;
1223 
1224 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1225 		memcpy(mddev->uuid, sb->set_uuid, 16);
1226 
1227 		mddev->max_disks =  (4096-256)/2;
1228 
1229 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1230 		    mddev->bitmap_file == NULL )
1231 			mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
1232 
1233 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1234 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1235 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1236 			mddev->new_level = le32_to_cpu(sb->new_level);
1237 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1238 			mddev->new_chunk = le32_to_cpu(sb->new_chunk)<<9;
1239 		} else {
1240 			mddev->reshape_position = MaxSector;
1241 			mddev->delta_disks = 0;
1242 			mddev->new_level = mddev->level;
1243 			mddev->new_layout = mddev->layout;
1244 			mddev->new_chunk = mddev->chunk_size;
1245 		}
1246 
1247 	} else if (mddev->pers == NULL) {
1248 		/* Insist of good event counter while assembling */
1249 		++ev1;
1250 		if (ev1 < mddev->events)
1251 			return -EINVAL;
1252 	} else if (mddev->bitmap) {
1253 		/* If adding to array with a bitmap, then we can accept an
1254 		 * older device, but not too old.
1255 		 */
1256 		if (ev1 < mddev->bitmap->events_cleared)
1257 			return 0;
1258 	} else {
1259 		if (ev1 < mddev->events)
1260 			/* just a hot-add of a new device, leave raid_disk at -1 */
1261 			return 0;
1262 	}
1263 	if (mddev->level != LEVEL_MULTIPATH) {
1264 		int role;
1265 		role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1266 		switch(role) {
1267 		case 0xffff: /* spare */
1268 			break;
1269 		case 0xfffe: /* faulty */
1270 			set_bit(Faulty, &rdev->flags);
1271 			break;
1272 		default:
1273 			if ((le32_to_cpu(sb->feature_map) &
1274 			     MD_FEATURE_RECOVERY_OFFSET))
1275 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1276 			else
1277 				set_bit(In_sync, &rdev->flags);
1278 			rdev->raid_disk = role;
1279 			break;
1280 		}
1281 		if (sb->devflags & WriteMostly1)
1282 			set_bit(WriteMostly, &rdev->flags);
1283 	} else /* MULTIPATH are always insync */
1284 		set_bit(In_sync, &rdev->flags);
1285 
1286 	return 0;
1287 }
1288 
1289 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1290 {
1291 	struct mdp_superblock_1 *sb;
1292 	mdk_rdev_t *rdev2;
1293 	int max_dev, i;
1294 	/* make rdev->sb match mddev and rdev data. */
1295 
1296 	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1297 
1298 	sb->feature_map = 0;
1299 	sb->pad0 = 0;
1300 	sb->recovery_offset = cpu_to_le64(0);
1301 	memset(sb->pad1, 0, sizeof(sb->pad1));
1302 	memset(sb->pad2, 0, sizeof(sb->pad2));
1303 	memset(sb->pad3, 0, sizeof(sb->pad3));
1304 
1305 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1306 	sb->events = cpu_to_le64(mddev->events);
1307 	if (mddev->in_sync)
1308 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1309 	else
1310 		sb->resync_offset = cpu_to_le64(0);
1311 
1312 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1313 
1314 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1315 	sb->size = cpu_to_le64(mddev->size<<1);
1316 
1317 	if (mddev->bitmap && mddev->bitmap_file == NULL) {
1318 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1319 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1320 	}
1321 
1322 	if (rdev->raid_disk >= 0 &&
1323 	    !test_bit(In_sync, &rdev->flags) &&
1324 	    rdev->recovery_offset > 0) {
1325 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1326 		sb->recovery_offset = cpu_to_le64(rdev->recovery_offset);
1327 	}
1328 
1329 	if (mddev->reshape_position != MaxSector) {
1330 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1331 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1332 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1333 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1334 		sb->new_level = cpu_to_le32(mddev->new_level);
1335 		sb->new_chunk = cpu_to_le32(mddev->new_chunk>>9);
1336 	}
1337 
1338 	max_dev = 0;
1339 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1340 		if (rdev2->desc_nr+1 > max_dev)
1341 			max_dev = rdev2->desc_nr+1;
1342 
1343 	if (max_dev > le32_to_cpu(sb->max_dev))
1344 		sb->max_dev = cpu_to_le32(max_dev);
1345 	for (i=0; i<max_dev;i++)
1346 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1347 
1348 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1349 		i = rdev2->desc_nr;
1350 		if (test_bit(Faulty, &rdev2->flags))
1351 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1352 		else if (test_bit(In_sync, &rdev2->flags))
1353 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1354 		else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
1355 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1356 		else
1357 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1358 	}
1359 
1360 	sb->sb_csum = calc_sb_1_csum(sb);
1361 }
1362 
1363 static unsigned long long
1364 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1365 {
1366 	struct mdp_superblock_1 *sb;
1367 	sector_t max_sectors;
1368 	if (num_sectors && num_sectors < rdev->mddev->size * 2)
1369 		return 0; /* component must fit device */
1370 	if (rdev->sb_start < rdev->data_offset) {
1371 		/* minor versions 1 and 2; superblock before data */
1372 		max_sectors = rdev->bdev->bd_inode->i_size >> 9;
1373 		max_sectors -= rdev->data_offset;
1374 		if (!num_sectors || num_sectors > max_sectors)
1375 			num_sectors = max_sectors;
1376 	} else if (rdev->mddev->bitmap_offset) {
1377 		/* minor version 0 with bitmap we can't move */
1378 		return 0;
1379 	} else {
1380 		/* minor version 0; superblock after data */
1381 		sector_t sb_start;
1382 		sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
1383 		sb_start &= ~(sector_t)(4*2 - 1);
1384 		max_sectors = rdev->size * 2 + sb_start - rdev->sb_start;
1385 		if (!num_sectors || num_sectors > max_sectors)
1386 			num_sectors = max_sectors;
1387 		rdev->sb_start = sb_start;
1388 	}
1389 	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
1390 	sb->data_size = cpu_to_le64(num_sectors);
1391 	sb->super_offset = rdev->sb_start;
1392 	sb->sb_csum = calc_sb_1_csum(sb);
1393 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1394 		       rdev->sb_page);
1395 	md_super_wait(rdev->mddev);
1396 	return num_sectors / 2; /* kB for sysfs */
1397 }
1398 
1399 static struct super_type super_types[] = {
1400 	[0] = {
1401 		.name	= "0.90.0",
1402 		.owner	= THIS_MODULE,
1403 		.load_super	    = super_90_load,
1404 		.validate_super	    = super_90_validate,
1405 		.sync_super	    = super_90_sync,
1406 		.rdev_size_change   = super_90_rdev_size_change,
1407 	},
1408 	[1] = {
1409 		.name	= "md-1",
1410 		.owner	= THIS_MODULE,
1411 		.load_super	    = super_1_load,
1412 		.validate_super	    = super_1_validate,
1413 		.sync_super	    = super_1_sync,
1414 		.rdev_size_change   = super_1_rdev_size_change,
1415 	},
1416 };
1417 
1418 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1419 {
1420 	mdk_rdev_t *rdev, *rdev2;
1421 
1422 	rcu_read_lock();
1423 	rdev_for_each_rcu(rdev, mddev1)
1424 		rdev_for_each_rcu(rdev2, mddev2)
1425 			if (rdev->bdev->bd_contains ==
1426 			    rdev2->bdev->bd_contains) {
1427 				rcu_read_unlock();
1428 				return 1;
1429 			}
1430 	rcu_read_unlock();
1431 	return 0;
1432 }
1433 
1434 static LIST_HEAD(pending_raid_disks);
1435 
1436 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1437 {
1438 	char b[BDEVNAME_SIZE];
1439 	struct kobject *ko;
1440 	char *s;
1441 	int err;
1442 
1443 	if (rdev->mddev) {
1444 		MD_BUG();
1445 		return -EINVAL;
1446 	}
1447 
1448 	/* prevent duplicates */
1449 	if (find_rdev(mddev, rdev->bdev->bd_dev))
1450 		return -EEXIST;
1451 
1452 	/* make sure rdev->size exceeds mddev->size */
1453 	if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
1454 		if (mddev->pers) {
1455 			/* Cannot change size, so fail
1456 			 * If mddev->level <= 0, then we don't care
1457 			 * about aligning sizes (e.g. linear)
1458 			 */
1459 			if (mddev->level > 0)
1460 				return -ENOSPC;
1461 		} else
1462 			mddev->size = rdev->size;
1463 	}
1464 
1465 	/* Verify rdev->desc_nr is unique.
1466 	 * If it is -1, assign a free number, else
1467 	 * check number is not in use
1468 	 */
1469 	if (rdev->desc_nr < 0) {
1470 		int choice = 0;
1471 		if (mddev->pers) choice = mddev->raid_disks;
1472 		while (find_rdev_nr(mddev, choice))
1473 			choice++;
1474 		rdev->desc_nr = choice;
1475 	} else {
1476 		if (find_rdev_nr(mddev, rdev->desc_nr))
1477 			return -EBUSY;
1478 	}
1479 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
1480 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
1481 		       mdname(mddev), mddev->max_disks);
1482 		return -EBUSY;
1483 	}
1484 	bdevname(rdev->bdev,b);
1485 	while ( (s=strchr(b, '/')) != NULL)
1486 		*s = '!';
1487 
1488 	rdev->mddev = mddev;
1489 	printk(KERN_INFO "md: bind<%s>\n", b);
1490 
1491 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
1492 		goto fail;
1493 
1494 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
1495 	if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
1496 		kobject_del(&rdev->kobj);
1497 		goto fail;
1498 	}
1499 	rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, "state");
1500 
1501 	list_add_rcu(&rdev->same_set, &mddev->disks);
1502 	bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
1503 
1504 	/* May as well allow recovery to be retried once */
1505 	mddev->recovery_disabled = 0;
1506 	return 0;
1507 
1508  fail:
1509 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
1510 	       b, mdname(mddev));
1511 	return err;
1512 }
1513 
1514 static void md_delayed_delete(struct work_struct *ws)
1515 {
1516 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
1517 	kobject_del(&rdev->kobj);
1518 	kobject_put(&rdev->kobj);
1519 }
1520 
1521 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1522 {
1523 	char b[BDEVNAME_SIZE];
1524 	if (!rdev->mddev) {
1525 		MD_BUG();
1526 		return;
1527 	}
1528 	bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
1529 	list_del_rcu(&rdev->same_set);
1530 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1531 	rdev->mddev = NULL;
1532 	sysfs_remove_link(&rdev->kobj, "block");
1533 	sysfs_put(rdev->sysfs_state);
1534 	rdev->sysfs_state = NULL;
1535 	/* We need to delay this, otherwise we can deadlock when
1536 	 * writing to 'remove' to "dev/state".  We also need
1537 	 * to delay it due to rcu usage.
1538 	 */
1539 	synchronize_rcu();
1540 	INIT_WORK(&rdev->del_work, md_delayed_delete);
1541 	kobject_get(&rdev->kobj);
1542 	schedule_work(&rdev->del_work);
1543 }
1544 
1545 /*
1546  * prevent the device from being mounted, repartitioned or
1547  * otherwise reused by a RAID array (or any other kernel
1548  * subsystem), by bd_claiming the device.
1549  */
1550 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
1551 {
1552 	int err = 0;
1553 	struct block_device *bdev;
1554 	char b[BDEVNAME_SIZE];
1555 
1556 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1557 	if (IS_ERR(bdev)) {
1558 		printk(KERN_ERR "md: could not open %s.\n",
1559 			__bdevname(dev, b));
1560 		return PTR_ERR(bdev);
1561 	}
1562 	err = bd_claim(bdev, shared ? (mdk_rdev_t *)lock_rdev : rdev);
1563 	if (err) {
1564 		printk(KERN_ERR "md: could not bd_claim %s.\n",
1565 			bdevname(bdev, b));
1566 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1567 		return err;
1568 	}
1569 	if (!shared)
1570 		set_bit(AllReserved, &rdev->flags);
1571 	rdev->bdev = bdev;
1572 	return err;
1573 }
1574 
1575 static void unlock_rdev(mdk_rdev_t *rdev)
1576 {
1577 	struct block_device *bdev = rdev->bdev;
1578 	rdev->bdev = NULL;
1579 	if (!bdev)
1580 		MD_BUG();
1581 	bd_release(bdev);
1582 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1583 }
1584 
1585 void md_autodetect_dev(dev_t dev);
1586 
1587 static void export_rdev(mdk_rdev_t * rdev)
1588 {
1589 	char b[BDEVNAME_SIZE];
1590 	printk(KERN_INFO "md: export_rdev(%s)\n",
1591 		bdevname(rdev->bdev,b));
1592 	if (rdev->mddev)
1593 		MD_BUG();
1594 	free_disk_sb(rdev);
1595 #ifndef MODULE
1596 	if (test_bit(AutoDetected, &rdev->flags))
1597 		md_autodetect_dev(rdev->bdev->bd_dev);
1598 #endif
1599 	unlock_rdev(rdev);
1600 	kobject_put(&rdev->kobj);
1601 }
1602 
1603 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1604 {
1605 	unbind_rdev_from_array(rdev);
1606 	export_rdev(rdev);
1607 }
1608 
1609 static void export_array(mddev_t *mddev)
1610 {
1611 	mdk_rdev_t *rdev, *tmp;
1612 
1613 	rdev_for_each(rdev, tmp, mddev) {
1614 		if (!rdev->mddev) {
1615 			MD_BUG();
1616 			continue;
1617 		}
1618 		kick_rdev_from_array(rdev);
1619 	}
1620 	if (!list_empty(&mddev->disks))
1621 		MD_BUG();
1622 	mddev->raid_disks = 0;
1623 	mddev->major_version = 0;
1624 }
1625 
1626 static void print_desc(mdp_disk_t *desc)
1627 {
1628 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1629 		desc->major,desc->minor,desc->raid_disk,desc->state);
1630 }
1631 
1632 static void print_sb_90(mdp_super_t *sb)
1633 {
1634 	int i;
1635 
1636 	printk(KERN_INFO
1637 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1638 		sb->major_version, sb->minor_version, sb->patch_version,
1639 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1640 		sb->ctime);
1641 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1642 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1643 		sb->md_minor, sb->layout, sb->chunk_size);
1644 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1645 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
1646 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
1647 		sb->failed_disks, sb->spare_disks,
1648 		sb->sb_csum, (unsigned long)sb->events_lo);
1649 
1650 	printk(KERN_INFO);
1651 	for (i = 0; i < MD_SB_DISKS; i++) {
1652 		mdp_disk_t *desc;
1653 
1654 		desc = sb->disks + i;
1655 		if (desc->number || desc->major || desc->minor ||
1656 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
1657 			printk("     D %2d: ", i);
1658 			print_desc(desc);
1659 		}
1660 	}
1661 	printk(KERN_INFO "md:     THIS: ");
1662 	print_desc(&sb->this_disk);
1663 }
1664 
1665 static void print_sb_1(struct mdp_superblock_1 *sb)
1666 {
1667 	__u8 *uuid;
1668 
1669 	uuid = sb->set_uuid;
1670 	printk(KERN_INFO "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%02x%02x%02x%02x"
1671 			":%02x%02x:%02x%02x:%02x%02x:%02x%02x%02x%02x%02x%02x>\n"
1672 	       KERN_INFO "md:    Name: \"%s\" CT:%llu\n",
1673 		le32_to_cpu(sb->major_version),
1674 		le32_to_cpu(sb->feature_map),
1675 		uuid[0], uuid[1], uuid[2], uuid[3],
1676 		uuid[4], uuid[5], uuid[6], uuid[7],
1677 		uuid[8], uuid[9], uuid[10], uuid[11],
1678 		uuid[12], uuid[13], uuid[14], uuid[15],
1679 		sb->set_name,
1680 		(unsigned long long)le64_to_cpu(sb->ctime)
1681 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
1682 
1683 	uuid = sb->device_uuid;
1684 	printk(KERN_INFO "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
1685 			" RO:%llu\n"
1686 	       KERN_INFO "md:     Dev:%08x UUID: %02x%02x%02x%02x:%02x%02x:%02x%02x:%02x%02x"
1687 			":%02x%02x%02x%02x%02x%02x\n"
1688 	       KERN_INFO "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
1689 	       KERN_INFO "md:         (MaxDev:%u) \n",
1690 		le32_to_cpu(sb->level),
1691 		(unsigned long long)le64_to_cpu(sb->size),
1692 		le32_to_cpu(sb->raid_disks),
1693 		le32_to_cpu(sb->layout),
1694 		le32_to_cpu(sb->chunksize),
1695 		(unsigned long long)le64_to_cpu(sb->data_offset),
1696 		(unsigned long long)le64_to_cpu(sb->data_size),
1697 		(unsigned long long)le64_to_cpu(sb->super_offset),
1698 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
1699 		le32_to_cpu(sb->dev_number),
1700 		uuid[0], uuid[1], uuid[2], uuid[3],
1701 		uuid[4], uuid[5], uuid[6], uuid[7],
1702 		uuid[8], uuid[9], uuid[10], uuid[11],
1703 		uuid[12], uuid[13], uuid[14], uuid[15],
1704 		sb->devflags,
1705 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
1706 		(unsigned long long)le64_to_cpu(sb->events),
1707 		(unsigned long long)le64_to_cpu(sb->resync_offset),
1708 		le32_to_cpu(sb->sb_csum),
1709 		le32_to_cpu(sb->max_dev)
1710 		);
1711 }
1712 
1713 static void print_rdev(mdk_rdev_t *rdev, int major_version)
1714 {
1715 	char b[BDEVNAME_SIZE];
1716 	printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
1717 		bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
1718 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
1719 	        rdev->desc_nr);
1720 	if (rdev->sb_loaded) {
1721 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
1722 		switch (major_version) {
1723 		case 0:
1724 			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
1725 			break;
1726 		case 1:
1727 			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
1728 			break;
1729 		}
1730 	} else
1731 		printk(KERN_INFO "md: no rdev superblock!\n");
1732 }
1733 
1734 static void md_print_devices(void)
1735 {
1736 	struct list_head *tmp;
1737 	mdk_rdev_t *rdev;
1738 	mddev_t *mddev;
1739 	char b[BDEVNAME_SIZE];
1740 
1741 	printk("\n");
1742 	printk("md:	**********************************\n");
1743 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
1744 	printk("md:	**********************************\n");
1745 	for_each_mddev(mddev, tmp) {
1746 
1747 		if (mddev->bitmap)
1748 			bitmap_print_sb(mddev->bitmap);
1749 		else
1750 			printk("%s: ", mdname(mddev));
1751 		list_for_each_entry(rdev, &mddev->disks, same_set)
1752 			printk("<%s>", bdevname(rdev->bdev,b));
1753 		printk("\n");
1754 
1755 		list_for_each_entry(rdev, &mddev->disks, same_set)
1756 			print_rdev(rdev, mddev->major_version);
1757 	}
1758 	printk("md:	**********************************\n");
1759 	printk("\n");
1760 }
1761 
1762 
1763 static void sync_sbs(mddev_t * mddev, int nospares)
1764 {
1765 	/* Update each superblock (in-memory image), but
1766 	 * if we are allowed to, skip spares which already
1767 	 * have the right event counter, or have one earlier
1768 	 * (which would mean they aren't being marked as dirty
1769 	 * with the rest of the array)
1770 	 */
1771 	mdk_rdev_t *rdev;
1772 
1773 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1774 		if (rdev->sb_events == mddev->events ||
1775 		    (nospares &&
1776 		     rdev->raid_disk < 0 &&
1777 		     (rdev->sb_events&1)==0 &&
1778 		     rdev->sb_events+1 == mddev->events)) {
1779 			/* Don't update this superblock */
1780 			rdev->sb_loaded = 2;
1781 		} else {
1782 			super_types[mddev->major_version].
1783 				sync_super(mddev, rdev);
1784 			rdev->sb_loaded = 1;
1785 		}
1786 	}
1787 }
1788 
1789 static void md_update_sb(mddev_t * mddev, int force_change)
1790 {
1791 	mdk_rdev_t *rdev;
1792 	int sync_req;
1793 	int nospares = 0;
1794 
1795 	if (mddev->external)
1796 		return;
1797 repeat:
1798 	spin_lock_irq(&mddev->write_lock);
1799 
1800 	set_bit(MD_CHANGE_PENDING, &mddev->flags);
1801 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
1802 		force_change = 1;
1803 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
1804 		/* just a clean<-> dirty transition, possibly leave spares alone,
1805 		 * though if events isn't the right even/odd, we will have to do
1806 		 * spares after all
1807 		 */
1808 		nospares = 1;
1809 	if (force_change)
1810 		nospares = 0;
1811 	if (mddev->degraded)
1812 		/* If the array is degraded, then skipping spares is both
1813 		 * dangerous and fairly pointless.
1814 		 * Dangerous because a device that was removed from the array
1815 		 * might have a event_count that still looks up-to-date,
1816 		 * so it can be re-added without a resync.
1817 		 * Pointless because if there are any spares to skip,
1818 		 * then a recovery will happen and soon that array won't
1819 		 * be degraded any more and the spare can go back to sleep then.
1820 		 */
1821 		nospares = 0;
1822 
1823 	sync_req = mddev->in_sync;
1824 	mddev->utime = get_seconds();
1825 
1826 	/* If this is just a dirty<->clean transition, and the array is clean
1827 	 * and 'events' is odd, we can roll back to the previous clean state */
1828 	if (nospares
1829 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
1830 	    && (mddev->events & 1)
1831 	    && mddev->events != 1)
1832 		mddev->events--;
1833 	else {
1834 		/* otherwise we have to go forward and ... */
1835 		mddev->events ++;
1836 		if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
1837 			/* .. if the array isn't clean, insist on an odd 'events' */
1838 			if ((mddev->events&1)==0) {
1839 				mddev->events++;
1840 				nospares = 0;
1841 			}
1842 		} else {
1843 			/* otherwise insist on an even 'events' (for clean states) */
1844 			if ((mddev->events&1)) {
1845 				mddev->events++;
1846 				nospares = 0;
1847 			}
1848 		}
1849 	}
1850 
1851 	if (!mddev->events) {
1852 		/*
1853 		 * oops, this 64-bit counter should never wrap.
1854 		 * Either we are in around ~1 trillion A.C., assuming
1855 		 * 1 reboot per second, or we have a bug:
1856 		 */
1857 		MD_BUG();
1858 		mddev->events --;
1859 	}
1860 
1861 	/*
1862 	 * do not write anything to disk if using
1863 	 * nonpersistent superblocks
1864 	 */
1865 	if (!mddev->persistent) {
1866 		if (!mddev->external)
1867 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
1868 
1869 		spin_unlock_irq(&mddev->write_lock);
1870 		wake_up(&mddev->sb_wait);
1871 		return;
1872 	}
1873 	sync_sbs(mddev, nospares);
1874 	spin_unlock_irq(&mddev->write_lock);
1875 
1876 	dprintk(KERN_INFO
1877 		"md: updating %s RAID superblock on device (in sync %d)\n",
1878 		mdname(mddev),mddev->in_sync);
1879 
1880 	bitmap_update_sb(mddev->bitmap);
1881 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1882 		char b[BDEVNAME_SIZE];
1883 		dprintk(KERN_INFO "md: ");
1884 		if (rdev->sb_loaded != 1)
1885 			continue; /* no noise on spare devices */
1886 		if (test_bit(Faulty, &rdev->flags))
1887 			dprintk("(skipping faulty ");
1888 
1889 		dprintk("%s ", bdevname(rdev->bdev,b));
1890 		if (!test_bit(Faulty, &rdev->flags)) {
1891 			md_super_write(mddev,rdev,
1892 				       rdev->sb_start, rdev->sb_size,
1893 				       rdev->sb_page);
1894 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1895 				bdevname(rdev->bdev,b),
1896 				(unsigned long long)rdev->sb_start);
1897 			rdev->sb_events = mddev->events;
1898 
1899 		} else
1900 			dprintk(")\n");
1901 		if (mddev->level == LEVEL_MULTIPATH)
1902 			/* only need to write one superblock... */
1903 			break;
1904 	}
1905 	md_super_wait(mddev);
1906 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
1907 
1908 	spin_lock_irq(&mddev->write_lock);
1909 	if (mddev->in_sync != sync_req ||
1910 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
1911 		/* have to write it out again */
1912 		spin_unlock_irq(&mddev->write_lock);
1913 		goto repeat;
1914 	}
1915 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
1916 	spin_unlock_irq(&mddev->write_lock);
1917 	wake_up(&mddev->sb_wait);
1918 
1919 }
1920 
1921 /* words written to sysfs files may, or may not, be \n terminated.
1922  * We want to accept with case. For this we use cmd_match.
1923  */
1924 static int cmd_match(const char *cmd, const char *str)
1925 {
1926 	/* See if cmd, written into a sysfs file, matches
1927 	 * str.  They must either be the same, or cmd can
1928 	 * have a trailing newline
1929 	 */
1930 	while (*cmd && *str && *cmd == *str) {
1931 		cmd++;
1932 		str++;
1933 	}
1934 	if (*cmd == '\n')
1935 		cmd++;
1936 	if (*str || *cmd)
1937 		return 0;
1938 	return 1;
1939 }
1940 
1941 struct rdev_sysfs_entry {
1942 	struct attribute attr;
1943 	ssize_t (*show)(mdk_rdev_t *, char *);
1944 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
1945 };
1946 
1947 static ssize_t
1948 state_show(mdk_rdev_t *rdev, char *page)
1949 {
1950 	char *sep = "";
1951 	size_t len = 0;
1952 
1953 	if (test_bit(Faulty, &rdev->flags)) {
1954 		len+= sprintf(page+len, "%sfaulty",sep);
1955 		sep = ",";
1956 	}
1957 	if (test_bit(In_sync, &rdev->flags)) {
1958 		len += sprintf(page+len, "%sin_sync",sep);
1959 		sep = ",";
1960 	}
1961 	if (test_bit(WriteMostly, &rdev->flags)) {
1962 		len += sprintf(page+len, "%swrite_mostly",sep);
1963 		sep = ",";
1964 	}
1965 	if (test_bit(Blocked, &rdev->flags)) {
1966 		len += sprintf(page+len, "%sblocked", sep);
1967 		sep = ",";
1968 	}
1969 	if (!test_bit(Faulty, &rdev->flags) &&
1970 	    !test_bit(In_sync, &rdev->flags)) {
1971 		len += sprintf(page+len, "%sspare", sep);
1972 		sep = ",";
1973 	}
1974 	return len+sprintf(page+len, "\n");
1975 }
1976 
1977 static ssize_t
1978 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
1979 {
1980 	/* can write
1981 	 *  faulty  - simulates and error
1982 	 *  remove  - disconnects the device
1983 	 *  writemostly - sets write_mostly
1984 	 *  -writemostly - clears write_mostly
1985 	 *  blocked - sets the Blocked flag
1986 	 *  -blocked - clears the Blocked flag
1987 	 */
1988 	int err = -EINVAL;
1989 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
1990 		md_error(rdev->mddev, rdev);
1991 		err = 0;
1992 	} else if (cmd_match(buf, "remove")) {
1993 		if (rdev->raid_disk >= 0)
1994 			err = -EBUSY;
1995 		else {
1996 			mddev_t *mddev = rdev->mddev;
1997 			kick_rdev_from_array(rdev);
1998 			if (mddev->pers)
1999 				md_update_sb(mddev, 1);
2000 			md_new_event(mddev);
2001 			err = 0;
2002 		}
2003 	} else if (cmd_match(buf, "writemostly")) {
2004 		set_bit(WriteMostly, &rdev->flags);
2005 		err = 0;
2006 	} else if (cmd_match(buf, "-writemostly")) {
2007 		clear_bit(WriteMostly, &rdev->flags);
2008 		err = 0;
2009 	} else if (cmd_match(buf, "blocked")) {
2010 		set_bit(Blocked, &rdev->flags);
2011 		err = 0;
2012 	} else if (cmd_match(buf, "-blocked")) {
2013 		clear_bit(Blocked, &rdev->flags);
2014 		wake_up(&rdev->blocked_wait);
2015 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2016 		md_wakeup_thread(rdev->mddev->thread);
2017 
2018 		err = 0;
2019 	}
2020 	if (!err && rdev->sysfs_state)
2021 		sysfs_notify_dirent(rdev->sysfs_state);
2022 	return err ? err : len;
2023 }
2024 static struct rdev_sysfs_entry rdev_state =
2025 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2026 
2027 static ssize_t
2028 errors_show(mdk_rdev_t *rdev, char *page)
2029 {
2030 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2031 }
2032 
2033 static ssize_t
2034 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2035 {
2036 	char *e;
2037 	unsigned long n = simple_strtoul(buf, &e, 10);
2038 	if (*buf && (*e == 0 || *e == '\n')) {
2039 		atomic_set(&rdev->corrected_errors, n);
2040 		return len;
2041 	}
2042 	return -EINVAL;
2043 }
2044 static struct rdev_sysfs_entry rdev_errors =
2045 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2046 
2047 static ssize_t
2048 slot_show(mdk_rdev_t *rdev, char *page)
2049 {
2050 	if (rdev->raid_disk < 0)
2051 		return sprintf(page, "none\n");
2052 	else
2053 		return sprintf(page, "%d\n", rdev->raid_disk);
2054 }
2055 
2056 static ssize_t
2057 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2058 {
2059 	char *e;
2060 	int err;
2061 	char nm[20];
2062 	int slot = simple_strtoul(buf, &e, 10);
2063 	if (strncmp(buf, "none", 4)==0)
2064 		slot = -1;
2065 	else if (e==buf || (*e && *e!= '\n'))
2066 		return -EINVAL;
2067 	if (rdev->mddev->pers && slot == -1) {
2068 		/* Setting 'slot' on an active array requires also
2069 		 * updating the 'rd%d' link, and communicating
2070 		 * with the personality with ->hot_*_disk.
2071 		 * For now we only support removing
2072 		 * failed/spare devices.  This normally happens automatically,
2073 		 * but not when the metadata is externally managed.
2074 		 */
2075 		if (rdev->raid_disk == -1)
2076 			return -EEXIST;
2077 		/* personality does all needed checks */
2078 		if (rdev->mddev->pers->hot_add_disk == NULL)
2079 			return -EINVAL;
2080 		err = rdev->mddev->pers->
2081 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2082 		if (err)
2083 			return err;
2084 		sprintf(nm, "rd%d", rdev->raid_disk);
2085 		sysfs_remove_link(&rdev->mddev->kobj, nm);
2086 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2087 		md_wakeup_thread(rdev->mddev->thread);
2088 	} else if (rdev->mddev->pers) {
2089 		mdk_rdev_t *rdev2;
2090 		/* Activating a spare .. or possibly reactivating
2091 		 * if we every get bitmaps working here.
2092 		 */
2093 
2094 		if (rdev->raid_disk != -1)
2095 			return -EBUSY;
2096 
2097 		if (rdev->mddev->pers->hot_add_disk == NULL)
2098 			return -EINVAL;
2099 
2100 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2101 			if (rdev2->raid_disk == slot)
2102 				return -EEXIST;
2103 
2104 		rdev->raid_disk = slot;
2105 		if (test_bit(In_sync, &rdev->flags))
2106 			rdev->saved_raid_disk = slot;
2107 		else
2108 			rdev->saved_raid_disk = -1;
2109 		err = rdev->mddev->pers->
2110 			hot_add_disk(rdev->mddev, rdev);
2111 		if (err) {
2112 			rdev->raid_disk = -1;
2113 			return err;
2114 		} else
2115 			sysfs_notify_dirent(rdev->sysfs_state);
2116 		sprintf(nm, "rd%d", rdev->raid_disk);
2117 		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
2118 			printk(KERN_WARNING
2119 			       "md: cannot register "
2120 			       "%s for %s\n",
2121 			       nm, mdname(rdev->mddev));
2122 
2123 		/* don't wakeup anyone, leave that to userspace. */
2124 	} else {
2125 		if (slot >= rdev->mddev->raid_disks)
2126 			return -ENOSPC;
2127 		rdev->raid_disk = slot;
2128 		/* assume it is working */
2129 		clear_bit(Faulty, &rdev->flags);
2130 		clear_bit(WriteMostly, &rdev->flags);
2131 		set_bit(In_sync, &rdev->flags);
2132 		sysfs_notify_dirent(rdev->sysfs_state);
2133 	}
2134 	return len;
2135 }
2136 
2137 
2138 static struct rdev_sysfs_entry rdev_slot =
2139 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2140 
2141 static ssize_t
2142 offset_show(mdk_rdev_t *rdev, char *page)
2143 {
2144 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2145 }
2146 
2147 static ssize_t
2148 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2149 {
2150 	char *e;
2151 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2152 	if (e==buf || (*e && *e != '\n'))
2153 		return -EINVAL;
2154 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2155 		return -EBUSY;
2156 	if (rdev->size && rdev->mddev->external)
2157 		/* Must set offset before size, so overlap checks
2158 		 * can be sane */
2159 		return -EBUSY;
2160 	rdev->data_offset = offset;
2161 	return len;
2162 }
2163 
2164 static struct rdev_sysfs_entry rdev_offset =
2165 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2166 
2167 static ssize_t
2168 rdev_size_show(mdk_rdev_t *rdev, char *page)
2169 {
2170 	return sprintf(page, "%llu\n", (unsigned long long)rdev->size);
2171 }
2172 
2173 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2174 {
2175 	/* check if two start/length pairs overlap */
2176 	if (s1+l1 <= s2)
2177 		return 0;
2178 	if (s2+l2 <= s1)
2179 		return 0;
2180 	return 1;
2181 }
2182 
2183 static ssize_t
2184 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2185 {
2186 	unsigned long long size;
2187 	unsigned long long oldsize = rdev->size;
2188 	mddev_t *my_mddev = rdev->mddev;
2189 
2190 	if (strict_strtoull(buf, 10, &size) < 0)
2191 		return -EINVAL;
2192 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2193 		if (my_mddev->persistent) {
2194 			size = super_types[my_mddev->major_version].
2195 				rdev_size_change(rdev, size * 2);
2196 			if (!size)
2197 				return -EBUSY;
2198 		} else if (!size) {
2199 			size = (rdev->bdev->bd_inode->i_size >> 10);
2200 			size -= rdev->data_offset/2;
2201 		}
2202 	}
2203 	if (size < my_mddev->size)
2204 		return -EINVAL; /* component must fit device */
2205 
2206 	rdev->size = size;
2207 	if (size > oldsize && my_mddev->external) {
2208 		/* need to check that all other rdevs with the same ->bdev
2209 		 * do not overlap.  We need to unlock the mddev to avoid
2210 		 * a deadlock.  We have already changed rdev->size, and if
2211 		 * we have to change it back, we will have the lock again.
2212 		 */
2213 		mddev_t *mddev;
2214 		int overlap = 0;
2215 		struct list_head *tmp;
2216 
2217 		mddev_unlock(my_mddev);
2218 		for_each_mddev(mddev, tmp) {
2219 			mdk_rdev_t *rdev2;
2220 
2221 			mddev_lock(mddev);
2222 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2223 				if (test_bit(AllReserved, &rdev2->flags) ||
2224 				    (rdev->bdev == rdev2->bdev &&
2225 				     rdev != rdev2 &&
2226 				     overlaps(rdev->data_offset, rdev->size * 2,
2227 					      rdev2->data_offset,
2228 					      rdev2->size * 2))) {
2229 					overlap = 1;
2230 					break;
2231 				}
2232 			mddev_unlock(mddev);
2233 			if (overlap) {
2234 				mddev_put(mddev);
2235 				break;
2236 			}
2237 		}
2238 		mddev_lock(my_mddev);
2239 		if (overlap) {
2240 			/* Someone else could have slipped in a size
2241 			 * change here, but doing so is just silly.
2242 			 * We put oldsize back because we *know* it is
2243 			 * safe, and trust userspace not to race with
2244 			 * itself
2245 			 */
2246 			rdev->size = oldsize;
2247 			return -EBUSY;
2248 		}
2249 	}
2250 	return len;
2251 }
2252 
2253 static struct rdev_sysfs_entry rdev_size =
2254 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2255 
2256 static struct attribute *rdev_default_attrs[] = {
2257 	&rdev_state.attr,
2258 	&rdev_errors.attr,
2259 	&rdev_slot.attr,
2260 	&rdev_offset.attr,
2261 	&rdev_size.attr,
2262 	NULL,
2263 };
2264 static ssize_t
2265 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2266 {
2267 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2268 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2269 	mddev_t *mddev = rdev->mddev;
2270 	ssize_t rv;
2271 
2272 	if (!entry->show)
2273 		return -EIO;
2274 
2275 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2276 	if (!rv) {
2277 		if (rdev->mddev == NULL)
2278 			rv = -EBUSY;
2279 		else
2280 			rv = entry->show(rdev, page);
2281 		mddev_unlock(mddev);
2282 	}
2283 	return rv;
2284 }
2285 
2286 static ssize_t
2287 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2288 	      const char *page, size_t length)
2289 {
2290 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2291 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2292 	ssize_t rv;
2293 	mddev_t *mddev = rdev->mddev;
2294 
2295 	if (!entry->store)
2296 		return -EIO;
2297 	if (!capable(CAP_SYS_ADMIN))
2298 		return -EACCES;
2299 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2300 	if (!rv) {
2301 		if (rdev->mddev == NULL)
2302 			rv = -EBUSY;
2303 		else
2304 			rv = entry->store(rdev, page, length);
2305 		mddev_unlock(mddev);
2306 	}
2307 	return rv;
2308 }
2309 
2310 static void rdev_free(struct kobject *ko)
2311 {
2312 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2313 	kfree(rdev);
2314 }
2315 static struct sysfs_ops rdev_sysfs_ops = {
2316 	.show		= rdev_attr_show,
2317 	.store		= rdev_attr_store,
2318 };
2319 static struct kobj_type rdev_ktype = {
2320 	.release	= rdev_free,
2321 	.sysfs_ops	= &rdev_sysfs_ops,
2322 	.default_attrs	= rdev_default_attrs,
2323 };
2324 
2325 /*
2326  * Import a device. If 'super_format' >= 0, then sanity check the superblock
2327  *
2328  * mark the device faulty if:
2329  *
2330  *   - the device is nonexistent (zero size)
2331  *   - the device has no valid superblock
2332  *
2333  * a faulty rdev _never_ has rdev->sb set.
2334  */
2335 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
2336 {
2337 	char b[BDEVNAME_SIZE];
2338 	int err;
2339 	mdk_rdev_t *rdev;
2340 	sector_t size;
2341 
2342 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
2343 	if (!rdev) {
2344 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
2345 		return ERR_PTR(-ENOMEM);
2346 	}
2347 
2348 	if ((err = alloc_disk_sb(rdev)))
2349 		goto abort_free;
2350 
2351 	err = lock_rdev(rdev, newdev, super_format == -2);
2352 	if (err)
2353 		goto abort_free;
2354 
2355 	kobject_init(&rdev->kobj, &rdev_ktype);
2356 
2357 	rdev->desc_nr = -1;
2358 	rdev->saved_raid_disk = -1;
2359 	rdev->raid_disk = -1;
2360 	rdev->flags = 0;
2361 	rdev->data_offset = 0;
2362 	rdev->sb_events = 0;
2363 	atomic_set(&rdev->nr_pending, 0);
2364 	atomic_set(&rdev->read_errors, 0);
2365 	atomic_set(&rdev->corrected_errors, 0);
2366 
2367 	size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2368 	if (!size) {
2369 		printk(KERN_WARNING
2370 			"md: %s has zero or unknown size, marking faulty!\n",
2371 			bdevname(rdev->bdev,b));
2372 		err = -EINVAL;
2373 		goto abort_free;
2374 	}
2375 
2376 	if (super_format >= 0) {
2377 		err = super_types[super_format].
2378 			load_super(rdev, NULL, super_minor);
2379 		if (err == -EINVAL) {
2380 			printk(KERN_WARNING
2381 				"md: %s does not have a valid v%d.%d "
2382 			       "superblock, not importing!\n",
2383 				bdevname(rdev->bdev,b),
2384 			       super_format, super_minor);
2385 			goto abort_free;
2386 		}
2387 		if (err < 0) {
2388 			printk(KERN_WARNING
2389 				"md: could not read %s's sb, not importing!\n",
2390 				bdevname(rdev->bdev,b));
2391 			goto abort_free;
2392 		}
2393 	}
2394 
2395 	INIT_LIST_HEAD(&rdev->same_set);
2396 	init_waitqueue_head(&rdev->blocked_wait);
2397 
2398 	return rdev;
2399 
2400 abort_free:
2401 	if (rdev->sb_page) {
2402 		if (rdev->bdev)
2403 			unlock_rdev(rdev);
2404 		free_disk_sb(rdev);
2405 	}
2406 	kfree(rdev);
2407 	return ERR_PTR(err);
2408 }
2409 
2410 /*
2411  * Check a full RAID array for plausibility
2412  */
2413 
2414 
2415 static void analyze_sbs(mddev_t * mddev)
2416 {
2417 	int i;
2418 	mdk_rdev_t *rdev, *freshest, *tmp;
2419 	char b[BDEVNAME_SIZE];
2420 
2421 	freshest = NULL;
2422 	rdev_for_each(rdev, tmp, mddev)
2423 		switch (super_types[mddev->major_version].
2424 			load_super(rdev, freshest, mddev->minor_version)) {
2425 		case 1:
2426 			freshest = rdev;
2427 			break;
2428 		case 0:
2429 			break;
2430 		default:
2431 			printk( KERN_ERR \
2432 				"md: fatal superblock inconsistency in %s"
2433 				" -- removing from array\n",
2434 				bdevname(rdev->bdev,b));
2435 			kick_rdev_from_array(rdev);
2436 		}
2437 
2438 
2439 	super_types[mddev->major_version].
2440 		validate_super(mddev, freshest);
2441 
2442 	i = 0;
2443 	rdev_for_each(rdev, tmp, mddev) {
2444 		if (rdev->desc_nr >= mddev->max_disks ||
2445 		    i > mddev->max_disks) {
2446 			printk(KERN_WARNING
2447 			       "md: %s: %s: only %d devices permitted\n",
2448 			       mdname(mddev), bdevname(rdev->bdev, b),
2449 			       mddev->max_disks);
2450 			kick_rdev_from_array(rdev);
2451 			continue;
2452 		}
2453 		if (rdev != freshest)
2454 			if (super_types[mddev->major_version].
2455 			    validate_super(mddev, rdev)) {
2456 				printk(KERN_WARNING "md: kicking non-fresh %s"
2457 					" from array!\n",
2458 					bdevname(rdev->bdev,b));
2459 				kick_rdev_from_array(rdev);
2460 				continue;
2461 			}
2462 		if (mddev->level == LEVEL_MULTIPATH) {
2463 			rdev->desc_nr = i++;
2464 			rdev->raid_disk = rdev->desc_nr;
2465 			set_bit(In_sync, &rdev->flags);
2466 		} else if (rdev->raid_disk >= mddev->raid_disks) {
2467 			rdev->raid_disk = -1;
2468 			clear_bit(In_sync, &rdev->flags);
2469 		}
2470 	}
2471 
2472 
2473 
2474 	if (mddev->recovery_cp != MaxSector &&
2475 	    mddev->level >= 1)
2476 		printk(KERN_ERR "md: %s: raid array is not clean"
2477 		       " -- starting background reconstruction\n",
2478 		       mdname(mddev));
2479 
2480 }
2481 
2482 static void md_safemode_timeout(unsigned long data);
2483 
2484 static ssize_t
2485 safe_delay_show(mddev_t *mddev, char *page)
2486 {
2487 	int msec = (mddev->safemode_delay*1000)/HZ;
2488 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
2489 }
2490 static ssize_t
2491 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
2492 {
2493 	int scale=1;
2494 	int dot=0;
2495 	int i;
2496 	unsigned long msec;
2497 	char buf[30];
2498 
2499 	/* remove a period, and count digits after it */
2500 	if (len >= sizeof(buf))
2501 		return -EINVAL;
2502 	strlcpy(buf, cbuf, sizeof(buf));
2503 	for (i=0; i<len; i++) {
2504 		if (dot) {
2505 			if (isdigit(buf[i])) {
2506 				buf[i-1] = buf[i];
2507 				scale *= 10;
2508 			}
2509 			buf[i] = 0;
2510 		} else if (buf[i] == '.') {
2511 			dot=1;
2512 			buf[i] = 0;
2513 		}
2514 	}
2515 	if (strict_strtoul(buf, 10, &msec) < 0)
2516 		return -EINVAL;
2517 	msec = (msec * 1000) / scale;
2518 	if (msec == 0)
2519 		mddev->safemode_delay = 0;
2520 	else {
2521 		unsigned long old_delay = mddev->safemode_delay;
2522 		mddev->safemode_delay = (msec*HZ)/1000;
2523 		if (mddev->safemode_delay == 0)
2524 			mddev->safemode_delay = 1;
2525 		if (mddev->safemode_delay < old_delay)
2526 			md_safemode_timeout((unsigned long)mddev);
2527 	}
2528 	return len;
2529 }
2530 static struct md_sysfs_entry md_safe_delay =
2531 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
2532 
2533 static ssize_t
2534 level_show(mddev_t *mddev, char *page)
2535 {
2536 	struct mdk_personality *p = mddev->pers;
2537 	if (p)
2538 		return sprintf(page, "%s\n", p->name);
2539 	else if (mddev->clevel[0])
2540 		return sprintf(page, "%s\n", mddev->clevel);
2541 	else if (mddev->level != LEVEL_NONE)
2542 		return sprintf(page, "%d\n", mddev->level);
2543 	else
2544 		return 0;
2545 }
2546 
2547 static ssize_t
2548 level_store(mddev_t *mddev, const char *buf, size_t len)
2549 {
2550 	ssize_t rv = len;
2551 	if (mddev->pers)
2552 		return -EBUSY;
2553 	if (len == 0)
2554 		return 0;
2555 	if (len >= sizeof(mddev->clevel))
2556 		return -ENOSPC;
2557 	strncpy(mddev->clevel, buf, len);
2558 	if (mddev->clevel[len-1] == '\n')
2559 		len--;
2560 	mddev->clevel[len] = 0;
2561 	mddev->level = LEVEL_NONE;
2562 	return rv;
2563 }
2564 
2565 static struct md_sysfs_entry md_level =
2566 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
2567 
2568 
2569 static ssize_t
2570 layout_show(mddev_t *mddev, char *page)
2571 {
2572 	/* just a number, not meaningful for all levels */
2573 	if (mddev->reshape_position != MaxSector &&
2574 	    mddev->layout != mddev->new_layout)
2575 		return sprintf(page, "%d (%d)\n",
2576 			       mddev->new_layout, mddev->layout);
2577 	return sprintf(page, "%d\n", mddev->layout);
2578 }
2579 
2580 static ssize_t
2581 layout_store(mddev_t *mddev, const char *buf, size_t len)
2582 {
2583 	char *e;
2584 	unsigned long n = simple_strtoul(buf, &e, 10);
2585 
2586 	if (!*buf || (*e && *e != '\n'))
2587 		return -EINVAL;
2588 
2589 	if (mddev->pers)
2590 		return -EBUSY;
2591 	if (mddev->reshape_position != MaxSector)
2592 		mddev->new_layout = n;
2593 	else
2594 		mddev->layout = n;
2595 	return len;
2596 }
2597 static struct md_sysfs_entry md_layout =
2598 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
2599 
2600 
2601 static ssize_t
2602 raid_disks_show(mddev_t *mddev, char *page)
2603 {
2604 	if (mddev->raid_disks == 0)
2605 		return 0;
2606 	if (mddev->reshape_position != MaxSector &&
2607 	    mddev->delta_disks != 0)
2608 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
2609 			       mddev->raid_disks - mddev->delta_disks);
2610 	return sprintf(page, "%d\n", mddev->raid_disks);
2611 }
2612 
2613 static int update_raid_disks(mddev_t *mddev, int raid_disks);
2614 
2615 static ssize_t
2616 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
2617 {
2618 	char *e;
2619 	int rv = 0;
2620 	unsigned long n = simple_strtoul(buf, &e, 10);
2621 
2622 	if (!*buf || (*e && *e != '\n'))
2623 		return -EINVAL;
2624 
2625 	if (mddev->pers)
2626 		rv = update_raid_disks(mddev, n);
2627 	else if (mddev->reshape_position != MaxSector) {
2628 		int olddisks = mddev->raid_disks - mddev->delta_disks;
2629 		mddev->delta_disks = n - olddisks;
2630 		mddev->raid_disks = n;
2631 	} else
2632 		mddev->raid_disks = n;
2633 	return rv ? rv : len;
2634 }
2635 static struct md_sysfs_entry md_raid_disks =
2636 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
2637 
2638 static ssize_t
2639 chunk_size_show(mddev_t *mddev, char *page)
2640 {
2641 	if (mddev->reshape_position != MaxSector &&
2642 	    mddev->chunk_size != mddev->new_chunk)
2643 		return sprintf(page, "%d (%d)\n", mddev->new_chunk,
2644 			       mddev->chunk_size);
2645 	return sprintf(page, "%d\n", mddev->chunk_size);
2646 }
2647 
2648 static ssize_t
2649 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2650 {
2651 	/* can only set chunk_size if array is not yet active */
2652 	char *e;
2653 	unsigned long n = simple_strtoul(buf, &e, 10);
2654 
2655 	if (!*buf || (*e && *e != '\n'))
2656 		return -EINVAL;
2657 
2658 	if (mddev->pers)
2659 		return -EBUSY;
2660 	else if (mddev->reshape_position != MaxSector)
2661 		mddev->new_chunk = n;
2662 	else
2663 		mddev->chunk_size = n;
2664 	return len;
2665 }
2666 static struct md_sysfs_entry md_chunk_size =
2667 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
2668 
2669 static ssize_t
2670 resync_start_show(mddev_t *mddev, char *page)
2671 {
2672 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
2673 }
2674 
2675 static ssize_t
2676 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
2677 {
2678 	char *e;
2679 	unsigned long long n = simple_strtoull(buf, &e, 10);
2680 
2681 	if (mddev->pers)
2682 		return -EBUSY;
2683 	if (!*buf || (*e && *e != '\n'))
2684 		return -EINVAL;
2685 
2686 	mddev->recovery_cp = n;
2687 	return len;
2688 }
2689 static struct md_sysfs_entry md_resync_start =
2690 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
2691 
2692 /*
2693  * The array state can be:
2694  *
2695  * clear
2696  *     No devices, no size, no level
2697  *     Equivalent to STOP_ARRAY ioctl
2698  * inactive
2699  *     May have some settings, but array is not active
2700  *        all IO results in error
2701  *     When written, doesn't tear down array, but just stops it
2702  * suspended (not supported yet)
2703  *     All IO requests will block. The array can be reconfigured.
2704  *     Writing this, if accepted, will block until array is quiescent
2705  * readonly
2706  *     no resync can happen.  no superblocks get written.
2707  *     write requests fail
2708  * read-auto
2709  *     like readonly, but behaves like 'clean' on a write request.
2710  *
2711  * clean - no pending writes, but otherwise active.
2712  *     When written to inactive array, starts without resync
2713  *     If a write request arrives then
2714  *       if metadata is known, mark 'dirty' and switch to 'active'.
2715  *       if not known, block and switch to write-pending
2716  *     If written to an active array that has pending writes, then fails.
2717  * active
2718  *     fully active: IO and resync can be happening.
2719  *     When written to inactive array, starts with resync
2720  *
2721  * write-pending
2722  *     clean, but writes are blocked waiting for 'active' to be written.
2723  *
2724  * active-idle
2725  *     like active, but no writes have been seen for a while (100msec).
2726  *
2727  */
2728 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
2729 		   write_pending, active_idle, bad_word};
2730 static char *array_states[] = {
2731 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
2732 	"write-pending", "active-idle", NULL };
2733 
2734 static int match_word(const char *word, char **list)
2735 {
2736 	int n;
2737 	for (n=0; list[n]; n++)
2738 		if (cmd_match(word, list[n]))
2739 			break;
2740 	return n;
2741 }
2742 
2743 static ssize_t
2744 array_state_show(mddev_t *mddev, char *page)
2745 {
2746 	enum array_state st = inactive;
2747 
2748 	if (mddev->pers)
2749 		switch(mddev->ro) {
2750 		case 1:
2751 			st = readonly;
2752 			break;
2753 		case 2:
2754 			st = read_auto;
2755 			break;
2756 		case 0:
2757 			if (mddev->in_sync)
2758 				st = clean;
2759 			else if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
2760 				st = write_pending;
2761 			else if (mddev->safemode)
2762 				st = active_idle;
2763 			else
2764 				st = active;
2765 		}
2766 	else {
2767 		if (list_empty(&mddev->disks) &&
2768 		    mddev->raid_disks == 0 &&
2769 		    mddev->size == 0)
2770 			st = clear;
2771 		else
2772 			st = inactive;
2773 	}
2774 	return sprintf(page, "%s\n", array_states[st]);
2775 }
2776 
2777 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
2778 static int do_md_run(mddev_t * mddev);
2779 static int restart_array(mddev_t *mddev);
2780 
2781 static ssize_t
2782 array_state_store(mddev_t *mddev, const char *buf, size_t len)
2783 {
2784 	int err = -EINVAL;
2785 	enum array_state st = match_word(buf, array_states);
2786 	switch(st) {
2787 	case bad_word:
2788 		break;
2789 	case clear:
2790 		/* stopping an active array */
2791 		if (atomic_read(&mddev->openers) > 0)
2792 			return -EBUSY;
2793 		err = do_md_stop(mddev, 0, 0);
2794 		break;
2795 	case inactive:
2796 		/* stopping an active array */
2797 		if (mddev->pers) {
2798 			if (atomic_read(&mddev->openers) > 0)
2799 				return -EBUSY;
2800 			err = do_md_stop(mddev, 2, 0);
2801 		} else
2802 			err = 0; /* already inactive */
2803 		break;
2804 	case suspended:
2805 		break; /* not supported yet */
2806 	case readonly:
2807 		if (mddev->pers)
2808 			err = do_md_stop(mddev, 1, 0);
2809 		else {
2810 			mddev->ro = 1;
2811 			set_disk_ro(mddev->gendisk, 1);
2812 			err = do_md_run(mddev);
2813 		}
2814 		break;
2815 	case read_auto:
2816 		if (mddev->pers) {
2817 			if (mddev->ro == 0)
2818 				err = do_md_stop(mddev, 1, 0);
2819 			else if (mddev->ro == 1)
2820 				err = restart_array(mddev);
2821 			if (err == 0) {
2822 				mddev->ro = 2;
2823 				set_disk_ro(mddev->gendisk, 0);
2824 			}
2825 		} else {
2826 			mddev->ro = 2;
2827 			err = do_md_run(mddev);
2828 		}
2829 		break;
2830 	case clean:
2831 		if (mddev->pers) {
2832 			restart_array(mddev);
2833 			spin_lock_irq(&mddev->write_lock);
2834 			if (atomic_read(&mddev->writes_pending) == 0) {
2835 				if (mddev->in_sync == 0) {
2836 					mddev->in_sync = 1;
2837 					if (mddev->safemode == 1)
2838 						mddev->safemode = 0;
2839 					if (mddev->persistent)
2840 						set_bit(MD_CHANGE_CLEAN,
2841 							&mddev->flags);
2842 				}
2843 				err = 0;
2844 			} else
2845 				err = -EBUSY;
2846 			spin_unlock_irq(&mddev->write_lock);
2847 		} else {
2848 			mddev->ro = 0;
2849 			mddev->recovery_cp = MaxSector;
2850 			err = do_md_run(mddev);
2851 		}
2852 		break;
2853 	case active:
2854 		if (mddev->pers) {
2855 			restart_array(mddev);
2856 			if (mddev->external)
2857 				clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2858 			wake_up(&mddev->sb_wait);
2859 			err = 0;
2860 		} else {
2861 			mddev->ro = 0;
2862 			set_disk_ro(mddev->gendisk, 0);
2863 			err = do_md_run(mddev);
2864 		}
2865 		break;
2866 	case write_pending:
2867 	case active_idle:
2868 		/* these cannot be set */
2869 		break;
2870 	}
2871 	if (err)
2872 		return err;
2873 	else {
2874 		sysfs_notify_dirent(mddev->sysfs_state);
2875 		return len;
2876 	}
2877 }
2878 static struct md_sysfs_entry md_array_state =
2879 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
2880 
2881 static ssize_t
2882 null_show(mddev_t *mddev, char *page)
2883 {
2884 	return -EINVAL;
2885 }
2886 
2887 static ssize_t
2888 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
2889 {
2890 	/* buf must be %d:%d\n? giving major and minor numbers */
2891 	/* The new device is added to the array.
2892 	 * If the array has a persistent superblock, we read the
2893 	 * superblock to initialise info and check validity.
2894 	 * Otherwise, only checking done is that in bind_rdev_to_array,
2895 	 * which mainly checks size.
2896 	 */
2897 	char *e;
2898 	int major = simple_strtoul(buf, &e, 10);
2899 	int minor;
2900 	dev_t dev;
2901 	mdk_rdev_t *rdev;
2902 	int err;
2903 
2904 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
2905 		return -EINVAL;
2906 	minor = simple_strtoul(e+1, &e, 10);
2907 	if (*e && *e != '\n')
2908 		return -EINVAL;
2909 	dev = MKDEV(major, minor);
2910 	if (major != MAJOR(dev) ||
2911 	    minor != MINOR(dev))
2912 		return -EOVERFLOW;
2913 
2914 
2915 	if (mddev->persistent) {
2916 		rdev = md_import_device(dev, mddev->major_version,
2917 					mddev->minor_version);
2918 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
2919 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
2920 						       mdk_rdev_t, same_set);
2921 			err = super_types[mddev->major_version]
2922 				.load_super(rdev, rdev0, mddev->minor_version);
2923 			if (err < 0)
2924 				goto out;
2925 		}
2926 	} else if (mddev->external)
2927 		rdev = md_import_device(dev, -2, -1);
2928 	else
2929 		rdev = md_import_device(dev, -1, -1);
2930 
2931 	if (IS_ERR(rdev))
2932 		return PTR_ERR(rdev);
2933 	err = bind_rdev_to_array(rdev, mddev);
2934  out:
2935 	if (err)
2936 		export_rdev(rdev);
2937 	return err ? err : len;
2938 }
2939 
2940 static struct md_sysfs_entry md_new_device =
2941 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
2942 
2943 static ssize_t
2944 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
2945 {
2946 	char *end;
2947 	unsigned long chunk, end_chunk;
2948 
2949 	if (!mddev->bitmap)
2950 		goto out;
2951 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
2952 	while (*buf) {
2953 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
2954 		if (buf == end) break;
2955 		if (*end == '-') { /* range */
2956 			buf = end + 1;
2957 			end_chunk = simple_strtoul(buf, &end, 0);
2958 			if (buf == end) break;
2959 		}
2960 		if (*end && !isspace(*end)) break;
2961 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
2962 		buf = end;
2963 		while (isspace(*buf)) buf++;
2964 	}
2965 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
2966 out:
2967 	return len;
2968 }
2969 
2970 static struct md_sysfs_entry md_bitmap =
2971 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
2972 
2973 static ssize_t
2974 size_show(mddev_t *mddev, char *page)
2975 {
2976 	return sprintf(page, "%llu\n", (unsigned long long)mddev->size);
2977 }
2978 
2979 static int update_size(mddev_t *mddev, sector_t num_sectors);
2980 
2981 static ssize_t
2982 size_store(mddev_t *mddev, const char *buf, size_t len)
2983 {
2984 	/* If array is inactive, we can reduce the component size, but
2985 	 * not increase it (except from 0).
2986 	 * If array is active, we can try an on-line resize
2987 	 */
2988 	char *e;
2989 	int err = 0;
2990 	unsigned long long size = simple_strtoull(buf, &e, 10);
2991 	if (!*buf || *buf == '\n' ||
2992 	    (*e && *e != '\n'))
2993 		return -EINVAL;
2994 
2995 	if (mddev->pers) {
2996 		err = update_size(mddev, size * 2);
2997 		md_update_sb(mddev, 1);
2998 	} else {
2999 		if (mddev->size == 0 ||
3000 		    mddev->size > size)
3001 			mddev->size = size;
3002 		else
3003 			err = -ENOSPC;
3004 	}
3005 	return err ? err : len;
3006 }
3007 
3008 static struct md_sysfs_entry md_size =
3009 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3010 
3011 
3012 /* Metdata version.
3013  * This is one of
3014  *   'none' for arrays with no metadata (good luck...)
3015  *   'external' for arrays with externally managed metadata,
3016  * or N.M for internally known formats
3017  */
3018 static ssize_t
3019 metadata_show(mddev_t *mddev, char *page)
3020 {
3021 	if (mddev->persistent)
3022 		return sprintf(page, "%d.%d\n",
3023 			       mddev->major_version, mddev->minor_version);
3024 	else if (mddev->external)
3025 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3026 	else
3027 		return sprintf(page, "none\n");
3028 }
3029 
3030 static ssize_t
3031 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3032 {
3033 	int major, minor;
3034 	char *e;
3035 	/* Changing the details of 'external' metadata is
3036 	 * always permitted.  Otherwise there must be
3037 	 * no devices attached to the array.
3038 	 */
3039 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3040 		;
3041 	else if (!list_empty(&mddev->disks))
3042 		return -EBUSY;
3043 
3044 	if (cmd_match(buf, "none")) {
3045 		mddev->persistent = 0;
3046 		mddev->external = 0;
3047 		mddev->major_version = 0;
3048 		mddev->minor_version = 90;
3049 		return len;
3050 	}
3051 	if (strncmp(buf, "external:", 9) == 0) {
3052 		size_t namelen = len-9;
3053 		if (namelen >= sizeof(mddev->metadata_type))
3054 			namelen = sizeof(mddev->metadata_type)-1;
3055 		strncpy(mddev->metadata_type, buf+9, namelen);
3056 		mddev->metadata_type[namelen] = 0;
3057 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3058 			mddev->metadata_type[--namelen] = 0;
3059 		mddev->persistent = 0;
3060 		mddev->external = 1;
3061 		mddev->major_version = 0;
3062 		mddev->minor_version = 90;
3063 		return len;
3064 	}
3065 	major = simple_strtoul(buf, &e, 10);
3066 	if (e==buf || *e != '.')
3067 		return -EINVAL;
3068 	buf = e+1;
3069 	minor = simple_strtoul(buf, &e, 10);
3070 	if (e==buf || (*e && *e != '\n') )
3071 		return -EINVAL;
3072 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3073 		return -ENOENT;
3074 	mddev->major_version = major;
3075 	mddev->minor_version = minor;
3076 	mddev->persistent = 1;
3077 	mddev->external = 0;
3078 	return len;
3079 }
3080 
3081 static struct md_sysfs_entry md_metadata =
3082 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3083 
3084 static ssize_t
3085 action_show(mddev_t *mddev, char *page)
3086 {
3087 	char *type = "idle";
3088 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3089 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3090 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3091 			type = "reshape";
3092 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3093 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3094 				type = "resync";
3095 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3096 				type = "check";
3097 			else
3098 				type = "repair";
3099 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3100 			type = "recover";
3101 	}
3102 	return sprintf(page, "%s\n", type);
3103 }
3104 
3105 static ssize_t
3106 action_store(mddev_t *mddev, const char *page, size_t len)
3107 {
3108 	if (!mddev->pers || !mddev->pers->sync_request)
3109 		return -EINVAL;
3110 
3111 	if (cmd_match(page, "idle")) {
3112 		if (mddev->sync_thread) {
3113 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3114 			md_unregister_thread(mddev->sync_thread);
3115 			mddev->sync_thread = NULL;
3116 			mddev->recovery = 0;
3117 		}
3118 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3119 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3120 		return -EBUSY;
3121 	else if (cmd_match(page, "resync"))
3122 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3123 	else if (cmd_match(page, "recover")) {
3124 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3125 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3126 	} else if (cmd_match(page, "reshape")) {
3127 		int err;
3128 		if (mddev->pers->start_reshape == NULL)
3129 			return -EINVAL;
3130 		err = mddev->pers->start_reshape(mddev);
3131 		if (err)
3132 			return err;
3133 		sysfs_notify(&mddev->kobj, NULL, "degraded");
3134 	} else {
3135 		if (cmd_match(page, "check"))
3136 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3137 		else if (!cmd_match(page, "repair"))
3138 			return -EINVAL;
3139 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3140 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3141 	}
3142 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3143 	md_wakeup_thread(mddev->thread);
3144 	sysfs_notify_dirent(mddev->sysfs_action);
3145 	return len;
3146 }
3147 
3148 static ssize_t
3149 mismatch_cnt_show(mddev_t *mddev, char *page)
3150 {
3151 	return sprintf(page, "%llu\n",
3152 		       (unsigned long long) mddev->resync_mismatches);
3153 }
3154 
3155 static struct md_sysfs_entry md_scan_mode =
3156 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
3157 
3158 
3159 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
3160 
3161 static ssize_t
3162 sync_min_show(mddev_t *mddev, char *page)
3163 {
3164 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
3165 		       mddev->sync_speed_min ? "local": "system");
3166 }
3167 
3168 static ssize_t
3169 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
3170 {
3171 	int min;
3172 	char *e;
3173 	if (strncmp(buf, "system", 6)==0) {
3174 		mddev->sync_speed_min = 0;
3175 		return len;
3176 	}
3177 	min = simple_strtoul(buf, &e, 10);
3178 	if (buf == e || (*e && *e != '\n') || min <= 0)
3179 		return -EINVAL;
3180 	mddev->sync_speed_min = min;
3181 	return len;
3182 }
3183 
3184 static struct md_sysfs_entry md_sync_min =
3185 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
3186 
3187 static ssize_t
3188 sync_max_show(mddev_t *mddev, char *page)
3189 {
3190 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
3191 		       mddev->sync_speed_max ? "local": "system");
3192 }
3193 
3194 static ssize_t
3195 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
3196 {
3197 	int max;
3198 	char *e;
3199 	if (strncmp(buf, "system", 6)==0) {
3200 		mddev->sync_speed_max = 0;
3201 		return len;
3202 	}
3203 	max = simple_strtoul(buf, &e, 10);
3204 	if (buf == e || (*e && *e != '\n') || max <= 0)
3205 		return -EINVAL;
3206 	mddev->sync_speed_max = max;
3207 	return len;
3208 }
3209 
3210 static struct md_sysfs_entry md_sync_max =
3211 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
3212 
3213 static ssize_t
3214 degraded_show(mddev_t *mddev, char *page)
3215 {
3216 	return sprintf(page, "%d\n", mddev->degraded);
3217 }
3218 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
3219 
3220 static ssize_t
3221 sync_force_parallel_show(mddev_t *mddev, char *page)
3222 {
3223 	return sprintf(page, "%d\n", mddev->parallel_resync);
3224 }
3225 
3226 static ssize_t
3227 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
3228 {
3229 	long n;
3230 
3231 	if (strict_strtol(buf, 10, &n))
3232 		return -EINVAL;
3233 
3234 	if (n != 0 && n != 1)
3235 		return -EINVAL;
3236 
3237 	mddev->parallel_resync = n;
3238 
3239 	if (mddev->sync_thread)
3240 		wake_up(&resync_wait);
3241 
3242 	return len;
3243 }
3244 
3245 /* force parallel resync, even with shared block devices */
3246 static struct md_sysfs_entry md_sync_force_parallel =
3247 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
3248        sync_force_parallel_show, sync_force_parallel_store);
3249 
3250 static ssize_t
3251 sync_speed_show(mddev_t *mddev, char *page)
3252 {
3253 	unsigned long resync, dt, db;
3254 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
3255 	dt = (jiffies - mddev->resync_mark) / HZ;
3256 	if (!dt) dt++;
3257 	db = resync - mddev->resync_mark_cnt;
3258 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
3259 }
3260 
3261 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
3262 
3263 static ssize_t
3264 sync_completed_show(mddev_t *mddev, char *page)
3265 {
3266 	unsigned long max_blocks, resync;
3267 
3268 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3269 		max_blocks = mddev->resync_max_sectors;
3270 	else
3271 		max_blocks = mddev->size << 1;
3272 
3273 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
3274 	return sprintf(page, "%lu / %lu\n", resync, max_blocks);
3275 }
3276 
3277 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
3278 
3279 static ssize_t
3280 min_sync_show(mddev_t *mddev, char *page)
3281 {
3282 	return sprintf(page, "%llu\n",
3283 		       (unsigned long long)mddev->resync_min);
3284 }
3285 static ssize_t
3286 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
3287 {
3288 	unsigned long long min;
3289 	if (strict_strtoull(buf, 10, &min))
3290 		return -EINVAL;
3291 	if (min > mddev->resync_max)
3292 		return -EINVAL;
3293 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3294 		return -EBUSY;
3295 
3296 	/* Must be a multiple of chunk_size */
3297 	if (mddev->chunk_size) {
3298 		if (min & (sector_t)((mddev->chunk_size>>9)-1))
3299 			return -EINVAL;
3300 	}
3301 	mddev->resync_min = min;
3302 
3303 	return len;
3304 }
3305 
3306 static struct md_sysfs_entry md_min_sync =
3307 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
3308 
3309 static ssize_t
3310 max_sync_show(mddev_t *mddev, char *page)
3311 {
3312 	if (mddev->resync_max == MaxSector)
3313 		return sprintf(page, "max\n");
3314 	else
3315 		return sprintf(page, "%llu\n",
3316 			       (unsigned long long)mddev->resync_max);
3317 }
3318 static ssize_t
3319 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
3320 {
3321 	if (strncmp(buf, "max", 3) == 0)
3322 		mddev->resync_max = MaxSector;
3323 	else {
3324 		unsigned long long max;
3325 		if (strict_strtoull(buf, 10, &max))
3326 			return -EINVAL;
3327 		if (max < mddev->resync_min)
3328 			return -EINVAL;
3329 		if (max < mddev->resync_max &&
3330 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3331 			return -EBUSY;
3332 
3333 		/* Must be a multiple of chunk_size */
3334 		if (mddev->chunk_size) {
3335 			if (max & (sector_t)((mddev->chunk_size>>9)-1))
3336 				return -EINVAL;
3337 		}
3338 		mddev->resync_max = max;
3339 	}
3340 	wake_up(&mddev->recovery_wait);
3341 	return len;
3342 }
3343 
3344 static struct md_sysfs_entry md_max_sync =
3345 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
3346 
3347 static ssize_t
3348 suspend_lo_show(mddev_t *mddev, char *page)
3349 {
3350 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
3351 }
3352 
3353 static ssize_t
3354 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
3355 {
3356 	char *e;
3357 	unsigned long long new = simple_strtoull(buf, &e, 10);
3358 
3359 	if (mddev->pers->quiesce == NULL)
3360 		return -EINVAL;
3361 	if (buf == e || (*e && *e != '\n'))
3362 		return -EINVAL;
3363 	if (new >= mddev->suspend_hi ||
3364 	    (new > mddev->suspend_lo && new < mddev->suspend_hi)) {
3365 		mddev->suspend_lo = new;
3366 		mddev->pers->quiesce(mddev, 2);
3367 		return len;
3368 	} else
3369 		return -EINVAL;
3370 }
3371 static struct md_sysfs_entry md_suspend_lo =
3372 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
3373 
3374 
3375 static ssize_t
3376 suspend_hi_show(mddev_t *mddev, char *page)
3377 {
3378 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
3379 }
3380 
3381 static ssize_t
3382 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
3383 {
3384 	char *e;
3385 	unsigned long long new = simple_strtoull(buf, &e, 10);
3386 
3387 	if (mddev->pers->quiesce == NULL)
3388 		return -EINVAL;
3389 	if (buf == e || (*e && *e != '\n'))
3390 		return -EINVAL;
3391 	if ((new <= mddev->suspend_lo && mddev->suspend_lo >= mddev->suspend_hi) ||
3392 	    (new > mddev->suspend_lo && new > mddev->suspend_hi)) {
3393 		mddev->suspend_hi = new;
3394 		mddev->pers->quiesce(mddev, 1);
3395 		mddev->pers->quiesce(mddev, 0);
3396 		return len;
3397 	} else
3398 		return -EINVAL;
3399 }
3400 static struct md_sysfs_entry md_suspend_hi =
3401 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
3402 
3403 static ssize_t
3404 reshape_position_show(mddev_t *mddev, char *page)
3405 {
3406 	if (mddev->reshape_position != MaxSector)
3407 		return sprintf(page, "%llu\n",
3408 			       (unsigned long long)mddev->reshape_position);
3409 	strcpy(page, "none\n");
3410 	return 5;
3411 }
3412 
3413 static ssize_t
3414 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
3415 {
3416 	char *e;
3417 	unsigned long long new = simple_strtoull(buf, &e, 10);
3418 	if (mddev->pers)
3419 		return -EBUSY;
3420 	if (buf == e || (*e && *e != '\n'))
3421 		return -EINVAL;
3422 	mddev->reshape_position = new;
3423 	mddev->delta_disks = 0;
3424 	mddev->new_level = mddev->level;
3425 	mddev->new_layout = mddev->layout;
3426 	mddev->new_chunk = mddev->chunk_size;
3427 	return len;
3428 }
3429 
3430 static struct md_sysfs_entry md_reshape_position =
3431 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
3432        reshape_position_store);
3433 
3434 
3435 static struct attribute *md_default_attrs[] = {
3436 	&md_level.attr,
3437 	&md_layout.attr,
3438 	&md_raid_disks.attr,
3439 	&md_chunk_size.attr,
3440 	&md_size.attr,
3441 	&md_resync_start.attr,
3442 	&md_metadata.attr,
3443 	&md_new_device.attr,
3444 	&md_safe_delay.attr,
3445 	&md_array_state.attr,
3446 	&md_reshape_position.attr,
3447 	NULL,
3448 };
3449 
3450 static struct attribute *md_redundancy_attrs[] = {
3451 	&md_scan_mode.attr,
3452 	&md_mismatches.attr,
3453 	&md_sync_min.attr,
3454 	&md_sync_max.attr,
3455 	&md_sync_speed.attr,
3456 	&md_sync_force_parallel.attr,
3457 	&md_sync_completed.attr,
3458 	&md_min_sync.attr,
3459 	&md_max_sync.attr,
3460 	&md_suspend_lo.attr,
3461 	&md_suspend_hi.attr,
3462 	&md_bitmap.attr,
3463 	&md_degraded.attr,
3464 	NULL,
3465 };
3466 static struct attribute_group md_redundancy_group = {
3467 	.name = NULL,
3468 	.attrs = md_redundancy_attrs,
3469 };
3470 
3471 
3472 static ssize_t
3473 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3474 {
3475 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3476 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3477 	ssize_t rv;
3478 
3479 	if (!entry->show)
3480 		return -EIO;
3481 	rv = mddev_lock(mddev);
3482 	if (!rv) {
3483 		rv = entry->show(mddev, page);
3484 		mddev_unlock(mddev);
3485 	}
3486 	return rv;
3487 }
3488 
3489 static ssize_t
3490 md_attr_store(struct kobject *kobj, struct attribute *attr,
3491 	      const char *page, size_t length)
3492 {
3493 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
3494 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
3495 	ssize_t rv;
3496 
3497 	if (!entry->store)
3498 		return -EIO;
3499 	if (!capable(CAP_SYS_ADMIN))
3500 		return -EACCES;
3501 	rv = mddev_lock(mddev);
3502 	if (mddev->hold_active == UNTIL_IOCTL)
3503 		mddev->hold_active = 0;
3504 	if (!rv) {
3505 		rv = entry->store(mddev, page, length);
3506 		mddev_unlock(mddev);
3507 	}
3508 	return rv;
3509 }
3510 
3511 static void md_free(struct kobject *ko)
3512 {
3513 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
3514 
3515 	if (mddev->sysfs_state)
3516 		sysfs_put(mddev->sysfs_state);
3517 
3518 	if (mddev->gendisk) {
3519 		del_gendisk(mddev->gendisk);
3520 		put_disk(mddev->gendisk);
3521 	}
3522 	if (mddev->queue)
3523 		blk_cleanup_queue(mddev->queue);
3524 
3525 	kfree(mddev);
3526 }
3527 
3528 static struct sysfs_ops md_sysfs_ops = {
3529 	.show	= md_attr_show,
3530 	.store	= md_attr_store,
3531 };
3532 static struct kobj_type md_ktype = {
3533 	.release	= md_free,
3534 	.sysfs_ops	= &md_sysfs_ops,
3535 	.default_attrs	= md_default_attrs,
3536 };
3537 
3538 int mdp_major = 0;
3539 
3540 static void mddev_delayed_delete(struct work_struct *ws)
3541 {
3542 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
3543 
3544 	if (mddev->private == &md_redundancy_group) {
3545 		sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
3546 		if (mddev->sysfs_action)
3547 			sysfs_put(mddev->sysfs_action);
3548 		mddev->sysfs_action = NULL;
3549 		mddev->private = NULL;
3550 	}
3551 	kobject_del(&mddev->kobj);
3552 	kobject_put(&mddev->kobj);
3553 }
3554 
3555 static int md_alloc(dev_t dev, char *name)
3556 {
3557 	static DEFINE_MUTEX(disks_mutex);
3558 	mddev_t *mddev = mddev_find(dev);
3559 	struct gendisk *disk;
3560 	int partitioned;
3561 	int shift;
3562 	int unit;
3563 	int error;
3564 
3565 	if (!mddev)
3566 		return -ENODEV;
3567 
3568 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
3569 	shift = partitioned ? MdpMinorShift : 0;
3570 	unit = MINOR(mddev->unit) >> shift;
3571 
3572 	/* wait for any previous instance if this device
3573 	 * to be completed removed (mddev_delayed_delete).
3574 	 */
3575 	flush_scheduled_work();
3576 
3577 	mutex_lock(&disks_mutex);
3578 	if (mddev->gendisk) {
3579 		mutex_unlock(&disks_mutex);
3580 		mddev_put(mddev);
3581 		return -EEXIST;
3582 	}
3583 
3584 	if (name) {
3585 		/* Need to ensure that 'name' is not a duplicate.
3586 		 */
3587 		mddev_t *mddev2;
3588 		spin_lock(&all_mddevs_lock);
3589 
3590 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
3591 			if (mddev2->gendisk &&
3592 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
3593 				spin_unlock(&all_mddevs_lock);
3594 				return -EEXIST;
3595 			}
3596 		spin_unlock(&all_mddevs_lock);
3597 	}
3598 
3599 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
3600 	if (!mddev->queue) {
3601 		mutex_unlock(&disks_mutex);
3602 		mddev_put(mddev);
3603 		return -ENOMEM;
3604 	}
3605 	/* Can be unlocked because the queue is new: no concurrency */
3606 	queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
3607 
3608 	blk_queue_make_request(mddev->queue, md_fail_request);
3609 
3610 	disk = alloc_disk(1 << shift);
3611 	if (!disk) {
3612 		mutex_unlock(&disks_mutex);
3613 		blk_cleanup_queue(mddev->queue);
3614 		mddev->queue = NULL;
3615 		mddev_put(mddev);
3616 		return -ENOMEM;
3617 	}
3618 	disk->major = MAJOR(mddev->unit);
3619 	disk->first_minor = unit << shift;
3620 	if (name)
3621 		strcpy(disk->disk_name, name);
3622 	else if (partitioned)
3623 		sprintf(disk->disk_name, "md_d%d", unit);
3624 	else
3625 		sprintf(disk->disk_name, "md%d", unit);
3626 	disk->fops = &md_fops;
3627 	disk->private_data = mddev;
3628 	disk->queue = mddev->queue;
3629 	/* Allow extended partitions.  This makes the
3630 	 * 'mdp' device redundant, but we can't really
3631 	 * remove it now.
3632 	 */
3633 	disk->flags |= GENHD_FL_EXT_DEVT;
3634 	add_disk(disk);
3635 	mddev->gendisk = disk;
3636 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
3637 				     &disk_to_dev(disk)->kobj, "%s", "md");
3638 	mutex_unlock(&disks_mutex);
3639 	if (error)
3640 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
3641 		       disk->disk_name);
3642 	else {
3643 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
3644 		mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
3645 	}
3646 	mddev_put(mddev);
3647 	return 0;
3648 }
3649 
3650 static struct kobject *md_probe(dev_t dev, int *part, void *data)
3651 {
3652 	md_alloc(dev, NULL);
3653 	return NULL;
3654 }
3655 
3656 static int add_named_array(const char *val, struct kernel_param *kp)
3657 {
3658 	/* val must be "md_*" where * is not all digits.
3659 	 * We allocate an array with a large free minor number, and
3660 	 * set the name to val.  val must not already be an active name.
3661 	 */
3662 	int len = strlen(val);
3663 	char buf[DISK_NAME_LEN];
3664 
3665 	while (len && val[len-1] == '\n')
3666 		len--;
3667 	if (len >= DISK_NAME_LEN)
3668 		return -E2BIG;
3669 	strlcpy(buf, val, len+1);
3670 	if (strncmp(buf, "md_", 3) != 0)
3671 		return -EINVAL;
3672 	return md_alloc(0, buf);
3673 }
3674 
3675 static void md_safemode_timeout(unsigned long data)
3676 {
3677 	mddev_t *mddev = (mddev_t *) data;
3678 
3679 	if (!atomic_read(&mddev->writes_pending)) {
3680 		mddev->safemode = 1;
3681 		if (mddev->external)
3682 			sysfs_notify_dirent(mddev->sysfs_state);
3683 	}
3684 	md_wakeup_thread(mddev->thread);
3685 }
3686 
3687 static int start_dirty_degraded;
3688 
3689 static int do_md_run(mddev_t * mddev)
3690 {
3691 	int err;
3692 	int chunk_size;
3693 	mdk_rdev_t *rdev;
3694 	struct gendisk *disk;
3695 	struct mdk_personality *pers;
3696 	char b[BDEVNAME_SIZE];
3697 
3698 	if (list_empty(&mddev->disks))
3699 		/* cannot run an array with no devices.. */
3700 		return -EINVAL;
3701 
3702 	if (mddev->pers)
3703 		return -EBUSY;
3704 
3705 	/*
3706 	 * Analyze all RAID superblock(s)
3707 	 */
3708 	if (!mddev->raid_disks) {
3709 		if (!mddev->persistent)
3710 			return -EINVAL;
3711 		analyze_sbs(mddev);
3712 	}
3713 
3714 	chunk_size = mddev->chunk_size;
3715 
3716 	if (chunk_size) {
3717 		if (chunk_size > MAX_CHUNK_SIZE) {
3718 			printk(KERN_ERR "too big chunk_size: %d > %d\n",
3719 				chunk_size, MAX_CHUNK_SIZE);
3720 			return -EINVAL;
3721 		}
3722 		/*
3723 		 * chunk-size has to be a power of 2
3724 		 */
3725 		if ( (1 << ffz(~chunk_size)) != chunk_size) {
3726 			printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
3727 			return -EINVAL;
3728 		}
3729 
3730 		/* devices must have minimum size of one chunk */
3731 		list_for_each_entry(rdev, &mddev->disks, same_set) {
3732 			if (test_bit(Faulty, &rdev->flags))
3733 				continue;
3734 			if (rdev->size < chunk_size / 1024) {
3735 				printk(KERN_WARNING
3736 					"md: Dev %s smaller than chunk_size:"
3737 					" %lluk < %dk\n",
3738 					bdevname(rdev->bdev,b),
3739 					(unsigned long long)rdev->size,
3740 					chunk_size / 1024);
3741 				return -EINVAL;
3742 			}
3743 		}
3744 	}
3745 
3746 	if (mddev->level != LEVEL_NONE)
3747 		request_module("md-level-%d", mddev->level);
3748 	else if (mddev->clevel[0])
3749 		request_module("md-%s", mddev->clevel);
3750 
3751 	/*
3752 	 * Drop all container device buffers, from now on
3753 	 * the only valid external interface is through the md
3754 	 * device.
3755 	 */
3756 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3757 		if (test_bit(Faulty, &rdev->flags))
3758 			continue;
3759 		sync_blockdev(rdev->bdev);
3760 		invalidate_bdev(rdev->bdev);
3761 
3762 		/* perform some consistency tests on the device.
3763 		 * We don't want the data to overlap the metadata,
3764 		 * Internal Bitmap issues has handled elsewhere.
3765 		 */
3766 		if (rdev->data_offset < rdev->sb_start) {
3767 			if (mddev->size &&
3768 			    rdev->data_offset + mddev->size*2
3769 			    > rdev->sb_start) {
3770 				printk("md: %s: data overlaps metadata\n",
3771 				       mdname(mddev));
3772 				return -EINVAL;
3773 			}
3774 		} else {
3775 			if (rdev->sb_start + rdev->sb_size/512
3776 			    > rdev->data_offset) {
3777 				printk("md: %s: metadata overlaps data\n",
3778 				       mdname(mddev));
3779 				return -EINVAL;
3780 			}
3781 		}
3782 		sysfs_notify_dirent(rdev->sysfs_state);
3783 	}
3784 
3785 	md_probe(mddev->unit, NULL, NULL);
3786 	disk = mddev->gendisk;
3787 	if (!disk)
3788 		return -ENOMEM;
3789 
3790 	spin_lock(&pers_lock);
3791 	pers = find_pers(mddev->level, mddev->clevel);
3792 	if (!pers || !try_module_get(pers->owner)) {
3793 		spin_unlock(&pers_lock);
3794 		if (mddev->level != LEVEL_NONE)
3795 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
3796 			       mddev->level);
3797 		else
3798 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
3799 			       mddev->clevel);
3800 		return -EINVAL;
3801 	}
3802 	mddev->pers = pers;
3803 	spin_unlock(&pers_lock);
3804 	mddev->level = pers->level;
3805 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3806 
3807 	if (mddev->reshape_position != MaxSector &&
3808 	    pers->start_reshape == NULL) {
3809 		/* This personality cannot handle reshaping... */
3810 		mddev->pers = NULL;
3811 		module_put(pers->owner);
3812 		return -EINVAL;
3813 	}
3814 
3815 	if (pers->sync_request) {
3816 		/* Warn if this is a potentially silly
3817 		 * configuration.
3818 		 */
3819 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
3820 		mdk_rdev_t *rdev2;
3821 		int warned = 0;
3822 
3823 		list_for_each_entry(rdev, &mddev->disks, same_set)
3824 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
3825 				if (rdev < rdev2 &&
3826 				    rdev->bdev->bd_contains ==
3827 				    rdev2->bdev->bd_contains) {
3828 					printk(KERN_WARNING
3829 					       "%s: WARNING: %s appears to be"
3830 					       " on the same physical disk as"
3831 					       " %s.\n",
3832 					       mdname(mddev),
3833 					       bdevname(rdev->bdev,b),
3834 					       bdevname(rdev2->bdev,b2));
3835 					warned = 1;
3836 				}
3837 			}
3838 
3839 		if (warned)
3840 			printk(KERN_WARNING
3841 			       "True protection against single-disk"
3842 			       " failure might be compromised.\n");
3843 	}
3844 
3845 	mddev->recovery = 0;
3846 	mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
3847 	mddev->barriers_work = 1;
3848 	mddev->ok_start_degraded = start_dirty_degraded;
3849 
3850 	if (start_readonly)
3851 		mddev->ro = 2; /* read-only, but switch on first write */
3852 
3853 	err = mddev->pers->run(mddev);
3854 	if (err)
3855 		printk(KERN_ERR "md: pers->run() failed ...\n");
3856 	else if (mddev->pers->sync_request) {
3857 		err = bitmap_create(mddev);
3858 		if (err) {
3859 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
3860 			       mdname(mddev), err);
3861 			mddev->pers->stop(mddev);
3862 		}
3863 	}
3864 	if (err) {
3865 		module_put(mddev->pers->owner);
3866 		mddev->pers = NULL;
3867 		bitmap_destroy(mddev);
3868 		return err;
3869 	}
3870 	if (mddev->pers->sync_request) {
3871 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3872 			printk(KERN_WARNING
3873 			       "md: cannot register extra attributes for %s\n",
3874 			       mdname(mddev));
3875 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3876 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
3877 		mddev->ro = 0;
3878 
3879  	atomic_set(&mddev->writes_pending,0);
3880 	mddev->safemode = 0;
3881 	mddev->safemode_timer.function = md_safemode_timeout;
3882 	mddev->safemode_timer.data = (unsigned long) mddev;
3883 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
3884 	mddev->in_sync = 1;
3885 
3886 	list_for_each_entry(rdev, &mddev->disks, same_set)
3887 		if (rdev->raid_disk >= 0) {
3888 			char nm[20];
3889 			sprintf(nm, "rd%d", rdev->raid_disk);
3890 			if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
3891 				printk("md: cannot register %s for %s\n",
3892 				       nm, mdname(mddev));
3893 		}
3894 
3895 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3896 
3897 	if (mddev->flags)
3898 		md_update_sb(mddev, 0);
3899 
3900 	set_capacity(disk, mddev->array_sectors);
3901 
3902 	/* If we call blk_queue_make_request here, it will
3903 	 * re-initialise max_sectors etc which may have been
3904 	 * refined inside -> run.  So just set the bits we need to set.
3905 	 * Most initialisation happended when we called
3906 	 * blk_queue_make_request(..., md_fail_request)
3907 	 * earlier.
3908 	 */
3909 	mddev->queue->queuedata = mddev;
3910 	mddev->queue->make_request_fn = mddev->pers->make_request;
3911 
3912 	/* If there is a partially-recovered drive we need to
3913 	 * start recovery here.  If we leave it to md_check_recovery,
3914 	 * it will remove the drives and not do the right thing
3915 	 */
3916 	if (mddev->degraded && !mddev->sync_thread) {
3917 		int spares = 0;
3918 		list_for_each_entry(rdev, &mddev->disks, same_set)
3919 			if (rdev->raid_disk >= 0 &&
3920 			    !test_bit(In_sync, &rdev->flags) &&
3921 			    !test_bit(Faulty, &rdev->flags))
3922 				/* complete an interrupted recovery */
3923 				spares++;
3924 		if (spares && mddev->pers->sync_request) {
3925 			mddev->recovery = 0;
3926 			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3927 			mddev->sync_thread = md_register_thread(md_do_sync,
3928 								mddev,
3929 								"%s_resync");
3930 			if (!mddev->sync_thread) {
3931 				printk(KERN_ERR "%s: could not start resync"
3932 				       " thread...\n",
3933 				       mdname(mddev));
3934 				/* leave the spares where they are, it shouldn't hurt */
3935 				mddev->recovery = 0;
3936 			}
3937 		}
3938 	}
3939 	md_wakeup_thread(mddev->thread);
3940 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
3941 
3942 	mddev->changed = 1;
3943 	md_new_event(mddev);
3944 	sysfs_notify_dirent(mddev->sysfs_state);
3945 	if (mddev->sysfs_action)
3946 		sysfs_notify_dirent(mddev->sysfs_action);
3947 	sysfs_notify(&mddev->kobj, NULL, "degraded");
3948 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
3949 	return 0;
3950 }
3951 
3952 static int restart_array(mddev_t *mddev)
3953 {
3954 	struct gendisk *disk = mddev->gendisk;
3955 
3956 	/* Complain if it has no devices */
3957 	if (list_empty(&mddev->disks))
3958 		return -ENXIO;
3959 	if (!mddev->pers)
3960 		return -EINVAL;
3961 	if (!mddev->ro)
3962 		return -EBUSY;
3963 	mddev->safemode = 0;
3964 	mddev->ro = 0;
3965 	set_disk_ro(disk, 0);
3966 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
3967 		mdname(mddev));
3968 	/* Kick recovery or resync if necessary */
3969 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3970 	md_wakeup_thread(mddev->thread);
3971 	md_wakeup_thread(mddev->sync_thread);
3972 	sysfs_notify_dirent(mddev->sysfs_state);
3973 	return 0;
3974 }
3975 
3976 /* similar to deny_write_access, but accounts for our holding a reference
3977  * to the file ourselves */
3978 static int deny_bitmap_write_access(struct file * file)
3979 {
3980 	struct inode *inode = file->f_mapping->host;
3981 
3982 	spin_lock(&inode->i_lock);
3983 	if (atomic_read(&inode->i_writecount) > 1) {
3984 		spin_unlock(&inode->i_lock);
3985 		return -ETXTBSY;
3986 	}
3987 	atomic_set(&inode->i_writecount, -1);
3988 	spin_unlock(&inode->i_lock);
3989 
3990 	return 0;
3991 }
3992 
3993 static void restore_bitmap_write_access(struct file *file)
3994 {
3995 	struct inode *inode = file->f_mapping->host;
3996 
3997 	spin_lock(&inode->i_lock);
3998 	atomic_set(&inode->i_writecount, 1);
3999 	spin_unlock(&inode->i_lock);
4000 }
4001 
4002 /* mode:
4003  *   0 - completely stop and dis-assemble array
4004  *   1 - switch to readonly
4005  *   2 - stop but do not disassemble array
4006  */
4007 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
4008 {
4009 	int err = 0;
4010 	struct gendisk *disk = mddev->gendisk;
4011 
4012 	if (atomic_read(&mddev->openers) > is_open) {
4013 		printk("md: %s still in use.\n",mdname(mddev));
4014 		return -EBUSY;
4015 	}
4016 
4017 	if (mddev->pers) {
4018 
4019 		if (mddev->sync_thread) {
4020 			set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4021 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4022 			md_unregister_thread(mddev->sync_thread);
4023 			mddev->sync_thread = NULL;
4024 		}
4025 
4026 		del_timer_sync(&mddev->safemode_timer);
4027 
4028 		switch(mode) {
4029 		case 1: /* readonly */
4030 			err  = -ENXIO;
4031 			if (mddev->ro==1)
4032 				goto out;
4033 			mddev->ro = 1;
4034 			break;
4035 		case 0: /* disassemble */
4036 		case 2: /* stop */
4037 			bitmap_flush(mddev);
4038 			md_super_wait(mddev);
4039 			if (mddev->ro)
4040 				set_disk_ro(disk, 0);
4041 			blk_queue_make_request(mddev->queue, md_fail_request);
4042 			mddev->pers->stop(mddev);
4043 			mddev->queue->merge_bvec_fn = NULL;
4044 			mddev->queue->unplug_fn = NULL;
4045 			mddev->queue->backing_dev_info.congested_fn = NULL;
4046 			module_put(mddev->pers->owner);
4047 			if (mddev->pers->sync_request)
4048 				mddev->private = &md_redundancy_group;
4049 			mddev->pers = NULL;
4050 			/* tell userspace to handle 'inactive' */
4051 			sysfs_notify_dirent(mddev->sysfs_state);
4052 
4053 			set_capacity(disk, 0);
4054 			mddev->changed = 1;
4055 
4056 			if (mddev->ro)
4057 				mddev->ro = 0;
4058 		}
4059 		if (!mddev->in_sync || mddev->flags) {
4060 			/* mark array as shutdown cleanly */
4061 			mddev->in_sync = 1;
4062 			md_update_sb(mddev, 1);
4063 		}
4064 		if (mode == 1)
4065 			set_disk_ro(disk, 1);
4066 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4067 	}
4068 
4069 	/*
4070 	 * Free resources if final stop
4071 	 */
4072 	if (mode == 0) {
4073 		mdk_rdev_t *rdev;
4074 
4075 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
4076 
4077 		bitmap_destroy(mddev);
4078 		if (mddev->bitmap_file) {
4079 			restore_bitmap_write_access(mddev->bitmap_file);
4080 			fput(mddev->bitmap_file);
4081 			mddev->bitmap_file = NULL;
4082 		}
4083 		mddev->bitmap_offset = 0;
4084 
4085 		list_for_each_entry(rdev, &mddev->disks, same_set)
4086 			if (rdev->raid_disk >= 0) {
4087 				char nm[20];
4088 				sprintf(nm, "rd%d", rdev->raid_disk);
4089 				sysfs_remove_link(&mddev->kobj, nm);
4090 			}
4091 
4092 		/* make sure all md_delayed_delete calls have finished */
4093 		flush_scheduled_work();
4094 
4095 		export_array(mddev);
4096 
4097 		mddev->array_sectors = 0;
4098 		mddev->size = 0;
4099 		mddev->raid_disks = 0;
4100 		mddev->recovery_cp = 0;
4101 		mddev->resync_min = 0;
4102 		mddev->resync_max = MaxSector;
4103 		mddev->reshape_position = MaxSector;
4104 		mddev->external = 0;
4105 		mddev->persistent = 0;
4106 		mddev->level = LEVEL_NONE;
4107 		mddev->clevel[0] = 0;
4108 		mddev->flags = 0;
4109 		mddev->ro = 0;
4110 		mddev->metadata_type[0] = 0;
4111 		mddev->chunk_size = 0;
4112 		mddev->ctime = mddev->utime = 0;
4113 		mddev->layout = 0;
4114 		mddev->max_disks = 0;
4115 		mddev->events = 0;
4116 		mddev->delta_disks = 0;
4117 		mddev->new_level = LEVEL_NONE;
4118 		mddev->new_layout = 0;
4119 		mddev->new_chunk = 0;
4120 		mddev->curr_resync = 0;
4121 		mddev->resync_mismatches = 0;
4122 		mddev->suspend_lo = mddev->suspend_hi = 0;
4123 		mddev->sync_speed_min = mddev->sync_speed_max = 0;
4124 		mddev->recovery = 0;
4125 		mddev->in_sync = 0;
4126 		mddev->changed = 0;
4127 		mddev->degraded = 0;
4128 		mddev->barriers_work = 0;
4129 		mddev->safemode = 0;
4130 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4131 		if (mddev->hold_active == UNTIL_STOP)
4132 			mddev->hold_active = 0;
4133 
4134 	} else if (mddev->pers)
4135 		printk(KERN_INFO "md: %s switched to read-only mode.\n",
4136 			mdname(mddev));
4137 	err = 0;
4138 	md_new_event(mddev);
4139 	sysfs_notify_dirent(mddev->sysfs_state);
4140 out:
4141 	return err;
4142 }
4143 
4144 #ifndef MODULE
4145 static void autorun_array(mddev_t *mddev)
4146 {
4147 	mdk_rdev_t *rdev;
4148 	int err;
4149 
4150 	if (list_empty(&mddev->disks))
4151 		return;
4152 
4153 	printk(KERN_INFO "md: running: ");
4154 
4155 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4156 		char b[BDEVNAME_SIZE];
4157 		printk("<%s>", bdevname(rdev->bdev,b));
4158 	}
4159 	printk("\n");
4160 
4161 	err = do_md_run(mddev);
4162 	if (err) {
4163 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
4164 		do_md_stop(mddev, 0, 0);
4165 	}
4166 }
4167 
4168 /*
4169  * lets try to run arrays based on all disks that have arrived
4170  * until now. (those are in pending_raid_disks)
4171  *
4172  * the method: pick the first pending disk, collect all disks with
4173  * the same UUID, remove all from the pending list and put them into
4174  * the 'same_array' list. Then order this list based on superblock
4175  * update time (freshest comes first), kick out 'old' disks and
4176  * compare superblocks. If everything's fine then run it.
4177  *
4178  * If "unit" is allocated, then bump its reference count
4179  */
4180 static void autorun_devices(int part)
4181 {
4182 	mdk_rdev_t *rdev0, *rdev, *tmp;
4183 	mddev_t *mddev;
4184 	char b[BDEVNAME_SIZE];
4185 
4186 	printk(KERN_INFO "md: autorun ...\n");
4187 	while (!list_empty(&pending_raid_disks)) {
4188 		int unit;
4189 		dev_t dev;
4190 		LIST_HEAD(candidates);
4191 		rdev0 = list_entry(pending_raid_disks.next,
4192 					 mdk_rdev_t, same_set);
4193 
4194 		printk(KERN_INFO "md: considering %s ...\n",
4195 			bdevname(rdev0->bdev,b));
4196 		INIT_LIST_HEAD(&candidates);
4197 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
4198 			if (super_90_load(rdev, rdev0, 0) >= 0) {
4199 				printk(KERN_INFO "md:  adding %s ...\n",
4200 					bdevname(rdev->bdev,b));
4201 				list_move(&rdev->same_set, &candidates);
4202 			}
4203 		/*
4204 		 * now we have a set of devices, with all of them having
4205 		 * mostly sane superblocks. It's time to allocate the
4206 		 * mddev.
4207 		 */
4208 		if (part) {
4209 			dev = MKDEV(mdp_major,
4210 				    rdev0->preferred_minor << MdpMinorShift);
4211 			unit = MINOR(dev) >> MdpMinorShift;
4212 		} else {
4213 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
4214 			unit = MINOR(dev);
4215 		}
4216 		if (rdev0->preferred_minor != unit) {
4217 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
4218 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
4219 			break;
4220 		}
4221 
4222 		md_probe(dev, NULL, NULL);
4223 		mddev = mddev_find(dev);
4224 		if (!mddev || !mddev->gendisk) {
4225 			if (mddev)
4226 				mddev_put(mddev);
4227 			printk(KERN_ERR
4228 				"md: cannot allocate memory for md drive.\n");
4229 			break;
4230 		}
4231 		if (mddev_lock(mddev))
4232 			printk(KERN_WARNING "md: %s locked, cannot run\n",
4233 			       mdname(mddev));
4234 		else if (mddev->raid_disks || mddev->major_version
4235 			 || !list_empty(&mddev->disks)) {
4236 			printk(KERN_WARNING
4237 				"md: %s already running, cannot run %s\n",
4238 				mdname(mddev), bdevname(rdev0->bdev,b));
4239 			mddev_unlock(mddev);
4240 		} else {
4241 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
4242 			mddev->persistent = 1;
4243 			rdev_for_each_list(rdev, tmp, &candidates) {
4244 				list_del_init(&rdev->same_set);
4245 				if (bind_rdev_to_array(rdev, mddev))
4246 					export_rdev(rdev);
4247 			}
4248 			autorun_array(mddev);
4249 			mddev_unlock(mddev);
4250 		}
4251 		/* on success, candidates will be empty, on error
4252 		 * it won't...
4253 		 */
4254 		rdev_for_each_list(rdev, tmp, &candidates) {
4255 			list_del_init(&rdev->same_set);
4256 			export_rdev(rdev);
4257 		}
4258 		mddev_put(mddev);
4259 	}
4260 	printk(KERN_INFO "md: ... autorun DONE.\n");
4261 }
4262 #endif /* !MODULE */
4263 
4264 static int get_version(void __user * arg)
4265 {
4266 	mdu_version_t ver;
4267 
4268 	ver.major = MD_MAJOR_VERSION;
4269 	ver.minor = MD_MINOR_VERSION;
4270 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
4271 
4272 	if (copy_to_user(arg, &ver, sizeof(ver)))
4273 		return -EFAULT;
4274 
4275 	return 0;
4276 }
4277 
4278 static int get_array_info(mddev_t * mddev, void __user * arg)
4279 {
4280 	mdu_array_info_t info;
4281 	int nr,working,active,failed,spare;
4282 	mdk_rdev_t *rdev;
4283 
4284 	nr=working=active=failed=spare=0;
4285 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4286 		nr++;
4287 		if (test_bit(Faulty, &rdev->flags))
4288 			failed++;
4289 		else {
4290 			working++;
4291 			if (test_bit(In_sync, &rdev->flags))
4292 				active++;
4293 			else
4294 				spare++;
4295 		}
4296 	}
4297 
4298 	info.major_version = mddev->major_version;
4299 	info.minor_version = mddev->minor_version;
4300 	info.patch_version = MD_PATCHLEVEL_VERSION;
4301 	info.ctime         = mddev->ctime;
4302 	info.level         = mddev->level;
4303 	info.size          = mddev->size;
4304 	if (info.size != mddev->size) /* overflow */
4305 		info.size = -1;
4306 	info.nr_disks      = nr;
4307 	info.raid_disks    = mddev->raid_disks;
4308 	info.md_minor      = mddev->md_minor;
4309 	info.not_persistent= !mddev->persistent;
4310 
4311 	info.utime         = mddev->utime;
4312 	info.state         = 0;
4313 	if (mddev->in_sync)
4314 		info.state = (1<<MD_SB_CLEAN);
4315 	if (mddev->bitmap && mddev->bitmap_offset)
4316 		info.state = (1<<MD_SB_BITMAP_PRESENT);
4317 	info.active_disks  = active;
4318 	info.working_disks = working;
4319 	info.failed_disks  = failed;
4320 	info.spare_disks   = spare;
4321 
4322 	info.layout        = mddev->layout;
4323 	info.chunk_size    = mddev->chunk_size;
4324 
4325 	if (copy_to_user(arg, &info, sizeof(info)))
4326 		return -EFAULT;
4327 
4328 	return 0;
4329 }
4330 
4331 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
4332 {
4333 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
4334 	char *ptr, *buf = NULL;
4335 	int err = -ENOMEM;
4336 
4337 	if (md_allow_write(mddev))
4338 		file = kmalloc(sizeof(*file), GFP_NOIO);
4339 	else
4340 		file = kmalloc(sizeof(*file), GFP_KERNEL);
4341 
4342 	if (!file)
4343 		goto out;
4344 
4345 	/* bitmap disabled, zero the first byte and copy out */
4346 	if (!mddev->bitmap || !mddev->bitmap->file) {
4347 		file->pathname[0] = '\0';
4348 		goto copy_out;
4349 	}
4350 
4351 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
4352 	if (!buf)
4353 		goto out;
4354 
4355 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
4356 	if (IS_ERR(ptr))
4357 		goto out;
4358 
4359 	strcpy(file->pathname, ptr);
4360 
4361 copy_out:
4362 	err = 0;
4363 	if (copy_to_user(arg, file, sizeof(*file)))
4364 		err = -EFAULT;
4365 out:
4366 	kfree(buf);
4367 	kfree(file);
4368 	return err;
4369 }
4370 
4371 static int get_disk_info(mddev_t * mddev, void __user * arg)
4372 {
4373 	mdu_disk_info_t info;
4374 	mdk_rdev_t *rdev;
4375 
4376 	if (copy_from_user(&info, arg, sizeof(info)))
4377 		return -EFAULT;
4378 
4379 	rdev = find_rdev_nr(mddev, info.number);
4380 	if (rdev) {
4381 		info.major = MAJOR(rdev->bdev->bd_dev);
4382 		info.minor = MINOR(rdev->bdev->bd_dev);
4383 		info.raid_disk = rdev->raid_disk;
4384 		info.state = 0;
4385 		if (test_bit(Faulty, &rdev->flags))
4386 			info.state |= (1<<MD_DISK_FAULTY);
4387 		else if (test_bit(In_sync, &rdev->flags)) {
4388 			info.state |= (1<<MD_DISK_ACTIVE);
4389 			info.state |= (1<<MD_DISK_SYNC);
4390 		}
4391 		if (test_bit(WriteMostly, &rdev->flags))
4392 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
4393 	} else {
4394 		info.major = info.minor = 0;
4395 		info.raid_disk = -1;
4396 		info.state = (1<<MD_DISK_REMOVED);
4397 	}
4398 
4399 	if (copy_to_user(arg, &info, sizeof(info)))
4400 		return -EFAULT;
4401 
4402 	return 0;
4403 }
4404 
4405 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
4406 {
4407 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4408 	mdk_rdev_t *rdev;
4409 	dev_t dev = MKDEV(info->major,info->minor);
4410 
4411 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
4412 		return -EOVERFLOW;
4413 
4414 	if (!mddev->raid_disks) {
4415 		int err;
4416 		/* expecting a device which has a superblock */
4417 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
4418 		if (IS_ERR(rdev)) {
4419 			printk(KERN_WARNING
4420 				"md: md_import_device returned %ld\n",
4421 				PTR_ERR(rdev));
4422 			return PTR_ERR(rdev);
4423 		}
4424 		if (!list_empty(&mddev->disks)) {
4425 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
4426 							mdk_rdev_t, same_set);
4427 			int err = super_types[mddev->major_version]
4428 				.load_super(rdev, rdev0, mddev->minor_version);
4429 			if (err < 0) {
4430 				printk(KERN_WARNING
4431 					"md: %s has different UUID to %s\n",
4432 					bdevname(rdev->bdev,b),
4433 					bdevname(rdev0->bdev,b2));
4434 				export_rdev(rdev);
4435 				return -EINVAL;
4436 			}
4437 		}
4438 		err = bind_rdev_to_array(rdev, mddev);
4439 		if (err)
4440 			export_rdev(rdev);
4441 		return err;
4442 	}
4443 
4444 	/*
4445 	 * add_new_disk can be used once the array is assembled
4446 	 * to add "hot spares".  They must already have a superblock
4447 	 * written
4448 	 */
4449 	if (mddev->pers) {
4450 		int err;
4451 		if (!mddev->pers->hot_add_disk) {
4452 			printk(KERN_WARNING
4453 				"%s: personality does not support diskops!\n",
4454 			       mdname(mddev));
4455 			return -EINVAL;
4456 		}
4457 		if (mddev->persistent)
4458 			rdev = md_import_device(dev, mddev->major_version,
4459 						mddev->minor_version);
4460 		else
4461 			rdev = md_import_device(dev, -1, -1);
4462 		if (IS_ERR(rdev)) {
4463 			printk(KERN_WARNING
4464 				"md: md_import_device returned %ld\n",
4465 				PTR_ERR(rdev));
4466 			return PTR_ERR(rdev);
4467 		}
4468 		/* set save_raid_disk if appropriate */
4469 		if (!mddev->persistent) {
4470 			if (info->state & (1<<MD_DISK_SYNC)  &&
4471 			    info->raid_disk < mddev->raid_disks)
4472 				rdev->raid_disk = info->raid_disk;
4473 			else
4474 				rdev->raid_disk = -1;
4475 		} else
4476 			super_types[mddev->major_version].
4477 				validate_super(mddev, rdev);
4478 		rdev->saved_raid_disk = rdev->raid_disk;
4479 
4480 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
4481 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4482 			set_bit(WriteMostly, &rdev->flags);
4483 
4484 		rdev->raid_disk = -1;
4485 		err = bind_rdev_to_array(rdev, mddev);
4486 		if (!err && !mddev->pers->hot_remove_disk) {
4487 			/* If there is hot_add_disk but no hot_remove_disk
4488 			 * then added disks for geometry changes,
4489 			 * and should be added immediately.
4490 			 */
4491 			super_types[mddev->major_version].
4492 				validate_super(mddev, rdev);
4493 			err = mddev->pers->hot_add_disk(mddev, rdev);
4494 			if (err)
4495 				unbind_rdev_from_array(rdev);
4496 		}
4497 		if (err)
4498 			export_rdev(rdev);
4499 		else
4500 			sysfs_notify_dirent(rdev->sysfs_state);
4501 
4502 		md_update_sb(mddev, 1);
4503 		if (mddev->degraded)
4504 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4505 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4506 		md_wakeup_thread(mddev->thread);
4507 		return err;
4508 	}
4509 
4510 	/* otherwise, add_new_disk is only allowed
4511 	 * for major_version==0 superblocks
4512 	 */
4513 	if (mddev->major_version != 0) {
4514 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
4515 		       mdname(mddev));
4516 		return -EINVAL;
4517 	}
4518 
4519 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
4520 		int err;
4521 		rdev = md_import_device(dev, -1, 0);
4522 		if (IS_ERR(rdev)) {
4523 			printk(KERN_WARNING
4524 				"md: error, md_import_device() returned %ld\n",
4525 				PTR_ERR(rdev));
4526 			return PTR_ERR(rdev);
4527 		}
4528 		rdev->desc_nr = info->number;
4529 		if (info->raid_disk < mddev->raid_disks)
4530 			rdev->raid_disk = info->raid_disk;
4531 		else
4532 			rdev->raid_disk = -1;
4533 
4534 		if (rdev->raid_disk < mddev->raid_disks)
4535 			if (info->state & (1<<MD_DISK_SYNC))
4536 				set_bit(In_sync, &rdev->flags);
4537 
4538 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
4539 			set_bit(WriteMostly, &rdev->flags);
4540 
4541 		if (!mddev->persistent) {
4542 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
4543 			rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4544 		} else
4545 			rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4546 		rdev->size = calc_num_sectors(rdev, mddev->chunk_size) / 2;
4547 
4548 		err = bind_rdev_to_array(rdev, mddev);
4549 		if (err) {
4550 			export_rdev(rdev);
4551 			return err;
4552 		}
4553 	}
4554 
4555 	return 0;
4556 }
4557 
4558 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
4559 {
4560 	char b[BDEVNAME_SIZE];
4561 	mdk_rdev_t *rdev;
4562 
4563 	rdev = find_rdev(mddev, dev);
4564 	if (!rdev)
4565 		return -ENXIO;
4566 
4567 	if (rdev->raid_disk >= 0)
4568 		goto busy;
4569 
4570 	kick_rdev_from_array(rdev);
4571 	md_update_sb(mddev, 1);
4572 	md_new_event(mddev);
4573 
4574 	return 0;
4575 busy:
4576 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
4577 		bdevname(rdev->bdev,b), mdname(mddev));
4578 	return -EBUSY;
4579 }
4580 
4581 static int hot_add_disk(mddev_t * mddev, dev_t dev)
4582 {
4583 	char b[BDEVNAME_SIZE];
4584 	int err;
4585 	mdk_rdev_t *rdev;
4586 
4587 	if (!mddev->pers)
4588 		return -ENODEV;
4589 
4590 	if (mddev->major_version != 0) {
4591 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
4592 			" version-0 superblocks.\n",
4593 			mdname(mddev));
4594 		return -EINVAL;
4595 	}
4596 	if (!mddev->pers->hot_add_disk) {
4597 		printk(KERN_WARNING
4598 			"%s: personality does not support diskops!\n",
4599 			mdname(mddev));
4600 		return -EINVAL;
4601 	}
4602 
4603 	rdev = md_import_device(dev, -1, 0);
4604 	if (IS_ERR(rdev)) {
4605 		printk(KERN_WARNING
4606 			"md: error, md_import_device() returned %ld\n",
4607 			PTR_ERR(rdev));
4608 		return -EINVAL;
4609 	}
4610 
4611 	if (mddev->persistent)
4612 		rdev->sb_start = calc_dev_sboffset(rdev->bdev);
4613 	else
4614 		rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
4615 
4616 	rdev->size = calc_num_sectors(rdev, mddev->chunk_size) / 2;
4617 
4618 	if (test_bit(Faulty, &rdev->flags)) {
4619 		printk(KERN_WARNING
4620 			"md: can not hot-add faulty %s disk to %s!\n",
4621 			bdevname(rdev->bdev,b), mdname(mddev));
4622 		err = -EINVAL;
4623 		goto abort_export;
4624 	}
4625 	clear_bit(In_sync, &rdev->flags);
4626 	rdev->desc_nr = -1;
4627 	rdev->saved_raid_disk = -1;
4628 	err = bind_rdev_to_array(rdev, mddev);
4629 	if (err)
4630 		goto abort_export;
4631 
4632 	/*
4633 	 * The rest should better be atomic, we can have disk failures
4634 	 * noticed in interrupt contexts ...
4635 	 */
4636 
4637 	rdev->raid_disk = -1;
4638 
4639 	md_update_sb(mddev, 1);
4640 
4641 	/*
4642 	 * Kick recovery, maybe this spare has to be added to the
4643 	 * array immediately.
4644 	 */
4645 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4646 	md_wakeup_thread(mddev->thread);
4647 	md_new_event(mddev);
4648 	return 0;
4649 
4650 abort_export:
4651 	export_rdev(rdev);
4652 	return err;
4653 }
4654 
4655 static int set_bitmap_file(mddev_t *mddev, int fd)
4656 {
4657 	int err;
4658 
4659 	if (mddev->pers) {
4660 		if (!mddev->pers->quiesce)
4661 			return -EBUSY;
4662 		if (mddev->recovery || mddev->sync_thread)
4663 			return -EBUSY;
4664 		/* we should be able to change the bitmap.. */
4665 	}
4666 
4667 
4668 	if (fd >= 0) {
4669 		if (mddev->bitmap)
4670 			return -EEXIST; /* cannot add when bitmap is present */
4671 		mddev->bitmap_file = fget(fd);
4672 
4673 		if (mddev->bitmap_file == NULL) {
4674 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
4675 			       mdname(mddev));
4676 			return -EBADF;
4677 		}
4678 
4679 		err = deny_bitmap_write_access(mddev->bitmap_file);
4680 		if (err) {
4681 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
4682 			       mdname(mddev));
4683 			fput(mddev->bitmap_file);
4684 			mddev->bitmap_file = NULL;
4685 			return err;
4686 		}
4687 		mddev->bitmap_offset = 0; /* file overrides offset */
4688 	} else if (mddev->bitmap == NULL)
4689 		return -ENOENT; /* cannot remove what isn't there */
4690 	err = 0;
4691 	if (mddev->pers) {
4692 		mddev->pers->quiesce(mddev, 1);
4693 		if (fd >= 0)
4694 			err = bitmap_create(mddev);
4695 		if (fd < 0 || err) {
4696 			bitmap_destroy(mddev);
4697 			fd = -1; /* make sure to put the file */
4698 		}
4699 		mddev->pers->quiesce(mddev, 0);
4700 	}
4701 	if (fd < 0) {
4702 		if (mddev->bitmap_file) {
4703 			restore_bitmap_write_access(mddev->bitmap_file);
4704 			fput(mddev->bitmap_file);
4705 		}
4706 		mddev->bitmap_file = NULL;
4707 	}
4708 
4709 	return err;
4710 }
4711 
4712 /*
4713  * set_array_info is used two different ways
4714  * The original usage is when creating a new array.
4715  * In this usage, raid_disks is > 0 and it together with
4716  *  level, size, not_persistent,layout,chunksize determine the
4717  *  shape of the array.
4718  *  This will always create an array with a type-0.90.0 superblock.
4719  * The newer usage is when assembling an array.
4720  *  In this case raid_disks will be 0, and the major_version field is
4721  *  use to determine which style super-blocks are to be found on the devices.
4722  *  The minor and patch _version numbers are also kept incase the
4723  *  super_block handler wishes to interpret them.
4724  */
4725 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
4726 {
4727 
4728 	if (info->raid_disks == 0) {
4729 		/* just setting version number for superblock loading */
4730 		if (info->major_version < 0 ||
4731 		    info->major_version >= ARRAY_SIZE(super_types) ||
4732 		    super_types[info->major_version].name == NULL) {
4733 			/* maybe try to auto-load a module? */
4734 			printk(KERN_INFO
4735 				"md: superblock version %d not known\n",
4736 				info->major_version);
4737 			return -EINVAL;
4738 		}
4739 		mddev->major_version = info->major_version;
4740 		mddev->minor_version = info->minor_version;
4741 		mddev->patch_version = info->patch_version;
4742 		mddev->persistent = !info->not_persistent;
4743 		return 0;
4744 	}
4745 	mddev->major_version = MD_MAJOR_VERSION;
4746 	mddev->minor_version = MD_MINOR_VERSION;
4747 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
4748 	mddev->ctime         = get_seconds();
4749 
4750 	mddev->level         = info->level;
4751 	mddev->clevel[0]     = 0;
4752 	mddev->size          = info->size;
4753 	mddev->raid_disks    = info->raid_disks;
4754 	/* don't set md_minor, it is determined by which /dev/md* was
4755 	 * openned
4756 	 */
4757 	if (info->state & (1<<MD_SB_CLEAN))
4758 		mddev->recovery_cp = MaxSector;
4759 	else
4760 		mddev->recovery_cp = 0;
4761 	mddev->persistent    = ! info->not_persistent;
4762 	mddev->external	     = 0;
4763 
4764 	mddev->layout        = info->layout;
4765 	mddev->chunk_size    = info->chunk_size;
4766 
4767 	mddev->max_disks     = MD_SB_DISKS;
4768 
4769 	if (mddev->persistent)
4770 		mddev->flags         = 0;
4771 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
4772 
4773 	mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
4774 	mddev->bitmap_offset = 0;
4775 
4776 	mddev->reshape_position = MaxSector;
4777 
4778 	/*
4779 	 * Generate a 128 bit UUID
4780 	 */
4781 	get_random_bytes(mddev->uuid, 16);
4782 
4783 	mddev->new_level = mddev->level;
4784 	mddev->new_chunk = mddev->chunk_size;
4785 	mddev->new_layout = mddev->layout;
4786 	mddev->delta_disks = 0;
4787 
4788 	return 0;
4789 }
4790 
4791 static int update_size(mddev_t *mddev, sector_t num_sectors)
4792 {
4793 	mdk_rdev_t *rdev;
4794 	int rv;
4795 	int fit = (num_sectors == 0);
4796 
4797 	if (mddev->pers->resize == NULL)
4798 		return -EINVAL;
4799 	/* The "num_sectors" is the number of sectors of each device that
4800 	 * is used.  This can only make sense for arrays with redundancy.
4801 	 * linear and raid0 always use whatever space is available. We can only
4802 	 * consider changing this number if no resync or reconstruction is
4803 	 * happening, and if the new size is acceptable. It must fit before the
4804 	 * sb_start or, if that is <data_offset, it must fit before the size
4805 	 * of each device.  If num_sectors is zero, we find the largest size
4806 	 * that fits.
4807 
4808 	 */
4809 	if (mddev->sync_thread)
4810 		return -EBUSY;
4811 	if (mddev->bitmap)
4812 		/* Sorry, cannot grow a bitmap yet, just remove it,
4813 		 * grow, and re-add.
4814 		 */
4815 		return -EBUSY;
4816 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4817 		sector_t avail;
4818 		avail = rdev->size * 2;
4819 
4820 		if (fit && (num_sectors == 0 || num_sectors > avail))
4821 			num_sectors = avail;
4822 		if (avail < num_sectors)
4823 			return -ENOSPC;
4824 	}
4825 	rv = mddev->pers->resize(mddev, num_sectors);
4826 	if (!rv) {
4827 		struct block_device *bdev;
4828 
4829 		bdev = bdget_disk(mddev->gendisk, 0);
4830 		if (bdev) {
4831 			mutex_lock(&bdev->bd_inode->i_mutex);
4832 			i_size_write(bdev->bd_inode,
4833 				     (loff_t)mddev->array_sectors << 9);
4834 			mutex_unlock(&bdev->bd_inode->i_mutex);
4835 			bdput(bdev);
4836 		}
4837 	}
4838 	return rv;
4839 }
4840 
4841 static int update_raid_disks(mddev_t *mddev, int raid_disks)
4842 {
4843 	int rv;
4844 	/* change the number of raid disks */
4845 	if (mddev->pers->check_reshape == NULL)
4846 		return -EINVAL;
4847 	if (raid_disks <= 0 ||
4848 	    raid_disks >= mddev->max_disks)
4849 		return -EINVAL;
4850 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
4851 		return -EBUSY;
4852 	mddev->delta_disks = raid_disks - mddev->raid_disks;
4853 
4854 	rv = mddev->pers->check_reshape(mddev);
4855 	return rv;
4856 }
4857 
4858 
4859 /*
4860  * update_array_info is used to change the configuration of an
4861  * on-line array.
4862  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
4863  * fields in the info are checked against the array.
4864  * Any differences that cannot be handled will cause an error.
4865  * Normally, only one change can be managed at a time.
4866  */
4867 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
4868 {
4869 	int rv = 0;
4870 	int cnt = 0;
4871 	int state = 0;
4872 
4873 	/* calculate expected state,ignoring low bits */
4874 	if (mddev->bitmap && mddev->bitmap_offset)
4875 		state |= (1 << MD_SB_BITMAP_PRESENT);
4876 
4877 	if (mddev->major_version != info->major_version ||
4878 	    mddev->minor_version != info->minor_version ||
4879 /*	    mddev->patch_version != info->patch_version || */
4880 	    mddev->ctime         != info->ctime         ||
4881 	    mddev->level         != info->level         ||
4882 /*	    mddev->layout        != info->layout        || */
4883 	    !mddev->persistent	 != info->not_persistent||
4884 	    mddev->chunk_size    != info->chunk_size    ||
4885 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
4886 	    ((state^info->state) & 0xfffffe00)
4887 		)
4888 		return -EINVAL;
4889 	/* Check there is only one change */
4890 	if (info->size >= 0 && mddev->size != info->size) cnt++;
4891 	if (mddev->raid_disks != info->raid_disks) cnt++;
4892 	if (mddev->layout != info->layout) cnt++;
4893 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
4894 	if (cnt == 0) return 0;
4895 	if (cnt > 1) return -EINVAL;
4896 
4897 	if (mddev->layout != info->layout) {
4898 		/* Change layout
4899 		 * we don't need to do anything at the md level, the
4900 		 * personality will take care of it all.
4901 		 */
4902 		if (mddev->pers->reconfig == NULL)
4903 			return -EINVAL;
4904 		else
4905 			return mddev->pers->reconfig(mddev, info->layout, -1);
4906 	}
4907 	if (info->size >= 0 && mddev->size != info->size)
4908 		rv = update_size(mddev, (sector_t)info->size * 2);
4909 
4910 	if (mddev->raid_disks    != info->raid_disks)
4911 		rv = update_raid_disks(mddev, info->raid_disks);
4912 
4913 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
4914 		if (mddev->pers->quiesce == NULL)
4915 			return -EINVAL;
4916 		if (mddev->recovery || mddev->sync_thread)
4917 			return -EBUSY;
4918 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
4919 			/* add the bitmap */
4920 			if (mddev->bitmap)
4921 				return -EEXIST;
4922 			if (mddev->default_bitmap_offset == 0)
4923 				return -EINVAL;
4924 			mddev->bitmap_offset = mddev->default_bitmap_offset;
4925 			mddev->pers->quiesce(mddev, 1);
4926 			rv = bitmap_create(mddev);
4927 			if (rv)
4928 				bitmap_destroy(mddev);
4929 			mddev->pers->quiesce(mddev, 0);
4930 		} else {
4931 			/* remove the bitmap */
4932 			if (!mddev->bitmap)
4933 				return -ENOENT;
4934 			if (mddev->bitmap->file)
4935 				return -EINVAL;
4936 			mddev->pers->quiesce(mddev, 1);
4937 			bitmap_destroy(mddev);
4938 			mddev->pers->quiesce(mddev, 0);
4939 			mddev->bitmap_offset = 0;
4940 		}
4941 	}
4942 	md_update_sb(mddev, 1);
4943 	return rv;
4944 }
4945 
4946 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
4947 {
4948 	mdk_rdev_t *rdev;
4949 
4950 	if (mddev->pers == NULL)
4951 		return -ENODEV;
4952 
4953 	rdev = find_rdev(mddev, dev);
4954 	if (!rdev)
4955 		return -ENODEV;
4956 
4957 	md_error(mddev, rdev);
4958 	return 0;
4959 }
4960 
4961 /*
4962  * We have a problem here : there is no easy way to give a CHS
4963  * virtual geometry. We currently pretend that we have a 2 heads
4964  * 4 sectors (with a BIG number of cylinders...). This drives
4965  * dosfs just mad... ;-)
4966  */
4967 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
4968 {
4969 	mddev_t *mddev = bdev->bd_disk->private_data;
4970 
4971 	geo->heads = 2;
4972 	geo->sectors = 4;
4973 	geo->cylinders = get_capacity(mddev->gendisk) / 8;
4974 	return 0;
4975 }
4976 
4977 static int md_ioctl(struct block_device *bdev, fmode_t mode,
4978 			unsigned int cmd, unsigned long arg)
4979 {
4980 	int err = 0;
4981 	void __user *argp = (void __user *)arg;
4982 	mddev_t *mddev = NULL;
4983 
4984 	if (!capable(CAP_SYS_ADMIN))
4985 		return -EACCES;
4986 
4987 	/*
4988 	 * Commands dealing with the RAID driver but not any
4989 	 * particular array:
4990 	 */
4991 	switch (cmd)
4992 	{
4993 		case RAID_VERSION:
4994 			err = get_version(argp);
4995 			goto done;
4996 
4997 		case PRINT_RAID_DEBUG:
4998 			err = 0;
4999 			md_print_devices();
5000 			goto done;
5001 
5002 #ifndef MODULE
5003 		case RAID_AUTORUN:
5004 			err = 0;
5005 			autostart_arrays(arg);
5006 			goto done;
5007 #endif
5008 		default:;
5009 	}
5010 
5011 	/*
5012 	 * Commands creating/starting a new array:
5013 	 */
5014 
5015 	mddev = bdev->bd_disk->private_data;
5016 
5017 	if (!mddev) {
5018 		BUG();
5019 		goto abort;
5020 	}
5021 
5022 	err = mddev_lock(mddev);
5023 	if (err) {
5024 		printk(KERN_INFO
5025 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
5026 			err, cmd);
5027 		goto abort;
5028 	}
5029 
5030 	switch (cmd)
5031 	{
5032 		case SET_ARRAY_INFO:
5033 			{
5034 				mdu_array_info_t info;
5035 				if (!arg)
5036 					memset(&info, 0, sizeof(info));
5037 				else if (copy_from_user(&info, argp, sizeof(info))) {
5038 					err = -EFAULT;
5039 					goto abort_unlock;
5040 				}
5041 				if (mddev->pers) {
5042 					err = update_array_info(mddev, &info);
5043 					if (err) {
5044 						printk(KERN_WARNING "md: couldn't update"
5045 						       " array info. %d\n", err);
5046 						goto abort_unlock;
5047 					}
5048 					goto done_unlock;
5049 				}
5050 				if (!list_empty(&mddev->disks)) {
5051 					printk(KERN_WARNING
5052 					       "md: array %s already has disks!\n",
5053 					       mdname(mddev));
5054 					err = -EBUSY;
5055 					goto abort_unlock;
5056 				}
5057 				if (mddev->raid_disks) {
5058 					printk(KERN_WARNING
5059 					       "md: array %s already initialised!\n",
5060 					       mdname(mddev));
5061 					err = -EBUSY;
5062 					goto abort_unlock;
5063 				}
5064 				err = set_array_info(mddev, &info);
5065 				if (err) {
5066 					printk(KERN_WARNING "md: couldn't set"
5067 					       " array info. %d\n", err);
5068 					goto abort_unlock;
5069 				}
5070 			}
5071 			goto done_unlock;
5072 
5073 		default:;
5074 	}
5075 
5076 	/*
5077 	 * Commands querying/configuring an existing array:
5078 	 */
5079 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
5080 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
5081 	if ((!mddev->raid_disks && !mddev->external)
5082 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
5083 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
5084 	    && cmd != GET_BITMAP_FILE) {
5085 		err = -ENODEV;
5086 		goto abort_unlock;
5087 	}
5088 
5089 	/*
5090 	 * Commands even a read-only array can execute:
5091 	 */
5092 	switch (cmd)
5093 	{
5094 		case GET_ARRAY_INFO:
5095 			err = get_array_info(mddev, argp);
5096 			goto done_unlock;
5097 
5098 		case GET_BITMAP_FILE:
5099 			err = get_bitmap_file(mddev, argp);
5100 			goto done_unlock;
5101 
5102 		case GET_DISK_INFO:
5103 			err = get_disk_info(mddev, argp);
5104 			goto done_unlock;
5105 
5106 		case RESTART_ARRAY_RW:
5107 			err = restart_array(mddev);
5108 			goto done_unlock;
5109 
5110 		case STOP_ARRAY:
5111 			err = do_md_stop(mddev, 0, 1);
5112 			goto done_unlock;
5113 
5114 		case STOP_ARRAY_RO:
5115 			err = do_md_stop(mddev, 1, 1);
5116 			goto done_unlock;
5117 
5118 	}
5119 
5120 	/*
5121 	 * The remaining ioctls are changing the state of the
5122 	 * superblock, so we do not allow them on read-only arrays.
5123 	 * However non-MD ioctls (e.g. get-size) will still come through
5124 	 * here and hit the 'default' below, so only disallow
5125 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
5126 	 */
5127 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
5128 		if (mddev->ro == 2) {
5129 			mddev->ro = 0;
5130 			sysfs_notify_dirent(mddev->sysfs_state);
5131 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5132 			md_wakeup_thread(mddev->thread);
5133 		} else {
5134 			err = -EROFS;
5135 			goto abort_unlock;
5136 		}
5137 	}
5138 
5139 	switch (cmd)
5140 	{
5141 		case ADD_NEW_DISK:
5142 		{
5143 			mdu_disk_info_t info;
5144 			if (copy_from_user(&info, argp, sizeof(info)))
5145 				err = -EFAULT;
5146 			else
5147 				err = add_new_disk(mddev, &info);
5148 			goto done_unlock;
5149 		}
5150 
5151 		case HOT_REMOVE_DISK:
5152 			err = hot_remove_disk(mddev, new_decode_dev(arg));
5153 			goto done_unlock;
5154 
5155 		case HOT_ADD_DISK:
5156 			err = hot_add_disk(mddev, new_decode_dev(arg));
5157 			goto done_unlock;
5158 
5159 		case SET_DISK_FAULTY:
5160 			err = set_disk_faulty(mddev, new_decode_dev(arg));
5161 			goto done_unlock;
5162 
5163 		case RUN_ARRAY:
5164 			err = do_md_run(mddev);
5165 			goto done_unlock;
5166 
5167 		case SET_BITMAP_FILE:
5168 			err = set_bitmap_file(mddev, (int)arg);
5169 			goto done_unlock;
5170 
5171 		default:
5172 			err = -EINVAL;
5173 			goto abort_unlock;
5174 	}
5175 
5176 done_unlock:
5177 abort_unlock:
5178 	if (mddev->hold_active == UNTIL_IOCTL &&
5179 	    err != -EINVAL)
5180 		mddev->hold_active = 0;
5181 	mddev_unlock(mddev);
5182 
5183 	return err;
5184 done:
5185 	if (err)
5186 		MD_BUG();
5187 abort:
5188 	return err;
5189 }
5190 
5191 static int md_open(struct block_device *bdev, fmode_t mode)
5192 {
5193 	/*
5194 	 * Succeed if we can lock the mddev, which confirms that
5195 	 * it isn't being stopped right now.
5196 	 */
5197 	mddev_t *mddev = mddev_find(bdev->bd_dev);
5198 	int err;
5199 
5200 	if (mddev->gendisk != bdev->bd_disk) {
5201 		/* we are racing with mddev_put which is discarding this
5202 		 * bd_disk.
5203 		 */
5204 		mddev_put(mddev);
5205 		/* Wait until bdev->bd_disk is definitely gone */
5206 		flush_scheduled_work();
5207 		/* Then retry the open from the top */
5208 		return -ERESTARTSYS;
5209 	}
5210 	BUG_ON(mddev != bdev->bd_disk->private_data);
5211 
5212 	if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
5213 		goto out;
5214 
5215 	err = 0;
5216 	atomic_inc(&mddev->openers);
5217 	mddev_unlock(mddev);
5218 
5219 	check_disk_change(bdev);
5220  out:
5221 	return err;
5222 }
5223 
5224 static int md_release(struct gendisk *disk, fmode_t mode)
5225 {
5226  	mddev_t *mddev = disk->private_data;
5227 
5228 	BUG_ON(!mddev);
5229 	atomic_dec(&mddev->openers);
5230 	mddev_put(mddev);
5231 
5232 	return 0;
5233 }
5234 
5235 static int md_media_changed(struct gendisk *disk)
5236 {
5237 	mddev_t *mddev = disk->private_data;
5238 
5239 	return mddev->changed;
5240 }
5241 
5242 static int md_revalidate(struct gendisk *disk)
5243 {
5244 	mddev_t *mddev = disk->private_data;
5245 
5246 	mddev->changed = 0;
5247 	return 0;
5248 }
5249 static struct block_device_operations md_fops =
5250 {
5251 	.owner		= THIS_MODULE,
5252 	.open		= md_open,
5253 	.release	= md_release,
5254 	.locked_ioctl	= md_ioctl,
5255 	.getgeo		= md_getgeo,
5256 	.media_changed	= md_media_changed,
5257 	.revalidate_disk= md_revalidate,
5258 };
5259 
5260 static int md_thread(void * arg)
5261 {
5262 	mdk_thread_t *thread = arg;
5263 
5264 	/*
5265 	 * md_thread is a 'system-thread', it's priority should be very
5266 	 * high. We avoid resource deadlocks individually in each
5267 	 * raid personality. (RAID5 does preallocation) We also use RR and
5268 	 * the very same RT priority as kswapd, thus we will never get
5269 	 * into a priority inversion deadlock.
5270 	 *
5271 	 * we definitely have to have equal or higher priority than
5272 	 * bdflush, otherwise bdflush will deadlock if there are too
5273 	 * many dirty RAID5 blocks.
5274 	 */
5275 
5276 	allow_signal(SIGKILL);
5277 	while (!kthread_should_stop()) {
5278 
5279 		/* We need to wait INTERRUPTIBLE so that
5280 		 * we don't add to the load-average.
5281 		 * That means we need to be sure no signals are
5282 		 * pending
5283 		 */
5284 		if (signal_pending(current))
5285 			flush_signals(current);
5286 
5287 		wait_event_interruptible_timeout
5288 			(thread->wqueue,
5289 			 test_bit(THREAD_WAKEUP, &thread->flags)
5290 			 || kthread_should_stop(),
5291 			 thread->timeout);
5292 
5293 		clear_bit(THREAD_WAKEUP, &thread->flags);
5294 
5295 		thread->run(thread->mddev);
5296 	}
5297 
5298 	return 0;
5299 }
5300 
5301 void md_wakeup_thread(mdk_thread_t *thread)
5302 {
5303 	if (thread) {
5304 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
5305 		set_bit(THREAD_WAKEUP, &thread->flags);
5306 		wake_up(&thread->wqueue);
5307 	}
5308 }
5309 
5310 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
5311 				 const char *name)
5312 {
5313 	mdk_thread_t *thread;
5314 
5315 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
5316 	if (!thread)
5317 		return NULL;
5318 
5319 	init_waitqueue_head(&thread->wqueue);
5320 
5321 	thread->run = run;
5322 	thread->mddev = mddev;
5323 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
5324 	thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
5325 	if (IS_ERR(thread->tsk)) {
5326 		kfree(thread);
5327 		return NULL;
5328 	}
5329 	return thread;
5330 }
5331 
5332 void md_unregister_thread(mdk_thread_t *thread)
5333 {
5334 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
5335 
5336 	kthread_stop(thread->tsk);
5337 	kfree(thread);
5338 }
5339 
5340 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
5341 {
5342 	if (!mddev) {
5343 		MD_BUG();
5344 		return;
5345 	}
5346 
5347 	if (!rdev || test_bit(Faulty, &rdev->flags))
5348 		return;
5349 
5350 	if (mddev->external)
5351 		set_bit(Blocked, &rdev->flags);
5352 /*
5353 	dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
5354 		mdname(mddev),
5355 		MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
5356 		__builtin_return_address(0),__builtin_return_address(1),
5357 		__builtin_return_address(2),__builtin_return_address(3));
5358 */
5359 	if (!mddev->pers)
5360 		return;
5361 	if (!mddev->pers->error_handler)
5362 		return;
5363 	mddev->pers->error_handler(mddev,rdev);
5364 	if (mddev->degraded)
5365 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5366 	set_bit(StateChanged, &rdev->flags);
5367 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5368 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5369 	md_wakeup_thread(mddev->thread);
5370 	md_new_event_inintr(mddev);
5371 }
5372 
5373 /* seq_file implementation /proc/mdstat */
5374 
5375 static void status_unused(struct seq_file *seq)
5376 {
5377 	int i = 0;
5378 	mdk_rdev_t *rdev;
5379 
5380 	seq_printf(seq, "unused devices: ");
5381 
5382 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
5383 		char b[BDEVNAME_SIZE];
5384 		i++;
5385 		seq_printf(seq, "%s ",
5386 			      bdevname(rdev->bdev,b));
5387 	}
5388 	if (!i)
5389 		seq_printf(seq, "<none>");
5390 
5391 	seq_printf(seq, "\n");
5392 }
5393 
5394 
5395 static void status_resync(struct seq_file *seq, mddev_t * mddev)
5396 {
5397 	sector_t max_blocks, resync, res;
5398 	unsigned long dt, db, rt;
5399 	int scale;
5400 	unsigned int per_milli;
5401 
5402 	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
5403 
5404 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
5405 		max_blocks = mddev->resync_max_sectors >> 1;
5406 	else
5407 		max_blocks = mddev->size;
5408 
5409 	/*
5410 	 * Should not happen.
5411 	 */
5412 	if (!max_blocks) {
5413 		MD_BUG();
5414 		return;
5415 	}
5416 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
5417 	 * in a sector_t, and (max_blocks>>scale) will fit in a
5418 	 * u32, as those are the requirements for sector_div.
5419 	 * Thus 'scale' must be at least 10
5420 	 */
5421 	scale = 10;
5422 	if (sizeof(sector_t) > sizeof(unsigned long)) {
5423 		while ( max_blocks/2 > (1ULL<<(scale+32)))
5424 			scale++;
5425 	}
5426 	res = (resync>>scale)*1000;
5427 	sector_div(res, (u32)((max_blocks>>scale)+1));
5428 
5429 	per_milli = res;
5430 	{
5431 		int i, x = per_milli/50, y = 20-x;
5432 		seq_printf(seq, "[");
5433 		for (i = 0; i < x; i++)
5434 			seq_printf(seq, "=");
5435 		seq_printf(seq, ">");
5436 		for (i = 0; i < y; i++)
5437 			seq_printf(seq, ".");
5438 		seq_printf(seq, "] ");
5439 	}
5440 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
5441 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
5442 		    "reshape" :
5443 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
5444 		     "check" :
5445 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
5446 		      "resync" : "recovery"))),
5447 		   per_milli/10, per_milli % 10,
5448 		   (unsigned long long) resync,
5449 		   (unsigned long long) max_blocks);
5450 
5451 	/*
5452 	 * We do not want to overflow, so the order of operands and
5453 	 * the * 100 / 100 trick are important. We do a +1 to be
5454 	 * safe against division by zero. We only estimate anyway.
5455 	 *
5456 	 * dt: time from mark until now
5457 	 * db: blocks written from mark until now
5458 	 * rt: remaining time
5459 	 */
5460 	dt = ((jiffies - mddev->resync_mark) / HZ);
5461 	if (!dt) dt++;
5462 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
5463 		- mddev->resync_mark_cnt;
5464 	rt = (dt * ((unsigned long)(max_blocks-resync) / (db/2/100+1)))/100;
5465 
5466 	seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
5467 
5468 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
5469 }
5470 
5471 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
5472 {
5473 	struct list_head *tmp;
5474 	loff_t l = *pos;
5475 	mddev_t *mddev;
5476 
5477 	if (l >= 0x10000)
5478 		return NULL;
5479 	if (!l--)
5480 		/* header */
5481 		return (void*)1;
5482 
5483 	spin_lock(&all_mddevs_lock);
5484 	list_for_each(tmp,&all_mddevs)
5485 		if (!l--) {
5486 			mddev = list_entry(tmp, mddev_t, all_mddevs);
5487 			mddev_get(mddev);
5488 			spin_unlock(&all_mddevs_lock);
5489 			return mddev;
5490 		}
5491 	spin_unlock(&all_mddevs_lock);
5492 	if (!l--)
5493 		return (void*)2;/* tail */
5494 	return NULL;
5495 }
5496 
5497 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
5498 {
5499 	struct list_head *tmp;
5500 	mddev_t *next_mddev, *mddev = v;
5501 
5502 	++*pos;
5503 	if (v == (void*)2)
5504 		return NULL;
5505 
5506 	spin_lock(&all_mddevs_lock);
5507 	if (v == (void*)1)
5508 		tmp = all_mddevs.next;
5509 	else
5510 		tmp = mddev->all_mddevs.next;
5511 	if (tmp != &all_mddevs)
5512 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
5513 	else {
5514 		next_mddev = (void*)2;
5515 		*pos = 0x10000;
5516 	}
5517 	spin_unlock(&all_mddevs_lock);
5518 
5519 	if (v != (void*)1)
5520 		mddev_put(mddev);
5521 	return next_mddev;
5522 
5523 }
5524 
5525 static void md_seq_stop(struct seq_file *seq, void *v)
5526 {
5527 	mddev_t *mddev = v;
5528 
5529 	if (mddev && v != (void*)1 && v != (void*)2)
5530 		mddev_put(mddev);
5531 }
5532 
5533 struct mdstat_info {
5534 	int event;
5535 };
5536 
5537 static int md_seq_show(struct seq_file *seq, void *v)
5538 {
5539 	mddev_t *mddev = v;
5540 	sector_t size;
5541 	mdk_rdev_t *rdev;
5542 	struct mdstat_info *mi = seq->private;
5543 	struct bitmap *bitmap;
5544 
5545 	if (v == (void*)1) {
5546 		struct mdk_personality *pers;
5547 		seq_printf(seq, "Personalities : ");
5548 		spin_lock(&pers_lock);
5549 		list_for_each_entry(pers, &pers_list, list)
5550 			seq_printf(seq, "[%s] ", pers->name);
5551 
5552 		spin_unlock(&pers_lock);
5553 		seq_printf(seq, "\n");
5554 		mi->event = atomic_read(&md_event_count);
5555 		return 0;
5556 	}
5557 	if (v == (void*)2) {
5558 		status_unused(seq);
5559 		return 0;
5560 	}
5561 
5562 	if (mddev_lock(mddev) < 0)
5563 		return -EINTR;
5564 
5565 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
5566 		seq_printf(seq, "%s : %sactive", mdname(mddev),
5567 						mddev->pers ? "" : "in");
5568 		if (mddev->pers) {
5569 			if (mddev->ro==1)
5570 				seq_printf(seq, " (read-only)");
5571 			if (mddev->ro==2)
5572 				seq_printf(seq, " (auto-read-only)");
5573 			seq_printf(seq, " %s", mddev->pers->name);
5574 		}
5575 
5576 		size = 0;
5577 		list_for_each_entry(rdev, &mddev->disks, same_set) {
5578 			char b[BDEVNAME_SIZE];
5579 			seq_printf(seq, " %s[%d]",
5580 				bdevname(rdev->bdev,b), rdev->desc_nr);
5581 			if (test_bit(WriteMostly, &rdev->flags))
5582 				seq_printf(seq, "(W)");
5583 			if (test_bit(Faulty, &rdev->flags)) {
5584 				seq_printf(seq, "(F)");
5585 				continue;
5586 			} else if (rdev->raid_disk < 0)
5587 				seq_printf(seq, "(S)"); /* spare */
5588 			size += rdev->size;
5589 		}
5590 
5591 		if (!list_empty(&mddev->disks)) {
5592 			if (mddev->pers)
5593 				seq_printf(seq, "\n      %llu blocks",
5594 					   (unsigned long long)
5595 					   mddev->array_sectors / 2);
5596 			else
5597 				seq_printf(seq, "\n      %llu blocks",
5598 					   (unsigned long long)size);
5599 		}
5600 		if (mddev->persistent) {
5601 			if (mddev->major_version != 0 ||
5602 			    mddev->minor_version != 90) {
5603 				seq_printf(seq," super %d.%d",
5604 					   mddev->major_version,
5605 					   mddev->minor_version);
5606 			}
5607 		} else if (mddev->external)
5608 			seq_printf(seq, " super external:%s",
5609 				   mddev->metadata_type);
5610 		else
5611 			seq_printf(seq, " super non-persistent");
5612 
5613 		if (mddev->pers) {
5614 			mddev->pers->status(seq, mddev);
5615 	 		seq_printf(seq, "\n      ");
5616 			if (mddev->pers->sync_request) {
5617 				if (mddev->curr_resync > 2) {
5618 					status_resync(seq, mddev);
5619 					seq_printf(seq, "\n      ");
5620 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
5621 					seq_printf(seq, "\tresync=DELAYED\n      ");
5622 				else if (mddev->recovery_cp < MaxSector)
5623 					seq_printf(seq, "\tresync=PENDING\n      ");
5624 			}
5625 		} else
5626 			seq_printf(seq, "\n       ");
5627 
5628 		if ((bitmap = mddev->bitmap)) {
5629 			unsigned long chunk_kb;
5630 			unsigned long flags;
5631 			spin_lock_irqsave(&bitmap->lock, flags);
5632 			chunk_kb = bitmap->chunksize >> 10;
5633 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
5634 				"%lu%s chunk",
5635 				bitmap->pages - bitmap->missing_pages,
5636 				bitmap->pages,
5637 				(bitmap->pages - bitmap->missing_pages)
5638 					<< (PAGE_SHIFT - 10),
5639 				chunk_kb ? chunk_kb : bitmap->chunksize,
5640 				chunk_kb ? "KB" : "B");
5641 			if (bitmap->file) {
5642 				seq_printf(seq, ", file: ");
5643 				seq_path(seq, &bitmap->file->f_path, " \t\n");
5644 			}
5645 
5646 			seq_printf(seq, "\n");
5647 			spin_unlock_irqrestore(&bitmap->lock, flags);
5648 		}
5649 
5650 		seq_printf(seq, "\n");
5651 	}
5652 	mddev_unlock(mddev);
5653 
5654 	return 0;
5655 }
5656 
5657 static struct seq_operations md_seq_ops = {
5658 	.start  = md_seq_start,
5659 	.next   = md_seq_next,
5660 	.stop   = md_seq_stop,
5661 	.show   = md_seq_show,
5662 };
5663 
5664 static int md_seq_open(struct inode *inode, struct file *file)
5665 {
5666 	int error;
5667 	struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
5668 	if (mi == NULL)
5669 		return -ENOMEM;
5670 
5671 	error = seq_open(file, &md_seq_ops);
5672 	if (error)
5673 		kfree(mi);
5674 	else {
5675 		struct seq_file *p = file->private_data;
5676 		p->private = mi;
5677 		mi->event = atomic_read(&md_event_count);
5678 	}
5679 	return error;
5680 }
5681 
5682 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
5683 {
5684 	struct seq_file *m = filp->private_data;
5685 	struct mdstat_info *mi = m->private;
5686 	int mask;
5687 
5688 	poll_wait(filp, &md_event_waiters, wait);
5689 
5690 	/* always allow read */
5691 	mask = POLLIN | POLLRDNORM;
5692 
5693 	if (mi->event != atomic_read(&md_event_count))
5694 		mask |= POLLERR | POLLPRI;
5695 	return mask;
5696 }
5697 
5698 static const struct file_operations md_seq_fops = {
5699 	.owner		= THIS_MODULE,
5700 	.open           = md_seq_open,
5701 	.read           = seq_read,
5702 	.llseek         = seq_lseek,
5703 	.release	= seq_release_private,
5704 	.poll		= mdstat_poll,
5705 };
5706 
5707 int register_md_personality(struct mdk_personality *p)
5708 {
5709 	spin_lock(&pers_lock);
5710 	list_add_tail(&p->list, &pers_list);
5711 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
5712 	spin_unlock(&pers_lock);
5713 	return 0;
5714 }
5715 
5716 int unregister_md_personality(struct mdk_personality *p)
5717 {
5718 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
5719 	spin_lock(&pers_lock);
5720 	list_del_init(&p->list);
5721 	spin_unlock(&pers_lock);
5722 	return 0;
5723 }
5724 
5725 static int is_mddev_idle(mddev_t *mddev)
5726 {
5727 	mdk_rdev_t * rdev;
5728 	int idle;
5729 	long curr_events;
5730 
5731 	idle = 1;
5732 	rcu_read_lock();
5733 	rdev_for_each_rcu(rdev, mddev) {
5734 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
5735 		curr_events = part_stat_read(&disk->part0, sectors[0]) +
5736 				part_stat_read(&disk->part0, sectors[1]) -
5737 				atomic_read(&disk->sync_io);
5738 		/* sync IO will cause sync_io to increase before the disk_stats
5739 		 * as sync_io is counted when a request starts, and
5740 		 * disk_stats is counted when it completes.
5741 		 * So resync activity will cause curr_events to be smaller than
5742 		 * when there was no such activity.
5743 		 * non-sync IO will cause disk_stat to increase without
5744 		 * increasing sync_io so curr_events will (eventually)
5745 		 * be larger than it was before.  Once it becomes
5746 		 * substantially larger, the test below will cause
5747 		 * the array to appear non-idle, and resync will slow
5748 		 * down.
5749 		 * If there is a lot of outstanding resync activity when
5750 		 * we set last_event to curr_events, then all that activity
5751 		 * completing might cause the array to appear non-idle
5752 		 * and resync will be slowed down even though there might
5753 		 * not have been non-resync activity.  This will only
5754 		 * happen once though.  'last_events' will soon reflect
5755 		 * the state where there is little or no outstanding
5756 		 * resync requests, and further resync activity will
5757 		 * always make curr_events less than last_events.
5758 		 *
5759 		 */
5760 		if (curr_events - rdev->last_events > 4096) {
5761 			rdev->last_events = curr_events;
5762 			idle = 0;
5763 		}
5764 	}
5765 	rcu_read_unlock();
5766 	return idle;
5767 }
5768 
5769 void md_done_sync(mddev_t *mddev, int blocks, int ok)
5770 {
5771 	/* another "blocks" (512byte) blocks have been synced */
5772 	atomic_sub(blocks, &mddev->recovery_active);
5773 	wake_up(&mddev->recovery_wait);
5774 	if (!ok) {
5775 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5776 		md_wakeup_thread(mddev->thread);
5777 		// stop recovery, signal do_sync ....
5778 	}
5779 }
5780 
5781 
5782 /* md_write_start(mddev, bi)
5783  * If we need to update some array metadata (e.g. 'active' flag
5784  * in superblock) before writing, schedule a superblock update
5785  * and wait for it to complete.
5786  */
5787 void md_write_start(mddev_t *mddev, struct bio *bi)
5788 {
5789 	int did_change = 0;
5790 	if (bio_data_dir(bi) != WRITE)
5791 		return;
5792 
5793 	BUG_ON(mddev->ro == 1);
5794 	if (mddev->ro == 2) {
5795 		/* need to switch to read/write */
5796 		mddev->ro = 0;
5797 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5798 		md_wakeup_thread(mddev->thread);
5799 		md_wakeup_thread(mddev->sync_thread);
5800 		did_change = 1;
5801 	}
5802 	atomic_inc(&mddev->writes_pending);
5803 	if (mddev->safemode == 1)
5804 		mddev->safemode = 0;
5805 	if (mddev->in_sync) {
5806 		spin_lock_irq(&mddev->write_lock);
5807 		if (mddev->in_sync) {
5808 			mddev->in_sync = 0;
5809 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
5810 			md_wakeup_thread(mddev->thread);
5811 			did_change = 1;
5812 		}
5813 		spin_unlock_irq(&mddev->write_lock);
5814 	}
5815 	if (did_change)
5816 		sysfs_notify_dirent(mddev->sysfs_state);
5817 	wait_event(mddev->sb_wait,
5818 		   !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
5819 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
5820 }
5821 
5822 void md_write_end(mddev_t *mddev)
5823 {
5824 	if (atomic_dec_and_test(&mddev->writes_pending)) {
5825 		if (mddev->safemode == 2)
5826 			md_wakeup_thread(mddev->thread);
5827 		else if (mddev->safemode_delay)
5828 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
5829 	}
5830 }
5831 
5832 /* md_allow_write(mddev)
5833  * Calling this ensures that the array is marked 'active' so that writes
5834  * may proceed without blocking.  It is important to call this before
5835  * attempting a GFP_KERNEL allocation while holding the mddev lock.
5836  * Must be called with mddev_lock held.
5837  *
5838  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
5839  * is dropped, so return -EAGAIN after notifying userspace.
5840  */
5841 int md_allow_write(mddev_t *mddev)
5842 {
5843 	if (!mddev->pers)
5844 		return 0;
5845 	if (mddev->ro)
5846 		return 0;
5847 	if (!mddev->pers->sync_request)
5848 		return 0;
5849 
5850 	spin_lock_irq(&mddev->write_lock);
5851 	if (mddev->in_sync) {
5852 		mddev->in_sync = 0;
5853 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
5854 		if (mddev->safemode_delay &&
5855 		    mddev->safemode == 0)
5856 			mddev->safemode = 1;
5857 		spin_unlock_irq(&mddev->write_lock);
5858 		md_update_sb(mddev, 0);
5859 		sysfs_notify_dirent(mddev->sysfs_state);
5860 	} else
5861 		spin_unlock_irq(&mddev->write_lock);
5862 
5863 	if (test_bit(MD_CHANGE_CLEAN, &mddev->flags))
5864 		return -EAGAIN;
5865 	else
5866 		return 0;
5867 }
5868 EXPORT_SYMBOL_GPL(md_allow_write);
5869 
5870 #define SYNC_MARKS	10
5871 #define	SYNC_MARK_STEP	(3*HZ)
5872 void md_do_sync(mddev_t *mddev)
5873 {
5874 	mddev_t *mddev2;
5875 	unsigned int currspeed = 0,
5876 		 window;
5877 	sector_t max_sectors,j, io_sectors;
5878 	unsigned long mark[SYNC_MARKS];
5879 	sector_t mark_cnt[SYNC_MARKS];
5880 	int last_mark,m;
5881 	struct list_head *tmp;
5882 	sector_t last_check;
5883 	int skipped = 0;
5884 	mdk_rdev_t *rdev;
5885 	char *desc;
5886 
5887 	/* just incase thread restarts... */
5888 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
5889 		return;
5890 	if (mddev->ro) /* never try to sync a read-only array */
5891 		return;
5892 
5893 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5894 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
5895 			desc = "data-check";
5896 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
5897 			desc = "requested-resync";
5898 		else
5899 			desc = "resync";
5900 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5901 		desc = "reshape";
5902 	else
5903 		desc = "recovery";
5904 
5905 	/* we overload curr_resync somewhat here.
5906 	 * 0 == not engaged in resync at all
5907 	 * 2 == checking that there is no conflict with another sync
5908 	 * 1 == like 2, but have yielded to allow conflicting resync to
5909 	 *		commense
5910 	 * other == active in resync - this many blocks
5911 	 *
5912 	 * Before starting a resync we must have set curr_resync to
5913 	 * 2, and then checked that every "conflicting" array has curr_resync
5914 	 * less than ours.  When we find one that is the same or higher
5915 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
5916 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
5917 	 * This will mean we have to start checking from the beginning again.
5918 	 *
5919 	 */
5920 
5921 	do {
5922 		mddev->curr_resync = 2;
5923 
5924 	try_again:
5925 		if (kthread_should_stop()) {
5926 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5927 			goto skip;
5928 		}
5929 		for_each_mddev(mddev2, tmp) {
5930 			if (mddev2 == mddev)
5931 				continue;
5932 			if (!mddev->parallel_resync
5933 			&&  mddev2->curr_resync
5934 			&&  match_mddev_units(mddev, mddev2)) {
5935 				DEFINE_WAIT(wq);
5936 				if (mddev < mddev2 && mddev->curr_resync == 2) {
5937 					/* arbitrarily yield */
5938 					mddev->curr_resync = 1;
5939 					wake_up(&resync_wait);
5940 				}
5941 				if (mddev > mddev2 && mddev->curr_resync == 1)
5942 					/* no need to wait here, we can wait the next
5943 					 * time 'round when curr_resync == 2
5944 					 */
5945 					continue;
5946 				/* We need to wait 'interruptible' so as not to
5947 				 * contribute to the load average, and not to
5948 				 * be caught by 'softlockup'
5949 				 */
5950 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
5951 				if (!kthread_should_stop() &&
5952 				    mddev2->curr_resync >= mddev->curr_resync) {
5953 					printk(KERN_INFO "md: delaying %s of %s"
5954 					       " until %s has finished (they"
5955 					       " share one or more physical units)\n",
5956 					       desc, mdname(mddev), mdname(mddev2));
5957 					mddev_put(mddev2);
5958 					if (signal_pending(current))
5959 						flush_signals(current);
5960 					schedule();
5961 					finish_wait(&resync_wait, &wq);
5962 					goto try_again;
5963 				}
5964 				finish_wait(&resync_wait, &wq);
5965 			}
5966 		}
5967 	} while (mddev->curr_resync < 2);
5968 
5969 	j = 0;
5970 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5971 		/* resync follows the size requested by the personality,
5972 		 * which defaults to physical size, but can be virtual size
5973 		 */
5974 		max_sectors = mddev->resync_max_sectors;
5975 		mddev->resync_mismatches = 0;
5976 		/* we don't use the checkpoint if there's a bitmap */
5977 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
5978 			j = mddev->resync_min;
5979 		else if (!mddev->bitmap)
5980 			j = mddev->recovery_cp;
5981 
5982 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5983 		max_sectors = mddev->size << 1;
5984 	else {
5985 		/* recovery follows the physical size of devices */
5986 		max_sectors = mddev->size << 1;
5987 		j = MaxSector;
5988 		list_for_each_entry(rdev, &mddev->disks, same_set)
5989 			if (rdev->raid_disk >= 0 &&
5990 			    !test_bit(Faulty, &rdev->flags) &&
5991 			    !test_bit(In_sync, &rdev->flags) &&
5992 			    rdev->recovery_offset < j)
5993 				j = rdev->recovery_offset;
5994 	}
5995 
5996 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
5997 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
5998 		" %d KB/sec/disk.\n", speed_min(mddev));
5999 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
6000 	       "(but not more than %d KB/sec) for %s.\n",
6001 	       speed_max(mddev), desc);
6002 
6003 	is_mddev_idle(mddev); /* this also initializes IO event counters */
6004 
6005 	io_sectors = 0;
6006 	for (m = 0; m < SYNC_MARKS; m++) {
6007 		mark[m] = jiffies;
6008 		mark_cnt[m] = io_sectors;
6009 	}
6010 	last_mark = 0;
6011 	mddev->resync_mark = mark[last_mark];
6012 	mddev->resync_mark_cnt = mark_cnt[last_mark];
6013 
6014 	/*
6015 	 * Tune reconstruction:
6016 	 */
6017 	window = 32*(PAGE_SIZE/512);
6018 	printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
6019 		window/2,(unsigned long long) max_sectors/2);
6020 
6021 	atomic_set(&mddev->recovery_active, 0);
6022 	last_check = 0;
6023 
6024 	if (j>2) {
6025 		printk(KERN_INFO
6026 		       "md: resuming %s of %s from checkpoint.\n",
6027 		       desc, mdname(mddev));
6028 		mddev->curr_resync = j;
6029 	}
6030 
6031 	while (j < max_sectors) {
6032 		sector_t sectors;
6033 
6034 		skipped = 0;
6035 		if (j >= mddev->resync_max) {
6036 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6037 			wait_event(mddev->recovery_wait,
6038 				   mddev->resync_max > j
6039 				   || kthread_should_stop());
6040 		}
6041 		if (kthread_should_stop())
6042 			goto interrupted;
6043 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
6044 						  currspeed < speed_min(mddev));
6045 		if (sectors == 0) {
6046 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6047 			goto out;
6048 		}
6049 
6050 		if (!skipped) { /* actual IO requested */
6051 			io_sectors += sectors;
6052 			atomic_add(sectors, &mddev->recovery_active);
6053 		}
6054 
6055 		j += sectors;
6056 		if (j>1) mddev->curr_resync = j;
6057 		mddev->curr_mark_cnt = io_sectors;
6058 		if (last_check == 0)
6059 			/* this is the earliers that rebuilt will be
6060 			 * visible in /proc/mdstat
6061 			 */
6062 			md_new_event(mddev);
6063 
6064 		if (last_check + window > io_sectors || j == max_sectors)
6065 			continue;
6066 
6067 		last_check = io_sectors;
6068 
6069 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6070 			break;
6071 
6072 	repeat:
6073 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
6074 			/* step marks */
6075 			int next = (last_mark+1) % SYNC_MARKS;
6076 
6077 			mddev->resync_mark = mark[next];
6078 			mddev->resync_mark_cnt = mark_cnt[next];
6079 			mark[next] = jiffies;
6080 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
6081 			last_mark = next;
6082 		}
6083 
6084 
6085 		if (kthread_should_stop())
6086 			goto interrupted;
6087 
6088 
6089 		/*
6090 		 * this loop exits only if either when we are slower than
6091 		 * the 'hard' speed limit, or the system was IO-idle for
6092 		 * a jiffy.
6093 		 * the system might be non-idle CPU-wise, but we only care
6094 		 * about not overloading the IO subsystem. (things like an
6095 		 * e2fsck being done on the RAID array should execute fast)
6096 		 */
6097 		blk_unplug(mddev->queue);
6098 		cond_resched();
6099 
6100 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
6101 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
6102 
6103 		if (currspeed > speed_min(mddev)) {
6104 			if ((currspeed > speed_max(mddev)) ||
6105 					!is_mddev_idle(mddev)) {
6106 				msleep(500);
6107 				goto repeat;
6108 			}
6109 		}
6110 	}
6111 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
6112 	/*
6113 	 * this also signals 'finished resyncing' to md_stop
6114 	 */
6115  out:
6116 	blk_unplug(mddev->queue);
6117 
6118 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
6119 
6120 	/* tell personality that we are finished */
6121 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
6122 
6123 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
6124 	    mddev->curr_resync > 2) {
6125 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6126 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6127 				if (mddev->curr_resync >= mddev->recovery_cp) {
6128 					printk(KERN_INFO
6129 					       "md: checkpointing %s of %s.\n",
6130 					       desc, mdname(mddev));
6131 					mddev->recovery_cp = mddev->curr_resync;
6132 				}
6133 			} else
6134 				mddev->recovery_cp = MaxSector;
6135 		} else {
6136 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
6137 				mddev->curr_resync = MaxSector;
6138 			list_for_each_entry(rdev, &mddev->disks, same_set)
6139 				if (rdev->raid_disk >= 0 &&
6140 				    !test_bit(Faulty, &rdev->flags) &&
6141 				    !test_bit(In_sync, &rdev->flags) &&
6142 				    rdev->recovery_offset < mddev->curr_resync)
6143 					rdev->recovery_offset = mddev->curr_resync;
6144 		}
6145 	}
6146 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
6147 
6148  skip:
6149 	mddev->curr_resync = 0;
6150 	mddev->resync_min = 0;
6151 	mddev->resync_max = MaxSector;
6152 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
6153 	wake_up(&resync_wait);
6154 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
6155 	md_wakeup_thread(mddev->thread);
6156 	return;
6157 
6158  interrupted:
6159 	/*
6160 	 * got a signal, exit.
6161 	 */
6162 	printk(KERN_INFO
6163 	       "md: md_do_sync() got signal ... exiting\n");
6164 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6165 	goto out;
6166 
6167 }
6168 EXPORT_SYMBOL_GPL(md_do_sync);
6169 
6170 
6171 static int remove_and_add_spares(mddev_t *mddev)
6172 {
6173 	mdk_rdev_t *rdev;
6174 	int spares = 0;
6175 
6176 	list_for_each_entry(rdev, &mddev->disks, same_set)
6177 		if (rdev->raid_disk >= 0 &&
6178 		    !test_bit(Blocked, &rdev->flags) &&
6179 		    (test_bit(Faulty, &rdev->flags) ||
6180 		     ! test_bit(In_sync, &rdev->flags)) &&
6181 		    atomic_read(&rdev->nr_pending)==0) {
6182 			if (mddev->pers->hot_remove_disk(
6183 				    mddev, rdev->raid_disk)==0) {
6184 				char nm[20];
6185 				sprintf(nm,"rd%d", rdev->raid_disk);
6186 				sysfs_remove_link(&mddev->kobj, nm);
6187 				rdev->raid_disk = -1;
6188 			}
6189 		}
6190 
6191 	if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
6192 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6193 			if (rdev->raid_disk >= 0 &&
6194 			    !test_bit(In_sync, &rdev->flags) &&
6195 			    !test_bit(Blocked, &rdev->flags))
6196 				spares++;
6197 			if (rdev->raid_disk < 0
6198 			    && !test_bit(Faulty, &rdev->flags)) {
6199 				rdev->recovery_offset = 0;
6200 				if (mddev->pers->
6201 				    hot_add_disk(mddev, rdev) == 0) {
6202 					char nm[20];
6203 					sprintf(nm, "rd%d", rdev->raid_disk);
6204 					if (sysfs_create_link(&mddev->kobj,
6205 							      &rdev->kobj, nm))
6206 						printk(KERN_WARNING
6207 						       "md: cannot register "
6208 						       "%s for %s\n",
6209 						       nm, mdname(mddev));
6210 					spares++;
6211 					md_new_event(mddev);
6212 				} else
6213 					break;
6214 			}
6215 		}
6216 	}
6217 	return spares;
6218 }
6219 /*
6220  * This routine is regularly called by all per-raid-array threads to
6221  * deal with generic issues like resync and super-block update.
6222  * Raid personalities that don't have a thread (linear/raid0) do not
6223  * need this as they never do any recovery or update the superblock.
6224  *
6225  * It does not do any resync itself, but rather "forks" off other threads
6226  * to do that as needed.
6227  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
6228  * "->recovery" and create a thread at ->sync_thread.
6229  * When the thread finishes it sets MD_RECOVERY_DONE
6230  * and wakeups up this thread which will reap the thread and finish up.
6231  * This thread also removes any faulty devices (with nr_pending == 0).
6232  *
6233  * The overall approach is:
6234  *  1/ if the superblock needs updating, update it.
6235  *  2/ If a recovery thread is running, don't do anything else.
6236  *  3/ If recovery has finished, clean up, possibly marking spares active.
6237  *  4/ If there are any faulty devices, remove them.
6238  *  5/ If array is degraded, try to add spares devices
6239  *  6/ If array has spares or is not in-sync, start a resync thread.
6240  */
6241 void md_check_recovery(mddev_t *mddev)
6242 {
6243 	mdk_rdev_t *rdev;
6244 
6245 
6246 	if (mddev->bitmap)
6247 		bitmap_daemon_work(mddev->bitmap);
6248 
6249 	if (mddev->ro)
6250 		return;
6251 
6252 	if (signal_pending(current)) {
6253 		if (mddev->pers->sync_request && !mddev->external) {
6254 			printk(KERN_INFO "md: %s in immediate safe mode\n",
6255 			       mdname(mddev));
6256 			mddev->safemode = 2;
6257 		}
6258 		flush_signals(current);
6259 	}
6260 
6261 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
6262 		return;
6263 	if ( ! (
6264 		(mddev->flags && !mddev->external) ||
6265 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
6266 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
6267 		(mddev->external == 0 && mddev->safemode == 1) ||
6268 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
6269 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
6270 		))
6271 		return;
6272 
6273 	if (mddev_trylock(mddev)) {
6274 		int spares = 0;
6275 
6276 		if (mddev->ro) {
6277 			/* Only thing we do on a ro array is remove
6278 			 * failed devices.
6279 			 */
6280 			remove_and_add_spares(mddev);
6281 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6282 			goto unlock;
6283 		}
6284 
6285 		if (!mddev->external) {
6286 			int did_change = 0;
6287 			spin_lock_irq(&mddev->write_lock);
6288 			if (mddev->safemode &&
6289 			    !atomic_read(&mddev->writes_pending) &&
6290 			    !mddev->in_sync &&
6291 			    mddev->recovery_cp == MaxSector) {
6292 				mddev->in_sync = 1;
6293 				did_change = 1;
6294 				if (mddev->persistent)
6295 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6296 			}
6297 			if (mddev->safemode == 1)
6298 				mddev->safemode = 0;
6299 			spin_unlock_irq(&mddev->write_lock);
6300 			if (did_change)
6301 				sysfs_notify_dirent(mddev->sysfs_state);
6302 		}
6303 
6304 		if (mddev->flags)
6305 			md_update_sb(mddev, 0);
6306 
6307 		list_for_each_entry(rdev, &mddev->disks, same_set)
6308 			if (test_and_clear_bit(StateChanged, &rdev->flags))
6309 				sysfs_notify_dirent(rdev->sysfs_state);
6310 
6311 
6312 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
6313 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
6314 			/* resync/recovery still happening */
6315 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6316 			goto unlock;
6317 		}
6318 		if (mddev->sync_thread) {
6319 			/* resync has finished, collect result */
6320 			md_unregister_thread(mddev->sync_thread);
6321 			mddev->sync_thread = NULL;
6322 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
6323 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
6324 				/* success...*/
6325 				/* activate any spares */
6326 				if (mddev->pers->spare_active(mddev))
6327 					sysfs_notify(&mddev->kobj, NULL,
6328 						     "degraded");
6329 			}
6330 			md_update_sb(mddev, 1);
6331 
6332 			/* if array is no-longer degraded, then any saved_raid_disk
6333 			 * information must be scrapped
6334 			 */
6335 			if (!mddev->degraded)
6336 				list_for_each_entry(rdev, &mddev->disks, same_set)
6337 					rdev->saved_raid_disk = -1;
6338 
6339 			mddev->recovery = 0;
6340 			/* flag recovery needed just to double check */
6341 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6342 			sysfs_notify_dirent(mddev->sysfs_action);
6343 			md_new_event(mddev);
6344 			goto unlock;
6345 		}
6346 		/* Set RUNNING before clearing NEEDED to avoid
6347 		 * any transients in the value of "sync_action".
6348 		 */
6349 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6350 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6351 		/* Clear some bits that don't mean anything, but
6352 		 * might be left set
6353 		 */
6354 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
6355 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
6356 
6357 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
6358 			goto unlock;
6359 		/* no recovery is running.
6360 		 * remove any failed drives, then
6361 		 * add spares if possible.
6362 		 * Spare are also removed and re-added, to allow
6363 		 * the personality to fail the re-add.
6364 		 */
6365 
6366 		if (mddev->reshape_position != MaxSector) {
6367 			if (mddev->pers->check_reshape(mddev) != 0)
6368 				/* Cannot proceed */
6369 				goto unlock;
6370 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6371 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6372 		} else if ((spares = remove_and_add_spares(mddev))) {
6373 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6374 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6375 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
6376 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6377 		} else if (mddev->recovery_cp < MaxSector) {
6378 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6379 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6380 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6381 			/* nothing to be done ... */
6382 			goto unlock;
6383 
6384 		if (mddev->pers->sync_request) {
6385 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
6386 				/* We are adding a device or devices to an array
6387 				 * which has the bitmap stored on all devices.
6388 				 * So make sure all bitmap pages get written
6389 				 */
6390 				bitmap_write_all(mddev->bitmap);
6391 			}
6392 			mddev->sync_thread = md_register_thread(md_do_sync,
6393 								mddev,
6394 								"%s_resync");
6395 			if (!mddev->sync_thread) {
6396 				printk(KERN_ERR "%s: could not start resync"
6397 					" thread...\n",
6398 					mdname(mddev));
6399 				/* leave the spares where they are, it shouldn't hurt */
6400 				mddev->recovery = 0;
6401 			} else
6402 				md_wakeup_thread(mddev->sync_thread);
6403 			sysfs_notify_dirent(mddev->sysfs_action);
6404 			md_new_event(mddev);
6405 		}
6406 	unlock:
6407 		if (!mddev->sync_thread) {
6408 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6409 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
6410 					       &mddev->recovery))
6411 				if (mddev->sysfs_action)
6412 					sysfs_notify_dirent(mddev->sysfs_action);
6413 		}
6414 		mddev_unlock(mddev);
6415 	}
6416 }
6417 
6418 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
6419 {
6420 	sysfs_notify_dirent(rdev->sysfs_state);
6421 	wait_event_timeout(rdev->blocked_wait,
6422 			   !test_bit(Blocked, &rdev->flags),
6423 			   msecs_to_jiffies(5000));
6424 	rdev_dec_pending(rdev, mddev);
6425 }
6426 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
6427 
6428 static int md_notify_reboot(struct notifier_block *this,
6429 			    unsigned long code, void *x)
6430 {
6431 	struct list_head *tmp;
6432 	mddev_t *mddev;
6433 
6434 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
6435 
6436 		printk(KERN_INFO "md: stopping all md devices.\n");
6437 
6438 		for_each_mddev(mddev, tmp)
6439 			if (mddev_trylock(mddev)) {
6440 				/* Force a switch to readonly even array
6441 				 * appears to still be in use.  Hence
6442 				 * the '100'.
6443 				 */
6444 				do_md_stop(mddev, 1, 100);
6445 				mddev_unlock(mddev);
6446 			}
6447 		/*
6448 		 * certain more exotic SCSI devices are known to be
6449 		 * volatile wrt too early system reboots. While the
6450 		 * right place to handle this issue is the given
6451 		 * driver, we do want to have a safe RAID driver ...
6452 		 */
6453 		mdelay(1000*1);
6454 	}
6455 	return NOTIFY_DONE;
6456 }
6457 
6458 static struct notifier_block md_notifier = {
6459 	.notifier_call	= md_notify_reboot,
6460 	.next		= NULL,
6461 	.priority	= INT_MAX, /* before any real devices */
6462 };
6463 
6464 static void md_geninit(void)
6465 {
6466 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
6467 
6468 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
6469 }
6470 
6471 static int __init md_init(void)
6472 {
6473 	if (register_blkdev(MAJOR_NR, "md"))
6474 		return -1;
6475 	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
6476 		unregister_blkdev(MAJOR_NR, "md");
6477 		return -1;
6478 	}
6479 	blk_register_region(MKDEV(MAJOR_NR, 0), 1UL<<MINORBITS, THIS_MODULE,
6480 			    md_probe, NULL, NULL);
6481 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
6482 			    md_probe, NULL, NULL);
6483 
6484 	register_reboot_notifier(&md_notifier);
6485 	raid_table_header = register_sysctl_table(raid_root_table);
6486 
6487 	md_geninit();
6488 	return 0;
6489 }
6490 
6491 
6492 #ifndef MODULE
6493 
6494 /*
6495  * Searches all registered partitions for autorun RAID arrays
6496  * at boot time.
6497  */
6498 
6499 static LIST_HEAD(all_detected_devices);
6500 struct detected_devices_node {
6501 	struct list_head list;
6502 	dev_t dev;
6503 };
6504 
6505 void md_autodetect_dev(dev_t dev)
6506 {
6507 	struct detected_devices_node *node_detected_dev;
6508 
6509 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
6510 	if (node_detected_dev) {
6511 		node_detected_dev->dev = dev;
6512 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
6513 	} else {
6514 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
6515 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
6516 	}
6517 }
6518 
6519 
6520 static void autostart_arrays(int part)
6521 {
6522 	mdk_rdev_t *rdev;
6523 	struct detected_devices_node *node_detected_dev;
6524 	dev_t dev;
6525 	int i_scanned, i_passed;
6526 
6527 	i_scanned = 0;
6528 	i_passed = 0;
6529 
6530 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
6531 
6532 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
6533 		i_scanned++;
6534 		node_detected_dev = list_entry(all_detected_devices.next,
6535 					struct detected_devices_node, list);
6536 		list_del(&node_detected_dev->list);
6537 		dev = node_detected_dev->dev;
6538 		kfree(node_detected_dev);
6539 		rdev = md_import_device(dev,0, 90);
6540 		if (IS_ERR(rdev))
6541 			continue;
6542 
6543 		if (test_bit(Faulty, &rdev->flags)) {
6544 			MD_BUG();
6545 			continue;
6546 		}
6547 		set_bit(AutoDetected, &rdev->flags);
6548 		list_add(&rdev->same_set, &pending_raid_disks);
6549 		i_passed++;
6550 	}
6551 
6552 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
6553 						i_scanned, i_passed);
6554 
6555 	autorun_devices(part);
6556 }
6557 
6558 #endif /* !MODULE */
6559 
6560 static __exit void md_exit(void)
6561 {
6562 	mddev_t *mddev;
6563 	struct list_head *tmp;
6564 
6565 	blk_unregister_region(MKDEV(MAJOR_NR,0), 1U << MINORBITS);
6566 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
6567 
6568 	unregister_blkdev(MAJOR_NR,"md");
6569 	unregister_blkdev(mdp_major, "mdp");
6570 	unregister_reboot_notifier(&md_notifier);
6571 	unregister_sysctl_table(raid_table_header);
6572 	remove_proc_entry("mdstat", NULL);
6573 	for_each_mddev(mddev, tmp) {
6574 		export_array(mddev);
6575 		mddev->hold_active = 0;
6576 	}
6577 }
6578 
6579 subsys_initcall(md_init);
6580 module_exit(md_exit)
6581 
6582 static int get_ro(char *buffer, struct kernel_param *kp)
6583 {
6584 	return sprintf(buffer, "%d", start_readonly);
6585 }
6586 static int set_ro(const char *val, struct kernel_param *kp)
6587 {
6588 	char *e;
6589 	int num = simple_strtoul(val, &e, 10);
6590 	if (*val && (*e == '\0' || *e == '\n')) {
6591 		start_readonly = num;
6592 		return 0;
6593 	}
6594 	return -EINVAL;
6595 }
6596 
6597 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
6598 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
6599 
6600 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
6601 
6602 EXPORT_SYMBOL(register_md_personality);
6603 EXPORT_SYMBOL(unregister_md_personality);
6604 EXPORT_SYMBOL(md_error);
6605 EXPORT_SYMBOL(md_done_sync);
6606 EXPORT_SYMBOL(md_write_start);
6607 EXPORT_SYMBOL(md_write_end);
6608 EXPORT_SYMBOL(md_register_thread);
6609 EXPORT_SYMBOL(md_unregister_thread);
6610 EXPORT_SYMBOL(md_wakeup_thread);
6611 EXPORT_SYMBOL(md_check_recovery);
6612 MODULE_LICENSE("GPL");
6613 MODULE_ALIAS("md");
6614 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
6615