xref: /linux/drivers/md/md.c (revision 7c43185138cf523b0810ffd2c9e18e2ecb356730)
1 /*
2    md.c : Multiple Devices driver for Linux
3 	  Copyright (C) 1998, 1999, 2000 Ingo Molnar
4 
5      completely rewritten, based on the MD driver code from Marc Zyngier
6 
7    Changes:
8 
9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
13    - kmod support by: Cyrus Durgin
14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
16 
17    - lots of fixes and improvements to the RAID1/RAID5 and generic
18      RAID code (such as request based resynchronization):
19 
20      Neil Brown <neilb@cse.unsw.edu.au>.
21 
22    - persistent bitmap code
23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
24 
25    This program is free software; you can redistribute it and/or modify
26    it under the terms of the GNU General Public License as published by
27    the Free Software Foundation; either version 2, or (at your option)
28    any later version.
29 
30    You should have received a copy of the GNU General Public License
31    (for example /usr/src/linux/COPYING); if not, write to the Free
32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 */
34 
35 #include <linux/kthread.h>
36 #include <linux/blkdev.h>
37 #include <linux/sysctl.h>
38 #include <linux/seq_file.h>
39 #include <linux/mutex.h>
40 #include <linux/buffer_head.h> /* for invalidate_bdev */
41 #include <linux/poll.h>
42 #include <linux/ctype.h>
43 #include <linux/string.h>
44 #include <linux/hdreg.h>
45 #include <linux/proc_fs.h>
46 #include <linux/random.h>
47 #include <linux/reboot.h>
48 #include <linux/file.h>
49 #include <linux/compat.h>
50 #include <linux/delay.h>
51 #include <linux/raid/md_p.h>
52 #include <linux/raid/md_u.h>
53 #include <linux/slab.h>
54 #include "md.h"
55 #include "bitmap.h"
56 
57 #define DEBUG 0
58 #define dprintk(x...) ((void)(DEBUG && printk(x)))
59 
60 #ifndef MODULE
61 static void autostart_arrays(int part);
62 #endif
63 
64 static LIST_HEAD(pers_list);
65 static DEFINE_SPINLOCK(pers_lock);
66 
67 static void md_print_devices(void);
68 
69 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
70 static struct workqueue_struct *md_wq;
71 static struct workqueue_struct *md_misc_wq;
72 
73 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
74 
75 /*
76  * Default number of read corrections we'll attempt on an rdev
77  * before ejecting it from the array. We divide the read error
78  * count by 2 for every hour elapsed between read errors.
79  */
80 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
81 /*
82  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
83  * is 1000 KB/sec, so the extra system load does not show up that much.
84  * Increase it if you want to have more _guaranteed_ speed. Note that
85  * the RAID driver will use the maximum available bandwidth if the IO
86  * subsystem is idle. There is also an 'absolute maximum' reconstruction
87  * speed limit - in case reconstruction slows down your system despite
88  * idle IO detection.
89  *
90  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
91  * or /sys/block/mdX/md/sync_speed_{min,max}
92  */
93 
94 static int sysctl_speed_limit_min = 1000;
95 static int sysctl_speed_limit_max = 200000;
96 static inline int speed_min(mddev_t *mddev)
97 {
98 	return mddev->sync_speed_min ?
99 		mddev->sync_speed_min : sysctl_speed_limit_min;
100 }
101 
102 static inline int speed_max(mddev_t *mddev)
103 {
104 	return mddev->sync_speed_max ?
105 		mddev->sync_speed_max : sysctl_speed_limit_max;
106 }
107 
108 static struct ctl_table_header *raid_table_header;
109 
110 static ctl_table raid_table[] = {
111 	{
112 		.procname	= "speed_limit_min",
113 		.data		= &sysctl_speed_limit_min,
114 		.maxlen		= sizeof(int),
115 		.mode		= S_IRUGO|S_IWUSR,
116 		.proc_handler	= proc_dointvec,
117 	},
118 	{
119 		.procname	= "speed_limit_max",
120 		.data		= &sysctl_speed_limit_max,
121 		.maxlen		= sizeof(int),
122 		.mode		= S_IRUGO|S_IWUSR,
123 		.proc_handler	= proc_dointvec,
124 	},
125 	{ }
126 };
127 
128 static ctl_table raid_dir_table[] = {
129 	{
130 		.procname	= "raid",
131 		.maxlen		= 0,
132 		.mode		= S_IRUGO|S_IXUGO,
133 		.child		= raid_table,
134 	},
135 	{ }
136 };
137 
138 static ctl_table raid_root_table[] = {
139 	{
140 		.procname	= "dev",
141 		.maxlen		= 0,
142 		.mode		= 0555,
143 		.child		= raid_dir_table,
144 	},
145 	{  }
146 };
147 
148 static const struct block_device_operations md_fops;
149 
150 static int start_readonly;
151 
152 /* bio_clone_mddev
153  * like bio_clone, but with a local bio set
154  */
155 
156 static void mddev_bio_destructor(struct bio *bio)
157 {
158 	mddev_t *mddev, **mddevp;
159 
160 	mddevp = (void*)bio;
161 	mddev = mddevp[-1];
162 
163 	bio_free(bio, mddev->bio_set);
164 }
165 
166 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
167 			    mddev_t *mddev)
168 {
169 	struct bio *b;
170 	mddev_t **mddevp;
171 
172 	if (!mddev || !mddev->bio_set)
173 		return bio_alloc(gfp_mask, nr_iovecs);
174 
175 	b = bio_alloc_bioset(gfp_mask, nr_iovecs,
176 			     mddev->bio_set);
177 	if (!b)
178 		return NULL;
179 	mddevp = (void*)b;
180 	mddevp[-1] = mddev;
181 	b->bi_destructor = mddev_bio_destructor;
182 	return b;
183 }
184 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
185 
186 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
187 			    mddev_t *mddev)
188 {
189 	struct bio *b;
190 	mddev_t **mddevp;
191 
192 	if (!mddev || !mddev->bio_set)
193 		return bio_clone(bio, gfp_mask);
194 
195 	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
196 			     mddev->bio_set);
197 	if (!b)
198 		return NULL;
199 	mddevp = (void*)b;
200 	mddevp[-1] = mddev;
201 	b->bi_destructor = mddev_bio_destructor;
202 	__bio_clone(b, bio);
203 	if (bio_integrity(bio)) {
204 		int ret;
205 
206 		ret = bio_integrity_clone(b, bio, gfp_mask, mddev->bio_set);
207 
208 		if (ret < 0) {
209 			bio_put(b);
210 			return NULL;
211 		}
212 	}
213 
214 	return b;
215 }
216 EXPORT_SYMBOL_GPL(bio_clone_mddev);
217 
218 void md_trim_bio(struct bio *bio, int offset, int size)
219 {
220 	/* 'bio' is a cloned bio which we need to trim to match
221 	 * the given offset and size.
222 	 * This requires adjusting bi_sector, bi_size, and bi_io_vec
223 	 */
224 	int i;
225 	struct bio_vec *bvec;
226 	int sofar = 0;
227 
228 	size <<= 9;
229 	if (offset == 0 && size == bio->bi_size)
230 		return;
231 
232 	bio->bi_sector += offset;
233 	bio->bi_size = size;
234 	offset <<= 9;
235 	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
236 
237 	while (bio->bi_idx < bio->bi_vcnt &&
238 	       bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
239 		/* remove this whole bio_vec */
240 		offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
241 		bio->bi_idx++;
242 	}
243 	if (bio->bi_idx < bio->bi_vcnt) {
244 		bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
245 		bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
246 	}
247 	/* avoid any complications with bi_idx being non-zero*/
248 	if (bio->bi_idx) {
249 		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
250 			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
251 		bio->bi_vcnt -= bio->bi_idx;
252 		bio->bi_idx = 0;
253 	}
254 	/* Make sure vcnt and last bv are not too big */
255 	bio_for_each_segment(bvec, bio, i) {
256 		if (sofar + bvec->bv_len > size)
257 			bvec->bv_len = size - sofar;
258 		if (bvec->bv_len == 0) {
259 			bio->bi_vcnt = i;
260 			break;
261 		}
262 		sofar += bvec->bv_len;
263 	}
264 }
265 EXPORT_SYMBOL_GPL(md_trim_bio);
266 
267 /*
268  * We have a system wide 'event count' that is incremented
269  * on any 'interesting' event, and readers of /proc/mdstat
270  * can use 'poll' or 'select' to find out when the event
271  * count increases.
272  *
273  * Events are:
274  *  start array, stop array, error, add device, remove device,
275  *  start build, activate spare
276  */
277 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
278 static atomic_t md_event_count;
279 void md_new_event(mddev_t *mddev)
280 {
281 	atomic_inc(&md_event_count);
282 	wake_up(&md_event_waiters);
283 }
284 EXPORT_SYMBOL_GPL(md_new_event);
285 
286 /* Alternate version that can be called from interrupts
287  * when calling sysfs_notify isn't needed.
288  */
289 static void md_new_event_inintr(mddev_t *mddev)
290 {
291 	atomic_inc(&md_event_count);
292 	wake_up(&md_event_waiters);
293 }
294 
295 /*
296  * Enables to iterate over all existing md arrays
297  * all_mddevs_lock protects this list.
298  */
299 static LIST_HEAD(all_mddevs);
300 static DEFINE_SPINLOCK(all_mddevs_lock);
301 
302 
303 /*
304  * iterates through all used mddevs in the system.
305  * We take care to grab the all_mddevs_lock whenever navigating
306  * the list, and to always hold a refcount when unlocked.
307  * Any code which breaks out of this loop while own
308  * a reference to the current mddev and must mddev_put it.
309  */
310 #define for_each_mddev(mddev,tmp)					\
311 									\
312 	for (({ spin_lock(&all_mddevs_lock); 				\
313 		tmp = all_mddevs.next;					\
314 		mddev = NULL;});					\
315 	     ({ if (tmp != &all_mddevs)					\
316 			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
317 		spin_unlock(&all_mddevs_lock);				\
318 		if (mddev) mddev_put(mddev);				\
319 		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
320 		tmp != &all_mddevs;});					\
321 	     ({ spin_lock(&all_mddevs_lock);				\
322 		tmp = tmp->next;})					\
323 		)
324 
325 
326 /* Rather than calling directly into the personality make_request function,
327  * IO requests come here first so that we can check if the device is
328  * being suspended pending a reconfiguration.
329  * We hold a refcount over the call to ->make_request.  By the time that
330  * call has finished, the bio has been linked into some internal structure
331  * and so is visible to ->quiesce(), so we don't need the refcount any more.
332  */
333 static int md_make_request(struct request_queue *q, struct bio *bio)
334 {
335 	const int rw = bio_data_dir(bio);
336 	mddev_t *mddev = q->queuedata;
337 	int rv;
338 	int cpu;
339 	unsigned int sectors;
340 
341 	if (mddev == NULL || mddev->pers == NULL
342 	    || !mddev->ready) {
343 		bio_io_error(bio);
344 		return 0;
345 	}
346 	smp_rmb(); /* Ensure implications of  'active' are visible */
347 	rcu_read_lock();
348 	if (mddev->suspended) {
349 		DEFINE_WAIT(__wait);
350 		for (;;) {
351 			prepare_to_wait(&mddev->sb_wait, &__wait,
352 					TASK_UNINTERRUPTIBLE);
353 			if (!mddev->suspended)
354 				break;
355 			rcu_read_unlock();
356 			schedule();
357 			rcu_read_lock();
358 		}
359 		finish_wait(&mddev->sb_wait, &__wait);
360 	}
361 	atomic_inc(&mddev->active_io);
362 	rcu_read_unlock();
363 
364 	/*
365 	 * save the sectors now since our bio can
366 	 * go away inside make_request
367 	 */
368 	sectors = bio_sectors(bio);
369 	rv = mddev->pers->make_request(mddev, bio);
370 
371 	cpu = part_stat_lock();
372 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
373 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
374 	part_stat_unlock();
375 
376 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
377 		wake_up(&mddev->sb_wait);
378 
379 	return rv;
380 }
381 
382 /* mddev_suspend makes sure no new requests are submitted
383  * to the device, and that any requests that have been submitted
384  * are completely handled.
385  * Once ->stop is called and completes, the module will be completely
386  * unused.
387  */
388 void mddev_suspend(mddev_t *mddev)
389 {
390 	BUG_ON(mddev->suspended);
391 	mddev->suspended = 1;
392 	synchronize_rcu();
393 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
394 	mddev->pers->quiesce(mddev, 1);
395 }
396 EXPORT_SYMBOL_GPL(mddev_suspend);
397 
398 void mddev_resume(mddev_t *mddev)
399 {
400 	mddev->suspended = 0;
401 	wake_up(&mddev->sb_wait);
402 	mddev->pers->quiesce(mddev, 0);
403 
404 	md_wakeup_thread(mddev->thread);
405 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
406 }
407 EXPORT_SYMBOL_GPL(mddev_resume);
408 
409 int mddev_congested(mddev_t *mddev, int bits)
410 {
411 	return mddev->suspended;
412 }
413 EXPORT_SYMBOL(mddev_congested);
414 
415 /*
416  * Generic flush handling for md
417  */
418 
419 static void md_end_flush(struct bio *bio, int err)
420 {
421 	mdk_rdev_t *rdev = bio->bi_private;
422 	mddev_t *mddev = rdev->mddev;
423 
424 	rdev_dec_pending(rdev, mddev);
425 
426 	if (atomic_dec_and_test(&mddev->flush_pending)) {
427 		/* The pre-request flush has finished */
428 		queue_work(md_wq, &mddev->flush_work);
429 	}
430 	bio_put(bio);
431 }
432 
433 static void md_submit_flush_data(struct work_struct *ws);
434 
435 static void submit_flushes(struct work_struct *ws)
436 {
437 	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
438 	mdk_rdev_t *rdev;
439 
440 	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
441 	atomic_set(&mddev->flush_pending, 1);
442 	rcu_read_lock();
443 	list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
444 		if (rdev->raid_disk >= 0 &&
445 		    !test_bit(Faulty, &rdev->flags)) {
446 			/* Take two references, one is dropped
447 			 * when request finishes, one after
448 			 * we reclaim rcu_read_lock
449 			 */
450 			struct bio *bi;
451 			atomic_inc(&rdev->nr_pending);
452 			atomic_inc(&rdev->nr_pending);
453 			rcu_read_unlock();
454 			bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
455 			bi->bi_end_io = md_end_flush;
456 			bi->bi_private = rdev;
457 			bi->bi_bdev = rdev->bdev;
458 			atomic_inc(&mddev->flush_pending);
459 			submit_bio(WRITE_FLUSH, bi);
460 			rcu_read_lock();
461 			rdev_dec_pending(rdev, mddev);
462 		}
463 	rcu_read_unlock();
464 	if (atomic_dec_and_test(&mddev->flush_pending))
465 		queue_work(md_wq, &mddev->flush_work);
466 }
467 
468 static void md_submit_flush_data(struct work_struct *ws)
469 {
470 	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
471 	struct bio *bio = mddev->flush_bio;
472 
473 	if (bio->bi_size == 0)
474 		/* an empty barrier - all done */
475 		bio_endio(bio, 0);
476 	else {
477 		bio->bi_rw &= ~REQ_FLUSH;
478 		if (mddev->pers->make_request(mddev, bio))
479 			generic_make_request(bio);
480 	}
481 
482 	mddev->flush_bio = NULL;
483 	wake_up(&mddev->sb_wait);
484 }
485 
486 void md_flush_request(mddev_t *mddev, struct bio *bio)
487 {
488 	spin_lock_irq(&mddev->write_lock);
489 	wait_event_lock_irq(mddev->sb_wait,
490 			    !mddev->flush_bio,
491 			    mddev->write_lock, /*nothing*/);
492 	mddev->flush_bio = bio;
493 	spin_unlock_irq(&mddev->write_lock);
494 
495 	INIT_WORK(&mddev->flush_work, submit_flushes);
496 	queue_work(md_wq, &mddev->flush_work);
497 }
498 EXPORT_SYMBOL(md_flush_request);
499 
500 /* Support for plugging.
501  * This mirrors the plugging support in request_queue, but does not
502  * require having a whole queue or request structures.
503  * We allocate an md_plug_cb for each md device and each thread it gets
504  * plugged on.  This links tot the private plug_handle structure in the
505  * personality data where we keep a count of the number of outstanding
506  * plugs so other code can see if a plug is active.
507  */
508 struct md_plug_cb {
509 	struct blk_plug_cb cb;
510 	mddev_t *mddev;
511 };
512 
513 static void plugger_unplug(struct blk_plug_cb *cb)
514 {
515 	struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb);
516 	if (atomic_dec_and_test(&mdcb->mddev->plug_cnt))
517 		md_wakeup_thread(mdcb->mddev->thread);
518 	kfree(mdcb);
519 }
520 
521 /* Check that an unplug wakeup will come shortly.
522  * If not, wakeup the md thread immediately
523  */
524 int mddev_check_plugged(mddev_t *mddev)
525 {
526 	struct blk_plug *plug = current->plug;
527 	struct md_plug_cb *mdcb;
528 
529 	if (!plug)
530 		return 0;
531 
532 	list_for_each_entry(mdcb, &plug->cb_list, cb.list) {
533 		if (mdcb->cb.callback == plugger_unplug &&
534 		    mdcb->mddev == mddev) {
535 			/* Already on the list, move to top */
536 			if (mdcb != list_first_entry(&plug->cb_list,
537 						    struct md_plug_cb,
538 						    cb.list))
539 				list_move(&mdcb->cb.list, &plug->cb_list);
540 			return 1;
541 		}
542 	}
543 	/* Not currently on the callback list */
544 	mdcb = kmalloc(sizeof(*mdcb), GFP_ATOMIC);
545 	if (!mdcb)
546 		return 0;
547 
548 	mdcb->mddev = mddev;
549 	mdcb->cb.callback = plugger_unplug;
550 	atomic_inc(&mddev->plug_cnt);
551 	list_add(&mdcb->cb.list, &plug->cb_list);
552 	return 1;
553 }
554 EXPORT_SYMBOL_GPL(mddev_check_plugged);
555 
556 static inline mddev_t *mddev_get(mddev_t *mddev)
557 {
558 	atomic_inc(&mddev->active);
559 	return mddev;
560 }
561 
562 static void mddev_delayed_delete(struct work_struct *ws);
563 
564 static void mddev_put(mddev_t *mddev)
565 {
566 	struct bio_set *bs = NULL;
567 
568 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
569 		return;
570 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
571 	    mddev->ctime == 0 && !mddev->hold_active) {
572 		/* Array is not configured at all, and not held active,
573 		 * so destroy it */
574 		list_del(&mddev->all_mddevs);
575 		bs = mddev->bio_set;
576 		mddev->bio_set = NULL;
577 		if (mddev->gendisk) {
578 			/* We did a probe so need to clean up.  Call
579 			 * queue_work inside the spinlock so that
580 			 * flush_workqueue() after mddev_find will
581 			 * succeed in waiting for the work to be done.
582 			 */
583 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
584 			queue_work(md_misc_wq, &mddev->del_work);
585 		} else
586 			kfree(mddev);
587 	}
588 	spin_unlock(&all_mddevs_lock);
589 	if (bs)
590 		bioset_free(bs);
591 }
592 
593 void mddev_init(mddev_t *mddev)
594 {
595 	mutex_init(&mddev->open_mutex);
596 	mutex_init(&mddev->reconfig_mutex);
597 	mutex_init(&mddev->bitmap_info.mutex);
598 	INIT_LIST_HEAD(&mddev->disks);
599 	INIT_LIST_HEAD(&mddev->all_mddevs);
600 	init_timer(&mddev->safemode_timer);
601 	atomic_set(&mddev->active, 1);
602 	atomic_set(&mddev->openers, 0);
603 	atomic_set(&mddev->active_io, 0);
604 	atomic_set(&mddev->plug_cnt, 0);
605 	spin_lock_init(&mddev->write_lock);
606 	atomic_set(&mddev->flush_pending, 0);
607 	init_waitqueue_head(&mddev->sb_wait);
608 	init_waitqueue_head(&mddev->recovery_wait);
609 	mddev->reshape_position = MaxSector;
610 	mddev->resync_min = 0;
611 	mddev->resync_max = MaxSector;
612 	mddev->level = LEVEL_NONE;
613 }
614 EXPORT_SYMBOL_GPL(mddev_init);
615 
616 static mddev_t * mddev_find(dev_t unit)
617 {
618 	mddev_t *mddev, *new = NULL;
619 
620 	if (unit && MAJOR(unit) != MD_MAJOR)
621 		unit &= ~((1<<MdpMinorShift)-1);
622 
623  retry:
624 	spin_lock(&all_mddevs_lock);
625 
626 	if (unit) {
627 		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
628 			if (mddev->unit == unit) {
629 				mddev_get(mddev);
630 				spin_unlock(&all_mddevs_lock);
631 				kfree(new);
632 				return mddev;
633 			}
634 
635 		if (new) {
636 			list_add(&new->all_mddevs, &all_mddevs);
637 			spin_unlock(&all_mddevs_lock);
638 			new->hold_active = UNTIL_IOCTL;
639 			return new;
640 		}
641 	} else if (new) {
642 		/* find an unused unit number */
643 		static int next_minor = 512;
644 		int start = next_minor;
645 		int is_free = 0;
646 		int dev = 0;
647 		while (!is_free) {
648 			dev = MKDEV(MD_MAJOR, next_minor);
649 			next_minor++;
650 			if (next_minor > MINORMASK)
651 				next_minor = 0;
652 			if (next_minor == start) {
653 				/* Oh dear, all in use. */
654 				spin_unlock(&all_mddevs_lock);
655 				kfree(new);
656 				return NULL;
657 			}
658 
659 			is_free = 1;
660 			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
661 				if (mddev->unit == dev) {
662 					is_free = 0;
663 					break;
664 				}
665 		}
666 		new->unit = dev;
667 		new->md_minor = MINOR(dev);
668 		new->hold_active = UNTIL_STOP;
669 		list_add(&new->all_mddevs, &all_mddevs);
670 		spin_unlock(&all_mddevs_lock);
671 		return new;
672 	}
673 	spin_unlock(&all_mddevs_lock);
674 
675 	new = kzalloc(sizeof(*new), GFP_KERNEL);
676 	if (!new)
677 		return NULL;
678 
679 	new->unit = unit;
680 	if (MAJOR(unit) == MD_MAJOR)
681 		new->md_minor = MINOR(unit);
682 	else
683 		new->md_minor = MINOR(unit) >> MdpMinorShift;
684 
685 	mddev_init(new);
686 
687 	goto retry;
688 }
689 
690 static inline int mddev_lock(mddev_t * mddev)
691 {
692 	return mutex_lock_interruptible(&mddev->reconfig_mutex);
693 }
694 
695 static inline int mddev_is_locked(mddev_t *mddev)
696 {
697 	return mutex_is_locked(&mddev->reconfig_mutex);
698 }
699 
700 static inline int mddev_trylock(mddev_t * mddev)
701 {
702 	return mutex_trylock(&mddev->reconfig_mutex);
703 }
704 
705 static struct attribute_group md_redundancy_group;
706 
707 static void mddev_unlock(mddev_t * mddev)
708 {
709 	if (mddev->to_remove) {
710 		/* These cannot be removed under reconfig_mutex as
711 		 * an access to the files will try to take reconfig_mutex
712 		 * while holding the file unremovable, which leads to
713 		 * a deadlock.
714 		 * So hold set sysfs_active while the remove in happeing,
715 		 * and anything else which might set ->to_remove or my
716 		 * otherwise change the sysfs namespace will fail with
717 		 * -EBUSY if sysfs_active is still set.
718 		 * We set sysfs_active under reconfig_mutex and elsewhere
719 		 * test it under the same mutex to ensure its correct value
720 		 * is seen.
721 		 */
722 		struct attribute_group *to_remove = mddev->to_remove;
723 		mddev->to_remove = NULL;
724 		mddev->sysfs_active = 1;
725 		mutex_unlock(&mddev->reconfig_mutex);
726 
727 		if (mddev->kobj.sd) {
728 			if (to_remove != &md_redundancy_group)
729 				sysfs_remove_group(&mddev->kobj, to_remove);
730 			if (mddev->pers == NULL ||
731 			    mddev->pers->sync_request == NULL) {
732 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
733 				if (mddev->sysfs_action)
734 					sysfs_put(mddev->sysfs_action);
735 				mddev->sysfs_action = NULL;
736 			}
737 		}
738 		mddev->sysfs_active = 0;
739 	} else
740 		mutex_unlock(&mddev->reconfig_mutex);
741 
742 	md_wakeup_thread(mddev->thread);
743 }
744 
745 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
746 {
747 	mdk_rdev_t *rdev;
748 
749 	list_for_each_entry(rdev, &mddev->disks, same_set)
750 		if (rdev->desc_nr == nr)
751 			return rdev;
752 
753 	return NULL;
754 }
755 
756 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
757 {
758 	mdk_rdev_t *rdev;
759 
760 	list_for_each_entry(rdev, &mddev->disks, same_set)
761 		if (rdev->bdev->bd_dev == dev)
762 			return rdev;
763 
764 	return NULL;
765 }
766 
767 static struct mdk_personality *find_pers(int level, char *clevel)
768 {
769 	struct mdk_personality *pers;
770 	list_for_each_entry(pers, &pers_list, list) {
771 		if (level != LEVEL_NONE && pers->level == level)
772 			return pers;
773 		if (strcmp(pers->name, clevel)==0)
774 			return pers;
775 	}
776 	return NULL;
777 }
778 
779 /* return the offset of the super block in 512byte sectors */
780 static inline sector_t calc_dev_sboffset(mdk_rdev_t *rdev)
781 {
782 	sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
783 	return MD_NEW_SIZE_SECTORS(num_sectors);
784 }
785 
786 static int alloc_disk_sb(mdk_rdev_t * rdev)
787 {
788 	if (rdev->sb_page)
789 		MD_BUG();
790 
791 	rdev->sb_page = alloc_page(GFP_KERNEL);
792 	if (!rdev->sb_page) {
793 		printk(KERN_ALERT "md: out of memory.\n");
794 		return -ENOMEM;
795 	}
796 
797 	return 0;
798 }
799 
800 static void free_disk_sb(mdk_rdev_t * rdev)
801 {
802 	if (rdev->sb_page) {
803 		put_page(rdev->sb_page);
804 		rdev->sb_loaded = 0;
805 		rdev->sb_page = NULL;
806 		rdev->sb_start = 0;
807 		rdev->sectors = 0;
808 	}
809 	if (rdev->bb_page) {
810 		put_page(rdev->bb_page);
811 		rdev->bb_page = NULL;
812 	}
813 }
814 
815 
816 static void super_written(struct bio *bio, int error)
817 {
818 	mdk_rdev_t *rdev = bio->bi_private;
819 	mddev_t *mddev = rdev->mddev;
820 
821 	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
822 		printk("md: super_written gets error=%d, uptodate=%d\n",
823 		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
824 		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
825 		md_error(mddev, rdev);
826 	}
827 
828 	if (atomic_dec_and_test(&mddev->pending_writes))
829 		wake_up(&mddev->sb_wait);
830 	bio_put(bio);
831 }
832 
833 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
834 		   sector_t sector, int size, struct page *page)
835 {
836 	/* write first size bytes of page to sector of rdev
837 	 * Increment mddev->pending_writes before returning
838 	 * and decrement it on completion, waking up sb_wait
839 	 * if zero is reached.
840 	 * If an error occurred, call md_error
841 	 */
842 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
843 
844 	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
845 	bio->bi_sector = sector;
846 	bio_add_page(bio, page, size, 0);
847 	bio->bi_private = rdev;
848 	bio->bi_end_io = super_written;
849 
850 	atomic_inc(&mddev->pending_writes);
851 	submit_bio(REQ_WRITE | REQ_SYNC | REQ_FLUSH | REQ_FUA, bio);
852 }
853 
854 void md_super_wait(mddev_t *mddev)
855 {
856 	/* wait for all superblock writes that were scheduled to complete */
857 	DEFINE_WAIT(wq);
858 	for(;;) {
859 		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
860 		if (atomic_read(&mddev->pending_writes)==0)
861 			break;
862 		schedule();
863 	}
864 	finish_wait(&mddev->sb_wait, &wq);
865 }
866 
867 static void bi_complete(struct bio *bio, int error)
868 {
869 	complete((struct completion*)bio->bi_private);
870 }
871 
872 int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
873 		 struct page *page, int rw, bool metadata_op)
874 {
875 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
876 	struct completion event;
877 	int ret;
878 
879 	rw |= REQ_SYNC;
880 
881 	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
882 		rdev->meta_bdev : rdev->bdev;
883 	if (metadata_op)
884 		bio->bi_sector = sector + rdev->sb_start;
885 	else
886 		bio->bi_sector = sector + rdev->data_offset;
887 	bio_add_page(bio, page, size, 0);
888 	init_completion(&event);
889 	bio->bi_private = &event;
890 	bio->bi_end_io = bi_complete;
891 	submit_bio(rw, bio);
892 	wait_for_completion(&event);
893 
894 	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
895 	bio_put(bio);
896 	return ret;
897 }
898 EXPORT_SYMBOL_GPL(sync_page_io);
899 
900 static int read_disk_sb(mdk_rdev_t * rdev, int size)
901 {
902 	char b[BDEVNAME_SIZE];
903 	if (!rdev->sb_page) {
904 		MD_BUG();
905 		return -EINVAL;
906 	}
907 	if (rdev->sb_loaded)
908 		return 0;
909 
910 
911 	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
912 		goto fail;
913 	rdev->sb_loaded = 1;
914 	return 0;
915 
916 fail:
917 	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
918 		bdevname(rdev->bdev,b));
919 	return -EINVAL;
920 }
921 
922 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
923 {
924 	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
925 		sb1->set_uuid1 == sb2->set_uuid1 &&
926 		sb1->set_uuid2 == sb2->set_uuid2 &&
927 		sb1->set_uuid3 == sb2->set_uuid3;
928 }
929 
930 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
931 {
932 	int ret;
933 	mdp_super_t *tmp1, *tmp2;
934 
935 	tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
936 	tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
937 
938 	if (!tmp1 || !tmp2) {
939 		ret = 0;
940 		printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
941 		goto abort;
942 	}
943 
944 	*tmp1 = *sb1;
945 	*tmp2 = *sb2;
946 
947 	/*
948 	 * nr_disks is not constant
949 	 */
950 	tmp1->nr_disks = 0;
951 	tmp2->nr_disks = 0;
952 
953 	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
954 abort:
955 	kfree(tmp1);
956 	kfree(tmp2);
957 	return ret;
958 }
959 
960 
961 static u32 md_csum_fold(u32 csum)
962 {
963 	csum = (csum & 0xffff) + (csum >> 16);
964 	return (csum & 0xffff) + (csum >> 16);
965 }
966 
967 static unsigned int calc_sb_csum(mdp_super_t * sb)
968 {
969 	u64 newcsum = 0;
970 	u32 *sb32 = (u32*)sb;
971 	int i;
972 	unsigned int disk_csum, csum;
973 
974 	disk_csum = sb->sb_csum;
975 	sb->sb_csum = 0;
976 
977 	for (i = 0; i < MD_SB_BYTES/4 ; i++)
978 		newcsum += sb32[i];
979 	csum = (newcsum & 0xffffffff) + (newcsum>>32);
980 
981 
982 #ifdef CONFIG_ALPHA
983 	/* This used to use csum_partial, which was wrong for several
984 	 * reasons including that different results are returned on
985 	 * different architectures.  It isn't critical that we get exactly
986 	 * the same return value as before (we always csum_fold before
987 	 * testing, and that removes any differences).  However as we
988 	 * know that csum_partial always returned a 16bit value on
989 	 * alphas, do a fold to maximise conformity to previous behaviour.
990 	 */
991 	sb->sb_csum = md_csum_fold(disk_csum);
992 #else
993 	sb->sb_csum = disk_csum;
994 #endif
995 	return csum;
996 }
997 
998 
999 /*
1000  * Handle superblock details.
1001  * We want to be able to handle multiple superblock formats
1002  * so we have a common interface to them all, and an array of
1003  * different handlers.
1004  * We rely on user-space to write the initial superblock, and support
1005  * reading and updating of superblocks.
1006  * Interface methods are:
1007  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
1008  *      loads and validates a superblock on dev.
1009  *      if refdev != NULL, compare superblocks on both devices
1010  *    Return:
1011  *      0 - dev has a superblock that is compatible with refdev
1012  *      1 - dev has a superblock that is compatible and newer than refdev
1013  *          so dev should be used as the refdev in future
1014  *     -EINVAL superblock incompatible or invalid
1015  *     -othererror e.g. -EIO
1016  *
1017  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
1018  *      Verify that dev is acceptable into mddev.
1019  *       The first time, mddev->raid_disks will be 0, and data from
1020  *       dev should be merged in.  Subsequent calls check that dev
1021  *       is new enough.  Return 0 or -EINVAL
1022  *
1023  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
1024  *     Update the superblock for rdev with data in mddev
1025  *     This does not write to disc.
1026  *
1027  */
1028 
1029 struct super_type  {
1030 	char		    *name;
1031 	struct module	    *owner;
1032 	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
1033 					  int minor_version);
1034 	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
1035 	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
1036 	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
1037 						sector_t num_sectors);
1038 };
1039 
1040 /*
1041  * Check that the given mddev has no bitmap.
1042  *
1043  * This function is called from the run method of all personalities that do not
1044  * support bitmaps. It prints an error message and returns non-zero if mddev
1045  * has a bitmap. Otherwise, it returns 0.
1046  *
1047  */
1048 int md_check_no_bitmap(mddev_t *mddev)
1049 {
1050 	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
1051 		return 0;
1052 	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
1053 		mdname(mddev), mddev->pers->name);
1054 	return 1;
1055 }
1056 EXPORT_SYMBOL(md_check_no_bitmap);
1057 
1058 /*
1059  * load_super for 0.90.0
1060  */
1061 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1062 {
1063 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1064 	mdp_super_t *sb;
1065 	int ret;
1066 
1067 	/*
1068 	 * Calculate the position of the superblock (512byte sectors),
1069 	 * it's at the end of the disk.
1070 	 *
1071 	 * It also happens to be a multiple of 4Kb.
1072 	 */
1073 	rdev->sb_start = calc_dev_sboffset(rdev);
1074 
1075 	ret = read_disk_sb(rdev, MD_SB_BYTES);
1076 	if (ret) return ret;
1077 
1078 	ret = -EINVAL;
1079 
1080 	bdevname(rdev->bdev, b);
1081 	sb = page_address(rdev->sb_page);
1082 
1083 	if (sb->md_magic != MD_SB_MAGIC) {
1084 		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
1085 		       b);
1086 		goto abort;
1087 	}
1088 
1089 	if (sb->major_version != 0 ||
1090 	    sb->minor_version < 90 ||
1091 	    sb->minor_version > 91) {
1092 		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
1093 			sb->major_version, sb->minor_version,
1094 			b);
1095 		goto abort;
1096 	}
1097 
1098 	if (sb->raid_disks <= 0)
1099 		goto abort;
1100 
1101 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1102 		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
1103 			b);
1104 		goto abort;
1105 	}
1106 
1107 	rdev->preferred_minor = sb->md_minor;
1108 	rdev->data_offset = 0;
1109 	rdev->sb_size = MD_SB_BYTES;
1110 	rdev->badblocks.shift = -1;
1111 
1112 	if (sb->level == LEVEL_MULTIPATH)
1113 		rdev->desc_nr = -1;
1114 	else
1115 		rdev->desc_nr = sb->this_disk.number;
1116 
1117 	if (!refdev) {
1118 		ret = 1;
1119 	} else {
1120 		__u64 ev1, ev2;
1121 		mdp_super_t *refsb = page_address(refdev->sb_page);
1122 		if (!uuid_equal(refsb, sb)) {
1123 			printk(KERN_WARNING "md: %s has different UUID to %s\n",
1124 				b, bdevname(refdev->bdev,b2));
1125 			goto abort;
1126 		}
1127 		if (!sb_equal(refsb, sb)) {
1128 			printk(KERN_WARNING "md: %s has same UUID"
1129 			       " but different superblock to %s\n",
1130 			       b, bdevname(refdev->bdev, b2));
1131 			goto abort;
1132 		}
1133 		ev1 = md_event(sb);
1134 		ev2 = md_event(refsb);
1135 		if (ev1 > ev2)
1136 			ret = 1;
1137 		else
1138 			ret = 0;
1139 	}
1140 	rdev->sectors = rdev->sb_start;
1141 
1142 	if (rdev->sectors < sb->size * 2 && sb->level > 1)
1143 		/* "this cannot possibly happen" ... */
1144 		ret = -EINVAL;
1145 
1146  abort:
1147 	return ret;
1148 }
1149 
1150 /*
1151  * validate_super for 0.90.0
1152  */
1153 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1154 {
1155 	mdp_disk_t *desc;
1156 	mdp_super_t *sb = page_address(rdev->sb_page);
1157 	__u64 ev1 = md_event(sb);
1158 
1159 	rdev->raid_disk = -1;
1160 	clear_bit(Faulty, &rdev->flags);
1161 	clear_bit(In_sync, &rdev->flags);
1162 	clear_bit(WriteMostly, &rdev->flags);
1163 
1164 	if (mddev->raid_disks == 0) {
1165 		mddev->major_version = 0;
1166 		mddev->minor_version = sb->minor_version;
1167 		mddev->patch_version = sb->patch_version;
1168 		mddev->external = 0;
1169 		mddev->chunk_sectors = sb->chunk_size >> 9;
1170 		mddev->ctime = sb->ctime;
1171 		mddev->utime = sb->utime;
1172 		mddev->level = sb->level;
1173 		mddev->clevel[0] = 0;
1174 		mddev->layout = sb->layout;
1175 		mddev->raid_disks = sb->raid_disks;
1176 		mddev->dev_sectors = sb->size * 2;
1177 		mddev->events = ev1;
1178 		mddev->bitmap_info.offset = 0;
1179 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1180 
1181 		if (mddev->minor_version >= 91) {
1182 			mddev->reshape_position = sb->reshape_position;
1183 			mddev->delta_disks = sb->delta_disks;
1184 			mddev->new_level = sb->new_level;
1185 			mddev->new_layout = sb->new_layout;
1186 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1187 		} else {
1188 			mddev->reshape_position = MaxSector;
1189 			mddev->delta_disks = 0;
1190 			mddev->new_level = mddev->level;
1191 			mddev->new_layout = mddev->layout;
1192 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1193 		}
1194 
1195 		if (sb->state & (1<<MD_SB_CLEAN))
1196 			mddev->recovery_cp = MaxSector;
1197 		else {
1198 			if (sb->events_hi == sb->cp_events_hi &&
1199 				sb->events_lo == sb->cp_events_lo) {
1200 				mddev->recovery_cp = sb->recovery_cp;
1201 			} else
1202 				mddev->recovery_cp = 0;
1203 		}
1204 
1205 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1206 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1207 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1208 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1209 
1210 		mddev->max_disks = MD_SB_DISKS;
1211 
1212 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1213 		    mddev->bitmap_info.file == NULL)
1214 			mddev->bitmap_info.offset =
1215 				mddev->bitmap_info.default_offset;
1216 
1217 	} else if (mddev->pers == NULL) {
1218 		/* Insist on good event counter while assembling, except
1219 		 * for spares (which don't need an event count) */
1220 		++ev1;
1221 		if (sb->disks[rdev->desc_nr].state & (
1222 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1223 			if (ev1 < mddev->events)
1224 				return -EINVAL;
1225 	} else if (mddev->bitmap) {
1226 		/* if adding to array with a bitmap, then we can accept an
1227 		 * older device ... but not too old.
1228 		 */
1229 		if (ev1 < mddev->bitmap->events_cleared)
1230 			return 0;
1231 	} else {
1232 		if (ev1 < mddev->events)
1233 			/* just a hot-add of a new device, leave raid_disk at -1 */
1234 			return 0;
1235 	}
1236 
1237 	if (mddev->level != LEVEL_MULTIPATH) {
1238 		desc = sb->disks + rdev->desc_nr;
1239 
1240 		if (desc->state & (1<<MD_DISK_FAULTY))
1241 			set_bit(Faulty, &rdev->flags);
1242 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1243 			    desc->raid_disk < mddev->raid_disks */) {
1244 			set_bit(In_sync, &rdev->flags);
1245 			rdev->raid_disk = desc->raid_disk;
1246 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1247 			/* active but not in sync implies recovery up to
1248 			 * reshape position.  We don't know exactly where
1249 			 * that is, so set to zero for now */
1250 			if (mddev->minor_version >= 91) {
1251 				rdev->recovery_offset = 0;
1252 				rdev->raid_disk = desc->raid_disk;
1253 			}
1254 		}
1255 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1256 			set_bit(WriteMostly, &rdev->flags);
1257 	} else /* MULTIPATH are always insync */
1258 		set_bit(In_sync, &rdev->flags);
1259 	return 0;
1260 }
1261 
1262 /*
1263  * sync_super for 0.90.0
1264  */
1265 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1266 {
1267 	mdp_super_t *sb;
1268 	mdk_rdev_t *rdev2;
1269 	int next_spare = mddev->raid_disks;
1270 
1271 
1272 	/* make rdev->sb match mddev data..
1273 	 *
1274 	 * 1/ zero out disks
1275 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1276 	 * 3/ any empty disks < next_spare become removed
1277 	 *
1278 	 * disks[0] gets initialised to REMOVED because
1279 	 * we cannot be sure from other fields if it has
1280 	 * been initialised or not.
1281 	 */
1282 	int i;
1283 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1284 
1285 	rdev->sb_size = MD_SB_BYTES;
1286 
1287 	sb = page_address(rdev->sb_page);
1288 
1289 	memset(sb, 0, sizeof(*sb));
1290 
1291 	sb->md_magic = MD_SB_MAGIC;
1292 	sb->major_version = mddev->major_version;
1293 	sb->patch_version = mddev->patch_version;
1294 	sb->gvalid_words  = 0; /* ignored */
1295 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1296 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1297 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1298 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1299 
1300 	sb->ctime = mddev->ctime;
1301 	sb->level = mddev->level;
1302 	sb->size = mddev->dev_sectors / 2;
1303 	sb->raid_disks = mddev->raid_disks;
1304 	sb->md_minor = mddev->md_minor;
1305 	sb->not_persistent = 0;
1306 	sb->utime = mddev->utime;
1307 	sb->state = 0;
1308 	sb->events_hi = (mddev->events>>32);
1309 	sb->events_lo = (u32)mddev->events;
1310 
1311 	if (mddev->reshape_position == MaxSector)
1312 		sb->minor_version = 90;
1313 	else {
1314 		sb->minor_version = 91;
1315 		sb->reshape_position = mddev->reshape_position;
1316 		sb->new_level = mddev->new_level;
1317 		sb->delta_disks = mddev->delta_disks;
1318 		sb->new_layout = mddev->new_layout;
1319 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1320 	}
1321 	mddev->minor_version = sb->minor_version;
1322 	if (mddev->in_sync)
1323 	{
1324 		sb->recovery_cp = mddev->recovery_cp;
1325 		sb->cp_events_hi = (mddev->events>>32);
1326 		sb->cp_events_lo = (u32)mddev->events;
1327 		if (mddev->recovery_cp == MaxSector)
1328 			sb->state = (1<< MD_SB_CLEAN);
1329 	} else
1330 		sb->recovery_cp = 0;
1331 
1332 	sb->layout = mddev->layout;
1333 	sb->chunk_size = mddev->chunk_sectors << 9;
1334 
1335 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1336 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1337 
1338 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1339 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1340 		mdp_disk_t *d;
1341 		int desc_nr;
1342 		int is_active = test_bit(In_sync, &rdev2->flags);
1343 
1344 		if (rdev2->raid_disk >= 0 &&
1345 		    sb->minor_version >= 91)
1346 			/* we have nowhere to store the recovery_offset,
1347 			 * but if it is not below the reshape_position,
1348 			 * we can piggy-back on that.
1349 			 */
1350 			is_active = 1;
1351 		if (rdev2->raid_disk < 0 ||
1352 		    test_bit(Faulty, &rdev2->flags))
1353 			is_active = 0;
1354 		if (is_active)
1355 			desc_nr = rdev2->raid_disk;
1356 		else
1357 			desc_nr = next_spare++;
1358 		rdev2->desc_nr = desc_nr;
1359 		d = &sb->disks[rdev2->desc_nr];
1360 		nr_disks++;
1361 		d->number = rdev2->desc_nr;
1362 		d->major = MAJOR(rdev2->bdev->bd_dev);
1363 		d->minor = MINOR(rdev2->bdev->bd_dev);
1364 		if (is_active)
1365 			d->raid_disk = rdev2->raid_disk;
1366 		else
1367 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1368 		if (test_bit(Faulty, &rdev2->flags))
1369 			d->state = (1<<MD_DISK_FAULTY);
1370 		else if (is_active) {
1371 			d->state = (1<<MD_DISK_ACTIVE);
1372 			if (test_bit(In_sync, &rdev2->flags))
1373 				d->state |= (1<<MD_DISK_SYNC);
1374 			active++;
1375 			working++;
1376 		} else {
1377 			d->state = 0;
1378 			spare++;
1379 			working++;
1380 		}
1381 		if (test_bit(WriteMostly, &rdev2->flags))
1382 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1383 	}
1384 	/* now set the "removed" and "faulty" bits on any missing devices */
1385 	for (i=0 ; i < mddev->raid_disks ; i++) {
1386 		mdp_disk_t *d = &sb->disks[i];
1387 		if (d->state == 0 && d->number == 0) {
1388 			d->number = i;
1389 			d->raid_disk = i;
1390 			d->state = (1<<MD_DISK_REMOVED);
1391 			d->state |= (1<<MD_DISK_FAULTY);
1392 			failed++;
1393 		}
1394 	}
1395 	sb->nr_disks = nr_disks;
1396 	sb->active_disks = active;
1397 	sb->working_disks = working;
1398 	sb->failed_disks = failed;
1399 	sb->spare_disks = spare;
1400 
1401 	sb->this_disk = sb->disks[rdev->desc_nr];
1402 	sb->sb_csum = calc_sb_csum(sb);
1403 }
1404 
1405 /*
1406  * rdev_size_change for 0.90.0
1407  */
1408 static unsigned long long
1409 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1410 {
1411 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1412 		return 0; /* component must fit device */
1413 	if (rdev->mddev->bitmap_info.offset)
1414 		return 0; /* can't move bitmap */
1415 	rdev->sb_start = calc_dev_sboffset(rdev);
1416 	if (!num_sectors || num_sectors > rdev->sb_start)
1417 		num_sectors = rdev->sb_start;
1418 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1419 		       rdev->sb_page);
1420 	md_super_wait(rdev->mddev);
1421 	return num_sectors;
1422 }
1423 
1424 
1425 /*
1426  * version 1 superblock
1427  */
1428 
1429 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1430 {
1431 	__le32 disk_csum;
1432 	u32 csum;
1433 	unsigned long long newcsum;
1434 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1435 	__le32 *isuper = (__le32*)sb;
1436 	int i;
1437 
1438 	disk_csum = sb->sb_csum;
1439 	sb->sb_csum = 0;
1440 	newcsum = 0;
1441 	for (i=0; size>=4; size -= 4 )
1442 		newcsum += le32_to_cpu(*isuper++);
1443 
1444 	if (size == 2)
1445 		newcsum += le16_to_cpu(*(__le16*) isuper);
1446 
1447 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1448 	sb->sb_csum = disk_csum;
1449 	return cpu_to_le32(csum);
1450 }
1451 
1452 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1453 			    int acknowledged);
1454 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1455 {
1456 	struct mdp_superblock_1 *sb;
1457 	int ret;
1458 	sector_t sb_start;
1459 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1460 	int bmask;
1461 
1462 	/*
1463 	 * Calculate the position of the superblock in 512byte sectors.
1464 	 * It is always aligned to a 4K boundary and
1465 	 * depeding on minor_version, it can be:
1466 	 * 0: At least 8K, but less than 12K, from end of device
1467 	 * 1: At start of device
1468 	 * 2: 4K from start of device.
1469 	 */
1470 	switch(minor_version) {
1471 	case 0:
1472 		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1473 		sb_start -= 8*2;
1474 		sb_start &= ~(sector_t)(4*2-1);
1475 		break;
1476 	case 1:
1477 		sb_start = 0;
1478 		break;
1479 	case 2:
1480 		sb_start = 8;
1481 		break;
1482 	default:
1483 		return -EINVAL;
1484 	}
1485 	rdev->sb_start = sb_start;
1486 
1487 	/* superblock is rarely larger than 1K, but it can be larger,
1488 	 * and it is safe to read 4k, so we do that
1489 	 */
1490 	ret = read_disk_sb(rdev, 4096);
1491 	if (ret) return ret;
1492 
1493 
1494 	sb = page_address(rdev->sb_page);
1495 
1496 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1497 	    sb->major_version != cpu_to_le32(1) ||
1498 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1499 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1500 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1501 		return -EINVAL;
1502 
1503 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1504 		printk("md: invalid superblock checksum on %s\n",
1505 			bdevname(rdev->bdev,b));
1506 		return -EINVAL;
1507 	}
1508 	if (le64_to_cpu(sb->data_size) < 10) {
1509 		printk("md: data_size too small on %s\n",
1510 		       bdevname(rdev->bdev,b));
1511 		return -EINVAL;
1512 	}
1513 
1514 	rdev->preferred_minor = 0xffff;
1515 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1516 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1517 
1518 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1519 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1520 	if (rdev->sb_size & bmask)
1521 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1522 
1523 	if (minor_version
1524 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1525 		return -EINVAL;
1526 
1527 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1528 		rdev->desc_nr = -1;
1529 	else
1530 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1531 
1532 	if (!rdev->bb_page) {
1533 		rdev->bb_page = alloc_page(GFP_KERNEL);
1534 		if (!rdev->bb_page)
1535 			return -ENOMEM;
1536 	}
1537 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1538 	    rdev->badblocks.count == 0) {
1539 		/* need to load the bad block list.
1540 		 * Currently we limit it to one page.
1541 		 */
1542 		s32 offset;
1543 		sector_t bb_sector;
1544 		u64 *bbp;
1545 		int i;
1546 		int sectors = le16_to_cpu(sb->bblog_size);
1547 		if (sectors > (PAGE_SIZE / 512))
1548 			return -EINVAL;
1549 		offset = le32_to_cpu(sb->bblog_offset);
1550 		if (offset == 0)
1551 			return -EINVAL;
1552 		bb_sector = (long long)offset;
1553 		if (!sync_page_io(rdev, bb_sector, sectors << 9,
1554 				  rdev->bb_page, READ, true))
1555 			return -EIO;
1556 		bbp = (u64 *)page_address(rdev->bb_page);
1557 		rdev->badblocks.shift = sb->bblog_shift;
1558 		for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1559 			u64 bb = le64_to_cpu(*bbp);
1560 			int count = bb & (0x3ff);
1561 			u64 sector = bb >> 10;
1562 			sector <<= sb->bblog_shift;
1563 			count <<= sb->bblog_shift;
1564 			if (bb + 1 == 0)
1565 				break;
1566 			if (md_set_badblocks(&rdev->badblocks,
1567 					     sector, count, 1) == 0)
1568 				return -EINVAL;
1569 		}
1570 	} else if (sb->bblog_offset == 0)
1571 		rdev->badblocks.shift = -1;
1572 
1573 	if (!refdev) {
1574 		ret = 1;
1575 	} else {
1576 		__u64 ev1, ev2;
1577 		struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1578 
1579 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1580 		    sb->level != refsb->level ||
1581 		    sb->layout != refsb->layout ||
1582 		    sb->chunksize != refsb->chunksize) {
1583 			printk(KERN_WARNING "md: %s has strangely different"
1584 				" superblock to %s\n",
1585 				bdevname(rdev->bdev,b),
1586 				bdevname(refdev->bdev,b2));
1587 			return -EINVAL;
1588 		}
1589 		ev1 = le64_to_cpu(sb->events);
1590 		ev2 = le64_to_cpu(refsb->events);
1591 
1592 		if (ev1 > ev2)
1593 			ret = 1;
1594 		else
1595 			ret = 0;
1596 	}
1597 	if (minor_version)
1598 		rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
1599 			le64_to_cpu(sb->data_offset);
1600 	else
1601 		rdev->sectors = rdev->sb_start;
1602 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1603 		return -EINVAL;
1604 	rdev->sectors = le64_to_cpu(sb->data_size);
1605 	if (le64_to_cpu(sb->size) > rdev->sectors)
1606 		return -EINVAL;
1607 	return ret;
1608 }
1609 
1610 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1611 {
1612 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1613 	__u64 ev1 = le64_to_cpu(sb->events);
1614 
1615 	rdev->raid_disk = -1;
1616 	clear_bit(Faulty, &rdev->flags);
1617 	clear_bit(In_sync, &rdev->flags);
1618 	clear_bit(WriteMostly, &rdev->flags);
1619 
1620 	if (mddev->raid_disks == 0) {
1621 		mddev->major_version = 1;
1622 		mddev->patch_version = 0;
1623 		mddev->external = 0;
1624 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1625 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1626 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1627 		mddev->level = le32_to_cpu(sb->level);
1628 		mddev->clevel[0] = 0;
1629 		mddev->layout = le32_to_cpu(sb->layout);
1630 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1631 		mddev->dev_sectors = le64_to_cpu(sb->size);
1632 		mddev->events = ev1;
1633 		mddev->bitmap_info.offset = 0;
1634 		mddev->bitmap_info.default_offset = 1024 >> 9;
1635 
1636 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1637 		memcpy(mddev->uuid, sb->set_uuid, 16);
1638 
1639 		mddev->max_disks =  (4096-256)/2;
1640 
1641 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1642 		    mddev->bitmap_info.file == NULL )
1643 			mddev->bitmap_info.offset =
1644 				(__s32)le32_to_cpu(sb->bitmap_offset);
1645 
1646 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1647 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1648 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1649 			mddev->new_level = le32_to_cpu(sb->new_level);
1650 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1651 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1652 		} else {
1653 			mddev->reshape_position = MaxSector;
1654 			mddev->delta_disks = 0;
1655 			mddev->new_level = mddev->level;
1656 			mddev->new_layout = mddev->layout;
1657 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1658 		}
1659 
1660 	} else if (mddev->pers == NULL) {
1661 		/* Insist of good event counter while assembling, except for
1662 		 * spares (which don't need an event count) */
1663 		++ev1;
1664 		if (rdev->desc_nr >= 0 &&
1665 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1666 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1667 			if (ev1 < mddev->events)
1668 				return -EINVAL;
1669 	} else if (mddev->bitmap) {
1670 		/* If adding to array with a bitmap, then we can accept an
1671 		 * older device, but not too old.
1672 		 */
1673 		if (ev1 < mddev->bitmap->events_cleared)
1674 			return 0;
1675 	} else {
1676 		if (ev1 < mddev->events)
1677 			/* just a hot-add of a new device, leave raid_disk at -1 */
1678 			return 0;
1679 	}
1680 	if (mddev->level != LEVEL_MULTIPATH) {
1681 		int role;
1682 		if (rdev->desc_nr < 0 ||
1683 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1684 			role = 0xffff;
1685 			rdev->desc_nr = -1;
1686 		} else
1687 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1688 		switch(role) {
1689 		case 0xffff: /* spare */
1690 			break;
1691 		case 0xfffe: /* faulty */
1692 			set_bit(Faulty, &rdev->flags);
1693 			break;
1694 		default:
1695 			if ((le32_to_cpu(sb->feature_map) &
1696 			     MD_FEATURE_RECOVERY_OFFSET))
1697 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1698 			else
1699 				set_bit(In_sync, &rdev->flags);
1700 			rdev->raid_disk = role;
1701 			break;
1702 		}
1703 		if (sb->devflags & WriteMostly1)
1704 			set_bit(WriteMostly, &rdev->flags);
1705 	} else /* MULTIPATH are always insync */
1706 		set_bit(In_sync, &rdev->flags);
1707 
1708 	return 0;
1709 }
1710 
1711 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1712 {
1713 	struct mdp_superblock_1 *sb;
1714 	mdk_rdev_t *rdev2;
1715 	int max_dev, i;
1716 	/* make rdev->sb match mddev and rdev data. */
1717 
1718 	sb = page_address(rdev->sb_page);
1719 
1720 	sb->feature_map = 0;
1721 	sb->pad0 = 0;
1722 	sb->recovery_offset = cpu_to_le64(0);
1723 	memset(sb->pad1, 0, sizeof(sb->pad1));
1724 	memset(sb->pad3, 0, sizeof(sb->pad3));
1725 
1726 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1727 	sb->events = cpu_to_le64(mddev->events);
1728 	if (mddev->in_sync)
1729 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1730 	else
1731 		sb->resync_offset = cpu_to_le64(0);
1732 
1733 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1734 
1735 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1736 	sb->size = cpu_to_le64(mddev->dev_sectors);
1737 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1738 	sb->level = cpu_to_le32(mddev->level);
1739 	sb->layout = cpu_to_le32(mddev->layout);
1740 
1741 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1742 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1743 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1744 	}
1745 
1746 	if (rdev->raid_disk >= 0 &&
1747 	    !test_bit(In_sync, &rdev->flags)) {
1748 		sb->feature_map |=
1749 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1750 		sb->recovery_offset =
1751 			cpu_to_le64(rdev->recovery_offset);
1752 	}
1753 
1754 	if (mddev->reshape_position != MaxSector) {
1755 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1756 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1757 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1758 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1759 		sb->new_level = cpu_to_le32(mddev->new_level);
1760 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1761 	}
1762 
1763 	if (rdev->badblocks.count == 0)
1764 		/* Nothing to do for bad blocks*/ ;
1765 	else if (sb->bblog_offset == 0)
1766 		/* Cannot record bad blocks on this device */
1767 		md_error(mddev, rdev);
1768 	else {
1769 		struct badblocks *bb = &rdev->badblocks;
1770 		u64 *bbp = (u64 *)page_address(rdev->bb_page);
1771 		u64 *p = bb->page;
1772 		sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1773 		if (bb->changed) {
1774 			unsigned seq;
1775 
1776 retry:
1777 			seq = read_seqbegin(&bb->lock);
1778 
1779 			memset(bbp, 0xff, PAGE_SIZE);
1780 
1781 			for (i = 0 ; i < bb->count ; i++) {
1782 				u64 internal_bb = *p++;
1783 				u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1784 						| BB_LEN(internal_bb));
1785 				*bbp++ = cpu_to_le64(store_bb);
1786 			}
1787 			if (read_seqretry(&bb->lock, seq))
1788 				goto retry;
1789 
1790 			bb->sector = (rdev->sb_start +
1791 				      (int)le32_to_cpu(sb->bblog_offset));
1792 			bb->size = le16_to_cpu(sb->bblog_size);
1793 			bb->changed = 0;
1794 		}
1795 	}
1796 
1797 	max_dev = 0;
1798 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1799 		if (rdev2->desc_nr+1 > max_dev)
1800 			max_dev = rdev2->desc_nr+1;
1801 
1802 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1803 		int bmask;
1804 		sb->max_dev = cpu_to_le32(max_dev);
1805 		rdev->sb_size = max_dev * 2 + 256;
1806 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1807 		if (rdev->sb_size & bmask)
1808 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1809 	} else
1810 		max_dev = le32_to_cpu(sb->max_dev);
1811 
1812 	for (i=0; i<max_dev;i++)
1813 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1814 
1815 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1816 		i = rdev2->desc_nr;
1817 		if (test_bit(Faulty, &rdev2->flags))
1818 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1819 		else if (test_bit(In_sync, &rdev2->flags))
1820 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1821 		else if (rdev2->raid_disk >= 0)
1822 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1823 		else
1824 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1825 	}
1826 
1827 	sb->sb_csum = calc_sb_1_csum(sb);
1828 }
1829 
1830 static unsigned long long
1831 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1832 {
1833 	struct mdp_superblock_1 *sb;
1834 	sector_t max_sectors;
1835 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1836 		return 0; /* component must fit device */
1837 	if (rdev->sb_start < rdev->data_offset) {
1838 		/* minor versions 1 and 2; superblock before data */
1839 		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1840 		max_sectors -= rdev->data_offset;
1841 		if (!num_sectors || num_sectors > max_sectors)
1842 			num_sectors = max_sectors;
1843 	} else if (rdev->mddev->bitmap_info.offset) {
1844 		/* minor version 0 with bitmap we can't move */
1845 		return 0;
1846 	} else {
1847 		/* minor version 0; superblock after data */
1848 		sector_t sb_start;
1849 		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1850 		sb_start &= ~(sector_t)(4*2 - 1);
1851 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1852 		if (!num_sectors || num_sectors > max_sectors)
1853 			num_sectors = max_sectors;
1854 		rdev->sb_start = sb_start;
1855 	}
1856 	sb = page_address(rdev->sb_page);
1857 	sb->data_size = cpu_to_le64(num_sectors);
1858 	sb->super_offset = rdev->sb_start;
1859 	sb->sb_csum = calc_sb_1_csum(sb);
1860 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1861 		       rdev->sb_page);
1862 	md_super_wait(rdev->mddev);
1863 	return num_sectors;
1864 }
1865 
1866 static struct super_type super_types[] = {
1867 	[0] = {
1868 		.name	= "0.90.0",
1869 		.owner	= THIS_MODULE,
1870 		.load_super	    = super_90_load,
1871 		.validate_super	    = super_90_validate,
1872 		.sync_super	    = super_90_sync,
1873 		.rdev_size_change   = super_90_rdev_size_change,
1874 	},
1875 	[1] = {
1876 		.name	= "md-1",
1877 		.owner	= THIS_MODULE,
1878 		.load_super	    = super_1_load,
1879 		.validate_super	    = super_1_validate,
1880 		.sync_super	    = super_1_sync,
1881 		.rdev_size_change   = super_1_rdev_size_change,
1882 	},
1883 };
1884 
1885 static void sync_super(mddev_t *mddev, mdk_rdev_t *rdev)
1886 {
1887 	if (mddev->sync_super) {
1888 		mddev->sync_super(mddev, rdev);
1889 		return;
1890 	}
1891 
1892 	BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1893 
1894 	super_types[mddev->major_version].sync_super(mddev, rdev);
1895 }
1896 
1897 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1898 {
1899 	mdk_rdev_t *rdev, *rdev2;
1900 
1901 	rcu_read_lock();
1902 	rdev_for_each_rcu(rdev, mddev1)
1903 		rdev_for_each_rcu(rdev2, mddev2)
1904 			if (rdev->bdev->bd_contains ==
1905 			    rdev2->bdev->bd_contains) {
1906 				rcu_read_unlock();
1907 				return 1;
1908 			}
1909 	rcu_read_unlock();
1910 	return 0;
1911 }
1912 
1913 static LIST_HEAD(pending_raid_disks);
1914 
1915 /*
1916  * Try to register data integrity profile for an mddev
1917  *
1918  * This is called when an array is started and after a disk has been kicked
1919  * from the array. It only succeeds if all working and active component devices
1920  * are integrity capable with matching profiles.
1921  */
1922 int md_integrity_register(mddev_t *mddev)
1923 {
1924 	mdk_rdev_t *rdev, *reference = NULL;
1925 
1926 	if (list_empty(&mddev->disks))
1927 		return 0; /* nothing to do */
1928 	if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1929 		return 0; /* shouldn't register, or already is */
1930 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1931 		/* skip spares and non-functional disks */
1932 		if (test_bit(Faulty, &rdev->flags))
1933 			continue;
1934 		if (rdev->raid_disk < 0)
1935 			continue;
1936 		if (!reference) {
1937 			/* Use the first rdev as the reference */
1938 			reference = rdev;
1939 			continue;
1940 		}
1941 		/* does this rdev's profile match the reference profile? */
1942 		if (blk_integrity_compare(reference->bdev->bd_disk,
1943 				rdev->bdev->bd_disk) < 0)
1944 			return -EINVAL;
1945 	}
1946 	if (!reference || !bdev_get_integrity(reference->bdev))
1947 		return 0;
1948 	/*
1949 	 * All component devices are integrity capable and have matching
1950 	 * profiles, register the common profile for the md device.
1951 	 */
1952 	if (blk_integrity_register(mddev->gendisk,
1953 			bdev_get_integrity(reference->bdev)) != 0) {
1954 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1955 			mdname(mddev));
1956 		return -EINVAL;
1957 	}
1958 	printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
1959 	if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
1960 		printk(KERN_ERR "md: failed to create integrity pool for %s\n",
1961 		       mdname(mddev));
1962 		return -EINVAL;
1963 	}
1964 	return 0;
1965 }
1966 EXPORT_SYMBOL(md_integrity_register);
1967 
1968 /* Disable data integrity if non-capable/non-matching disk is being added */
1969 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1970 {
1971 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1972 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1973 
1974 	if (!bi_mddev) /* nothing to do */
1975 		return;
1976 	if (rdev->raid_disk < 0) /* skip spares */
1977 		return;
1978 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1979 					     rdev->bdev->bd_disk) >= 0)
1980 		return;
1981 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1982 	blk_integrity_unregister(mddev->gendisk);
1983 }
1984 EXPORT_SYMBOL(md_integrity_add_rdev);
1985 
1986 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1987 {
1988 	char b[BDEVNAME_SIZE];
1989 	struct kobject *ko;
1990 	char *s;
1991 	int err;
1992 
1993 	if (rdev->mddev) {
1994 		MD_BUG();
1995 		return -EINVAL;
1996 	}
1997 
1998 	/* prevent duplicates */
1999 	if (find_rdev(mddev, rdev->bdev->bd_dev))
2000 		return -EEXIST;
2001 
2002 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
2003 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
2004 			rdev->sectors < mddev->dev_sectors)) {
2005 		if (mddev->pers) {
2006 			/* Cannot change size, so fail
2007 			 * If mddev->level <= 0, then we don't care
2008 			 * about aligning sizes (e.g. linear)
2009 			 */
2010 			if (mddev->level > 0)
2011 				return -ENOSPC;
2012 		} else
2013 			mddev->dev_sectors = rdev->sectors;
2014 	}
2015 
2016 	/* Verify rdev->desc_nr is unique.
2017 	 * If it is -1, assign a free number, else
2018 	 * check number is not in use
2019 	 */
2020 	if (rdev->desc_nr < 0) {
2021 		int choice = 0;
2022 		if (mddev->pers) choice = mddev->raid_disks;
2023 		while (find_rdev_nr(mddev, choice))
2024 			choice++;
2025 		rdev->desc_nr = choice;
2026 	} else {
2027 		if (find_rdev_nr(mddev, rdev->desc_nr))
2028 			return -EBUSY;
2029 	}
2030 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2031 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2032 		       mdname(mddev), mddev->max_disks);
2033 		return -EBUSY;
2034 	}
2035 	bdevname(rdev->bdev,b);
2036 	while ( (s=strchr(b, '/')) != NULL)
2037 		*s = '!';
2038 
2039 	rdev->mddev = mddev;
2040 	printk(KERN_INFO "md: bind<%s>\n", b);
2041 
2042 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2043 		goto fail;
2044 
2045 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2046 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
2047 		/* failure here is OK */;
2048 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2049 
2050 	list_add_rcu(&rdev->same_set, &mddev->disks);
2051 	bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2052 
2053 	/* May as well allow recovery to be retried once */
2054 	mddev->recovery_disabled++;
2055 
2056 	return 0;
2057 
2058  fail:
2059 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2060 	       b, mdname(mddev));
2061 	return err;
2062 }
2063 
2064 static void md_delayed_delete(struct work_struct *ws)
2065 {
2066 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
2067 	kobject_del(&rdev->kobj);
2068 	kobject_put(&rdev->kobj);
2069 }
2070 
2071 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
2072 {
2073 	char b[BDEVNAME_SIZE];
2074 	if (!rdev->mddev) {
2075 		MD_BUG();
2076 		return;
2077 	}
2078 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2079 	list_del_rcu(&rdev->same_set);
2080 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2081 	rdev->mddev = NULL;
2082 	sysfs_remove_link(&rdev->kobj, "block");
2083 	sysfs_put(rdev->sysfs_state);
2084 	rdev->sysfs_state = NULL;
2085 	kfree(rdev->badblocks.page);
2086 	rdev->badblocks.count = 0;
2087 	rdev->badblocks.page = NULL;
2088 	/* We need to delay this, otherwise we can deadlock when
2089 	 * writing to 'remove' to "dev/state".  We also need
2090 	 * to delay it due to rcu usage.
2091 	 */
2092 	synchronize_rcu();
2093 	INIT_WORK(&rdev->del_work, md_delayed_delete);
2094 	kobject_get(&rdev->kobj);
2095 	queue_work(md_misc_wq, &rdev->del_work);
2096 }
2097 
2098 /*
2099  * prevent the device from being mounted, repartitioned or
2100  * otherwise reused by a RAID array (or any other kernel
2101  * subsystem), by bd_claiming the device.
2102  */
2103 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
2104 {
2105 	int err = 0;
2106 	struct block_device *bdev;
2107 	char b[BDEVNAME_SIZE];
2108 
2109 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2110 				 shared ? (mdk_rdev_t *)lock_rdev : rdev);
2111 	if (IS_ERR(bdev)) {
2112 		printk(KERN_ERR "md: could not open %s.\n",
2113 			__bdevname(dev, b));
2114 		return PTR_ERR(bdev);
2115 	}
2116 	rdev->bdev = bdev;
2117 	return err;
2118 }
2119 
2120 static void unlock_rdev(mdk_rdev_t *rdev)
2121 {
2122 	struct block_device *bdev = rdev->bdev;
2123 	rdev->bdev = NULL;
2124 	if (!bdev)
2125 		MD_BUG();
2126 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2127 }
2128 
2129 void md_autodetect_dev(dev_t dev);
2130 
2131 static void export_rdev(mdk_rdev_t * rdev)
2132 {
2133 	char b[BDEVNAME_SIZE];
2134 	printk(KERN_INFO "md: export_rdev(%s)\n",
2135 		bdevname(rdev->bdev,b));
2136 	if (rdev->mddev)
2137 		MD_BUG();
2138 	free_disk_sb(rdev);
2139 #ifndef MODULE
2140 	if (test_bit(AutoDetected, &rdev->flags))
2141 		md_autodetect_dev(rdev->bdev->bd_dev);
2142 #endif
2143 	unlock_rdev(rdev);
2144 	kobject_put(&rdev->kobj);
2145 }
2146 
2147 static void kick_rdev_from_array(mdk_rdev_t * rdev)
2148 {
2149 	unbind_rdev_from_array(rdev);
2150 	export_rdev(rdev);
2151 }
2152 
2153 static void export_array(mddev_t *mddev)
2154 {
2155 	mdk_rdev_t *rdev, *tmp;
2156 
2157 	rdev_for_each(rdev, tmp, mddev) {
2158 		if (!rdev->mddev) {
2159 			MD_BUG();
2160 			continue;
2161 		}
2162 		kick_rdev_from_array(rdev);
2163 	}
2164 	if (!list_empty(&mddev->disks))
2165 		MD_BUG();
2166 	mddev->raid_disks = 0;
2167 	mddev->major_version = 0;
2168 }
2169 
2170 static void print_desc(mdp_disk_t *desc)
2171 {
2172 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2173 		desc->major,desc->minor,desc->raid_disk,desc->state);
2174 }
2175 
2176 static void print_sb_90(mdp_super_t *sb)
2177 {
2178 	int i;
2179 
2180 	printk(KERN_INFO
2181 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2182 		sb->major_version, sb->minor_version, sb->patch_version,
2183 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2184 		sb->ctime);
2185 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2186 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2187 		sb->md_minor, sb->layout, sb->chunk_size);
2188 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2189 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2190 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2191 		sb->failed_disks, sb->spare_disks,
2192 		sb->sb_csum, (unsigned long)sb->events_lo);
2193 
2194 	printk(KERN_INFO);
2195 	for (i = 0; i < MD_SB_DISKS; i++) {
2196 		mdp_disk_t *desc;
2197 
2198 		desc = sb->disks + i;
2199 		if (desc->number || desc->major || desc->minor ||
2200 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2201 			printk("     D %2d: ", i);
2202 			print_desc(desc);
2203 		}
2204 	}
2205 	printk(KERN_INFO "md:     THIS: ");
2206 	print_desc(&sb->this_disk);
2207 }
2208 
2209 static void print_sb_1(struct mdp_superblock_1 *sb)
2210 {
2211 	__u8 *uuid;
2212 
2213 	uuid = sb->set_uuid;
2214 	printk(KERN_INFO
2215 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2216 	       "md:    Name: \"%s\" CT:%llu\n",
2217 		le32_to_cpu(sb->major_version),
2218 		le32_to_cpu(sb->feature_map),
2219 		uuid,
2220 		sb->set_name,
2221 		(unsigned long long)le64_to_cpu(sb->ctime)
2222 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2223 
2224 	uuid = sb->device_uuid;
2225 	printk(KERN_INFO
2226 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2227 			" RO:%llu\n"
2228 	       "md:     Dev:%08x UUID: %pU\n"
2229 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2230 	       "md:         (MaxDev:%u) \n",
2231 		le32_to_cpu(sb->level),
2232 		(unsigned long long)le64_to_cpu(sb->size),
2233 		le32_to_cpu(sb->raid_disks),
2234 		le32_to_cpu(sb->layout),
2235 		le32_to_cpu(sb->chunksize),
2236 		(unsigned long long)le64_to_cpu(sb->data_offset),
2237 		(unsigned long long)le64_to_cpu(sb->data_size),
2238 		(unsigned long long)le64_to_cpu(sb->super_offset),
2239 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2240 		le32_to_cpu(sb->dev_number),
2241 		uuid,
2242 		sb->devflags,
2243 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2244 		(unsigned long long)le64_to_cpu(sb->events),
2245 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2246 		le32_to_cpu(sb->sb_csum),
2247 		le32_to_cpu(sb->max_dev)
2248 		);
2249 }
2250 
2251 static void print_rdev(mdk_rdev_t *rdev, int major_version)
2252 {
2253 	char b[BDEVNAME_SIZE];
2254 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2255 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2256 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2257 	        rdev->desc_nr);
2258 	if (rdev->sb_loaded) {
2259 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2260 		switch (major_version) {
2261 		case 0:
2262 			print_sb_90(page_address(rdev->sb_page));
2263 			break;
2264 		case 1:
2265 			print_sb_1(page_address(rdev->sb_page));
2266 			break;
2267 		}
2268 	} else
2269 		printk(KERN_INFO "md: no rdev superblock!\n");
2270 }
2271 
2272 static void md_print_devices(void)
2273 {
2274 	struct list_head *tmp;
2275 	mdk_rdev_t *rdev;
2276 	mddev_t *mddev;
2277 	char b[BDEVNAME_SIZE];
2278 
2279 	printk("\n");
2280 	printk("md:	**********************************\n");
2281 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2282 	printk("md:	**********************************\n");
2283 	for_each_mddev(mddev, tmp) {
2284 
2285 		if (mddev->bitmap)
2286 			bitmap_print_sb(mddev->bitmap);
2287 		else
2288 			printk("%s: ", mdname(mddev));
2289 		list_for_each_entry(rdev, &mddev->disks, same_set)
2290 			printk("<%s>", bdevname(rdev->bdev,b));
2291 		printk("\n");
2292 
2293 		list_for_each_entry(rdev, &mddev->disks, same_set)
2294 			print_rdev(rdev, mddev->major_version);
2295 	}
2296 	printk("md:	**********************************\n");
2297 	printk("\n");
2298 }
2299 
2300 
2301 static void sync_sbs(mddev_t * mddev, int nospares)
2302 {
2303 	/* Update each superblock (in-memory image), but
2304 	 * if we are allowed to, skip spares which already
2305 	 * have the right event counter, or have one earlier
2306 	 * (which would mean they aren't being marked as dirty
2307 	 * with the rest of the array)
2308 	 */
2309 	mdk_rdev_t *rdev;
2310 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2311 		if (rdev->sb_events == mddev->events ||
2312 		    (nospares &&
2313 		     rdev->raid_disk < 0 &&
2314 		     rdev->sb_events+1 == mddev->events)) {
2315 			/* Don't update this superblock */
2316 			rdev->sb_loaded = 2;
2317 		} else {
2318 			sync_super(mddev, rdev);
2319 			rdev->sb_loaded = 1;
2320 		}
2321 	}
2322 }
2323 
2324 static void md_update_sb(mddev_t * mddev, int force_change)
2325 {
2326 	mdk_rdev_t *rdev;
2327 	int sync_req;
2328 	int nospares = 0;
2329 	int any_badblocks_changed = 0;
2330 
2331 repeat:
2332 	/* First make sure individual recovery_offsets are correct */
2333 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2334 		if (rdev->raid_disk >= 0 &&
2335 		    mddev->delta_disks >= 0 &&
2336 		    !test_bit(In_sync, &rdev->flags) &&
2337 		    mddev->curr_resync_completed > rdev->recovery_offset)
2338 				rdev->recovery_offset = mddev->curr_resync_completed;
2339 
2340 	}
2341 	if (!mddev->persistent) {
2342 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2343 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2344 		if (!mddev->external) {
2345 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2346 			list_for_each_entry(rdev, &mddev->disks, same_set) {
2347 				if (rdev->badblocks.changed) {
2348 					md_ack_all_badblocks(&rdev->badblocks);
2349 					md_error(mddev, rdev);
2350 				}
2351 				clear_bit(Blocked, &rdev->flags);
2352 				clear_bit(BlockedBadBlocks, &rdev->flags);
2353 				wake_up(&rdev->blocked_wait);
2354 			}
2355 		}
2356 		wake_up(&mddev->sb_wait);
2357 		return;
2358 	}
2359 
2360 	spin_lock_irq(&mddev->write_lock);
2361 
2362 	mddev->utime = get_seconds();
2363 
2364 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2365 		force_change = 1;
2366 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2367 		/* just a clean<-> dirty transition, possibly leave spares alone,
2368 		 * though if events isn't the right even/odd, we will have to do
2369 		 * spares after all
2370 		 */
2371 		nospares = 1;
2372 	if (force_change)
2373 		nospares = 0;
2374 	if (mddev->degraded)
2375 		/* If the array is degraded, then skipping spares is both
2376 		 * dangerous and fairly pointless.
2377 		 * Dangerous because a device that was removed from the array
2378 		 * might have a event_count that still looks up-to-date,
2379 		 * so it can be re-added without a resync.
2380 		 * Pointless because if there are any spares to skip,
2381 		 * then a recovery will happen and soon that array won't
2382 		 * be degraded any more and the spare can go back to sleep then.
2383 		 */
2384 		nospares = 0;
2385 
2386 	sync_req = mddev->in_sync;
2387 
2388 	/* If this is just a dirty<->clean transition, and the array is clean
2389 	 * and 'events' is odd, we can roll back to the previous clean state */
2390 	if (nospares
2391 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2392 	    && mddev->can_decrease_events
2393 	    && mddev->events != 1) {
2394 		mddev->events--;
2395 		mddev->can_decrease_events = 0;
2396 	} else {
2397 		/* otherwise we have to go forward and ... */
2398 		mddev->events ++;
2399 		mddev->can_decrease_events = nospares;
2400 	}
2401 
2402 	if (!mddev->events) {
2403 		/*
2404 		 * oops, this 64-bit counter should never wrap.
2405 		 * Either we are in around ~1 trillion A.C., assuming
2406 		 * 1 reboot per second, or we have a bug:
2407 		 */
2408 		MD_BUG();
2409 		mddev->events --;
2410 	}
2411 
2412 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2413 		if (rdev->badblocks.changed)
2414 			any_badblocks_changed++;
2415 		if (test_bit(Faulty, &rdev->flags))
2416 			set_bit(FaultRecorded, &rdev->flags);
2417 	}
2418 
2419 	sync_sbs(mddev, nospares);
2420 	spin_unlock_irq(&mddev->write_lock);
2421 
2422 	dprintk(KERN_INFO
2423 		"md: updating %s RAID superblock on device (in sync %d)\n",
2424 		mdname(mddev),mddev->in_sync);
2425 
2426 	bitmap_update_sb(mddev->bitmap);
2427 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2428 		char b[BDEVNAME_SIZE];
2429 		dprintk(KERN_INFO "md: ");
2430 		if (rdev->sb_loaded != 1)
2431 			continue; /* no noise on spare devices */
2432 		if (test_bit(Faulty, &rdev->flags))
2433 			dprintk("(skipping faulty ");
2434 
2435 		dprintk("%s ", bdevname(rdev->bdev,b));
2436 		if (!test_bit(Faulty, &rdev->flags)) {
2437 			md_super_write(mddev,rdev,
2438 				       rdev->sb_start, rdev->sb_size,
2439 				       rdev->sb_page);
2440 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2441 				bdevname(rdev->bdev,b),
2442 				(unsigned long long)rdev->sb_start);
2443 			rdev->sb_events = mddev->events;
2444 			if (rdev->badblocks.size) {
2445 				md_super_write(mddev, rdev,
2446 					       rdev->badblocks.sector,
2447 					       rdev->badblocks.size << 9,
2448 					       rdev->bb_page);
2449 				rdev->badblocks.size = 0;
2450 			}
2451 
2452 		} else
2453 			dprintk(")\n");
2454 		if (mddev->level == LEVEL_MULTIPATH)
2455 			/* only need to write one superblock... */
2456 			break;
2457 	}
2458 	md_super_wait(mddev);
2459 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2460 
2461 	spin_lock_irq(&mddev->write_lock);
2462 	if (mddev->in_sync != sync_req ||
2463 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2464 		/* have to write it out again */
2465 		spin_unlock_irq(&mddev->write_lock);
2466 		goto repeat;
2467 	}
2468 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2469 	spin_unlock_irq(&mddev->write_lock);
2470 	wake_up(&mddev->sb_wait);
2471 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2472 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2473 
2474 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2475 		if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2476 			clear_bit(Blocked, &rdev->flags);
2477 
2478 		if (any_badblocks_changed)
2479 			md_ack_all_badblocks(&rdev->badblocks);
2480 		clear_bit(BlockedBadBlocks, &rdev->flags);
2481 		wake_up(&rdev->blocked_wait);
2482 	}
2483 }
2484 
2485 /* words written to sysfs files may, or may not, be \n terminated.
2486  * We want to accept with case. For this we use cmd_match.
2487  */
2488 static int cmd_match(const char *cmd, const char *str)
2489 {
2490 	/* See if cmd, written into a sysfs file, matches
2491 	 * str.  They must either be the same, or cmd can
2492 	 * have a trailing newline
2493 	 */
2494 	while (*cmd && *str && *cmd == *str) {
2495 		cmd++;
2496 		str++;
2497 	}
2498 	if (*cmd == '\n')
2499 		cmd++;
2500 	if (*str || *cmd)
2501 		return 0;
2502 	return 1;
2503 }
2504 
2505 struct rdev_sysfs_entry {
2506 	struct attribute attr;
2507 	ssize_t (*show)(mdk_rdev_t *, char *);
2508 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2509 };
2510 
2511 static ssize_t
2512 state_show(mdk_rdev_t *rdev, char *page)
2513 {
2514 	char *sep = "";
2515 	size_t len = 0;
2516 
2517 	if (test_bit(Faulty, &rdev->flags) ||
2518 	    rdev->badblocks.unacked_exist) {
2519 		len+= sprintf(page+len, "%sfaulty",sep);
2520 		sep = ",";
2521 	}
2522 	if (test_bit(In_sync, &rdev->flags)) {
2523 		len += sprintf(page+len, "%sin_sync",sep);
2524 		sep = ",";
2525 	}
2526 	if (test_bit(WriteMostly, &rdev->flags)) {
2527 		len += sprintf(page+len, "%swrite_mostly",sep);
2528 		sep = ",";
2529 	}
2530 	if (test_bit(Blocked, &rdev->flags) ||
2531 	    rdev->badblocks.unacked_exist) {
2532 		len += sprintf(page+len, "%sblocked", sep);
2533 		sep = ",";
2534 	}
2535 	if (!test_bit(Faulty, &rdev->flags) &&
2536 	    !test_bit(In_sync, &rdev->flags)) {
2537 		len += sprintf(page+len, "%sspare", sep);
2538 		sep = ",";
2539 	}
2540 	if (test_bit(WriteErrorSeen, &rdev->flags)) {
2541 		len += sprintf(page+len, "%swrite_error", sep);
2542 		sep = ",";
2543 	}
2544 	return len+sprintf(page+len, "\n");
2545 }
2546 
2547 static ssize_t
2548 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2549 {
2550 	/* can write
2551 	 *  faulty  - simulates an error
2552 	 *  remove  - disconnects the device
2553 	 *  writemostly - sets write_mostly
2554 	 *  -writemostly - clears write_mostly
2555 	 *  blocked - sets the Blocked flags
2556 	 *  -blocked - clears the Blocked and possibly simulates an error
2557 	 *  insync - sets Insync providing device isn't active
2558 	 *  write_error - sets WriteErrorSeen
2559 	 *  -write_error - clears WriteErrorSeen
2560 	 */
2561 	int err = -EINVAL;
2562 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2563 		md_error(rdev->mddev, rdev);
2564 		err = 0;
2565 	} else if (cmd_match(buf, "remove")) {
2566 		if (rdev->raid_disk >= 0)
2567 			err = -EBUSY;
2568 		else {
2569 			mddev_t *mddev = rdev->mddev;
2570 			kick_rdev_from_array(rdev);
2571 			if (mddev->pers)
2572 				md_update_sb(mddev, 1);
2573 			md_new_event(mddev);
2574 			err = 0;
2575 		}
2576 	} else if (cmd_match(buf, "writemostly")) {
2577 		set_bit(WriteMostly, &rdev->flags);
2578 		err = 0;
2579 	} else if (cmd_match(buf, "-writemostly")) {
2580 		clear_bit(WriteMostly, &rdev->flags);
2581 		err = 0;
2582 	} else if (cmd_match(buf, "blocked")) {
2583 		set_bit(Blocked, &rdev->flags);
2584 		err = 0;
2585 	} else if (cmd_match(buf, "-blocked")) {
2586 		if (!test_bit(Faulty, &rdev->flags) &&
2587 		    test_bit(BlockedBadBlocks, &rdev->flags)) {
2588 			/* metadata handler doesn't understand badblocks,
2589 			 * so we need to fail the device
2590 			 */
2591 			md_error(rdev->mddev, rdev);
2592 		}
2593 		clear_bit(Blocked, &rdev->flags);
2594 		clear_bit(BlockedBadBlocks, &rdev->flags);
2595 		wake_up(&rdev->blocked_wait);
2596 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2597 		md_wakeup_thread(rdev->mddev->thread);
2598 
2599 		err = 0;
2600 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2601 		set_bit(In_sync, &rdev->flags);
2602 		err = 0;
2603 	} else if (cmd_match(buf, "write_error")) {
2604 		set_bit(WriteErrorSeen, &rdev->flags);
2605 		err = 0;
2606 	} else if (cmd_match(buf, "-write_error")) {
2607 		clear_bit(WriteErrorSeen, &rdev->flags);
2608 		err = 0;
2609 	}
2610 	if (!err)
2611 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2612 	return err ? err : len;
2613 }
2614 static struct rdev_sysfs_entry rdev_state =
2615 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2616 
2617 static ssize_t
2618 errors_show(mdk_rdev_t *rdev, char *page)
2619 {
2620 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2621 }
2622 
2623 static ssize_t
2624 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2625 {
2626 	char *e;
2627 	unsigned long n = simple_strtoul(buf, &e, 10);
2628 	if (*buf && (*e == 0 || *e == '\n')) {
2629 		atomic_set(&rdev->corrected_errors, n);
2630 		return len;
2631 	}
2632 	return -EINVAL;
2633 }
2634 static struct rdev_sysfs_entry rdev_errors =
2635 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2636 
2637 static ssize_t
2638 slot_show(mdk_rdev_t *rdev, char *page)
2639 {
2640 	if (rdev->raid_disk < 0)
2641 		return sprintf(page, "none\n");
2642 	else
2643 		return sprintf(page, "%d\n", rdev->raid_disk);
2644 }
2645 
2646 static ssize_t
2647 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2648 {
2649 	char *e;
2650 	int err;
2651 	int slot = simple_strtoul(buf, &e, 10);
2652 	if (strncmp(buf, "none", 4)==0)
2653 		slot = -1;
2654 	else if (e==buf || (*e && *e!= '\n'))
2655 		return -EINVAL;
2656 	if (rdev->mddev->pers && slot == -1) {
2657 		/* Setting 'slot' on an active array requires also
2658 		 * updating the 'rd%d' link, and communicating
2659 		 * with the personality with ->hot_*_disk.
2660 		 * For now we only support removing
2661 		 * failed/spare devices.  This normally happens automatically,
2662 		 * but not when the metadata is externally managed.
2663 		 */
2664 		if (rdev->raid_disk == -1)
2665 			return -EEXIST;
2666 		/* personality does all needed checks */
2667 		if (rdev->mddev->pers->hot_remove_disk == NULL)
2668 			return -EINVAL;
2669 		err = rdev->mddev->pers->
2670 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2671 		if (err)
2672 			return err;
2673 		sysfs_unlink_rdev(rdev->mddev, rdev);
2674 		rdev->raid_disk = -1;
2675 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2676 		md_wakeup_thread(rdev->mddev->thread);
2677 	} else if (rdev->mddev->pers) {
2678 		mdk_rdev_t *rdev2;
2679 		/* Activating a spare .. or possibly reactivating
2680 		 * if we ever get bitmaps working here.
2681 		 */
2682 
2683 		if (rdev->raid_disk != -1)
2684 			return -EBUSY;
2685 
2686 		if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2687 			return -EBUSY;
2688 
2689 		if (rdev->mddev->pers->hot_add_disk == NULL)
2690 			return -EINVAL;
2691 
2692 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2693 			if (rdev2->raid_disk == slot)
2694 				return -EEXIST;
2695 
2696 		if (slot >= rdev->mddev->raid_disks &&
2697 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2698 			return -ENOSPC;
2699 
2700 		rdev->raid_disk = slot;
2701 		if (test_bit(In_sync, &rdev->flags))
2702 			rdev->saved_raid_disk = slot;
2703 		else
2704 			rdev->saved_raid_disk = -1;
2705 		err = rdev->mddev->pers->
2706 			hot_add_disk(rdev->mddev, rdev);
2707 		if (err) {
2708 			rdev->raid_disk = -1;
2709 			return err;
2710 		} else
2711 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2712 		if (sysfs_link_rdev(rdev->mddev, rdev))
2713 			/* failure here is OK */;
2714 		/* don't wakeup anyone, leave that to userspace. */
2715 	} else {
2716 		if (slot >= rdev->mddev->raid_disks &&
2717 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2718 			return -ENOSPC;
2719 		rdev->raid_disk = slot;
2720 		/* assume it is working */
2721 		clear_bit(Faulty, &rdev->flags);
2722 		clear_bit(WriteMostly, &rdev->flags);
2723 		set_bit(In_sync, &rdev->flags);
2724 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2725 	}
2726 	return len;
2727 }
2728 
2729 
2730 static struct rdev_sysfs_entry rdev_slot =
2731 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2732 
2733 static ssize_t
2734 offset_show(mdk_rdev_t *rdev, char *page)
2735 {
2736 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2737 }
2738 
2739 static ssize_t
2740 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2741 {
2742 	char *e;
2743 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2744 	if (e==buf || (*e && *e != '\n'))
2745 		return -EINVAL;
2746 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2747 		return -EBUSY;
2748 	if (rdev->sectors && rdev->mddev->external)
2749 		/* Must set offset before size, so overlap checks
2750 		 * can be sane */
2751 		return -EBUSY;
2752 	rdev->data_offset = offset;
2753 	return len;
2754 }
2755 
2756 static struct rdev_sysfs_entry rdev_offset =
2757 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2758 
2759 static ssize_t
2760 rdev_size_show(mdk_rdev_t *rdev, char *page)
2761 {
2762 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2763 }
2764 
2765 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2766 {
2767 	/* check if two start/length pairs overlap */
2768 	if (s1+l1 <= s2)
2769 		return 0;
2770 	if (s2+l2 <= s1)
2771 		return 0;
2772 	return 1;
2773 }
2774 
2775 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2776 {
2777 	unsigned long long blocks;
2778 	sector_t new;
2779 
2780 	if (strict_strtoull(buf, 10, &blocks) < 0)
2781 		return -EINVAL;
2782 
2783 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2784 		return -EINVAL; /* sector conversion overflow */
2785 
2786 	new = blocks * 2;
2787 	if (new != blocks * 2)
2788 		return -EINVAL; /* unsigned long long to sector_t overflow */
2789 
2790 	*sectors = new;
2791 	return 0;
2792 }
2793 
2794 static ssize_t
2795 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2796 {
2797 	mddev_t *my_mddev = rdev->mddev;
2798 	sector_t oldsectors = rdev->sectors;
2799 	sector_t sectors;
2800 
2801 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2802 		return -EINVAL;
2803 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2804 		if (my_mddev->persistent) {
2805 			sectors = super_types[my_mddev->major_version].
2806 				rdev_size_change(rdev, sectors);
2807 			if (!sectors)
2808 				return -EBUSY;
2809 		} else if (!sectors)
2810 			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2811 				rdev->data_offset;
2812 	}
2813 	if (sectors < my_mddev->dev_sectors)
2814 		return -EINVAL; /* component must fit device */
2815 
2816 	rdev->sectors = sectors;
2817 	if (sectors > oldsectors && my_mddev->external) {
2818 		/* need to check that all other rdevs with the same ->bdev
2819 		 * do not overlap.  We need to unlock the mddev to avoid
2820 		 * a deadlock.  We have already changed rdev->sectors, and if
2821 		 * we have to change it back, we will have the lock again.
2822 		 */
2823 		mddev_t *mddev;
2824 		int overlap = 0;
2825 		struct list_head *tmp;
2826 
2827 		mddev_unlock(my_mddev);
2828 		for_each_mddev(mddev, tmp) {
2829 			mdk_rdev_t *rdev2;
2830 
2831 			mddev_lock(mddev);
2832 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2833 				if (rdev->bdev == rdev2->bdev &&
2834 				    rdev != rdev2 &&
2835 				    overlaps(rdev->data_offset, rdev->sectors,
2836 					     rdev2->data_offset,
2837 					     rdev2->sectors)) {
2838 					overlap = 1;
2839 					break;
2840 				}
2841 			mddev_unlock(mddev);
2842 			if (overlap) {
2843 				mddev_put(mddev);
2844 				break;
2845 			}
2846 		}
2847 		mddev_lock(my_mddev);
2848 		if (overlap) {
2849 			/* Someone else could have slipped in a size
2850 			 * change here, but doing so is just silly.
2851 			 * We put oldsectors back because we *know* it is
2852 			 * safe, and trust userspace not to race with
2853 			 * itself
2854 			 */
2855 			rdev->sectors = oldsectors;
2856 			return -EBUSY;
2857 		}
2858 	}
2859 	return len;
2860 }
2861 
2862 static struct rdev_sysfs_entry rdev_size =
2863 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2864 
2865 
2866 static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
2867 {
2868 	unsigned long long recovery_start = rdev->recovery_offset;
2869 
2870 	if (test_bit(In_sync, &rdev->flags) ||
2871 	    recovery_start == MaxSector)
2872 		return sprintf(page, "none\n");
2873 
2874 	return sprintf(page, "%llu\n", recovery_start);
2875 }
2876 
2877 static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2878 {
2879 	unsigned long long recovery_start;
2880 
2881 	if (cmd_match(buf, "none"))
2882 		recovery_start = MaxSector;
2883 	else if (strict_strtoull(buf, 10, &recovery_start))
2884 		return -EINVAL;
2885 
2886 	if (rdev->mddev->pers &&
2887 	    rdev->raid_disk >= 0)
2888 		return -EBUSY;
2889 
2890 	rdev->recovery_offset = recovery_start;
2891 	if (recovery_start == MaxSector)
2892 		set_bit(In_sync, &rdev->flags);
2893 	else
2894 		clear_bit(In_sync, &rdev->flags);
2895 	return len;
2896 }
2897 
2898 static struct rdev_sysfs_entry rdev_recovery_start =
2899 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
2900 
2901 
2902 static ssize_t
2903 badblocks_show(struct badblocks *bb, char *page, int unack);
2904 static ssize_t
2905 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
2906 
2907 static ssize_t bb_show(mdk_rdev_t *rdev, char *page)
2908 {
2909 	return badblocks_show(&rdev->badblocks, page, 0);
2910 }
2911 static ssize_t bb_store(mdk_rdev_t *rdev, const char *page, size_t len)
2912 {
2913 	int rv = badblocks_store(&rdev->badblocks, page, len, 0);
2914 	/* Maybe that ack was all we needed */
2915 	if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
2916 		wake_up(&rdev->blocked_wait);
2917 	return rv;
2918 }
2919 static struct rdev_sysfs_entry rdev_bad_blocks =
2920 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
2921 
2922 
2923 static ssize_t ubb_show(mdk_rdev_t *rdev, char *page)
2924 {
2925 	return badblocks_show(&rdev->badblocks, page, 1);
2926 }
2927 static ssize_t ubb_store(mdk_rdev_t *rdev, const char *page, size_t len)
2928 {
2929 	return badblocks_store(&rdev->badblocks, page, len, 1);
2930 }
2931 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
2932 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
2933 
2934 static struct attribute *rdev_default_attrs[] = {
2935 	&rdev_state.attr,
2936 	&rdev_errors.attr,
2937 	&rdev_slot.attr,
2938 	&rdev_offset.attr,
2939 	&rdev_size.attr,
2940 	&rdev_recovery_start.attr,
2941 	&rdev_bad_blocks.attr,
2942 	&rdev_unack_bad_blocks.attr,
2943 	NULL,
2944 };
2945 static ssize_t
2946 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2947 {
2948 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2949 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2950 	mddev_t *mddev = rdev->mddev;
2951 	ssize_t rv;
2952 
2953 	if (!entry->show)
2954 		return -EIO;
2955 
2956 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2957 	if (!rv) {
2958 		if (rdev->mddev == NULL)
2959 			rv = -EBUSY;
2960 		else
2961 			rv = entry->show(rdev, page);
2962 		mddev_unlock(mddev);
2963 	}
2964 	return rv;
2965 }
2966 
2967 static ssize_t
2968 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2969 	      const char *page, size_t length)
2970 {
2971 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2972 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2973 	ssize_t rv;
2974 	mddev_t *mddev = rdev->mddev;
2975 
2976 	if (!entry->store)
2977 		return -EIO;
2978 	if (!capable(CAP_SYS_ADMIN))
2979 		return -EACCES;
2980 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2981 	if (!rv) {
2982 		if (rdev->mddev == NULL)
2983 			rv = -EBUSY;
2984 		else
2985 			rv = entry->store(rdev, page, length);
2986 		mddev_unlock(mddev);
2987 	}
2988 	return rv;
2989 }
2990 
2991 static void rdev_free(struct kobject *ko)
2992 {
2993 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
2994 	kfree(rdev);
2995 }
2996 static const struct sysfs_ops rdev_sysfs_ops = {
2997 	.show		= rdev_attr_show,
2998 	.store		= rdev_attr_store,
2999 };
3000 static struct kobj_type rdev_ktype = {
3001 	.release	= rdev_free,
3002 	.sysfs_ops	= &rdev_sysfs_ops,
3003 	.default_attrs	= rdev_default_attrs,
3004 };
3005 
3006 int md_rdev_init(mdk_rdev_t *rdev)
3007 {
3008 	rdev->desc_nr = -1;
3009 	rdev->saved_raid_disk = -1;
3010 	rdev->raid_disk = -1;
3011 	rdev->flags = 0;
3012 	rdev->data_offset = 0;
3013 	rdev->sb_events = 0;
3014 	rdev->last_read_error.tv_sec  = 0;
3015 	rdev->last_read_error.tv_nsec = 0;
3016 	rdev->sb_loaded = 0;
3017 	rdev->bb_page = NULL;
3018 	atomic_set(&rdev->nr_pending, 0);
3019 	atomic_set(&rdev->read_errors, 0);
3020 	atomic_set(&rdev->corrected_errors, 0);
3021 
3022 	INIT_LIST_HEAD(&rdev->same_set);
3023 	init_waitqueue_head(&rdev->blocked_wait);
3024 
3025 	/* Add space to store bad block list.
3026 	 * This reserves the space even on arrays where it cannot
3027 	 * be used - I wonder if that matters
3028 	 */
3029 	rdev->badblocks.count = 0;
3030 	rdev->badblocks.shift = 0;
3031 	rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3032 	seqlock_init(&rdev->badblocks.lock);
3033 	if (rdev->badblocks.page == NULL)
3034 		return -ENOMEM;
3035 
3036 	return 0;
3037 }
3038 EXPORT_SYMBOL_GPL(md_rdev_init);
3039 /*
3040  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3041  *
3042  * mark the device faulty if:
3043  *
3044  *   - the device is nonexistent (zero size)
3045  *   - the device has no valid superblock
3046  *
3047  * a faulty rdev _never_ has rdev->sb set.
3048  */
3049 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
3050 {
3051 	char b[BDEVNAME_SIZE];
3052 	int err;
3053 	mdk_rdev_t *rdev;
3054 	sector_t size;
3055 
3056 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3057 	if (!rdev) {
3058 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
3059 		return ERR_PTR(-ENOMEM);
3060 	}
3061 
3062 	err = md_rdev_init(rdev);
3063 	if (err)
3064 		goto abort_free;
3065 	err = alloc_disk_sb(rdev);
3066 	if (err)
3067 		goto abort_free;
3068 
3069 	err = lock_rdev(rdev, newdev, super_format == -2);
3070 	if (err)
3071 		goto abort_free;
3072 
3073 	kobject_init(&rdev->kobj, &rdev_ktype);
3074 
3075 	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3076 	if (!size) {
3077 		printk(KERN_WARNING
3078 			"md: %s has zero or unknown size, marking faulty!\n",
3079 			bdevname(rdev->bdev,b));
3080 		err = -EINVAL;
3081 		goto abort_free;
3082 	}
3083 
3084 	if (super_format >= 0) {
3085 		err = super_types[super_format].
3086 			load_super(rdev, NULL, super_minor);
3087 		if (err == -EINVAL) {
3088 			printk(KERN_WARNING
3089 				"md: %s does not have a valid v%d.%d "
3090 			       "superblock, not importing!\n",
3091 				bdevname(rdev->bdev,b),
3092 			       super_format, super_minor);
3093 			goto abort_free;
3094 		}
3095 		if (err < 0) {
3096 			printk(KERN_WARNING
3097 				"md: could not read %s's sb, not importing!\n",
3098 				bdevname(rdev->bdev,b));
3099 			goto abort_free;
3100 		}
3101 	}
3102 	if (super_format == -1)
3103 		/* hot-add for 0.90, or non-persistent: so no badblocks */
3104 		rdev->badblocks.shift = -1;
3105 
3106 	return rdev;
3107 
3108 abort_free:
3109 	if (rdev->bdev)
3110 		unlock_rdev(rdev);
3111 	free_disk_sb(rdev);
3112 	kfree(rdev->badblocks.page);
3113 	kfree(rdev);
3114 	return ERR_PTR(err);
3115 }
3116 
3117 /*
3118  * Check a full RAID array for plausibility
3119  */
3120 
3121 
3122 static void analyze_sbs(mddev_t * mddev)
3123 {
3124 	int i;
3125 	mdk_rdev_t *rdev, *freshest, *tmp;
3126 	char b[BDEVNAME_SIZE];
3127 
3128 	freshest = NULL;
3129 	rdev_for_each(rdev, tmp, mddev)
3130 		switch (super_types[mddev->major_version].
3131 			load_super(rdev, freshest, mddev->minor_version)) {
3132 		case 1:
3133 			freshest = rdev;
3134 			break;
3135 		case 0:
3136 			break;
3137 		default:
3138 			printk( KERN_ERR \
3139 				"md: fatal superblock inconsistency in %s"
3140 				" -- removing from array\n",
3141 				bdevname(rdev->bdev,b));
3142 			kick_rdev_from_array(rdev);
3143 		}
3144 
3145 
3146 	super_types[mddev->major_version].
3147 		validate_super(mddev, freshest);
3148 
3149 	i = 0;
3150 	rdev_for_each(rdev, tmp, mddev) {
3151 		if (mddev->max_disks &&
3152 		    (rdev->desc_nr >= mddev->max_disks ||
3153 		     i > mddev->max_disks)) {
3154 			printk(KERN_WARNING
3155 			       "md: %s: %s: only %d devices permitted\n",
3156 			       mdname(mddev), bdevname(rdev->bdev, b),
3157 			       mddev->max_disks);
3158 			kick_rdev_from_array(rdev);
3159 			continue;
3160 		}
3161 		if (rdev != freshest)
3162 			if (super_types[mddev->major_version].
3163 			    validate_super(mddev, rdev)) {
3164 				printk(KERN_WARNING "md: kicking non-fresh %s"
3165 					" from array!\n",
3166 					bdevname(rdev->bdev,b));
3167 				kick_rdev_from_array(rdev);
3168 				continue;
3169 			}
3170 		if (mddev->level == LEVEL_MULTIPATH) {
3171 			rdev->desc_nr = i++;
3172 			rdev->raid_disk = rdev->desc_nr;
3173 			set_bit(In_sync, &rdev->flags);
3174 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3175 			rdev->raid_disk = -1;
3176 			clear_bit(In_sync, &rdev->flags);
3177 		}
3178 	}
3179 }
3180 
3181 /* Read a fixed-point number.
3182  * Numbers in sysfs attributes should be in "standard" units where
3183  * possible, so time should be in seconds.
3184  * However we internally use a a much smaller unit such as
3185  * milliseconds or jiffies.
3186  * This function takes a decimal number with a possible fractional
3187  * component, and produces an integer which is the result of
3188  * multiplying that number by 10^'scale'.
3189  * all without any floating-point arithmetic.
3190  */
3191 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3192 {
3193 	unsigned long result = 0;
3194 	long decimals = -1;
3195 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3196 		if (*cp == '.')
3197 			decimals = 0;
3198 		else if (decimals < scale) {
3199 			unsigned int value;
3200 			value = *cp - '0';
3201 			result = result * 10 + value;
3202 			if (decimals >= 0)
3203 				decimals++;
3204 		}
3205 		cp++;
3206 	}
3207 	if (*cp == '\n')
3208 		cp++;
3209 	if (*cp)
3210 		return -EINVAL;
3211 	if (decimals < 0)
3212 		decimals = 0;
3213 	while (decimals < scale) {
3214 		result *= 10;
3215 		decimals ++;
3216 	}
3217 	*res = result;
3218 	return 0;
3219 }
3220 
3221 
3222 static void md_safemode_timeout(unsigned long data);
3223 
3224 static ssize_t
3225 safe_delay_show(mddev_t *mddev, char *page)
3226 {
3227 	int msec = (mddev->safemode_delay*1000)/HZ;
3228 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3229 }
3230 static ssize_t
3231 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
3232 {
3233 	unsigned long msec;
3234 
3235 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3236 		return -EINVAL;
3237 	if (msec == 0)
3238 		mddev->safemode_delay = 0;
3239 	else {
3240 		unsigned long old_delay = mddev->safemode_delay;
3241 		mddev->safemode_delay = (msec*HZ)/1000;
3242 		if (mddev->safemode_delay == 0)
3243 			mddev->safemode_delay = 1;
3244 		if (mddev->safemode_delay < old_delay)
3245 			md_safemode_timeout((unsigned long)mddev);
3246 	}
3247 	return len;
3248 }
3249 static struct md_sysfs_entry md_safe_delay =
3250 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3251 
3252 static ssize_t
3253 level_show(mddev_t *mddev, char *page)
3254 {
3255 	struct mdk_personality *p = mddev->pers;
3256 	if (p)
3257 		return sprintf(page, "%s\n", p->name);
3258 	else if (mddev->clevel[0])
3259 		return sprintf(page, "%s\n", mddev->clevel);
3260 	else if (mddev->level != LEVEL_NONE)
3261 		return sprintf(page, "%d\n", mddev->level);
3262 	else
3263 		return 0;
3264 }
3265 
3266 static ssize_t
3267 level_store(mddev_t *mddev, const char *buf, size_t len)
3268 {
3269 	char clevel[16];
3270 	ssize_t rv = len;
3271 	struct mdk_personality *pers;
3272 	long level;
3273 	void *priv;
3274 	mdk_rdev_t *rdev;
3275 
3276 	if (mddev->pers == NULL) {
3277 		if (len == 0)
3278 			return 0;
3279 		if (len >= sizeof(mddev->clevel))
3280 			return -ENOSPC;
3281 		strncpy(mddev->clevel, buf, len);
3282 		if (mddev->clevel[len-1] == '\n')
3283 			len--;
3284 		mddev->clevel[len] = 0;
3285 		mddev->level = LEVEL_NONE;
3286 		return rv;
3287 	}
3288 
3289 	/* request to change the personality.  Need to ensure:
3290 	 *  - array is not engaged in resync/recovery/reshape
3291 	 *  - old personality can be suspended
3292 	 *  - new personality will access other array.
3293 	 */
3294 
3295 	if (mddev->sync_thread ||
3296 	    mddev->reshape_position != MaxSector ||
3297 	    mddev->sysfs_active)
3298 		return -EBUSY;
3299 
3300 	if (!mddev->pers->quiesce) {
3301 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3302 		       mdname(mddev), mddev->pers->name);
3303 		return -EINVAL;
3304 	}
3305 
3306 	/* Now find the new personality */
3307 	if (len == 0 || len >= sizeof(clevel))
3308 		return -EINVAL;
3309 	strncpy(clevel, buf, len);
3310 	if (clevel[len-1] == '\n')
3311 		len--;
3312 	clevel[len] = 0;
3313 	if (strict_strtol(clevel, 10, &level))
3314 		level = LEVEL_NONE;
3315 
3316 	if (request_module("md-%s", clevel) != 0)
3317 		request_module("md-level-%s", clevel);
3318 	spin_lock(&pers_lock);
3319 	pers = find_pers(level, clevel);
3320 	if (!pers || !try_module_get(pers->owner)) {
3321 		spin_unlock(&pers_lock);
3322 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3323 		return -EINVAL;
3324 	}
3325 	spin_unlock(&pers_lock);
3326 
3327 	if (pers == mddev->pers) {
3328 		/* Nothing to do! */
3329 		module_put(pers->owner);
3330 		return rv;
3331 	}
3332 	if (!pers->takeover) {
3333 		module_put(pers->owner);
3334 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3335 		       mdname(mddev), clevel);
3336 		return -EINVAL;
3337 	}
3338 
3339 	list_for_each_entry(rdev, &mddev->disks, same_set)
3340 		rdev->new_raid_disk = rdev->raid_disk;
3341 
3342 	/* ->takeover must set new_* and/or delta_disks
3343 	 * if it succeeds, and may set them when it fails.
3344 	 */
3345 	priv = pers->takeover(mddev);
3346 	if (IS_ERR(priv)) {
3347 		mddev->new_level = mddev->level;
3348 		mddev->new_layout = mddev->layout;
3349 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3350 		mddev->raid_disks -= mddev->delta_disks;
3351 		mddev->delta_disks = 0;
3352 		module_put(pers->owner);
3353 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3354 		       mdname(mddev), clevel);
3355 		return PTR_ERR(priv);
3356 	}
3357 
3358 	/* Looks like we have a winner */
3359 	mddev_suspend(mddev);
3360 	mddev->pers->stop(mddev);
3361 
3362 	if (mddev->pers->sync_request == NULL &&
3363 	    pers->sync_request != NULL) {
3364 		/* need to add the md_redundancy_group */
3365 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3366 			printk(KERN_WARNING
3367 			       "md: cannot register extra attributes for %s\n",
3368 			       mdname(mddev));
3369 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3370 	}
3371 	if (mddev->pers->sync_request != NULL &&
3372 	    pers->sync_request == NULL) {
3373 		/* need to remove the md_redundancy_group */
3374 		if (mddev->to_remove == NULL)
3375 			mddev->to_remove = &md_redundancy_group;
3376 	}
3377 
3378 	if (mddev->pers->sync_request == NULL &&
3379 	    mddev->external) {
3380 		/* We are converting from a no-redundancy array
3381 		 * to a redundancy array and metadata is managed
3382 		 * externally so we need to be sure that writes
3383 		 * won't block due to a need to transition
3384 		 *      clean->dirty
3385 		 * until external management is started.
3386 		 */
3387 		mddev->in_sync = 0;
3388 		mddev->safemode_delay = 0;
3389 		mddev->safemode = 0;
3390 	}
3391 
3392 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3393 		if (rdev->raid_disk < 0)
3394 			continue;
3395 		if (rdev->new_raid_disk >= mddev->raid_disks)
3396 			rdev->new_raid_disk = -1;
3397 		if (rdev->new_raid_disk == rdev->raid_disk)
3398 			continue;
3399 		sysfs_unlink_rdev(mddev, rdev);
3400 	}
3401 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3402 		if (rdev->raid_disk < 0)
3403 			continue;
3404 		if (rdev->new_raid_disk == rdev->raid_disk)
3405 			continue;
3406 		rdev->raid_disk = rdev->new_raid_disk;
3407 		if (rdev->raid_disk < 0)
3408 			clear_bit(In_sync, &rdev->flags);
3409 		else {
3410 			if (sysfs_link_rdev(mddev, rdev))
3411 				printk(KERN_WARNING "md: cannot register rd%d"
3412 				       " for %s after level change\n",
3413 				       rdev->raid_disk, mdname(mddev));
3414 		}
3415 	}
3416 
3417 	module_put(mddev->pers->owner);
3418 	mddev->pers = pers;
3419 	mddev->private = priv;
3420 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3421 	mddev->level = mddev->new_level;
3422 	mddev->layout = mddev->new_layout;
3423 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3424 	mddev->delta_disks = 0;
3425 	mddev->degraded = 0;
3426 	if (mddev->pers->sync_request == NULL) {
3427 		/* this is now an array without redundancy, so
3428 		 * it must always be in_sync
3429 		 */
3430 		mddev->in_sync = 1;
3431 		del_timer_sync(&mddev->safemode_timer);
3432 	}
3433 	pers->run(mddev);
3434 	mddev_resume(mddev);
3435 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3436 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3437 	md_wakeup_thread(mddev->thread);
3438 	sysfs_notify(&mddev->kobj, NULL, "level");
3439 	md_new_event(mddev);
3440 	return rv;
3441 }
3442 
3443 static struct md_sysfs_entry md_level =
3444 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3445 
3446 
3447 static ssize_t
3448 layout_show(mddev_t *mddev, char *page)
3449 {
3450 	/* just a number, not meaningful for all levels */
3451 	if (mddev->reshape_position != MaxSector &&
3452 	    mddev->layout != mddev->new_layout)
3453 		return sprintf(page, "%d (%d)\n",
3454 			       mddev->new_layout, mddev->layout);
3455 	return sprintf(page, "%d\n", mddev->layout);
3456 }
3457 
3458 static ssize_t
3459 layout_store(mddev_t *mddev, const char *buf, size_t len)
3460 {
3461 	char *e;
3462 	unsigned long n = simple_strtoul(buf, &e, 10);
3463 
3464 	if (!*buf || (*e && *e != '\n'))
3465 		return -EINVAL;
3466 
3467 	if (mddev->pers) {
3468 		int err;
3469 		if (mddev->pers->check_reshape == NULL)
3470 			return -EBUSY;
3471 		mddev->new_layout = n;
3472 		err = mddev->pers->check_reshape(mddev);
3473 		if (err) {
3474 			mddev->new_layout = mddev->layout;
3475 			return err;
3476 		}
3477 	} else {
3478 		mddev->new_layout = n;
3479 		if (mddev->reshape_position == MaxSector)
3480 			mddev->layout = n;
3481 	}
3482 	return len;
3483 }
3484 static struct md_sysfs_entry md_layout =
3485 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3486 
3487 
3488 static ssize_t
3489 raid_disks_show(mddev_t *mddev, char *page)
3490 {
3491 	if (mddev->raid_disks == 0)
3492 		return 0;
3493 	if (mddev->reshape_position != MaxSector &&
3494 	    mddev->delta_disks != 0)
3495 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3496 			       mddev->raid_disks - mddev->delta_disks);
3497 	return sprintf(page, "%d\n", mddev->raid_disks);
3498 }
3499 
3500 static int update_raid_disks(mddev_t *mddev, int raid_disks);
3501 
3502 static ssize_t
3503 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
3504 {
3505 	char *e;
3506 	int rv = 0;
3507 	unsigned long n = simple_strtoul(buf, &e, 10);
3508 
3509 	if (!*buf || (*e && *e != '\n'))
3510 		return -EINVAL;
3511 
3512 	if (mddev->pers)
3513 		rv = update_raid_disks(mddev, n);
3514 	else if (mddev->reshape_position != MaxSector) {
3515 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3516 		mddev->delta_disks = n - olddisks;
3517 		mddev->raid_disks = n;
3518 	} else
3519 		mddev->raid_disks = n;
3520 	return rv ? rv : len;
3521 }
3522 static struct md_sysfs_entry md_raid_disks =
3523 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3524 
3525 static ssize_t
3526 chunk_size_show(mddev_t *mddev, char *page)
3527 {
3528 	if (mddev->reshape_position != MaxSector &&
3529 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3530 		return sprintf(page, "%d (%d)\n",
3531 			       mddev->new_chunk_sectors << 9,
3532 			       mddev->chunk_sectors << 9);
3533 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3534 }
3535 
3536 static ssize_t
3537 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
3538 {
3539 	char *e;
3540 	unsigned long n = simple_strtoul(buf, &e, 10);
3541 
3542 	if (!*buf || (*e && *e != '\n'))
3543 		return -EINVAL;
3544 
3545 	if (mddev->pers) {
3546 		int err;
3547 		if (mddev->pers->check_reshape == NULL)
3548 			return -EBUSY;
3549 		mddev->new_chunk_sectors = n >> 9;
3550 		err = mddev->pers->check_reshape(mddev);
3551 		if (err) {
3552 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3553 			return err;
3554 		}
3555 	} else {
3556 		mddev->new_chunk_sectors = n >> 9;
3557 		if (mddev->reshape_position == MaxSector)
3558 			mddev->chunk_sectors = n >> 9;
3559 	}
3560 	return len;
3561 }
3562 static struct md_sysfs_entry md_chunk_size =
3563 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3564 
3565 static ssize_t
3566 resync_start_show(mddev_t *mddev, char *page)
3567 {
3568 	if (mddev->recovery_cp == MaxSector)
3569 		return sprintf(page, "none\n");
3570 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3571 }
3572 
3573 static ssize_t
3574 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
3575 {
3576 	char *e;
3577 	unsigned long long n = simple_strtoull(buf, &e, 10);
3578 
3579 	if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3580 		return -EBUSY;
3581 	if (cmd_match(buf, "none"))
3582 		n = MaxSector;
3583 	else if (!*buf || (*e && *e != '\n'))
3584 		return -EINVAL;
3585 
3586 	mddev->recovery_cp = n;
3587 	return len;
3588 }
3589 static struct md_sysfs_entry md_resync_start =
3590 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3591 
3592 /*
3593  * The array state can be:
3594  *
3595  * clear
3596  *     No devices, no size, no level
3597  *     Equivalent to STOP_ARRAY ioctl
3598  * inactive
3599  *     May have some settings, but array is not active
3600  *        all IO results in error
3601  *     When written, doesn't tear down array, but just stops it
3602  * suspended (not supported yet)
3603  *     All IO requests will block. The array can be reconfigured.
3604  *     Writing this, if accepted, will block until array is quiescent
3605  * readonly
3606  *     no resync can happen.  no superblocks get written.
3607  *     write requests fail
3608  * read-auto
3609  *     like readonly, but behaves like 'clean' on a write request.
3610  *
3611  * clean - no pending writes, but otherwise active.
3612  *     When written to inactive array, starts without resync
3613  *     If a write request arrives then
3614  *       if metadata is known, mark 'dirty' and switch to 'active'.
3615  *       if not known, block and switch to write-pending
3616  *     If written to an active array that has pending writes, then fails.
3617  * active
3618  *     fully active: IO and resync can be happening.
3619  *     When written to inactive array, starts with resync
3620  *
3621  * write-pending
3622  *     clean, but writes are blocked waiting for 'active' to be written.
3623  *
3624  * active-idle
3625  *     like active, but no writes have been seen for a while (100msec).
3626  *
3627  */
3628 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3629 		   write_pending, active_idle, bad_word};
3630 static char *array_states[] = {
3631 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3632 	"write-pending", "active-idle", NULL };
3633 
3634 static int match_word(const char *word, char **list)
3635 {
3636 	int n;
3637 	for (n=0; list[n]; n++)
3638 		if (cmd_match(word, list[n]))
3639 			break;
3640 	return n;
3641 }
3642 
3643 static ssize_t
3644 array_state_show(mddev_t *mddev, char *page)
3645 {
3646 	enum array_state st = inactive;
3647 
3648 	if (mddev->pers)
3649 		switch(mddev->ro) {
3650 		case 1:
3651 			st = readonly;
3652 			break;
3653 		case 2:
3654 			st = read_auto;
3655 			break;
3656 		case 0:
3657 			if (mddev->in_sync)
3658 				st = clean;
3659 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3660 				st = write_pending;
3661 			else if (mddev->safemode)
3662 				st = active_idle;
3663 			else
3664 				st = active;
3665 		}
3666 	else {
3667 		if (list_empty(&mddev->disks) &&
3668 		    mddev->raid_disks == 0 &&
3669 		    mddev->dev_sectors == 0)
3670 			st = clear;
3671 		else
3672 			st = inactive;
3673 	}
3674 	return sprintf(page, "%s\n", array_states[st]);
3675 }
3676 
3677 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3678 static int md_set_readonly(mddev_t * mddev, int is_open);
3679 static int do_md_run(mddev_t * mddev);
3680 static int restart_array(mddev_t *mddev);
3681 
3682 static ssize_t
3683 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3684 {
3685 	int err = -EINVAL;
3686 	enum array_state st = match_word(buf, array_states);
3687 	switch(st) {
3688 	case bad_word:
3689 		break;
3690 	case clear:
3691 		/* stopping an active array */
3692 		if (atomic_read(&mddev->openers) > 0)
3693 			return -EBUSY;
3694 		err = do_md_stop(mddev, 0, 0);
3695 		break;
3696 	case inactive:
3697 		/* stopping an active array */
3698 		if (mddev->pers) {
3699 			if (atomic_read(&mddev->openers) > 0)
3700 				return -EBUSY;
3701 			err = do_md_stop(mddev, 2, 0);
3702 		} else
3703 			err = 0; /* already inactive */
3704 		break;
3705 	case suspended:
3706 		break; /* not supported yet */
3707 	case readonly:
3708 		if (mddev->pers)
3709 			err = md_set_readonly(mddev, 0);
3710 		else {
3711 			mddev->ro = 1;
3712 			set_disk_ro(mddev->gendisk, 1);
3713 			err = do_md_run(mddev);
3714 		}
3715 		break;
3716 	case read_auto:
3717 		if (mddev->pers) {
3718 			if (mddev->ro == 0)
3719 				err = md_set_readonly(mddev, 0);
3720 			else if (mddev->ro == 1)
3721 				err = restart_array(mddev);
3722 			if (err == 0) {
3723 				mddev->ro = 2;
3724 				set_disk_ro(mddev->gendisk, 0);
3725 			}
3726 		} else {
3727 			mddev->ro = 2;
3728 			err = do_md_run(mddev);
3729 		}
3730 		break;
3731 	case clean:
3732 		if (mddev->pers) {
3733 			restart_array(mddev);
3734 			spin_lock_irq(&mddev->write_lock);
3735 			if (atomic_read(&mddev->writes_pending) == 0) {
3736 				if (mddev->in_sync == 0) {
3737 					mddev->in_sync = 1;
3738 					if (mddev->safemode == 1)
3739 						mddev->safemode = 0;
3740 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3741 				}
3742 				err = 0;
3743 			} else
3744 				err = -EBUSY;
3745 			spin_unlock_irq(&mddev->write_lock);
3746 		} else
3747 			err = -EINVAL;
3748 		break;
3749 	case active:
3750 		if (mddev->pers) {
3751 			restart_array(mddev);
3752 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3753 			wake_up(&mddev->sb_wait);
3754 			err = 0;
3755 		} else {
3756 			mddev->ro = 0;
3757 			set_disk_ro(mddev->gendisk, 0);
3758 			err = do_md_run(mddev);
3759 		}
3760 		break;
3761 	case write_pending:
3762 	case active_idle:
3763 		/* these cannot be set */
3764 		break;
3765 	}
3766 	if (err)
3767 		return err;
3768 	else {
3769 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3770 		return len;
3771 	}
3772 }
3773 static struct md_sysfs_entry md_array_state =
3774 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3775 
3776 static ssize_t
3777 max_corrected_read_errors_show(mddev_t *mddev, char *page) {
3778 	return sprintf(page, "%d\n",
3779 		       atomic_read(&mddev->max_corr_read_errors));
3780 }
3781 
3782 static ssize_t
3783 max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
3784 {
3785 	char *e;
3786 	unsigned long n = simple_strtoul(buf, &e, 10);
3787 
3788 	if (*buf && (*e == 0 || *e == '\n')) {
3789 		atomic_set(&mddev->max_corr_read_errors, n);
3790 		return len;
3791 	}
3792 	return -EINVAL;
3793 }
3794 
3795 static struct md_sysfs_entry max_corr_read_errors =
3796 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3797 	max_corrected_read_errors_store);
3798 
3799 static ssize_t
3800 null_show(mddev_t *mddev, char *page)
3801 {
3802 	return -EINVAL;
3803 }
3804 
3805 static ssize_t
3806 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3807 {
3808 	/* buf must be %d:%d\n? giving major and minor numbers */
3809 	/* The new device is added to the array.
3810 	 * If the array has a persistent superblock, we read the
3811 	 * superblock to initialise info and check validity.
3812 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3813 	 * which mainly checks size.
3814 	 */
3815 	char *e;
3816 	int major = simple_strtoul(buf, &e, 10);
3817 	int minor;
3818 	dev_t dev;
3819 	mdk_rdev_t *rdev;
3820 	int err;
3821 
3822 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3823 		return -EINVAL;
3824 	minor = simple_strtoul(e+1, &e, 10);
3825 	if (*e && *e != '\n')
3826 		return -EINVAL;
3827 	dev = MKDEV(major, minor);
3828 	if (major != MAJOR(dev) ||
3829 	    minor != MINOR(dev))
3830 		return -EOVERFLOW;
3831 
3832 
3833 	if (mddev->persistent) {
3834 		rdev = md_import_device(dev, mddev->major_version,
3835 					mddev->minor_version);
3836 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3837 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3838 						       mdk_rdev_t, same_set);
3839 			err = super_types[mddev->major_version]
3840 				.load_super(rdev, rdev0, mddev->minor_version);
3841 			if (err < 0)
3842 				goto out;
3843 		}
3844 	} else if (mddev->external)
3845 		rdev = md_import_device(dev, -2, -1);
3846 	else
3847 		rdev = md_import_device(dev, -1, -1);
3848 
3849 	if (IS_ERR(rdev))
3850 		return PTR_ERR(rdev);
3851 	err = bind_rdev_to_array(rdev, mddev);
3852  out:
3853 	if (err)
3854 		export_rdev(rdev);
3855 	return err ? err : len;
3856 }
3857 
3858 static struct md_sysfs_entry md_new_device =
3859 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3860 
3861 static ssize_t
3862 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3863 {
3864 	char *end;
3865 	unsigned long chunk, end_chunk;
3866 
3867 	if (!mddev->bitmap)
3868 		goto out;
3869 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3870 	while (*buf) {
3871 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3872 		if (buf == end) break;
3873 		if (*end == '-') { /* range */
3874 			buf = end + 1;
3875 			end_chunk = simple_strtoul(buf, &end, 0);
3876 			if (buf == end) break;
3877 		}
3878 		if (*end && !isspace(*end)) break;
3879 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3880 		buf = skip_spaces(end);
3881 	}
3882 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3883 out:
3884 	return len;
3885 }
3886 
3887 static struct md_sysfs_entry md_bitmap =
3888 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3889 
3890 static ssize_t
3891 size_show(mddev_t *mddev, char *page)
3892 {
3893 	return sprintf(page, "%llu\n",
3894 		(unsigned long long)mddev->dev_sectors / 2);
3895 }
3896 
3897 static int update_size(mddev_t *mddev, sector_t num_sectors);
3898 
3899 static ssize_t
3900 size_store(mddev_t *mddev, const char *buf, size_t len)
3901 {
3902 	/* If array is inactive, we can reduce the component size, but
3903 	 * not increase it (except from 0).
3904 	 * If array is active, we can try an on-line resize
3905 	 */
3906 	sector_t sectors;
3907 	int err = strict_blocks_to_sectors(buf, &sectors);
3908 
3909 	if (err < 0)
3910 		return err;
3911 	if (mddev->pers) {
3912 		err = update_size(mddev, sectors);
3913 		md_update_sb(mddev, 1);
3914 	} else {
3915 		if (mddev->dev_sectors == 0 ||
3916 		    mddev->dev_sectors > sectors)
3917 			mddev->dev_sectors = sectors;
3918 		else
3919 			err = -ENOSPC;
3920 	}
3921 	return err ? err : len;
3922 }
3923 
3924 static struct md_sysfs_entry md_size =
3925 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3926 
3927 
3928 /* Metdata version.
3929  * This is one of
3930  *   'none' for arrays with no metadata (good luck...)
3931  *   'external' for arrays with externally managed metadata,
3932  * or N.M for internally known formats
3933  */
3934 static ssize_t
3935 metadata_show(mddev_t *mddev, char *page)
3936 {
3937 	if (mddev->persistent)
3938 		return sprintf(page, "%d.%d\n",
3939 			       mddev->major_version, mddev->minor_version);
3940 	else if (mddev->external)
3941 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3942 	else
3943 		return sprintf(page, "none\n");
3944 }
3945 
3946 static ssize_t
3947 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3948 {
3949 	int major, minor;
3950 	char *e;
3951 	/* Changing the details of 'external' metadata is
3952 	 * always permitted.  Otherwise there must be
3953 	 * no devices attached to the array.
3954 	 */
3955 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3956 		;
3957 	else if (!list_empty(&mddev->disks))
3958 		return -EBUSY;
3959 
3960 	if (cmd_match(buf, "none")) {
3961 		mddev->persistent = 0;
3962 		mddev->external = 0;
3963 		mddev->major_version = 0;
3964 		mddev->minor_version = 90;
3965 		return len;
3966 	}
3967 	if (strncmp(buf, "external:", 9) == 0) {
3968 		size_t namelen = len-9;
3969 		if (namelen >= sizeof(mddev->metadata_type))
3970 			namelen = sizeof(mddev->metadata_type)-1;
3971 		strncpy(mddev->metadata_type, buf+9, namelen);
3972 		mddev->metadata_type[namelen] = 0;
3973 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3974 			mddev->metadata_type[--namelen] = 0;
3975 		mddev->persistent = 0;
3976 		mddev->external = 1;
3977 		mddev->major_version = 0;
3978 		mddev->minor_version = 90;
3979 		return len;
3980 	}
3981 	major = simple_strtoul(buf, &e, 10);
3982 	if (e==buf || *e != '.')
3983 		return -EINVAL;
3984 	buf = e+1;
3985 	minor = simple_strtoul(buf, &e, 10);
3986 	if (e==buf || (*e && *e != '\n') )
3987 		return -EINVAL;
3988 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
3989 		return -ENOENT;
3990 	mddev->major_version = major;
3991 	mddev->minor_version = minor;
3992 	mddev->persistent = 1;
3993 	mddev->external = 0;
3994 	return len;
3995 }
3996 
3997 static struct md_sysfs_entry md_metadata =
3998 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
3999 
4000 static ssize_t
4001 action_show(mddev_t *mddev, char *page)
4002 {
4003 	char *type = "idle";
4004 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4005 		type = "frozen";
4006 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4007 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4008 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4009 			type = "reshape";
4010 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4011 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4012 				type = "resync";
4013 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4014 				type = "check";
4015 			else
4016 				type = "repair";
4017 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4018 			type = "recover";
4019 	}
4020 	return sprintf(page, "%s\n", type);
4021 }
4022 
4023 static void reap_sync_thread(mddev_t *mddev);
4024 
4025 static ssize_t
4026 action_store(mddev_t *mddev, const char *page, size_t len)
4027 {
4028 	if (!mddev->pers || !mddev->pers->sync_request)
4029 		return -EINVAL;
4030 
4031 	if (cmd_match(page, "frozen"))
4032 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4033 	else
4034 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4035 
4036 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4037 		if (mddev->sync_thread) {
4038 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4039 			reap_sync_thread(mddev);
4040 		}
4041 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4042 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4043 		return -EBUSY;
4044 	else if (cmd_match(page, "resync"))
4045 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4046 	else if (cmd_match(page, "recover")) {
4047 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4048 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4049 	} else if (cmd_match(page, "reshape")) {
4050 		int err;
4051 		if (mddev->pers->start_reshape == NULL)
4052 			return -EINVAL;
4053 		err = mddev->pers->start_reshape(mddev);
4054 		if (err)
4055 			return err;
4056 		sysfs_notify(&mddev->kobj, NULL, "degraded");
4057 	} else {
4058 		if (cmd_match(page, "check"))
4059 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4060 		else if (!cmd_match(page, "repair"))
4061 			return -EINVAL;
4062 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4063 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4064 	}
4065 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4066 	md_wakeup_thread(mddev->thread);
4067 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4068 	return len;
4069 }
4070 
4071 static ssize_t
4072 mismatch_cnt_show(mddev_t *mddev, char *page)
4073 {
4074 	return sprintf(page, "%llu\n",
4075 		       (unsigned long long) mddev->resync_mismatches);
4076 }
4077 
4078 static struct md_sysfs_entry md_scan_mode =
4079 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4080 
4081 
4082 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4083 
4084 static ssize_t
4085 sync_min_show(mddev_t *mddev, char *page)
4086 {
4087 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
4088 		       mddev->sync_speed_min ? "local": "system");
4089 }
4090 
4091 static ssize_t
4092 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
4093 {
4094 	int min;
4095 	char *e;
4096 	if (strncmp(buf, "system", 6)==0) {
4097 		mddev->sync_speed_min = 0;
4098 		return len;
4099 	}
4100 	min = simple_strtoul(buf, &e, 10);
4101 	if (buf == e || (*e && *e != '\n') || min <= 0)
4102 		return -EINVAL;
4103 	mddev->sync_speed_min = min;
4104 	return len;
4105 }
4106 
4107 static struct md_sysfs_entry md_sync_min =
4108 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4109 
4110 static ssize_t
4111 sync_max_show(mddev_t *mddev, char *page)
4112 {
4113 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
4114 		       mddev->sync_speed_max ? "local": "system");
4115 }
4116 
4117 static ssize_t
4118 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
4119 {
4120 	int max;
4121 	char *e;
4122 	if (strncmp(buf, "system", 6)==0) {
4123 		mddev->sync_speed_max = 0;
4124 		return len;
4125 	}
4126 	max = simple_strtoul(buf, &e, 10);
4127 	if (buf == e || (*e && *e != '\n') || max <= 0)
4128 		return -EINVAL;
4129 	mddev->sync_speed_max = max;
4130 	return len;
4131 }
4132 
4133 static struct md_sysfs_entry md_sync_max =
4134 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4135 
4136 static ssize_t
4137 degraded_show(mddev_t *mddev, char *page)
4138 {
4139 	return sprintf(page, "%d\n", mddev->degraded);
4140 }
4141 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4142 
4143 static ssize_t
4144 sync_force_parallel_show(mddev_t *mddev, char *page)
4145 {
4146 	return sprintf(page, "%d\n", mddev->parallel_resync);
4147 }
4148 
4149 static ssize_t
4150 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
4151 {
4152 	long n;
4153 
4154 	if (strict_strtol(buf, 10, &n))
4155 		return -EINVAL;
4156 
4157 	if (n != 0 && n != 1)
4158 		return -EINVAL;
4159 
4160 	mddev->parallel_resync = n;
4161 
4162 	if (mddev->sync_thread)
4163 		wake_up(&resync_wait);
4164 
4165 	return len;
4166 }
4167 
4168 /* force parallel resync, even with shared block devices */
4169 static struct md_sysfs_entry md_sync_force_parallel =
4170 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4171        sync_force_parallel_show, sync_force_parallel_store);
4172 
4173 static ssize_t
4174 sync_speed_show(mddev_t *mddev, char *page)
4175 {
4176 	unsigned long resync, dt, db;
4177 	if (mddev->curr_resync == 0)
4178 		return sprintf(page, "none\n");
4179 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4180 	dt = (jiffies - mddev->resync_mark) / HZ;
4181 	if (!dt) dt++;
4182 	db = resync - mddev->resync_mark_cnt;
4183 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4184 }
4185 
4186 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4187 
4188 static ssize_t
4189 sync_completed_show(mddev_t *mddev, char *page)
4190 {
4191 	unsigned long long max_sectors, resync;
4192 
4193 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4194 		return sprintf(page, "none\n");
4195 
4196 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4197 		max_sectors = mddev->resync_max_sectors;
4198 	else
4199 		max_sectors = mddev->dev_sectors;
4200 
4201 	resync = mddev->curr_resync_completed;
4202 	return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4203 }
4204 
4205 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4206 
4207 static ssize_t
4208 min_sync_show(mddev_t *mddev, char *page)
4209 {
4210 	return sprintf(page, "%llu\n",
4211 		       (unsigned long long)mddev->resync_min);
4212 }
4213 static ssize_t
4214 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
4215 {
4216 	unsigned long long min;
4217 	if (strict_strtoull(buf, 10, &min))
4218 		return -EINVAL;
4219 	if (min > mddev->resync_max)
4220 		return -EINVAL;
4221 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4222 		return -EBUSY;
4223 
4224 	/* Must be a multiple of chunk_size */
4225 	if (mddev->chunk_sectors) {
4226 		sector_t temp = min;
4227 		if (sector_div(temp, mddev->chunk_sectors))
4228 			return -EINVAL;
4229 	}
4230 	mddev->resync_min = min;
4231 
4232 	return len;
4233 }
4234 
4235 static struct md_sysfs_entry md_min_sync =
4236 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4237 
4238 static ssize_t
4239 max_sync_show(mddev_t *mddev, char *page)
4240 {
4241 	if (mddev->resync_max == MaxSector)
4242 		return sprintf(page, "max\n");
4243 	else
4244 		return sprintf(page, "%llu\n",
4245 			       (unsigned long long)mddev->resync_max);
4246 }
4247 static ssize_t
4248 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
4249 {
4250 	if (strncmp(buf, "max", 3) == 0)
4251 		mddev->resync_max = MaxSector;
4252 	else {
4253 		unsigned long long max;
4254 		if (strict_strtoull(buf, 10, &max))
4255 			return -EINVAL;
4256 		if (max < mddev->resync_min)
4257 			return -EINVAL;
4258 		if (max < mddev->resync_max &&
4259 		    mddev->ro == 0 &&
4260 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4261 			return -EBUSY;
4262 
4263 		/* Must be a multiple of chunk_size */
4264 		if (mddev->chunk_sectors) {
4265 			sector_t temp = max;
4266 			if (sector_div(temp, mddev->chunk_sectors))
4267 				return -EINVAL;
4268 		}
4269 		mddev->resync_max = max;
4270 	}
4271 	wake_up(&mddev->recovery_wait);
4272 	return len;
4273 }
4274 
4275 static struct md_sysfs_entry md_max_sync =
4276 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4277 
4278 static ssize_t
4279 suspend_lo_show(mddev_t *mddev, char *page)
4280 {
4281 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4282 }
4283 
4284 static ssize_t
4285 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
4286 {
4287 	char *e;
4288 	unsigned long long new = simple_strtoull(buf, &e, 10);
4289 	unsigned long long old = mddev->suspend_lo;
4290 
4291 	if (mddev->pers == NULL ||
4292 	    mddev->pers->quiesce == NULL)
4293 		return -EINVAL;
4294 	if (buf == e || (*e && *e != '\n'))
4295 		return -EINVAL;
4296 
4297 	mddev->suspend_lo = new;
4298 	if (new >= old)
4299 		/* Shrinking suspended region */
4300 		mddev->pers->quiesce(mddev, 2);
4301 	else {
4302 		/* Expanding suspended region - need to wait */
4303 		mddev->pers->quiesce(mddev, 1);
4304 		mddev->pers->quiesce(mddev, 0);
4305 	}
4306 	return len;
4307 }
4308 static struct md_sysfs_entry md_suspend_lo =
4309 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4310 
4311 
4312 static ssize_t
4313 suspend_hi_show(mddev_t *mddev, char *page)
4314 {
4315 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4316 }
4317 
4318 static ssize_t
4319 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
4320 {
4321 	char *e;
4322 	unsigned long long new = simple_strtoull(buf, &e, 10);
4323 	unsigned long long old = mddev->suspend_hi;
4324 
4325 	if (mddev->pers == NULL ||
4326 	    mddev->pers->quiesce == NULL)
4327 		return -EINVAL;
4328 	if (buf == e || (*e && *e != '\n'))
4329 		return -EINVAL;
4330 
4331 	mddev->suspend_hi = new;
4332 	if (new <= old)
4333 		/* Shrinking suspended region */
4334 		mddev->pers->quiesce(mddev, 2);
4335 	else {
4336 		/* Expanding suspended region - need to wait */
4337 		mddev->pers->quiesce(mddev, 1);
4338 		mddev->pers->quiesce(mddev, 0);
4339 	}
4340 	return len;
4341 }
4342 static struct md_sysfs_entry md_suspend_hi =
4343 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4344 
4345 static ssize_t
4346 reshape_position_show(mddev_t *mddev, char *page)
4347 {
4348 	if (mddev->reshape_position != MaxSector)
4349 		return sprintf(page, "%llu\n",
4350 			       (unsigned long long)mddev->reshape_position);
4351 	strcpy(page, "none\n");
4352 	return 5;
4353 }
4354 
4355 static ssize_t
4356 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
4357 {
4358 	char *e;
4359 	unsigned long long new = simple_strtoull(buf, &e, 10);
4360 	if (mddev->pers)
4361 		return -EBUSY;
4362 	if (buf == e || (*e && *e != '\n'))
4363 		return -EINVAL;
4364 	mddev->reshape_position = new;
4365 	mddev->delta_disks = 0;
4366 	mddev->new_level = mddev->level;
4367 	mddev->new_layout = mddev->layout;
4368 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4369 	return len;
4370 }
4371 
4372 static struct md_sysfs_entry md_reshape_position =
4373 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4374        reshape_position_store);
4375 
4376 static ssize_t
4377 array_size_show(mddev_t *mddev, char *page)
4378 {
4379 	if (mddev->external_size)
4380 		return sprintf(page, "%llu\n",
4381 			       (unsigned long long)mddev->array_sectors/2);
4382 	else
4383 		return sprintf(page, "default\n");
4384 }
4385 
4386 static ssize_t
4387 array_size_store(mddev_t *mddev, const char *buf, size_t len)
4388 {
4389 	sector_t sectors;
4390 
4391 	if (strncmp(buf, "default", 7) == 0) {
4392 		if (mddev->pers)
4393 			sectors = mddev->pers->size(mddev, 0, 0);
4394 		else
4395 			sectors = mddev->array_sectors;
4396 
4397 		mddev->external_size = 0;
4398 	} else {
4399 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4400 			return -EINVAL;
4401 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4402 			return -E2BIG;
4403 
4404 		mddev->external_size = 1;
4405 	}
4406 
4407 	mddev->array_sectors = sectors;
4408 	if (mddev->pers) {
4409 		set_capacity(mddev->gendisk, mddev->array_sectors);
4410 		revalidate_disk(mddev->gendisk);
4411 	}
4412 	return len;
4413 }
4414 
4415 static struct md_sysfs_entry md_array_size =
4416 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4417        array_size_store);
4418 
4419 static struct attribute *md_default_attrs[] = {
4420 	&md_level.attr,
4421 	&md_layout.attr,
4422 	&md_raid_disks.attr,
4423 	&md_chunk_size.attr,
4424 	&md_size.attr,
4425 	&md_resync_start.attr,
4426 	&md_metadata.attr,
4427 	&md_new_device.attr,
4428 	&md_safe_delay.attr,
4429 	&md_array_state.attr,
4430 	&md_reshape_position.attr,
4431 	&md_array_size.attr,
4432 	&max_corr_read_errors.attr,
4433 	NULL,
4434 };
4435 
4436 static struct attribute *md_redundancy_attrs[] = {
4437 	&md_scan_mode.attr,
4438 	&md_mismatches.attr,
4439 	&md_sync_min.attr,
4440 	&md_sync_max.attr,
4441 	&md_sync_speed.attr,
4442 	&md_sync_force_parallel.attr,
4443 	&md_sync_completed.attr,
4444 	&md_min_sync.attr,
4445 	&md_max_sync.attr,
4446 	&md_suspend_lo.attr,
4447 	&md_suspend_hi.attr,
4448 	&md_bitmap.attr,
4449 	&md_degraded.attr,
4450 	NULL,
4451 };
4452 static struct attribute_group md_redundancy_group = {
4453 	.name = NULL,
4454 	.attrs = md_redundancy_attrs,
4455 };
4456 
4457 
4458 static ssize_t
4459 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4460 {
4461 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4462 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4463 	ssize_t rv;
4464 
4465 	if (!entry->show)
4466 		return -EIO;
4467 	rv = mddev_lock(mddev);
4468 	if (!rv) {
4469 		rv = entry->show(mddev, page);
4470 		mddev_unlock(mddev);
4471 	}
4472 	return rv;
4473 }
4474 
4475 static ssize_t
4476 md_attr_store(struct kobject *kobj, struct attribute *attr,
4477 	      const char *page, size_t length)
4478 {
4479 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4480 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4481 	ssize_t rv;
4482 
4483 	if (!entry->store)
4484 		return -EIO;
4485 	if (!capable(CAP_SYS_ADMIN))
4486 		return -EACCES;
4487 	rv = mddev_lock(mddev);
4488 	if (mddev->hold_active == UNTIL_IOCTL)
4489 		mddev->hold_active = 0;
4490 	if (!rv) {
4491 		rv = entry->store(mddev, page, length);
4492 		mddev_unlock(mddev);
4493 	}
4494 	return rv;
4495 }
4496 
4497 static void md_free(struct kobject *ko)
4498 {
4499 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
4500 
4501 	if (mddev->sysfs_state)
4502 		sysfs_put(mddev->sysfs_state);
4503 
4504 	if (mddev->gendisk) {
4505 		del_gendisk(mddev->gendisk);
4506 		put_disk(mddev->gendisk);
4507 	}
4508 	if (mddev->queue)
4509 		blk_cleanup_queue(mddev->queue);
4510 
4511 	kfree(mddev);
4512 }
4513 
4514 static const struct sysfs_ops md_sysfs_ops = {
4515 	.show	= md_attr_show,
4516 	.store	= md_attr_store,
4517 };
4518 static struct kobj_type md_ktype = {
4519 	.release	= md_free,
4520 	.sysfs_ops	= &md_sysfs_ops,
4521 	.default_attrs	= md_default_attrs,
4522 };
4523 
4524 int mdp_major = 0;
4525 
4526 static void mddev_delayed_delete(struct work_struct *ws)
4527 {
4528 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
4529 
4530 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4531 	kobject_del(&mddev->kobj);
4532 	kobject_put(&mddev->kobj);
4533 }
4534 
4535 static int md_alloc(dev_t dev, char *name)
4536 {
4537 	static DEFINE_MUTEX(disks_mutex);
4538 	mddev_t *mddev = mddev_find(dev);
4539 	struct gendisk *disk;
4540 	int partitioned;
4541 	int shift;
4542 	int unit;
4543 	int error;
4544 
4545 	if (!mddev)
4546 		return -ENODEV;
4547 
4548 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4549 	shift = partitioned ? MdpMinorShift : 0;
4550 	unit = MINOR(mddev->unit) >> shift;
4551 
4552 	/* wait for any previous instance of this device to be
4553 	 * completely removed (mddev_delayed_delete).
4554 	 */
4555 	flush_workqueue(md_misc_wq);
4556 
4557 	mutex_lock(&disks_mutex);
4558 	error = -EEXIST;
4559 	if (mddev->gendisk)
4560 		goto abort;
4561 
4562 	if (name) {
4563 		/* Need to ensure that 'name' is not a duplicate.
4564 		 */
4565 		mddev_t *mddev2;
4566 		spin_lock(&all_mddevs_lock);
4567 
4568 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4569 			if (mddev2->gendisk &&
4570 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4571 				spin_unlock(&all_mddevs_lock);
4572 				goto abort;
4573 			}
4574 		spin_unlock(&all_mddevs_lock);
4575 	}
4576 
4577 	error = -ENOMEM;
4578 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4579 	if (!mddev->queue)
4580 		goto abort;
4581 	mddev->queue->queuedata = mddev;
4582 
4583 	blk_queue_make_request(mddev->queue, md_make_request);
4584 
4585 	disk = alloc_disk(1 << shift);
4586 	if (!disk) {
4587 		blk_cleanup_queue(mddev->queue);
4588 		mddev->queue = NULL;
4589 		goto abort;
4590 	}
4591 	disk->major = MAJOR(mddev->unit);
4592 	disk->first_minor = unit << shift;
4593 	if (name)
4594 		strcpy(disk->disk_name, name);
4595 	else if (partitioned)
4596 		sprintf(disk->disk_name, "md_d%d", unit);
4597 	else
4598 		sprintf(disk->disk_name, "md%d", unit);
4599 	disk->fops = &md_fops;
4600 	disk->private_data = mddev;
4601 	disk->queue = mddev->queue;
4602 	blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4603 	/* Allow extended partitions.  This makes the
4604 	 * 'mdp' device redundant, but we can't really
4605 	 * remove it now.
4606 	 */
4607 	disk->flags |= GENHD_FL_EXT_DEVT;
4608 	mddev->gendisk = disk;
4609 	/* As soon as we call add_disk(), another thread could get
4610 	 * through to md_open, so make sure it doesn't get too far
4611 	 */
4612 	mutex_lock(&mddev->open_mutex);
4613 	add_disk(disk);
4614 
4615 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4616 				     &disk_to_dev(disk)->kobj, "%s", "md");
4617 	if (error) {
4618 		/* This isn't possible, but as kobject_init_and_add is marked
4619 		 * __must_check, we must do something with the result
4620 		 */
4621 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4622 		       disk->disk_name);
4623 		error = 0;
4624 	}
4625 	if (mddev->kobj.sd &&
4626 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4627 		printk(KERN_DEBUG "pointless warning\n");
4628 	mutex_unlock(&mddev->open_mutex);
4629  abort:
4630 	mutex_unlock(&disks_mutex);
4631 	if (!error && mddev->kobj.sd) {
4632 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4633 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4634 	}
4635 	mddev_put(mddev);
4636 	return error;
4637 }
4638 
4639 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4640 {
4641 	md_alloc(dev, NULL);
4642 	return NULL;
4643 }
4644 
4645 static int add_named_array(const char *val, struct kernel_param *kp)
4646 {
4647 	/* val must be "md_*" where * is not all digits.
4648 	 * We allocate an array with a large free minor number, and
4649 	 * set the name to val.  val must not already be an active name.
4650 	 */
4651 	int len = strlen(val);
4652 	char buf[DISK_NAME_LEN];
4653 
4654 	while (len && val[len-1] == '\n')
4655 		len--;
4656 	if (len >= DISK_NAME_LEN)
4657 		return -E2BIG;
4658 	strlcpy(buf, val, len+1);
4659 	if (strncmp(buf, "md_", 3) != 0)
4660 		return -EINVAL;
4661 	return md_alloc(0, buf);
4662 }
4663 
4664 static void md_safemode_timeout(unsigned long data)
4665 {
4666 	mddev_t *mddev = (mddev_t *) data;
4667 
4668 	if (!atomic_read(&mddev->writes_pending)) {
4669 		mddev->safemode = 1;
4670 		if (mddev->external)
4671 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4672 	}
4673 	md_wakeup_thread(mddev->thread);
4674 }
4675 
4676 static int start_dirty_degraded;
4677 
4678 int md_run(mddev_t *mddev)
4679 {
4680 	int err;
4681 	mdk_rdev_t *rdev;
4682 	struct mdk_personality *pers;
4683 
4684 	if (list_empty(&mddev->disks))
4685 		/* cannot run an array with no devices.. */
4686 		return -EINVAL;
4687 
4688 	if (mddev->pers)
4689 		return -EBUSY;
4690 	/* Cannot run until previous stop completes properly */
4691 	if (mddev->sysfs_active)
4692 		return -EBUSY;
4693 
4694 	/*
4695 	 * Analyze all RAID superblock(s)
4696 	 */
4697 	if (!mddev->raid_disks) {
4698 		if (!mddev->persistent)
4699 			return -EINVAL;
4700 		analyze_sbs(mddev);
4701 	}
4702 
4703 	if (mddev->level != LEVEL_NONE)
4704 		request_module("md-level-%d", mddev->level);
4705 	else if (mddev->clevel[0])
4706 		request_module("md-%s", mddev->clevel);
4707 
4708 	/*
4709 	 * Drop all container device buffers, from now on
4710 	 * the only valid external interface is through the md
4711 	 * device.
4712 	 */
4713 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4714 		if (test_bit(Faulty, &rdev->flags))
4715 			continue;
4716 		sync_blockdev(rdev->bdev);
4717 		invalidate_bdev(rdev->bdev);
4718 
4719 		/* perform some consistency tests on the device.
4720 		 * We don't want the data to overlap the metadata,
4721 		 * Internal Bitmap issues have been handled elsewhere.
4722 		 */
4723 		if (rdev->meta_bdev) {
4724 			/* Nothing to check */;
4725 		} else if (rdev->data_offset < rdev->sb_start) {
4726 			if (mddev->dev_sectors &&
4727 			    rdev->data_offset + mddev->dev_sectors
4728 			    > rdev->sb_start) {
4729 				printk("md: %s: data overlaps metadata\n",
4730 				       mdname(mddev));
4731 				return -EINVAL;
4732 			}
4733 		} else {
4734 			if (rdev->sb_start + rdev->sb_size/512
4735 			    > rdev->data_offset) {
4736 				printk("md: %s: metadata overlaps data\n",
4737 				       mdname(mddev));
4738 				return -EINVAL;
4739 			}
4740 		}
4741 		sysfs_notify_dirent_safe(rdev->sysfs_state);
4742 	}
4743 
4744 	if (mddev->bio_set == NULL)
4745 		mddev->bio_set = bioset_create(BIO_POOL_SIZE,
4746 					       sizeof(mddev_t *));
4747 
4748 	spin_lock(&pers_lock);
4749 	pers = find_pers(mddev->level, mddev->clevel);
4750 	if (!pers || !try_module_get(pers->owner)) {
4751 		spin_unlock(&pers_lock);
4752 		if (mddev->level != LEVEL_NONE)
4753 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4754 			       mddev->level);
4755 		else
4756 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4757 			       mddev->clevel);
4758 		return -EINVAL;
4759 	}
4760 	mddev->pers = pers;
4761 	spin_unlock(&pers_lock);
4762 	if (mddev->level != pers->level) {
4763 		mddev->level = pers->level;
4764 		mddev->new_level = pers->level;
4765 	}
4766 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4767 
4768 	if (mddev->reshape_position != MaxSector &&
4769 	    pers->start_reshape == NULL) {
4770 		/* This personality cannot handle reshaping... */
4771 		mddev->pers = NULL;
4772 		module_put(pers->owner);
4773 		return -EINVAL;
4774 	}
4775 
4776 	if (pers->sync_request) {
4777 		/* Warn if this is a potentially silly
4778 		 * configuration.
4779 		 */
4780 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4781 		mdk_rdev_t *rdev2;
4782 		int warned = 0;
4783 
4784 		list_for_each_entry(rdev, &mddev->disks, same_set)
4785 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4786 				if (rdev < rdev2 &&
4787 				    rdev->bdev->bd_contains ==
4788 				    rdev2->bdev->bd_contains) {
4789 					printk(KERN_WARNING
4790 					       "%s: WARNING: %s appears to be"
4791 					       " on the same physical disk as"
4792 					       " %s.\n",
4793 					       mdname(mddev),
4794 					       bdevname(rdev->bdev,b),
4795 					       bdevname(rdev2->bdev,b2));
4796 					warned = 1;
4797 				}
4798 			}
4799 
4800 		if (warned)
4801 			printk(KERN_WARNING
4802 			       "True protection against single-disk"
4803 			       " failure might be compromised.\n");
4804 	}
4805 
4806 	mddev->recovery = 0;
4807 	/* may be over-ridden by personality */
4808 	mddev->resync_max_sectors = mddev->dev_sectors;
4809 
4810 	mddev->ok_start_degraded = start_dirty_degraded;
4811 
4812 	if (start_readonly && mddev->ro == 0)
4813 		mddev->ro = 2; /* read-only, but switch on first write */
4814 
4815 	err = mddev->pers->run(mddev);
4816 	if (err)
4817 		printk(KERN_ERR "md: pers->run() failed ...\n");
4818 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4819 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4820 			  " but 'external_size' not in effect?\n", __func__);
4821 		printk(KERN_ERR
4822 		       "md: invalid array_size %llu > default size %llu\n",
4823 		       (unsigned long long)mddev->array_sectors / 2,
4824 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4825 		err = -EINVAL;
4826 		mddev->pers->stop(mddev);
4827 	}
4828 	if (err == 0 && mddev->pers->sync_request) {
4829 		err = bitmap_create(mddev);
4830 		if (err) {
4831 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4832 			       mdname(mddev), err);
4833 			mddev->pers->stop(mddev);
4834 		}
4835 	}
4836 	if (err) {
4837 		module_put(mddev->pers->owner);
4838 		mddev->pers = NULL;
4839 		bitmap_destroy(mddev);
4840 		return err;
4841 	}
4842 	if (mddev->pers->sync_request) {
4843 		if (mddev->kobj.sd &&
4844 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4845 			printk(KERN_WARNING
4846 			       "md: cannot register extra attributes for %s\n",
4847 			       mdname(mddev));
4848 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
4849 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4850 		mddev->ro = 0;
4851 
4852  	atomic_set(&mddev->writes_pending,0);
4853 	atomic_set(&mddev->max_corr_read_errors,
4854 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
4855 	mddev->safemode = 0;
4856 	mddev->safemode_timer.function = md_safemode_timeout;
4857 	mddev->safemode_timer.data = (unsigned long) mddev;
4858 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4859 	mddev->in_sync = 1;
4860 	smp_wmb();
4861 	mddev->ready = 1;
4862 	list_for_each_entry(rdev, &mddev->disks, same_set)
4863 		if (rdev->raid_disk >= 0)
4864 			if (sysfs_link_rdev(mddev, rdev))
4865 				/* failure here is OK */;
4866 
4867 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4868 
4869 	if (mddev->flags)
4870 		md_update_sb(mddev, 0);
4871 
4872 	md_new_event(mddev);
4873 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4874 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4875 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4876 	return 0;
4877 }
4878 EXPORT_SYMBOL_GPL(md_run);
4879 
4880 static int do_md_run(mddev_t *mddev)
4881 {
4882 	int err;
4883 
4884 	err = md_run(mddev);
4885 	if (err)
4886 		goto out;
4887 	err = bitmap_load(mddev);
4888 	if (err) {
4889 		bitmap_destroy(mddev);
4890 		goto out;
4891 	}
4892 
4893 	md_wakeup_thread(mddev->thread);
4894 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4895 
4896 	set_capacity(mddev->gendisk, mddev->array_sectors);
4897 	revalidate_disk(mddev->gendisk);
4898 	mddev->changed = 1;
4899 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4900 out:
4901 	return err;
4902 }
4903 
4904 static int restart_array(mddev_t *mddev)
4905 {
4906 	struct gendisk *disk = mddev->gendisk;
4907 
4908 	/* Complain if it has no devices */
4909 	if (list_empty(&mddev->disks))
4910 		return -ENXIO;
4911 	if (!mddev->pers)
4912 		return -EINVAL;
4913 	if (!mddev->ro)
4914 		return -EBUSY;
4915 	mddev->safemode = 0;
4916 	mddev->ro = 0;
4917 	set_disk_ro(disk, 0);
4918 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4919 		mdname(mddev));
4920 	/* Kick recovery or resync if necessary */
4921 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4922 	md_wakeup_thread(mddev->thread);
4923 	md_wakeup_thread(mddev->sync_thread);
4924 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4925 	return 0;
4926 }
4927 
4928 /* similar to deny_write_access, but accounts for our holding a reference
4929  * to the file ourselves */
4930 static int deny_bitmap_write_access(struct file * file)
4931 {
4932 	struct inode *inode = file->f_mapping->host;
4933 
4934 	spin_lock(&inode->i_lock);
4935 	if (atomic_read(&inode->i_writecount) > 1) {
4936 		spin_unlock(&inode->i_lock);
4937 		return -ETXTBSY;
4938 	}
4939 	atomic_set(&inode->i_writecount, -1);
4940 	spin_unlock(&inode->i_lock);
4941 
4942 	return 0;
4943 }
4944 
4945 void restore_bitmap_write_access(struct file *file)
4946 {
4947 	struct inode *inode = file->f_mapping->host;
4948 
4949 	spin_lock(&inode->i_lock);
4950 	atomic_set(&inode->i_writecount, 1);
4951 	spin_unlock(&inode->i_lock);
4952 }
4953 
4954 static void md_clean(mddev_t *mddev)
4955 {
4956 	mddev->array_sectors = 0;
4957 	mddev->external_size = 0;
4958 	mddev->dev_sectors = 0;
4959 	mddev->raid_disks = 0;
4960 	mddev->recovery_cp = 0;
4961 	mddev->resync_min = 0;
4962 	mddev->resync_max = MaxSector;
4963 	mddev->reshape_position = MaxSector;
4964 	mddev->external = 0;
4965 	mddev->persistent = 0;
4966 	mddev->level = LEVEL_NONE;
4967 	mddev->clevel[0] = 0;
4968 	mddev->flags = 0;
4969 	mddev->ro = 0;
4970 	mddev->metadata_type[0] = 0;
4971 	mddev->chunk_sectors = 0;
4972 	mddev->ctime = mddev->utime = 0;
4973 	mddev->layout = 0;
4974 	mddev->max_disks = 0;
4975 	mddev->events = 0;
4976 	mddev->can_decrease_events = 0;
4977 	mddev->delta_disks = 0;
4978 	mddev->new_level = LEVEL_NONE;
4979 	mddev->new_layout = 0;
4980 	mddev->new_chunk_sectors = 0;
4981 	mddev->curr_resync = 0;
4982 	mddev->resync_mismatches = 0;
4983 	mddev->suspend_lo = mddev->suspend_hi = 0;
4984 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
4985 	mddev->recovery = 0;
4986 	mddev->in_sync = 0;
4987 	mddev->changed = 0;
4988 	mddev->degraded = 0;
4989 	mddev->safemode = 0;
4990 	mddev->bitmap_info.offset = 0;
4991 	mddev->bitmap_info.default_offset = 0;
4992 	mddev->bitmap_info.chunksize = 0;
4993 	mddev->bitmap_info.daemon_sleep = 0;
4994 	mddev->bitmap_info.max_write_behind = 0;
4995 }
4996 
4997 static void __md_stop_writes(mddev_t *mddev)
4998 {
4999 	if (mddev->sync_thread) {
5000 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5001 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5002 		reap_sync_thread(mddev);
5003 	}
5004 
5005 	del_timer_sync(&mddev->safemode_timer);
5006 
5007 	bitmap_flush(mddev);
5008 	md_super_wait(mddev);
5009 
5010 	if (!mddev->in_sync || mddev->flags) {
5011 		/* mark array as shutdown cleanly */
5012 		mddev->in_sync = 1;
5013 		md_update_sb(mddev, 1);
5014 	}
5015 }
5016 
5017 void md_stop_writes(mddev_t *mddev)
5018 {
5019 	mddev_lock(mddev);
5020 	__md_stop_writes(mddev);
5021 	mddev_unlock(mddev);
5022 }
5023 EXPORT_SYMBOL_GPL(md_stop_writes);
5024 
5025 void md_stop(mddev_t *mddev)
5026 {
5027 	mddev->ready = 0;
5028 	mddev->pers->stop(mddev);
5029 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
5030 		mddev->to_remove = &md_redundancy_group;
5031 	module_put(mddev->pers->owner);
5032 	mddev->pers = NULL;
5033 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5034 }
5035 EXPORT_SYMBOL_GPL(md_stop);
5036 
5037 static int md_set_readonly(mddev_t *mddev, int is_open)
5038 {
5039 	int err = 0;
5040 	mutex_lock(&mddev->open_mutex);
5041 	if (atomic_read(&mddev->openers) > is_open) {
5042 		printk("md: %s still in use.\n",mdname(mddev));
5043 		err = -EBUSY;
5044 		goto out;
5045 	}
5046 	if (mddev->pers) {
5047 		__md_stop_writes(mddev);
5048 
5049 		err  = -ENXIO;
5050 		if (mddev->ro==1)
5051 			goto out;
5052 		mddev->ro = 1;
5053 		set_disk_ro(mddev->gendisk, 1);
5054 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5055 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5056 		err = 0;
5057 	}
5058 out:
5059 	mutex_unlock(&mddev->open_mutex);
5060 	return err;
5061 }
5062 
5063 /* mode:
5064  *   0 - completely stop and dis-assemble array
5065  *   2 - stop but do not disassemble array
5066  */
5067 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
5068 {
5069 	struct gendisk *disk = mddev->gendisk;
5070 	mdk_rdev_t *rdev;
5071 
5072 	mutex_lock(&mddev->open_mutex);
5073 	if (atomic_read(&mddev->openers) > is_open ||
5074 	    mddev->sysfs_active) {
5075 		printk("md: %s still in use.\n",mdname(mddev));
5076 		mutex_unlock(&mddev->open_mutex);
5077 		return -EBUSY;
5078 	}
5079 
5080 	if (mddev->pers) {
5081 		if (mddev->ro)
5082 			set_disk_ro(disk, 0);
5083 
5084 		__md_stop_writes(mddev);
5085 		md_stop(mddev);
5086 		mddev->queue->merge_bvec_fn = NULL;
5087 		mddev->queue->backing_dev_info.congested_fn = NULL;
5088 
5089 		/* tell userspace to handle 'inactive' */
5090 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5091 
5092 		list_for_each_entry(rdev, &mddev->disks, same_set)
5093 			if (rdev->raid_disk >= 0)
5094 				sysfs_unlink_rdev(mddev, rdev);
5095 
5096 		set_capacity(disk, 0);
5097 		mutex_unlock(&mddev->open_mutex);
5098 		mddev->changed = 1;
5099 		revalidate_disk(disk);
5100 
5101 		if (mddev->ro)
5102 			mddev->ro = 0;
5103 	} else
5104 		mutex_unlock(&mddev->open_mutex);
5105 	/*
5106 	 * Free resources if final stop
5107 	 */
5108 	if (mode == 0) {
5109 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5110 
5111 		bitmap_destroy(mddev);
5112 		if (mddev->bitmap_info.file) {
5113 			restore_bitmap_write_access(mddev->bitmap_info.file);
5114 			fput(mddev->bitmap_info.file);
5115 			mddev->bitmap_info.file = NULL;
5116 		}
5117 		mddev->bitmap_info.offset = 0;
5118 
5119 		export_array(mddev);
5120 
5121 		md_clean(mddev);
5122 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5123 		if (mddev->hold_active == UNTIL_STOP)
5124 			mddev->hold_active = 0;
5125 	}
5126 	blk_integrity_unregister(disk);
5127 	md_new_event(mddev);
5128 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5129 	return 0;
5130 }
5131 
5132 #ifndef MODULE
5133 static void autorun_array(mddev_t *mddev)
5134 {
5135 	mdk_rdev_t *rdev;
5136 	int err;
5137 
5138 	if (list_empty(&mddev->disks))
5139 		return;
5140 
5141 	printk(KERN_INFO "md: running: ");
5142 
5143 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5144 		char b[BDEVNAME_SIZE];
5145 		printk("<%s>", bdevname(rdev->bdev,b));
5146 	}
5147 	printk("\n");
5148 
5149 	err = do_md_run(mddev);
5150 	if (err) {
5151 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5152 		do_md_stop(mddev, 0, 0);
5153 	}
5154 }
5155 
5156 /*
5157  * lets try to run arrays based on all disks that have arrived
5158  * until now. (those are in pending_raid_disks)
5159  *
5160  * the method: pick the first pending disk, collect all disks with
5161  * the same UUID, remove all from the pending list and put them into
5162  * the 'same_array' list. Then order this list based on superblock
5163  * update time (freshest comes first), kick out 'old' disks and
5164  * compare superblocks. If everything's fine then run it.
5165  *
5166  * If "unit" is allocated, then bump its reference count
5167  */
5168 static void autorun_devices(int part)
5169 {
5170 	mdk_rdev_t *rdev0, *rdev, *tmp;
5171 	mddev_t *mddev;
5172 	char b[BDEVNAME_SIZE];
5173 
5174 	printk(KERN_INFO "md: autorun ...\n");
5175 	while (!list_empty(&pending_raid_disks)) {
5176 		int unit;
5177 		dev_t dev;
5178 		LIST_HEAD(candidates);
5179 		rdev0 = list_entry(pending_raid_disks.next,
5180 					 mdk_rdev_t, same_set);
5181 
5182 		printk(KERN_INFO "md: considering %s ...\n",
5183 			bdevname(rdev0->bdev,b));
5184 		INIT_LIST_HEAD(&candidates);
5185 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5186 			if (super_90_load(rdev, rdev0, 0) >= 0) {
5187 				printk(KERN_INFO "md:  adding %s ...\n",
5188 					bdevname(rdev->bdev,b));
5189 				list_move(&rdev->same_set, &candidates);
5190 			}
5191 		/*
5192 		 * now we have a set of devices, with all of them having
5193 		 * mostly sane superblocks. It's time to allocate the
5194 		 * mddev.
5195 		 */
5196 		if (part) {
5197 			dev = MKDEV(mdp_major,
5198 				    rdev0->preferred_minor << MdpMinorShift);
5199 			unit = MINOR(dev) >> MdpMinorShift;
5200 		} else {
5201 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5202 			unit = MINOR(dev);
5203 		}
5204 		if (rdev0->preferred_minor != unit) {
5205 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5206 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5207 			break;
5208 		}
5209 
5210 		md_probe(dev, NULL, NULL);
5211 		mddev = mddev_find(dev);
5212 		if (!mddev || !mddev->gendisk) {
5213 			if (mddev)
5214 				mddev_put(mddev);
5215 			printk(KERN_ERR
5216 				"md: cannot allocate memory for md drive.\n");
5217 			break;
5218 		}
5219 		if (mddev_lock(mddev))
5220 			printk(KERN_WARNING "md: %s locked, cannot run\n",
5221 			       mdname(mddev));
5222 		else if (mddev->raid_disks || mddev->major_version
5223 			 || !list_empty(&mddev->disks)) {
5224 			printk(KERN_WARNING
5225 				"md: %s already running, cannot run %s\n",
5226 				mdname(mddev), bdevname(rdev0->bdev,b));
5227 			mddev_unlock(mddev);
5228 		} else {
5229 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
5230 			mddev->persistent = 1;
5231 			rdev_for_each_list(rdev, tmp, &candidates) {
5232 				list_del_init(&rdev->same_set);
5233 				if (bind_rdev_to_array(rdev, mddev))
5234 					export_rdev(rdev);
5235 			}
5236 			autorun_array(mddev);
5237 			mddev_unlock(mddev);
5238 		}
5239 		/* on success, candidates will be empty, on error
5240 		 * it won't...
5241 		 */
5242 		rdev_for_each_list(rdev, tmp, &candidates) {
5243 			list_del_init(&rdev->same_set);
5244 			export_rdev(rdev);
5245 		}
5246 		mddev_put(mddev);
5247 	}
5248 	printk(KERN_INFO "md: ... autorun DONE.\n");
5249 }
5250 #endif /* !MODULE */
5251 
5252 static int get_version(void __user * arg)
5253 {
5254 	mdu_version_t ver;
5255 
5256 	ver.major = MD_MAJOR_VERSION;
5257 	ver.minor = MD_MINOR_VERSION;
5258 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
5259 
5260 	if (copy_to_user(arg, &ver, sizeof(ver)))
5261 		return -EFAULT;
5262 
5263 	return 0;
5264 }
5265 
5266 static int get_array_info(mddev_t * mddev, void __user * arg)
5267 {
5268 	mdu_array_info_t info;
5269 	int nr,working,insync,failed,spare;
5270 	mdk_rdev_t *rdev;
5271 
5272 	nr=working=insync=failed=spare=0;
5273 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5274 		nr++;
5275 		if (test_bit(Faulty, &rdev->flags))
5276 			failed++;
5277 		else {
5278 			working++;
5279 			if (test_bit(In_sync, &rdev->flags))
5280 				insync++;
5281 			else
5282 				spare++;
5283 		}
5284 	}
5285 
5286 	info.major_version = mddev->major_version;
5287 	info.minor_version = mddev->minor_version;
5288 	info.patch_version = MD_PATCHLEVEL_VERSION;
5289 	info.ctime         = mddev->ctime;
5290 	info.level         = mddev->level;
5291 	info.size          = mddev->dev_sectors / 2;
5292 	if (info.size != mddev->dev_sectors / 2) /* overflow */
5293 		info.size = -1;
5294 	info.nr_disks      = nr;
5295 	info.raid_disks    = mddev->raid_disks;
5296 	info.md_minor      = mddev->md_minor;
5297 	info.not_persistent= !mddev->persistent;
5298 
5299 	info.utime         = mddev->utime;
5300 	info.state         = 0;
5301 	if (mddev->in_sync)
5302 		info.state = (1<<MD_SB_CLEAN);
5303 	if (mddev->bitmap && mddev->bitmap_info.offset)
5304 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5305 	info.active_disks  = insync;
5306 	info.working_disks = working;
5307 	info.failed_disks  = failed;
5308 	info.spare_disks   = spare;
5309 
5310 	info.layout        = mddev->layout;
5311 	info.chunk_size    = mddev->chunk_sectors << 9;
5312 
5313 	if (copy_to_user(arg, &info, sizeof(info)))
5314 		return -EFAULT;
5315 
5316 	return 0;
5317 }
5318 
5319 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
5320 {
5321 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5322 	char *ptr, *buf = NULL;
5323 	int err = -ENOMEM;
5324 
5325 	if (md_allow_write(mddev))
5326 		file = kmalloc(sizeof(*file), GFP_NOIO);
5327 	else
5328 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5329 
5330 	if (!file)
5331 		goto out;
5332 
5333 	/* bitmap disabled, zero the first byte and copy out */
5334 	if (!mddev->bitmap || !mddev->bitmap->file) {
5335 		file->pathname[0] = '\0';
5336 		goto copy_out;
5337 	}
5338 
5339 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5340 	if (!buf)
5341 		goto out;
5342 
5343 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
5344 	if (IS_ERR(ptr))
5345 		goto out;
5346 
5347 	strcpy(file->pathname, ptr);
5348 
5349 copy_out:
5350 	err = 0;
5351 	if (copy_to_user(arg, file, sizeof(*file)))
5352 		err = -EFAULT;
5353 out:
5354 	kfree(buf);
5355 	kfree(file);
5356 	return err;
5357 }
5358 
5359 static int get_disk_info(mddev_t * mddev, void __user * arg)
5360 {
5361 	mdu_disk_info_t info;
5362 	mdk_rdev_t *rdev;
5363 
5364 	if (copy_from_user(&info, arg, sizeof(info)))
5365 		return -EFAULT;
5366 
5367 	rdev = find_rdev_nr(mddev, info.number);
5368 	if (rdev) {
5369 		info.major = MAJOR(rdev->bdev->bd_dev);
5370 		info.minor = MINOR(rdev->bdev->bd_dev);
5371 		info.raid_disk = rdev->raid_disk;
5372 		info.state = 0;
5373 		if (test_bit(Faulty, &rdev->flags))
5374 			info.state |= (1<<MD_DISK_FAULTY);
5375 		else if (test_bit(In_sync, &rdev->flags)) {
5376 			info.state |= (1<<MD_DISK_ACTIVE);
5377 			info.state |= (1<<MD_DISK_SYNC);
5378 		}
5379 		if (test_bit(WriteMostly, &rdev->flags))
5380 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5381 	} else {
5382 		info.major = info.minor = 0;
5383 		info.raid_disk = -1;
5384 		info.state = (1<<MD_DISK_REMOVED);
5385 	}
5386 
5387 	if (copy_to_user(arg, &info, sizeof(info)))
5388 		return -EFAULT;
5389 
5390 	return 0;
5391 }
5392 
5393 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5394 {
5395 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5396 	mdk_rdev_t *rdev;
5397 	dev_t dev = MKDEV(info->major,info->minor);
5398 
5399 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5400 		return -EOVERFLOW;
5401 
5402 	if (!mddev->raid_disks) {
5403 		int err;
5404 		/* expecting a device which has a superblock */
5405 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5406 		if (IS_ERR(rdev)) {
5407 			printk(KERN_WARNING
5408 				"md: md_import_device returned %ld\n",
5409 				PTR_ERR(rdev));
5410 			return PTR_ERR(rdev);
5411 		}
5412 		if (!list_empty(&mddev->disks)) {
5413 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
5414 							mdk_rdev_t, same_set);
5415 			err = super_types[mddev->major_version]
5416 				.load_super(rdev, rdev0, mddev->minor_version);
5417 			if (err < 0) {
5418 				printk(KERN_WARNING
5419 					"md: %s has different UUID to %s\n",
5420 					bdevname(rdev->bdev,b),
5421 					bdevname(rdev0->bdev,b2));
5422 				export_rdev(rdev);
5423 				return -EINVAL;
5424 			}
5425 		}
5426 		err = bind_rdev_to_array(rdev, mddev);
5427 		if (err)
5428 			export_rdev(rdev);
5429 		return err;
5430 	}
5431 
5432 	/*
5433 	 * add_new_disk can be used once the array is assembled
5434 	 * to add "hot spares".  They must already have a superblock
5435 	 * written
5436 	 */
5437 	if (mddev->pers) {
5438 		int err;
5439 		if (!mddev->pers->hot_add_disk) {
5440 			printk(KERN_WARNING
5441 				"%s: personality does not support diskops!\n",
5442 			       mdname(mddev));
5443 			return -EINVAL;
5444 		}
5445 		if (mddev->persistent)
5446 			rdev = md_import_device(dev, mddev->major_version,
5447 						mddev->minor_version);
5448 		else
5449 			rdev = md_import_device(dev, -1, -1);
5450 		if (IS_ERR(rdev)) {
5451 			printk(KERN_WARNING
5452 				"md: md_import_device returned %ld\n",
5453 				PTR_ERR(rdev));
5454 			return PTR_ERR(rdev);
5455 		}
5456 		/* set saved_raid_disk if appropriate */
5457 		if (!mddev->persistent) {
5458 			if (info->state & (1<<MD_DISK_SYNC)  &&
5459 			    info->raid_disk < mddev->raid_disks) {
5460 				rdev->raid_disk = info->raid_disk;
5461 				set_bit(In_sync, &rdev->flags);
5462 			} else
5463 				rdev->raid_disk = -1;
5464 		} else
5465 			super_types[mddev->major_version].
5466 				validate_super(mddev, rdev);
5467 		if ((info->state & (1<<MD_DISK_SYNC)) &&
5468 		    (!test_bit(In_sync, &rdev->flags) ||
5469 		     rdev->raid_disk != info->raid_disk)) {
5470 			/* This was a hot-add request, but events doesn't
5471 			 * match, so reject it.
5472 			 */
5473 			export_rdev(rdev);
5474 			return -EINVAL;
5475 		}
5476 
5477 		if (test_bit(In_sync, &rdev->flags))
5478 			rdev->saved_raid_disk = rdev->raid_disk;
5479 		else
5480 			rdev->saved_raid_disk = -1;
5481 
5482 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5483 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5484 			set_bit(WriteMostly, &rdev->flags);
5485 		else
5486 			clear_bit(WriteMostly, &rdev->flags);
5487 
5488 		rdev->raid_disk = -1;
5489 		err = bind_rdev_to_array(rdev, mddev);
5490 		if (!err && !mddev->pers->hot_remove_disk) {
5491 			/* If there is hot_add_disk but no hot_remove_disk
5492 			 * then added disks for geometry changes,
5493 			 * and should be added immediately.
5494 			 */
5495 			super_types[mddev->major_version].
5496 				validate_super(mddev, rdev);
5497 			err = mddev->pers->hot_add_disk(mddev, rdev);
5498 			if (err)
5499 				unbind_rdev_from_array(rdev);
5500 		}
5501 		if (err)
5502 			export_rdev(rdev);
5503 		else
5504 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5505 
5506 		md_update_sb(mddev, 1);
5507 		if (mddev->degraded)
5508 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5509 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5510 		if (!err)
5511 			md_new_event(mddev);
5512 		md_wakeup_thread(mddev->thread);
5513 		return err;
5514 	}
5515 
5516 	/* otherwise, add_new_disk is only allowed
5517 	 * for major_version==0 superblocks
5518 	 */
5519 	if (mddev->major_version != 0) {
5520 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5521 		       mdname(mddev));
5522 		return -EINVAL;
5523 	}
5524 
5525 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5526 		int err;
5527 		rdev = md_import_device(dev, -1, 0);
5528 		if (IS_ERR(rdev)) {
5529 			printk(KERN_WARNING
5530 				"md: error, md_import_device() returned %ld\n",
5531 				PTR_ERR(rdev));
5532 			return PTR_ERR(rdev);
5533 		}
5534 		rdev->desc_nr = info->number;
5535 		if (info->raid_disk < mddev->raid_disks)
5536 			rdev->raid_disk = info->raid_disk;
5537 		else
5538 			rdev->raid_disk = -1;
5539 
5540 		if (rdev->raid_disk < mddev->raid_disks)
5541 			if (info->state & (1<<MD_DISK_SYNC))
5542 				set_bit(In_sync, &rdev->flags);
5543 
5544 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5545 			set_bit(WriteMostly, &rdev->flags);
5546 
5547 		if (!mddev->persistent) {
5548 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5549 			rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5550 		} else
5551 			rdev->sb_start = calc_dev_sboffset(rdev);
5552 		rdev->sectors = rdev->sb_start;
5553 
5554 		err = bind_rdev_to_array(rdev, mddev);
5555 		if (err) {
5556 			export_rdev(rdev);
5557 			return err;
5558 		}
5559 	}
5560 
5561 	return 0;
5562 }
5563 
5564 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
5565 {
5566 	char b[BDEVNAME_SIZE];
5567 	mdk_rdev_t *rdev;
5568 
5569 	rdev = find_rdev(mddev, dev);
5570 	if (!rdev)
5571 		return -ENXIO;
5572 
5573 	if (rdev->raid_disk >= 0)
5574 		goto busy;
5575 
5576 	kick_rdev_from_array(rdev);
5577 	md_update_sb(mddev, 1);
5578 	md_new_event(mddev);
5579 
5580 	return 0;
5581 busy:
5582 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5583 		bdevname(rdev->bdev,b), mdname(mddev));
5584 	return -EBUSY;
5585 }
5586 
5587 static int hot_add_disk(mddev_t * mddev, dev_t dev)
5588 {
5589 	char b[BDEVNAME_SIZE];
5590 	int err;
5591 	mdk_rdev_t *rdev;
5592 
5593 	if (!mddev->pers)
5594 		return -ENODEV;
5595 
5596 	if (mddev->major_version != 0) {
5597 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5598 			" version-0 superblocks.\n",
5599 			mdname(mddev));
5600 		return -EINVAL;
5601 	}
5602 	if (!mddev->pers->hot_add_disk) {
5603 		printk(KERN_WARNING
5604 			"%s: personality does not support diskops!\n",
5605 			mdname(mddev));
5606 		return -EINVAL;
5607 	}
5608 
5609 	rdev = md_import_device(dev, -1, 0);
5610 	if (IS_ERR(rdev)) {
5611 		printk(KERN_WARNING
5612 			"md: error, md_import_device() returned %ld\n",
5613 			PTR_ERR(rdev));
5614 		return -EINVAL;
5615 	}
5616 
5617 	if (mddev->persistent)
5618 		rdev->sb_start = calc_dev_sboffset(rdev);
5619 	else
5620 		rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5621 
5622 	rdev->sectors = rdev->sb_start;
5623 
5624 	if (test_bit(Faulty, &rdev->flags)) {
5625 		printk(KERN_WARNING
5626 			"md: can not hot-add faulty %s disk to %s!\n",
5627 			bdevname(rdev->bdev,b), mdname(mddev));
5628 		err = -EINVAL;
5629 		goto abort_export;
5630 	}
5631 	clear_bit(In_sync, &rdev->flags);
5632 	rdev->desc_nr = -1;
5633 	rdev->saved_raid_disk = -1;
5634 	err = bind_rdev_to_array(rdev, mddev);
5635 	if (err)
5636 		goto abort_export;
5637 
5638 	/*
5639 	 * The rest should better be atomic, we can have disk failures
5640 	 * noticed in interrupt contexts ...
5641 	 */
5642 
5643 	rdev->raid_disk = -1;
5644 
5645 	md_update_sb(mddev, 1);
5646 
5647 	/*
5648 	 * Kick recovery, maybe this spare has to be added to the
5649 	 * array immediately.
5650 	 */
5651 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5652 	md_wakeup_thread(mddev->thread);
5653 	md_new_event(mddev);
5654 	return 0;
5655 
5656 abort_export:
5657 	export_rdev(rdev);
5658 	return err;
5659 }
5660 
5661 static int set_bitmap_file(mddev_t *mddev, int fd)
5662 {
5663 	int err;
5664 
5665 	if (mddev->pers) {
5666 		if (!mddev->pers->quiesce)
5667 			return -EBUSY;
5668 		if (mddev->recovery || mddev->sync_thread)
5669 			return -EBUSY;
5670 		/* we should be able to change the bitmap.. */
5671 	}
5672 
5673 
5674 	if (fd >= 0) {
5675 		if (mddev->bitmap)
5676 			return -EEXIST; /* cannot add when bitmap is present */
5677 		mddev->bitmap_info.file = fget(fd);
5678 
5679 		if (mddev->bitmap_info.file == NULL) {
5680 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5681 			       mdname(mddev));
5682 			return -EBADF;
5683 		}
5684 
5685 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5686 		if (err) {
5687 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5688 			       mdname(mddev));
5689 			fput(mddev->bitmap_info.file);
5690 			mddev->bitmap_info.file = NULL;
5691 			return err;
5692 		}
5693 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5694 	} else if (mddev->bitmap == NULL)
5695 		return -ENOENT; /* cannot remove what isn't there */
5696 	err = 0;
5697 	if (mddev->pers) {
5698 		mddev->pers->quiesce(mddev, 1);
5699 		if (fd >= 0) {
5700 			err = bitmap_create(mddev);
5701 			if (!err)
5702 				err = bitmap_load(mddev);
5703 		}
5704 		if (fd < 0 || err) {
5705 			bitmap_destroy(mddev);
5706 			fd = -1; /* make sure to put the file */
5707 		}
5708 		mddev->pers->quiesce(mddev, 0);
5709 	}
5710 	if (fd < 0) {
5711 		if (mddev->bitmap_info.file) {
5712 			restore_bitmap_write_access(mddev->bitmap_info.file);
5713 			fput(mddev->bitmap_info.file);
5714 		}
5715 		mddev->bitmap_info.file = NULL;
5716 	}
5717 
5718 	return err;
5719 }
5720 
5721 /*
5722  * set_array_info is used two different ways
5723  * The original usage is when creating a new array.
5724  * In this usage, raid_disks is > 0 and it together with
5725  *  level, size, not_persistent,layout,chunksize determine the
5726  *  shape of the array.
5727  *  This will always create an array with a type-0.90.0 superblock.
5728  * The newer usage is when assembling an array.
5729  *  In this case raid_disks will be 0, and the major_version field is
5730  *  use to determine which style super-blocks are to be found on the devices.
5731  *  The minor and patch _version numbers are also kept incase the
5732  *  super_block handler wishes to interpret them.
5733  */
5734 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5735 {
5736 
5737 	if (info->raid_disks == 0) {
5738 		/* just setting version number for superblock loading */
5739 		if (info->major_version < 0 ||
5740 		    info->major_version >= ARRAY_SIZE(super_types) ||
5741 		    super_types[info->major_version].name == NULL) {
5742 			/* maybe try to auto-load a module? */
5743 			printk(KERN_INFO
5744 				"md: superblock version %d not known\n",
5745 				info->major_version);
5746 			return -EINVAL;
5747 		}
5748 		mddev->major_version = info->major_version;
5749 		mddev->minor_version = info->minor_version;
5750 		mddev->patch_version = info->patch_version;
5751 		mddev->persistent = !info->not_persistent;
5752 		/* ensure mddev_put doesn't delete this now that there
5753 		 * is some minimal configuration.
5754 		 */
5755 		mddev->ctime         = get_seconds();
5756 		return 0;
5757 	}
5758 	mddev->major_version = MD_MAJOR_VERSION;
5759 	mddev->minor_version = MD_MINOR_VERSION;
5760 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5761 	mddev->ctime         = get_seconds();
5762 
5763 	mddev->level         = info->level;
5764 	mddev->clevel[0]     = 0;
5765 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5766 	mddev->raid_disks    = info->raid_disks;
5767 	/* don't set md_minor, it is determined by which /dev/md* was
5768 	 * openned
5769 	 */
5770 	if (info->state & (1<<MD_SB_CLEAN))
5771 		mddev->recovery_cp = MaxSector;
5772 	else
5773 		mddev->recovery_cp = 0;
5774 	mddev->persistent    = ! info->not_persistent;
5775 	mddev->external	     = 0;
5776 
5777 	mddev->layout        = info->layout;
5778 	mddev->chunk_sectors = info->chunk_size >> 9;
5779 
5780 	mddev->max_disks     = MD_SB_DISKS;
5781 
5782 	if (mddev->persistent)
5783 		mddev->flags         = 0;
5784 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5785 
5786 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
5787 	mddev->bitmap_info.offset = 0;
5788 
5789 	mddev->reshape_position = MaxSector;
5790 
5791 	/*
5792 	 * Generate a 128 bit UUID
5793 	 */
5794 	get_random_bytes(mddev->uuid, 16);
5795 
5796 	mddev->new_level = mddev->level;
5797 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5798 	mddev->new_layout = mddev->layout;
5799 	mddev->delta_disks = 0;
5800 
5801 	return 0;
5802 }
5803 
5804 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5805 {
5806 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5807 
5808 	if (mddev->external_size)
5809 		return;
5810 
5811 	mddev->array_sectors = array_sectors;
5812 }
5813 EXPORT_SYMBOL(md_set_array_sectors);
5814 
5815 static int update_size(mddev_t *mddev, sector_t num_sectors)
5816 {
5817 	mdk_rdev_t *rdev;
5818 	int rv;
5819 	int fit = (num_sectors == 0);
5820 
5821 	if (mddev->pers->resize == NULL)
5822 		return -EINVAL;
5823 	/* The "num_sectors" is the number of sectors of each device that
5824 	 * is used.  This can only make sense for arrays with redundancy.
5825 	 * linear and raid0 always use whatever space is available. We can only
5826 	 * consider changing this number if no resync or reconstruction is
5827 	 * happening, and if the new size is acceptable. It must fit before the
5828 	 * sb_start or, if that is <data_offset, it must fit before the size
5829 	 * of each device.  If num_sectors is zero, we find the largest size
5830 	 * that fits.
5831 	 */
5832 	if (mddev->sync_thread)
5833 		return -EBUSY;
5834 	if (mddev->bitmap)
5835 		/* Sorry, cannot grow a bitmap yet, just remove it,
5836 		 * grow, and re-add.
5837 		 */
5838 		return -EBUSY;
5839 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5840 		sector_t avail = rdev->sectors;
5841 
5842 		if (fit && (num_sectors == 0 || num_sectors > avail))
5843 			num_sectors = avail;
5844 		if (avail < num_sectors)
5845 			return -ENOSPC;
5846 	}
5847 	rv = mddev->pers->resize(mddev, num_sectors);
5848 	if (!rv)
5849 		revalidate_disk(mddev->gendisk);
5850 	return rv;
5851 }
5852 
5853 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5854 {
5855 	int rv;
5856 	/* change the number of raid disks */
5857 	if (mddev->pers->check_reshape == NULL)
5858 		return -EINVAL;
5859 	if (raid_disks <= 0 ||
5860 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
5861 		return -EINVAL;
5862 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5863 		return -EBUSY;
5864 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5865 
5866 	rv = mddev->pers->check_reshape(mddev);
5867 	if (rv < 0)
5868 		mddev->delta_disks = 0;
5869 	return rv;
5870 }
5871 
5872 
5873 /*
5874  * update_array_info is used to change the configuration of an
5875  * on-line array.
5876  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5877  * fields in the info are checked against the array.
5878  * Any differences that cannot be handled will cause an error.
5879  * Normally, only one change can be managed at a time.
5880  */
5881 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5882 {
5883 	int rv = 0;
5884 	int cnt = 0;
5885 	int state = 0;
5886 
5887 	/* calculate expected state,ignoring low bits */
5888 	if (mddev->bitmap && mddev->bitmap_info.offset)
5889 		state |= (1 << MD_SB_BITMAP_PRESENT);
5890 
5891 	if (mddev->major_version != info->major_version ||
5892 	    mddev->minor_version != info->minor_version ||
5893 /*	    mddev->patch_version != info->patch_version || */
5894 	    mddev->ctime         != info->ctime         ||
5895 	    mddev->level         != info->level         ||
5896 /*	    mddev->layout        != info->layout        || */
5897 	    !mddev->persistent	 != info->not_persistent||
5898 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5899 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5900 	    ((state^info->state) & 0xfffffe00)
5901 		)
5902 		return -EINVAL;
5903 	/* Check there is only one change */
5904 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5905 		cnt++;
5906 	if (mddev->raid_disks != info->raid_disks)
5907 		cnt++;
5908 	if (mddev->layout != info->layout)
5909 		cnt++;
5910 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5911 		cnt++;
5912 	if (cnt == 0)
5913 		return 0;
5914 	if (cnt > 1)
5915 		return -EINVAL;
5916 
5917 	if (mddev->layout != info->layout) {
5918 		/* Change layout
5919 		 * we don't need to do anything at the md level, the
5920 		 * personality will take care of it all.
5921 		 */
5922 		if (mddev->pers->check_reshape == NULL)
5923 			return -EINVAL;
5924 		else {
5925 			mddev->new_layout = info->layout;
5926 			rv = mddev->pers->check_reshape(mddev);
5927 			if (rv)
5928 				mddev->new_layout = mddev->layout;
5929 			return rv;
5930 		}
5931 	}
5932 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5933 		rv = update_size(mddev, (sector_t)info->size * 2);
5934 
5935 	if (mddev->raid_disks    != info->raid_disks)
5936 		rv = update_raid_disks(mddev, info->raid_disks);
5937 
5938 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5939 		if (mddev->pers->quiesce == NULL)
5940 			return -EINVAL;
5941 		if (mddev->recovery || mddev->sync_thread)
5942 			return -EBUSY;
5943 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5944 			/* add the bitmap */
5945 			if (mddev->bitmap)
5946 				return -EEXIST;
5947 			if (mddev->bitmap_info.default_offset == 0)
5948 				return -EINVAL;
5949 			mddev->bitmap_info.offset =
5950 				mddev->bitmap_info.default_offset;
5951 			mddev->pers->quiesce(mddev, 1);
5952 			rv = bitmap_create(mddev);
5953 			if (!rv)
5954 				rv = bitmap_load(mddev);
5955 			if (rv)
5956 				bitmap_destroy(mddev);
5957 			mddev->pers->quiesce(mddev, 0);
5958 		} else {
5959 			/* remove the bitmap */
5960 			if (!mddev->bitmap)
5961 				return -ENOENT;
5962 			if (mddev->bitmap->file)
5963 				return -EINVAL;
5964 			mddev->pers->quiesce(mddev, 1);
5965 			bitmap_destroy(mddev);
5966 			mddev->pers->quiesce(mddev, 0);
5967 			mddev->bitmap_info.offset = 0;
5968 		}
5969 	}
5970 	md_update_sb(mddev, 1);
5971 	return rv;
5972 }
5973 
5974 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5975 {
5976 	mdk_rdev_t *rdev;
5977 
5978 	if (mddev->pers == NULL)
5979 		return -ENODEV;
5980 
5981 	rdev = find_rdev(mddev, dev);
5982 	if (!rdev)
5983 		return -ENODEV;
5984 
5985 	md_error(mddev, rdev);
5986 	return 0;
5987 }
5988 
5989 /*
5990  * We have a problem here : there is no easy way to give a CHS
5991  * virtual geometry. We currently pretend that we have a 2 heads
5992  * 4 sectors (with a BIG number of cylinders...). This drives
5993  * dosfs just mad... ;-)
5994  */
5995 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
5996 {
5997 	mddev_t *mddev = bdev->bd_disk->private_data;
5998 
5999 	geo->heads = 2;
6000 	geo->sectors = 4;
6001 	geo->cylinders = mddev->array_sectors / 8;
6002 	return 0;
6003 }
6004 
6005 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6006 			unsigned int cmd, unsigned long arg)
6007 {
6008 	int err = 0;
6009 	void __user *argp = (void __user *)arg;
6010 	mddev_t *mddev = NULL;
6011 	int ro;
6012 
6013 	if (!capable(CAP_SYS_ADMIN))
6014 		return -EACCES;
6015 
6016 	/*
6017 	 * Commands dealing with the RAID driver but not any
6018 	 * particular array:
6019 	 */
6020 	switch (cmd)
6021 	{
6022 		case RAID_VERSION:
6023 			err = get_version(argp);
6024 			goto done;
6025 
6026 		case PRINT_RAID_DEBUG:
6027 			err = 0;
6028 			md_print_devices();
6029 			goto done;
6030 
6031 #ifndef MODULE
6032 		case RAID_AUTORUN:
6033 			err = 0;
6034 			autostart_arrays(arg);
6035 			goto done;
6036 #endif
6037 		default:;
6038 	}
6039 
6040 	/*
6041 	 * Commands creating/starting a new array:
6042 	 */
6043 
6044 	mddev = bdev->bd_disk->private_data;
6045 
6046 	if (!mddev) {
6047 		BUG();
6048 		goto abort;
6049 	}
6050 
6051 	err = mddev_lock(mddev);
6052 	if (err) {
6053 		printk(KERN_INFO
6054 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
6055 			err, cmd);
6056 		goto abort;
6057 	}
6058 
6059 	switch (cmd)
6060 	{
6061 		case SET_ARRAY_INFO:
6062 			{
6063 				mdu_array_info_t info;
6064 				if (!arg)
6065 					memset(&info, 0, sizeof(info));
6066 				else if (copy_from_user(&info, argp, sizeof(info))) {
6067 					err = -EFAULT;
6068 					goto abort_unlock;
6069 				}
6070 				if (mddev->pers) {
6071 					err = update_array_info(mddev, &info);
6072 					if (err) {
6073 						printk(KERN_WARNING "md: couldn't update"
6074 						       " array info. %d\n", err);
6075 						goto abort_unlock;
6076 					}
6077 					goto done_unlock;
6078 				}
6079 				if (!list_empty(&mddev->disks)) {
6080 					printk(KERN_WARNING
6081 					       "md: array %s already has disks!\n",
6082 					       mdname(mddev));
6083 					err = -EBUSY;
6084 					goto abort_unlock;
6085 				}
6086 				if (mddev->raid_disks) {
6087 					printk(KERN_WARNING
6088 					       "md: array %s already initialised!\n",
6089 					       mdname(mddev));
6090 					err = -EBUSY;
6091 					goto abort_unlock;
6092 				}
6093 				err = set_array_info(mddev, &info);
6094 				if (err) {
6095 					printk(KERN_WARNING "md: couldn't set"
6096 					       " array info. %d\n", err);
6097 					goto abort_unlock;
6098 				}
6099 			}
6100 			goto done_unlock;
6101 
6102 		default:;
6103 	}
6104 
6105 	/*
6106 	 * Commands querying/configuring an existing array:
6107 	 */
6108 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6109 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6110 	if ((!mddev->raid_disks && !mddev->external)
6111 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6112 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6113 	    && cmd != GET_BITMAP_FILE) {
6114 		err = -ENODEV;
6115 		goto abort_unlock;
6116 	}
6117 
6118 	/*
6119 	 * Commands even a read-only array can execute:
6120 	 */
6121 	switch (cmd)
6122 	{
6123 		case GET_ARRAY_INFO:
6124 			err = get_array_info(mddev, argp);
6125 			goto done_unlock;
6126 
6127 		case GET_BITMAP_FILE:
6128 			err = get_bitmap_file(mddev, argp);
6129 			goto done_unlock;
6130 
6131 		case GET_DISK_INFO:
6132 			err = get_disk_info(mddev, argp);
6133 			goto done_unlock;
6134 
6135 		case RESTART_ARRAY_RW:
6136 			err = restart_array(mddev);
6137 			goto done_unlock;
6138 
6139 		case STOP_ARRAY:
6140 			err = do_md_stop(mddev, 0, 1);
6141 			goto done_unlock;
6142 
6143 		case STOP_ARRAY_RO:
6144 			err = md_set_readonly(mddev, 1);
6145 			goto done_unlock;
6146 
6147 		case BLKROSET:
6148 			if (get_user(ro, (int __user *)(arg))) {
6149 				err = -EFAULT;
6150 				goto done_unlock;
6151 			}
6152 			err = -EINVAL;
6153 
6154 			/* if the bdev is going readonly the value of mddev->ro
6155 			 * does not matter, no writes are coming
6156 			 */
6157 			if (ro)
6158 				goto done_unlock;
6159 
6160 			/* are we are already prepared for writes? */
6161 			if (mddev->ro != 1)
6162 				goto done_unlock;
6163 
6164 			/* transitioning to readauto need only happen for
6165 			 * arrays that call md_write_start
6166 			 */
6167 			if (mddev->pers) {
6168 				err = restart_array(mddev);
6169 				if (err == 0) {
6170 					mddev->ro = 2;
6171 					set_disk_ro(mddev->gendisk, 0);
6172 				}
6173 			}
6174 			goto done_unlock;
6175 	}
6176 
6177 	/*
6178 	 * The remaining ioctls are changing the state of the
6179 	 * superblock, so we do not allow them on read-only arrays.
6180 	 * However non-MD ioctls (e.g. get-size) will still come through
6181 	 * here and hit the 'default' below, so only disallow
6182 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
6183 	 */
6184 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6185 		if (mddev->ro == 2) {
6186 			mddev->ro = 0;
6187 			sysfs_notify_dirent_safe(mddev->sysfs_state);
6188 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6189 			md_wakeup_thread(mddev->thread);
6190 		} else {
6191 			err = -EROFS;
6192 			goto abort_unlock;
6193 		}
6194 	}
6195 
6196 	switch (cmd)
6197 	{
6198 		case ADD_NEW_DISK:
6199 		{
6200 			mdu_disk_info_t info;
6201 			if (copy_from_user(&info, argp, sizeof(info)))
6202 				err = -EFAULT;
6203 			else
6204 				err = add_new_disk(mddev, &info);
6205 			goto done_unlock;
6206 		}
6207 
6208 		case HOT_REMOVE_DISK:
6209 			err = hot_remove_disk(mddev, new_decode_dev(arg));
6210 			goto done_unlock;
6211 
6212 		case HOT_ADD_DISK:
6213 			err = hot_add_disk(mddev, new_decode_dev(arg));
6214 			goto done_unlock;
6215 
6216 		case SET_DISK_FAULTY:
6217 			err = set_disk_faulty(mddev, new_decode_dev(arg));
6218 			goto done_unlock;
6219 
6220 		case RUN_ARRAY:
6221 			err = do_md_run(mddev);
6222 			goto done_unlock;
6223 
6224 		case SET_BITMAP_FILE:
6225 			err = set_bitmap_file(mddev, (int)arg);
6226 			goto done_unlock;
6227 
6228 		default:
6229 			err = -EINVAL;
6230 			goto abort_unlock;
6231 	}
6232 
6233 done_unlock:
6234 abort_unlock:
6235 	if (mddev->hold_active == UNTIL_IOCTL &&
6236 	    err != -EINVAL)
6237 		mddev->hold_active = 0;
6238 	mddev_unlock(mddev);
6239 
6240 	return err;
6241 done:
6242 	if (err)
6243 		MD_BUG();
6244 abort:
6245 	return err;
6246 }
6247 #ifdef CONFIG_COMPAT
6248 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6249 		    unsigned int cmd, unsigned long arg)
6250 {
6251 	switch (cmd) {
6252 	case HOT_REMOVE_DISK:
6253 	case HOT_ADD_DISK:
6254 	case SET_DISK_FAULTY:
6255 	case SET_BITMAP_FILE:
6256 		/* These take in integer arg, do not convert */
6257 		break;
6258 	default:
6259 		arg = (unsigned long)compat_ptr(arg);
6260 		break;
6261 	}
6262 
6263 	return md_ioctl(bdev, mode, cmd, arg);
6264 }
6265 #endif /* CONFIG_COMPAT */
6266 
6267 static int md_open(struct block_device *bdev, fmode_t mode)
6268 {
6269 	/*
6270 	 * Succeed if we can lock the mddev, which confirms that
6271 	 * it isn't being stopped right now.
6272 	 */
6273 	mddev_t *mddev = mddev_find(bdev->bd_dev);
6274 	int err;
6275 
6276 	if (mddev->gendisk != bdev->bd_disk) {
6277 		/* we are racing with mddev_put which is discarding this
6278 		 * bd_disk.
6279 		 */
6280 		mddev_put(mddev);
6281 		/* Wait until bdev->bd_disk is definitely gone */
6282 		flush_workqueue(md_misc_wq);
6283 		/* Then retry the open from the top */
6284 		return -ERESTARTSYS;
6285 	}
6286 	BUG_ON(mddev != bdev->bd_disk->private_data);
6287 
6288 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6289 		goto out;
6290 
6291 	err = 0;
6292 	atomic_inc(&mddev->openers);
6293 	mutex_unlock(&mddev->open_mutex);
6294 
6295 	check_disk_change(bdev);
6296  out:
6297 	return err;
6298 }
6299 
6300 static int md_release(struct gendisk *disk, fmode_t mode)
6301 {
6302  	mddev_t *mddev = disk->private_data;
6303 
6304 	BUG_ON(!mddev);
6305 	atomic_dec(&mddev->openers);
6306 	mddev_put(mddev);
6307 
6308 	return 0;
6309 }
6310 
6311 static int md_media_changed(struct gendisk *disk)
6312 {
6313 	mddev_t *mddev = disk->private_data;
6314 
6315 	return mddev->changed;
6316 }
6317 
6318 static int md_revalidate(struct gendisk *disk)
6319 {
6320 	mddev_t *mddev = disk->private_data;
6321 
6322 	mddev->changed = 0;
6323 	return 0;
6324 }
6325 static const struct block_device_operations md_fops =
6326 {
6327 	.owner		= THIS_MODULE,
6328 	.open		= md_open,
6329 	.release	= md_release,
6330 	.ioctl		= md_ioctl,
6331 #ifdef CONFIG_COMPAT
6332 	.compat_ioctl	= md_compat_ioctl,
6333 #endif
6334 	.getgeo		= md_getgeo,
6335 	.media_changed  = md_media_changed,
6336 	.revalidate_disk= md_revalidate,
6337 };
6338 
6339 static int md_thread(void * arg)
6340 {
6341 	mdk_thread_t *thread = arg;
6342 
6343 	/*
6344 	 * md_thread is a 'system-thread', it's priority should be very
6345 	 * high. We avoid resource deadlocks individually in each
6346 	 * raid personality. (RAID5 does preallocation) We also use RR and
6347 	 * the very same RT priority as kswapd, thus we will never get
6348 	 * into a priority inversion deadlock.
6349 	 *
6350 	 * we definitely have to have equal or higher priority than
6351 	 * bdflush, otherwise bdflush will deadlock if there are too
6352 	 * many dirty RAID5 blocks.
6353 	 */
6354 
6355 	allow_signal(SIGKILL);
6356 	while (!kthread_should_stop()) {
6357 
6358 		/* We need to wait INTERRUPTIBLE so that
6359 		 * we don't add to the load-average.
6360 		 * That means we need to be sure no signals are
6361 		 * pending
6362 		 */
6363 		if (signal_pending(current))
6364 			flush_signals(current);
6365 
6366 		wait_event_interruptible_timeout
6367 			(thread->wqueue,
6368 			 test_bit(THREAD_WAKEUP, &thread->flags)
6369 			 || kthread_should_stop(),
6370 			 thread->timeout);
6371 
6372 		clear_bit(THREAD_WAKEUP, &thread->flags);
6373 		if (!kthread_should_stop())
6374 			thread->run(thread->mddev);
6375 	}
6376 
6377 	return 0;
6378 }
6379 
6380 void md_wakeup_thread(mdk_thread_t *thread)
6381 {
6382 	if (thread) {
6383 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
6384 		set_bit(THREAD_WAKEUP, &thread->flags);
6385 		wake_up(&thread->wqueue);
6386 	}
6387 }
6388 
6389 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
6390 				 const char *name)
6391 {
6392 	mdk_thread_t *thread;
6393 
6394 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
6395 	if (!thread)
6396 		return NULL;
6397 
6398 	init_waitqueue_head(&thread->wqueue);
6399 
6400 	thread->run = run;
6401 	thread->mddev = mddev;
6402 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6403 	thread->tsk = kthread_run(md_thread, thread,
6404 				  "%s_%s",
6405 				  mdname(thread->mddev),
6406 				  name ?: mddev->pers->name);
6407 	if (IS_ERR(thread->tsk)) {
6408 		kfree(thread);
6409 		return NULL;
6410 	}
6411 	return thread;
6412 }
6413 
6414 void md_unregister_thread(mdk_thread_t *thread)
6415 {
6416 	if (!thread)
6417 		return;
6418 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6419 
6420 	kthread_stop(thread->tsk);
6421 	kfree(thread);
6422 }
6423 
6424 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
6425 {
6426 	if (!mddev) {
6427 		MD_BUG();
6428 		return;
6429 	}
6430 
6431 	if (!rdev || test_bit(Faulty, &rdev->flags))
6432 		return;
6433 
6434 	if (!mddev->pers || !mddev->pers->error_handler)
6435 		return;
6436 	mddev->pers->error_handler(mddev,rdev);
6437 	if (mddev->degraded)
6438 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6439 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6440 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6441 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6442 	md_wakeup_thread(mddev->thread);
6443 	if (mddev->event_work.func)
6444 		queue_work(md_misc_wq, &mddev->event_work);
6445 	md_new_event_inintr(mddev);
6446 }
6447 
6448 /* seq_file implementation /proc/mdstat */
6449 
6450 static void status_unused(struct seq_file *seq)
6451 {
6452 	int i = 0;
6453 	mdk_rdev_t *rdev;
6454 
6455 	seq_printf(seq, "unused devices: ");
6456 
6457 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6458 		char b[BDEVNAME_SIZE];
6459 		i++;
6460 		seq_printf(seq, "%s ",
6461 			      bdevname(rdev->bdev,b));
6462 	}
6463 	if (!i)
6464 		seq_printf(seq, "<none>");
6465 
6466 	seq_printf(seq, "\n");
6467 }
6468 
6469 
6470 static void status_resync(struct seq_file *seq, mddev_t * mddev)
6471 {
6472 	sector_t max_sectors, resync, res;
6473 	unsigned long dt, db;
6474 	sector_t rt;
6475 	int scale;
6476 	unsigned int per_milli;
6477 
6478 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6479 
6480 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6481 		max_sectors = mddev->resync_max_sectors;
6482 	else
6483 		max_sectors = mddev->dev_sectors;
6484 
6485 	/*
6486 	 * Should not happen.
6487 	 */
6488 	if (!max_sectors) {
6489 		MD_BUG();
6490 		return;
6491 	}
6492 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6493 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6494 	 * u32, as those are the requirements for sector_div.
6495 	 * Thus 'scale' must be at least 10
6496 	 */
6497 	scale = 10;
6498 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6499 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6500 			scale++;
6501 	}
6502 	res = (resync>>scale)*1000;
6503 	sector_div(res, (u32)((max_sectors>>scale)+1));
6504 
6505 	per_milli = res;
6506 	{
6507 		int i, x = per_milli/50, y = 20-x;
6508 		seq_printf(seq, "[");
6509 		for (i = 0; i < x; i++)
6510 			seq_printf(seq, "=");
6511 		seq_printf(seq, ">");
6512 		for (i = 0; i < y; i++)
6513 			seq_printf(seq, ".");
6514 		seq_printf(seq, "] ");
6515 	}
6516 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6517 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6518 		    "reshape" :
6519 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6520 		     "check" :
6521 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6522 		      "resync" : "recovery"))),
6523 		   per_milli/10, per_milli % 10,
6524 		   (unsigned long long) resync/2,
6525 		   (unsigned long long) max_sectors/2);
6526 
6527 	/*
6528 	 * dt: time from mark until now
6529 	 * db: blocks written from mark until now
6530 	 * rt: remaining time
6531 	 *
6532 	 * rt is a sector_t, so could be 32bit or 64bit.
6533 	 * So we divide before multiply in case it is 32bit and close
6534 	 * to the limit.
6535 	 * We scale the divisor (db) by 32 to avoid losing precision
6536 	 * near the end of resync when the number of remaining sectors
6537 	 * is close to 'db'.
6538 	 * We then divide rt by 32 after multiplying by db to compensate.
6539 	 * The '+1' avoids division by zero if db is very small.
6540 	 */
6541 	dt = ((jiffies - mddev->resync_mark) / HZ);
6542 	if (!dt) dt++;
6543 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6544 		- mddev->resync_mark_cnt;
6545 
6546 	rt = max_sectors - resync;    /* number of remaining sectors */
6547 	sector_div(rt, db/32+1);
6548 	rt *= dt;
6549 	rt >>= 5;
6550 
6551 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6552 		   ((unsigned long)rt % 60)/6);
6553 
6554 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6555 }
6556 
6557 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6558 {
6559 	struct list_head *tmp;
6560 	loff_t l = *pos;
6561 	mddev_t *mddev;
6562 
6563 	if (l >= 0x10000)
6564 		return NULL;
6565 	if (!l--)
6566 		/* header */
6567 		return (void*)1;
6568 
6569 	spin_lock(&all_mddevs_lock);
6570 	list_for_each(tmp,&all_mddevs)
6571 		if (!l--) {
6572 			mddev = list_entry(tmp, mddev_t, all_mddevs);
6573 			mddev_get(mddev);
6574 			spin_unlock(&all_mddevs_lock);
6575 			return mddev;
6576 		}
6577 	spin_unlock(&all_mddevs_lock);
6578 	if (!l--)
6579 		return (void*)2;/* tail */
6580 	return NULL;
6581 }
6582 
6583 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6584 {
6585 	struct list_head *tmp;
6586 	mddev_t *next_mddev, *mddev = v;
6587 
6588 	++*pos;
6589 	if (v == (void*)2)
6590 		return NULL;
6591 
6592 	spin_lock(&all_mddevs_lock);
6593 	if (v == (void*)1)
6594 		tmp = all_mddevs.next;
6595 	else
6596 		tmp = mddev->all_mddevs.next;
6597 	if (tmp != &all_mddevs)
6598 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
6599 	else {
6600 		next_mddev = (void*)2;
6601 		*pos = 0x10000;
6602 	}
6603 	spin_unlock(&all_mddevs_lock);
6604 
6605 	if (v != (void*)1)
6606 		mddev_put(mddev);
6607 	return next_mddev;
6608 
6609 }
6610 
6611 static void md_seq_stop(struct seq_file *seq, void *v)
6612 {
6613 	mddev_t *mddev = v;
6614 
6615 	if (mddev && v != (void*)1 && v != (void*)2)
6616 		mddev_put(mddev);
6617 }
6618 
6619 static int md_seq_show(struct seq_file *seq, void *v)
6620 {
6621 	mddev_t *mddev = v;
6622 	sector_t sectors;
6623 	mdk_rdev_t *rdev;
6624 	struct bitmap *bitmap;
6625 
6626 	if (v == (void*)1) {
6627 		struct mdk_personality *pers;
6628 		seq_printf(seq, "Personalities : ");
6629 		spin_lock(&pers_lock);
6630 		list_for_each_entry(pers, &pers_list, list)
6631 			seq_printf(seq, "[%s] ", pers->name);
6632 
6633 		spin_unlock(&pers_lock);
6634 		seq_printf(seq, "\n");
6635 		seq->poll_event = atomic_read(&md_event_count);
6636 		return 0;
6637 	}
6638 	if (v == (void*)2) {
6639 		status_unused(seq);
6640 		return 0;
6641 	}
6642 
6643 	if (mddev_lock(mddev) < 0)
6644 		return -EINTR;
6645 
6646 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6647 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6648 						mddev->pers ? "" : "in");
6649 		if (mddev->pers) {
6650 			if (mddev->ro==1)
6651 				seq_printf(seq, " (read-only)");
6652 			if (mddev->ro==2)
6653 				seq_printf(seq, " (auto-read-only)");
6654 			seq_printf(seq, " %s", mddev->pers->name);
6655 		}
6656 
6657 		sectors = 0;
6658 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6659 			char b[BDEVNAME_SIZE];
6660 			seq_printf(seq, " %s[%d]",
6661 				bdevname(rdev->bdev,b), rdev->desc_nr);
6662 			if (test_bit(WriteMostly, &rdev->flags))
6663 				seq_printf(seq, "(W)");
6664 			if (test_bit(Faulty, &rdev->flags)) {
6665 				seq_printf(seq, "(F)");
6666 				continue;
6667 			} else if (rdev->raid_disk < 0)
6668 				seq_printf(seq, "(S)"); /* spare */
6669 			sectors += rdev->sectors;
6670 		}
6671 
6672 		if (!list_empty(&mddev->disks)) {
6673 			if (mddev->pers)
6674 				seq_printf(seq, "\n      %llu blocks",
6675 					   (unsigned long long)
6676 					   mddev->array_sectors / 2);
6677 			else
6678 				seq_printf(seq, "\n      %llu blocks",
6679 					   (unsigned long long)sectors / 2);
6680 		}
6681 		if (mddev->persistent) {
6682 			if (mddev->major_version != 0 ||
6683 			    mddev->minor_version != 90) {
6684 				seq_printf(seq," super %d.%d",
6685 					   mddev->major_version,
6686 					   mddev->minor_version);
6687 			}
6688 		} else if (mddev->external)
6689 			seq_printf(seq, " super external:%s",
6690 				   mddev->metadata_type);
6691 		else
6692 			seq_printf(seq, " super non-persistent");
6693 
6694 		if (mddev->pers) {
6695 			mddev->pers->status(seq, mddev);
6696 	 		seq_printf(seq, "\n      ");
6697 			if (mddev->pers->sync_request) {
6698 				if (mddev->curr_resync > 2) {
6699 					status_resync(seq, mddev);
6700 					seq_printf(seq, "\n      ");
6701 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
6702 					seq_printf(seq, "\tresync=DELAYED\n      ");
6703 				else if (mddev->recovery_cp < MaxSector)
6704 					seq_printf(seq, "\tresync=PENDING\n      ");
6705 			}
6706 		} else
6707 			seq_printf(seq, "\n       ");
6708 
6709 		if ((bitmap = mddev->bitmap)) {
6710 			unsigned long chunk_kb;
6711 			unsigned long flags;
6712 			spin_lock_irqsave(&bitmap->lock, flags);
6713 			chunk_kb = mddev->bitmap_info.chunksize >> 10;
6714 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
6715 				"%lu%s chunk",
6716 				bitmap->pages - bitmap->missing_pages,
6717 				bitmap->pages,
6718 				(bitmap->pages - bitmap->missing_pages)
6719 					<< (PAGE_SHIFT - 10),
6720 				chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
6721 				chunk_kb ? "KB" : "B");
6722 			if (bitmap->file) {
6723 				seq_printf(seq, ", file: ");
6724 				seq_path(seq, &bitmap->file->f_path, " \t\n");
6725 			}
6726 
6727 			seq_printf(seq, "\n");
6728 			spin_unlock_irqrestore(&bitmap->lock, flags);
6729 		}
6730 
6731 		seq_printf(seq, "\n");
6732 	}
6733 	mddev_unlock(mddev);
6734 
6735 	return 0;
6736 }
6737 
6738 static const struct seq_operations md_seq_ops = {
6739 	.start  = md_seq_start,
6740 	.next   = md_seq_next,
6741 	.stop   = md_seq_stop,
6742 	.show   = md_seq_show,
6743 };
6744 
6745 static int md_seq_open(struct inode *inode, struct file *file)
6746 {
6747 	struct seq_file *seq;
6748 	int error;
6749 
6750 	error = seq_open(file, &md_seq_ops);
6751 	if (error)
6752 		return error;
6753 
6754 	seq = file->private_data;
6755 	seq->poll_event = atomic_read(&md_event_count);
6756 	return error;
6757 }
6758 
6759 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6760 {
6761 	struct seq_file *seq = filp->private_data;
6762 	int mask;
6763 
6764 	poll_wait(filp, &md_event_waiters, wait);
6765 
6766 	/* always allow read */
6767 	mask = POLLIN | POLLRDNORM;
6768 
6769 	if (seq->poll_event != atomic_read(&md_event_count))
6770 		mask |= POLLERR | POLLPRI;
6771 	return mask;
6772 }
6773 
6774 static const struct file_operations md_seq_fops = {
6775 	.owner		= THIS_MODULE,
6776 	.open           = md_seq_open,
6777 	.read           = seq_read,
6778 	.llseek         = seq_lseek,
6779 	.release	= seq_release_private,
6780 	.poll		= mdstat_poll,
6781 };
6782 
6783 int register_md_personality(struct mdk_personality *p)
6784 {
6785 	spin_lock(&pers_lock);
6786 	list_add_tail(&p->list, &pers_list);
6787 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6788 	spin_unlock(&pers_lock);
6789 	return 0;
6790 }
6791 
6792 int unregister_md_personality(struct mdk_personality *p)
6793 {
6794 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6795 	spin_lock(&pers_lock);
6796 	list_del_init(&p->list);
6797 	spin_unlock(&pers_lock);
6798 	return 0;
6799 }
6800 
6801 static int is_mddev_idle(mddev_t *mddev, int init)
6802 {
6803 	mdk_rdev_t * rdev;
6804 	int idle;
6805 	int curr_events;
6806 
6807 	idle = 1;
6808 	rcu_read_lock();
6809 	rdev_for_each_rcu(rdev, mddev) {
6810 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6811 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6812 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6813 			      atomic_read(&disk->sync_io);
6814 		/* sync IO will cause sync_io to increase before the disk_stats
6815 		 * as sync_io is counted when a request starts, and
6816 		 * disk_stats is counted when it completes.
6817 		 * So resync activity will cause curr_events to be smaller than
6818 		 * when there was no such activity.
6819 		 * non-sync IO will cause disk_stat to increase without
6820 		 * increasing sync_io so curr_events will (eventually)
6821 		 * be larger than it was before.  Once it becomes
6822 		 * substantially larger, the test below will cause
6823 		 * the array to appear non-idle, and resync will slow
6824 		 * down.
6825 		 * If there is a lot of outstanding resync activity when
6826 		 * we set last_event to curr_events, then all that activity
6827 		 * completing might cause the array to appear non-idle
6828 		 * and resync will be slowed down even though there might
6829 		 * not have been non-resync activity.  This will only
6830 		 * happen once though.  'last_events' will soon reflect
6831 		 * the state where there is little or no outstanding
6832 		 * resync requests, and further resync activity will
6833 		 * always make curr_events less than last_events.
6834 		 *
6835 		 */
6836 		if (init || curr_events - rdev->last_events > 64) {
6837 			rdev->last_events = curr_events;
6838 			idle = 0;
6839 		}
6840 	}
6841 	rcu_read_unlock();
6842 	return idle;
6843 }
6844 
6845 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6846 {
6847 	/* another "blocks" (512byte) blocks have been synced */
6848 	atomic_sub(blocks, &mddev->recovery_active);
6849 	wake_up(&mddev->recovery_wait);
6850 	if (!ok) {
6851 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6852 		md_wakeup_thread(mddev->thread);
6853 		// stop recovery, signal do_sync ....
6854 	}
6855 }
6856 
6857 
6858 /* md_write_start(mddev, bi)
6859  * If we need to update some array metadata (e.g. 'active' flag
6860  * in superblock) before writing, schedule a superblock update
6861  * and wait for it to complete.
6862  */
6863 void md_write_start(mddev_t *mddev, struct bio *bi)
6864 {
6865 	int did_change = 0;
6866 	if (bio_data_dir(bi) != WRITE)
6867 		return;
6868 
6869 	BUG_ON(mddev->ro == 1);
6870 	if (mddev->ro == 2) {
6871 		/* need to switch to read/write */
6872 		mddev->ro = 0;
6873 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6874 		md_wakeup_thread(mddev->thread);
6875 		md_wakeup_thread(mddev->sync_thread);
6876 		did_change = 1;
6877 	}
6878 	atomic_inc(&mddev->writes_pending);
6879 	if (mddev->safemode == 1)
6880 		mddev->safemode = 0;
6881 	if (mddev->in_sync) {
6882 		spin_lock_irq(&mddev->write_lock);
6883 		if (mddev->in_sync) {
6884 			mddev->in_sync = 0;
6885 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6886 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
6887 			md_wakeup_thread(mddev->thread);
6888 			did_change = 1;
6889 		}
6890 		spin_unlock_irq(&mddev->write_lock);
6891 	}
6892 	if (did_change)
6893 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6894 	wait_event(mddev->sb_wait,
6895 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6896 }
6897 
6898 void md_write_end(mddev_t *mddev)
6899 {
6900 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6901 		if (mddev->safemode == 2)
6902 			md_wakeup_thread(mddev->thread);
6903 		else if (mddev->safemode_delay)
6904 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6905 	}
6906 }
6907 
6908 /* md_allow_write(mddev)
6909  * Calling this ensures that the array is marked 'active' so that writes
6910  * may proceed without blocking.  It is important to call this before
6911  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6912  * Must be called with mddev_lock held.
6913  *
6914  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6915  * is dropped, so return -EAGAIN after notifying userspace.
6916  */
6917 int md_allow_write(mddev_t *mddev)
6918 {
6919 	if (!mddev->pers)
6920 		return 0;
6921 	if (mddev->ro)
6922 		return 0;
6923 	if (!mddev->pers->sync_request)
6924 		return 0;
6925 
6926 	spin_lock_irq(&mddev->write_lock);
6927 	if (mddev->in_sync) {
6928 		mddev->in_sync = 0;
6929 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6930 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
6931 		if (mddev->safemode_delay &&
6932 		    mddev->safemode == 0)
6933 			mddev->safemode = 1;
6934 		spin_unlock_irq(&mddev->write_lock);
6935 		md_update_sb(mddev, 0);
6936 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6937 	} else
6938 		spin_unlock_irq(&mddev->write_lock);
6939 
6940 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
6941 		return -EAGAIN;
6942 	else
6943 		return 0;
6944 }
6945 EXPORT_SYMBOL_GPL(md_allow_write);
6946 
6947 #define SYNC_MARKS	10
6948 #define	SYNC_MARK_STEP	(3*HZ)
6949 void md_do_sync(mddev_t *mddev)
6950 {
6951 	mddev_t *mddev2;
6952 	unsigned int currspeed = 0,
6953 		 window;
6954 	sector_t max_sectors,j, io_sectors;
6955 	unsigned long mark[SYNC_MARKS];
6956 	sector_t mark_cnt[SYNC_MARKS];
6957 	int last_mark,m;
6958 	struct list_head *tmp;
6959 	sector_t last_check;
6960 	int skipped = 0;
6961 	mdk_rdev_t *rdev;
6962 	char *desc;
6963 
6964 	/* just incase thread restarts... */
6965 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6966 		return;
6967 	if (mddev->ro) /* never try to sync a read-only array */
6968 		return;
6969 
6970 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6971 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6972 			desc = "data-check";
6973 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6974 			desc = "requested-resync";
6975 		else
6976 			desc = "resync";
6977 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6978 		desc = "reshape";
6979 	else
6980 		desc = "recovery";
6981 
6982 	/* we overload curr_resync somewhat here.
6983 	 * 0 == not engaged in resync at all
6984 	 * 2 == checking that there is no conflict with another sync
6985 	 * 1 == like 2, but have yielded to allow conflicting resync to
6986 	 *		commense
6987 	 * other == active in resync - this many blocks
6988 	 *
6989 	 * Before starting a resync we must have set curr_resync to
6990 	 * 2, and then checked that every "conflicting" array has curr_resync
6991 	 * less than ours.  When we find one that is the same or higher
6992 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
6993 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
6994 	 * This will mean we have to start checking from the beginning again.
6995 	 *
6996 	 */
6997 
6998 	do {
6999 		mddev->curr_resync = 2;
7000 
7001 	try_again:
7002 		if (kthread_should_stop())
7003 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7004 
7005 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7006 			goto skip;
7007 		for_each_mddev(mddev2, tmp) {
7008 			if (mddev2 == mddev)
7009 				continue;
7010 			if (!mddev->parallel_resync
7011 			&&  mddev2->curr_resync
7012 			&&  match_mddev_units(mddev, mddev2)) {
7013 				DEFINE_WAIT(wq);
7014 				if (mddev < mddev2 && mddev->curr_resync == 2) {
7015 					/* arbitrarily yield */
7016 					mddev->curr_resync = 1;
7017 					wake_up(&resync_wait);
7018 				}
7019 				if (mddev > mddev2 && mddev->curr_resync == 1)
7020 					/* no need to wait here, we can wait the next
7021 					 * time 'round when curr_resync == 2
7022 					 */
7023 					continue;
7024 				/* We need to wait 'interruptible' so as not to
7025 				 * contribute to the load average, and not to
7026 				 * be caught by 'softlockup'
7027 				 */
7028 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7029 				if (!kthread_should_stop() &&
7030 				    mddev2->curr_resync >= mddev->curr_resync) {
7031 					printk(KERN_INFO "md: delaying %s of %s"
7032 					       " until %s has finished (they"
7033 					       " share one or more physical units)\n",
7034 					       desc, mdname(mddev), mdname(mddev2));
7035 					mddev_put(mddev2);
7036 					if (signal_pending(current))
7037 						flush_signals(current);
7038 					schedule();
7039 					finish_wait(&resync_wait, &wq);
7040 					goto try_again;
7041 				}
7042 				finish_wait(&resync_wait, &wq);
7043 			}
7044 		}
7045 	} while (mddev->curr_resync < 2);
7046 
7047 	j = 0;
7048 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7049 		/* resync follows the size requested by the personality,
7050 		 * which defaults to physical size, but can be virtual size
7051 		 */
7052 		max_sectors = mddev->resync_max_sectors;
7053 		mddev->resync_mismatches = 0;
7054 		/* we don't use the checkpoint if there's a bitmap */
7055 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7056 			j = mddev->resync_min;
7057 		else if (!mddev->bitmap)
7058 			j = mddev->recovery_cp;
7059 
7060 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7061 		max_sectors = mddev->dev_sectors;
7062 	else {
7063 		/* recovery follows the physical size of devices */
7064 		max_sectors = mddev->dev_sectors;
7065 		j = MaxSector;
7066 		rcu_read_lock();
7067 		list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
7068 			if (rdev->raid_disk >= 0 &&
7069 			    !test_bit(Faulty, &rdev->flags) &&
7070 			    !test_bit(In_sync, &rdev->flags) &&
7071 			    rdev->recovery_offset < j)
7072 				j = rdev->recovery_offset;
7073 		rcu_read_unlock();
7074 	}
7075 
7076 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7077 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7078 		" %d KB/sec/disk.\n", speed_min(mddev));
7079 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7080 	       "(but not more than %d KB/sec) for %s.\n",
7081 	       speed_max(mddev), desc);
7082 
7083 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7084 
7085 	io_sectors = 0;
7086 	for (m = 0; m < SYNC_MARKS; m++) {
7087 		mark[m] = jiffies;
7088 		mark_cnt[m] = io_sectors;
7089 	}
7090 	last_mark = 0;
7091 	mddev->resync_mark = mark[last_mark];
7092 	mddev->resync_mark_cnt = mark_cnt[last_mark];
7093 
7094 	/*
7095 	 * Tune reconstruction:
7096 	 */
7097 	window = 32*(PAGE_SIZE/512);
7098 	printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7099 		window/2, (unsigned long long)max_sectors/2);
7100 
7101 	atomic_set(&mddev->recovery_active, 0);
7102 	last_check = 0;
7103 
7104 	if (j>2) {
7105 		printk(KERN_INFO
7106 		       "md: resuming %s of %s from checkpoint.\n",
7107 		       desc, mdname(mddev));
7108 		mddev->curr_resync = j;
7109 	}
7110 	mddev->curr_resync_completed = j;
7111 
7112 	while (j < max_sectors) {
7113 		sector_t sectors;
7114 
7115 		skipped = 0;
7116 
7117 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7118 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
7119 		      (mddev->curr_resync - mddev->curr_resync_completed)
7120 		      > (max_sectors >> 4)) ||
7121 		     (j - mddev->curr_resync_completed)*2
7122 		     >= mddev->resync_max - mddev->curr_resync_completed
7123 			    )) {
7124 			/* time to update curr_resync_completed */
7125 			wait_event(mddev->recovery_wait,
7126 				   atomic_read(&mddev->recovery_active) == 0);
7127 			mddev->curr_resync_completed = j;
7128 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7129 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7130 		}
7131 
7132 		while (j >= mddev->resync_max && !kthread_should_stop()) {
7133 			/* As this condition is controlled by user-space,
7134 			 * we can block indefinitely, so use '_interruptible'
7135 			 * to avoid triggering warnings.
7136 			 */
7137 			flush_signals(current); /* just in case */
7138 			wait_event_interruptible(mddev->recovery_wait,
7139 						 mddev->resync_max > j
7140 						 || kthread_should_stop());
7141 		}
7142 
7143 		if (kthread_should_stop())
7144 			goto interrupted;
7145 
7146 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
7147 						  currspeed < speed_min(mddev));
7148 		if (sectors == 0) {
7149 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7150 			goto out;
7151 		}
7152 
7153 		if (!skipped) { /* actual IO requested */
7154 			io_sectors += sectors;
7155 			atomic_add(sectors, &mddev->recovery_active);
7156 		}
7157 
7158 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7159 			break;
7160 
7161 		j += sectors;
7162 		if (j>1) mddev->curr_resync = j;
7163 		mddev->curr_mark_cnt = io_sectors;
7164 		if (last_check == 0)
7165 			/* this is the earliest that rebuild will be
7166 			 * visible in /proc/mdstat
7167 			 */
7168 			md_new_event(mddev);
7169 
7170 		if (last_check + window > io_sectors || j == max_sectors)
7171 			continue;
7172 
7173 		last_check = io_sectors;
7174 	repeat:
7175 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
7176 			/* step marks */
7177 			int next = (last_mark+1) % SYNC_MARKS;
7178 
7179 			mddev->resync_mark = mark[next];
7180 			mddev->resync_mark_cnt = mark_cnt[next];
7181 			mark[next] = jiffies;
7182 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
7183 			last_mark = next;
7184 		}
7185 
7186 
7187 		if (kthread_should_stop())
7188 			goto interrupted;
7189 
7190 
7191 		/*
7192 		 * this loop exits only if either when we are slower than
7193 		 * the 'hard' speed limit, or the system was IO-idle for
7194 		 * a jiffy.
7195 		 * the system might be non-idle CPU-wise, but we only care
7196 		 * about not overloading the IO subsystem. (things like an
7197 		 * e2fsck being done on the RAID array should execute fast)
7198 		 */
7199 		cond_resched();
7200 
7201 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
7202 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
7203 
7204 		if (currspeed > speed_min(mddev)) {
7205 			if ((currspeed > speed_max(mddev)) ||
7206 					!is_mddev_idle(mddev, 0)) {
7207 				msleep(500);
7208 				goto repeat;
7209 			}
7210 		}
7211 	}
7212 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
7213 	/*
7214 	 * this also signals 'finished resyncing' to md_stop
7215 	 */
7216  out:
7217 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
7218 
7219 	/* tell personality that we are finished */
7220 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
7221 
7222 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
7223 	    mddev->curr_resync > 2) {
7224 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7225 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7226 				if (mddev->curr_resync >= mddev->recovery_cp) {
7227 					printk(KERN_INFO
7228 					       "md: checkpointing %s of %s.\n",
7229 					       desc, mdname(mddev));
7230 					mddev->recovery_cp = mddev->curr_resync;
7231 				}
7232 			} else
7233 				mddev->recovery_cp = MaxSector;
7234 		} else {
7235 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7236 				mddev->curr_resync = MaxSector;
7237 			rcu_read_lock();
7238 			list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
7239 				if (rdev->raid_disk >= 0 &&
7240 				    mddev->delta_disks >= 0 &&
7241 				    !test_bit(Faulty, &rdev->flags) &&
7242 				    !test_bit(In_sync, &rdev->flags) &&
7243 				    rdev->recovery_offset < mddev->curr_resync)
7244 					rdev->recovery_offset = mddev->curr_resync;
7245 			rcu_read_unlock();
7246 		}
7247 	}
7248 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
7249 
7250  skip:
7251 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7252 		/* We completed so min/max setting can be forgotten if used. */
7253 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7254 			mddev->resync_min = 0;
7255 		mddev->resync_max = MaxSector;
7256 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7257 		mddev->resync_min = mddev->curr_resync_completed;
7258 	mddev->curr_resync = 0;
7259 	wake_up(&resync_wait);
7260 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
7261 	md_wakeup_thread(mddev->thread);
7262 	return;
7263 
7264  interrupted:
7265 	/*
7266 	 * got a signal, exit.
7267 	 */
7268 	printk(KERN_INFO
7269 	       "md: md_do_sync() got signal ... exiting\n");
7270 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7271 	goto out;
7272 
7273 }
7274 EXPORT_SYMBOL_GPL(md_do_sync);
7275 
7276 static int remove_and_add_spares(mddev_t *mddev)
7277 {
7278 	mdk_rdev_t *rdev;
7279 	int spares = 0;
7280 
7281 	mddev->curr_resync_completed = 0;
7282 
7283 	list_for_each_entry(rdev, &mddev->disks, same_set)
7284 		if (rdev->raid_disk >= 0 &&
7285 		    !test_bit(Blocked, &rdev->flags) &&
7286 		    (test_bit(Faulty, &rdev->flags) ||
7287 		     ! test_bit(In_sync, &rdev->flags)) &&
7288 		    atomic_read(&rdev->nr_pending)==0) {
7289 			if (mddev->pers->hot_remove_disk(
7290 				    mddev, rdev->raid_disk)==0) {
7291 				sysfs_unlink_rdev(mddev, rdev);
7292 				rdev->raid_disk = -1;
7293 			}
7294 		}
7295 
7296 	if (mddev->degraded) {
7297 		list_for_each_entry(rdev, &mddev->disks, same_set) {
7298 			if (rdev->raid_disk >= 0 &&
7299 			    !test_bit(In_sync, &rdev->flags) &&
7300 			    !test_bit(Faulty, &rdev->flags))
7301 				spares++;
7302 			if (rdev->raid_disk < 0
7303 			    && !test_bit(Faulty, &rdev->flags)) {
7304 				rdev->recovery_offset = 0;
7305 				if (mddev->pers->
7306 				    hot_add_disk(mddev, rdev) == 0) {
7307 					if (sysfs_link_rdev(mddev, rdev))
7308 						/* failure here is OK */;
7309 					spares++;
7310 					md_new_event(mddev);
7311 					set_bit(MD_CHANGE_DEVS, &mddev->flags);
7312 				} else
7313 					break;
7314 			}
7315 		}
7316 	}
7317 	return spares;
7318 }
7319 
7320 static void reap_sync_thread(mddev_t *mddev)
7321 {
7322 	mdk_rdev_t *rdev;
7323 
7324 	/* resync has finished, collect result */
7325 	md_unregister_thread(mddev->sync_thread);
7326 	mddev->sync_thread = NULL;
7327 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7328 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7329 		/* success...*/
7330 		/* activate any spares */
7331 		if (mddev->pers->spare_active(mddev))
7332 			sysfs_notify(&mddev->kobj, NULL,
7333 				     "degraded");
7334 	}
7335 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7336 	    mddev->pers->finish_reshape)
7337 		mddev->pers->finish_reshape(mddev);
7338 	md_update_sb(mddev, 1);
7339 
7340 	/* if array is no-longer degraded, then any saved_raid_disk
7341 	 * information must be scrapped
7342 	 */
7343 	if (!mddev->degraded)
7344 		list_for_each_entry(rdev, &mddev->disks, same_set)
7345 			rdev->saved_raid_disk = -1;
7346 
7347 	clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7348 	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7349 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7350 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7351 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7352 	/* flag recovery needed just to double check */
7353 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7354 	sysfs_notify_dirent_safe(mddev->sysfs_action);
7355 	md_new_event(mddev);
7356 	if (mddev->event_work.func)
7357 		queue_work(md_misc_wq, &mddev->event_work);
7358 }
7359 
7360 /*
7361  * This routine is regularly called by all per-raid-array threads to
7362  * deal with generic issues like resync and super-block update.
7363  * Raid personalities that don't have a thread (linear/raid0) do not
7364  * need this as they never do any recovery or update the superblock.
7365  *
7366  * It does not do any resync itself, but rather "forks" off other threads
7367  * to do that as needed.
7368  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7369  * "->recovery" and create a thread at ->sync_thread.
7370  * When the thread finishes it sets MD_RECOVERY_DONE
7371  * and wakeups up this thread which will reap the thread and finish up.
7372  * This thread also removes any faulty devices (with nr_pending == 0).
7373  *
7374  * The overall approach is:
7375  *  1/ if the superblock needs updating, update it.
7376  *  2/ If a recovery thread is running, don't do anything else.
7377  *  3/ If recovery has finished, clean up, possibly marking spares active.
7378  *  4/ If there are any faulty devices, remove them.
7379  *  5/ If array is degraded, try to add spares devices
7380  *  6/ If array has spares or is not in-sync, start a resync thread.
7381  */
7382 void md_check_recovery(mddev_t *mddev)
7383 {
7384 	if (mddev->suspended)
7385 		return;
7386 
7387 	if (mddev->bitmap)
7388 		bitmap_daemon_work(mddev);
7389 
7390 	if (signal_pending(current)) {
7391 		if (mddev->pers->sync_request && !mddev->external) {
7392 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7393 			       mdname(mddev));
7394 			mddev->safemode = 2;
7395 		}
7396 		flush_signals(current);
7397 	}
7398 
7399 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7400 		return;
7401 	if ( ! (
7402 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7403 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7404 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7405 		(mddev->external == 0 && mddev->safemode == 1) ||
7406 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7407 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7408 		))
7409 		return;
7410 
7411 	if (mddev_trylock(mddev)) {
7412 		int spares = 0;
7413 
7414 		if (mddev->ro) {
7415 			/* Only thing we do on a ro array is remove
7416 			 * failed devices.
7417 			 */
7418 			mdk_rdev_t *rdev;
7419 			list_for_each_entry(rdev, &mddev->disks, same_set)
7420 				if (rdev->raid_disk >= 0 &&
7421 				    !test_bit(Blocked, &rdev->flags) &&
7422 				    test_bit(Faulty, &rdev->flags) &&
7423 				    atomic_read(&rdev->nr_pending)==0) {
7424 					if (mddev->pers->hot_remove_disk(
7425 						    mddev, rdev->raid_disk)==0) {
7426 						sysfs_unlink_rdev(mddev, rdev);
7427 						rdev->raid_disk = -1;
7428 					}
7429 				}
7430 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7431 			goto unlock;
7432 		}
7433 
7434 		if (!mddev->external) {
7435 			int did_change = 0;
7436 			spin_lock_irq(&mddev->write_lock);
7437 			if (mddev->safemode &&
7438 			    !atomic_read(&mddev->writes_pending) &&
7439 			    !mddev->in_sync &&
7440 			    mddev->recovery_cp == MaxSector) {
7441 				mddev->in_sync = 1;
7442 				did_change = 1;
7443 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7444 			}
7445 			if (mddev->safemode == 1)
7446 				mddev->safemode = 0;
7447 			spin_unlock_irq(&mddev->write_lock);
7448 			if (did_change)
7449 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7450 		}
7451 
7452 		if (mddev->flags)
7453 			md_update_sb(mddev, 0);
7454 
7455 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7456 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7457 			/* resync/recovery still happening */
7458 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7459 			goto unlock;
7460 		}
7461 		if (mddev->sync_thread) {
7462 			reap_sync_thread(mddev);
7463 			goto unlock;
7464 		}
7465 		/* Set RUNNING before clearing NEEDED to avoid
7466 		 * any transients in the value of "sync_action".
7467 		 */
7468 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7469 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7470 		/* Clear some bits that don't mean anything, but
7471 		 * might be left set
7472 		 */
7473 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7474 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7475 
7476 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7477 			goto unlock;
7478 		/* no recovery is running.
7479 		 * remove any failed drives, then
7480 		 * add spares if possible.
7481 		 * Spare are also removed and re-added, to allow
7482 		 * the personality to fail the re-add.
7483 		 */
7484 
7485 		if (mddev->reshape_position != MaxSector) {
7486 			if (mddev->pers->check_reshape == NULL ||
7487 			    mddev->pers->check_reshape(mddev) != 0)
7488 				/* Cannot proceed */
7489 				goto unlock;
7490 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7491 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7492 		} else if ((spares = remove_and_add_spares(mddev))) {
7493 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7494 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7495 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7496 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7497 		} else if (mddev->recovery_cp < MaxSector) {
7498 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7499 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7500 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7501 			/* nothing to be done ... */
7502 			goto unlock;
7503 
7504 		if (mddev->pers->sync_request) {
7505 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
7506 				/* We are adding a device or devices to an array
7507 				 * which has the bitmap stored on all devices.
7508 				 * So make sure all bitmap pages get written
7509 				 */
7510 				bitmap_write_all(mddev->bitmap);
7511 			}
7512 			mddev->sync_thread = md_register_thread(md_do_sync,
7513 								mddev,
7514 								"resync");
7515 			if (!mddev->sync_thread) {
7516 				printk(KERN_ERR "%s: could not start resync"
7517 					" thread...\n",
7518 					mdname(mddev));
7519 				/* leave the spares where they are, it shouldn't hurt */
7520 				clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7521 				clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7522 				clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7523 				clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7524 				clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7525 			} else
7526 				md_wakeup_thread(mddev->sync_thread);
7527 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7528 			md_new_event(mddev);
7529 		}
7530 	unlock:
7531 		if (!mddev->sync_thread) {
7532 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7533 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7534 					       &mddev->recovery))
7535 				if (mddev->sysfs_action)
7536 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7537 		}
7538 		mddev_unlock(mddev);
7539 	}
7540 }
7541 
7542 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
7543 {
7544 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7545 	wait_event_timeout(rdev->blocked_wait,
7546 			   !test_bit(Blocked, &rdev->flags) &&
7547 			   !test_bit(BlockedBadBlocks, &rdev->flags),
7548 			   msecs_to_jiffies(5000));
7549 	rdev_dec_pending(rdev, mddev);
7550 }
7551 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7552 
7553 
7554 /* Bad block management.
7555  * We can record which blocks on each device are 'bad' and so just
7556  * fail those blocks, or that stripe, rather than the whole device.
7557  * Entries in the bad-block table are 64bits wide.  This comprises:
7558  * Length of bad-range, in sectors: 0-511 for lengths 1-512
7559  * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
7560  *  A 'shift' can be set so that larger blocks are tracked and
7561  *  consequently larger devices can be covered.
7562  * 'Acknowledged' flag - 1 bit. - the most significant bit.
7563  *
7564  * Locking of the bad-block table uses a seqlock so md_is_badblock
7565  * might need to retry if it is very unlucky.
7566  * We will sometimes want to check for bad blocks in a bi_end_io function,
7567  * so we use the write_seqlock_irq variant.
7568  *
7569  * When looking for a bad block we specify a range and want to
7570  * know if any block in the range is bad.  So we binary-search
7571  * to the last range that starts at-or-before the given endpoint,
7572  * (or "before the sector after the target range")
7573  * then see if it ends after the given start.
7574  * We return
7575  *  0 if there are no known bad blocks in the range
7576  *  1 if there are known bad block which are all acknowledged
7577  * -1 if there are bad blocks which have not yet been acknowledged in metadata.
7578  * plus the start/length of the first bad section we overlap.
7579  */
7580 int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
7581 		   sector_t *first_bad, int *bad_sectors)
7582 {
7583 	int hi;
7584 	int lo = 0;
7585 	u64 *p = bb->page;
7586 	int rv = 0;
7587 	sector_t target = s + sectors;
7588 	unsigned seq;
7589 
7590 	if (bb->shift > 0) {
7591 		/* round the start down, and the end up */
7592 		s >>= bb->shift;
7593 		target += (1<<bb->shift) - 1;
7594 		target >>= bb->shift;
7595 		sectors = target - s;
7596 	}
7597 	/* 'target' is now the first block after the bad range */
7598 
7599 retry:
7600 	seq = read_seqbegin(&bb->lock);
7601 
7602 	hi = bb->count;
7603 
7604 	/* Binary search between lo and hi for 'target'
7605 	 * i.e. for the last range that starts before 'target'
7606 	 */
7607 	/* INVARIANT: ranges before 'lo' and at-or-after 'hi'
7608 	 * are known not to be the last range before target.
7609 	 * VARIANT: hi-lo is the number of possible
7610 	 * ranges, and decreases until it reaches 1
7611 	 */
7612 	while (hi - lo > 1) {
7613 		int mid = (lo + hi) / 2;
7614 		sector_t a = BB_OFFSET(p[mid]);
7615 		if (a < target)
7616 			/* This could still be the one, earlier ranges
7617 			 * could not. */
7618 			lo = mid;
7619 		else
7620 			/* This and later ranges are definitely out. */
7621 			hi = mid;
7622 	}
7623 	/* 'lo' might be the last that started before target, but 'hi' isn't */
7624 	if (hi > lo) {
7625 		/* need to check all range that end after 's' to see if
7626 		 * any are unacknowledged.
7627 		 */
7628 		while (lo >= 0 &&
7629 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7630 			if (BB_OFFSET(p[lo]) < target) {
7631 				/* starts before the end, and finishes after
7632 				 * the start, so they must overlap
7633 				 */
7634 				if (rv != -1 && BB_ACK(p[lo]))
7635 					rv = 1;
7636 				else
7637 					rv = -1;
7638 				*first_bad = BB_OFFSET(p[lo]);
7639 				*bad_sectors = BB_LEN(p[lo]);
7640 			}
7641 			lo--;
7642 		}
7643 	}
7644 
7645 	if (read_seqretry(&bb->lock, seq))
7646 		goto retry;
7647 
7648 	return rv;
7649 }
7650 EXPORT_SYMBOL_GPL(md_is_badblock);
7651 
7652 /*
7653  * Add a range of bad blocks to the table.
7654  * This might extend the table, or might contract it
7655  * if two adjacent ranges can be merged.
7656  * We binary-search to find the 'insertion' point, then
7657  * decide how best to handle it.
7658  */
7659 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
7660 			    int acknowledged)
7661 {
7662 	u64 *p;
7663 	int lo, hi;
7664 	int rv = 1;
7665 
7666 	if (bb->shift < 0)
7667 		/* badblocks are disabled */
7668 		return 0;
7669 
7670 	if (bb->shift) {
7671 		/* round the start down, and the end up */
7672 		sector_t next = s + sectors;
7673 		s >>= bb->shift;
7674 		next += (1<<bb->shift) - 1;
7675 		next >>= bb->shift;
7676 		sectors = next - s;
7677 	}
7678 
7679 	write_seqlock_irq(&bb->lock);
7680 
7681 	p = bb->page;
7682 	lo = 0;
7683 	hi = bb->count;
7684 	/* Find the last range that starts at-or-before 's' */
7685 	while (hi - lo > 1) {
7686 		int mid = (lo + hi) / 2;
7687 		sector_t a = BB_OFFSET(p[mid]);
7688 		if (a <= s)
7689 			lo = mid;
7690 		else
7691 			hi = mid;
7692 	}
7693 	if (hi > lo && BB_OFFSET(p[lo]) > s)
7694 		hi = lo;
7695 
7696 	if (hi > lo) {
7697 		/* we found a range that might merge with the start
7698 		 * of our new range
7699 		 */
7700 		sector_t a = BB_OFFSET(p[lo]);
7701 		sector_t e = a + BB_LEN(p[lo]);
7702 		int ack = BB_ACK(p[lo]);
7703 		if (e >= s) {
7704 			/* Yes, we can merge with a previous range */
7705 			if (s == a && s + sectors >= e)
7706 				/* new range covers old */
7707 				ack = acknowledged;
7708 			else
7709 				ack = ack && acknowledged;
7710 
7711 			if (e < s + sectors)
7712 				e = s + sectors;
7713 			if (e - a <= BB_MAX_LEN) {
7714 				p[lo] = BB_MAKE(a, e-a, ack);
7715 				s = e;
7716 			} else {
7717 				/* does not all fit in one range,
7718 				 * make p[lo] maximal
7719 				 */
7720 				if (BB_LEN(p[lo]) != BB_MAX_LEN)
7721 					p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
7722 				s = a + BB_MAX_LEN;
7723 			}
7724 			sectors = e - s;
7725 		}
7726 	}
7727 	if (sectors && hi < bb->count) {
7728 		/* 'hi' points to the first range that starts after 's'.
7729 		 * Maybe we can merge with the start of that range */
7730 		sector_t a = BB_OFFSET(p[hi]);
7731 		sector_t e = a + BB_LEN(p[hi]);
7732 		int ack = BB_ACK(p[hi]);
7733 		if (a <= s + sectors) {
7734 			/* merging is possible */
7735 			if (e <= s + sectors) {
7736 				/* full overlap */
7737 				e = s + sectors;
7738 				ack = acknowledged;
7739 			} else
7740 				ack = ack && acknowledged;
7741 
7742 			a = s;
7743 			if (e - a <= BB_MAX_LEN) {
7744 				p[hi] = BB_MAKE(a, e-a, ack);
7745 				s = e;
7746 			} else {
7747 				p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
7748 				s = a + BB_MAX_LEN;
7749 			}
7750 			sectors = e - s;
7751 			lo = hi;
7752 			hi++;
7753 		}
7754 	}
7755 	if (sectors == 0 && hi < bb->count) {
7756 		/* we might be able to combine lo and hi */
7757 		/* Note: 's' is at the end of 'lo' */
7758 		sector_t a = BB_OFFSET(p[hi]);
7759 		int lolen = BB_LEN(p[lo]);
7760 		int hilen = BB_LEN(p[hi]);
7761 		int newlen = lolen + hilen - (s - a);
7762 		if (s >= a && newlen < BB_MAX_LEN) {
7763 			/* yes, we can combine them */
7764 			int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
7765 			p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
7766 			memmove(p + hi, p + hi + 1,
7767 				(bb->count - hi - 1) * 8);
7768 			bb->count--;
7769 		}
7770 	}
7771 	while (sectors) {
7772 		/* didn't merge (it all).
7773 		 * Need to add a range just before 'hi' */
7774 		if (bb->count >= MD_MAX_BADBLOCKS) {
7775 			/* No room for more */
7776 			rv = 0;
7777 			break;
7778 		} else {
7779 			int this_sectors = sectors;
7780 			memmove(p + hi + 1, p + hi,
7781 				(bb->count - hi) * 8);
7782 			bb->count++;
7783 
7784 			if (this_sectors > BB_MAX_LEN)
7785 				this_sectors = BB_MAX_LEN;
7786 			p[hi] = BB_MAKE(s, this_sectors, acknowledged);
7787 			sectors -= this_sectors;
7788 			s += this_sectors;
7789 		}
7790 	}
7791 
7792 	bb->changed = 1;
7793 	if (!acknowledged)
7794 		bb->unacked_exist = 1;
7795 	write_sequnlock_irq(&bb->lock);
7796 
7797 	return rv;
7798 }
7799 
7800 int rdev_set_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors,
7801 		       int acknowledged)
7802 {
7803 	int rv = md_set_badblocks(&rdev->badblocks,
7804 				  s + rdev->data_offset, sectors, acknowledged);
7805 	if (rv) {
7806 		/* Make sure they get written out promptly */
7807 		set_bit(MD_CHANGE_CLEAN, &rdev->mddev->flags);
7808 		md_wakeup_thread(rdev->mddev->thread);
7809 	}
7810 	return rv;
7811 }
7812 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
7813 
7814 /*
7815  * Remove a range of bad blocks from the table.
7816  * This may involve extending the table if we spilt a region,
7817  * but it must not fail.  So if the table becomes full, we just
7818  * drop the remove request.
7819  */
7820 static int md_clear_badblocks(struct badblocks *bb, sector_t s, int sectors)
7821 {
7822 	u64 *p;
7823 	int lo, hi;
7824 	sector_t target = s + sectors;
7825 	int rv = 0;
7826 
7827 	if (bb->shift > 0) {
7828 		/* When clearing we round the start up and the end down.
7829 		 * This should not matter as the shift should align with
7830 		 * the block size and no rounding should ever be needed.
7831 		 * However it is better the think a block is bad when it
7832 		 * isn't than to think a block is not bad when it is.
7833 		 */
7834 		s += (1<<bb->shift) - 1;
7835 		s >>= bb->shift;
7836 		target >>= bb->shift;
7837 		sectors = target - s;
7838 	}
7839 
7840 	write_seqlock_irq(&bb->lock);
7841 
7842 	p = bb->page;
7843 	lo = 0;
7844 	hi = bb->count;
7845 	/* Find the last range that starts before 'target' */
7846 	while (hi - lo > 1) {
7847 		int mid = (lo + hi) / 2;
7848 		sector_t a = BB_OFFSET(p[mid]);
7849 		if (a < target)
7850 			lo = mid;
7851 		else
7852 			hi = mid;
7853 	}
7854 	if (hi > lo) {
7855 		/* p[lo] is the last range that could overlap the
7856 		 * current range.  Earlier ranges could also overlap,
7857 		 * but only this one can overlap the end of the range.
7858 		 */
7859 		if (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) {
7860 			/* Partial overlap, leave the tail of this range */
7861 			int ack = BB_ACK(p[lo]);
7862 			sector_t a = BB_OFFSET(p[lo]);
7863 			sector_t end = a + BB_LEN(p[lo]);
7864 
7865 			if (a < s) {
7866 				/* we need to split this range */
7867 				if (bb->count >= MD_MAX_BADBLOCKS) {
7868 					rv = 0;
7869 					goto out;
7870 				}
7871 				memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
7872 				bb->count++;
7873 				p[lo] = BB_MAKE(a, s-a, ack);
7874 				lo++;
7875 			}
7876 			p[lo] = BB_MAKE(target, end - target, ack);
7877 			/* there is no longer an overlap */
7878 			hi = lo;
7879 			lo--;
7880 		}
7881 		while (lo >= 0 &&
7882 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7883 			/* This range does overlap */
7884 			if (BB_OFFSET(p[lo]) < s) {
7885 				/* Keep the early parts of this range. */
7886 				int ack = BB_ACK(p[lo]);
7887 				sector_t start = BB_OFFSET(p[lo]);
7888 				p[lo] = BB_MAKE(start, s - start, ack);
7889 				/* now low doesn't overlap, so.. */
7890 				break;
7891 			}
7892 			lo--;
7893 		}
7894 		/* 'lo' is strictly before, 'hi' is strictly after,
7895 		 * anything between needs to be discarded
7896 		 */
7897 		if (hi - lo > 1) {
7898 			memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
7899 			bb->count -= (hi - lo - 1);
7900 		}
7901 	}
7902 
7903 	bb->changed = 1;
7904 out:
7905 	write_sequnlock_irq(&bb->lock);
7906 	return rv;
7907 }
7908 
7909 int rdev_clear_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors)
7910 {
7911 	return md_clear_badblocks(&rdev->badblocks,
7912 				  s + rdev->data_offset,
7913 				  sectors);
7914 }
7915 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
7916 
7917 /*
7918  * Acknowledge all bad blocks in a list.
7919  * This only succeeds if ->changed is clear.  It is used by
7920  * in-kernel metadata updates
7921  */
7922 void md_ack_all_badblocks(struct badblocks *bb)
7923 {
7924 	if (bb->page == NULL || bb->changed)
7925 		/* no point even trying */
7926 		return;
7927 	write_seqlock_irq(&bb->lock);
7928 
7929 	if (bb->changed == 0) {
7930 		u64 *p = bb->page;
7931 		int i;
7932 		for (i = 0; i < bb->count ; i++) {
7933 			if (!BB_ACK(p[i])) {
7934 				sector_t start = BB_OFFSET(p[i]);
7935 				int len = BB_LEN(p[i]);
7936 				p[i] = BB_MAKE(start, len, 1);
7937 			}
7938 		}
7939 		bb->unacked_exist = 0;
7940 	}
7941 	write_sequnlock_irq(&bb->lock);
7942 }
7943 EXPORT_SYMBOL_GPL(md_ack_all_badblocks);
7944 
7945 /* sysfs access to bad-blocks list.
7946  * We present two files.
7947  * 'bad-blocks' lists sector numbers and lengths of ranges that
7948  *    are recorded as bad.  The list is truncated to fit within
7949  *    the one-page limit of sysfs.
7950  *    Writing "sector length" to this file adds an acknowledged
7951  *    bad block list.
7952  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
7953  *    been acknowledged.  Writing to this file adds bad blocks
7954  *    without acknowledging them.  This is largely for testing.
7955  */
7956 
7957 static ssize_t
7958 badblocks_show(struct badblocks *bb, char *page, int unack)
7959 {
7960 	size_t len;
7961 	int i;
7962 	u64 *p = bb->page;
7963 	unsigned seq;
7964 
7965 	if (bb->shift < 0)
7966 		return 0;
7967 
7968 retry:
7969 	seq = read_seqbegin(&bb->lock);
7970 
7971 	len = 0;
7972 	i = 0;
7973 
7974 	while (len < PAGE_SIZE && i < bb->count) {
7975 		sector_t s = BB_OFFSET(p[i]);
7976 		unsigned int length = BB_LEN(p[i]);
7977 		int ack = BB_ACK(p[i]);
7978 		i++;
7979 
7980 		if (unack && ack)
7981 			continue;
7982 
7983 		len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
7984 				(unsigned long long)s << bb->shift,
7985 				length << bb->shift);
7986 	}
7987 	if (unack && len == 0)
7988 		bb->unacked_exist = 0;
7989 
7990 	if (read_seqretry(&bb->lock, seq))
7991 		goto retry;
7992 
7993 	return len;
7994 }
7995 
7996 #define DO_DEBUG 1
7997 
7998 static ssize_t
7999 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack)
8000 {
8001 	unsigned long long sector;
8002 	int length;
8003 	char newline;
8004 #ifdef DO_DEBUG
8005 	/* Allow clearing via sysfs *only* for testing/debugging.
8006 	 * Normally only a successful write may clear a badblock
8007 	 */
8008 	int clear = 0;
8009 	if (page[0] == '-') {
8010 		clear = 1;
8011 		page++;
8012 	}
8013 #endif /* DO_DEBUG */
8014 
8015 	switch (sscanf(page, "%llu %d%c", &sector, &length, &newline)) {
8016 	case 3:
8017 		if (newline != '\n')
8018 			return -EINVAL;
8019 	case 2:
8020 		if (length <= 0)
8021 			return -EINVAL;
8022 		break;
8023 	default:
8024 		return -EINVAL;
8025 	}
8026 
8027 #ifdef DO_DEBUG
8028 	if (clear) {
8029 		md_clear_badblocks(bb, sector, length);
8030 		return len;
8031 	}
8032 #endif /* DO_DEBUG */
8033 	if (md_set_badblocks(bb, sector, length, !unack))
8034 		return len;
8035 	else
8036 		return -ENOSPC;
8037 }
8038 
8039 static int md_notify_reboot(struct notifier_block *this,
8040 			    unsigned long code, void *x)
8041 {
8042 	struct list_head *tmp;
8043 	mddev_t *mddev;
8044 
8045 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
8046 
8047 		printk(KERN_INFO "md: stopping all md devices.\n");
8048 
8049 		for_each_mddev(mddev, tmp)
8050 			if (mddev_trylock(mddev)) {
8051 				/* Force a switch to readonly even array
8052 				 * appears to still be in use.  Hence
8053 				 * the '100'.
8054 				 */
8055 				md_set_readonly(mddev, 100);
8056 				mddev_unlock(mddev);
8057 			}
8058 		/*
8059 		 * certain more exotic SCSI devices are known to be
8060 		 * volatile wrt too early system reboots. While the
8061 		 * right place to handle this issue is the given
8062 		 * driver, we do want to have a safe RAID driver ...
8063 		 */
8064 		mdelay(1000*1);
8065 	}
8066 	return NOTIFY_DONE;
8067 }
8068 
8069 static struct notifier_block md_notifier = {
8070 	.notifier_call	= md_notify_reboot,
8071 	.next		= NULL,
8072 	.priority	= INT_MAX, /* before any real devices */
8073 };
8074 
8075 static void md_geninit(void)
8076 {
8077 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
8078 
8079 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
8080 }
8081 
8082 static int __init md_init(void)
8083 {
8084 	int ret = -ENOMEM;
8085 
8086 	md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
8087 	if (!md_wq)
8088 		goto err_wq;
8089 
8090 	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
8091 	if (!md_misc_wq)
8092 		goto err_misc_wq;
8093 
8094 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
8095 		goto err_md;
8096 
8097 	if ((ret = register_blkdev(0, "mdp")) < 0)
8098 		goto err_mdp;
8099 	mdp_major = ret;
8100 
8101 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
8102 			    md_probe, NULL, NULL);
8103 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
8104 			    md_probe, NULL, NULL);
8105 
8106 	register_reboot_notifier(&md_notifier);
8107 	raid_table_header = register_sysctl_table(raid_root_table);
8108 
8109 	md_geninit();
8110 	return 0;
8111 
8112 err_mdp:
8113 	unregister_blkdev(MD_MAJOR, "md");
8114 err_md:
8115 	destroy_workqueue(md_misc_wq);
8116 err_misc_wq:
8117 	destroy_workqueue(md_wq);
8118 err_wq:
8119 	return ret;
8120 }
8121 
8122 #ifndef MODULE
8123 
8124 /*
8125  * Searches all registered partitions for autorun RAID arrays
8126  * at boot time.
8127  */
8128 
8129 static LIST_HEAD(all_detected_devices);
8130 struct detected_devices_node {
8131 	struct list_head list;
8132 	dev_t dev;
8133 };
8134 
8135 void md_autodetect_dev(dev_t dev)
8136 {
8137 	struct detected_devices_node *node_detected_dev;
8138 
8139 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
8140 	if (node_detected_dev) {
8141 		node_detected_dev->dev = dev;
8142 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
8143 	} else {
8144 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
8145 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
8146 	}
8147 }
8148 
8149 
8150 static void autostart_arrays(int part)
8151 {
8152 	mdk_rdev_t *rdev;
8153 	struct detected_devices_node *node_detected_dev;
8154 	dev_t dev;
8155 	int i_scanned, i_passed;
8156 
8157 	i_scanned = 0;
8158 	i_passed = 0;
8159 
8160 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
8161 
8162 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
8163 		i_scanned++;
8164 		node_detected_dev = list_entry(all_detected_devices.next,
8165 					struct detected_devices_node, list);
8166 		list_del(&node_detected_dev->list);
8167 		dev = node_detected_dev->dev;
8168 		kfree(node_detected_dev);
8169 		rdev = md_import_device(dev,0, 90);
8170 		if (IS_ERR(rdev))
8171 			continue;
8172 
8173 		if (test_bit(Faulty, &rdev->flags)) {
8174 			MD_BUG();
8175 			continue;
8176 		}
8177 		set_bit(AutoDetected, &rdev->flags);
8178 		list_add(&rdev->same_set, &pending_raid_disks);
8179 		i_passed++;
8180 	}
8181 
8182 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
8183 						i_scanned, i_passed);
8184 
8185 	autorun_devices(part);
8186 }
8187 
8188 #endif /* !MODULE */
8189 
8190 static __exit void md_exit(void)
8191 {
8192 	mddev_t *mddev;
8193 	struct list_head *tmp;
8194 
8195 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
8196 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
8197 
8198 	unregister_blkdev(MD_MAJOR,"md");
8199 	unregister_blkdev(mdp_major, "mdp");
8200 	unregister_reboot_notifier(&md_notifier);
8201 	unregister_sysctl_table(raid_table_header);
8202 	remove_proc_entry("mdstat", NULL);
8203 	for_each_mddev(mddev, tmp) {
8204 		export_array(mddev);
8205 		mddev->hold_active = 0;
8206 	}
8207 	destroy_workqueue(md_misc_wq);
8208 	destroy_workqueue(md_wq);
8209 }
8210 
8211 subsys_initcall(md_init);
8212 module_exit(md_exit)
8213 
8214 static int get_ro(char *buffer, struct kernel_param *kp)
8215 {
8216 	return sprintf(buffer, "%d", start_readonly);
8217 }
8218 static int set_ro(const char *val, struct kernel_param *kp)
8219 {
8220 	char *e;
8221 	int num = simple_strtoul(val, &e, 10);
8222 	if (*val && (*e == '\0' || *e == '\n')) {
8223 		start_readonly = num;
8224 		return 0;
8225 	}
8226 	return -EINVAL;
8227 }
8228 
8229 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
8230 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
8231 
8232 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
8233 
8234 EXPORT_SYMBOL(register_md_personality);
8235 EXPORT_SYMBOL(unregister_md_personality);
8236 EXPORT_SYMBOL(md_error);
8237 EXPORT_SYMBOL(md_done_sync);
8238 EXPORT_SYMBOL(md_write_start);
8239 EXPORT_SYMBOL(md_write_end);
8240 EXPORT_SYMBOL(md_register_thread);
8241 EXPORT_SYMBOL(md_unregister_thread);
8242 EXPORT_SYMBOL(md_wakeup_thread);
8243 EXPORT_SYMBOL(md_check_recovery);
8244 MODULE_LICENSE("GPL");
8245 MODULE_DESCRIPTION("MD RAID framework");
8246 MODULE_ALIAS("md");
8247 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
8248