xref: /linux/drivers/md/md.c (revision a1741e7fcbc19a67520115df480ab17012cc3d0b)
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(WRITE_FLUSH_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 	/* Limit to 4TB as metadata cannot record more than that */
1142 	if (rdev->sectors >= (2ULL << 32))
1143 		rdev->sectors = (2ULL << 32) - 2;
1144 
1145 	if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1146 		/* "this cannot possibly happen" ... */
1147 		ret = -EINVAL;
1148 
1149  abort:
1150 	return ret;
1151 }
1152 
1153 /*
1154  * validate_super for 0.90.0
1155  */
1156 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1157 {
1158 	mdp_disk_t *desc;
1159 	mdp_super_t *sb = page_address(rdev->sb_page);
1160 	__u64 ev1 = md_event(sb);
1161 
1162 	rdev->raid_disk = -1;
1163 	clear_bit(Faulty, &rdev->flags);
1164 	clear_bit(In_sync, &rdev->flags);
1165 	clear_bit(WriteMostly, &rdev->flags);
1166 
1167 	if (mddev->raid_disks == 0) {
1168 		mddev->major_version = 0;
1169 		mddev->minor_version = sb->minor_version;
1170 		mddev->patch_version = sb->patch_version;
1171 		mddev->external = 0;
1172 		mddev->chunk_sectors = sb->chunk_size >> 9;
1173 		mddev->ctime = sb->ctime;
1174 		mddev->utime = sb->utime;
1175 		mddev->level = sb->level;
1176 		mddev->clevel[0] = 0;
1177 		mddev->layout = sb->layout;
1178 		mddev->raid_disks = sb->raid_disks;
1179 		mddev->dev_sectors = ((sector_t)sb->size) * 2;
1180 		mddev->events = ev1;
1181 		mddev->bitmap_info.offset = 0;
1182 		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1183 
1184 		if (mddev->minor_version >= 91) {
1185 			mddev->reshape_position = sb->reshape_position;
1186 			mddev->delta_disks = sb->delta_disks;
1187 			mddev->new_level = sb->new_level;
1188 			mddev->new_layout = sb->new_layout;
1189 			mddev->new_chunk_sectors = sb->new_chunk >> 9;
1190 		} else {
1191 			mddev->reshape_position = MaxSector;
1192 			mddev->delta_disks = 0;
1193 			mddev->new_level = mddev->level;
1194 			mddev->new_layout = mddev->layout;
1195 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1196 		}
1197 
1198 		if (sb->state & (1<<MD_SB_CLEAN))
1199 			mddev->recovery_cp = MaxSector;
1200 		else {
1201 			if (sb->events_hi == sb->cp_events_hi &&
1202 				sb->events_lo == sb->cp_events_lo) {
1203 				mddev->recovery_cp = sb->recovery_cp;
1204 			} else
1205 				mddev->recovery_cp = 0;
1206 		}
1207 
1208 		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1209 		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1210 		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1211 		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1212 
1213 		mddev->max_disks = MD_SB_DISKS;
1214 
1215 		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1216 		    mddev->bitmap_info.file == NULL)
1217 			mddev->bitmap_info.offset =
1218 				mddev->bitmap_info.default_offset;
1219 
1220 	} else if (mddev->pers == NULL) {
1221 		/* Insist on good event counter while assembling, except
1222 		 * for spares (which don't need an event count) */
1223 		++ev1;
1224 		if (sb->disks[rdev->desc_nr].state & (
1225 			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1226 			if (ev1 < mddev->events)
1227 				return -EINVAL;
1228 	} else if (mddev->bitmap) {
1229 		/* if adding to array with a bitmap, then we can accept an
1230 		 * older device ... but not too old.
1231 		 */
1232 		if (ev1 < mddev->bitmap->events_cleared)
1233 			return 0;
1234 	} else {
1235 		if (ev1 < mddev->events)
1236 			/* just a hot-add of a new device, leave raid_disk at -1 */
1237 			return 0;
1238 	}
1239 
1240 	if (mddev->level != LEVEL_MULTIPATH) {
1241 		desc = sb->disks + rdev->desc_nr;
1242 
1243 		if (desc->state & (1<<MD_DISK_FAULTY))
1244 			set_bit(Faulty, &rdev->flags);
1245 		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1246 			    desc->raid_disk < mddev->raid_disks */) {
1247 			set_bit(In_sync, &rdev->flags);
1248 			rdev->raid_disk = desc->raid_disk;
1249 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1250 			/* active but not in sync implies recovery up to
1251 			 * reshape position.  We don't know exactly where
1252 			 * that is, so set to zero for now */
1253 			if (mddev->minor_version >= 91) {
1254 				rdev->recovery_offset = 0;
1255 				rdev->raid_disk = desc->raid_disk;
1256 			}
1257 		}
1258 		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1259 			set_bit(WriteMostly, &rdev->flags);
1260 	} else /* MULTIPATH are always insync */
1261 		set_bit(In_sync, &rdev->flags);
1262 	return 0;
1263 }
1264 
1265 /*
1266  * sync_super for 0.90.0
1267  */
1268 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1269 {
1270 	mdp_super_t *sb;
1271 	mdk_rdev_t *rdev2;
1272 	int next_spare = mddev->raid_disks;
1273 
1274 
1275 	/* make rdev->sb match mddev data..
1276 	 *
1277 	 * 1/ zero out disks
1278 	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1279 	 * 3/ any empty disks < next_spare become removed
1280 	 *
1281 	 * disks[0] gets initialised to REMOVED because
1282 	 * we cannot be sure from other fields if it has
1283 	 * been initialised or not.
1284 	 */
1285 	int i;
1286 	int active=0, working=0,failed=0,spare=0,nr_disks=0;
1287 
1288 	rdev->sb_size = MD_SB_BYTES;
1289 
1290 	sb = page_address(rdev->sb_page);
1291 
1292 	memset(sb, 0, sizeof(*sb));
1293 
1294 	sb->md_magic = MD_SB_MAGIC;
1295 	sb->major_version = mddev->major_version;
1296 	sb->patch_version = mddev->patch_version;
1297 	sb->gvalid_words  = 0; /* ignored */
1298 	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1299 	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1300 	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1301 	memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1302 
1303 	sb->ctime = mddev->ctime;
1304 	sb->level = mddev->level;
1305 	sb->size = mddev->dev_sectors / 2;
1306 	sb->raid_disks = mddev->raid_disks;
1307 	sb->md_minor = mddev->md_minor;
1308 	sb->not_persistent = 0;
1309 	sb->utime = mddev->utime;
1310 	sb->state = 0;
1311 	sb->events_hi = (mddev->events>>32);
1312 	sb->events_lo = (u32)mddev->events;
1313 
1314 	if (mddev->reshape_position == MaxSector)
1315 		sb->minor_version = 90;
1316 	else {
1317 		sb->minor_version = 91;
1318 		sb->reshape_position = mddev->reshape_position;
1319 		sb->new_level = mddev->new_level;
1320 		sb->delta_disks = mddev->delta_disks;
1321 		sb->new_layout = mddev->new_layout;
1322 		sb->new_chunk = mddev->new_chunk_sectors << 9;
1323 	}
1324 	mddev->minor_version = sb->minor_version;
1325 	if (mddev->in_sync)
1326 	{
1327 		sb->recovery_cp = mddev->recovery_cp;
1328 		sb->cp_events_hi = (mddev->events>>32);
1329 		sb->cp_events_lo = (u32)mddev->events;
1330 		if (mddev->recovery_cp == MaxSector)
1331 			sb->state = (1<< MD_SB_CLEAN);
1332 	} else
1333 		sb->recovery_cp = 0;
1334 
1335 	sb->layout = mddev->layout;
1336 	sb->chunk_size = mddev->chunk_sectors << 9;
1337 
1338 	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1339 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1340 
1341 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
1342 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1343 		mdp_disk_t *d;
1344 		int desc_nr;
1345 		int is_active = test_bit(In_sync, &rdev2->flags);
1346 
1347 		if (rdev2->raid_disk >= 0 &&
1348 		    sb->minor_version >= 91)
1349 			/* we have nowhere to store the recovery_offset,
1350 			 * but if it is not below the reshape_position,
1351 			 * we can piggy-back on that.
1352 			 */
1353 			is_active = 1;
1354 		if (rdev2->raid_disk < 0 ||
1355 		    test_bit(Faulty, &rdev2->flags))
1356 			is_active = 0;
1357 		if (is_active)
1358 			desc_nr = rdev2->raid_disk;
1359 		else
1360 			desc_nr = next_spare++;
1361 		rdev2->desc_nr = desc_nr;
1362 		d = &sb->disks[rdev2->desc_nr];
1363 		nr_disks++;
1364 		d->number = rdev2->desc_nr;
1365 		d->major = MAJOR(rdev2->bdev->bd_dev);
1366 		d->minor = MINOR(rdev2->bdev->bd_dev);
1367 		if (is_active)
1368 			d->raid_disk = rdev2->raid_disk;
1369 		else
1370 			d->raid_disk = rdev2->desc_nr; /* compatibility */
1371 		if (test_bit(Faulty, &rdev2->flags))
1372 			d->state = (1<<MD_DISK_FAULTY);
1373 		else if (is_active) {
1374 			d->state = (1<<MD_DISK_ACTIVE);
1375 			if (test_bit(In_sync, &rdev2->flags))
1376 				d->state |= (1<<MD_DISK_SYNC);
1377 			active++;
1378 			working++;
1379 		} else {
1380 			d->state = 0;
1381 			spare++;
1382 			working++;
1383 		}
1384 		if (test_bit(WriteMostly, &rdev2->flags))
1385 			d->state |= (1<<MD_DISK_WRITEMOSTLY);
1386 	}
1387 	/* now set the "removed" and "faulty" bits on any missing devices */
1388 	for (i=0 ; i < mddev->raid_disks ; i++) {
1389 		mdp_disk_t *d = &sb->disks[i];
1390 		if (d->state == 0 && d->number == 0) {
1391 			d->number = i;
1392 			d->raid_disk = i;
1393 			d->state = (1<<MD_DISK_REMOVED);
1394 			d->state |= (1<<MD_DISK_FAULTY);
1395 			failed++;
1396 		}
1397 	}
1398 	sb->nr_disks = nr_disks;
1399 	sb->active_disks = active;
1400 	sb->working_disks = working;
1401 	sb->failed_disks = failed;
1402 	sb->spare_disks = spare;
1403 
1404 	sb->this_disk = sb->disks[rdev->desc_nr];
1405 	sb->sb_csum = calc_sb_csum(sb);
1406 }
1407 
1408 /*
1409  * rdev_size_change for 0.90.0
1410  */
1411 static unsigned long long
1412 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1413 {
1414 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1415 		return 0; /* component must fit device */
1416 	if (rdev->mddev->bitmap_info.offset)
1417 		return 0; /* can't move bitmap */
1418 	rdev->sb_start = calc_dev_sboffset(rdev);
1419 	if (!num_sectors || num_sectors > rdev->sb_start)
1420 		num_sectors = rdev->sb_start;
1421 	/* Limit to 4TB as metadata cannot record more than that.
1422 	 * 4TB == 2^32 KB, or 2*2^32 sectors.
1423 	 */
1424 	if (num_sectors >= (2ULL << 32))
1425 		num_sectors = (2ULL << 32) - 2;
1426 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1427 		       rdev->sb_page);
1428 	md_super_wait(rdev->mddev);
1429 	return num_sectors;
1430 }
1431 
1432 
1433 /*
1434  * version 1 superblock
1435  */
1436 
1437 static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
1438 {
1439 	__le32 disk_csum;
1440 	u32 csum;
1441 	unsigned long long newcsum;
1442 	int size = 256 + le32_to_cpu(sb->max_dev)*2;
1443 	__le32 *isuper = (__le32*)sb;
1444 	int i;
1445 
1446 	disk_csum = sb->sb_csum;
1447 	sb->sb_csum = 0;
1448 	newcsum = 0;
1449 	for (i=0; size>=4; size -= 4 )
1450 		newcsum += le32_to_cpu(*isuper++);
1451 
1452 	if (size == 2)
1453 		newcsum += le16_to_cpu(*(__le16*) isuper);
1454 
1455 	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1456 	sb->sb_csum = disk_csum;
1457 	return cpu_to_le32(csum);
1458 }
1459 
1460 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
1461 			    int acknowledged);
1462 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
1463 {
1464 	struct mdp_superblock_1 *sb;
1465 	int ret;
1466 	sector_t sb_start;
1467 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1468 	int bmask;
1469 
1470 	/*
1471 	 * Calculate the position of the superblock in 512byte sectors.
1472 	 * It is always aligned to a 4K boundary and
1473 	 * depeding on minor_version, it can be:
1474 	 * 0: At least 8K, but less than 12K, from end of device
1475 	 * 1: At start of device
1476 	 * 2: 4K from start of device.
1477 	 */
1478 	switch(minor_version) {
1479 	case 0:
1480 		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1481 		sb_start -= 8*2;
1482 		sb_start &= ~(sector_t)(4*2-1);
1483 		break;
1484 	case 1:
1485 		sb_start = 0;
1486 		break;
1487 	case 2:
1488 		sb_start = 8;
1489 		break;
1490 	default:
1491 		return -EINVAL;
1492 	}
1493 	rdev->sb_start = sb_start;
1494 
1495 	/* superblock is rarely larger than 1K, but it can be larger,
1496 	 * and it is safe to read 4k, so we do that
1497 	 */
1498 	ret = read_disk_sb(rdev, 4096);
1499 	if (ret) return ret;
1500 
1501 
1502 	sb = page_address(rdev->sb_page);
1503 
1504 	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1505 	    sb->major_version != cpu_to_le32(1) ||
1506 	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1507 	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1508 	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1509 		return -EINVAL;
1510 
1511 	if (calc_sb_1_csum(sb) != sb->sb_csum) {
1512 		printk("md: invalid superblock checksum on %s\n",
1513 			bdevname(rdev->bdev,b));
1514 		return -EINVAL;
1515 	}
1516 	if (le64_to_cpu(sb->data_size) < 10) {
1517 		printk("md: data_size too small on %s\n",
1518 		       bdevname(rdev->bdev,b));
1519 		return -EINVAL;
1520 	}
1521 
1522 	rdev->preferred_minor = 0xffff;
1523 	rdev->data_offset = le64_to_cpu(sb->data_offset);
1524 	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1525 
1526 	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1527 	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1528 	if (rdev->sb_size & bmask)
1529 		rdev->sb_size = (rdev->sb_size | bmask) + 1;
1530 
1531 	if (minor_version
1532 	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
1533 		return -EINVAL;
1534 
1535 	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1536 		rdev->desc_nr = -1;
1537 	else
1538 		rdev->desc_nr = le32_to_cpu(sb->dev_number);
1539 
1540 	if (!rdev->bb_page) {
1541 		rdev->bb_page = alloc_page(GFP_KERNEL);
1542 		if (!rdev->bb_page)
1543 			return -ENOMEM;
1544 	}
1545 	if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1546 	    rdev->badblocks.count == 0) {
1547 		/* need to load the bad block list.
1548 		 * Currently we limit it to one page.
1549 		 */
1550 		s32 offset;
1551 		sector_t bb_sector;
1552 		u64 *bbp;
1553 		int i;
1554 		int sectors = le16_to_cpu(sb->bblog_size);
1555 		if (sectors > (PAGE_SIZE / 512))
1556 			return -EINVAL;
1557 		offset = le32_to_cpu(sb->bblog_offset);
1558 		if (offset == 0)
1559 			return -EINVAL;
1560 		bb_sector = (long long)offset;
1561 		if (!sync_page_io(rdev, bb_sector, sectors << 9,
1562 				  rdev->bb_page, READ, true))
1563 			return -EIO;
1564 		bbp = (u64 *)page_address(rdev->bb_page);
1565 		rdev->badblocks.shift = sb->bblog_shift;
1566 		for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1567 			u64 bb = le64_to_cpu(*bbp);
1568 			int count = bb & (0x3ff);
1569 			u64 sector = bb >> 10;
1570 			sector <<= sb->bblog_shift;
1571 			count <<= sb->bblog_shift;
1572 			if (bb + 1 == 0)
1573 				break;
1574 			if (md_set_badblocks(&rdev->badblocks,
1575 					     sector, count, 1) == 0)
1576 				return -EINVAL;
1577 		}
1578 	} else if (sb->bblog_offset == 0)
1579 		rdev->badblocks.shift = -1;
1580 
1581 	if (!refdev) {
1582 		ret = 1;
1583 	} else {
1584 		__u64 ev1, ev2;
1585 		struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1586 
1587 		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1588 		    sb->level != refsb->level ||
1589 		    sb->layout != refsb->layout ||
1590 		    sb->chunksize != refsb->chunksize) {
1591 			printk(KERN_WARNING "md: %s has strangely different"
1592 				" superblock to %s\n",
1593 				bdevname(rdev->bdev,b),
1594 				bdevname(refdev->bdev,b2));
1595 			return -EINVAL;
1596 		}
1597 		ev1 = le64_to_cpu(sb->events);
1598 		ev2 = le64_to_cpu(refsb->events);
1599 
1600 		if (ev1 > ev2)
1601 			ret = 1;
1602 		else
1603 			ret = 0;
1604 	}
1605 	if (minor_version)
1606 		rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
1607 			le64_to_cpu(sb->data_offset);
1608 	else
1609 		rdev->sectors = rdev->sb_start;
1610 	if (rdev->sectors < le64_to_cpu(sb->data_size))
1611 		return -EINVAL;
1612 	rdev->sectors = le64_to_cpu(sb->data_size);
1613 	if (le64_to_cpu(sb->size) > rdev->sectors)
1614 		return -EINVAL;
1615 	return ret;
1616 }
1617 
1618 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
1619 {
1620 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1621 	__u64 ev1 = le64_to_cpu(sb->events);
1622 
1623 	rdev->raid_disk = -1;
1624 	clear_bit(Faulty, &rdev->flags);
1625 	clear_bit(In_sync, &rdev->flags);
1626 	clear_bit(WriteMostly, &rdev->flags);
1627 
1628 	if (mddev->raid_disks == 0) {
1629 		mddev->major_version = 1;
1630 		mddev->patch_version = 0;
1631 		mddev->external = 0;
1632 		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1633 		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
1634 		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
1635 		mddev->level = le32_to_cpu(sb->level);
1636 		mddev->clevel[0] = 0;
1637 		mddev->layout = le32_to_cpu(sb->layout);
1638 		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1639 		mddev->dev_sectors = le64_to_cpu(sb->size);
1640 		mddev->events = ev1;
1641 		mddev->bitmap_info.offset = 0;
1642 		mddev->bitmap_info.default_offset = 1024 >> 9;
1643 
1644 		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1645 		memcpy(mddev->uuid, sb->set_uuid, 16);
1646 
1647 		mddev->max_disks =  (4096-256)/2;
1648 
1649 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1650 		    mddev->bitmap_info.file == NULL )
1651 			mddev->bitmap_info.offset =
1652 				(__s32)le32_to_cpu(sb->bitmap_offset);
1653 
1654 		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1655 			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1656 			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1657 			mddev->new_level = le32_to_cpu(sb->new_level);
1658 			mddev->new_layout = le32_to_cpu(sb->new_layout);
1659 			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1660 		} else {
1661 			mddev->reshape_position = MaxSector;
1662 			mddev->delta_disks = 0;
1663 			mddev->new_level = mddev->level;
1664 			mddev->new_layout = mddev->layout;
1665 			mddev->new_chunk_sectors = mddev->chunk_sectors;
1666 		}
1667 
1668 	} else if (mddev->pers == NULL) {
1669 		/* Insist of good event counter while assembling, except for
1670 		 * spares (which don't need an event count) */
1671 		++ev1;
1672 		if (rdev->desc_nr >= 0 &&
1673 		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1674 		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
1675 			if (ev1 < mddev->events)
1676 				return -EINVAL;
1677 	} else if (mddev->bitmap) {
1678 		/* If adding to array with a bitmap, then we can accept an
1679 		 * older device, but not too old.
1680 		 */
1681 		if (ev1 < mddev->bitmap->events_cleared)
1682 			return 0;
1683 	} else {
1684 		if (ev1 < mddev->events)
1685 			/* just a hot-add of a new device, leave raid_disk at -1 */
1686 			return 0;
1687 	}
1688 	if (mddev->level != LEVEL_MULTIPATH) {
1689 		int role;
1690 		if (rdev->desc_nr < 0 ||
1691 		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1692 			role = 0xffff;
1693 			rdev->desc_nr = -1;
1694 		} else
1695 			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1696 		switch(role) {
1697 		case 0xffff: /* spare */
1698 			break;
1699 		case 0xfffe: /* faulty */
1700 			set_bit(Faulty, &rdev->flags);
1701 			break;
1702 		default:
1703 			if ((le32_to_cpu(sb->feature_map) &
1704 			     MD_FEATURE_RECOVERY_OFFSET))
1705 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1706 			else
1707 				set_bit(In_sync, &rdev->flags);
1708 			rdev->raid_disk = role;
1709 			break;
1710 		}
1711 		if (sb->devflags & WriteMostly1)
1712 			set_bit(WriteMostly, &rdev->flags);
1713 	} else /* MULTIPATH are always insync */
1714 		set_bit(In_sync, &rdev->flags);
1715 
1716 	return 0;
1717 }
1718 
1719 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1720 {
1721 	struct mdp_superblock_1 *sb;
1722 	mdk_rdev_t *rdev2;
1723 	int max_dev, i;
1724 	/* make rdev->sb match mddev and rdev data. */
1725 
1726 	sb = page_address(rdev->sb_page);
1727 
1728 	sb->feature_map = 0;
1729 	sb->pad0 = 0;
1730 	sb->recovery_offset = cpu_to_le64(0);
1731 	memset(sb->pad1, 0, sizeof(sb->pad1));
1732 	memset(sb->pad3, 0, sizeof(sb->pad3));
1733 
1734 	sb->utime = cpu_to_le64((__u64)mddev->utime);
1735 	sb->events = cpu_to_le64(mddev->events);
1736 	if (mddev->in_sync)
1737 		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1738 	else
1739 		sb->resync_offset = cpu_to_le64(0);
1740 
1741 	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1742 
1743 	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1744 	sb->size = cpu_to_le64(mddev->dev_sectors);
1745 	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1746 	sb->level = cpu_to_le32(mddev->level);
1747 	sb->layout = cpu_to_le32(mddev->layout);
1748 
1749 	if (test_bit(WriteMostly, &rdev->flags))
1750 		sb->devflags |= WriteMostly1;
1751 	else
1752 		sb->devflags &= ~WriteMostly1;
1753 
1754 	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1755 		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1756 		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1757 	}
1758 
1759 	if (rdev->raid_disk >= 0 &&
1760 	    !test_bit(In_sync, &rdev->flags)) {
1761 		sb->feature_map |=
1762 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1763 		sb->recovery_offset =
1764 			cpu_to_le64(rdev->recovery_offset);
1765 	}
1766 
1767 	if (mddev->reshape_position != MaxSector) {
1768 		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1769 		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1770 		sb->new_layout = cpu_to_le32(mddev->new_layout);
1771 		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1772 		sb->new_level = cpu_to_le32(mddev->new_level);
1773 		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1774 	}
1775 
1776 	if (rdev->badblocks.count == 0)
1777 		/* Nothing to do for bad blocks*/ ;
1778 	else if (sb->bblog_offset == 0)
1779 		/* Cannot record bad blocks on this device */
1780 		md_error(mddev, rdev);
1781 	else {
1782 		struct badblocks *bb = &rdev->badblocks;
1783 		u64 *bbp = (u64 *)page_address(rdev->bb_page);
1784 		u64 *p = bb->page;
1785 		sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1786 		if (bb->changed) {
1787 			unsigned seq;
1788 
1789 retry:
1790 			seq = read_seqbegin(&bb->lock);
1791 
1792 			memset(bbp, 0xff, PAGE_SIZE);
1793 
1794 			for (i = 0 ; i < bb->count ; i++) {
1795 				u64 internal_bb = *p++;
1796 				u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1797 						| BB_LEN(internal_bb));
1798 				*bbp++ = cpu_to_le64(store_bb);
1799 			}
1800 			if (read_seqretry(&bb->lock, seq))
1801 				goto retry;
1802 
1803 			bb->sector = (rdev->sb_start +
1804 				      (int)le32_to_cpu(sb->bblog_offset));
1805 			bb->size = le16_to_cpu(sb->bblog_size);
1806 			bb->changed = 0;
1807 		}
1808 	}
1809 
1810 	max_dev = 0;
1811 	list_for_each_entry(rdev2, &mddev->disks, same_set)
1812 		if (rdev2->desc_nr+1 > max_dev)
1813 			max_dev = rdev2->desc_nr+1;
1814 
1815 	if (max_dev > le32_to_cpu(sb->max_dev)) {
1816 		int bmask;
1817 		sb->max_dev = cpu_to_le32(max_dev);
1818 		rdev->sb_size = max_dev * 2 + 256;
1819 		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1820 		if (rdev->sb_size & bmask)
1821 			rdev->sb_size = (rdev->sb_size | bmask) + 1;
1822 	} else
1823 		max_dev = le32_to_cpu(sb->max_dev);
1824 
1825 	for (i=0; i<max_dev;i++)
1826 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
1827 
1828 	list_for_each_entry(rdev2, &mddev->disks, same_set) {
1829 		i = rdev2->desc_nr;
1830 		if (test_bit(Faulty, &rdev2->flags))
1831 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
1832 		else if (test_bit(In_sync, &rdev2->flags))
1833 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1834 		else if (rdev2->raid_disk >= 0)
1835 			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1836 		else
1837 			sb->dev_roles[i] = cpu_to_le16(0xffff);
1838 	}
1839 
1840 	sb->sb_csum = calc_sb_1_csum(sb);
1841 }
1842 
1843 static unsigned long long
1844 super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
1845 {
1846 	struct mdp_superblock_1 *sb;
1847 	sector_t max_sectors;
1848 	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1849 		return 0; /* component must fit device */
1850 	if (rdev->sb_start < rdev->data_offset) {
1851 		/* minor versions 1 and 2; superblock before data */
1852 		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1853 		max_sectors -= rdev->data_offset;
1854 		if (!num_sectors || num_sectors > max_sectors)
1855 			num_sectors = max_sectors;
1856 	} else if (rdev->mddev->bitmap_info.offset) {
1857 		/* minor version 0 with bitmap we can't move */
1858 		return 0;
1859 	} else {
1860 		/* minor version 0; superblock after data */
1861 		sector_t sb_start;
1862 		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1863 		sb_start &= ~(sector_t)(4*2 - 1);
1864 		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1865 		if (!num_sectors || num_sectors > max_sectors)
1866 			num_sectors = max_sectors;
1867 		rdev->sb_start = sb_start;
1868 	}
1869 	sb = page_address(rdev->sb_page);
1870 	sb->data_size = cpu_to_le64(num_sectors);
1871 	sb->super_offset = rdev->sb_start;
1872 	sb->sb_csum = calc_sb_1_csum(sb);
1873 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1874 		       rdev->sb_page);
1875 	md_super_wait(rdev->mddev);
1876 	return num_sectors;
1877 }
1878 
1879 static struct super_type super_types[] = {
1880 	[0] = {
1881 		.name	= "0.90.0",
1882 		.owner	= THIS_MODULE,
1883 		.load_super	    = super_90_load,
1884 		.validate_super	    = super_90_validate,
1885 		.sync_super	    = super_90_sync,
1886 		.rdev_size_change   = super_90_rdev_size_change,
1887 	},
1888 	[1] = {
1889 		.name	= "md-1",
1890 		.owner	= THIS_MODULE,
1891 		.load_super	    = super_1_load,
1892 		.validate_super	    = super_1_validate,
1893 		.sync_super	    = super_1_sync,
1894 		.rdev_size_change   = super_1_rdev_size_change,
1895 	},
1896 };
1897 
1898 static void sync_super(mddev_t *mddev, mdk_rdev_t *rdev)
1899 {
1900 	if (mddev->sync_super) {
1901 		mddev->sync_super(mddev, rdev);
1902 		return;
1903 	}
1904 
1905 	BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1906 
1907 	super_types[mddev->major_version].sync_super(mddev, rdev);
1908 }
1909 
1910 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1911 {
1912 	mdk_rdev_t *rdev, *rdev2;
1913 
1914 	rcu_read_lock();
1915 	rdev_for_each_rcu(rdev, mddev1)
1916 		rdev_for_each_rcu(rdev2, mddev2)
1917 			if (rdev->bdev->bd_contains ==
1918 			    rdev2->bdev->bd_contains) {
1919 				rcu_read_unlock();
1920 				return 1;
1921 			}
1922 	rcu_read_unlock();
1923 	return 0;
1924 }
1925 
1926 static LIST_HEAD(pending_raid_disks);
1927 
1928 /*
1929  * Try to register data integrity profile for an mddev
1930  *
1931  * This is called when an array is started and after a disk has been kicked
1932  * from the array. It only succeeds if all working and active component devices
1933  * are integrity capable with matching profiles.
1934  */
1935 int md_integrity_register(mddev_t *mddev)
1936 {
1937 	mdk_rdev_t *rdev, *reference = NULL;
1938 
1939 	if (list_empty(&mddev->disks))
1940 		return 0; /* nothing to do */
1941 	if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1942 		return 0; /* shouldn't register, or already is */
1943 	list_for_each_entry(rdev, &mddev->disks, same_set) {
1944 		/* skip spares and non-functional disks */
1945 		if (test_bit(Faulty, &rdev->flags))
1946 			continue;
1947 		if (rdev->raid_disk < 0)
1948 			continue;
1949 		if (!reference) {
1950 			/* Use the first rdev as the reference */
1951 			reference = rdev;
1952 			continue;
1953 		}
1954 		/* does this rdev's profile match the reference profile? */
1955 		if (blk_integrity_compare(reference->bdev->bd_disk,
1956 				rdev->bdev->bd_disk) < 0)
1957 			return -EINVAL;
1958 	}
1959 	if (!reference || !bdev_get_integrity(reference->bdev))
1960 		return 0;
1961 	/*
1962 	 * All component devices are integrity capable and have matching
1963 	 * profiles, register the common profile for the md device.
1964 	 */
1965 	if (blk_integrity_register(mddev->gendisk,
1966 			bdev_get_integrity(reference->bdev)) != 0) {
1967 		printk(KERN_ERR "md: failed to register integrity for %s\n",
1968 			mdname(mddev));
1969 		return -EINVAL;
1970 	}
1971 	printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
1972 	if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
1973 		printk(KERN_ERR "md: failed to create integrity pool for %s\n",
1974 		       mdname(mddev));
1975 		return -EINVAL;
1976 	}
1977 	return 0;
1978 }
1979 EXPORT_SYMBOL(md_integrity_register);
1980 
1981 /* Disable data integrity if non-capable/non-matching disk is being added */
1982 void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
1983 {
1984 	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
1985 	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);
1986 
1987 	if (!bi_mddev) /* nothing to do */
1988 		return;
1989 	if (rdev->raid_disk < 0) /* skip spares */
1990 		return;
1991 	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
1992 					     rdev->bdev->bd_disk) >= 0)
1993 		return;
1994 	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
1995 	blk_integrity_unregister(mddev->gendisk);
1996 }
1997 EXPORT_SYMBOL(md_integrity_add_rdev);
1998 
1999 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
2000 {
2001 	char b[BDEVNAME_SIZE];
2002 	struct kobject *ko;
2003 	char *s;
2004 	int err;
2005 
2006 	if (rdev->mddev) {
2007 		MD_BUG();
2008 		return -EINVAL;
2009 	}
2010 
2011 	/* prevent duplicates */
2012 	if (find_rdev(mddev, rdev->bdev->bd_dev))
2013 		return -EEXIST;
2014 
2015 	/* make sure rdev->sectors exceeds mddev->dev_sectors */
2016 	if (rdev->sectors && (mddev->dev_sectors == 0 ||
2017 			rdev->sectors < mddev->dev_sectors)) {
2018 		if (mddev->pers) {
2019 			/* Cannot change size, so fail
2020 			 * If mddev->level <= 0, then we don't care
2021 			 * about aligning sizes (e.g. linear)
2022 			 */
2023 			if (mddev->level > 0)
2024 				return -ENOSPC;
2025 		} else
2026 			mddev->dev_sectors = rdev->sectors;
2027 	}
2028 
2029 	/* Verify rdev->desc_nr is unique.
2030 	 * If it is -1, assign a free number, else
2031 	 * check number is not in use
2032 	 */
2033 	if (rdev->desc_nr < 0) {
2034 		int choice = 0;
2035 		if (mddev->pers) choice = mddev->raid_disks;
2036 		while (find_rdev_nr(mddev, choice))
2037 			choice++;
2038 		rdev->desc_nr = choice;
2039 	} else {
2040 		if (find_rdev_nr(mddev, rdev->desc_nr))
2041 			return -EBUSY;
2042 	}
2043 	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2044 		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2045 		       mdname(mddev), mddev->max_disks);
2046 		return -EBUSY;
2047 	}
2048 	bdevname(rdev->bdev,b);
2049 	while ( (s=strchr(b, '/')) != NULL)
2050 		*s = '!';
2051 
2052 	rdev->mddev = mddev;
2053 	printk(KERN_INFO "md: bind<%s>\n", b);
2054 
2055 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2056 		goto fail;
2057 
2058 	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2059 	if (sysfs_create_link(&rdev->kobj, ko, "block"))
2060 		/* failure here is OK */;
2061 	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2062 
2063 	list_add_rcu(&rdev->same_set, &mddev->disks);
2064 	bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2065 
2066 	/* May as well allow recovery to be retried once */
2067 	mddev->recovery_disabled++;
2068 
2069 	return 0;
2070 
2071  fail:
2072 	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2073 	       b, mdname(mddev));
2074 	return err;
2075 }
2076 
2077 static void md_delayed_delete(struct work_struct *ws)
2078 {
2079 	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
2080 	kobject_del(&rdev->kobj);
2081 	kobject_put(&rdev->kobj);
2082 }
2083 
2084 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
2085 {
2086 	char b[BDEVNAME_SIZE];
2087 	if (!rdev->mddev) {
2088 		MD_BUG();
2089 		return;
2090 	}
2091 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2092 	list_del_rcu(&rdev->same_set);
2093 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2094 	rdev->mddev = NULL;
2095 	sysfs_remove_link(&rdev->kobj, "block");
2096 	sysfs_put(rdev->sysfs_state);
2097 	rdev->sysfs_state = NULL;
2098 	kfree(rdev->badblocks.page);
2099 	rdev->badblocks.count = 0;
2100 	rdev->badblocks.page = NULL;
2101 	/* We need to delay this, otherwise we can deadlock when
2102 	 * writing to 'remove' to "dev/state".  We also need
2103 	 * to delay it due to rcu usage.
2104 	 */
2105 	synchronize_rcu();
2106 	INIT_WORK(&rdev->del_work, md_delayed_delete);
2107 	kobject_get(&rdev->kobj);
2108 	queue_work(md_misc_wq, &rdev->del_work);
2109 }
2110 
2111 /*
2112  * prevent the device from being mounted, repartitioned or
2113  * otherwise reused by a RAID array (or any other kernel
2114  * subsystem), by bd_claiming the device.
2115  */
2116 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
2117 {
2118 	int err = 0;
2119 	struct block_device *bdev;
2120 	char b[BDEVNAME_SIZE];
2121 
2122 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2123 				 shared ? (mdk_rdev_t *)lock_rdev : rdev);
2124 	if (IS_ERR(bdev)) {
2125 		printk(KERN_ERR "md: could not open %s.\n",
2126 			__bdevname(dev, b));
2127 		return PTR_ERR(bdev);
2128 	}
2129 	rdev->bdev = bdev;
2130 	return err;
2131 }
2132 
2133 static void unlock_rdev(mdk_rdev_t *rdev)
2134 {
2135 	struct block_device *bdev = rdev->bdev;
2136 	rdev->bdev = NULL;
2137 	if (!bdev)
2138 		MD_BUG();
2139 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2140 }
2141 
2142 void md_autodetect_dev(dev_t dev);
2143 
2144 static void export_rdev(mdk_rdev_t * rdev)
2145 {
2146 	char b[BDEVNAME_SIZE];
2147 	printk(KERN_INFO "md: export_rdev(%s)\n",
2148 		bdevname(rdev->bdev,b));
2149 	if (rdev->mddev)
2150 		MD_BUG();
2151 	free_disk_sb(rdev);
2152 #ifndef MODULE
2153 	if (test_bit(AutoDetected, &rdev->flags))
2154 		md_autodetect_dev(rdev->bdev->bd_dev);
2155 #endif
2156 	unlock_rdev(rdev);
2157 	kobject_put(&rdev->kobj);
2158 }
2159 
2160 static void kick_rdev_from_array(mdk_rdev_t * rdev)
2161 {
2162 	unbind_rdev_from_array(rdev);
2163 	export_rdev(rdev);
2164 }
2165 
2166 static void export_array(mddev_t *mddev)
2167 {
2168 	mdk_rdev_t *rdev, *tmp;
2169 
2170 	rdev_for_each(rdev, tmp, mddev) {
2171 		if (!rdev->mddev) {
2172 			MD_BUG();
2173 			continue;
2174 		}
2175 		kick_rdev_from_array(rdev);
2176 	}
2177 	if (!list_empty(&mddev->disks))
2178 		MD_BUG();
2179 	mddev->raid_disks = 0;
2180 	mddev->major_version = 0;
2181 }
2182 
2183 static void print_desc(mdp_disk_t *desc)
2184 {
2185 	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
2186 		desc->major,desc->minor,desc->raid_disk,desc->state);
2187 }
2188 
2189 static void print_sb_90(mdp_super_t *sb)
2190 {
2191 	int i;
2192 
2193 	printk(KERN_INFO
2194 		"md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
2195 		sb->major_version, sb->minor_version, sb->patch_version,
2196 		sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
2197 		sb->ctime);
2198 	printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
2199 		sb->level, sb->size, sb->nr_disks, sb->raid_disks,
2200 		sb->md_minor, sb->layout, sb->chunk_size);
2201 	printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
2202 		" FD:%d SD:%d CSUM:%08x E:%08lx\n",
2203 		sb->utime, sb->state, sb->active_disks, sb->working_disks,
2204 		sb->failed_disks, sb->spare_disks,
2205 		sb->sb_csum, (unsigned long)sb->events_lo);
2206 
2207 	printk(KERN_INFO);
2208 	for (i = 0; i < MD_SB_DISKS; i++) {
2209 		mdp_disk_t *desc;
2210 
2211 		desc = sb->disks + i;
2212 		if (desc->number || desc->major || desc->minor ||
2213 		    desc->raid_disk || (desc->state && (desc->state != 4))) {
2214 			printk("     D %2d: ", i);
2215 			print_desc(desc);
2216 		}
2217 	}
2218 	printk(KERN_INFO "md:     THIS: ");
2219 	print_desc(&sb->this_disk);
2220 }
2221 
2222 static void print_sb_1(struct mdp_superblock_1 *sb)
2223 {
2224 	__u8 *uuid;
2225 
2226 	uuid = sb->set_uuid;
2227 	printk(KERN_INFO
2228 	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
2229 	       "md:    Name: \"%s\" CT:%llu\n",
2230 		le32_to_cpu(sb->major_version),
2231 		le32_to_cpu(sb->feature_map),
2232 		uuid,
2233 		sb->set_name,
2234 		(unsigned long long)le64_to_cpu(sb->ctime)
2235 		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
2236 
2237 	uuid = sb->device_uuid;
2238 	printk(KERN_INFO
2239 	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
2240 			" RO:%llu\n"
2241 	       "md:     Dev:%08x UUID: %pU\n"
2242 	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
2243 	       "md:         (MaxDev:%u) \n",
2244 		le32_to_cpu(sb->level),
2245 		(unsigned long long)le64_to_cpu(sb->size),
2246 		le32_to_cpu(sb->raid_disks),
2247 		le32_to_cpu(sb->layout),
2248 		le32_to_cpu(sb->chunksize),
2249 		(unsigned long long)le64_to_cpu(sb->data_offset),
2250 		(unsigned long long)le64_to_cpu(sb->data_size),
2251 		(unsigned long long)le64_to_cpu(sb->super_offset),
2252 		(unsigned long long)le64_to_cpu(sb->recovery_offset),
2253 		le32_to_cpu(sb->dev_number),
2254 		uuid,
2255 		sb->devflags,
2256 		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
2257 		(unsigned long long)le64_to_cpu(sb->events),
2258 		(unsigned long long)le64_to_cpu(sb->resync_offset),
2259 		le32_to_cpu(sb->sb_csum),
2260 		le32_to_cpu(sb->max_dev)
2261 		);
2262 }
2263 
2264 static void print_rdev(mdk_rdev_t *rdev, int major_version)
2265 {
2266 	char b[BDEVNAME_SIZE];
2267 	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
2268 		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
2269 	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
2270 	        rdev->desc_nr);
2271 	if (rdev->sb_loaded) {
2272 		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
2273 		switch (major_version) {
2274 		case 0:
2275 			print_sb_90(page_address(rdev->sb_page));
2276 			break;
2277 		case 1:
2278 			print_sb_1(page_address(rdev->sb_page));
2279 			break;
2280 		}
2281 	} else
2282 		printk(KERN_INFO "md: no rdev superblock!\n");
2283 }
2284 
2285 static void md_print_devices(void)
2286 {
2287 	struct list_head *tmp;
2288 	mdk_rdev_t *rdev;
2289 	mddev_t *mddev;
2290 	char b[BDEVNAME_SIZE];
2291 
2292 	printk("\n");
2293 	printk("md:	**********************************\n");
2294 	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
2295 	printk("md:	**********************************\n");
2296 	for_each_mddev(mddev, tmp) {
2297 
2298 		if (mddev->bitmap)
2299 			bitmap_print_sb(mddev->bitmap);
2300 		else
2301 			printk("%s: ", mdname(mddev));
2302 		list_for_each_entry(rdev, &mddev->disks, same_set)
2303 			printk("<%s>", bdevname(rdev->bdev,b));
2304 		printk("\n");
2305 
2306 		list_for_each_entry(rdev, &mddev->disks, same_set)
2307 			print_rdev(rdev, mddev->major_version);
2308 	}
2309 	printk("md:	**********************************\n");
2310 	printk("\n");
2311 }
2312 
2313 
2314 static void sync_sbs(mddev_t * mddev, int nospares)
2315 {
2316 	/* Update each superblock (in-memory image), but
2317 	 * if we are allowed to, skip spares which already
2318 	 * have the right event counter, or have one earlier
2319 	 * (which would mean they aren't being marked as dirty
2320 	 * with the rest of the array)
2321 	 */
2322 	mdk_rdev_t *rdev;
2323 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2324 		if (rdev->sb_events == mddev->events ||
2325 		    (nospares &&
2326 		     rdev->raid_disk < 0 &&
2327 		     rdev->sb_events+1 == mddev->events)) {
2328 			/* Don't update this superblock */
2329 			rdev->sb_loaded = 2;
2330 		} else {
2331 			sync_super(mddev, rdev);
2332 			rdev->sb_loaded = 1;
2333 		}
2334 	}
2335 }
2336 
2337 static void md_update_sb(mddev_t * mddev, int force_change)
2338 {
2339 	mdk_rdev_t *rdev;
2340 	int sync_req;
2341 	int nospares = 0;
2342 	int any_badblocks_changed = 0;
2343 
2344 repeat:
2345 	/* First make sure individual recovery_offsets are correct */
2346 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2347 		if (rdev->raid_disk >= 0 &&
2348 		    mddev->delta_disks >= 0 &&
2349 		    !test_bit(In_sync, &rdev->flags) &&
2350 		    mddev->curr_resync_completed > rdev->recovery_offset)
2351 				rdev->recovery_offset = mddev->curr_resync_completed;
2352 
2353 	}
2354 	if (!mddev->persistent) {
2355 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2356 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2357 		if (!mddev->external) {
2358 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2359 			list_for_each_entry(rdev, &mddev->disks, same_set) {
2360 				if (rdev->badblocks.changed) {
2361 					md_ack_all_badblocks(&rdev->badblocks);
2362 					md_error(mddev, rdev);
2363 				}
2364 				clear_bit(Blocked, &rdev->flags);
2365 				clear_bit(BlockedBadBlocks, &rdev->flags);
2366 				wake_up(&rdev->blocked_wait);
2367 			}
2368 		}
2369 		wake_up(&mddev->sb_wait);
2370 		return;
2371 	}
2372 
2373 	spin_lock_irq(&mddev->write_lock);
2374 
2375 	mddev->utime = get_seconds();
2376 
2377 	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2378 		force_change = 1;
2379 	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2380 		/* just a clean<-> dirty transition, possibly leave spares alone,
2381 		 * though if events isn't the right even/odd, we will have to do
2382 		 * spares after all
2383 		 */
2384 		nospares = 1;
2385 	if (force_change)
2386 		nospares = 0;
2387 	if (mddev->degraded)
2388 		/* If the array is degraded, then skipping spares is both
2389 		 * dangerous and fairly pointless.
2390 		 * Dangerous because a device that was removed from the array
2391 		 * might have a event_count that still looks up-to-date,
2392 		 * so it can be re-added without a resync.
2393 		 * Pointless because if there are any spares to skip,
2394 		 * then a recovery will happen and soon that array won't
2395 		 * be degraded any more and the spare can go back to sleep then.
2396 		 */
2397 		nospares = 0;
2398 
2399 	sync_req = mddev->in_sync;
2400 
2401 	/* If this is just a dirty<->clean transition, and the array is clean
2402 	 * and 'events' is odd, we can roll back to the previous clean state */
2403 	if (nospares
2404 	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2405 	    && mddev->can_decrease_events
2406 	    && mddev->events != 1) {
2407 		mddev->events--;
2408 		mddev->can_decrease_events = 0;
2409 	} else {
2410 		/* otherwise we have to go forward and ... */
2411 		mddev->events ++;
2412 		mddev->can_decrease_events = nospares;
2413 	}
2414 
2415 	if (!mddev->events) {
2416 		/*
2417 		 * oops, this 64-bit counter should never wrap.
2418 		 * Either we are in around ~1 trillion A.C., assuming
2419 		 * 1 reboot per second, or we have a bug:
2420 		 */
2421 		MD_BUG();
2422 		mddev->events --;
2423 	}
2424 
2425 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2426 		if (rdev->badblocks.changed)
2427 			any_badblocks_changed++;
2428 		if (test_bit(Faulty, &rdev->flags))
2429 			set_bit(FaultRecorded, &rdev->flags);
2430 	}
2431 
2432 	sync_sbs(mddev, nospares);
2433 	spin_unlock_irq(&mddev->write_lock);
2434 
2435 	dprintk(KERN_INFO
2436 		"md: updating %s RAID superblock on device (in sync %d)\n",
2437 		mdname(mddev),mddev->in_sync);
2438 
2439 	bitmap_update_sb(mddev->bitmap);
2440 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2441 		char b[BDEVNAME_SIZE];
2442 		dprintk(KERN_INFO "md: ");
2443 		if (rdev->sb_loaded != 1)
2444 			continue; /* no noise on spare devices */
2445 		if (test_bit(Faulty, &rdev->flags))
2446 			dprintk("(skipping faulty ");
2447 
2448 		dprintk("%s ", bdevname(rdev->bdev,b));
2449 		if (!test_bit(Faulty, &rdev->flags)) {
2450 			md_super_write(mddev,rdev,
2451 				       rdev->sb_start, rdev->sb_size,
2452 				       rdev->sb_page);
2453 			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
2454 				bdevname(rdev->bdev,b),
2455 				(unsigned long long)rdev->sb_start);
2456 			rdev->sb_events = mddev->events;
2457 			if (rdev->badblocks.size) {
2458 				md_super_write(mddev, rdev,
2459 					       rdev->badblocks.sector,
2460 					       rdev->badblocks.size << 9,
2461 					       rdev->bb_page);
2462 				rdev->badblocks.size = 0;
2463 			}
2464 
2465 		} else
2466 			dprintk(")\n");
2467 		if (mddev->level == LEVEL_MULTIPATH)
2468 			/* only need to write one superblock... */
2469 			break;
2470 	}
2471 	md_super_wait(mddev);
2472 	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2473 
2474 	spin_lock_irq(&mddev->write_lock);
2475 	if (mddev->in_sync != sync_req ||
2476 	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2477 		/* have to write it out again */
2478 		spin_unlock_irq(&mddev->write_lock);
2479 		goto repeat;
2480 	}
2481 	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2482 	spin_unlock_irq(&mddev->write_lock);
2483 	wake_up(&mddev->sb_wait);
2484 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2485 		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2486 
2487 	list_for_each_entry(rdev, &mddev->disks, same_set) {
2488 		if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2489 			clear_bit(Blocked, &rdev->flags);
2490 
2491 		if (any_badblocks_changed)
2492 			md_ack_all_badblocks(&rdev->badblocks);
2493 		clear_bit(BlockedBadBlocks, &rdev->flags);
2494 		wake_up(&rdev->blocked_wait);
2495 	}
2496 }
2497 
2498 /* words written to sysfs files may, or may not, be \n terminated.
2499  * We want to accept with case. For this we use cmd_match.
2500  */
2501 static int cmd_match(const char *cmd, const char *str)
2502 {
2503 	/* See if cmd, written into a sysfs file, matches
2504 	 * str.  They must either be the same, or cmd can
2505 	 * have a trailing newline
2506 	 */
2507 	while (*cmd && *str && *cmd == *str) {
2508 		cmd++;
2509 		str++;
2510 	}
2511 	if (*cmd == '\n')
2512 		cmd++;
2513 	if (*str || *cmd)
2514 		return 0;
2515 	return 1;
2516 }
2517 
2518 struct rdev_sysfs_entry {
2519 	struct attribute attr;
2520 	ssize_t (*show)(mdk_rdev_t *, char *);
2521 	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
2522 };
2523 
2524 static ssize_t
2525 state_show(mdk_rdev_t *rdev, char *page)
2526 {
2527 	char *sep = "";
2528 	size_t len = 0;
2529 
2530 	if (test_bit(Faulty, &rdev->flags) ||
2531 	    rdev->badblocks.unacked_exist) {
2532 		len+= sprintf(page+len, "%sfaulty",sep);
2533 		sep = ",";
2534 	}
2535 	if (test_bit(In_sync, &rdev->flags)) {
2536 		len += sprintf(page+len, "%sin_sync",sep);
2537 		sep = ",";
2538 	}
2539 	if (test_bit(WriteMostly, &rdev->flags)) {
2540 		len += sprintf(page+len, "%swrite_mostly",sep);
2541 		sep = ",";
2542 	}
2543 	if (test_bit(Blocked, &rdev->flags) ||
2544 	    rdev->badblocks.unacked_exist) {
2545 		len += sprintf(page+len, "%sblocked", sep);
2546 		sep = ",";
2547 	}
2548 	if (!test_bit(Faulty, &rdev->flags) &&
2549 	    !test_bit(In_sync, &rdev->flags)) {
2550 		len += sprintf(page+len, "%sspare", sep);
2551 		sep = ",";
2552 	}
2553 	if (test_bit(WriteErrorSeen, &rdev->flags)) {
2554 		len += sprintf(page+len, "%swrite_error", sep);
2555 		sep = ",";
2556 	}
2557 	return len+sprintf(page+len, "\n");
2558 }
2559 
2560 static ssize_t
2561 state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2562 {
2563 	/* can write
2564 	 *  faulty  - simulates an error
2565 	 *  remove  - disconnects the device
2566 	 *  writemostly - sets write_mostly
2567 	 *  -writemostly - clears write_mostly
2568 	 *  blocked - sets the Blocked flags
2569 	 *  -blocked - clears the Blocked and possibly simulates an error
2570 	 *  insync - sets Insync providing device isn't active
2571 	 *  write_error - sets WriteErrorSeen
2572 	 *  -write_error - clears WriteErrorSeen
2573 	 */
2574 	int err = -EINVAL;
2575 	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2576 		md_error(rdev->mddev, rdev);
2577 		if (test_bit(Faulty, &rdev->flags))
2578 			err = 0;
2579 		else
2580 			err = -EBUSY;
2581 	} else if (cmd_match(buf, "remove")) {
2582 		if (rdev->raid_disk >= 0)
2583 			err = -EBUSY;
2584 		else {
2585 			mddev_t *mddev = rdev->mddev;
2586 			kick_rdev_from_array(rdev);
2587 			if (mddev->pers)
2588 				md_update_sb(mddev, 1);
2589 			md_new_event(mddev);
2590 			err = 0;
2591 		}
2592 	} else if (cmd_match(buf, "writemostly")) {
2593 		set_bit(WriteMostly, &rdev->flags);
2594 		err = 0;
2595 	} else if (cmd_match(buf, "-writemostly")) {
2596 		clear_bit(WriteMostly, &rdev->flags);
2597 		err = 0;
2598 	} else if (cmd_match(buf, "blocked")) {
2599 		set_bit(Blocked, &rdev->flags);
2600 		err = 0;
2601 	} else if (cmd_match(buf, "-blocked")) {
2602 		if (!test_bit(Faulty, &rdev->flags) &&
2603 		    rdev->badblocks.unacked_exist) {
2604 			/* metadata handler doesn't understand badblocks,
2605 			 * so we need to fail the device
2606 			 */
2607 			md_error(rdev->mddev, rdev);
2608 		}
2609 		clear_bit(Blocked, &rdev->flags);
2610 		clear_bit(BlockedBadBlocks, &rdev->flags);
2611 		wake_up(&rdev->blocked_wait);
2612 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2613 		md_wakeup_thread(rdev->mddev->thread);
2614 
2615 		err = 0;
2616 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2617 		set_bit(In_sync, &rdev->flags);
2618 		err = 0;
2619 	} else if (cmd_match(buf, "write_error")) {
2620 		set_bit(WriteErrorSeen, &rdev->flags);
2621 		err = 0;
2622 	} else if (cmd_match(buf, "-write_error")) {
2623 		clear_bit(WriteErrorSeen, &rdev->flags);
2624 		err = 0;
2625 	}
2626 	if (!err)
2627 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2628 	return err ? err : len;
2629 }
2630 static struct rdev_sysfs_entry rdev_state =
2631 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
2632 
2633 static ssize_t
2634 errors_show(mdk_rdev_t *rdev, char *page)
2635 {
2636 	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2637 }
2638 
2639 static ssize_t
2640 errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2641 {
2642 	char *e;
2643 	unsigned long n = simple_strtoul(buf, &e, 10);
2644 	if (*buf && (*e == 0 || *e == '\n')) {
2645 		atomic_set(&rdev->corrected_errors, n);
2646 		return len;
2647 	}
2648 	return -EINVAL;
2649 }
2650 static struct rdev_sysfs_entry rdev_errors =
2651 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2652 
2653 static ssize_t
2654 slot_show(mdk_rdev_t *rdev, char *page)
2655 {
2656 	if (rdev->raid_disk < 0)
2657 		return sprintf(page, "none\n");
2658 	else
2659 		return sprintf(page, "%d\n", rdev->raid_disk);
2660 }
2661 
2662 static ssize_t
2663 slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2664 {
2665 	char *e;
2666 	int err;
2667 	int slot = simple_strtoul(buf, &e, 10);
2668 	if (strncmp(buf, "none", 4)==0)
2669 		slot = -1;
2670 	else if (e==buf || (*e && *e!= '\n'))
2671 		return -EINVAL;
2672 	if (rdev->mddev->pers && slot == -1) {
2673 		/* Setting 'slot' on an active array requires also
2674 		 * updating the 'rd%d' link, and communicating
2675 		 * with the personality with ->hot_*_disk.
2676 		 * For now we only support removing
2677 		 * failed/spare devices.  This normally happens automatically,
2678 		 * but not when the metadata is externally managed.
2679 		 */
2680 		if (rdev->raid_disk == -1)
2681 			return -EEXIST;
2682 		/* personality does all needed checks */
2683 		if (rdev->mddev->pers->hot_remove_disk == NULL)
2684 			return -EINVAL;
2685 		err = rdev->mddev->pers->
2686 			hot_remove_disk(rdev->mddev, rdev->raid_disk);
2687 		if (err)
2688 			return err;
2689 		sysfs_unlink_rdev(rdev->mddev, rdev);
2690 		rdev->raid_disk = -1;
2691 		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2692 		md_wakeup_thread(rdev->mddev->thread);
2693 	} else if (rdev->mddev->pers) {
2694 		mdk_rdev_t *rdev2;
2695 		/* Activating a spare .. or possibly reactivating
2696 		 * if we ever get bitmaps working here.
2697 		 */
2698 
2699 		if (rdev->raid_disk != -1)
2700 			return -EBUSY;
2701 
2702 		if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2703 			return -EBUSY;
2704 
2705 		if (rdev->mddev->pers->hot_add_disk == NULL)
2706 			return -EINVAL;
2707 
2708 		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
2709 			if (rdev2->raid_disk == slot)
2710 				return -EEXIST;
2711 
2712 		if (slot >= rdev->mddev->raid_disks &&
2713 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2714 			return -ENOSPC;
2715 
2716 		rdev->raid_disk = slot;
2717 		if (test_bit(In_sync, &rdev->flags))
2718 			rdev->saved_raid_disk = slot;
2719 		else
2720 			rdev->saved_raid_disk = -1;
2721 		err = rdev->mddev->pers->
2722 			hot_add_disk(rdev->mddev, rdev);
2723 		if (err) {
2724 			rdev->raid_disk = -1;
2725 			return err;
2726 		} else
2727 			sysfs_notify_dirent_safe(rdev->sysfs_state);
2728 		if (sysfs_link_rdev(rdev->mddev, rdev))
2729 			/* failure here is OK */;
2730 		/* don't wakeup anyone, leave that to userspace. */
2731 	} else {
2732 		if (slot >= rdev->mddev->raid_disks &&
2733 		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2734 			return -ENOSPC;
2735 		rdev->raid_disk = slot;
2736 		/* assume it is working */
2737 		clear_bit(Faulty, &rdev->flags);
2738 		clear_bit(WriteMostly, &rdev->flags);
2739 		set_bit(In_sync, &rdev->flags);
2740 		sysfs_notify_dirent_safe(rdev->sysfs_state);
2741 	}
2742 	return len;
2743 }
2744 
2745 
2746 static struct rdev_sysfs_entry rdev_slot =
2747 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2748 
2749 static ssize_t
2750 offset_show(mdk_rdev_t *rdev, char *page)
2751 {
2752 	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2753 }
2754 
2755 static ssize_t
2756 offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2757 {
2758 	char *e;
2759 	unsigned long long offset = simple_strtoull(buf, &e, 10);
2760 	if (e==buf || (*e && *e != '\n'))
2761 		return -EINVAL;
2762 	if (rdev->mddev->pers && rdev->raid_disk >= 0)
2763 		return -EBUSY;
2764 	if (rdev->sectors && rdev->mddev->external)
2765 		/* Must set offset before size, so overlap checks
2766 		 * can be sane */
2767 		return -EBUSY;
2768 	rdev->data_offset = offset;
2769 	return len;
2770 }
2771 
2772 static struct rdev_sysfs_entry rdev_offset =
2773 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2774 
2775 static ssize_t
2776 rdev_size_show(mdk_rdev_t *rdev, char *page)
2777 {
2778 	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2779 }
2780 
2781 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2782 {
2783 	/* check if two start/length pairs overlap */
2784 	if (s1+l1 <= s2)
2785 		return 0;
2786 	if (s2+l2 <= s1)
2787 		return 0;
2788 	return 1;
2789 }
2790 
2791 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2792 {
2793 	unsigned long long blocks;
2794 	sector_t new;
2795 
2796 	if (strict_strtoull(buf, 10, &blocks) < 0)
2797 		return -EINVAL;
2798 
2799 	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2800 		return -EINVAL; /* sector conversion overflow */
2801 
2802 	new = blocks * 2;
2803 	if (new != blocks * 2)
2804 		return -EINVAL; /* unsigned long long to sector_t overflow */
2805 
2806 	*sectors = new;
2807 	return 0;
2808 }
2809 
2810 static ssize_t
2811 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2812 {
2813 	mddev_t *my_mddev = rdev->mddev;
2814 	sector_t oldsectors = rdev->sectors;
2815 	sector_t sectors;
2816 
2817 	if (strict_blocks_to_sectors(buf, &sectors) < 0)
2818 		return -EINVAL;
2819 	if (my_mddev->pers && rdev->raid_disk >= 0) {
2820 		if (my_mddev->persistent) {
2821 			sectors = super_types[my_mddev->major_version].
2822 				rdev_size_change(rdev, sectors);
2823 			if (!sectors)
2824 				return -EBUSY;
2825 		} else if (!sectors)
2826 			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2827 				rdev->data_offset;
2828 	}
2829 	if (sectors < my_mddev->dev_sectors)
2830 		return -EINVAL; /* component must fit device */
2831 
2832 	rdev->sectors = sectors;
2833 	if (sectors > oldsectors && my_mddev->external) {
2834 		/* need to check that all other rdevs with the same ->bdev
2835 		 * do not overlap.  We need to unlock the mddev to avoid
2836 		 * a deadlock.  We have already changed rdev->sectors, and if
2837 		 * we have to change it back, we will have the lock again.
2838 		 */
2839 		mddev_t *mddev;
2840 		int overlap = 0;
2841 		struct list_head *tmp;
2842 
2843 		mddev_unlock(my_mddev);
2844 		for_each_mddev(mddev, tmp) {
2845 			mdk_rdev_t *rdev2;
2846 
2847 			mddev_lock(mddev);
2848 			list_for_each_entry(rdev2, &mddev->disks, same_set)
2849 				if (rdev->bdev == rdev2->bdev &&
2850 				    rdev != rdev2 &&
2851 				    overlaps(rdev->data_offset, rdev->sectors,
2852 					     rdev2->data_offset,
2853 					     rdev2->sectors)) {
2854 					overlap = 1;
2855 					break;
2856 				}
2857 			mddev_unlock(mddev);
2858 			if (overlap) {
2859 				mddev_put(mddev);
2860 				break;
2861 			}
2862 		}
2863 		mddev_lock(my_mddev);
2864 		if (overlap) {
2865 			/* Someone else could have slipped in a size
2866 			 * change here, but doing so is just silly.
2867 			 * We put oldsectors back because we *know* it is
2868 			 * safe, and trust userspace not to race with
2869 			 * itself
2870 			 */
2871 			rdev->sectors = oldsectors;
2872 			return -EBUSY;
2873 		}
2874 	}
2875 	return len;
2876 }
2877 
2878 static struct rdev_sysfs_entry rdev_size =
2879 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
2880 
2881 
2882 static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
2883 {
2884 	unsigned long long recovery_start = rdev->recovery_offset;
2885 
2886 	if (test_bit(In_sync, &rdev->flags) ||
2887 	    recovery_start == MaxSector)
2888 		return sprintf(page, "none\n");
2889 
2890 	return sprintf(page, "%llu\n", recovery_start);
2891 }
2892 
2893 static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
2894 {
2895 	unsigned long long recovery_start;
2896 
2897 	if (cmd_match(buf, "none"))
2898 		recovery_start = MaxSector;
2899 	else if (strict_strtoull(buf, 10, &recovery_start))
2900 		return -EINVAL;
2901 
2902 	if (rdev->mddev->pers &&
2903 	    rdev->raid_disk >= 0)
2904 		return -EBUSY;
2905 
2906 	rdev->recovery_offset = recovery_start;
2907 	if (recovery_start == MaxSector)
2908 		set_bit(In_sync, &rdev->flags);
2909 	else
2910 		clear_bit(In_sync, &rdev->flags);
2911 	return len;
2912 }
2913 
2914 static struct rdev_sysfs_entry rdev_recovery_start =
2915 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
2916 
2917 
2918 static ssize_t
2919 badblocks_show(struct badblocks *bb, char *page, int unack);
2920 static ssize_t
2921 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack);
2922 
2923 static ssize_t bb_show(mdk_rdev_t *rdev, char *page)
2924 {
2925 	return badblocks_show(&rdev->badblocks, page, 0);
2926 }
2927 static ssize_t bb_store(mdk_rdev_t *rdev, const char *page, size_t len)
2928 {
2929 	int rv = badblocks_store(&rdev->badblocks, page, len, 0);
2930 	/* Maybe that ack was all we needed */
2931 	if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
2932 		wake_up(&rdev->blocked_wait);
2933 	return rv;
2934 }
2935 static struct rdev_sysfs_entry rdev_bad_blocks =
2936 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
2937 
2938 
2939 static ssize_t ubb_show(mdk_rdev_t *rdev, char *page)
2940 {
2941 	return badblocks_show(&rdev->badblocks, page, 1);
2942 }
2943 static ssize_t ubb_store(mdk_rdev_t *rdev, const char *page, size_t len)
2944 {
2945 	return badblocks_store(&rdev->badblocks, page, len, 1);
2946 }
2947 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
2948 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
2949 
2950 static struct attribute *rdev_default_attrs[] = {
2951 	&rdev_state.attr,
2952 	&rdev_errors.attr,
2953 	&rdev_slot.attr,
2954 	&rdev_offset.attr,
2955 	&rdev_size.attr,
2956 	&rdev_recovery_start.attr,
2957 	&rdev_bad_blocks.attr,
2958 	&rdev_unack_bad_blocks.attr,
2959 	NULL,
2960 };
2961 static ssize_t
2962 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
2963 {
2964 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2965 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2966 	mddev_t *mddev = rdev->mddev;
2967 	ssize_t rv;
2968 
2969 	if (!entry->show)
2970 		return -EIO;
2971 
2972 	rv = mddev ? mddev_lock(mddev) : -EBUSY;
2973 	if (!rv) {
2974 		if (rdev->mddev == NULL)
2975 			rv = -EBUSY;
2976 		else
2977 			rv = entry->show(rdev, page);
2978 		mddev_unlock(mddev);
2979 	}
2980 	return rv;
2981 }
2982 
2983 static ssize_t
2984 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
2985 	      const char *page, size_t length)
2986 {
2987 	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
2988 	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
2989 	ssize_t rv;
2990 	mddev_t *mddev = rdev->mddev;
2991 
2992 	if (!entry->store)
2993 		return -EIO;
2994 	if (!capable(CAP_SYS_ADMIN))
2995 		return -EACCES;
2996 	rv = mddev ? mddev_lock(mddev): -EBUSY;
2997 	if (!rv) {
2998 		if (rdev->mddev == NULL)
2999 			rv = -EBUSY;
3000 		else
3001 			rv = entry->store(rdev, page, length);
3002 		mddev_unlock(mddev);
3003 	}
3004 	return rv;
3005 }
3006 
3007 static void rdev_free(struct kobject *ko)
3008 {
3009 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
3010 	kfree(rdev);
3011 }
3012 static const struct sysfs_ops rdev_sysfs_ops = {
3013 	.show		= rdev_attr_show,
3014 	.store		= rdev_attr_store,
3015 };
3016 static struct kobj_type rdev_ktype = {
3017 	.release	= rdev_free,
3018 	.sysfs_ops	= &rdev_sysfs_ops,
3019 	.default_attrs	= rdev_default_attrs,
3020 };
3021 
3022 int md_rdev_init(mdk_rdev_t *rdev)
3023 {
3024 	rdev->desc_nr = -1;
3025 	rdev->saved_raid_disk = -1;
3026 	rdev->raid_disk = -1;
3027 	rdev->flags = 0;
3028 	rdev->data_offset = 0;
3029 	rdev->sb_events = 0;
3030 	rdev->last_read_error.tv_sec  = 0;
3031 	rdev->last_read_error.tv_nsec = 0;
3032 	rdev->sb_loaded = 0;
3033 	rdev->bb_page = NULL;
3034 	atomic_set(&rdev->nr_pending, 0);
3035 	atomic_set(&rdev->read_errors, 0);
3036 	atomic_set(&rdev->corrected_errors, 0);
3037 
3038 	INIT_LIST_HEAD(&rdev->same_set);
3039 	init_waitqueue_head(&rdev->blocked_wait);
3040 
3041 	/* Add space to store bad block list.
3042 	 * This reserves the space even on arrays where it cannot
3043 	 * be used - I wonder if that matters
3044 	 */
3045 	rdev->badblocks.count = 0;
3046 	rdev->badblocks.shift = 0;
3047 	rdev->badblocks.page = kmalloc(PAGE_SIZE, GFP_KERNEL);
3048 	seqlock_init(&rdev->badblocks.lock);
3049 	if (rdev->badblocks.page == NULL)
3050 		return -ENOMEM;
3051 
3052 	return 0;
3053 }
3054 EXPORT_SYMBOL_GPL(md_rdev_init);
3055 /*
3056  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3057  *
3058  * mark the device faulty if:
3059  *
3060  *   - the device is nonexistent (zero size)
3061  *   - the device has no valid superblock
3062  *
3063  * a faulty rdev _never_ has rdev->sb set.
3064  */
3065 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
3066 {
3067 	char b[BDEVNAME_SIZE];
3068 	int err;
3069 	mdk_rdev_t *rdev;
3070 	sector_t size;
3071 
3072 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3073 	if (!rdev) {
3074 		printk(KERN_ERR "md: could not alloc mem for new device!\n");
3075 		return ERR_PTR(-ENOMEM);
3076 	}
3077 
3078 	err = md_rdev_init(rdev);
3079 	if (err)
3080 		goto abort_free;
3081 	err = alloc_disk_sb(rdev);
3082 	if (err)
3083 		goto abort_free;
3084 
3085 	err = lock_rdev(rdev, newdev, super_format == -2);
3086 	if (err)
3087 		goto abort_free;
3088 
3089 	kobject_init(&rdev->kobj, &rdev_ktype);
3090 
3091 	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3092 	if (!size) {
3093 		printk(KERN_WARNING
3094 			"md: %s has zero or unknown size, marking faulty!\n",
3095 			bdevname(rdev->bdev,b));
3096 		err = -EINVAL;
3097 		goto abort_free;
3098 	}
3099 
3100 	if (super_format >= 0) {
3101 		err = super_types[super_format].
3102 			load_super(rdev, NULL, super_minor);
3103 		if (err == -EINVAL) {
3104 			printk(KERN_WARNING
3105 				"md: %s does not have a valid v%d.%d "
3106 			       "superblock, not importing!\n",
3107 				bdevname(rdev->bdev,b),
3108 			       super_format, super_minor);
3109 			goto abort_free;
3110 		}
3111 		if (err < 0) {
3112 			printk(KERN_WARNING
3113 				"md: could not read %s's sb, not importing!\n",
3114 				bdevname(rdev->bdev,b));
3115 			goto abort_free;
3116 		}
3117 	}
3118 	if (super_format == -1)
3119 		/* hot-add for 0.90, or non-persistent: so no badblocks */
3120 		rdev->badblocks.shift = -1;
3121 
3122 	return rdev;
3123 
3124 abort_free:
3125 	if (rdev->bdev)
3126 		unlock_rdev(rdev);
3127 	free_disk_sb(rdev);
3128 	kfree(rdev->badblocks.page);
3129 	kfree(rdev);
3130 	return ERR_PTR(err);
3131 }
3132 
3133 /*
3134  * Check a full RAID array for plausibility
3135  */
3136 
3137 
3138 static void analyze_sbs(mddev_t * mddev)
3139 {
3140 	int i;
3141 	mdk_rdev_t *rdev, *freshest, *tmp;
3142 	char b[BDEVNAME_SIZE];
3143 
3144 	freshest = NULL;
3145 	rdev_for_each(rdev, tmp, mddev)
3146 		switch (super_types[mddev->major_version].
3147 			load_super(rdev, freshest, mddev->minor_version)) {
3148 		case 1:
3149 			freshest = rdev;
3150 			break;
3151 		case 0:
3152 			break;
3153 		default:
3154 			printk( KERN_ERR \
3155 				"md: fatal superblock inconsistency in %s"
3156 				" -- removing from array\n",
3157 				bdevname(rdev->bdev,b));
3158 			kick_rdev_from_array(rdev);
3159 		}
3160 
3161 
3162 	super_types[mddev->major_version].
3163 		validate_super(mddev, freshest);
3164 
3165 	i = 0;
3166 	rdev_for_each(rdev, tmp, mddev) {
3167 		if (mddev->max_disks &&
3168 		    (rdev->desc_nr >= mddev->max_disks ||
3169 		     i > mddev->max_disks)) {
3170 			printk(KERN_WARNING
3171 			       "md: %s: %s: only %d devices permitted\n",
3172 			       mdname(mddev), bdevname(rdev->bdev, b),
3173 			       mddev->max_disks);
3174 			kick_rdev_from_array(rdev);
3175 			continue;
3176 		}
3177 		if (rdev != freshest)
3178 			if (super_types[mddev->major_version].
3179 			    validate_super(mddev, rdev)) {
3180 				printk(KERN_WARNING "md: kicking non-fresh %s"
3181 					" from array!\n",
3182 					bdevname(rdev->bdev,b));
3183 				kick_rdev_from_array(rdev);
3184 				continue;
3185 			}
3186 		if (mddev->level == LEVEL_MULTIPATH) {
3187 			rdev->desc_nr = i++;
3188 			rdev->raid_disk = rdev->desc_nr;
3189 			set_bit(In_sync, &rdev->flags);
3190 		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
3191 			rdev->raid_disk = -1;
3192 			clear_bit(In_sync, &rdev->flags);
3193 		}
3194 	}
3195 }
3196 
3197 /* Read a fixed-point number.
3198  * Numbers in sysfs attributes should be in "standard" units where
3199  * possible, so time should be in seconds.
3200  * However we internally use a a much smaller unit such as
3201  * milliseconds or jiffies.
3202  * This function takes a decimal number with a possible fractional
3203  * component, and produces an integer which is the result of
3204  * multiplying that number by 10^'scale'.
3205  * all without any floating-point arithmetic.
3206  */
3207 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3208 {
3209 	unsigned long result = 0;
3210 	long decimals = -1;
3211 	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3212 		if (*cp == '.')
3213 			decimals = 0;
3214 		else if (decimals < scale) {
3215 			unsigned int value;
3216 			value = *cp - '0';
3217 			result = result * 10 + value;
3218 			if (decimals >= 0)
3219 				decimals++;
3220 		}
3221 		cp++;
3222 	}
3223 	if (*cp == '\n')
3224 		cp++;
3225 	if (*cp)
3226 		return -EINVAL;
3227 	if (decimals < 0)
3228 		decimals = 0;
3229 	while (decimals < scale) {
3230 		result *= 10;
3231 		decimals ++;
3232 	}
3233 	*res = result;
3234 	return 0;
3235 }
3236 
3237 
3238 static void md_safemode_timeout(unsigned long data);
3239 
3240 static ssize_t
3241 safe_delay_show(mddev_t *mddev, char *page)
3242 {
3243 	int msec = (mddev->safemode_delay*1000)/HZ;
3244 	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3245 }
3246 static ssize_t
3247 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
3248 {
3249 	unsigned long msec;
3250 
3251 	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3252 		return -EINVAL;
3253 	if (msec == 0)
3254 		mddev->safemode_delay = 0;
3255 	else {
3256 		unsigned long old_delay = mddev->safemode_delay;
3257 		mddev->safemode_delay = (msec*HZ)/1000;
3258 		if (mddev->safemode_delay == 0)
3259 			mddev->safemode_delay = 1;
3260 		if (mddev->safemode_delay < old_delay)
3261 			md_safemode_timeout((unsigned long)mddev);
3262 	}
3263 	return len;
3264 }
3265 static struct md_sysfs_entry md_safe_delay =
3266 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3267 
3268 static ssize_t
3269 level_show(mddev_t *mddev, char *page)
3270 {
3271 	struct mdk_personality *p = mddev->pers;
3272 	if (p)
3273 		return sprintf(page, "%s\n", p->name);
3274 	else if (mddev->clevel[0])
3275 		return sprintf(page, "%s\n", mddev->clevel);
3276 	else if (mddev->level != LEVEL_NONE)
3277 		return sprintf(page, "%d\n", mddev->level);
3278 	else
3279 		return 0;
3280 }
3281 
3282 static ssize_t
3283 level_store(mddev_t *mddev, const char *buf, size_t len)
3284 {
3285 	char clevel[16];
3286 	ssize_t rv = len;
3287 	struct mdk_personality *pers;
3288 	long level;
3289 	void *priv;
3290 	mdk_rdev_t *rdev;
3291 
3292 	if (mddev->pers == NULL) {
3293 		if (len == 0)
3294 			return 0;
3295 		if (len >= sizeof(mddev->clevel))
3296 			return -ENOSPC;
3297 		strncpy(mddev->clevel, buf, len);
3298 		if (mddev->clevel[len-1] == '\n')
3299 			len--;
3300 		mddev->clevel[len] = 0;
3301 		mddev->level = LEVEL_NONE;
3302 		return rv;
3303 	}
3304 
3305 	/* request to change the personality.  Need to ensure:
3306 	 *  - array is not engaged in resync/recovery/reshape
3307 	 *  - old personality can be suspended
3308 	 *  - new personality will access other array.
3309 	 */
3310 
3311 	if (mddev->sync_thread ||
3312 	    mddev->reshape_position != MaxSector ||
3313 	    mddev->sysfs_active)
3314 		return -EBUSY;
3315 
3316 	if (!mddev->pers->quiesce) {
3317 		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3318 		       mdname(mddev), mddev->pers->name);
3319 		return -EINVAL;
3320 	}
3321 
3322 	/* Now find the new personality */
3323 	if (len == 0 || len >= sizeof(clevel))
3324 		return -EINVAL;
3325 	strncpy(clevel, buf, len);
3326 	if (clevel[len-1] == '\n')
3327 		len--;
3328 	clevel[len] = 0;
3329 	if (strict_strtol(clevel, 10, &level))
3330 		level = LEVEL_NONE;
3331 
3332 	if (request_module("md-%s", clevel) != 0)
3333 		request_module("md-level-%s", clevel);
3334 	spin_lock(&pers_lock);
3335 	pers = find_pers(level, clevel);
3336 	if (!pers || !try_module_get(pers->owner)) {
3337 		spin_unlock(&pers_lock);
3338 		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3339 		return -EINVAL;
3340 	}
3341 	spin_unlock(&pers_lock);
3342 
3343 	if (pers == mddev->pers) {
3344 		/* Nothing to do! */
3345 		module_put(pers->owner);
3346 		return rv;
3347 	}
3348 	if (!pers->takeover) {
3349 		module_put(pers->owner);
3350 		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3351 		       mdname(mddev), clevel);
3352 		return -EINVAL;
3353 	}
3354 
3355 	list_for_each_entry(rdev, &mddev->disks, same_set)
3356 		rdev->new_raid_disk = rdev->raid_disk;
3357 
3358 	/* ->takeover must set new_* and/or delta_disks
3359 	 * if it succeeds, and may set them when it fails.
3360 	 */
3361 	priv = pers->takeover(mddev);
3362 	if (IS_ERR(priv)) {
3363 		mddev->new_level = mddev->level;
3364 		mddev->new_layout = mddev->layout;
3365 		mddev->new_chunk_sectors = mddev->chunk_sectors;
3366 		mddev->raid_disks -= mddev->delta_disks;
3367 		mddev->delta_disks = 0;
3368 		module_put(pers->owner);
3369 		printk(KERN_WARNING "md: %s: %s would not accept array\n",
3370 		       mdname(mddev), clevel);
3371 		return PTR_ERR(priv);
3372 	}
3373 
3374 	/* Looks like we have a winner */
3375 	mddev_suspend(mddev);
3376 	mddev->pers->stop(mddev);
3377 
3378 	if (mddev->pers->sync_request == NULL &&
3379 	    pers->sync_request != NULL) {
3380 		/* need to add the md_redundancy_group */
3381 		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3382 			printk(KERN_WARNING
3383 			       "md: cannot register extra attributes for %s\n",
3384 			       mdname(mddev));
3385 		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
3386 	}
3387 	if (mddev->pers->sync_request != NULL &&
3388 	    pers->sync_request == NULL) {
3389 		/* need to remove the md_redundancy_group */
3390 		if (mddev->to_remove == NULL)
3391 			mddev->to_remove = &md_redundancy_group;
3392 	}
3393 
3394 	if (mddev->pers->sync_request == NULL &&
3395 	    mddev->external) {
3396 		/* We are converting from a no-redundancy array
3397 		 * to a redundancy array and metadata is managed
3398 		 * externally so we need to be sure that writes
3399 		 * won't block due to a need to transition
3400 		 *      clean->dirty
3401 		 * until external management is started.
3402 		 */
3403 		mddev->in_sync = 0;
3404 		mddev->safemode_delay = 0;
3405 		mddev->safemode = 0;
3406 	}
3407 
3408 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3409 		if (rdev->raid_disk < 0)
3410 			continue;
3411 		if (rdev->new_raid_disk >= mddev->raid_disks)
3412 			rdev->new_raid_disk = -1;
3413 		if (rdev->new_raid_disk == rdev->raid_disk)
3414 			continue;
3415 		sysfs_unlink_rdev(mddev, rdev);
3416 	}
3417 	list_for_each_entry(rdev, &mddev->disks, same_set) {
3418 		if (rdev->raid_disk < 0)
3419 			continue;
3420 		if (rdev->new_raid_disk == rdev->raid_disk)
3421 			continue;
3422 		rdev->raid_disk = rdev->new_raid_disk;
3423 		if (rdev->raid_disk < 0)
3424 			clear_bit(In_sync, &rdev->flags);
3425 		else {
3426 			if (sysfs_link_rdev(mddev, rdev))
3427 				printk(KERN_WARNING "md: cannot register rd%d"
3428 				       " for %s after level change\n",
3429 				       rdev->raid_disk, mdname(mddev));
3430 		}
3431 	}
3432 
3433 	module_put(mddev->pers->owner);
3434 	mddev->pers = pers;
3435 	mddev->private = priv;
3436 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3437 	mddev->level = mddev->new_level;
3438 	mddev->layout = mddev->new_layout;
3439 	mddev->chunk_sectors = mddev->new_chunk_sectors;
3440 	mddev->delta_disks = 0;
3441 	mddev->degraded = 0;
3442 	if (mddev->pers->sync_request == NULL) {
3443 		/* this is now an array without redundancy, so
3444 		 * it must always be in_sync
3445 		 */
3446 		mddev->in_sync = 1;
3447 		del_timer_sync(&mddev->safemode_timer);
3448 	}
3449 	pers->run(mddev);
3450 	mddev_resume(mddev);
3451 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
3452 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3453 	md_wakeup_thread(mddev->thread);
3454 	sysfs_notify(&mddev->kobj, NULL, "level");
3455 	md_new_event(mddev);
3456 	return rv;
3457 }
3458 
3459 static struct md_sysfs_entry md_level =
3460 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3461 
3462 
3463 static ssize_t
3464 layout_show(mddev_t *mddev, char *page)
3465 {
3466 	/* just a number, not meaningful for all levels */
3467 	if (mddev->reshape_position != MaxSector &&
3468 	    mddev->layout != mddev->new_layout)
3469 		return sprintf(page, "%d (%d)\n",
3470 			       mddev->new_layout, mddev->layout);
3471 	return sprintf(page, "%d\n", mddev->layout);
3472 }
3473 
3474 static ssize_t
3475 layout_store(mddev_t *mddev, const char *buf, size_t len)
3476 {
3477 	char *e;
3478 	unsigned long n = simple_strtoul(buf, &e, 10);
3479 
3480 	if (!*buf || (*e && *e != '\n'))
3481 		return -EINVAL;
3482 
3483 	if (mddev->pers) {
3484 		int err;
3485 		if (mddev->pers->check_reshape == NULL)
3486 			return -EBUSY;
3487 		mddev->new_layout = n;
3488 		err = mddev->pers->check_reshape(mddev);
3489 		if (err) {
3490 			mddev->new_layout = mddev->layout;
3491 			return err;
3492 		}
3493 	} else {
3494 		mddev->new_layout = n;
3495 		if (mddev->reshape_position == MaxSector)
3496 			mddev->layout = n;
3497 	}
3498 	return len;
3499 }
3500 static struct md_sysfs_entry md_layout =
3501 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3502 
3503 
3504 static ssize_t
3505 raid_disks_show(mddev_t *mddev, char *page)
3506 {
3507 	if (mddev->raid_disks == 0)
3508 		return 0;
3509 	if (mddev->reshape_position != MaxSector &&
3510 	    mddev->delta_disks != 0)
3511 		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3512 			       mddev->raid_disks - mddev->delta_disks);
3513 	return sprintf(page, "%d\n", mddev->raid_disks);
3514 }
3515 
3516 static int update_raid_disks(mddev_t *mddev, int raid_disks);
3517 
3518 static ssize_t
3519 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
3520 {
3521 	char *e;
3522 	int rv = 0;
3523 	unsigned long n = simple_strtoul(buf, &e, 10);
3524 
3525 	if (!*buf || (*e && *e != '\n'))
3526 		return -EINVAL;
3527 
3528 	if (mddev->pers)
3529 		rv = update_raid_disks(mddev, n);
3530 	else if (mddev->reshape_position != MaxSector) {
3531 		int olddisks = mddev->raid_disks - mddev->delta_disks;
3532 		mddev->delta_disks = n - olddisks;
3533 		mddev->raid_disks = n;
3534 	} else
3535 		mddev->raid_disks = n;
3536 	return rv ? rv : len;
3537 }
3538 static struct md_sysfs_entry md_raid_disks =
3539 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3540 
3541 static ssize_t
3542 chunk_size_show(mddev_t *mddev, char *page)
3543 {
3544 	if (mddev->reshape_position != MaxSector &&
3545 	    mddev->chunk_sectors != mddev->new_chunk_sectors)
3546 		return sprintf(page, "%d (%d)\n",
3547 			       mddev->new_chunk_sectors << 9,
3548 			       mddev->chunk_sectors << 9);
3549 	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3550 }
3551 
3552 static ssize_t
3553 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
3554 {
3555 	char *e;
3556 	unsigned long n = simple_strtoul(buf, &e, 10);
3557 
3558 	if (!*buf || (*e && *e != '\n'))
3559 		return -EINVAL;
3560 
3561 	if (mddev->pers) {
3562 		int err;
3563 		if (mddev->pers->check_reshape == NULL)
3564 			return -EBUSY;
3565 		mddev->new_chunk_sectors = n >> 9;
3566 		err = mddev->pers->check_reshape(mddev);
3567 		if (err) {
3568 			mddev->new_chunk_sectors = mddev->chunk_sectors;
3569 			return err;
3570 		}
3571 	} else {
3572 		mddev->new_chunk_sectors = n >> 9;
3573 		if (mddev->reshape_position == MaxSector)
3574 			mddev->chunk_sectors = n >> 9;
3575 	}
3576 	return len;
3577 }
3578 static struct md_sysfs_entry md_chunk_size =
3579 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3580 
3581 static ssize_t
3582 resync_start_show(mddev_t *mddev, char *page)
3583 {
3584 	if (mddev->recovery_cp == MaxSector)
3585 		return sprintf(page, "none\n");
3586 	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3587 }
3588 
3589 static ssize_t
3590 resync_start_store(mddev_t *mddev, const char *buf, size_t len)
3591 {
3592 	char *e;
3593 	unsigned long long n = simple_strtoull(buf, &e, 10);
3594 
3595 	if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3596 		return -EBUSY;
3597 	if (cmd_match(buf, "none"))
3598 		n = MaxSector;
3599 	else if (!*buf || (*e && *e != '\n'))
3600 		return -EINVAL;
3601 
3602 	mddev->recovery_cp = n;
3603 	return len;
3604 }
3605 static struct md_sysfs_entry md_resync_start =
3606 __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
3607 
3608 /*
3609  * The array state can be:
3610  *
3611  * clear
3612  *     No devices, no size, no level
3613  *     Equivalent to STOP_ARRAY ioctl
3614  * inactive
3615  *     May have some settings, but array is not active
3616  *        all IO results in error
3617  *     When written, doesn't tear down array, but just stops it
3618  * suspended (not supported yet)
3619  *     All IO requests will block. The array can be reconfigured.
3620  *     Writing this, if accepted, will block until array is quiescent
3621  * readonly
3622  *     no resync can happen.  no superblocks get written.
3623  *     write requests fail
3624  * read-auto
3625  *     like readonly, but behaves like 'clean' on a write request.
3626  *
3627  * clean - no pending writes, but otherwise active.
3628  *     When written to inactive array, starts without resync
3629  *     If a write request arrives then
3630  *       if metadata is known, mark 'dirty' and switch to 'active'.
3631  *       if not known, block and switch to write-pending
3632  *     If written to an active array that has pending writes, then fails.
3633  * active
3634  *     fully active: IO and resync can be happening.
3635  *     When written to inactive array, starts with resync
3636  *
3637  * write-pending
3638  *     clean, but writes are blocked waiting for 'active' to be written.
3639  *
3640  * active-idle
3641  *     like active, but no writes have been seen for a while (100msec).
3642  *
3643  */
3644 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3645 		   write_pending, active_idle, bad_word};
3646 static char *array_states[] = {
3647 	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3648 	"write-pending", "active-idle", NULL };
3649 
3650 static int match_word(const char *word, char **list)
3651 {
3652 	int n;
3653 	for (n=0; list[n]; n++)
3654 		if (cmd_match(word, list[n]))
3655 			break;
3656 	return n;
3657 }
3658 
3659 static ssize_t
3660 array_state_show(mddev_t *mddev, char *page)
3661 {
3662 	enum array_state st = inactive;
3663 
3664 	if (mddev->pers)
3665 		switch(mddev->ro) {
3666 		case 1:
3667 			st = readonly;
3668 			break;
3669 		case 2:
3670 			st = read_auto;
3671 			break;
3672 		case 0:
3673 			if (mddev->in_sync)
3674 				st = clean;
3675 			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3676 				st = write_pending;
3677 			else if (mddev->safemode)
3678 				st = active_idle;
3679 			else
3680 				st = active;
3681 		}
3682 	else {
3683 		if (list_empty(&mddev->disks) &&
3684 		    mddev->raid_disks == 0 &&
3685 		    mddev->dev_sectors == 0)
3686 			st = clear;
3687 		else
3688 			st = inactive;
3689 	}
3690 	return sprintf(page, "%s\n", array_states[st]);
3691 }
3692 
3693 static int do_md_stop(mddev_t * mddev, int ro, int is_open);
3694 static int md_set_readonly(mddev_t * mddev, int is_open);
3695 static int do_md_run(mddev_t * mddev);
3696 static int restart_array(mddev_t *mddev);
3697 
3698 static ssize_t
3699 array_state_store(mddev_t *mddev, const char *buf, size_t len)
3700 {
3701 	int err = -EINVAL;
3702 	enum array_state st = match_word(buf, array_states);
3703 	switch(st) {
3704 	case bad_word:
3705 		break;
3706 	case clear:
3707 		/* stopping an active array */
3708 		if (atomic_read(&mddev->openers) > 0)
3709 			return -EBUSY;
3710 		err = do_md_stop(mddev, 0, 0);
3711 		break;
3712 	case inactive:
3713 		/* stopping an active array */
3714 		if (mddev->pers) {
3715 			if (atomic_read(&mddev->openers) > 0)
3716 				return -EBUSY;
3717 			err = do_md_stop(mddev, 2, 0);
3718 		} else
3719 			err = 0; /* already inactive */
3720 		break;
3721 	case suspended:
3722 		break; /* not supported yet */
3723 	case readonly:
3724 		if (mddev->pers)
3725 			err = md_set_readonly(mddev, 0);
3726 		else {
3727 			mddev->ro = 1;
3728 			set_disk_ro(mddev->gendisk, 1);
3729 			err = do_md_run(mddev);
3730 		}
3731 		break;
3732 	case read_auto:
3733 		if (mddev->pers) {
3734 			if (mddev->ro == 0)
3735 				err = md_set_readonly(mddev, 0);
3736 			else if (mddev->ro == 1)
3737 				err = restart_array(mddev);
3738 			if (err == 0) {
3739 				mddev->ro = 2;
3740 				set_disk_ro(mddev->gendisk, 0);
3741 			}
3742 		} else {
3743 			mddev->ro = 2;
3744 			err = do_md_run(mddev);
3745 		}
3746 		break;
3747 	case clean:
3748 		if (mddev->pers) {
3749 			restart_array(mddev);
3750 			spin_lock_irq(&mddev->write_lock);
3751 			if (atomic_read(&mddev->writes_pending) == 0) {
3752 				if (mddev->in_sync == 0) {
3753 					mddev->in_sync = 1;
3754 					if (mddev->safemode == 1)
3755 						mddev->safemode = 0;
3756 					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3757 				}
3758 				err = 0;
3759 			} else
3760 				err = -EBUSY;
3761 			spin_unlock_irq(&mddev->write_lock);
3762 		} else
3763 			err = -EINVAL;
3764 		break;
3765 	case active:
3766 		if (mddev->pers) {
3767 			restart_array(mddev);
3768 			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3769 			wake_up(&mddev->sb_wait);
3770 			err = 0;
3771 		} else {
3772 			mddev->ro = 0;
3773 			set_disk_ro(mddev->gendisk, 0);
3774 			err = do_md_run(mddev);
3775 		}
3776 		break;
3777 	case write_pending:
3778 	case active_idle:
3779 		/* these cannot be set */
3780 		break;
3781 	}
3782 	if (err)
3783 		return err;
3784 	else {
3785 		sysfs_notify_dirent_safe(mddev->sysfs_state);
3786 		return len;
3787 	}
3788 }
3789 static struct md_sysfs_entry md_array_state =
3790 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
3791 
3792 static ssize_t
3793 max_corrected_read_errors_show(mddev_t *mddev, char *page) {
3794 	return sprintf(page, "%d\n",
3795 		       atomic_read(&mddev->max_corr_read_errors));
3796 }
3797 
3798 static ssize_t
3799 max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
3800 {
3801 	char *e;
3802 	unsigned long n = simple_strtoul(buf, &e, 10);
3803 
3804 	if (*buf && (*e == 0 || *e == '\n')) {
3805 		atomic_set(&mddev->max_corr_read_errors, n);
3806 		return len;
3807 	}
3808 	return -EINVAL;
3809 }
3810 
3811 static struct md_sysfs_entry max_corr_read_errors =
3812 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
3813 	max_corrected_read_errors_store);
3814 
3815 static ssize_t
3816 null_show(mddev_t *mddev, char *page)
3817 {
3818 	return -EINVAL;
3819 }
3820 
3821 static ssize_t
3822 new_dev_store(mddev_t *mddev, const char *buf, size_t len)
3823 {
3824 	/* buf must be %d:%d\n? giving major and minor numbers */
3825 	/* The new device is added to the array.
3826 	 * If the array has a persistent superblock, we read the
3827 	 * superblock to initialise info and check validity.
3828 	 * Otherwise, only checking done is that in bind_rdev_to_array,
3829 	 * which mainly checks size.
3830 	 */
3831 	char *e;
3832 	int major = simple_strtoul(buf, &e, 10);
3833 	int minor;
3834 	dev_t dev;
3835 	mdk_rdev_t *rdev;
3836 	int err;
3837 
3838 	if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
3839 		return -EINVAL;
3840 	minor = simple_strtoul(e+1, &e, 10);
3841 	if (*e && *e != '\n')
3842 		return -EINVAL;
3843 	dev = MKDEV(major, minor);
3844 	if (major != MAJOR(dev) ||
3845 	    minor != MINOR(dev))
3846 		return -EOVERFLOW;
3847 
3848 
3849 	if (mddev->persistent) {
3850 		rdev = md_import_device(dev, mddev->major_version,
3851 					mddev->minor_version);
3852 		if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
3853 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
3854 						       mdk_rdev_t, same_set);
3855 			err = super_types[mddev->major_version]
3856 				.load_super(rdev, rdev0, mddev->minor_version);
3857 			if (err < 0)
3858 				goto out;
3859 		}
3860 	} else if (mddev->external)
3861 		rdev = md_import_device(dev, -2, -1);
3862 	else
3863 		rdev = md_import_device(dev, -1, -1);
3864 
3865 	if (IS_ERR(rdev))
3866 		return PTR_ERR(rdev);
3867 	err = bind_rdev_to_array(rdev, mddev);
3868  out:
3869 	if (err)
3870 		export_rdev(rdev);
3871 	return err ? err : len;
3872 }
3873 
3874 static struct md_sysfs_entry md_new_device =
3875 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
3876 
3877 static ssize_t
3878 bitmap_store(mddev_t *mddev, const char *buf, size_t len)
3879 {
3880 	char *end;
3881 	unsigned long chunk, end_chunk;
3882 
3883 	if (!mddev->bitmap)
3884 		goto out;
3885 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
3886 	while (*buf) {
3887 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
3888 		if (buf == end) break;
3889 		if (*end == '-') { /* range */
3890 			buf = end + 1;
3891 			end_chunk = simple_strtoul(buf, &end, 0);
3892 			if (buf == end) break;
3893 		}
3894 		if (*end && !isspace(*end)) break;
3895 		bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
3896 		buf = skip_spaces(end);
3897 	}
3898 	bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
3899 out:
3900 	return len;
3901 }
3902 
3903 static struct md_sysfs_entry md_bitmap =
3904 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
3905 
3906 static ssize_t
3907 size_show(mddev_t *mddev, char *page)
3908 {
3909 	return sprintf(page, "%llu\n",
3910 		(unsigned long long)mddev->dev_sectors / 2);
3911 }
3912 
3913 static int update_size(mddev_t *mddev, sector_t num_sectors);
3914 
3915 static ssize_t
3916 size_store(mddev_t *mddev, const char *buf, size_t len)
3917 {
3918 	/* If array is inactive, we can reduce the component size, but
3919 	 * not increase it (except from 0).
3920 	 * If array is active, we can try an on-line resize
3921 	 */
3922 	sector_t sectors;
3923 	int err = strict_blocks_to_sectors(buf, &sectors);
3924 
3925 	if (err < 0)
3926 		return err;
3927 	if (mddev->pers) {
3928 		err = update_size(mddev, sectors);
3929 		md_update_sb(mddev, 1);
3930 	} else {
3931 		if (mddev->dev_sectors == 0 ||
3932 		    mddev->dev_sectors > sectors)
3933 			mddev->dev_sectors = sectors;
3934 		else
3935 			err = -ENOSPC;
3936 	}
3937 	return err ? err : len;
3938 }
3939 
3940 static struct md_sysfs_entry md_size =
3941 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
3942 
3943 
3944 /* Metdata version.
3945  * This is one of
3946  *   'none' for arrays with no metadata (good luck...)
3947  *   'external' for arrays with externally managed metadata,
3948  * or N.M for internally known formats
3949  */
3950 static ssize_t
3951 metadata_show(mddev_t *mddev, char *page)
3952 {
3953 	if (mddev->persistent)
3954 		return sprintf(page, "%d.%d\n",
3955 			       mddev->major_version, mddev->minor_version);
3956 	else if (mddev->external)
3957 		return sprintf(page, "external:%s\n", mddev->metadata_type);
3958 	else
3959 		return sprintf(page, "none\n");
3960 }
3961 
3962 static ssize_t
3963 metadata_store(mddev_t *mddev, const char *buf, size_t len)
3964 {
3965 	int major, minor;
3966 	char *e;
3967 	/* Changing the details of 'external' metadata is
3968 	 * always permitted.  Otherwise there must be
3969 	 * no devices attached to the array.
3970 	 */
3971 	if (mddev->external && strncmp(buf, "external:", 9) == 0)
3972 		;
3973 	else if (!list_empty(&mddev->disks))
3974 		return -EBUSY;
3975 
3976 	if (cmd_match(buf, "none")) {
3977 		mddev->persistent = 0;
3978 		mddev->external = 0;
3979 		mddev->major_version = 0;
3980 		mddev->minor_version = 90;
3981 		return len;
3982 	}
3983 	if (strncmp(buf, "external:", 9) == 0) {
3984 		size_t namelen = len-9;
3985 		if (namelen >= sizeof(mddev->metadata_type))
3986 			namelen = sizeof(mddev->metadata_type)-1;
3987 		strncpy(mddev->metadata_type, buf+9, namelen);
3988 		mddev->metadata_type[namelen] = 0;
3989 		if (namelen && mddev->metadata_type[namelen-1] == '\n')
3990 			mddev->metadata_type[--namelen] = 0;
3991 		mddev->persistent = 0;
3992 		mddev->external = 1;
3993 		mddev->major_version = 0;
3994 		mddev->minor_version = 90;
3995 		return len;
3996 	}
3997 	major = simple_strtoul(buf, &e, 10);
3998 	if (e==buf || *e != '.')
3999 		return -EINVAL;
4000 	buf = e+1;
4001 	minor = simple_strtoul(buf, &e, 10);
4002 	if (e==buf || (*e && *e != '\n') )
4003 		return -EINVAL;
4004 	if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4005 		return -ENOENT;
4006 	mddev->major_version = major;
4007 	mddev->minor_version = minor;
4008 	mddev->persistent = 1;
4009 	mddev->external = 0;
4010 	return len;
4011 }
4012 
4013 static struct md_sysfs_entry md_metadata =
4014 __ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4015 
4016 static ssize_t
4017 action_show(mddev_t *mddev, char *page)
4018 {
4019 	char *type = "idle";
4020 	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4021 		type = "frozen";
4022 	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4023 	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
4024 		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4025 			type = "reshape";
4026 		else if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4027 			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
4028 				type = "resync";
4029 			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
4030 				type = "check";
4031 			else
4032 				type = "repair";
4033 		} else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
4034 			type = "recover";
4035 	}
4036 	return sprintf(page, "%s\n", type);
4037 }
4038 
4039 static void reap_sync_thread(mddev_t *mddev);
4040 
4041 static ssize_t
4042 action_store(mddev_t *mddev, const char *page, size_t len)
4043 {
4044 	if (!mddev->pers || !mddev->pers->sync_request)
4045 		return -EINVAL;
4046 
4047 	if (cmd_match(page, "frozen"))
4048 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4049 	else
4050 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4051 
4052 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4053 		if (mddev->sync_thread) {
4054 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4055 			reap_sync_thread(mddev);
4056 		}
4057 	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4058 		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
4059 		return -EBUSY;
4060 	else if (cmd_match(page, "resync"))
4061 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4062 	else if (cmd_match(page, "recover")) {
4063 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4064 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4065 	} else if (cmd_match(page, "reshape")) {
4066 		int err;
4067 		if (mddev->pers->start_reshape == NULL)
4068 			return -EINVAL;
4069 		err = mddev->pers->start_reshape(mddev);
4070 		if (err)
4071 			return err;
4072 		sysfs_notify(&mddev->kobj, NULL, "degraded");
4073 	} else {
4074 		if (cmd_match(page, "check"))
4075 			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4076 		else if (!cmd_match(page, "repair"))
4077 			return -EINVAL;
4078 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4079 		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4080 	}
4081 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4082 	md_wakeup_thread(mddev->thread);
4083 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4084 	return len;
4085 }
4086 
4087 static ssize_t
4088 mismatch_cnt_show(mddev_t *mddev, char *page)
4089 {
4090 	return sprintf(page, "%llu\n",
4091 		       (unsigned long long) mddev->resync_mismatches);
4092 }
4093 
4094 static struct md_sysfs_entry md_scan_mode =
4095 __ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4096 
4097 
4098 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4099 
4100 static ssize_t
4101 sync_min_show(mddev_t *mddev, char *page)
4102 {
4103 	return sprintf(page, "%d (%s)\n", speed_min(mddev),
4104 		       mddev->sync_speed_min ? "local": "system");
4105 }
4106 
4107 static ssize_t
4108 sync_min_store(mddev_t *mddev, const char *buf, size_t len)
4109 {
4110 	int min;
4111 	char *e;
4112 	if (strncmp(buf, "system", 6)==0) {
4113 		mddev->sync_speed_min = 0;
4114 		return len;
4115 	}
4116 	min = simple_strtoul(buf, &e, 10);
4117 	if (buf == e || (*e && *e != '\n') || min <= 0)
4118 		return -EINVAL;
4119 	mddev->sync_speed_min = min;
4120 	return len;
4121 }
4122 
4123 static struct md_sysfs_entry md_sync_min =
4124 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4125 
4126 static ssize_t
4127 sync_max_show(mddev_t *mddev, char *page)
4128 {
4129 	return sprintf(page, "%d (%s)\n", speed_max(mddev),
4130 		       mddev->sync_speed_max ? "local": "system");
4131 }
4132 
4133 static ssize_t
4134 sync_max_store(mddev_t *mddev, const char *buf, size_t len)
4135 {
4136 	int max;
4137 	char *e;
4138 	if (strncmp(buf, "system", 6)==0) {
4139 		mddev->sync_speed_max = 0;
4140 		return len;
4141 	}
4142 	max = simple_strtoul(buf, &e, 10);
4143 	if (buf == e || (*e && *e != '\n') || max <= 0)
4144 		return -EINVAL;
4145 	mddev->sync_speed_max = max;
4146 	return len;
4147 }
4148 
4149 static struct md_sysfs_entry md_sync_max =
4150 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4151 
4152 static ssize_t
4153 degraded_show(mddev_t *mddev, char *page)
4154 {
4155 	return sprintf(page, "%d\n", mddev->degraded);
4156 }
4157 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4158 
4159 static ssize_t
4160 sync_force_parallel_show(mddev_t *mddev, char *page)
4161 {
4162 	return sprintf(page, "%d\n", mddev->parallel_resync);
4163 }
4164 
4165 static ssize_t
4166 sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
4167 {
4168 	long n;
4169 
4170 	if (strict_strtol(buf, 10, &n))
4171 		return -EINVAL;
4172 
4173 	if (n != 0 && n != 1)
4174 		return -EINVAL;
4175 
4176 	mddev->parallel_resync = n;
4177 
4178 	if (mddev->sync_thread)
4179 		wake_up(&resync_wait);
4180 
4181 	return len;
4182 }
4183 
4184 /* force parallel resync, even with shared block devices */
4185 static struct md_sysfs_entry md_sync_force_parallel =
4186 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4187        sync_force_parallel_show, sync_force_parallel_store);
4188 
4189 static ssize_t
4190 sync_speed_show(mddev_t *mddev, char *page)
4191 {
4192 	unsigned long resync, dt, db;
4193 	if (mddev->curr_resync == 0)
4194 		return sprintf(page, "none\n");
4195 	resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4196 	dt = (jiffies - mddev->resync_mark) / HZ;
4197 	if (!dt) dt++;
4198 	db = resync - mddev->resync_mark_cnt;
4199 	return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4200 }
4201 
4202 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4203 
4204 static ssize_t
4205 sync_completed_show(mddev_t *mddev, char *page)
4206 {
4207 	unsigned long long max_sectors, resync;
4208 
4209 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4210 		return sprintf(page, "none\n");
4211 
4212 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
4213 		max_sectors = mddev->resync_max_sectors;
4214 	else
4215 		max_sectors = mddev->dev_sectors;
4216 
4217 	resync = mddev->curr_resync_completed;
4218 	return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4219 }
4220 
4221 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
4222 
4223 static ssize_t
4224 min_sync_show(mddev_t *mddev, char *page)
4225 {
4226 	return sprintf(page, "%llu\n",
4227 		       (unsigned long long)mddev->resync_min);
4228 }
4229 static ssize_t
4230 min_sync_store(mddev_t *mddev, const char *buf, size_t len)
4231 {
4232 	unsigned long long min;
4233 	if (strict_strtoull(buf, 10, &min))
4234 		return -EINVAL;
4235 	if (min > mddev->resync_max)
4236 		return -EINVAL;
4237 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4238 		return -EBUSY;
4239 
4240 	/* Must be a multiple of chunk_size */
4241 	if (mddev->chunk_sectors) {
4242 		sector_t temp = min;
4243 		if (sector_div(temp, mddev->chunk_sectors))
4244 			return -EINVAL;
4245 	}
4246 	mddev->resync_min = min;
4247 
4248 	return len;
4249 }
4250 
4251 static struct md_sysfs_entry md_min_sync =
4252 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4253 
4254 static ssize_t
4255 max_sync_show(mddev_t *mddev, char *page)
4256 {
4257 	if (mddev->resync_max == MaxSector)
4258 		return sprintf(page, "max\n");
4259 	else
4260 		return sprintf(page, "%llu\n",
4261 			       (unsigned long long)mddev->resync_max);
4262 }
4263 static ssize_t
4264 max_sync_store(mddev_t *mddev, const char *buf, size_t len)
4265 {
4266 	if (strncmp(buf, "max", 3) == 0)
4267 		mddev->resync_max = MaxSector;
4268 	else {
4269 		unsigned long long max;
4270 		if (strict_strtoull(buf, 10, &max))
4271 			return -EINVAL;
4272 		if (max < mddev->resync_min)
4273 			return -EINVAL;
4274 		if (max < mddev->resync_max &&
4275 		    mddev->ro == 0 &&
4276 		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4277 			return -EBUSY;
4278 
4279 		/* Must be a multiple of chunk_size */
4280 		if (mddev->chunk_sectors) {
4281 			sector_t temp = max;
4282 			if (sector_div(temp, mddev->chunk_sectors))
4283 				return -EINVAL;
4284 		}
4285 		mddev->resync_max = max;
4286 	}
4287 	wake_up(&mddev->recovery_wait);
4288 	return len;
4289 }
4290 
4291 static struct md_sysfs_entry md_max_sync =
4292 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4293 
4294 static ssize_t
4295 suspend_lo_show(mddev_t *mddev, char *page)
4296 {
4297 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4298 }
4299 
4300 static ssize_t
4301 suspend_lo_store(mddev_t *mddev, const char *buf, size_t len)
4302 {
4303 	char *e;
4304 	unsigned long long new = simple_strtoull(buf, &e, 10);
4305 	unsigned long long old = mddev->suspend_lo;
4306 
4307 	if (mddev->pers == NULL ||
4308 	    mddev->pers->quiesce == NULL)
4309 		return -EINVAL;
4310 	if (buf == e || (*e && *e != '\n'))
4311 		return -EINVAL;
4312 
4313 	mddev->suspend_lo = new;
4314 	if (new >= old)
4315 		/* Shrinking suspended region */
4316 		mddev->pers->quiesce(mddev, 2);
4317 	else {
4318 		/* Expanding suspended region - need to wait */
4319 		mddev->pers->quiesce(mddev, 1);
4320 		mddev->pers->quiesce(mddev, 0);
4321 	}
4322 	return len;
4323 }
4324 static struct md_sysfs_entry md_suspend_lo =
4325 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4326 
4327 
4328 static ssize_t
4329 suspend_hi_show(mddev_t *mddev, char *page)
4330 {
4331 	return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4332 }
4333 
4334 static ssize_t
4335 suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
4336 {
4337 	char *e;
4338 	unsigned long long new = simple_strtoull(buf, &e, 10);
4339 	unsigned long long old = mddev->suspend_hi;
4340 
4341 	if (mddev->pers == NULL ||
4342 	    mddev->pers->quiesce == NULL)
4343 		return -EINVAL;
4344 	if (buf == e || (*e && *e != '\n'))
4345 		return -EINVAL;
4346 
4347 	mddev->suspend_hi = new;
4348 	if (new <= old)
4349 		/* Shrinking suspended region */
4350 		mddev->pers->quiesce(mddev, 2);
4351 	else {
4352 		/* Expanding suspended region - need to wait */
4353 		mddev->pers->quiesce(mddev, 1);
4354 		mddev->pers->quiesce(mddev, 0);
4355 	}
4356 	return len;
4357 }
4358 static struct md_sysfs_entry md_suspend_hi =
4359 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4360 
4361 static ssize_t
4362 reshape_position_show(mddev_t *mddev, char *page)
4363 {
4364 	if (mddev->reshape_position != MaxSector)
4365 		return sprintf(page, "%llu\n",
4366 			       (unsigned long long)mddev->reshape_position);
4367 	strcpy(page, "none\n");
4368 	return 5;
4369 }
4370 
4371 static ssize_t
4372 reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
4373 {
4374 	char *e;
4375 	unsigned long long new = simple_strtoull(buf, &e, 10);
4376 	if (mddev->pers)
4377 		return -EBUSY;
4378 	if (buf == e || (*e && *e != '\n'))
4379 		return -EINVAL;
4380 	mddev->reshape_position = new;
4381 	mddev->delta_disks = 0;
4382 	mddev->new_level = mddev->level;
4383 	mddev->new_layout = mddev->layout;
4384 	mddev->new_chunk_sectors = mddev->chunk_sectors;
4385 	return len;
4386 }
4387 
4388 static struct md_sysfs_entry md_reshape_position =
4389 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4390        reshape_position_store);
4391 
4392 static ssize_t
4393 array_size_show(mddev_t *mddev, char *page)
4394 {
4395 	if (mddev->external_size)
4396 		return sprintf(page, "%llu\n",
4397 			       (unsigned long long)mddev->array_sectors/2);
4398 	else
4399 		return sprintf(page, "default\n");
4400 }
4401 
4402 static ssize_t
4403 array_size_store(mddev_t *mddev, const char *buf, size_t len)
4404 {
4405 	sector_t sectors;
4406 
4407 	if (strncmp(buf, "default", 7) == 0) {
4408 		if (mddev->pers)
4409 			sectors = mddev->pers->size(mddev, 0, 0);
4410 		else
4411 			sectors = mddev->array_sectors;
4412 
4413 		mddev->external_size = 0;
4414 	} else {
4415 		if (strict_blocks_to_sectors(buf, &sectors) < 0)
4416 			return -EINVAL;
4417 		if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4418 			return -E2BIG;
4419 
4420 		mddev->external_size = 1;
4421 	}
4422 
4423 	mddev->array_sectors = sectors;
4424 	if (mddev->pers) {
4425 		set_capacity(mddev->gendisk, mddev->array_sectors);
4426 		revalidate_disk(mddev->gendisk);
4427 	}
4428 	return len;
4429 }
4430 
4431 static struct md_sysfs_entry md_array_size =
4432 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4433        array_size_store);
4434 
4435 static struct attribute *md_default_attrs[] = {
4436 	&md_level.attr,
4437 	&md_layout.attr,
4438 	&md_raid_disks.attr,
4439 	&md_chunk_size.attr,
4440 	&md_size.attr,
4441 	&md_resync_start.attr,
4442 	&md_metadata.attr,
4443 	&md_new_device.attr,
4444 	&md_safe_delay.attr,
4445 	&md_array_state.attr,
4446 	&md_reshape_position.attr,
4447 	&md_array_size.attr,
4448 	&max_corr_read_errors.attr,
4449 	NULL,
4450 };
4451 
4452 static struct attribute *md_redundancy_attrs[] = {
4453 	&md_scan_mode.attr,
4454 	&md_mismatches.attr,
4455 	&md_sync_min.attr,
4456 	&md_sync_max.attr,
4457 	&md_sync_speed.attr,
4458 	&md_sync_force_parallel.attr,
4459 	&md_sync_completed.attr,
4460 	&md_min_sync.attr,
4461 	&md_max_sync.attr,
4462 	&md_suspend_lo.attr,
4463 	&md_suspend_hi.attr,
4464 	&md_bitmap.attr,
4465 	&md_degraded.attr,
4466 	NULL,
4467 };
4468 static struct attribute_group md_redundancy_group = {
4469 	.name = NULL,
4470 	.attrs = md_redundancy_attrs,
4471 };
4472 
4473 
4474 static ssize_t
4475 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4476 {
4477 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4478 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4479 	ssize_t rv;
4480 
4481 	if (!entry->show)
4482 		return -EIO;
4483 	rv = mddev_lock(mddev);
4484 	if (!rv) {
4485 		rv = entry->show(mddev, page);
4486 		mddev_unlock(mddev);
4487 	}
4488 	return rv;
4489 }
4490 
4491 static ssize_t
4492 md_attr_store(struct kobject *kobj, struct attribute *attr,
4493 	      const char *page, size_t length)
4494 {
4495 	struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4496 	mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
4497 	ssize_t rv;
4498 
4499 	if (!entry->store)
4500 		return -EIO;
4501 	if (!capable(CAP_SYS_ADMIN))
4502 		return -EACCES;
4503 	rv = mddev_lock(mddev);
4504 	if (mddev->hold_active == UNTIL_IOCTL)
4505 		mddev->hold_active = 0;
4506 	if (!rv) {
4507 		rv = entry->store(mddev, page, length);
4508 		mddev_unlock(mddev);
4509 	}
4510 	return rv;
4511 }
4512 
4513 static void md_free(struct kobject *ko)
4514 {
4515 	mddev_t *mddev = container_of(ko, mddev_t, kobj);
4516 
4517 	if (mddev->sysfs_state)
4518 		sysfs_put(mddev->sysfs_state);
4519 
4520 	if (mddev->gendisk) {
4521 		del_gendisk(mddev->gendisk);
4522 		put_disk(mddev->gendisk);
4523 	}
4524 	if (mddev->queue)
4525 		blk_cleanup_queue(mddev->queue);
4526 
4527 	kfree(mddev);
4528 }
4529 
4530 static const struct sysfs_ops md_sysfs_ops = {
4531 	.show	= md_attr_show,
4532 	.store	= md_attr_store,
4533 };
4534 static struct kobj_type md_ktype = {
4535 	.release	= md_free,
4536 	.sysfs_ops	= &md_sysfs_ops,
4537 	.default_attrs	= md_default_attrs,
4538 };
4539 
4540 int mdp_major = 0;
4541 
4542 static void mddev_delayed_delete(struct work_struct *ws)
4543 {
4544 	mddev_t *mddev = container_of(ws, mddev_t, del_work);
4545 
4546 	sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4547 	kobject_del(&mddev->kobj);
4548 	kobject_put(&mddev->kobj);
4549 }
4550 
4551 static int md_alloc(dev_t dev, char *name)
4552 {
4553 	static DEFINE_MUTEX(disks_mutex);
4554 	mddev_t *mddev = mddev_find(dev);
4555 	struct gendisk *disk;
4556 	int partitioned;
4557 	int shift;
4558 	int unit;
4559 	int error;
4560 
4561 	if (!mddev)
4562 		return -ENODEV;
4563 
4564 	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4565 	shift = partitioned ? MdpMinorShift : 0;
4566 	unit = MINOR(mddev->unit) >> shift;
4567 
4568 	/* wait for any previous instance of this device to be
4569 	 * completely removed (mddev_delayed_delete).
4570 	 */
4571 	flush_workqueue(md_misc_wq);
4572 
4573 	mutex_lock(&disks_mutex);
4574 	error = -EEXIST;
4575 	if (mddev->gendisk)
4576 		goto abort;
4577 
4578 	if (name) {
4579 		/* Need to ensure that 'name' is not a duplicate.
4580 		 */
4581 		mddev_t *mddev2;
4582 		spin_lock(&all_mddevs_lock);
4583 
4584 		list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
4585 			if (mddev2->gendisk &&
4586 			    strcmp(mddev2->gendisk->disk_name, name) == 0) {
4587 				spin_unlock(&all_mddevs_lock);
4588 				goto abort;
4589 			}
4590 		spin_unlock(&all_mddevs_lock);
4591 	}
4592 
4593 	error = -ENOMEM;
4594 	mddev->queue = blk_alloc_queue(GFP_KERNEL);
4595 	if (!mddev->queue)
4596 		goto abort;
4597 	mddev->queue->queuedata = mddev;
4598 
4599 	blk_queue_make_request(mddev->queue, md_make_request);
4600 
4601 	disk = alloc_disk(1 << shift);
4602 	if (!disk) {
4603 		blk_cleanup_queue(mddev->queue);
4604 		mddev->queue = NULL;
4605 		goto abort;
4606 	}
4607 	disk->major = MAJOR(mddev->unit);
4608 	disk->first_minor = unit << shift;
4609 	if (name)
4610 		strcpy(disk->disk_name, name);
4611 	else if (partitioned)
4612 		sprintf(disk->disk_name, "md_d%d", unit);
4613 	else
4614 		sprintf(disk->disk_name, "md%d", unit);
4615 	disk->fops = &md_fops;
4616 	disk->private_data = mddev;
4617 	disk->queue = mddev->queue;
4618 	blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
4619 	/* Allow extended partitions.  This makes the
4620 	 * 'mdp' device redundant, but we can't really
4621 	 * remove it now.
4622 	 */
4623 	disk->flags |= GENHD_FL_EXT_DEVT;
4624 	mddev->gendisk = disk;
4625 	/* As soon as we call add_disk(), another thread could get
4626 	 * through to md_open, so make sure it doesn't get too far
4627 	 */
4628 	mutex_lock(&mddev->open_mutex);
4629 	add_disk(disk);
4630 
4631 	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
4632 				     &disk_to_dev(disk)->kobj, "%s", "md");
4633 	if (error) {
4634 		/* This isn't possible, but as kobject_init_and_add is marked
4635 		 * __must_check, we must do something with the result
4636 		 */
4637 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
4638 		       disk->disk_name);
4639 		error = 0;
4640 	}
4641 	if (mddev->kobj.sd &&
4642 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
4643 		printk(KERN_DEBUG "pointless warning\n");
4644 	mutex_unlock(&mddev->open_mutex);
4645  abort:
4646 	mutex_unlock(&disks_mutex);
4647 	if (!error && mddev->kobj.sd) {
4648 		kobject_uevent(&mddev->kobj, KOBJ_ADD);
4649 		mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
4650 	}
4651 	mddev_put(mddev);
4652 	return error;
4653 }
4654 
4655 static struct kobject *md_probe(dev_t dev, int *part, void *data)
4656 {
4657 	md_alloc(dev, NULL);
4658 	return NULL;
4659 }
4660 
4661 static int add_named_array(const char *val, struct kernel_param *kp)
4662 {
4663 	/* val must be "md_*" where * is not all digits.
4664 	 * We allocate an array with a large free minor number, and
4665 	 * set the name to val.  val must not already be an active name.
4666 	 */
4667 	int len = strlen(val);
4668 	char buf[DISK_NAME_LEN];
4669 
4670 	while (len && val[len-1] == '\n')
4671 		len--;
4672 	if (len >= DISK_NAME_LEN)
4673 		return -E2BIG;
4674 	strlcpy(buf, val, len+1);
4675 	if (strncmp(buf, "md_", 3) != 0)
4676 		return -EINVAL;
4677 	return md_alloc(0, buf);
4678 }
4679 
4680 static void md_safemode_timeout(unsigned long data)
4681 {
4682 	mddev_t *mddev = (mddev_t *) data;
4683 
4684 	if (!atomic_read(&mddev->writes_pending)) {
4685 		mddev->safemode = 1;
4686 		if (mddev->external)
4687 			sysfs_notify_dirent_safe(mddev->sysfs_state);
4688 	}
4689 	md_wakeup_thread(mddev->thread);
4690 }
4691 
4692 static int start_dirty_degraded;
4693 
4694 int md_run(mddev_t *mddev)
4695 {
4696 	int err;
4697 	mdk_rdev_t *rdev;
4698 	struct mdk_personality *pers;
4699 
4700 	if (list_empty(&mddev->disks))
4701 		/* cannot run an array with no devices.. */
4702 		return -EINVAL;
4703 
4704 	if (mddev->pers)
4705 		return -EBUSY;
4706 	/* Cannot run until previous stop completes properly */
4707 	if (mddev->sysfs_active)
4708 		return -EBUSY;
4709 
4710 	/*
4711 	 * Analyze all RAID superblock(s)
4712 	 */
4713 	if (!mddev->raid_disks) {
4714 		if (!mddev->persistent)
4715 			return -EINVAL;
4716 		analyze_sbs(mddev);
4717 	}
4718 
4719 	if (mddev->level != LEVEL_NONE)
4720 		request_module("md-level-%d", mddev->level);
4721 	else if (mddev->clevel[0])
4722 		request_module("md-%s", mddev->clevel);
4723 
4724 	/*
4725 	 * Drop all container device buffers, from now on
4726 	 * the only valid external interface is through the md
4727 	 * device.
4728 	 */
4729 	list_for_each_entry(rdev, &mddev->disks, same_set) {
4730 		if (test_bit(Faulty, &rdev->flags))
4731 			continue;
4732 		sync_blockdev(rdev->bdev);
4733 		invalidate_bdev(rdev->bdev);
4734 
4735 		/* perform some consistency tests on the device.
4736 		 * We don't want the data to overlap the metadata,
4737 		 * Internal Bitmap issues have been handled elsewhere.
4738 		 */
4739 		if (rdev->meta_bdev) {
4740 			/* Nothing to check */;
4741 		} else if (rdev->data_offset < rdev->sb_start) {
4742 			if (mddev->dev_sectors &&
4743 			    rdev->data_offset + mddev->dev_sectors
4744 			    > rdev->sb_start) {
4745 				printk("md: %s: data overlaps metadata\n",
4746 				       mdname(mddev));
4747 				return -EINVAL;
4748 			}
4749 		} else {
4750 			if (rdev->sb_start + rdev->sb_size/512
4751 			    > rdev->data_offset) {
4752 				printk("md: %s: metadata overlaps data\n",
4753 				       mdname(mddev));
4754 				return -EINVAL;
4755 			}
4756 		}
4757 		sysfs_notify_dirent_safe(rdev->sysfs_state);
4758 	}
4759 
4760 	if (mddev->bio_set == NULL)
4761 		mddev->bio_set = bioset_create(BIO_POOL_SIZE,
4762 					       sizeof(mddev_t *));
4763 
4764 	spin_lock(&pers_lock);
4765 	pers = find_pers(mddev->level, mddev->clevel);
4766 	if (!pers || !try_module_get(pers->owner)) {
4767 		spin_unlock(&pers_lock);
4768 		if (mddev->level != LEVEL_NONE)
4769 			printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
4770 			       mddev->level);
4771 		else
4772 			printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
4773 			       mddev->clevel);
4774 		return -EINVAL;
4775 	}
4776 	mddev->pers = pers;
4777 	spin_unlock(&pers_lock);
4778 	if (mddev->level != pers->level) {
4779 		mddev->level = pers->level;
4780 		mddev->new_level = pers->level;
4781 	}
4782 	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
4783 
4784 	if (mddev->reshape_position != MaxSector &&
4785 	    pers->start_reshape == NULL) {
4786 		/* This personality cannot handle reshaping... */
4787 		mddev->pers = NULL;
4788 		module_put(pers->owner);
4789 		return -EINVAL;
4790 	}
4791 
4792 	if (pers->sync_request) {
4793 		/* Warn if this is a potentially silly
4794 		 * configuration.
4795 		 */
4796 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
4797 		mdk_rdev_t *rdev2;
4798 		int warned = 0;
4799 
4800 		list_for_each_entry(rdev, &mddev->disks, same_set)
4801 			list_for_each_entry(rdev2, &mddev->disks, same_set) {
4802 				if (rdev < rdev2 &&
4803 				    rdev->bdev->bd_contains ==
4804 				    rdev2->bdev->bd_contains) {
4805 					printk(KERN_WARNING
4806 					       "%s: WARNING: %s appears to be"
4807 					       " on the same physical disk as"
4808 					       " %s.\n",
4809 					       mdname(mddev),
4810 					       bdevname(rdev->bdev,b),
4811 					       bdevname(rdev2->bdev,b2));
4812 					warned = 1;
4813 				}
4814 			}
4815 
4816 		if (warned)
4817 			printk(KERN_WARNING
4818 			       "True protection against single-disk"
4819 			       " failure might be compromised.\n");
4820 	}
4821 
4822 	mddev->recovery = 0;
4823 	/* may be over-ridden by personality */
4824 	mddev->resync_max_sectors = mddev->dev_sectors;
4825 
4826 	mddev->ok_start_degraded = start_dirty_degraded;
4827 
4828 	if (start_readonly && mddev->ro == 0)
4829 		mddev->ro = 2; /* read-only, but switch on first write */
4830 
4831 	err = mddev->pers->run(mddev);
4832 	if (err)
4833 		printk(KERN_ERR "md: pers->run() failed ...\n");
4834 	else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
4835 		WARN_ONCE(!mddev->external_size, "%s: default size too small,"
4836 			  " but 'external_size' not in effect?\n", __func__);
4837 		printk(KERN_ERR
4838 		       "md: invalid array_size %llu > default size %llu\n",
4839 		       (unsigned long long)mddev->array_sectors / 2,
4840 		       (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
4841 		err = -EINVAL;
4842 		mddev->pers->stop(mddev);
4843 	}
4844 	if (err == 0 && mddev->pers->sync_request) {
4845 		err = bitmap_create(mddev);
4846 		if (err) {
4847 			printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
4848 			       mdname(mddev), err);
4849 			mddev->pers->stop(mddev);
4850 		}
4851 	}
4852 	if (err) {
4853 		module_put(mddev->pers->owner);
4854 		mddev->pers = NULL;
4855 		bitmap_destroy(mddev);
4856 		return err;
4857 	}
4858 	if (mddev->pers->sync_request) {
4859 		if (mddev->kobj.sd &&
4860 		    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
4861 			printk(KERN_WARNING
4862 			       "md: cannot register extra attributes for %s\n",
4863 			       mdname(mddev));
4864 		mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
4865 	} else if (mddev->ro == 2) /* auto-readonly not meaningful */
4866 		mddev->ro = 0;
4867 
4868  	atomic_set(&mddev->writes_pending,0);
4869 	atomic_set(&mddev->max_corr_read_errors,
4870 		   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
4871 	mddev->safemode = 0;
4872 	mddev->safemode_timer.function = md_safemode_timeout;
4873 	mddev->safemode_timer.data = (unsigned long) mddev;
4874 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
4875 	mddev->in_sync = 1;
4876 	smp_wmb();
4877 	mddev->ready = 1;
4878 	list_for_each_entry(rdev, &mddev->disks, same_set)
4879 		if (rdev->raid_disk >= 0)
4880 			if (sysfs_link_rdev(mddev, rdev))
4881 				/* failure here is OK */;
4882 
4883 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4884 
4885 	if (mddev->flags)
4886 		md_update_sb(mddev, 0);
4887 
4888 	md_new_event(mddev);
4889 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4890 	sysfs_notify_dirent_safe(mddev->sysfs_action);
4891 	sysfs_notify(&mddev->kobj, NULL, "degraded");
4892 	return 0;
4893 }
4894 EXPORT_SYMBOL_GPL(md_run);
4895 
4896 static int do_md_run(mddev_t *mddev)
4897 {
4898 	int err;
4899 
4900 	err = md_run(mddev);
4901 	if (err)
4902 		goto out;
4903 	err = bitmap_load(mddev);
4904 	if (err) {
4905 		bitmap_destroy(mddev);
4906 		goto out;
4907 	}
4908 
4909 	md_wakeup_thread(mddev->thread);
4910 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
4911 
4912 	set_capacity(mddev->gendisk, mddev->array_sectors);
4913 	revalidate_disk(mddev->gendisk);
4914 	mddev->changed = 1;
4915 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
4916 out:
4917 	return err;
4918 }
4919 
4920 static int restart_array(mddev_t *mddev)
4921 {
4922 	struct gendisk *disk = mddev->gendisk;
4923 
4924 	/* Complain if it has no devices */
4925 	if (list_empty(&mddev->disks))
4926 		return -ENXIO;
4927 	if (!mddev->pers)
4928 		return -EINVAL;
4929 	if (!mddev->ro)
4930 		return -EBUSY;
4931 	mddev->safemode = 0;
4932 	mddev->ro = 0;
4933 	set_disk_ro(disk, 0);
4934 	printk(KERN_INFO "md: %s switched to read-write mode.\n",
4935 		mdname(mddev));
4936 	/* Kick recovery or resync if necessary */
4937 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4938 	md_wakeup_thread(mddev->thread);
4939 	md_wakeup_thread(mddev->sync_thread);
4940 	sysfs_notify_dirent_safe(mddev->sysfs_state);
4941 	return 0;
4942 }
4943 
4944 /* similar to deny_write_access, but accounts for our holding a reference
4945  * to the file ourselves */
4946 static int deny_bitmap_write_access(struct file * file)
4947 {
4948 	struct inode *inode = file->f_mapping->host;
4949 
4950 	spin_lock(&inode->i_lock);
4951 	if (atomic_read(&inode->i_writecount) > 1) {
4952 		spin_unlock(&inode->i_lock);
4953 		return -ETXTBSY;
4954 	}
4955 	atomic_set(&inode->i_writecount, -1);
4956 	spin_unlock(&inode->i_lock);
4957 
4958 	return 0;
4959 }
4960 
4961 void restore_bitmap_write_access(struct file *file)
4962 {
4963 	struct inode *inode = file->f_mapping->host;
4964 
4965 	spin_lock(&inode->i_lock);
4966 	atomic_set(&inode->i_writecount, 1);
4967 	spin_unlock(&inode->i_lock);
4968 }
4969 
4970 static void md_clean(mddev_t *mddev)
4971 {
4972 	mddev->array_sectors = 0;
4973 	mddev->external_size = 0;
4974 	mddev->dev_sectors = 0;
4975 	mddev->raid_disks = 0;
4976 	mddev->recovery_cp = 0;
4977 	mddev->resync_min = 0;
4978 	mddev->resync_max = MaxSector;
4979 	mddev->reshape_position = MaxSector;
4980 	mddev->external = 0;
4981 	mddev->persistent = 0;
4982 	mddev->level = LEVEL_NONE;
4983 	mddev->clevel[0] = 0;
4984 	mddev->flags = 0;
4985 	mddev->ro = 0;
4986 	mddev->metadata_type[0] = 0;
4987 	mddev->chunk_sectors = 0;
4988 	mddev->ctime = mddev->utime = 0;
4989 	mddev->layout = 0;
4990 	mddev->max_disks = 0;
4991 	mddev->events = 0;
4992 	mddev->can_decrease_events = 0;
4993 	mddev->delta_disks = 0;
4994 	mddev->new_level = LEVEL_NONE;
4995 	mddev->new_layout = 0;
4996 	mddev->new_chunk_sectors = 0;
4997 	mddev->curr_resync = 0;
4998 	mddev->resync_mismatches = 0;
4999 	mddev->suspend_lo = mddev->suspend_hi = 0;
5000 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
5001 	mddev->recovery = 0;
5002 	mddev->in_sync = 0;
5003 	mddev->changed = 0;
5004 	mddev->degraded = 0;
5005 	mddev->safemode = 0;
5006 	mddev->bitmap_info.offset = 0;
5007 	mddev->bitmap_info.default_offset = 0;
5008 	mddev->bitmap_info.chunksize = 0;
5009 	mddev->bitmap_info.daemon_sleep = 0;
5010 	mddev->bitmap_info.max_write_behind = 0;
5011 }
5012 
5013 static void __md_stop_writes(mddev_t *mddev)
5014 {
5015 	if (mddev->sync_thread) {
5016 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5017 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5018 		reap_sync_thread(mddev);
5019 	}
5020 
5021 	del_timer_sync(&mddev->safemode_timer);
5022 
5023 	bitmap_flush(mddev);
5024 	md_super_wait(mddev);
5025 
5026 	if (!mddev->in_sync || mddev->flags) {
5027 		/* mark array as shutdown cleanly */
5028 		mddev->in_sync = 1;
5029 		md_update_sb(mddev, 1);
5030 	}
5031 }
5032 
5033 void md_stop_writes(mddev_t *mddev)
5034 {
5035 	mddev_lock(mddev);
5036 	__md_stop_writes(mddev);
5037 	mddev_unlock(mddev);
5038 }
5039 EXPORT_SYMBOL_GPL(md_stop_writes);
5040 
5041 void md_stop(mddev_t *mddev)
5042 {
5043 	mddev->ready = 0;
5044 	mddev->pers->stop(mddev);
5045 	if (mddev->pers->sync_request && mddev->to_remove == NULL)
5046 		mddev->to_remove = &md_redundancy_group;
5047 	module_put(mddev->pers->owner);
5048 	mddev->pers = NULL;
5049 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5050 }
5051 EXPORT_SYMBOL_GPL(md_stop);
5052 
5053 static int md_set_readonly(mddev_t *mddev, int is_open)
5054 {
5055 	int err = 0;
5056 	mutex_lock(&mddev->open_mutex);
5057 	if (atomic_read(&mddev->openers) > is_open) {
5058 		printk("md: %s still in use.\n",mdname(mddev));
5059 		err = -EBUSY;
5060 		goto out;
5061 	}
5062 	if (mddev->pers) {
5063 		__md_stop_writes(mddev);
5064 
5065 		err  = -ENXIO;
5066 		if (mddev->ro==1)
5067 			goto out;
5068 		mddev->ro = 1;
5069 		set_disk_ro(mddev->gendisk, 1);
5070 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5071 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5072 		err = 0;
5073 	}
5074 out:
5075 	mutex_unlock(&mddev->open_mutex);
5076 	return err;
5077 }
5078 
5079 /* mode:
5080  *   0 - completely stop and dis-assemble array
5081  *   2 - stop but do not disassemble array
5082  */
5083 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
5084 {
5085 	struct gendisk *disk = mddev->gendisk;
5086 	mdk_rdev_t *rdev;
5087 
5088 	mutex_lock(&mddev->open_mutex);
5089 	if (atomic_read(&mddev->openers) > is_open ||
5090 	    mddev->sysfs_active) {
5091 		printk("md: %s still in use.\n",mdname(mddev));
5092 		mutex_unlock(&mddev->open_mutex);
5093 		return -EBUSY;
5094 	}
5095 
5096 	if (mddev->pers) {
5097 		if (mddev->ro)
5098 			set_disk_ro(disk, 0);
5099 
5100 		__md_stop_writes(mddev);
5101 		md_stop(mddev);
5102 		mddev->queue->merge_bvec_fn = NULL;
5103 		mddev->queue->backing_dev_info.congested_fn = NULL;
5104 
5105 		/* tell userspace to handle 'inactive' */
5106 		sysfs_notify_dirent_safe(mddev->sysfs_state);
5107 
5108 		list_for_each_entry(rdev, &mddev->disks, same_set)
5109 			if (rdev->raid_disk >= 0)
5110 				sysfs_unlink_rdev(mddev, rdev);
5111 
5112 		set_capacity(disk, 0);
5113 		mutex_unlock(&mddev->open_mutex);
5114 		mddev->changed = 1;
5115 		revalidate_disk(disk);
5116 
5117 		if (mddev->ro)
5118 			mddev->ro = 0;
5119 	} else
5120 		mutex_unlock(&mddev->open_mutex);
5121 	/*
5122 	 * Free resources if final stop
5123 	 */
5124 	if (mode == 0) {
5125 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5126 
5127 		bitmap_destroy(mddev);
5128 		if (mddev->bitmap_info.file) {
5129 			restore_bitmap_write_access(mddev->bitmap_info.file);
5130 			fput(mddev->bitmap_info.file);
5131 			mddev->bitmap_info.file = NULL;
5132 		}
5133 		mddev->bitmap_info.offset = 0;
5134 
5135 		export_array(mddev);
5136 
5137 		md_clean(mddev);
5138 		kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5139 		if (mddev->hold_active == UNTIL_STOP)
5140 			mddev->hold_active = 0;
5141 	}
5142 	blk_integrity_unregister(disk);
5143 	md_new_event(mddev);
5144 	sysfs_notify_dirent_safe(mddev->sysfs_state);
5145 	return 0;
5146 }
5147 
5148 #ifndef MODULE
5149 static void autorun_array(mddev_t *mddev)
5150 {
5151 	mdk_rdev_t *rdev;
5152 	int err;
5153 
5154 	if (list_empty(&mddev->disks))
5155 		return;
5156 
5157 	printk(KERN_INFO "md: running: ");
5158 
5159 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5160 		char b[BDEVNAME_SIZE];
5161 		printk("<%s>", bdevname(rdev->bdev,b));
5162 	}
5163 	printk("\n");
5164 
5165 	err = do_md_run(mddev);
5166 	if (err) {
5167 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5168 		do_md_stop(mddev, 0, 0);
5169 	}
5170 }
5171 
5172 /*
5173  * lets try to run arrays based on all disks that have arrived
5174  * until now. (those are in pending_raid_disks)
5175  *
5176  * the method: pick the first pending disk, collect all disks with
5177  * the same UUID, remove all from the pending list and put them into
5178  * the 'same_array' list. Then order this list based on superblock
5179  * update time (freshest comes first), kick out 'old' disks and
5180  * compare superblocks. If everything's fine then run it.
5181  *
5182  * If "unit" is allocated, then bump its reference count
5183  */
5184 static void autorun_devices(int part)
5185 {
5186 	mdk_rdev_t *rdev0, *rdev, *tmp;
5187 	mddev_t *mddev;
5188 	char b[BDEVNAME_SIZE];
5189 
5190 	printk(KERN_INFO "md: autorun ...\n");
5191 	while (!list_empty(&pending_raid_disks)) {
5192 		int unit;
5193 		dev_t dev;
5194 		LIST_HEAD(candidates);
5195 		rdev0 = list_entry(pending_raid_disks.next,
5196 					 mdk_rdev_t, same_set);
5197 
5198 		printk(KERN_INFO "md: considering %s ...\n",
5199 			bdevname(rdev0->bdev,b));
5200 		INIT_LIST_HEAD(&candidates);
5201 		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5202 			if (super_90_load(rdev, rdev0, 0) >= 0) {
5203 				printk(KERN_INFO "md:  adding %s ...\n",
5204 					bdevname(rdev->bdev,b));
5205 				list_move(&rdev->same_set, &candidates);
5206 			}
5207 		/*
5208 		 * now we have a set of devices, with all of them having
5209 		 * mostly sane superblocks. It's time to allocate the
5210 		 * mddev.
5211 		 */
5212 		if (part) {
5213 			dev = MKDEV(mdp_major,
5214 				    rdev0->preferred_minor << MdpMinorShift);
5215 			unit = MINOR(dev) >> MdpMinorShift;
5216 		} else {
5217 			dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5218 			unit = MINOR(dev);
5219 		}
5220 		if (rdev0->preferred_minor != unit) {
5221 			printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5222 			       bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5223 			break;
5224 		}
5225 
5226 		md_probe(dev, NULL, NULL);
5227 		mddev = mddev_find(dev);
5228 		if (!mddev || !mddev->gendisk) {
5229 			if (mddev)
5230 				mddev_put(mddev);
5231 			printk(KERN_ERR
5232 				"md: cannot allocate memory for md drive.\n");
5233 			break;
5234 		}
5235 		if (mddev_lock(mddev))
5236 			printk(KERN_WARNING "md: %s locked, cannot run\n",
5237 			       mdname(mddev));
5238 		else if (mddev->raid_disks || mddev->major_version
5239 			 || !list_empty(&mddev->disks)) {
5240 			printk(KERN_WARNING
5241 				"md: %s already running, cannot run %s\n",
5242 				mdname(mddev), bdevname(rdev0->bdev,b));
5243 			mddev_unlock(mddev);
5244 		} else {
5245 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
5246 			mddev->persistent = 1;
5247 			rdev_for_each_list(rdev, tmp, &candidates) {
5248 				list_del_init(&rdev->same_set);
5249 				if (bind_rdev_to_array(rdev, mddev))
5250 					export_rdev(rdev);
5251 			}
5252 			autorun_array(mddev);
5253 			mddev_unlock(mddev);
5254 		}
5255 		/* on success, candidates will be empty, on error
5256 		 * it won't...
5257 		 */
5258 		rdev_for_each_list(rdev, tmp, &candidates) {
5259 			list_del_init(&rdev->same_set);
5260 			export_rdev(rdev);
5261 		}
5262 		mddev_put(mddev);
5263 	}
5264 	printk(KERN_INFO "md: ... autorun DONE.\n");
5265 }
5266 #endif /* !MODULE */
5267 
5268 static int get_version(void __user * arg)
5269 {
5270 	mdu_version_t ver;
5271 
5272 	ver.major = MD_MAJOR_VERSION;
5273 	ver.minor = MD_MINOR_VERSION;
5274 	ver.patchlevel = MD_PATCHLEVEL_VERSION;
5275 
5276 	if (copy_to_user(arg, &ver, sizeof(ver)))
5277 		return -EFAULT;
5278 
5279 	return 0;
5280 }
5281 
5282 static int get_array_info(mddev_t * mddev, void __user * arg)
5283 {
5284 	mdu_array_info_t info;
5285 	int nr,working,insync,failed,spare;
5286 	mdk_rdev_t *rdev;
5287 
5288 	nr=working=insync=failed=spare=0;
5289 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5290 		nr++;
5291 		if (test_bit(Faulty, &rdev->flags))
5292 			failed++;
5293 		else {
5294 			working++;
5295 			if (test_bit(In_sync, &rdev->flags))
5296 				insync++;
5297 			else
5298 				spare++;
5299 		}
5300 	}
5301 
5302 	info.major_version = mddev->major_version;
5303 	info.minor_version = mddev->minor_version;
5304 	info.patch_version = MD_PATCHLEVEL_VERSION;
5305 	info.ctime         = mddev->ctime;
5306 	info.level         = mddev->level;
5307 	info.size          = mddev->dev_sectors / 2;
5308 	if (info.size != mddev->dev_sectors / 2) /* overflow */
5309 		info.size = -1;
5310 	info.nr_disks      = nr;
5311 	info.raid_disks    = mddev->raid_disks;
5312 	info.md_minor      = mddev->md_minor;
5313 	info.not_persistent= !mddev->persistent;
5314 
5315 	info.utime         = mddev->utime;
5316 	info.state         = 0;
5317 	if (mddev->in_sync)
5318 		info.state = (1<<MD_SB_CLEAN);
5319 	if (mddev->bitmap && mddev->bitmap_info.offset)
5320 		info.state = (1<<MD_SB_BITMAP_PRESENT);
5321 	info.active_disks  = insync;
5322 	info.working_disks = working;
5323 	info.failed_disks  = failed;
5324 	info.spare_disks   = spare;
5325 
5326 	info.layout        = mddev->layout;
5327 	info.chunk_size    = mddev->chunk_sectors << 9;
5328 
5329 	if (copy_to_user(arg, &info, sizeof(info)))
5330 		return -EFAULT;
5331 
5332 	return 0;
5333 }
5334 
5335 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
5336 {
5337 	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5338 	char *ptr, *buf = NULL;
5339 	int err = -ENOMEM;
5340 
5341 	if (md_allow_write(mddev))
5342 		file = kmalloc(sizeof(*file), GFP_NOIO);
5343 	else
5344 		file = kmalloc(sizeof(*file), GFP_KERNEL);
5345 
5346 	if (!file)
5347 		goto out;
5348 
5349 	/* bitmap disabled, zero the first byte and copy out */
5350 	if (!mddev->bitmap || !mddev->bitmap->file) {
5351 		file->pathname[0] = '\0';
5352 		goto copy_out;
5353 	}
5354 
5355 	buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
5356 	if (!buf)
5357 		goto out;
5358 
5359 	ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
5360 	if (IS_ERR(ptr))
5361 		goto out;
5362 
5363 	strcpy(file->pathname, ptr);
5364 
5365 copy_out:
5366 	err = 0;
5367 	if (copy_to_user(arg, file, sizeof(*file)))
5368 		err = -EFAULT;
5369 out:
5370 	kfree(buf);
5371 	kfree(file);
5372 	return err;
5373 }
5374 
5375 static int get_disk_info(mddev_t * mddev, void __user * arg)
5376 {
5377 	mdu_disk_info_t info;
5378 	mdk_rdev_t *rdev;
5379 
5380 	if (copy_from_user(&info, arg, sizeof(info)))
5381 		return -EFAULT;
5382 
5383 	rdev = find_rdev_nr(mddev, info.number);
5384 	if (rdev) {
5385 		info.major = MAJOR(rdev->bdev->bd_dev);
5386 		info.minor = MINOR(rdev->bdev->bd_dev);
5387 		info.raid_disk = rdev->raid_disk;
5388 		info.state = 0;
5389 		if (test_bit(Faulty, &rdev->flags))
5390 			info.state |= (1<<MD_DISK_FAULTY);
5391 		else if (test_bit(In_sync, &rdev->flags)) {
5392 			info.state |= (1<<MD_DISK_ACTIVE);
5393 			info.state |= (1<<MD_DISK_SYNC);
5394 		}
5395 		if (test_bit(WriteMostly, &rdev->flags))
5396 			info.state |= (1<<MD_DISK_WRITEMOSTLY);
5397 	} else {
5398 		info.major = info.minor = 0;
5399 		info.raid_disk = -1;
5400 		info.state = (1<<MD_DISK_REMOVED);
5401 	}
5402 
5403 	if (copy_to_user(arg, &info, sizeof(info)))
5404 		return -EFAULT;
5405 
5406 	return 0;
5407 }
5408 
5409 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5410 {
5411 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5412 	mdk_rdev_t *rdev;
5413 	dev_t dev = MKDEV(info->major,info->minor);
5414 
5415 	if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5416 		return -EOVERFLOW;
5417 
5418 	if (!mddev->raid_disks) {
5419 		int err;
5420 		/* expecting a device which has a superblock */
5421 		rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5422 		if (IS_ERR(rdev)) {
5423 			printk(KERN_WARNING
5424 				"md: md_import_device returned %ld\n",
5425 				PTR_ERR(rdev));
5426 			return PTR_ERR(rdev);
5427 		}
5428 		if (!list_empty(&mddev->disks)) {
5429 			mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
5430 							mdk_rdev_t, same_set);
5431 			err = super_types[mddev->major_version]
5432 				.load_super(rdev, rdev0, mddev->minor_version);
5433 			if (err < 0) {
5434 				printk(KERN_WARNING
5435 					"md: %s has different UUID to %s\n",
5436 					bdevname(rdev->bdev,b),
5437 					bdevname(rdev0->bdev,b2));
5438 				export_rdev(rdev);
5439 				return -EINVAL;
5440 			}
5441 		}
5442 		err = bind_rdev_to_array(rdev, mddev);
5443 		if (err)
5444 			export_rdev(rdev);
5445 		return err;
5446 	}
5447 
5448 	/*
5449 	 * add_new_disk can be used once the array is assembled
5450 	 * to add "hot spares".  They must already have a superblock
5451 	 * written
5452 	 */
5453 	if (mddev->pers) {
5454 		int err;
5455 		if (!mddev->pers->hot_add_disk) {
5456 			printk(KERN_WARNING
5457 				"%s: personality does not support diskops!\n",
5458 			       mdname(mddev));
5459 			return -EINVAL;
5460 		}
5461 		if (mddev->persistent)
5462 			rdev = md_import_device(dev, mddev->major_version,
5463 						mddev->minor_version);
5464 		else
5465 			rdev = md_import_device(dev, -1, -1);
5466 		if (IS_ERR(rdev)) {
5467 			printk(KERN_WARNING
5468 				"md: md_import_device returned %ld\n",
5469 				PTR_ERR(rdev));
5470 			return PTR_ERR(rdev);
5471 		}
5472 		/* set saved_raid_disk if appropriate */
5473 		if (!mddev->persistent) {
5474 			if (info->state & (1<<MD_DISK_SYNC)  &&
5475 			    info->raid_disk < mddev->raid_disks) {
5476 				rdev->raid_disk = info->raid_disk;
5477 				set_bit(In_sync, &rdev->flags);
5478 			} else
5479 				rdev->raid_disk = -1;
5480 		} else
5481 			super_types[mddev->major_version].
5482 				validate_super(mddev, rdev);
5483 		if ((info->state & (1<<MD_DISK_SYNC)) &&
5484 		    (!test_bit(In_sync, &rdev->flags) ||
5485 		     rdev->raid_disk != info->raid_disk)) {
5486 			/* This was a hot-add request, but events doesn't
5487 			 * match, so reject it.
5488 			 */
5489 			export_rdev(rdev);
5490 			return -EINVAL;
5491 		}
5492 
5493 		if (test_bit(In_sync, &rdev->flags))
5494 			rdev->saved_raid_disk = rdev->raid_disk;
5495 		else
5496 			rdev->saved_raid_disk = -1;
5497 
5498 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
5499 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5500 			set_bit(WriteMostly, &rdev->flags);
5501 		else
5502 			clear_bit(WriteMostly, &rdev->flags);
5503 
5504 		rdev->raid_disk = -1;
5505 		err = bind_rdev_to_array(rdev, mddev);
5506 		if (!err && !mddev->pers->hot_remove_disk) {
5507 			/* If there is hot_add_disk but no hot_remove_disk
5508 			 * then added disks for geometry changes,
5509 			 * and should be added immediately.
5510 			 */
5511 			super_types[mddev->major_version].
5512 				validate_super(mddev, rdev);
5513 			err = mddev->pers->hot_add_disk(mddev, rdev);
5514 			if (err)
5515 				unbind_rdev_from_array(rdev);
5516 		}
5517 		if (err)
5518 			export_rdev(rdev);
5519 		else
5520 			sysfs_notify_dirent_safe(rdev->sysfs_state);
5521 
5522 		md_update_sb(mddev, 1);
5523 		if (mddev->degraded)
5524 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5525 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5526 		if (!err)
5527 			md_new_event(mddev);
5528 		md_wakeup_thread(mddev->thread);
5529 		return err;
5530 	}
5531 
5532 	/* otherwise, add_new_disk is only allowed
5533 	 * for major_version==0 superblocks
5534 	 */
5535 	if (mddev->major_version != 0) {
5536 		printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
5537 		       mdname(mddev));
5538 		return -EINVAL;
5539 	}
5540 
5541 	if (!(info->state & (1<<MD_DISK_FAULTY))) {
5542 		int err;
5543 		rdev = md_import_device(dev, -1, 0);
5544 		if (IS_ERR(rdev)) {
5545 			printk(KERN_WARNING
5546 				"md: error, md_import_device() returned %ld\n",
5547 				PTR_ERR(rdev));
5548 			return PTR_ERR(rdev);
5549 		}
5550 		rdev->desc_nr = info->number;
5551 		if (info->raid_disk < mddev->raid_disks)
5552 			rdev->raid_disk = info->raid_disk;
5553 		else
5554 			rdev->raid_disk = -1;
5555 
5556 		if (rdev->raid_disk < mddev->raid_disks)
5557 			if (info->state & (1<<MD_DISK_SYNC))
5558 				set_bit(In_sync, &rdev->flags);
5559 
5560 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
5561 			set_bit(WriteMostly, &rdev->flags);
5562 
5563 		if (!mddev->persistent) {
5564 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
5565 			rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5566 		} else
5567 			rdev->sb_start = calc_dev_sboffset(rdev);
5568 		rdev->sectors = rdev->sb_start;
5569 
5570 		err = bind_rdev_to_array(rdev, mddev);
5571 		if (err) {
5572 			export_rdev(rdev);
5573 			return err;
5574 		}
5575 	}
5576 
5577 	return 0;
5578 }
5579 
5580 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
5581 {
5582 	char b[BDEVNAME_SIZE];
5583 	mdk_rdev_t *rdev;
5584 
5585 	rdev = find_rdev(mddev, dev);
5586 	if (!rdev)
5587 		return -ENXIO;
5588 
5589 	if (rdev->raid_disk >= 0)
5590 		goto busy;
5591 
5592 	kick_rdev_from_array(rdev);
5593 	md_update_sb(mddev, 1);
5594 	md_new_event(mddev);
5595 
5596 	return 0;
5597 busy:
5598 	printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
5599 		bdevname(rdev->bdev,b), mdname(mddev));
5600 	return -EBUSY;
5601 }
5602 
5603 static int hot_add_disk(mddev_t * mddev, dev_t dev)
5604 {
5605 	char b[BDEVNAME_SIZE];
5606 	int err;
5607 	mdk_rdev_t *rdev;
5608 
5609 	if (!mddev->pers)
5610 		return -ENODEV;
5611 
5612 	if (mddev->major_version != 0) {
5613 		printk(KERN_WARNING "%s: HOT_ADD may only be used with"
5614 			" version-0 superblocks.\n",
5615 			mdname(mddev));
5616 		return -EINVAL;
5617 	}
5618 	if (!mddev->pers->hot_add_disk) {
5619 		printk(KERN_WARNING
5620 			"%s: personality does not support diskops!\n",
5621 			mdname(mddev));
5622 		return -EINVAL;
5623 	}
5624 
5625 	rdev = md_import_device(dev, -1, 0);
5626 	if (IS_ERR(rdev)) {
5627 		printk(KERN_WARNING
5628 			"md: error, md_import_device() returned %ld\n",
5629 			PTR_ERR(rdev));
5630 		return -EINVAL;
5631 	}
5632 
5633 	if (mddev->persistent)
5634 		rdev->sb_start = calc_dev_sboffset(rdev);
5635 	else
5636 		rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
5637 
5638 	rdev->sectors = rdev->sb_start;
5639 
5640 	if (test_bit(Faulty, &rdev->flags)) {
5641 		printk(KERN_WARNING
5642 			"md: can not hot-add faulty %s disk to %s!\n",
5643 			bdevname(rdev->bdev,b), mdname(mddev));
5644 		err = -EINVAL;
5645 		goto abort_export;
5646 	}
5647 	clear_bit(In_sync, &rdev->flags);
5648 	rdev->desc_nr = -1;
5649 	rdev->saved_raid_disk = -1;
5650 	err = bind_rdev_to_array(rdev, mddev);
5651 	if (err)
5652 		goto abort_export;
5653 
5654 	/*
5655 	 * The rest should better be atomic, we can have disk failures
5656 	 * noticed in interrupt contexts ...
5657 	 */
5658 
5659 	rdev->raid_disk = -1;
5660 
5661 	md_update_sb(mddev, 1);
5662 
5663 	/*
5664 	 * Kick recovery, maybe this spare has to be added to the
5665 	 * array immediately.
5666 	 */
5667 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5668 	md_wakeup_thread(mddev->thread);
5669 	md_new_event(mddev);
5670 	return 0;
5671 
5672 abort_export:
5673 	export_rdev(rdev);
5674 	return err;
5675 }
5676 
5677 static int set_bitmap_file(mddev_t *mddev, int fd)
5678 {
5679 	int err;
5680 
5681 	if (mddev->pers) {
5682 		if (!mddev->pers->quiesce)
5683 			return -EBUSY;
5684 		if (mddev->recovery || mddev->sync_thread)
5685 			return -EBUSY;
5686 		/* we should be able to change the bitmap.. */
5687 	}
5688 
5689 
5690 	if (fd >= 0) {
5691 		if (mddev->bitmap)
5692 			return -EEXIST; /* cannot add when bitmap is present */
5693 		mddev->bitmap_info.file = fget(fd);
5694 
5695 		if (mddev->bitmap_info.file == NULL) {
5696 			printk(KERN_ERR "%s: error: failed to get bitmap file\n",
5697 			       mdname(mddev));
5698 			return -EBADF;
5699 		}
5700 
5701 		err = deny_bitmap_write_access(mddev->bitmap_info.file);
5702 		if (err) {
5703 			printk(KERN_ERR "%s: error: bitmap file is already in use\n",
5704 			       mdname(mddev));
5705 			fput(mddev->bitmap_info.file);
5706 			mddev->bitmap_info.file = NULL;
5707 			return err;
5708 		}
5709 		mddev->bitmap_info.offset = 0; /* file overrides offset */
5710 	} else if (mddev->bitmap == NULL)
5711 		return -ENOENT; /* cannot remove what isn't there */
5712 	err = 0;
5713 	if (mddev->pers) {
5714 		mddev->pers->quiesce(mddev, 1);
5715 		if (fd >= 0) {
5716 			err = bitmap_create(mddev);
5717 			if (!err)
5718 				err = bitmap_load(mddev);
5719 		}
5720 		if (fd < 0 || err) {
5721 			bitmap_destroy(mddev);
5722 			fd = -1; /* make sure to put the file */
5723 		}
5724 		mddev->pers->quiesce(mddev, 0);
5725 	}
5726 	if (fd < 0) {
5727 		if (mddev->bitmap_info.file) {
5728 			restore_bitmap_write_access(mddev->bitmap_info.file);
5729 			fput(mddev->bitmap_info.file);
5730 		}
5731 		mddev->bitmap_info.file = NULL;
5732 	}
5733 
5734 	return err;
5735 }
5736 
5737 /*
5738  * set_array_info is used two different ways
5739  * The original usage is when creating a new array.
5740  * In this usage, raid_disks is > 0 and it together with
5741  *  level, size, not_persistent,layout,chunksize determine the
5742  *  shape of the array.
5743  *  This will always create an array with a type-0.90.0 superblock.
5744  * The newer usage is when assembling an array.
5745  *  In this case raid_disks will be 0, and the major_version field is
5746  *  use to determine which style super-blocks are to be found on the devices.
5747  *  The minor and patch _version numbers are also kept incase the
5748  *  super_block handler wishes to interpret them.
5749  */
5750 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
5751 {
5752 
5753 	if (info->raid_disks == 0) {
5754 		/* just setting version number for superblock loading */
5755 		if (info->major_version < 0 ||
5756 		    info->major_version >= ARRAY_SIZE(super_types) ||
5757 		    super_types[info->major_version].name == NULL) {
5758 			/* maybe try to auto-load a module? */
5759 			printk(KERN_INFO
5760 				"md: superblock version %d not known\n",
5761 				info->major_version);
5762 			return -EINVAL;
5763 		}
5764 		mddev->major_version = info->major_version;
5765 		mddev->minor_version = info->minor_version;
5766 		mddev->patch_version = info->patch_version;
5767 		mddev->persistent = !info->not_persistent;
5768 		/* ensure mddev_put doesn't delete this now that there
5769 		 * is some minimal configuration.
5770 		 */
5771 		mddev->ctime         = get_seconds();
5772 		return 0;
5773 	}
5774 	mddev->major_version = MD_MAJOR_VERSION;
5775 	mddev->minor_version = MD_MINOR_VERSION;
5776 	mddev->patch_version = MD_PATCHLEVEL_VERSION;
5777 	mddev->ctime         = get_seconds();
5778 
5779 	mddev->level         = info->level;
5780 	mddev->clevel[0]     = 0;
5781 	mddev->dev_sectors   = 2 * (sector_t)info->size;
5782 	mddev->raid_disks    = info->raid_disks;
5783 	/* don't set md_minor, it is determined by which /dev/md* was
5784 	 * openned
5785 	 */
5786 	if (info->state & (1<<MD_SB_CLEAN))
5787 		mddev->recovery_cp = MaxSector;
5788 	else
5789 		mddev->recovery_cp = 0;
5790 	mddev->persistent    = ! info->not_persistent;
5791 	mddev->external	     = 0;
5792 
5793 	mddev->layout        = info->layout;
5794 	mddev->chunk_sectors = info->chunk_size >> 9;
5795 
5796 	mddev->max_disks     = MD_SB_DISKS;
5797 
5798 	if (mddev->persistent)
5799 		mddev->flags         = 0;
5800 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
5801 
5802 	mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
5803 	mddev->bitmap_info.offset = 0;
5804 
5805 	mddev->reshape_position = MaxSector;
5806 
5807 	/*
5808 	 * Generate a 128 bit UUID
5809 	 */
5810 	get_random_bytes(mddev->uuid, 16);
5811 
5812 	mddev->new_level = mddev->level;
5813 	mddev->new_chunk_sectors = mddev->chunk_sectors;
5814 	mddev->new_layout = mddev->layout;
5815 	mddev->delta_disks = 0;
5816 
5817 	return 0;
5818 }
5819 
5820 void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
5821 {
5822 	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
5823 
5824 	if (mddev->external_size)
5825 		return;
5826 
5827 	mddev->array_sectors = array_sectors;
5828 }
5829 EXPORT_SYMBOL(md_set_array_sectors);
5830 
5831 static int update_size(mddev_t *mddev, sector_t num_sectors)
5832 {
5833 	mdk_rdev_t *rdev;
5834 	int rv;
5835 	int fit = (num_sectors == 0);
5836 
5837 	if (mddev->pers->resize == NULL)
5838 		return -EINVAL;
5839 	/* The "num_sectors" is the number of sectors of each device that
5840 	 * is used.  This can only make sense for arrays with redundancy.
5841 	 * linear and raid0 always use whatever space is available. We can only
5842 	 * consider changing this number if no resync or reconstruction is
5843 	 * happening, and if the new size is acceptable. It must fit before the
5844 	 * sb_start or, if that is <data_offset, it must fit before the size
5845 	 * of each device.  If num_sectors is zero, we find the largest size
5846 	 * that fits.
5847 	 */
5848 	if (mddev->sync_thread)
5849 		return -EBUSY;
5850 	if (mddev->bitmap)
5851 		/* Sorry, cannot grow a bitmap yet, just remove it,
5852 		 * grow, and re-add.
5853 		 */
5854 		return -EBUSY;
5855 	list_for_each_entry(rdev, &mddev->disks, same_set) {
5856 		sector_t avail = rdev->sectors;
5857 
5858 		if (fit && (num_sectors == 0 || num_sectors > avail))
5859 			num_sectors = avail;
5860 		if (avail < num_sectors)
5861 			return -ENOSPC;
5862 	}
5863 	rv = mddev->pers->resize(mddev, num_sectors);
5864 	if (!rv)
5865 		revalidate_disk(mddev->gendisk);
5866 	return rv;
5867 }
5868 
5869 static int update_raid_disks(mddev_t *mddev, int raid_disks)
5870 {
5871 	int rv;
5872 	/* change the number of raid disks */
5873 	if (mddev->pers->check_reshape == NULL)
5874 		return -EINVAL;
5875 	if (raid_disks <= 0 ||
5876 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
5877 		return -EINVAL;
5878 	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
5879 		return -EBUSY;
5880 	mddev->delta_disks = raid_disks - mddev->raid_disks;
5881 
5882 	rv = mddev->pers->check_reshape(mddev);
5883 	if (rv < 0)
5884 		mddev->delta_disks = 0;
5885 	return rv;
5886 }
5887 
5888 
5889 /*
5890  * update_array_info is used to change the configuration of an
5891  * on-line array.
5892  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
5893  * fields in the info are checked against the array.
5894  * Any differences that cannot be handled will cause an error.
5895  * Normally, only one change can be managed at a time.
5896  */
5897 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
5898 {
5899 	int rv = 0;
5900 	int cnt = 0;
5901 	int state = 0;
5902 
5903 	/* calculate expected state,ignoring low bits */
5904 	if (mddev->bitmap && mddev->bitmap_info.offset)
5905 		state |= (1 << MD_SB_BITMAP_PRESENT);
5906 
5907 	if (mddev->major_version != info->major_version ||
5908 	    mddev->minor_version != info->minor_version ||
5909 /*	    mddev->patch_version != info->patch_version || */
5910 	    mddev->ctime         != info->ctime         ||
5911 	    mddev->level         != info->level         ||
5912 /*	    mddev->layout        != info->layout        || */
5913 	    !mddev->persistent	 != info->not_persistent||
5914 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
5915 	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
5916 	    ((state^info->state) & 0xfffffe00)
5917 		)
5918 		return -EINVAL;
5919 	/* Check there is only one change */
5920 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5921 		cnt++;
5922 	if (mddev->raid_disks != info->raid_disks)
5923 		cnt++;
5924 	if (mddev->layout != info->layout)
5925 		cnt++;
5926 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
5927 		cnt++;
5928 	if (cnt == 0)
5929 		return 0;
5930 	if (cnt > 1)
5931 		return -EINVAL;
5932 
5933 	if (mddev->layout != info->layout) {
5934 		/* Change layout
5935 		 * we don't need to do anything at the md level, the
5936 		 * personality will take care of it all.
5937 		 */
5938 		if (mddev->pers->check_reshape == NULL)
5939 			return -EINVAL;
5940 		else {
5941 			mddev->new_layout = info->layout;
5942 			rv = mddev->pers->check_reshape(mddev);
5943 			if (rv)
5944 				mddev->new_layout = mddev->layout;
5945 			return rv;
5946 		}
5947 	}
5948 	if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
5949 		rv = update_size(mddev, (sector_t)info->size * 2);
5950 
5951 	if (mddev->raid_disks    != info->raid_disks)
5952 		rv = update_raid_disks(mddev, info->raid_disks);
5953 
5954 	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
5955 		if (mddev->pers->quiesce == NULL)
5956 			return -EINVAL;
5957 		if (mddev->recovery || mddev->sync_thread)
5958 			return -EBUSY;
5959 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
5960 			/* add the bitmap */
5961 			if (mddev->bitmap)
5962 				return -EEXIST;
5963 			if (mddev->bitmap_info.default_offset == 0)
5964 				return -EINVAL;
5965 			mddev->bitmap_info.offset =
5966 				mddev->bitmap_info.default_offset;
5967 			mddev->pers->quiesce(mddev, 1);
5968 			rv = bitmap_create(mddev);
5969 			if (!rv)
5970 				rv = bitmap_load(mddev);
5971 			if (rv)
5972 				bitmap_destroy(mddev);
5973 			mddev->pers->quiesce(mddev, 0);
5974 		} else {
5975 			/* remove the bitmap */
5976 			if (!mddev->bitmap)
5977 				return -ENOENT;
5978 			if (mddev->bitmap->file)
5979 				return -EINVAL;
5980 			mddev->pers->quiesce(mddev, 1);
5981 			bitmap_destroy(mddev);
5982 			mddev->pers->quiesce(mddev, 0);
5983 			mddev->bitmap_info.offset = 0;
5984 		}
5985 	}
5986 	md_update_sb(mddev, 1);
5987 	return rv;
5988 }
5989 
5990 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
5991 {
5992 	mdk_rdev_t *rdev;
5993 
5994 	if (mddev->pers == NULL)
5995 		return -ENODEV;
5996 
5997 	rdev = find_rdev(mddev, dev);
5998 	if (!rdev)
5999 		return -ENODEV;
6000 
6001 	md_error(mddev, rdev);
6002 	if (!test_bit(Faulty, &rdev->flags))
6003 		return -EBUSY;
6004 	return 0;
6005 }
6006 
6007 /*
6008  * We have a problem here : there is no easy way to give a CHS
6009  * virtual geometry. We currently pretend that we have a 2 heads
6010  * 4 sectors (with a BIG number of cylinders...). This drives
6011  * dosfs just mad... ;-)
6012  */
6013 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6014 {
6015 	mddev_t *mddev = bdev->bd_disk->private_data;
6016 
6017 	geo->heads = 2;
6018 	geo->sectors = 4;
6019 	geo->cylinders = mddev->array_sectors / 8;
6020 	return 0;
6021 }
6022 
6023 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6024 			unsigned int cmd, unsigned long arg)
6025 {
6026 	int err = 0;
6027 	void __user *argp = (void __user *)arg;
6028 	mddev_t *mddev = NULL;
6029 	int ro;
6030 
6031 	if (!capable(CAP_SYS_ADMIN))
6032 		return -EACCES;
6033 
6034 	/*
6035 	 * Commands dealing with the RAID driver but not any
6036 	 * particular array:
6037 	 */
6038 	switch (cmd)
6039 	{
6040 		case RAID_VERSION:
6041 			err = get_version(argp);
6042 			goto done;
6043 
6044 		case PRINT_RAID_DEBUG:
6045 			err = 0;
6046 			md_print_devices();
6047 			goto done;
6048 
6049 #ifndef MODULE
6050 		case RAID_AUTORUN:
6051 			err = 0;
6052 			autostart_arrays(arg);
6053 			goto done;
6054 #endif
6055 		default:;
6056 	}
6057 
6058 	/*
6059 	 * Commands creating/starting a new array:
6060 	 */
6061 
6062 	mddev = bdev->bd_disk->private_data;
6063 
6064 	if (!mddev) {
6065 		BUG();
6066 		goto abort;
6067 	}
6068 
6069 	err = mddev_lock(mddev);
6070 	if (err) {
6071 		printk(KERN_INFO
6072 			"md: ioctl lock interrupted, reason %d, cmd %d\n",
6073 			err, cmd);
6074 		goto abort;
6075 	}
6076 
6077 	switch (cmd)
6078 	{
6079 		case SET_ARRAY_INFO:
6080 			{
6081 				mdu_array_info_t info;
6082 				if (!arg)
6083 					memset(&info, 0, sizeof(info));
6084 				else if (copy_from_user(&info, argp, sizeof(info))) {
6085 					err = -EFAULT;
6086 					goto abort_unlock;
6087 				}
6088 				if (mddev->pers) {
6089 					err = update_array_info(mddev, &info);
6090 					if (err) {
6091 						printk(KERN_WARNING "md: couldn't update"
6092 						       " array info. %d\n", err);
6093 						goto abort_unlock;
6094 					}
6095 					goto done_unlock;
6096 				}
6097 				if (!list_empty(&mddev->disks)) {
6098 					printk(KERN_WARNING
6099 					       "md: array %s already has disks!\n",
6100 					       mdname(mddev));
6101 					err = -EBUSY;
6102 					goto abort_unlock;
6103 				}
6104 				if (mddev->raid_disks) {
6105 					printk(KERN_WARNING
6106 					       "md: array %s already initialised!\n",
6107 					       mdname(mddev));
6108 					err = -EBUSY;
6109 					goto abort_unlock;
6110 				}
6111 				err = set_array_info(mddev, &info);
6112 				if (err) {
6113 					printk(KERN_WARNING "md: couldn't set"
6114 					       " array info. %d\n", err);
6115 					goto abort_unlock;
6116 				}
6117 			}
6118 			goto done_unlock;
6119 
6120 		default:;
6121 	}
6122 
6123 	/*
6124 	 * Commands querying/configuring an existing array:
6125 	 */
6126 	/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6127 	 * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6128 	if ((!mddev->raid_disks && !mddev->external)
6129 	    && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6130 	    && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6131 	    && cmd != GET_BITMAP_FILE) {
6132 		err = -ENODEV;
6133 		goto abort_unlock;
6134 	}
6135 
6136 	/*
6137 	 * Commands even a read-only array can execute:
6138 	 */
6139 	switch (cmd)
6140 	{
6141 		case GET_ARRAY_INFO:
6142 			err = get_array_info(mddev, argp);
6143 			goto done_unlock;
6144 
6145 		case GET_BITMAP_FILE:
6146 			err = get_bitmap_file(mddev, argp);
6147 			goto done_unlock;
6148 
6149 		case GET_DISK_INFO:
6150 			err = get_disk_info(mddev, argp);
6151 			goto done_unlock;
6152 
6153 		case RESTART_ARRAY_RW:
6154 			err = restart_array(mddev);
6155 			goto done_unlock;
6156 
6157 		case STOP_ARRAY:
6158 			err = do_md_stop(mddev, 0, 1);
6159 			goto done_unlock;
6160 
6161 		case STOP_ARRAY_RO:
6162 			err = md_set_readonly(mddev, 1);
6163 			goto done_unlock;
6164 
6165 		case BLKROSET:
6166 			if (get_user(ro, (int __user *)(arg))) {
6167 				err = -EFAULT;
6168 				goto done_unlock;
6169 			}
6170 			err = -EINVAL;
6171 
6172 			/* if the bdev is going readonly the value of mddev->ro
6173 			 * does not matter, no writes are coming
6174 			 */
6175 			if (ro)
6176 				goto done_unlock;
6177 
6178 			/* are we are already prepared for writes? */
6179 			if (mddev->ro != 1)
6180 				goto done_unlock;
6181 
6182 			/* transitioning to readauto need only happen for
6183 			 * arrays that call md_write_start
6184 			 */
6185 			if (mddev->pers) {
6186 				err = restart_array(mddev);
6187 				if (err == 0) {
6188 					mddev->ro = 2;
6189 					set_disk_ro(mddev->gendisk, 0);
6190 				}
6191 			}
6192 			goto done_unlock;
6193 	}
6194 
6195 	/*
6196 	 * The remaining ioctls are changing the state of the
6197 	 * superblock, so we do not allow them on read-only arrays.
6198 	 * However non-MD ioctls (e.g. get-size) will still come through
6199 	 * here and hit the 'default' below, so only disallow
6200 	 * 'md' ioctls, and switch to rw mode if started auto-readonly.
6201 	 */
6202 	if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
6203 		if (mddev->ro == 2) {
6204 			mddev->ro = 0;
6205 			sysfs_notify_dirent_safe(mddev->sysfs_state);
6206 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6207 			md_wakeup_thread(mddev->thread);
6208 		} else {
6209 			err = -EROFS;
6210 			goto abort_unlock;
6211 		}
6212 	}
6213 
6214 	switch (cmd)
6215 	{
6216 		case ADD_NEW_DISK:
6217 		{
6218 			mdu_disk_info_t info;
6219 			if (copy_from_user(&info, argp, sizeof(info)))
6220 				err = -EFAULT;
6221 			else
6222 				err = add_new_disk(mddev, &info);
6223 			goto done_unlock;
6224 		}
6225 
6226 		case HOT_REMOVE_DISK:
6227 			err = hot_remove_disk(mddev, new_decode_dev(arg));
6228 			goto done_unlock;
6229 
6230 		case HOT_ADD_DISK:
6231 			err = hot_add_disk(mddev, new_decode_dev(arg));
6232 			goto done_unlock;
6233 
6234 		case SET_DISK_FAULTY:
6235 			err = set_disk_faulty(mddev, new_decode_dev(arg));
6236 			goto done_unlock;
6237 
6238 		case RUN_ARRAY:
6239 			err = do_md_run(mddev);
6240 			goto done_unlock;
6241 
6242 		case SET_BITMAP_FILE:
6243 			err = set_bitmap_file(mddev, (int)arg);
6244 			goto done_unlock;
6245 
6246 		default:
6247 			err = -EINVAL;
6248 			goto abort_unlock;
6249 	}
6250 
6251 done_unlock:
6252 abort_unlock:
6253 	if (mddev->hold_active == UNTIL_IOCTL &&
6254 	    err != -EINVAL)
6255 		mddev->hold_active = 0;
6256 	mddev_unlock(mddev);
6257 
6258 	return err;
6259 done:
6260 	if (err)
6261 		MD_BUG();
6262 abort:
6263 	return err;
6264 }
6265 #ifdef CONFIG_COMPAT
6266 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
6267 		    unsigned int cmd, unsigned long arg)
6268 {
6269 	switch (cmd) {
6270 	case HOT_REMOVE_DISK:
6271 	case HOT_ADD_DISK:
6272 	case SET_DISK_FAULTY:
6273 	case SET_BITMAP_FILE:
6274 		/* These take in integer arg, do not convert */
6275 		break;
6276 	default:
6277 		arg = (unsigned long)compat_ptr(arg);
6278 		break;
6279 	}
6280 
6281 	return md_ioctl(bdev, mode, cmd, arg);
6282 }
6283 #endif /* CONFIG_COMPAT */
6284 
6285 static int md_open(struct block_device *bdev, fmode_t mode)
6286 {
6287 	/*
6288 	 * Succeed if we can lock the mddev, which confirms that
6289 	 * it isn't being stopped right now.
6290 	 */
6291 	mddev_t *mddev = mddev_find(bdev->bd_dev);
6292 	int err;
6293 
6294 	if (mddev->gendisk != bdev->bd_disk) {
6295 		/* we are racing with mddev_put which is discarding this
6296 		 * bd_disk.
6297 		 */
6298 		mddev_put(mddev);
6299 		/* Wait until bdev->bd_disk is definitely gone */
6300 		flush_workqueue(md_misc_wq);
6301 		/* Then retry the open from the top */
6302 		return -ERESTARTSYS;
6303 	}
6304 	BUG_ON(mddev != bdev->bd_disk->private_data);
6305 
6306 	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
6307 		goto out;
6308 
6309 	err = 0;
6310 	atomic_inc(&mddev->openers);
6311 	mutex_unlock(&mddev->open_mutex);
6312 
6313 	check_disk_change(bdev);
6314  out:
6315 	return err;
6316 }
6317 
6318 static int md_release(struct gendisk *disk, fmode_t mode)
6319 {
6320  	mddev_t *mddev = disk->private_data;
6321 
6322 	BUG_ON(!mddev);
6323 	atomic_dec(&mddev->openers);
6324 	mddev_put(mddev);
6325 
6326 	return 0;
6327 }
6328 
6329 static int md_media_changed(struct gendisk *disk)
6330 {
6331 	mddev_t *mddev = disk->private_data;
6332 
6333 	return mddev->changed;
6334 }
6335 
6336 static int md_revalidate(struct gendisk *disk)
6337 {
6338 	mddev_t *mddev = disk->private_data;
6339 
6340 	mddev->changed = 0;
6341 	return 0;
6342 }
6343 static const struct block_device_operations md_fops =
6344 {
6345 	.owner		= THIS_MODULE,
6346 	.open		= md_open,
6347 	.release	= md_release,
6348 	.ioctl		= md_ioctl,
6349 #ifdef CONFIG_COMPAT
6350 	.compat_ioctl	= md_compat_ioctl,
6351 #endif
6352 	.getgeo		= md_getgeo,
6353 	.media_changed  = md_media_changed,
6354 	.revalidate_disk= md_revalidate,
6355 };
6356 
6357 static int md_thread(void * arg)
6358 {
6359 	mdk_thread_t *thread = arg;
6360 
6361 	/*
6362 	 * md_thread is a 'system-thread', it's priority should be very
6363 	 * high. We avoid resource deadlocks individually in each
6364 	 * raid personality. (RAID5 does preallocation) We also use RR and
6365 	 * the very same RT priority as kswapd, thus we will never get
6366 	 * into a priority inversion deadlock.
6367 	 *
6368 	 * we definitely have to have equal or higher priority than
6369 	 * bdflush, otherwise bdflush will deadlock if there are too
6370 	 * many dirty RAID5 blocks.
6371 	 */
6372 
6373 	allow_signal(SIGKILL);
6374 	while (!kthread_should_stop()) {
6375 
6376 		/* We need to wait INTERRUPTIBLE so that
6377 		 * we don't add to the load-average.
6378 		 * That means we need to be sure no signals are
6379 		 * pending
6380 		 */
6381 		if (signal_pending(current))
6382 			flush_signals(current);
6383 
6384 		wait_event_interruptible_timeout
6385 			(thread->wqueue,
6386 			 test_bit(THREAD_WAKEUP, &thread->flags)
6387 			 || kthread_should_stop(),
6388 			 thread->timeout);
6389 
6390 		clear_bit(THREAD_WAKEUP, &thread->flags);
6391 		if (!kthread_should_stop())
6392 			thread->run(thread->mddev);
6393 	}
6394 
6395 	return 0;
6396 }
6397 
6398 void md_wakeup_thread(mdk_thread_t *thread)
6399 {
6400 	if (thread) {
6401 		dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
6402 		set_bit(THREAD_WAKEUP, &thread->flags);
6403 		wake_up(&thread->wqueue);
6404 	}
6405 }
6406 
6407 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
6408 				 const char *name)
6409 {
6410 	mdk_thread_t *thread;
6411 
6412 	thread = kzalloc(sizeof(mdk_thread_t), GFP_KERNEL);
6413 	if (!thread)
6414 		return NULL;
6415 
6416 	init_waitqueue_head(&thread->wqueue);
6417 
6418 	thread->run = run;
6419 	thread->mddev = mddev;
6420 	thread->timeout = MAX_SCHEDULE_TIMEOUT;
6421 	thread->tsk = kthread_run(md_thread, thread,
6422 				  "%s_%s",
6423 				  mdname(thread->mddev),
6424 				  name ?: mddev->pers->name);
6425 	if (IS_ERR(thread->tsk)) {
6426 		kfree(thread);
6427 		return NULL;
6428 	}
6429 	return thread;
6430 }
6431 
6432 void md_unregister_thread(mdk_thread_t *thread)
6433 {
6434 	if (!thread)
6435 		return;
6436 	dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
6437 
6438 	kthread_stop(thread->tsk);
6439 	kfree(thread);
6440 }
6441 
6442 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
6443 {
6444 	if (!mddev) {
6445 		MD_BUG();
6446 		return;
6447 	}
6448 
6449 	if (!rdev || test_bit(Faulty, &rdev->flags))
6450 		return;
6451 
6452 	if (!mddev->pers || !mddev->pers->error_handler)
6453 		return;
6454 	mddev->pers->error_handler(mddev,rdev);
6455 	if (mddev->degraded)
6456 		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6457 	sysfs_notify_dirent_safe(rdev->sysfs_state);
6458 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6459 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6460 	md_wakeup_thread(mddev->thread);
6461 	if (mddev->event_work.func)
6462 		queue_work(md_misc_wq, &mddev->event_work);
6463 	md_new_event_inintr(mddev);
6464 }
6465 
6466 /* seq_file implementation /proc/mdstat */
6467 
6468 static void status_unused(struct seq_file *seq)
6469 {
6470 	int i = 0;
6471 	mdk_rdev_t *rdev;
6472 
6473 	seq_printf(seq, "unused devices: ");
6474 
6475 	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
6476 		char b[BDEVNAME_SIZE];
6477 		i++;
6478 		seq_printf(seq, "%s ",
6479 			      bdevname(rdev->bdev,b));
6480 	}
6481 	if (!i)
6482 		seq_printf(seq, "<none>");
6483 
6484 	seq_printf(seq, "\n");
6485 }
6486 
6487 
6488 static void status_resync(struct seq_file *seq, mddev_t * mddev)
6489 {
6490 	sector_t max_sectors, resync, res;
6491 	unsigned long dt, db;
6492 	sector_t rt;
6493 	int scale;
6494 	unsigned int per_milli;
6495 
6496 	resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
6497 
6498 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
6499 		max_sectors = mddev->resync_max_sectors;
6500 	else
6501 		max_sectors = mddev->dev_sectors;
6502 
6503 	/*
6504 	 * Should not happen.
6505 	 */
6506 	if (!max_sectors) {
6507 		MD_BUG();
6508 		return;
6509 	}
6510 	/* Pick 'scale' such that (resync>>scale)*1000 will fit
6511 	 * in a sector_t, and (max_sectors>>scale) will fit in a
6512 	 * u32, as those are the requirements for sector_div.
6513 	 * Thus 'scale' must be at least 10
6514 	 */
6515 	scale = 10;
6516 	if (sizeof(sector_t) > sizeof(unsigned long)) {
6517 		while ( max_sectors/2 > (1ULL<<(scale+32)))
6518 			scale++;
6519 	}
6520 	res = (resync>>scale)*1000;
6521 	sector_div(res, (u32)((max_sectors>>scale)+1));
6522 
6523 	per_milli = res;
6524 	{
6525 		int i, x = per_milli/50, y = 20-x;
6526 		seq_printf(seq, "[");
6527 		for (i = 0; i < x; i++)
6528 			seq_printf(seq, "=");
6529 		seq_printf(seq, ">");
6530 		for (i = 0; i < y; i++)
6531 			seq_printf(seq, ".");
6532 		seq_printf(seq, "] ");
6533 	}
6534 	seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
6535 		   (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
6536 		    "reshape" :
6537 		    (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
6538 		     "check" :
6539 		     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
6540 		      "resync" : "recovery"))),
6541 		   per_milli/10, per_milli % 10,
6542 		   (unsigned long long) resync/2,
6543 		   (unsigned long long) max_sectors/2);
6544 
6545 	/*
6546 	 * dt: time from mark until now
6547 	 * db: blocks written from mark until now
6548 	 * rt: remaining time
6549 	 *
6550 	 * rt is a sector_t, so could be 32bit or 64bit.
6551 	 * So we divide before multiply in case it is 32bit and close
6552 	 * to the limit.
6553 	 * We scale the divisor (db) by 32 to avoid losing precision
6554 	 * near the end of resync when the number of remaining sectors
6555 	 * is close to 'db'.
6556 	 * We then divide rt by 32 after multiplying by db to compensate.
6557 	 * The '+1' avoids division by zero if db is very small.
6558 	 */
6559 	dt = ((jiffies - mddev->resync_mark) / HZ);
6560 	if (!dt) dt++;
6561 	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
6562 		- mddev->resync_mark_cnt;
6563 
6564 	rt = max_sectors - resync;    /* number of remaining sectors */
6565 	sector_div(rt, db/32+1);
6566 	rt *= dt;
6567 	rt >>= 5;
6568 
6569 	seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
6570 		   ((unsigned long)rt % 60)/6);
6571 
6572 	seq_printf(seq, " speed=%ldK/sec", db/2/dt);
6573 }
6574 
6575 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
6576 {
6577 	struct list_head *tmp;
6578 	loff_t l = *pos;
6579 	mddev_t *mddev;
6580 
6581 	if (l >= 0x10000)
6582 		return NULL;
6583 	if (!l--)
6584 		/* header */
6585 		return (void*)1;
6586 
6587 	spin_lock(&all_mddevs_lock);
6588 	list_for_each(tmp,&all_mddevs)
6589 		if (!l--) {
6590 			mddev = list_entry(tmp, mddev_t, all_mddevs);
6591 			mddev_get(mddev);
6592 			spin_unlock(&all_mddevs_lock);
6593 			return mddev;
6594 		}
6595 	spin_unlock(&all_mddevs_lock);
6596 	if (!l--)
6597 		return (void*)2;/* tail */
6598 	return NULL;
6599 }
6600 
6601 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
6602 {
6603 	struct list_head *tmp;
6604 	mddev_t *next_mddev, *mddev = v;
6605 
6606 	++*pos;
6607 	if (v == (void*)2)
6608 		return NULL;
6609 
6610 	spin_lock(&all_mddevs_lock);
6611 	if (v == (void*)1)
6612 		tmp = all_mddevs.next;
6613 	else
6614 		tmp = mddev->all_mddevs.next;
6615 	if (tmp != &all_mddevs)
6616 		next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
6617 	else {
6618 		next_mddev = (void*)2;
6619 		*pos = 0x10000;
6620 	}
6621 	spin_unlock(&all_mddevs_lock);
6622 
6623 	if (v != (void*)1)
6624 		mddev_put(mddev);
6625 	return next_mddev;
6626 
6627 }
6628 
6629 static void md_seq_stop(struct seq_file *seq, void *v)
6630 {
6631 	mddev_t *mddev = v;
6632 
6633 	if (mddev && v != (void*)1 && v != (void*)2)
6634 		mddev_put(mddev);
6635 }
6636 
6637 static int md_seq_show(struct seq_file *seq, void *v)
6638 {
6639 	mddev_t *mddev = v;
6640 	sector_t sectors;
6641 	mdk_rdev_t *rdev;
6642 	struct bitmap *bitmap;
6643 
6644 	if (v == (void*)1) {
6645 		struct mdk_personality *pers;
6646 		seq_printf(seq, "Personalities : ");
6647 		spin_lock(&pers_lock);
6648 		list_for_each_entry(pers, &pers_list, list)
6649 			seq_printf(seq, "[%s] ", pers->name);
6650 
6651 		spin_unlock(&pers_lock);
6652 		seq_printf(seq, "\n");
6653 		seq->poll_event = atomic_read(&md_event_count);
6654 		return 0;
6655 	}
6656 	if (v == (void*)2) {
6657 		status_unused(seq);
6658 		return 0;
6659 	}
6660 
6661 	if (mddev_lock(mddev) < 0)
6662 		return -EINTR;
6663 
6664 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
6665 		seq_printf(seq, "%s : %sactive", mdname(mddev),
6666 						mddev->pers ? "" : "in");
6667 		if (mddev->pers) {
6668 			if (mddev->ro==1)
6669 				seq_printf(seq, " (read-only)");
6670 			if (mddev->ro==2)
6671 				seq_printf(seq, " (auto-read-only)");
6672 			seq_printf(seq, " %s", mddev->pers->name);
6673 		}
6674 
6675 		sectors = 0;
6676 		list_for_each_entry(rdev, &mddev->disks, same_set) {
6677 			char b[BDEVNAME_SIZE];
6678 			seq_printf(seq, " %s[%d]",
6679 				bdevname(rdev->bdev,b), rdev->desc_nr);
6680 			if (test_bit(WriteMostly, &rdev->flags))
6681 				seq_printf(seq, "(W)");
6682 			if (test_bit(Faulty, &rdev->flags)) {
6683 				seq_printf(seq, "(F)");
6684 				continue;
6685 			} else if (rdev->raid_disk < 0)
6686 				seq_printf(seq, "(S)"); /* spare */
6687 			sectors += rdev->sectors;
6688 		}
6689 
6690 		if (!list_empty(&mddev->disks)) {
6691 			if (mddev->pers)
6692 				seq_printf(seq, "\n      %llu blocks",
6693 					   (unsigned long long)
6694 					   mddev->array_sectors / 2);
6695 			else
6696 				seq_printf(seq, "\n      %llu blocks",
6697 					   (unsigned long long)sectors / 2);
6698 		}
6699 		if (mddev->persistent) {
6700 			if (mddev->major_version != 0 ||
6701 			    mddev->minor_version != 90) {
6702 				seq_printf(seq," super %d.%d",
6703 					   mddev->major_version,
6704 					   mddev->minor_version);
6705 			}
6706 		} else if (mddev->external)
6707 			seq_printf(seq, " super external:%s",
6708 				   mddev->metadata_type);
6709 		else
6710 			seq_printf(seq, " super non-persistent");
6711 
6712 		if (mddev->pers) {
6713 			mddev->pers->status(seq, mddev);
6714 	 		seq_printf(seq, "\n      ");
6715 			if (mddev->pers->sync_request) {
6716 				if (mddev->curr_resync > 2) {
6717 					status_resync(seq, mddev);
6718 					seq_printf(seq, "\n      ");
6719 				} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
6720 					seq_printf(seq, "\tresync=DELAYED\n      ");
6721 				else if (mddev->recovery_cp < MaxSector)
6722 					seq_printf(seq, "\tresync=PENDING\n      ");
6723 			}
6724 		} else
6725 			seq_printf(seq, "\n       ");
6726 
6727 		if ((bitmap = mddev->bitmap)) {
6728 			unsigned long chunk_kb;
6729 			unsigned long flags;
6730 			spin_lock_irqsave(&bitmap->lock, flags);
6731 			chunk_kb = mddev->bitmap_info.chunksize >> 10;
6732 			seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
6733 				"%lu%s chunk",
6734 				bitmap->pages - bitmap->missing_pages,
6735 				bitmap->pages,
6736 				(bitmap->pages - bitmap->missing_pages)
6737 					<< (PAGE_SHIFT - 10),
6738 				chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
6739 				chunk_kb ? "KB" : "B");
6740 			if (bitmap->file) {
6741 				seq_printf(seq, ", file: ");
6742 				seq_path(seq, &bitmap->file->f_path, " \t\n");
6743 			}
6744 
6745 			seq_printf(seq, "\n");
6746 			spin_unlock_irqrestore(&bitmap->lock, flags);
6747 		}
6748 
6749 		seq_printf(seq, "\n");
6750 	}
6751 	mddev_unlock(mddev);
6752 
6753 	return 0;
6754 }
6755 
6756 static const struct seq_operations md_seq_ops = {
6757 	.start  = md_seq_start,
6758 	.next   = md_seq_next,
6759 	.stop   = md_seq_stop,
6760 	.show   = md_seq_show,
6761 };
6762 
6763 static int md_seq_open(struct inode *inode, struct file *file)
6764 {
6765 	struct seq_file *seq;
6766 	int error;
6767 
6768 	error = seq_open(file, &md_seq_ops);
6769 	if (error)
6770 		return error;
6771 
6772 	seq = file->private_data;
6773 	seq->poll_event = atomic_read(&md_event_count);
6774 	return error;
6775 }
6776 
6777 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
6778 {
6779 	struct seq_file *seq = filp->private_data;
6780 	int mask;
6781 
6782 	poll_wait(filp, &md_event_waiters, wait);
6783 
6784 	/* always allow read */
6785 	mask = POLLIN | POLLRDNORM;
6786 
6787 	if (seq->poll_event != atomic_read(&md_event_count))
6788 		mask |= POLLERR | POLLPRI;
6789 	return mask;
6790 }
6791 
6792 static const struct file_operations md_seq_fops = {
6793 	.owner		= THIS_MODULE,
6794 	.open           = md_seq_open,
6795 	.read           = seq_read,
6796 	.llseek         = seq_lseek,
6797 	.release	= seq_release_private,
6798 	.poll		= mdstat_poll,
6799 };
6800 
6801 int register_md_personality(struct mdk_personality *p)
6802 {
6803 	spin_lock(&pers_lock);
6804 	list_add_tail(&p->list, &pers_list);
6805 	printk(KERN_INFO "md: %s personality registered for level %d\n", p->name, p->level);
6806 	spin_unlock(&pers_lock);
6807 	return 0;
6808 }
6809 
6810 int unregister_md_personality(struct mdk_personality *p)
6811 {
6812 	printk(KERN_INFO "md: %s personality unregistered\n", p->name);
6813 	spin_lock(&pers_lock);
6814 	list_del_init(&p->list);
6815 	spin_unlock(&pers_lock);
6816 	return 0;
6817 }
6818 
6819 static int is_mddev_idle(mddev_t *mddev, int init)
6820 {
6821 	mdk_rdev_t * rdev;
6822 	int idle;
6823 	int curr_events;
6824 
6825 	idle = 1;
6826 	rcu_read_lock();
6827 	rdev_for_each_rcu(rdev, mddev) {
6828 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
6829 		curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
6830 			      (int)part_stat_read(&disk->part0, sectors[1]) -
6831 			      atomic_read(&disk->sync_io);
6832 		/* sync IO will cause sync_io to increase before the disk_stats
6833 		 * as sync_io is counted when a request starts, and
6834 		 * disk_stats is counted when it completes.
6835 		 * So resync activity will cause curr_events to be smaller than
6836 		 * when there was no such activity.
6837 		 * non-sync IO will cause disk_stat to increase without
6838 		 * increasing sync_io so curr_events will (eventually)
6839 		 * be larger than it was before.  Once it becomes
6840 		 * substantially larger, the test below will cause
6841 		 * the array to appear non-idle, and resync will slow
6842 		 * down.
6843 		 * If there is a lot of outstanding resync activity when
6844 		 * we set last_event to curr_events, then all that activity
6845 		 * completing might cause the array to appear non-idle
6846 		 * and resync will be slowed down even though there might
6847 		 * not have been non-resync activity.  This will only
6848 		 * happen once though.  'last_events' will soon reflect
6849 		 * the state where there is little or no outstanding
6850 		 * resync requests, and further resync activity will
6851 		 * always make curr_events less than last_events.
6852 		 *
6853 		 */
6854 		if (init || curr_events - rdev->last_events > 64) {
6855 			rdev->last_events = curr_events;
6856 			idle = 0;
6857 		}
6858 	}
6859 	rcu_read_unlock();
6860 	return idle;
6861 }
6862 
6863 void md_done_sync(mddev_t *mddev, int blocks, int ok)
6864 {
6865 	/* another "blocks" (512byte) blocks have been synced */
6866 	atomic_sub(blocks, &mddev->recovery_active);
6867 	wake_up(&mddev->recovery_wait);
6868 	if (!ok) {
6869 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
6870 		md_wakeup_thread(mddev->thread);
6871 		// stop recovery, signal do_sync ....
6872 	}
6873 }
6874 
6875 
6876 /* md_write_start(mddev, bi)
6877  * If we need to update some array metadata (e.g. 'active' flag
6878  * in superblock) before writing, schedule a superblock update
6879  * and wait for it to complete.
6880  */
6881 void md_write_start(mddev_t *mddev, struct bio *bi)
6882 {
6883 	int did_change = 0;
6884 	if (bio_data_dir(bi) != WRITE)
6885 		return;
6886 
6887 	BUG_ON(mddev->ro == 1);
6888 	if (mddev->ro == 2) {
6889 		/* need to switch to read/write */
6890 		mddev->ro = 0;
6891 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6892 		md_wakeup_thread(mddev->thread);
6893 		md_wakeup_thread(mddev->sync_thread);
6894 		did_change = 1;
6895 	}
6896 	atomic_inc(&mddev->writes_pending);
6897 	if (mddev->safemode == 1)
6898 		mddev->safemode = 0;
6899 	if (mddev->in_sync) {
6900 		spin_lock_irq(&mddev->write_lock);
6901 		if (mddev->in_sync) {
6902 			mddev->in_sync = 0;
6903 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6904 			set_bit(MD_CHANGE_PENDING, &mddev->flags);
6905 			md_wakeup_thread(mddev->thread);
6906 			did_change = 1;
6907 		}
6908 		spin_unlock_irq(&mddev->write_lock);
6909 	}
6910 	if (did_change)
6911 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6912 	wait_event(mddev->sb_wait,
6913 		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6914 }
6915 
6916 void md_write_end(mddev_t *mddev)
6917 {
6918 	if (atomic_dec_and_test(&mddev->writes_pending)) {
6919 		if (mddev->safemode == 2)
6920 			md_wakeup_thread(mddev->thread);
6921 		else if (mddev->safemode_delay)
6922 			mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
6923 	}
6924 }
6925 
6926 /* md_allow_write(mddev)
6927  * Calling this ensures that the array is marked 'active' so that writes
6928  * may proceed without blocking.  It is important to call this before
6929  * attempting a GFP_KERNEL allocation while holding the mddev lock.
6930  * Must be called with mddev_lock held.
6931  *
6932  * In the ->external case MD_CHANGE_CLEAN can not be cleared until mddev->lock
6933  * is dropped, so return -EAGAIN after notifying userspace.
6934  */
6935 int md_allow_write(mddev_t *mddev)
6936 {
6937 	if (!mddev->pers)
6938 		return 0;
6939 	if (mddev->ro)
6940 		return 0;
6941 	if (!mddev->pers->sync_request)
6942 		return 0;
6943 
6944 	spin_lock_irq(&mddev->write_lock);
6945 	if (mddev->in_sync) {
6946 		mddev->in_sync = 0;
6947 		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
6948 		set_bit(MD_CHANGE_PENDING, &mddev->flags);
6949 		if (mddev->safemode_delay &&
6950 		    mddev->safemode == 0)
6951 			mddev->safemode = 1;
6952 		spin_unlock_irq(&mddev->write_lock);
6953 		md_update_sb(mddev, 0);
6954 		sysfs_notify_dirent_safe(mddev->sysfs_state);
6955 	} else
6956 		spin_unlock_irq(&mddev->write_lock);
6957 
6958 	if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
6959 		return -EAGAIN;
6960 	else
6961 		return 0;
6962 }
6963 EXPORT_SYMBOL_GPL(md_allow_write);
6964 
6965 #define SYNC_MARKS	10
6966 #define	SYNC_MARK_STEP	(3*HZ)
6967 void md_do_sync(mddev_t *mddev)
6968 {
6969 	mddev_t *mddev2;
6970 	unsigned int currspeed = 0,
6971 		 window;
6972 	sector_t max_sectors,j, io_sectors;
6973 	unsigned long mark[SYNC_MARKS];
6974 	sector_t mark_cnt[SYNC_MARKS];
6975 	int last_mark,m;
6976 	struct list_head *tmp;
6977 	sector_t last_check;
6978 	int skipped = 0;
6979 	mdk_rdev_t *rdev;
6980 	char *desc;
6981 
6982 	/* just incase thread restarts... */
6983 	if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
6984 		return;
6985 	if (mddev->ro) /* never try to sync a read-only array */
6986 		return;
6987 
6988 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
6989 		if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
6990 			desc = "data-check";
6991 		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
6992 			desc = "requested-resync";
6993 		else
6994 			desc = "resync";
6995 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
6996 		desc = "reshape";
6997 	else
6998 		desc = "recovery";
6999 
7000 	/* we overload curr_resync somewhat here.
7001 	 * 0 == not engaged in resync at all
7002 	 * 2 == checking that there is no conflict with another sync
7003 	 * 1 == like 2, but have yielded to allow conflicting resync to
7004 	 *		commense
7005 	 * other == active in resync - this many blocks
7006 	 *
7007 	 * Before starting a resync we must have set curr_resync to
7008 	 * 2, and then checked that every "conflicting" array has curr_resync
7009 	 * less than ours.  When we find one that is the same or higher
7010 	 * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
7011 	 * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
7012 	 * This will mean we have to start checking from the beginning again.
7013 	 *
7014 	 */
7015 
7016 	do {
7017 		mddev->curr_resync = 2;
7018 
7019 	try_again:
7020 		if (kthread_should_stop())
7021 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7022 
7023 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7024 			goto skip;
7025 		for_each_mddev(mddev2, tmp) {
7026 			if (mddev2 == mddev)
7027 				continue;
7028 			if (!mddev->parallel_resync
7029 			&&  mddev2->curr_resync
7030 			&&  match_mddev_units(mddev, mddev2)) {
7031 				DEFINE_WAIT(wq);
7032 				if (mddev < mddev2 && mddev->curr_resync == 2) {
7033 					/* arbitrarily yield */
7034 					mddev->curr_resync = 1;
7035 					wake_up(&resync_wait);
7036 				}
7037 				if (mddev > mddev2 && mddev->curr_resync == 1)
7038 					/* no need to wait here, we can wait the next
7039 					 * time 'round when curr_resync == 2
7040 					 */
7041 					continue;
7042 				/* We need to wait 'interruptible' so as not to
7043 				 * contribute to the load average, and not to
7044 				 * be caught by 'softlockup'
7045 				 */
7046 				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
7047 				if (!kthread_should_stop() &&
7048 				    mddev2->curr_resync >= mddev->curr_resync) {
7049 					printk(KERN_INFO "md: delaying %s of %s"
7050 					       " until %s has finished (they"
7051 					       " share one or more physical units)\n",
7052 					       desc, mdname(mddev), mdname(mddev2));
7053 					mddev_put(mddev2);
7054 					if (signal_pending(current))
7055 						flush_signals(current);
7056 					schedule();
7057 					finish_wait(&resync_wait, &wq);
7058 					goto try_again;
7059 				}
7060 				finish_wait(&resync_wait, &wq);
7061 			}
7062 		}
7063 	} while (mddev->curr_resync < 2);
7064 
7065 	j = 0;
7066 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7067 		/* resync follows the size requested by the personality,
7068 		 * which defaults to physical size, but can be virtual size
7069 		 */
7070 		max_sectors = mddev->resync_max_sectors;
7071 		mddev->resync_mismatches = 0;
7072 		/* we don't use the checkpoint if there's a bitmap */
7073 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7074 			j = mddev->resync_min;
7075 		else if (!mddev->bitmap)
7076 			j = mddev->recovery_cp;
7077 
7078 	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7079 		max_sectors = mddev->dev_sectors;
7080 	else {
7081 		/* recovery follows the physical size of devices */
7082 		max_sectors = mddev->dev_sectors;
7083 		j = MaxSector;
7084 		rcu_read_lock();
7085 		list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
7086 			if (rdev->raid_disk >= 0 &&
7087 			    !test_bit(Faulty, &rdev->flags) &&
7088 			    !test_bit(In_sync, &rdev->flags) &&
7089 			    rdev->recovery_offset < j)
7090 				j = rdev->recovery_offset;
7091 		rcu_read_unlock();
7092 	}
7093 
7094 	printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
7095 	printk(KERN_INFO "md: minimum _guaranteed_  speed:"
7096 		" %d KB/sec/disk.\n", speed_min(mddev));
7097 	printk(KERN_INFO "md: using maximum available idle IO bandwidth "
7098 	       "(but not more than %d KB/sec) for %s.\n",
7099 	       speed_max(mddev), desc);
7100 
7101 	is_mddev_idle(mddev, 1); /* this initializes IO event counters */
7102 
7103 	io_sectors = 0;
7104 	for (m = 0; m < SYNC_MARKS; m++) {
7105 		mark[m] = jiffies;
7106 		mark_cnt[m] = io_sectors;
7107 	}
7108 	last_mark = 0;
7109 	mddev->resync_mark = mark[last_mark];
7110 	mddev->resync_mark_cnt = mark_cnt[last_mark];
7111 
7112 	/*
7113 	 * Tune reconstruction:
7114 	 */
7115 	window = 32*(PAGE_SIZE/512);
7116 	printk(KERN_INFO "md: using %dk window, over a total of %lluk.\n",
7117 		window/2, (unsigned long long)max_sectors/2);
7118 
7119 	atomic_set(&mddev->recovery_active, 0);
7120 	last_check = 0;
7121 
7122 	if (j>2) {
7123 		printk(KERN_INFO
7124 		       "md: resuming %s of %s from checkpoint.\n",
7125 		       desc, mdname(mddev));
7126 		mddev->curr_resync = j;
7127 	}
7128 	mddev->curr_resync_completed = j;
7129 
7130 	while (j < max_sectors) {
7131 		sector_t sectors;
7132 
7133 		skipped = 0;
7134 
7135 		if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7136 		    ((mddev->curr_resync > mddev->curr_resync_completed &&
7137 		      (mddev->curr_resync - mddev->curr_resync_completed)
7138 		      > (max_sectors >> 4)) ||
7139 		     (j - mddev->curr_resync_completed)*2
7140 		     >= mddev->resync_max - mddev->curr_resync_completed
7141 			    )) {
7142 			/* time to update curr_resync_completed */
7143 			wait_event(mddev->recovery_wait,
7144 				   atomic_read(&mddev->recovery_active) == 0);
7145 			mddev->curr_resync_completed = j;
7146 			set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7147 			sysfs_notify(&mddev->kobj, NULL, "sync_completed");
7148 		}
7149 
7150 		while (j >= mddev->resync_max && !kthread_should_stop()) {
7151 			/* As this condition is controlled by user-space,
7152 			 * we can block indefinitely, so use '_interruptible'
7153 			 * to avoid triggering warnings.
7154 			 */
7155 			flush_signals(current); /* just in case */
7156 			wait_event_interruptible(mddev->recovery_wait,
7157 						 mddev->resync_max > j
7158 						 || kthread_should_stop());
7159 		}
7160 
7161 		if (kthread_should_stop())
7162 			goto interrupted;
7163 
7164 		sectors = mddev->pers->sync_request(mddev, j, &skipped,
7165 						  currspeed < speed_min(mddev));
7166 		if (sectors == 0) {
7167 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7168 			goto out;
7169 		}
7170 
7171 		if (!skipped) { /* actual IO requested */
7172 			io_sectors += sectors;
7173 			atomic_add(sectors, &mddev->recovery_active);
7174 		}
7175 
7176 		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7177 			break;
7178 
7179 		j += sectors;
7180 		if (j>1) mddev->curr_resync = j;
7181 		mddev->curr_mark_cnt = io_sectors;
7182 		if (last_check == 0)
7183 			/* this is the earliest that rebuild will be
7184 			 * visible in /proc/mdstat
7185 			 */
7186 			md_new_event(mddev);
7187 
7188 		if (last_check + window > io_sectors || j == max_sectors)
7189 			continue;
7190 
7191 		last_check = io_sectors;
7192 	repeat:
7193 		if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
7194 			/* step marks */
7195 			int next = (last_mark+1) % SYNC_MARKS;
7196 
7197 			mddev->resync_mark = mark[next];
7198 			mddev->resync_mark_cnt = mark_cnt[next];
7199 			mark[next] = jiffies;
7200 			mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
7201 			last_mark = next;
7202 		}
7203 
7204 
7205 		if (kthread_should_stop())
7206 			goto interrupted;
7207 
7208 
7209 		/*
7210 		 * this loop exits only if either when we are slower than
7211 		 * the 'hard' speed limit, or the system was IO-idle for
7212 		 * a jiffy.
7213 		 * the system might be non-idle CPU-wise, but we only care
7214 		 * about not overloading the IO subsystem. (things like an
7215 		 * e2fsck being done on the RAID array should execute fast)
7216 		 */
7217 		cond_resched();
7218 
7219 		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
7220 			/((jiffies-mddev->resync_mark)/HZ +1) +1;
7221 
7222 		if (currspeed > speed_min(mddev)) {
7223 			if ((currspeed > speed_max(mddev)) ||
7224 					!is_mddev_idle(mddev, 0)) {
7225 				msleep(500);
7226 				goto repeat;
7227 			}
7228 		}
7229 	}
7230 	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);
7231 	/*
7232 	 * this also signals 'finished resyncing' to md_stop
7233 	 */
7234  out:
7235 	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
7236 
7237 	/* tell personality that we are finished */
7238 	mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
7239 
7240 	if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
7241 	    mddev->curr_resync > 2) {
7242 		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
7243 			if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7244 				if (mddev->curr_resync >= mddev->recovery_cp) {
7245 					printk(KERN_INFO
7246 					       "md: checkpointing %s of %s.\n",
7247 					       desc, mdname(mddev));
7248 					mddev->recovery_cp = mddev->curr_resync;
7249 				}
7250 			} else
7251 				mddev->recovery_cp = MaxSector;
7252 		} else {
7253 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
7254 				mddev->curr_resync = MaxSector;
7255 			rcu_read_lock();
7256 			list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
7257 				if (rdev->raid_disk >= 0 &&
7258 				    mddev->delta_disks >= 0 &&
7259 				    !test_bit(Faulty, &rdev->flags) &&
7260 				    !test_bit(In_sync, &rdev->flags) &&
7261 				    rdev->recovery_offset < mddev->curr_resync)
7262 					rdev->recovery_offset = mddev->curr_resync;
7263 			rcu_read_unlock();
7264 		}
7265 	}
7266 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
7267 
7268  skip:
7269 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7270 		/* We completed so min/max setting can be forgotten if used. */
7271 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7272 			mddev->resync_min = 0;
7273 		mddev->resync_max = MaxSector;
7274 	} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
7275 		mddev->resync_min = mddev->curr_resync_completed;
7276 	mddev->curr_resync = 0;
7277 	wake_up(&resync_wait);
7278 	set_bit(MD_RECOVERY_DONE, &mddev->recovery);
7279 	md_wakeup_thread(mddev->thread);
7280 	return;
7281 
7282  interrupted:
7283 	/*
7284 	 * got a signal, exit.
7285 	 */
7286 	printk(KERN_INFO
7287 	       "md: md_do_sync() got signal ... exiting\n");
7288 	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7289 	goto out;
7290 
7291 }
7292 EXPORT_SYMBOL_GPL(md_do_sync);
7293 
7294 static int remove_and_add_spares(mddev_t *mddev)
7295 {
7296 	mdk_rdev_t *rdev;
7297 	int spares = 0;
7298 
7299 	mddev->curr_resync_completed = 0;
7300 
7301 	list_for_each_entry(rdev, &mddev->disks, same_set)
7302 		if (rdev->raid_disk >= 0 &&
7303 		    !test_bit(Blocked, &rdev->flags) &&
7304 		    (test_bit(Faulty, &rdev->flags) ||
7305 		     ! test_bit(In_sync, &rdev->flags)) &&
7306 		    atomic_read(&rdev->nr_pending)==0) {
7307 			if (mddev->pers->hot_remove_disk(
7308 				    mddev, rdev->raid_disk)==0) {
7309 				sysfs_unlink_rdev(mddev, rdev);
7310 				rdev->raid_disk = -1;
7311 			}
7312 		}
7313 
7314 	if (mddev->degraded) {
7315 		list_for_each_entry(rdev, &mddev->disks, same_set) {
7316 			if (rdev->raid_disk >= 0 &&
7317 			    !test_bit(In_sync, &rdev->flags) &&
7318 			    !test_bit(Faulty, &rdev->flags))
7319 				spares++;
7320 			if (rdev->raid_disk < 0
7321 			    && !test_bit(Faulty, &rdev->flags)) {
7322 				rdev->recovery_offset = 0;
7323 				if (mddev->pers->
7324 				    hot_add_disk(mddev, rdev) == 0) {
7325 					if (sysfs_link_rdev(mddev, rdev))
7326 						/* failure here is OK */;
7327 					spares++;
7328 					md_new_event(mddev);
7329 					set_bit(MD_CHANGE_DEVS, &mddev->flags);
7330 				} else
7331 					break;
7332 			}
7333 		}
7334 	}
7335 	return spares;
7336 }
7337 
7338 static void reap_sync_thread(mddev_t *mddev)
7339 {
7340 	mdk_rdev_t *rdev;
7341 
7342 	/* resync has finished, collect result */
7343 	md_unregister_thread(mddev->sync_thread);
7344 	mddev->sync_thread = NULL;
7345 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
7346 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
7347 		/* success...*/
7348 		/* activate any spares */
7349 		if (mddev->pers->spare_active(mddev))
7350 			sysfs_notify(&mddev->kobj, NULL,
7351 				     "degraded");
7352 	}
7353 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7354 	    mddev->pers->finish_reshape)
7355 		mddev->pers->finish_reshape(mddev);
7356 	md_update_sb(mddev, 1);
7357 
7358 	/* if array is no-longer degraded, then any saved_raid_disk
7359 	 * information must be scrapped
7360 	 */
7361 	if (!mddev->degraded)
7362 		list_for_each_entry(rdev, &mddev->disks, same_set)
7363 			rdev->saved_raid_disk = -1;
7364 
7365 	clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7366 	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7367 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7368 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7369 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7370 	/* flag recovery needed just to double check */
7371 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7372 	sysfs_notify_dirent_safe(mddev->sysfs_action);
7373 	md_new_event(mddev);
7374 	if (mddev->event_work.func)
7375 		queue_work(md_misc_wq, &mddev->event_work);
7376 }
7377 
7378 /*
7379  * This routine is regularly called by all per-raid-array threads to
7380  * deal with generic issues like resync and super-block update.
7381  * Raid personalities that don't have a thread (linear/raid0) do not
7382  * need this as they never do any recovery or update the superblock.
7383  *
7384  * It does not do any resync itself, but rather "forks" off other threads
7385  * to do that as needed.
7386  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
7387  * "->recovery" and create a thread at ->sync_thread.
7388  * When the thread finishes it sets MD_RECOVERY_DONE
7389  * and wakeups up this thread which will reap the thread and finish up.
7390  * This thread also removes any faulty devices (with nr_pending == 0).
7391  *
7392  * The overall approach is:
7393  *  1/ if the superblock needs updating, update it.
7394  *  2/ If a recovery thread is running, don't do anything else.
7395  *  3/ If recovery has finished, clean up, possibly marking spares active.
7396  *  4/ If there are any faulty devices, remove them.
7397  *  5/ If array is degraded, try to add spares devices
7398  *  6/ If array has spares or is not in-sync, start a resync thread.
7399  */
7400 void md_check_recovery(mddev_t *mddev)
7401 {
7402 	if (mddev->suspended)
7403 		return;
7404 
7405 	if (mddev->bitmap)
7406 		bitmap_daemon_work(mddev);
7407 
7408 	if (signal_pending(current)) {
7409 		if (mddev->pers->sync_request && !mddev->external) {
7410 			printk(KERN_INFO "md: %s in immediate safe mode\n",
7411 			       mdname(mddev));
7412 			mddev->safemode = 2;
7413 		}
7414 		flush_signals(current);
7415 	}
7416 
7417 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
7418 		return;
7419 	if ( ! (
7420 		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
7421 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
7422 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
7423 		(mddev->external == 0 && mddev->safemode == 1) ||
7424 		(mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
7425 		 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
7426 		))
7427 		return;
7428 
7429 	if (mddev_trylock(mddev)) {
7430 		int spares = 0;
7431 
7432 		if (mddev->ro) {
7433 			/* Only thing we do on a ro array is remove
7434 			 * failed devices.
7435 			 */
7436 			mdk_rdev_t *rdev;
7437 			list_for_each_entry(rdev, &mddev->disks, same_set)
7438 				if (rdev->raid_disk >= 0 &&
7439 				    !test_bit(Blocked, &rdev->flags) &&
7440 				    test_bit(Faulty, &rdev->flags) &&
7441 				    atomic_read(&rdev->nr_pending)==0) {
7442 					if (mddev->pers->hot_remove_disk(
7443 						    mddev, rdev->raid_disk)==0) {
7444 						sysfs_unlink_rdev(mddev, rdev);
7445 						rdev->raid_disk = -1;
7446 					}
7447 				}
7448 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7449 			goto unlock;
7450 		}
7451 
7452 		if (!mddev->external) {
7453 			int did_change = 0;
7454 			spin_lock_irq(&mddev->write_lock);
7455 			if (mddev->safemode &&
7456 			    !atomic_read(&mddev->writes_pending) &&
7457 			    !mddev->in_sync &&
7458 			    mddev->recovery_cp == MaxSector) {
7459 				mddev->in_sync = 1;
7460 				did_change = 1;
7461 				set_bit(MD_CHANGE_CLEAN, &mddev->flags);
7462 			}
7463 			if (mddev->safemode == 1)
7464 				mddev->safemode = 0;
7465 			spin_unlock_irq(&mddev->write_lock);
7466 			if (did_change)
7467 				sysfs_notify_dirent_safe(mddev->sysfs_state);
7468 		}
7469 
7470 		if (mddev->flags)
7471 			md_update_sb(mddev, 0);
7472 
7473 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
7474 		    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
7475 			/* resync/recovery still happening */
7476 			clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7477 			goto unlock;
7478 		}
7479 		if (mddev->sync_thread) {
7480 			reap_sync_thread(mddev);
7481 			goto unlock;
7482 		}
7483 		/* Set RUNNING before clearing NEEDED to avoid
7484 		 * any transients in the value of "sync_action".
7485 		 */
7486 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7487 		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7488 		/* Clear some bits that don't mean anything, but
7489 		 * might be left set
7490 		 */
7491 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
7492 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7493 
7494 		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
7495 			goto unlock;
7496 		/* no recovery is running.
7497 		 * remove any failed drives, then
7498 		 * add spares if possible.
7499 		 * Spare are also removed and re-added, to allow
7500 		 * the personality to fail the re-add.
7501 		 */
7502 
7503 		if (mddev->reshape_position != MaxSector) {
7504 			if (mddev->pers->check_reshape == NULL ||
7505 			    mddev->pers->check_reshape(mddev) != 0)
7506 				/* Cannot proceed */
7507 				goto unlock;
7508 			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7509 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7510 		} else if ((spares = remove_and_add_spares(mddev))) {
7511 			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7512 			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7513 			clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7514 			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7515 		} else if (mddev->recovery_cp < MaxSector) {
7516 			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7517 			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7518 		} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
7519 			/* nothing to be done ... */
7520 			goto unlock;
7521 
7522 		if (mddev->pers->sync_request) {
7523 			if (spares && mddev->bitmap && ! mddev->bitmap->file) {
7524 				/* We are adding a device or devices to an array
7525 				 * which has the bitmap stored on all devices.
7526 				 * So make sure all bitmap pages get written
7527 				 */
7528 				bitmap_write_all(mddev->bitmap);
7529 			}
7530 			mddev->sync_thread = md_register_thread(md_do_sync,
7531 								mddev,
7532 								"resync");
7533 			if (!mddev->sync_thread) {
7534 				printk(KERN_ERR "%s: could not start resync"
7535 					" thread...\n",
7536 					mdname(mddev));
7537 				/* leave the spares where they are, it shouldn't hurt */
7538 				clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7539 				clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7540 				clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7541 				clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
7542 				clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7543 			} else
7544 				md_wakeup_thread(mddev->sync_thread);
7545 			sysfs_notify_dirent_safe(mddev->sysfs_action);
7546 			md_new_event(mddev);
7547 		}
7548 	unlock:
7549 		if (!mddev->sync_thread) {
7550 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7551 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
7552 					       &mddev->recovery))
7553 				if (mddev->sysfs_action)
7554 					sysfs_notify_dirent_safe(mddev->sysfs_action);
7555 		}
7556 		mddev_unlock(mddev);
7557 	}
7558 }
7559 
7560 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
7561 {
7562 	sysfs_notify_dirent_safe(rdev->sysfs_state);
7563 	wait_event_timeout(rdev->blocked_wait,
7564 			   !test_bit(Blocked, &rdev->flags) &&
7565 			   !test_bit(BlockedBadBlocks, &rdev->flags),
7566 			   msecs_to_jiffies(5000));
7567 	rdev_dec_pending(rdev, mddev);
7568 }
7569 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
7570 
7571 
7572 /* Bad block management.
7573  * We can record which blocks on each device are 'bad' and so just
7574  * fail those blocks, or that stripe, rather than the whole device.
7575  * Entries in the bad-block table are 64bits wide.  This comprises:
7576  * Length of bad-range, in sectors: 0-511 for lengths 1-512
7577  * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
7578  *  A 'shift' can be set so that larger blocks are tracked and
7579  *  consequently larger devices can be covered.
7580  * 'Acknowledged' flag - 1 bit. - the most significant bit.
7581  *
7582  * Locking of the bad-block table uses a seqlock so md_is_badblock
7583  * might need to retry if it is very unlucky.
7584  * We will sometimes want to check for bad blocks in a bi_end_io function,
7585  * so we use the write_seqlock_irq variant.
7586  *
7587  * When looking for a bad block we specify a range and want to
7588  * know if any block in the range is bad.  So we binary-search
7589  * to the last range that starts at-or-before the given endpoint,
7590  * (or "before the sector after the target range")
7591  * then see if it ends after the given start.
7592  * We return
7593  *  0 if there are no known bad blocks in the range
7594  *  1 if there are known bad block which are all acknowledged
7595  * -1 if there are bad blocks which have not yet been acknowledged in metadata.
7596  * plus the start/length of the first bad section we overlap.
7597  */
7598 int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
7599 		   sector_t *first_bad, int *bad_sectors)
7600 {
7601 	int hi;
7602 	int lo = 0;
7603 	u64 *p = bb->page;
7604 	int rv = 0;
7605 	sector_t target = s + sectors;
7606 	unsigned seq;
7607 
7608 	if (bb->shift > 0) {
7609 		/* round the start down, and the end up */
7610 		s >>= bb->shift;
7611 		target += (1<<bb->shift) - 1;
7612 		target >>= bb->shift;
7613 		sectors = target - s;
7614 	}
7615 	/* 'target' is now the first block after the bad range */
7616 
7617 retry:
7618 	seq = read_seqbegin(&bb->lock);
7619 
7620 	hi = bb->count;
7621 
7622 	/* Binary search between lo and hi for 'target'
7623 	 * i.e. for the last range that starts before 'target'
7624 	 */
7625 	/* INVARIANT: ranges before 'lo' and at-or-after 'hi'
7626 	 * are known not to be the last range before target.
7627 	 * VARIANT: hi-lo is the number of possible
7628 	 * ranges, and decreases until it reaches 1
7629 	 */
7630 	while (hi - lo > 1) {
7631 		int mid = (lo + hi) / 2;
7632 		sector_t a = BB_OFFSET(p[mid]);
7633 		if (a < target)
7634 			/* This could still be the one, earlier ranges
7635 			 * could not. */
7636 			lo = mid;
7637 		else
7638 			/* This and later ranges are definitely out. */
7639 			hi = mid;
7640 	}
7641 	/* 'lo' might be the last that started before target, but 'hi' isn't */
7642 	if (hi > lo) {
7643 		/* need to check all range that end after 's' to see if
7644 		 * any are unacknowledged.
7645 		 */
7646 		while (lo >= 0 &&
7647 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7648 			if (BB_OFFSET(p[lo]) < target) {
7649 				/* starts before the end, and finishes after
7650 				 * the start, so they must overlap
7651 				 */
7652 				if (rv != -1 && BB_ACK(p[lo]))
7653 					rv = 1;
7654 				else
7655 					rv = -1;
7656 				*first_bad = BB_OFFSET(p[lo]);
7657 				*bad_sectors = BB_LEN(p[lo]);
7658 			}
7659 			lo--;
7660 		}
7661 	}
7662 
7663 	if (read_seqretry(&bb->lock, seq))
7664 		goto retry;
7665 
7666 	return rv;
7667 }
7668 EXPORT_SYMBOL_GPL(md_is_badblock);
7669 
7670 /*
7671  * Add a range of bad blocks to the table.
7672  * This might extend the table, or might contract it
7673  * if two adjacent ranges can be merged.
7674  * We binary-search to find the 'insertion' point, then
7675  * decide how best to handle it.
7676  */
7677 static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
7678 			    int acknowledged)
7679 {
7680 	u64 *p;
7681 	int lo, hi;
7682 	int rv = 1;
7683 
7684 	if (bb->shift < 0)
7685 		/* badblocks are disabled */
7686 		return 0;
7687 
7688 	if (bb->shift) {
7689 		/* round the start down, and the end up */
7690 		sector_t next = s + sectors;
7691 		s >>= bb->shift;
7692 		next += (1<<bb->shift) - 1;
7693 		next >>= bb->shift;
7694 		sectors = next - s;
7695 	}
7696 
7697 	write_seqlock_irq(&bb->lock);
7698 
7699 	p = bb->page;
7700 	lo = 0;
7701 	hi = bb->count;
7702 	/* Find the last range that starts at-or-before 's' */
7703 	while (hi - lo > 1) {
7704 		int mid = (lo + hi) / 2;
7705 		sector_t a = BB_OFFSET(p[mid]);
7706 		if (a <= s)
7707 			lo = mid;
7708 		else
7709 			hi = mid;
7710 	}
7711 	if (hi > lo && BB_OFFSET(p[lo]) > s)
7712 		hi = lo;
7713 
7714 	if (hi > lo) {
7715 		/* we found a range that might merge with the start
7716 		 * of our new range
7717 		 */
7718 		sector_t a = BB_OFFSET(p[lo]);
7719 		sector_t e = a + BB_LEN(p[lo]);
7720 		int ack = BB_ACK(p[lo]);
7721 		if (e >= s) {
7722 			/* Yes, we can merge with a previous range */
7723 			if (s == a && s + sectors >= e)
7724 				/* new range covers old */
7725 				ack = acknowledged;
7726 			else
7727 				ack = ack && acknowledged;
7728 
7729 			if (e < s + sectors)
7730 				e = s + sectors;
7731 			if (e - a <= BB_MAX_LEN) {
7732 				p[lo] = BB_MAKE(a, e-a, ack);
7733 				s = e;
7734 			} else {
7735 				/* does not all fit in one range,
7736 				 * make p[lo] maximal
7737 				 */
7738 				if (BB_LEN(p[lo]) != BB_MAX_LEN)
7739 					p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
7740 				s = a + BB_MAX_LEN;
7741 			}
7742 			sectors = e - s;
7743 		}
7744 	}
7745 	if (sectors && hi < bb->count) {
7746 		/* 'hi' points to the first range that starts after 's'.
7747 		 * Maybe we can merge with the start of that range */
7748 		sector_t a = BB_OFFSET(p[hi]);
7749 		sector_t e = a + BB_LEN(p[hi]);
7750 		int ack = BB_ACK(p[hi]);
7751 		if (a <= s + sectors) {
7752 			/* merging is possible */
7753 			if (e <= s + sectors) {
7754 				/* full overlap */
7755 				e = s + sectors;
7756 				ack = acknowledged;
7757 			} else
7758 				ack = ack && acknowledged;
7759 
7760 			a = s;
7761 			if (e - a <= BB_MAX_LEN) {
7762 				p[hi] = BB_MAKE(a, e-a, ack);
7763 				s = e;
7764 			} else {
7765 				p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
7766 				s = a + BB_MAX_LEN;
7767 			}
7768 			sectors = e - s;
7769 			lo = hi;
7770 			hi++;
7771 		}
7772 	}
7773 	if (sectors == 0 && hi < bb->count) {
7774 		/* we might be able to combine lo and hi */
7775 		/* Note: 's' is at the end of 'lo' */
7776 		sector_t a = BB_OFFSET(p[hi]);
7777 		int lolen = BB_LEN(p[lo]);
7778 		int hilen = BB_LEN(p[hi]);
7779 		int newlen = lolen + hilen - (s - a);
7780 		if (s >= a && newlen < BB_MAX_LEN) {
7781 			/* yes, we can combine them */
7782 			int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
7783 			p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
7784 			memmove(p + hi, p + hi + 1,
7785 				(bb->count - hi - 1) * 8);
7786 			bb->count--;
7787 		}
7788 	}
7789 	while (sectors) {
7790 		/* didn't merge (it all).
7791 		 * Need to add a range just before 'hi' */
7792 		if (bb->count >= MD_MAX_BADBLOCKS) {
7793 			/* No room for more */
7794 			rv = 0;
7795 			break;
7796 		} else {
7797 			int this_sectors = sectors;
7798 			memmove(p + hi + 1, p + hi,
7799 				(bb->count - hi) * 8);
7800 			bb->count++;
7801 
7802 			if (this_sectors > BB_MAX_LEN)
7803 				this_sectors = BB_MAX_LEN;
7804 			p[hi] = BB_MAKE(s, this_sectors, acknowledged);
7805 			sectors -= this_sectors;
7806 			s += this_sectors;
7807 		}
7808 	}
7809 
7810 	bb->changed = 1;
7811 	if (!acknowledged)
7812 		bb->unacked_exist = 1;
7813 	write_sequnlock_irq(&bb->lock);
7814 
7815 	return rv;
7816 }
7817 
7818 int rdev_set_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors,
7819 		       int acknowledged)
7820 {
7821 	int rv = md_set_badblocks(&rdev->badblocks,
7822 				  s + rdev->data_offset, sectors, acknowledged);
7823 	if (rv) {
7824 		/* Make sure they get written out promptly */
7825 		set_bit(MD_CHANGE_CLEAN, &rdev->mddev->flags);
7826 		md_wakeup_thread(rdev->mddev->thread);
7827 	}
7828 	return rv;
7829 }
7830 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
7831 
7832 /*
7833  * Remove a range of bad blocks from the table.
7834  * This may involve extending the table if we spilt a region,
7835  * but it must not fail.  So if the table becomes full, we just
7836  * drop the remove request.
7837  */
7838 static int md_clear_badblocks(struct badblocks *bb, sector_t s, int sectors)
7839 {
7840 	u64 *p;
7841 	int lo, hi;
7842 	sector_t target = s + sectors;
7843 	int rv = 0;
7844 
7845 	if (bb->shift > 0) {
7846 		/* When clearing we round the start up and the end down.
7847 		 * This should not matter as the shift should align with
7848 		 * the block size and no rounding should ever be needed.
7849 		 * However it is better the think a block is bad when it
7850 		 * isn't than to think a block is not bad when it is.
7851 		 */
7852 		s += (1<<bb->shift) - 1;
7853 		s >>= bb->shift;
7854 		target >>= bb->shift;
7855 		sectors = target - s;
7856 	}
7857 
7858 	write_seqlock_irq(&bb->lock);
7859 
7860 	p = bb->page;
7861 	lo = 0;
7862 	hi = bb->count;
7863 	/* Find the last range that starts before 'target' */
7864 	while (hi - lo > 1) {
7865 		int mid = (lo + hi) / 2;
7866 		sector_t a = BB_OFFSET(p[mid]);
7867 		if (a < target)
7868 			lo = mid;
7869 		else
7870 			hi = mid;
7871 	}
7872 	if (hi > lo) {
7873 		/* p[lo] is the last range that could overlap the
7874 		 * current range.  Earlier ranges could also overlap,
7875 		 * but only this one can overlap the end of the range.
7876 		 */
7877 		if (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) {
7878 			/* Partial overlap, leave the tail of this range */
7879 			int ack = BB_ACK(p[lo]);
7880 			sector_t a = BB_OFFSET(p[lo]);
7881 			sector_t end = a + BB_LEN(p[lo]);
7882 
7883 			if (a < s) {
7884 				/* we need to split this range */
7885 				if (bb->count >= MD_MAX_BADBLOCKS) {
7886 					rv = 0;
7887 					goto out;
7888 				}
7889 				memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
7890 				bb->count++;
7891 				p[lo] = BB_MAKE(a, s-a, ack);
7892 				lo++;
7893 			}
7894 			p[lo] = BB_MAKE(target, end - target, ack);
7895 			/* there is no longer an overlap */
7896 			hi = lo;
7897 			lo--;
7898 		}
7899 		while (lo >= 0 &&
7900 		       BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
7901 			/* This range does overlap */
7902 			if (BB_OFFSET(p[lo]) < s) {
7903 				/* Keep the early parts of this range. */
7904 				int ack = BB_ACK(p[lo]);
7905 				sector_t start = BB_OFFSET(p[lo]);
7906 				p[lo] = BB_MAKE(start, s - start, ack);
7907 				/* now low doesn't overlap, so.. */
7908 				break;
7909 			}
7910 			lo--;
7911 		}
7912 		/* 'lo' is strictly before, 'hi' is strictly after,
7913 		 * anything between needs to be discarded
7914 		 */
7915 		if (hi - lo > 1) {
7916 			memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
7917 			bb->count -= (hi - lo - 1);
7918 		}
7919 	}
7920 
7921 	bb->changed = 1;
7922 out:
7923 	write_sequnlock_irq(&bb->lock);
7924 	return rv;
7925 }
7926 
7927 int rdev_clear_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors)
7928 {
7929 	return md_clear_badblocks(&rdev->badblocks,
7930 				  s + rdev->data_offset,
7931 				  sectors);
7932 }
7933 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
7934 
7935 /*
7936  * Acknowledge all bad blocks in a list.
7937  * This only succeeds if ->changed is clear.  It is used by
7938  * in-kernel metadata updates
7939  */
7940 void md_ack_all_badblocks(struct badblocks *bb)
7941 {
7942 	if (bb->page == NULL || bb->changed)
7943 		/* no point even trying */
7944 		return;
7945 	write_seqlock_irq(&bb->lock);
7946 
7947 	if (bb->changed == 0) {
7948 		u64 *p = bb->page;
7949 		int i;
7950 		for (i = 0; i < bb->count ; i++) {
7951 			if (!BB_ACK(p[i])) {
7952 				sector_t start = BB_OFFSET(p[i]);
7953 				int len = BB_LEN(p[i]);
7954 				p[i] = BB_MAKE(start, len, 1);
7955 			}
7956 		}
7957 		bb->unacked_exist = 0;
7958 	}
7959 	write_sequnlock_irq(&bb->lock);
7960 }
7961 EXPORT_SYMBOL_GPL(md_ack_all_badblocks);
7962 
7963 /* sysfs access to bad-blocks list.
7964  * We present two files.
7965  * 'bad-blocks' lists sector numbers and lengths of ranges that
7966  *    are recorded as bad.  The list is truncated to fit within
7967  *    the one-page limit of sysfs.
7968  *    Writing "sector length" to this file adds an acknowledged
7969  *    bad block list.
7970  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
7971  *    been acknowledged.  Writing to this file adds bad blocks
7972  *    without acknowledging them.  This is largely for testing.
7973  */
7974 
7975 static ssize_t
7976 badblocks_show(struct badblocks *bb, char *page, int unack)
7977 {
7978 	size_t len;
7979 	int i;
7980 	u64 *p = bb->page;
7981 	unsigned seq;
7982 
7983 	if (bb->shift < 0)
7984 		return 0;
7985 
7986 retry:
7987 	seq = read_seqbegin(&bb->lock);
7988 
7989 	len = 0;
7990 	i = 0;
7991 
7992 	while (len < PAGE_SIZE && i < bb->count) {
7993 		sector_t s = BB_OFFSET(p[i]);
7994 		unsigned int length = BB_LEN(p[i]);
7995 		int ack = BB_ACK(p[i]);
7996 		i++;
7997 
7998 		if (unack && ack)
7999 			continue;
8000 
8001 		len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
8002 				(unsigned long long)s << bb->shift,
8003 				length << bb->shift);
8004 	}
8005 	if (unack && len == 0)
8006 		bb->unacked_exist = 0;
8007 
8008 	if (read_seqretry(&bb->lock, seq))
8009 		goto retry;
8010 
8011 	return len;
8012 }
8013 
8014 #define DO_DEBUG 1
8015 
8016 static ssize_t
8017 badblocks_store(struct badblocks *bb, const char *page, size_t len, int unack)
8018 {
8019 	unsigned long long sector;
8020 	int length;
8021 	char newline;
8022 #ifdef DO_DEBUG
8023 	/* Allow clearing via sysfs *only* for testing/debugging.
8024 	 * Normally only a successful write may clear a badblock
8025 	 */
8026 	int clear = 0;
8027 	if (page[0] == '-') {
8028 		clear = 1;
8029 		page++;
8030 	}
8031 #endif /* DO_DEBUG */
8032 
8033 	switch (sscanf(page, "%llu %d%c", &sector, &length, &newline)) {
8034 	case 3:
8035 		if (newline != '\n')
8036 			return -EINVAL;
8037 	case 2:
8038 		if (length <= 0)
8039 			return -EINVAL;
8040 		break;
8041 	default:
8042 		return -EINVAL;
8043 	}
8044 
8045 #ifdef DO_DEBUG
8046 	if (clear) {
8047 		md_clear_badblocks(bb, sector, length);
8048 		return len;
8049 	}
8050 #endif /* DO_DEBUG */
8051 	if (md_set_badblocks(bb, sector, length, !unack))
8052 		return len;
8053 	else
8054 		return -ENOSPC;
8055 }
8056 
8057 static int md_notify_reboot(struct notifier_block *this,
8058 			    unsigned long code, void *x)
8059 {
8060 	struct list_head *tmp;
8061 	mddev_t *mddev;
8062 
8063 	if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
8064 
8065 		printk(KERN_INFO "md: stopping all md devices.\n");
8066 
8067 		for_each_mddev(mddev, tmp)
8068 			if (mddev_trylock(mddev)) {
8069 				/* Force a switch to readonly even array
8070 				 * appears to still be in use.  Hence
8071 				 * the '100'.
8072 				 */
8073 				md_set_readonly(mddev, 100);
8074 				mddev_unlock(mddev);
8075 			}
8076 		/*
8077 		 * certain more exotic SCSI devices are known to be
8078 		 * volatile wrt too early system reboots. While the
8079 		 * right place to handle this issue is the given
8080 		 * driver, we do want to have a safe RAID driver ...
8081 		 */
8082 		mdelay(1000*1);
8083 	}
8084 	return NOTIFY_DONE;
8085 }
8086 
8087 static struct notifier_block md_notifier = {
8088 	.notifier_call	= md_notify_reboot,
8089 	.next		= NULL,
8090 	.priority	= INT_MAX, /* before any real devices */
8091 };
8092 
8093 static void md_geninit(void)
8094 {
8095 	dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
8096 
8097 	proc_create("mdstat", S_IRUGO, NULL, &md_seq_fops);
8098 }
8099 
8100 static int __init md_init(void)
8101 {
8102 	int ret = -ENOMEM;
8103 
8104 	md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
8105 	if (!md_wq)
8106 		goto err_wq;
8107 
8108 	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
8109 	if (!md_misc_wq)
8110 		goto err_misc_wq;
8111 
8112 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
8113 		goto err_md;
8114 
8115 	if ((ret = register_blkdev(0, "mdp")) < 0)
8116 		goto err_mdp;
8117 	mdp_major = ret;
8118 
8119 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
8120 			    md_probe, NULL, NULL);
8121 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
8122 			    md_probe, NULL, NULL);
8123 
8124 	register_reboot_notifier(&md_notifier);
8125 	raid_table_header = register_sysctl_table(raid_root_table);
8126 
8127 	md_geninit();
8128 	return 0;
8129 
8130 err_mdp:
8131 	unregister_blkdev(MD_MAJOR, "md");
8132 err_md:
8133 	destroy_workqueue(md_misc_wq);
8134 err_misc_wq:
8135 	destroy_workqueue(md_wq);
8136 err_wq:
8137 	return ret;
8138 }
8139 
8140 #ifndef MODULE
8141 
8142 /*
8143  * Searches all registered partitions for autorun RAID arrays
8144  * at boot time.
8145  */
8146 
8147 static LIST_HEAD(all_detected_devices);
8148 struct detected_devices_node {
8149 	struct list_head list;
8150 	dev_t dev;
8151 };
8152 
8153 void md_autodetect_dev(dev_t dev)
8154 {
8155 	struct detected_devices_node *node_detected_dev;
8156 
8157 	node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
8158 	if (node_detected_dev) {
8159 		node_detected_dev->dev = dev;
8160 		list_add_tail(&node_detected_dev->list, &all_detected_devices);
8161 	} else {
8162 		printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
8163 			", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
8164 	}
8165 }
8166 
8167 
8168 static void autostart_arrays(int part)
8169 {
8170 	mdk_rdev_t *rdev;
8171 	struct detected_devices_node *node_detected_dev;
8172 	dev_t dev;
8173 	int i_scanned, i_passed;
8174 
8175 	i_scanned = 0;
8176 	i_passed = 0;
8177 
8178 	printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
8179 
8180 	while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
8181 		i_scanned++;
8182 		node_detected_dev = list_entry(all_detected_devices.next,
8183 					struct detected_devices_node, list);
8184 		list_del(&node_detected_dev->list);
8185 		dev = node_detected_dev->dev;
8186 		kfree(node_detected_dev);
8187 		rdev = md_import_device(dev,0, 90);
8188 		if (IS_ERR(rdev))
8189 			continue;
8190 
8191 		if (test_bit(Faulty, &rdev->flags)) {
8192 			MD_BUG();
8193 			continue;
8194 		}
8195 		set_bit(AutoDetected, &rdev->flags);
8196 		list_add(&rdev->same_set, &pending_raid_disks);
8197 		i_passed++;
8198 	}
8199 
8200 	printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
8201 						i_scanned, i_passed);
8202 
8203 	autorun_devices(part);
8204 }
8205 
8206 #endif /* !MODULE */
8207 
8208 static __exit void md_exit(void)
8209 {
8210 	mddev_t *mddev;
8211 	struct list_head *tmp;
8212 
8213 	blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
8214 	blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
8215 
8216 	unregister_blkdev(MD_MAJOR,"md");
8217 	unregister_blkdev(mdp_major, "mdp");
8218 	unregister_reboot_notifier(&md_notifier);
8219 	unregister_sysctl_table(raid_table_header);
8220 	remove_proc_entry("mdstat", NULL);
8221 	for_each_mddev(mddev, tmp) {
8222 		export_array(mddev);
8223 		mddev->hold_active = 0;
8224 	}
8225 	destroy_workqueue(md_misc_wq);
8226 	destroy_workqueue(md_wq);
8227 }
8228 
8229 subsys_initcall(md_init);
8230 module_exit(md_exit)
8231 
8232 static int get_ro(char *buffer, struct kernel_param *kp)
8233 {
8234 	return sprintf(buffer, "%d", start_readonly);
8235 }
8236 static int set_ro(const char *val, struct kernel_param *kp)
8237 {
8238 	char *e;
8239 	int num = simple_strtoul(val, &e, 10);
8240 	if (*val && (*e == '\0' || *e == '\n')) {
8241 		start_readonly = num;
8242 		return 0;
8243 	}
8244 	return -EINVAL;
8245 }
8246 
8247 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
8248 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
8249 
8250 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
8251 
8252 EXPORT_SYMBOL(register_md_personality);
8253 EXPORT_SYMBOL(unregister_md_personality);
8254 EXPORT_SYMBOL(md_error);
8255 EXPORT_SYMBOL(md_done_sync);
8256 EXPORT_SYMBOL(md_write_start);
8257 EXPORT_SYMBOL(md_write_end);
8258 EXPORT_SYMBOL(md_register_thread);
8259 EXPORT_SYMBOL(md_unregister_thread);
8260 EXPORT_SYMBOL(md_wakeup_thread);
8261 EXPORT_SYMBOL(md_check_recovery);
8262 MODULE_LICENSE("GPL");
8263 MODULE_DESCRIPTION("MD RAID framework");
8264 MODULE_ALIAS("md");
8265 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
8266