raid5.c 78.2 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/*
 * raid5.c : Multiple Devices driver for Linux
 *	   Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
 *	   Copyright (C) 1999, 2000 Ingo Molnar
 *
 * RAID-5 management functions.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * You should have received a copy of the GNU General Public License
 * (for example /usr/src/linux/COPYING); if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/raid/raid5.h>
#include <linux/highmem.h>
#include <linux/bitops.h>
25
#include <linux/kthread.h>
L
Linus Torvalds 已提交
26 27
#include <asm/atomic.h>

28 29
#include <linux/raid/bitmap.h>

L
Linus Torvalds 已提交
30 31 32 33 34 35 36 37 38
/*
 * Stripe cache
 */

#define NR_STRIPES		256
#define STRIPE_SIZE		PAGE_SIZE
#define STRIPE_SHIFT		(PAGE_SHIFT - 9)
#define STRIPE_SECTORS		(STRIPE_SIZE>>9)
#define	IO_THRESHOLD		1
39
#define NR_HASH			(PAGE_SIZE / sizeof(struct hlist_head))
L
Linus Torvalds 已提交
40 41
#define HASH_MASK		(NR_HASH - 1)

42
#define stripe_hash(conf, sect)	(&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
L
Linus Torvalds 已提交
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

/* bio's attached to a stripe+device for I/O are linked together in bi_sector
 * order without overlap.  There may be several bio's per stripe+device, and
 * a bio could span several devices.
 * When walking this list for a particular stripe+device, we must never proceed
 * beyond a bio that extends past this device, as the next bio might no longer
 * be valid.
 * This macro is used to determine the 'next' bio in the list, given the sector
 * of the current stripe+device
 */
#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
/*
 * The following can be used to debug the driver
 */
#define RAID5_DEBUG	0
#define RAID5_PARANOIA	1
#if RAID5_PARANOIA && defined(CONFIG_SMP)
# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
#else
# define CHECK_DEVLOCK()
#endif

#define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x)))
#if RAID5_DEBUG
#define inline
#define __inline__
#endif

static void print_raid5_conf (raid5_conf_t *conf);

73
static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
L
Linus Torvalds 已提交
74 75
{
	if (atomic_dec_and_test(&sh->count)) {
76 77
		BUG_ON(!list_empty(&sh->lru));
		BUG_ON(atomic_read(&conf->active_stripes)==0);
L
Linus Torvalds 已提交
78 79 80
		if (test_bit(STRIPE_HANDLE, &sh->state)) {
			if (test_bit(STRIPE_DELAYED, &sh->state))
				list_add_tail(&sh->lru, &conf->delayed_list);
81 82 83 84 85
			else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
				 conf->seq_write == sh->bm_seq)
				list_add_tail(&sh->lru, &conf->bitmap_list);
			else {
				clear_bit(STRIPE_BIT_DELAY, &sh->state);
L
Linus Torvalds 已提交
86
				list_add_tail(&sh->lru, &conf->handle_list);
87
			}
L
Linus Torvalds 已提交
88 89 90 91 92 93 94 95
			md_wakeup_thread(conf->mddev->thread);
		} else {
			if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
				atomic_dec(&conf->preread_active_stripes);
				if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
					md_wakeup_thread(conf->mddev->thread);
			}
			atomic_dec(&conf->active_stripes);
96 97
			if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
				list_add_tail(&sh->lru, &conf->inactive_list);
L
Linus Torvalds 已提交
98
				wake_up(&conf->wait_for_stripe);
99
			}
L
Linus Torvalds 已提交
100 101 102 103 104 105 106 107 108 109 110 111 112
		}
	}
}
static void release_stripe(struct stripe_head *sh)
{
	raid5_conf_t *conf = sh->raid_conf;
	unsigned long flags;
	
	spin_lock_irqsave(&conf->device_lock, flags);
	__release_stripe(conf, sh);
	spin_unlock_irqrestore(&conf->device_lock, flags);
}

113
static inline void remove_hash(struct stripe_head *sh)
L
Linus Torvalds 已提交
114 115 116
{
	PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);

117
	hlist_del_init(&sh->hash);
L
Linus Torvalds 已提交
118 119
}

120
static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
L
Linus Torvalds 已提交
121
{
122
	struct hlist_head *hp = stripe_hash(conf, sh->sector);
L
Linus Torvalds 已提交
123 124 125 126

	PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);

	CHECK_DEVLOCK();
127
	hlist_add_head(&sh->hash, hp);
L
Linus Torvalds 已提交
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
}


/* find an idle stripe, make sure it is unhashed, and return it. */
static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
{
	struct stripe_head *sh = NULL;
	struct list_head *first;

	CHECK_DEVLOCK();
	if (list_empty(&conf->inactive_list))
		goto out;
	first = conf->inactive_list.next;
	sh = list_entry(first, struct stripe_head, lru);
	list_del_init(first);
	remove_hash(sh);
	atomic_inc(&conf->active_stripes);
out:
	return sh;
}

static void shrink_buffers(struct stripe_head *sh, int num)
{
	struct page *p;
	int i;

	for (i=0; i<num ; i++) {
		p = sh->dev[i].page;
		if (!p)
			continue;
		sh->dev[i].page = NULL;
159
		put_page(p);
L
Linus Torvalds 已提交
160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179
	}
}

static int grow_buffers(struct stripe_head *sh, int num)
{
	int i;

	for (i=0; i<num; i++) {
		struct page *page;

		if (!(page = alloc_page(GFP_KERNEL))) {
			return 1;
		}
		sh->dev[i].page = page;
	}
	return 0;
}

static void raid5_build_block (struct stripe_head *sh, int i);

180
static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
L
Linus Torvalds 已提交
181 182
{
	raid5_conf_t *conf = sh->raid_conf;
183
	int i;
L
Linus Torvalds 已提交
184

185 186
	BUG_ON(atomic_read(&sh->count) != 0);
	BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
L
Linus Torvalds 已提交
187 188 189 190 191 192 193 194 195 196 197
	
	CHECK_DEVLOCK();
	PRINTK("init_stripe called, stripe %llu\n", 
		(unsigned long long)sh->sector);

	remove_hash(sh);
	
	sh->sector = sector;
	sh->pd_idx = pd_idx;
	sh->state = 0;

198 199 200
	sh->disks = disks;

	for (i = sh->disks; i--; ) {
L
Linus Torvalds 已提交
201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216
		struct r5dev *dev = &sh->dev[i];

		if (dev->toread || dev->towrite || dev->written ||
		    test_bit(R5_LOCKED, &dev->flags)) {
			printk("sector=%llx i=%d %p %p %p %d\n",
			       (unsigned long long)sh->sector, i, dev->toread,
			       dev->towrite, dev->written,
			       test_bit(R5_LOCKED, &dev->flags));
			BUG();
		}
		dev->flags = 0;
		raid5_build_block(sh, i);
	}
	insert_hash(conf, sh);
}

217
static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
L
Linus Torvalds 已提交
218 219
{
	struct stripe_head *sh;
220
	struct hlist_node *hn;
L
Linus Torvalds 已提交
221 222 223

	CHECK_DEVLOCK();
	PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
224
	hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
225
		if (sh->sector == sector && sh->disks == disks)
L
Linus Torvalds 已提交
226 227 228 229 230 231 232 233
			return sh;
	PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
	return NULL;
}

static void unplug_slaves(mddev_t *mddev);
static void raid5_unplug_device(request_queue_t *q);

234 235
static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
					     int pd_idx, int noblock)
L
Linus Torvalds 已提交
236 237 238 239 240 241 242 243
{
	struct stripe_head *sh;

	PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector);

	spin_lock_irq(&conf->device_lock);

	do {
244 245 246
		wait_event_lock_irq(conf->wait_for_stripe,
				    conf->quiesce == 0,
				    conf->device_lock, /* nothing */);
247
		sh = __find_stripe(conf, sector, disks);
L
Linus Torvalds 已提交
248 249 250 251 252 253 254 255 256
		if (!sh) {
			if (!conf->inactive_blocked)
				sh = get_free_stripe(conf);
			if (noblock && sh == NULL)
				break;
			if (!sh) {
				conf->inactive_blocked = 1;
				wait_event_lock_irq(conf->wait_for_stripe,
						    !list_empty(&conf->inactive_list) &&
257 258
						    (atomic_read(&conf->active_stripes)
						     < (conf->max_nr_stripes *3/4)
L
Linus Torvalds 已提交
259 260
						     || !conf->inactive_blocked),
						    conf->device_lock,
261
						    unplug_slaves(conf->mddev)
L
Linus Torvalds 已提交
262 263 264
					);
				conf->inactive_blocked = 0;
			} else
265
				init_stripe(sh, sector, pd_idx, disks);
L
Linus Torvalds 已提交
266 267
		} else {
			if (atomic_read(&sh->count)) {
268
			  BUG_ON(!list_empty(&sh->lru));
L
Linus Torvalds 已提交
269 270 271
			} else {
				if (!test_bit(STRIPE_HANDLE, &sh->state))
					atomic_inc(&conf->active_stripes);
272 273
				if (!list_empty(&sh->lru))
					list_del_init(&sh->lru);
L
Linus Torvalds 已提交
274 275 276 277 278 279 280 281 282 283 284
			}
		}
	} while (sh == NULL);

	if (sh)
		atomic_inc(&sh->count);

	spin_unlock_irq(&conf->device_lock);
	return sh;
}

285
static int grow_one_stripe(raid5_conf_t *conf)
L
Linus Torvalds 已提交
286 287
{
	struct stripe_head *sh;
288 289 290 291 292 293 294 295 296 297 298 299
	sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
	if (!sh)
		return 0;
	memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
	sh->raid_conf = conf;
	spin_lock_init(&sh->lock);

	if (grow_buffers(sh, conf->raid_disks)) {
		shrink_buffers(sh, conf->raid_disks);
		kmem_cache_free(conf->slab_cache, sh);
		return 0;
	}
300
	sh->disks = conf->raid_disks;
301 302 303 304 305 306 307 308 309 310
	/* we just created an active stripe so... */
	atomic_set(&sh->count, 1);
	atomic_inc(&conf->active_stripes);
	INIT_LIST_HEAD(&sh->lru);
	release_stripe(sh);
	return 1;
}

static int grow_stripes(raid5_conf_t *conf, int num)
{
L
Linus Torvalds 已提交
311 312 313
	kmem_cache_t *sc;
	int devs = conf->raid_disks;

314 315 316 317
	sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev));
	sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev));
	conf->active_name = 0;
	sc = kmem_cache_create(conf->cache_name[conf->active_name],
L
Linus Torvalds 已提交
318 319 320 321 322
			       sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
			       0, 0, NULL, NULL);
	if (!sc)
		return 1;
	conf->slab_cache = sc;
323
	conf->pool_size = devs;
L
Linus Torvalds 已提交
324
	while (num--) {
325
		if (!grow_one_stripe(conf))
L
Linus Torvalds 已提交
326 327 328 329
			return 1;
	}
	return 0;
}
330 331

#ifdef CONFIG_MD_RAID5_RESHAPE
332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404
static int resize_stripes(raid5_conf_t *conf, int newsize)
{
	/* Make all the stripes able to hold 'newsize' devices.
	 * New slots in each stripe get 'page' set to a new page.
	 *
	 * This happens in stages:
	 * 1/ create a new kmem_cache and allocate the required number of
	 *    stripe_heads.
	 * 2/ gather all the old stripe_heads and tranfer the pages across
	 *    to the new stripe_heads.  This will have the side effect of
	 *    freezing the array as once all stripe_heads have been collected,
	 *    no IO will be possible.  Old stripe heads are freed once their
	 *    pages have been transferred over, and the old kmem_cache is
	 *    freed when all stripes are done.
	 * 3/ reallocate conf->disks to be suitable bigger.  If this fails,
	 *    we simple return a failre status - no need to clean anything up.
	 * 4/ allocate new pages for the new slots in the new stripe_heads.
	 *    If this fails, we don't bother trying the shrink the
	 *    stripe_heads down again, we just leave them as they are.
	 *    As each stripe_head is processed the new one is released into
	 *    active service.
	 *
	 * Once step2 is started, we cannot afford to wait for a write,
	 * so we use GFP_NOIO allocations.
	 */
	struct stripe_head *osh, *nsh;
	LIST_HEAD(newstripes);
	struct disk_info *ndisks;
	int err = 0;
	kmem_cache_t *sc;
	int i;

	if (newsize <= conf->pool_size)
		return 0; /* never bother to shrink */

	/* Step 1 */
	sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
			       sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
			       0, 0, NULL, NULL);
	if (!sc)
		return -ENOMEM;

	for (i = conf->max_nr_stripes; i; i--) {
		nsh = kmem_cache_alloc(sc, GFP_KERNEL);
		if (!nsh)
			break;

		memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));

		nsh->raid_conf = conf;
		spin_lock_init(&nsh->lock);

		list_add(&nsh->lru, &newstripes);
	}
	if (i) {
		/* didn't get enough, give up */
		while (!list_empty(&newstripes)) {
			nsh = list_entry(newstripes.next, struct stripe_head, lru);
			list_del(&nsh->lru);
			kmem_cache_free(sc, nsh);
		}
		kmem_cache_destroy(sc);
		return -ENOMEM;
	}
	/* Step 2 - Must use GFP_NOIO now.
	 * OK, we have enough stripes, start collecting inactive
	 * stripes and copying them over
	 */
	list_for_each_entry(nsh, &newstripes, lru) {
		spin_lock_irq(&conf->device_lock);
		wait_event_lock_irq(conf->wait_for_stripe,
				    !list_empty(&conf->inactive_list),
				    conf->device_lock,
405
				    unplug_slaves(conf->mddev)
406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451
			);
		osh = get_free_stripe(conf);
		spin_unlock_irq(&conf->device_lock);
		atomic_set(&nsh->count, 1);
		for(i=0; i<conf->pool_size; i++)
			nsh->dev[i].page = osh->dev[i].page;
		for( ; i<newsize; i++)
			nsh->dev[i].page = NULL;
		kmem_cache_free(conf->slab_cache, osh);
	}
	kmem_cache_destroy(conf->slab_cache);

	/* Step 3.
	 * At this point, we are holding all the stripes so the array
	 * is completely stalled, so now is a good time to resize
	 * conf->disks.
	 */
	ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
	if (ndisks) {
		for (i=0; i<conf->raid_disks; i++)
			ndisks[i] = conf->disks[i];
		kfree(conf->disks);
		conf->disks = ndisks;
	} else
		err = -ENOMEM;

	/* Step 4, return new stripes to service */
	while(!list_empty(&newstripes)) {
		nsh = list_entry(newstripes.next, struct stripe_head, lru);
		list_del_init(&nsh->lru);
		for (i=conf->raid_disks; i < newsize; i++)
			if (nsh->dev[i].page == NULL) {
				struct page *p = alloc_page(GFP_NOIO);
				nsh->dev[i].page = p;
				if (!p)
					err = -ENOMEM;
			}
		release_stripe(nsh);
	}
	/* critical section pass, GFP_NOIO no longer needed */

	conf->slab_cache = sc;
	conf->active_name = 1-conf->active_name;
	conf->pool_size = newsize;
	return err;
}
452
#endif
L
Linus Torvalds 已提交
453

454
static int drop_one_stripe(raid5_conf_t *conf)
L
Linus Torvalds 已提交
455 456 457
{
	struct stripe_head *sh;

458 459 460 461 462
	spin_lock_irq(&conf->device_lock);
	sh = get_free_stripe(conf);
	spin_unlock_irq(&conf->device_lock);
	if (!sh)
		return 0;
463
	BUG_ON(atomic_read(&sh->count));
464
	shrink_buffers(sh, conf->pool_size);
465 466 467 468 469 470 471 472 473 474
	kmem_cache_free(conf->slab_cache, sh);
	atomic_dec(&conf->active_stripes);
	return 1;
}

static void shrink_stripes(raid5_conf_t *conf)
{
	while (drop_one_stripe(conf))
		;

N
NeilBrown 已提交
475 476
	if (conf->slab_cache)
		kmem_cache_destroy(conf->slab_cache);
L
Linus Torvalds 已提交
477 478 479
	conf->slab_cache = NULL;
}

480
static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
L
Linus Torvalds 已提交
481 482 483 484
				   int error)
{
 	struct stripe_head *sh = bi->bi_private;
	raid5_conf_t *conf = sh->raid_conf;
485
	int disks = sh->disks, i;
L
Linus Torvalds 已提交
486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
	int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);

	if (bi->bi_size)
		return 1;

	for (i=0 ; i<disks; i++)
		if (bi == &sh->dev[i].req)
			break;

	PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", 
		(unsigned long long)sh->sector, i, atomic_read(&sh->count), 
		uptodate);
	if (i == disks) {
		BUG();
		return 0;
	}

	if (uptodate) {
#if 0
		struct bio *bio;
		unsigned long flags;
		spin_lock_irqsave(&conf->device_lock, flags);
		/* we can return a buffer if we bypassed the cache or
		 * if the top buffer is not in highmem.  If there are
		 * multiple buffers, leave the extra work to
		 * handle_stripe
		 */
		buffer = sh->bh_read[i];
		if (buffer &&
		    (!PageHighMem(buffer->b_page)
		     || buffer->b_page == bh->b_page )
			) {
			sh->bh_read[i] = buffer->b_reqnext;
			buffer->b_reqnext = NULL;
		} else
			buffer = NULL;
		spin_unlock_irqrestore(&conf->device_lock, flags);
		if (sh->bh_page[i]==bh->b_page)
			set_buffer_uptodate(bh);
		if (buffer) {
			if (buffer->b_page != bh->b_page)
				memcpy(buffer->b_data, bh->b_data, bh->b_size);
			buffer->b_end_io(buffer, 1);
		}
#else
		set_bit(R5_UPTODATE, &sh->dev[i].flags);
532 533
#endif
		if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
N
NeilBrown 已提交
534
			printk(KERN_INFO "raid5: read error corrected!!\n");
535 536 537
			clear_bit(R5_ReadError, &sh->dev[i].flags);
			clear_bit(R5_ReWrite, &sh->dev[i].flags);
		}
538 539
		if (atomic_read(&conf->disks[i].rdev->read_errors))
			atomic_set(&conf->disks[i].rdev->read_errors, 0);
L
Linus Torvalds 已提交
540
	} else {
541
		int retry = 0;
L
Linus Torvalds 已提交
542
		clear_bit(R5_UPTODATE, &sh->dev[i].flags);
543 544
		atomic_inc(&conf->disks[i].rdev->read_errors);
		if (conf->mddev->degraded)
N
NeilBrown 已提交
545
			printk(KERN_WARNING "raid5: read error not correctable.\n");
546
		else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
547
			/* Oh, no!!! */
N
NeilBrown 已提交
548
			printk(KERN_WARNING "raid5: read error NOT corrected!!\n");
549 550
		else if (atomic_read(&conf->disks[i].rdev->read_errors)
			 > conf->max_nr_stripes)
N
NeilBrown 已提交
551 552
			printk(KERN_WARNING
			       "raid5: Too many read errors, failing device.\n");
553 554 555 556 557
		else
			retry = 1;
		if (retry)
			set_bit(R5_ReadError, &sh->dev[i].flags);
		else {
558 559 560
			clear_bit(R5_ReadError, &sh->dev[i].flags);
			clear_bit(R5_ReWrite, &sh->dev[i].flags);
			md_error(conf->mddev, conf->disks[i].rdev);
561
		}
L
Linus Torvalds 已提交
562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582
	}
	rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
#if 0
	/* must restore b_page before unlocking buffer... */
	if (sh->bh_page[i] != bh->b_page) {
		bh->b_page = sh->bh_page[i];
		bh->b_data = page_address(bh->b_page);
		clear_buffer_uptodate(bh);
	}
#endif
	clear_bit(R5_LOCKED, &sh->dev[i].flags);
	set_bit(STRIPE_HANDLE, &sh->state);
	release_stripe(sh);
	return 0;
}

static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
				    int error)
{
 	struct stripe_head *sh = bi->bi_private;
	raid5_conf_t *conf = sh->raid_conf;
583
	int disks = sh->disks, i;
L
Linus Torvalds 已提交
584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
	unsigned long flags;
	int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);

	if (bi->bi_size)
		return 1;

	for (i=0 ; i<disks; i++)
		if (bi == &sh->dev[i].req)
			break;

	PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", 
		(unsigned long long)sh->sector, i, atomic_read(&sh->count),
		uptodate);
	if (i == disks) {
		BUG();
		return 0;
	}

	spin_lock_irqsave(&conf->device_lock, flags);
	if (!uptodate)
		md_error(conf->mddev, conf->disks[i].rdev);

	rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
	
	clear_bit(R5_LOCKED, &sh->dev[i].flags);
	set_bit(STRIPE_HANDLE, &sh->state);
	__release_stripe(conf, sh);
	spin_unlock_irqrestore(&conf->device_lock, flags);
	return 0;
}


static sector_t compute_blocknr(struct stripe_head *sh, int i);
	
static void raid5_build_block (struct stripe_head *sh, int i)
{
	struct r5dev *dev = &sh->dev[i];

	bio_init(&dev->req);
	dev->req.bi_io_vec = &dev->vec;
	dev->req.bi_vcnt++;
	dev->req.bi_max_vecs++;
	dev->vec.bv_page = dev->page;
	dev->vec.bv_len = STRIPE_SIZE;
	dev->vec.bv_offset = 0;

	dev->req.bi_sector = sh->sector;
	dev->req.bi_private = sh;

	dev->flags = 0;
	if (i != sh->pd_idx)
		dev->sector = compute_blocknr(sh, i);
}

static void error(mddev_t *mddev, mdk_rdev_t *rdev)
{
	char b[BDEVNAME_SIZE];
	raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
	PRINTK("raid5: error called\n");

644
	if (!test_bit(Faulty, &rdev->flags)) {
L
Linus Torvalds 已提交
645
		mddev->sb_dirty = 1;
646
		if (test_bit(In_sync, &rdev->flags)) {
L
Linus Torvalds 已提交
647 648 649
			conf->working_disks--;
			mddev->degraded++;
			conf->failed_disks++;
650
			clear_bit(In_sync, &rdev->flags);
L
Linus Torvalds 已提交
651 652 653 654 655
			/*
			 * if recovery was running, make sure it aborts.
			 */
			set_bit(MD_RECOVERY_ERR, &mddev->recovery);
		}
656
		set_bit(Faulty, &rdev->flags);
L
Linus Torvalds 已提交
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721
		printk (KERN_ALERT
			"raid5: Disk failure on %s, disabling device."
			" Operation continuing on %d devices\n",
			bdevname(rdev->bdev,b), conf->working_disks);
	}
}	

/*
 * Input: a 'big' sector number,
 * Output: index of the data and parity disk, and the sector # in them.
 */
static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
			unsigned int data_disks, unsigned int * dd_idx,
			unsigned int * pd_idx, raid5_conf_t *conf)
{
	long stripe;
	unsigned long chunk_number;
	unsigned int chunk_offset;
	sector_t new_sector;
	int sectors_per_chunk = conf->chunk_size >> 9;

	/* First compute the information on this sector */

	/*
	 * Compute the chunk number and the sector offset inside the chunk
	 */
	chunk_offset = sector_div(r_sector, sectors_per_chunk);
	chunk_number = r_sector;
	BUG_ON(r_sector != chunk_number);

	/*
	 * Compute the stripe number
	 */
	stripe = chunk_number / data_disks;

	/*
	 * Compute the data disk and parity disk indexes inside the stripe
	 */
	*dd_idx = chunk_number % data_disks;

	/*
	 * Select the parity disk based on the user selected algorithm.
	 */
	if (conf->level == 4)
		*pd_idx = data_disks;
	else switch (conf->algorithm) {
		case ALGORITHM_LEFT_ASYMMETRIC:
			*pd_idx = data_disks - stripe % raid_disks;
			if (*dd_idx >= *pd_idx)
				(*dd_idx)++;
			break;
		case ALGORITHM_RIGHT_ASYMMETRIC:
			*pd_idx = stripe % raid_disks;
			if (*dd_idx >= *pd_idx)
				(*dd_idx)++;
			break;
		case ALGORITHM_LEFT_SYMMETRIC:
			*pd_idx = data_disks - stripe % raid_disks;
			*dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
			break;
		case ALGORITHM_RIGHT_SYMMETRIC:
			*pd_idx = stripe % raid_disks;
			*dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
			break;
		default:
N
NeilBrown 已提交
722
			printk(KERN_ERR "raid5: unsupported algorithm %d\n",
L
Linus Torvalds 已提交
723 724 725 726 727 728 729 730 731 732 733 734 735 736
				conf->algorithm);
	}

	/*
	 * Finally, compute the new sector number
	 */
	new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
	return new_sector;
}


static sector_t compute_blocknr(struct stripe_head *sh, int i)
{
	raid5_conf_t *conf = sh->raid_conf;
737
	int raid_disks = sh->disks, data_disks = raid_disks - 1;
L
Linus Torvalds 已提交
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762
	sector_t new_sector = sh->sector, check;
	int sectors_per_chunk = conf->chunk_size >> 9;
	sector_t stripe;
	int chunk_offset;
	int chunk_number, dummy1, dummy2, dd_idx = i;
	sector_t r_sector;

	chunk_offset = sector_div(new_sector, sectors_per_chunk);
	stripe = new_sector;
	BUG_ON(new_sector != stripe);

	
	switch (conf->algorithm) {
		case ALGORITHM_LEFT_ASYMMETRIC:
		case ALGORITHM_RIGHT_ASYMMETRIC:
			if (i > sh->pd_idx)
				i--;
			break;
		case ALGORITHM_LEFT_SYMMETRIC:
		case ALGORITHM_RIGHT_SYMMETRIC:
			if (i < sh->pd_idx)
				i += raid_disks;
			i -= (sh->pd_idx + 1);
			break;
		default:
N
NeilBrown 已提交
763
			printk(KERN_ERR "raid5: unsupported algorithm %d\n",
L
Linus Torvalds 已提交
764 765 766 767 768 769 770 771
				conf->algorithm);
	}

	chunk_number = stripe * data_disks + i;
	r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;

	check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
	if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
N
NeilBrown 已提交
772
		printk(KERN_ERR "compute_blocknr: map not correct\n");
L
Linus Torvalds 已提交
773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
		return 0;
	}
	return r_sector;
}



/*
 * Copy data between a page in the stripe cache, and a bio.
 * There are no alignment or size guarantees between the page or the
 * bio except that there is some overlap.
 * All iovecs in the bio must be considered.
 */
static void copy_data(int frombio, struct bio *bio,
		     struct page *page,
		     sector_t sector)
{
	char *pa = page_address(page);
	struct bio_vec *bvl;
	int i;
	int page_offset;

	if (bio->bi_sector >= sector)
		page_offset = (signed)(bio->bi_sector - sector) * 512;
	else
		page_offset = (signed)(sector - bio->bi_sector) * -512;
	bio_for_each_segment(bvl, bio, i) {
		int len = bio_iovec_idx(bio,i)->bv_len;
		int clen;
		int b_offset = 0;

		if (page_offset < 0) {
			b_offset = -page_offset;
			page_offset += b_offset;
			len -= b_offset;
		}

		if (len > 0 && page_offset + len > STRIPE_SIZE)
			clen = STRIPE_SIZE - page_offset;
		else clen = len;
			
		if (clen > 0) {
			char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
			if (frombio)
				memcpy(pa+page_offset, ba+b_offset, clen);
			else
				memcpy(ba+b_offset, pa+page_offset, clen);
			__bio_kunmap_atomic(ba, KM_USER0);
		}
		if (clen < len) /* hit end of page */
			break;
		page_offset +=  len;
	}
}

#define check_xor() 	do { 						\
			   if (count == MAX_XOR_BLOCKS) {		\
				xor_block(count, STRIPE_SIZE, ptr);	\
				count = 1;				\
			   }						\
			} while(0)


static void compute_block(struct stripe_head *sh, int dd_idx)
{
838
	int i, count, disks = sh->disks;
L
Linus Torvalds 已提交
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853
	void *ptr[MAX_XOR_BLOCKS], *p;

	PRINTK("compute_block, stripe %llu, idx %d\n", 
		(unsigned long long)sh->sector, dd_idx);

	ptr[0] = page_address(sh->dev[dd_idx].page);
	memset(ptr[0], 0, STRIPE_SIZE);
	count = 1;
	for (i = disks ; i--; ) {
		if (i == dd_idx)
			continue;
		p = page_address(sh->dev[i].page);
		if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
			ptr[count++] = p;
		else
N
NeilBrown 已提交
854
			printk(KERN_ERR "compute_block() %d, stripe %llu, %d"
L
Linus Torvalds 已提交
855 856 857 858 859 860 861 862 863 864 865 866 867
				" not present\n", dd_idx,
				(unsigned long long)sh->sector, i);

		check_xor();
	}
	if (count != 1)
		xor_block(count, STRIPE_SIZE, ptr);
	set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
}

static void compute_parity(struct stripe_head *sh, int method)
{
	raid5_conf_t *conf = sh->raid_conf;
868
	int i, pd_idx = sh->pd_idx, disks = sh->disks, count;
L
Linus Torvalds 已提交
869 870 871 872 873 874 875 876 877 878
	void *ptr[MAX_XOR_BLOCKS];
	struct bio *chosen;

	PRINTK("compute_parity, stripe %llu, method %d\n",
		(unsigned long long)sh->sector, method);

	count = 1;
	ptr[0] = page_address(sh->dev[pd_idx].page);
	switch(method) {
	case READ_MODIFY_WRITE:
879
		BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags));
L
Linus Torvalds 已提交
880 881 882 883 884 885 886 887 888 889 890 891
		for (i=disks ; i-- ;) {
			if (i==pd_idx)
				continue;
			if (sh->dev[i].towrite &&
			    test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
				ptr[count++] = page_address(sh->dev[i].page);
				chosen = sh->dev[i].towrite;
				sh->dev[i].towrite = NULL;

				if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
					wake_up(&conf->wait_for_overlap);

892
				BUG_ON(sh->dev[i].written);
L
Linus Torvalds 已提交
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907
				sh->dev[i].written = chosen;
				check_xor();
			}
		}
		break;
	case RECONSTRUCT_WRITE:
		memset(ptr[0], 0, STRIPE_SIZE);
		for (i= disks; i-- ;)
			if (i!=pd_idx && sh->dev[i].towrite) {
				chosen = sh->dev[i].towrite;
				sh->dev[i].towrite = NULL;

				if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
					wake_up(&conf->wait_for_overlap);

908
				BUG_ON(sh->dev[i].written);
L
Linus Torvalds 已提交
909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967
				sh->dev[i].written = chosen;
			}
		break;
	case CHECK_PARITY:
		break;
	}
	if (count>1) {
		xor_block(count, STRIPE_SIZE, ptr);
		count = 1;
	}
	
	for (i = disks; i--;)
		if (sh->dev[i].written) {
			sector_t sector = sh->dev[i].sector;
			struct bio *wbi = sh->dev[i].written;
			while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
				copy_data(1, wbi, sh->dev[i].page, sector);
				wbi = r5_next_bio(wbi, sector);
			}

			set_bit(R5_LOCKED, &sh->dev[i].flags);
			set_bit(R5_UPTODATE, &sh->dev[i].flags);
		}

	switch(method) {
	case RECONSTRUCT_WRITE:
	case CHECK_PARITY:
		for (i=disks; i--;)
			if (i != pd_idx) {
				ptr[count++] = page_address(sh->dev[i].page);
				check_xor();
			}
		break;
	case READ_MODIFY_WRITE:
		for (i = disks; i--;)
			if (sh->dev[i].written) {
				ptr[count++] = page_address(sh->dev[i].page);
				check_xor();
			}
	}
	if (count != 1)
		xor_block(count, STRIPE_SIZE, ptr);
	
	if (method != CHECK_PARITY) {
		set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
		set_bit(R5_LOCKED,   &sh->dev[pd_idx].flags);
	} else
		clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
}

/*
 * Each stripe/dev can have one or more bion attached.
 * toread/towrite point to the first in a chain. 
 * The bi_next chain must be in order.
 */
static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
{
	struct bio **bip;
	raid5_conf_t *conf = sh->raid_conf;
968
	int firstwrite=0;
L
Linus Torvalds 已提交
969 970 971 972 973 974 975 976

	PRINTK("adding bh b#%llu to stripe s#%llu\n",
		(unsigned long long)bi->bi_sector,
		(unsigned long long)sh->sector);


	spin_lock(&sh->lock);
	spin_lock_irq(&conf->device_lock);
977
	if (forwrite) {
L
Linus Torvalds 已提交
978
		bip = &sh->dev[dd_idx].towrite;
979 980 981
		if (*bip == NULL && sh->dev[dd_idx].written == NULL)
			firstwrite = 1;
	} else
L
Linus Torvalds 已提交
982 983 984 985 986 987 988 989 990
		bip = &sh->dev[dd_idx].toread;
	while (*bip && (*bip)->bi_sector < bi->bi_sector) {
		if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
			goto overlap;
		bip = & (*bip)->bi_next;
	}
	if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
		goto overlap;

991
	BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
L
Linus Torvalds 已提交
992 993 994 995 996 997 998 999 1000 1001 1002
	if (*bip)
		bi->bi_next = *bip;
	*bip = bi;
	bi->bi_phys_segments ++;
	spin_unlock_irq(&conf->device_lock);
	spin_unlock(&sh->lock);

	PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
		(unsigned long long)bi->bi_sector,
		(unsigned long long)sh->sector, dd_idx);

1003 1004 1005 1006 1007 1008 1009
	if (conf->mddev->bitmap && firstwrite) {
		sh->bm_seq = conf->seq_write;
		bitmap_startwrite(conf->mddev->bitmap, sh->sector,
				  STRIPE_SECTORS, 0);
		set_bit(STRIPE_BIT_DELAY, &sh->state);
	}

L
Linus Torvalds 已提交
1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
	if (forwrite) {
		/* check if page is covered */
		sector_t sector = sh->dev[dd_idx].sector;
		for (bi=sh->dev[dd_idx].towrite;
		     sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
			     bi && bi->bi_sector <= sector;
		     bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
			if (bi->bi_sector + (bi->bi_size>>9) >= sector)
				sector = bi->bi_sector + (bi->bi_size>>9);
		}
		if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
			set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
	}
	return 1;

 overlap:
	set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
	spin_unlock_irq(&conf->device_lock);
	spin_unlock(&sh->lock);
	return 0;
}

1032 1033
static void end_reshape(raid5_conf_t *conf);

1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
{
	int sectors_per_chunk = conf->chunk_size >> 9;
	sector_t x = stripe;
	int pd_idx, dd_idx;
	int chunk_offset = sector_div(x, sectors_per_chunk);
	stripe = x;
	raid5_compute_sector(stripe*(disks-1)*sectors_per_chunk
			     + chunk_offset, disks, disks-1, &dd_idx, &pd_idx, conf);
	return pd_idx;
}

L
Linus Torvalds 已提交
1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067

/*
 * handle_stripe - do things to a stripe.
 *
 * We lock the stripe and then examine the state of various bits
 * to see what needs to be done.
 * Possible results:
 *    return some read request which now have data
 *    return some write requests which are safely on disc
 *    schedule a read on some buffers
 *    schedule a write of some buffers
 *    return confirmation of parity correctness
 *
 * Parity calculations are done inside the stripe lock
 * buffers are taken off read_list or write_list, and bh_cache buffers
 * get BH_Lock set before the stripe lock is released.
 *
 */
 
static void handle_stripe(struct stripe_head *sh)
{
	raid5_conf_t *conf = sh->raid_conf;
1068
	int disks = sh->disks;
L
Linus Torvalds 已提交
1069 1070 1071
	struct bio *return_bi= NULL;
	struct bio *bi;
	int i;
1072
	int syncing, expanding, expanded;
L
Linus Torvalds 已提交
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
	int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
	int non_overwrite = 0;
	int failed_num=0;
	struct r5dev *dev;

	PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
		(unsigned long long)sh->sector, atomic_read(&sh->count),
		sh->pd_idx);

	spin_lock(&sh->lock);
	clear_bit(STRIPE_HANDLE, &sh->state);
	clear_bit(STRIPE_DELAYED, &sh->state);

	syncing = test_bit(STRIPE_SYNCING, &sh->state);
1087 1088
	expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
	expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
L
Linus Torvalds 已提交
1089 1090
	/* Now to look around and see what can be done */

1091
	rcu_read_lock();
L
Linus Torvalds 已提交
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133
	for (i=disks; i--; ) {
		mdk_rdev_t *rdev;
		dev = &sh->dev[i];
		clear_bit(R5_Insync, &dev->flags);

		PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
			i, dev->flags, dev->toread, dev->towrite, dev->written);
		/* maybe we can reply to a read */
		if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
			struct bio *rbi, *rbi2;
			PRINTK("Return read for disc %d\n", i);
			spin_lock_irq(&conf->device_lock);
			rbi = dev->toread;
			dev->toread = NULL;
			if (test_and_clear_bit(R5_Overlap, &dev->flags))
				wake_up(&conf->wait_for_overlap);
			spin_unlock_irq(&conf->device_lock);
			while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
				copy_data(0, rbi, dev->page, dev->sector);
				rbi2 = r5_next_bio(rbi, dev->sector);
				spin_lock_irq(&conf->device_lock);
				if (--rbi->bi_phys_segments == 0) {
					rbi->bi_next = return_bi;
					return_bi = rbi;
				}
				spin_unlock_irq(&conf->device_lock);
				rbi = rbi2;
			}
		}

		/* now count some things */
		if (test_bit(R5_LOCKED, &dev->flags)) locked++;
		if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;

		
		if (dev->toread) to_read++;
		if (dev->towrite) {
			to_write++;
			if (!test_bit(R5_OVERWRITE, &dev->flags))
				non_overwrite++;
		}
		if (dev->written) written++;
1134
		rdev = rcu_dereference(conf->disks[i].rdev);
1135
		if (!rdev || !test_bit(In_sync, &rdev->flags)) {
N
NeilBrown 已提交
1136
			/* The ReadError flag will just be confusing now */
1137 1138 1139
			clear_bit(R5_ReadError, &dev->flags);
			clear_bit(R5_ReWrite, &dev->flags);
		}
1140
		if (!rdev || !test_bit(In_sync, &rdev->flags)
1141
		    || test_bit(R5_ReadError, &dev->flags)) {
L
Linus Torvalds 已提交
1142 1143 1144 1145 1146
			failed++;
			failed_num = i;
		} else
			set_bit(R5_Insync, &dev->flags);
	}
1147
	rcu_read_unlock();
L
Linus Torvalds 已提交
1148 1149 1150 1151 1152 1153 1154 1155
	PRINTK("locked=%d uptodate=%d to_read=%d"
		" to_write=%d failed=%d failed_num=%d\n",
		locked, uptodate, to_read, to_write, failed, failed_num);
	/* check if the array has lost two devices and, if so, some requests might
	 * need to be failed
	 */
	if (failed > 1 && to_read+to_write+written) {
		for (i=disks; i--; ) {
1156
			int bitmap_end = 0;
1157 1158

			if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1159 1160 1161
				mdk_rdev_t *rdev;
				rcu_read_lock();
				rdev = rcu_dereference(conf->disks[i].rdev);
1162
				if (rdev && test_bit(In_sync, &rdev->flags))
1163 1164
					/* multiple read failures in one stripe */
					md_error(conf->mddev, rdev);
1165
				rcu_read_unlock();
1166 1167
			}

1168
			spin_lock_irq(&conf->device_lock);
L
Linus Torvalds 已提交
1169 1170 1171
			/* fail all writes first */
			bi = sh->dev[i].towrite;
			sh->dev[i].towrite = NULL;
1172
			if (bi) { to_write--; bitmap_end = 1; }
L
Linus Torvalds 已提交
1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189

			if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
				wake_up(&conf->wait_for_overlap);

			while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
				struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
				clear_bit(BIO_UPTODATE, &bi->bi_flags);
				if (--bi->bi_phys_segments == 0) {
					md_write_end(conf->mddev);
					bi->bi_next = return_bi;
					return_bi = bi;
				}
				bi = nextbi;
			}
			/* and fail all 'written' */
			bi = sh->dev[i].written;
			sh->dev[i].written = NULL;
1190
			if (bi) bitmap_end = 1;
L
Linus Torvalds 已提交
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
			while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
				struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
				clear_bit(BIO_UPTODATE, &bi->bi_flags);
				if (--bi->bi_phys_segments == 0) {
					md_write_end(conf->mddev);
					bi->bi_next = return_bi;
					return_bi = bi;
				}
				bi = bi2;
			}

			/* fail any reads if this device is non-operational */
1203 1204
			if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
			    test_bit(R5_ReadError, &sh->dev[i].flags)) {
L
Linus Torvalds 已提交
1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219
				bi = sh->dev[i].toread;
				sh->dev[i].toread = NULL;
				if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
					wake_up(&conf->wait_for_overlap);
				if (bi) to_read--;
				while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
					struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
					clear_bit(BIO_UPTODATE, &bi->bi_flags);
					if (--bi->bi_phys_segments == 0) {
						bi->bi_next = return_bi;
						return_bi = bi;
					}
					bi = nextbi;
				}
			}
1220 1221 1222 1223
			spin_unlock_irq(&conf->device_lock);
			if (bitmap_end)
				bitmap_endwrite(conf->mddev->bitmap, sh->sector,
						STRIPE_SECTORS, 0, 0);
L
Linus Torvalds 已提交
1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251
		}
	}
	if (failed > 1 && syncing) {
		md_done_sync(conf->mddev, STRIPE_SECTORS,0);
		clear_bit(STRIPE_SYNCING, &sh->state);
		syncing = 0;
	}

	/* might be able to return some write requests if the parity block
	 * is safe, or on a failed drive
	 */
	dev = &sh->dev[sh->pd_idx];
	if ( written &&
	     ( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) &&
		test_bit(R5_UPTODATE, &dev->flags))
	       || (failed == 1 && failed_num == sh->pd_idx))
	    ) {
	    /* any written block on an uptodate or failed drive can be returned.
	     * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 
	     * never LOCKED, so we don't need to test 'failed' directly.
	     */
	    for (i=disks; i--; )
		if (sh->dev[i].written) {
		    dev = &sh->dev[i];
		    if (!test_bit(R5_LOCKED, &dev->flags) &&
			 test_bit(R5_UPTODATE, &dev->flags) ) {
			/* We can return any write requests */
			    struct bio *wbi, *wbi2;
1252
			    int bitmap_end = 0;
L
Linus Torvalds 已提交
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
			    PRINTK("Return write for disc %d\n", i);
			    spin_lock_irq(&conf->device_lock);
			    wbi = dev->written;
			    dev->written = NULL;
			    while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
				    wbi2 = r5_next_bio(wbi, dev->sector);
				    if (--wbi->bi_phys_segments == 0) {
					    md_write_end(conf->mddev);
					    wbi->bi_next = return_bi;
					    return_bi = wbi;
				    }
				    wbi = wbi2;
			    }
1266 1267
			    if (dev->towrite == NULL)
				    bitmap_end = 1;
L
Linus Torvalds 已提交
1268
			    spin_unlock_irq(&conf->device_lock);
1269 1270 1271 1272
			    if (bitmap_end)
				    bitmap_endwrite(conf->mddev->bitmap, sh->sector,
						    STRIPE_SECTORS,
						    !test_bit(STRIPE_DEGRADED, &sh->state), 0);
L
Linus Torvalds 已提交
1273 1274 1275 1276 1277 1278 1279 1280
		    }
		}
	}

	/* Now we might consider reading some blocks, either to check/generate
	 * parity, or to satisfy requests
	 * or to load a block that is being partially written.
	 */
1281
	if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) {
L
Linus Torvalds 已提交
1282 1283 1284 1285 1286 1287
		for (i=disks; i--;) {
			dev = &sh->dev[i];
			if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
			    (dev->toread ||
			     (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
			     syncing ||
1288
			     expanding ||
L
Linus Torvalds 已提交
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
			     (failed && (sh->dev[failed_num].toread ||
					 (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags))))
				    )
				) {
				/* we would like to get this block, possibly
				 * by computing it, but we might not be able to
				 */
				if (uptodate == disks-1) {
					PRINTK("Computing block %d\n", i);
					compute_block(sh, i);
					uptodate++;
				} else if (test_bit(R5_Insync, &dev->flags)) {
					set_bit(R5_LOCKED, &dev->flags);
					set_bit(R5_Wantread, &dev->flags);
#if 0
					/* if I am just reading this block and we don't have
					   a failed drive, or any pending writes then sidestep the cache */
					if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
					    ! syncing && !failed && !to_write) {
						sh->bh_cache[i]->b_page =  sh->bh_read[i]->b_page;
						sh->bh_cache[i]->b_data =  sh->bh_read[i]->b_data;
					}
#endif
					locked++;
					PRINTK("Reading block %d (sync=%d)\n", 
						i, syncing);
				}
			}
		}
		set_bit(STRIPE_HANDLE, &sh->state);
	}

	/* now to consider writing and what else, if anything should be read */
	if (to_write) {
		int rmw=0, rcw=0;
		for (i=disks ; i--;) {
			/* would I have to read this buffer for read_modify_write */
			dev = &sh->dev[i];
			if ((dev->towrite || i == sh->pd_idx) &&
			    (!test_bit(R5_LOCKED, &dev->flags) 
#if 0
|| sh->bh_page[i]!=bh->b_page
#endif
				    ) &&
			    !test_bit(R5_UPTODATE, &dev->flags)) {
				if (test_bit(R5_Insync, &dev->flags)
/*				    && !(!mddev->insync && i == sh->pd_idx) */
					)
					rmw++;
				else rmw += 2*disks;  /* cannot read it */
			}
			/* Would I have to read this buffer for reconstruct_write */
			if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
			    (!test_bit(R5_LOCKED, &dev->flags) 
#if 0
|| sh->bh_page[i] != bh->b_page
#endif
				    ) &&
			    !test_bit(R5_UPTODATE, &dev->flags)) {
				if (test_bit(R5_Insync, &dev->flags)) rcw++;
				else rcw += 2*disks;
			}
		}
		PRINTK("for sector %llu, rmw=%d rcw=%d\n", 
			(unsigned long long)sh->sector, rmw, rcw);
		set_bit(STRIPE_HANDLE, &sh->state);
		if (rmw < rcw && rmw > 0)
			/* prefer read-modify-write, but need to get some data */
			for (i=disks; i--;) {
				dev = &sh->dev[i];
				if ((dev->towrite || i == sh->pd_idx) &&
				    !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
				    test_bit(R5_Insync, &dev->flags)) {
					if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
					{
						PRINTK("Read_old block %d for r-m-w\n", i);
						set_bit(R5_LOCKED, &dev->flags);
						set_bit(R5_Wantread, &dev->flags);
						locked++;
					} else {
						set_bit(STRIPE_DELAYED, &sh->state);
						set_bit(STRIPE_HANDLE, &sh->state);
					}
				}
			}
		if (rcw <= rmw && rcw > 0)
			/* want reconstruct write, but need to get some data */
			for (i=disks; i--;) {
				dev = &sh->dev[i];
				if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
				    !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
				    test_bit(R5_Insync, &dev->flags)) {
					if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
					{
						PRINTK("Read_old block %d for Reconstruct\n", i);
						set_bit(R5_LOCKED, &dev->flags);
						set_bit(R5_Wantread, &dev->flags);
						locked++;
					} else {
						set_bit(STRIPE_DELAYED, &sh->state);
						set_bit(STRIPE_HANDLE, &sh->state);
					}
				}
			}
		/* now if nothing is locked, and if we have enough data, we can start a write request */
1394 1395
		if (locked == 0 && (rcw == 0 ||rmw == 0) &&
		    !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
L
Linus Torvalds 已提交
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420
			PRINTK("Computing parity...\n");
			compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
			/* now every locked buffer is ready to be written */
			for (i=disks; i--;)
				if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
					PRINTK("Writing block %d\n", i);
					locked++;
					set_bit(R5_Wantwrite, &sh->dev[i].flags);
					if (!test_bit(R5_Insync, &sh->dev[i].flags)
					    || (i==sh->pd_idx && failed == 0))
						set_bit(STRIPE_INSYNC, &sh->state);
				}
			if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
				atomic_dec(&conf->preread_active_stripes);
				if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
					md_wakeup_thread(conf->mddev->thread);
			}
		}
	}

	/* maybe we need to check and possibly fix the parity for this stripe
	 * Any reads will already have been scheduled, so we just see if enough data
	 * is available
	 */
	if (syncing && locked == 0 &&
N
NeilBrown 已提交
1421
	    !test_bit(STRIPE_INSYNC, &sh->state)) {
L
Linus Torvalds 已提交
1422 1423 1424
		set_bit(STRIPE_HANDLE, &sh->state);
		if (failed == 0) {
			char *pagea;
1425
			BUG_ON(uptodate != disks);
L
Linus Torvalds 已提交
1426 1427 1428 1429 1430 1431 1432
			compute_parity(sh, CHECK_PARITY);
			uptodate--;
			pagea = page_address(sh->dev[sh->pd_idx].page);
			if ((*(u32*)pagea) == 0 &&
			    !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {
				/* parity is correct (on disc, not in buffer any more) */
				set_bit(STRIPE_INSYNC, &sh->state);
1433 1434 1435 1436 1437
			} else {
				conf->mddev->resync_mismatches += STRIPE_SECTORS;
				if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
					/* don't try to repair!! */
					set_bit(STRIPE_INSYNC, &sh->state);
N
NeilBrown 已提交
1438 1439 1440 1441
				else {
					compute_block(sh, sh->pd_idx);
					uptodate++;
				}
L
Linus Torvalds 已提交
1442 1443 1444
			}
		}
		if (!test_bit(STRIPE_INSYNC, &sh->state)) {
N
NeilBrown 已提交
1445
			/* either failed parity check, or recovery is happening */
L
Linus Torvalds 已提交
1446 1447 1448
			if (failed==0)
				failed_num = sh->pd_idx;
			dev = &sh->dev[failed_num];
N
NeilBrown 已提交
1449 1450 1451
			BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
			BUG_ON(uptodate != disks);

L
Linus Torvalds 已提交
1452 1453
			set_bit(R5_LOCKED, &dev->flags);
			set_bit(R5_Wantwrite, &dev->flags);
1454
			clear_bit(STRIPE_DEGRADED, &sh->state);
L
Linus Torvalds 已提交
1455 1456 1457 1458 1459 1460 1461 1462
			locked++;
			set_bit(STRIPE_INSYNC, &sh->state);
		}
	}
	if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
		md_done_sync(conf->mddev, STRIPE_SECTORS,1);
		clear_bit(STRIPE_SYNCING, &sh->state);
	}
1463 1464 1465 1466

	/* If the failed drive is just a ReadError, then we might need to progress
	 * the repair/check process
	 */
1467 1468
	if (failed == 1 && ! conf->mddev->ro &&
	    test_bit(R5_ReadError, &sh->dev[failed_num].flags)
1469 1470 1471 1472 1473 1474 1475 1476
	    && !test_bit(R5_LOCKED, &sh->dev[failed_num].flags)
	    && test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)
		) {
		dev = &sh->dev[failed_num];
		if (!test_bit(R5_ReWrite, &dev->flags)) {
			set_bit(R5_Wantwrite, &dev->flags);
			set_bit(R5_ReWrite, &dev->flags);
			set_bit(R5_LOCKED, &dev->flags);
1477
			locked++;
1478 1479 1480 1481
		} else {
			/* let's read it back */
			set_bit(R5_Wantread, &dev->flags);
			set_bit(R5_LOCKED, &dev->flags);
1482
			locked++;
1483 1484 1485
		}
	}

1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
	if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
		/* Need to write out all blocks after computing parity */
		sh->disks = conf->raid_disks;
		sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
		compute_parity(sh, RECONSTRUCT_WRITE);
		for (i= conf->raid_disks; i--;) {
			set_bit(R5_LOCKED, &sh->dev[i].flags);
			locked++;
			set_bit(R5_Wantwrite, &sh->dev[i].flags);
		}
		clear_bit(STRIPE_EXPANDING, &sh->state);
	} else if (expanded) {
		clear_bit(STRIPE_EXPAND_READY, &sh->state);
1499
		atomic_dec(&conf->reshape_stripes);
1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547
		wake_up(&conf->wait_for_overlap);
		md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
	}

	if (expanding && locked == 0) {
		/* We have read all the blocks in this stripe and now we need to
		 * copy some of them into a target stripe for expand.
		 */
		clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
		for (i=0; i< sh->disks; i++)
			if (i != sh->pd_idx) {
				int dd_idx, pd_idx, j;
				struct stripe_head *sh2;

				sector_t bn = compute_blocknr(sh, i);
				sector_t s = raid5_compute_sector(bn, conf->raid_disks,
								  conf->raid_disks-1,
								  &dd_idx, &pd_idx, conf);
				sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1);
				if (sh2 == NULL)
					/* so far only the early blocks of this stripe
					 * have been requested.  When later blocks
					 * get requested, we will try again
					 */
					continue;
				if(!test_bit(STRIPE_EXPANDING, &sh2->state) ||
				   test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
					/* must have already done this block */
					release_stripe(sh2);
					continue;
				}
				memcpy(page_address(sh2->dev[dd_idx].page),
				       page_address(sh->dev[i].page),
				       STRIPE_SIZE);
				set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
				set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
				for (j=0; j<conf->raid_disks; j++)
					if (j != sh2->pd_idx &&
					    !test_bit(R5_Expanded, &sh2->dev[j].flags))
						break;
				if (j == conf->raid_disks) {
					set_bit(STRIPE_EXPAND_READY, &sh2->state);
					set_bit(STRIPE_HANDLE, &sh2->state);
				}
				release_stripe(sh2);
			}
	}

L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577
	spin_unlock(&sh->lock);

	while ((bi=return_bi)) {
		int bytes = bi->bi_size;

		return_bi = bi->bi_next;
		bi->bi_next = NULL;
		bi->bi_size = 0;
		bi->bi_end_io(bi, bytes, 0);
	}
	for (i=disks; i-- ;) {
		int rw;
		struct bio *bi;
		mdk_rdev_t *rdev;
		if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
			rw = 1;
		else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
			rw = 0;
		else
			continue;
 
		bi = &sh->dev[i].req;
 
		bi->bi_rw = rw;
		if (rw)
			bi->bi_end_io = raid5_end_write_request;
		else
			bi->bi_end_io = raid5_end_read_request;
 
		rcu_read_lock();
1578
		rdev = rcu_dereference(conf->disks[i].rdev);
1579
		if (rdev && test_bit(Faulty, &rdev->flags))
L
Linus Torvalds 已提交
1580 1581 1582 1583 1584 1585
			rdev = NULL;
		if (rdev)
			atomic_inc(&rdev->nr_pending);
		rcu_read_unlock();
 
		if (rdev) {
1586
			if (syncing || expanding || expanded)
L
Linus Torvalds 已提交
1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
				md_sync_acct(rdev->bdev, STRIPE_SECTORS);

			bi->bi_bdev = rdev->bdev;
			PRINTK("for %llu schedule op %ld on disc %d\n",
				(unsigned long long)sh->sector, bi->bi_rw, i);
			atomic_inc(&sh->count);
			bi->bi_sector = sh->sector + rdev->data_offset;
			bi->bi_flags = 1 << BIO_UPTODATE;
			bi->bi_vcnt = 1;	
			bi->bi_max_vecs = 1;
			bi->bi_idx = 0;
			bi->bi_io_vec = &sh->dev[i].vec;
			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
			bi->bi_io_vec[0].bv_offset = 0;
			bi->bi_size = STRIPE_SIZE;
			bi->bi_next = NULL;
1603 1604 1605
			if (rw == WRITE &&
			    test_bit(R5_ReWrite, &sh->dev[i].flags))
				atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
L
Linus Torvalds 已提交
1606 1607
			generic_make_request(bi);
		} else {
1608 1609
			if (rw == 1)
				set_bit(STRIPE_DEGRADED, &sh->state);
L
Linus Torvalds 已提交
1610 1611 1612 1613 1614 1615 1616 1617
			PRINTK("skip op %ld on disc %d for sector %llu\n",
				bi->bi_rw, i, (unsigned long long)sh->sector);
			clear_bit(R5_LOCKED, &sh->dev[i].flags);
			set_bit(STRIPE_HANDLE, &sh->state);
		}
	}
}

1618
static void raid5_activate_delayed(raid5_conf_t *conf)
L
Linus Torvalds 已提交
1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633
{
	if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
		while (!list_empty(&conf->delayed_list)) {
			struct list_head *l = conf->delayed_list.next;
			struct stripe_head *sh;
			sh = list_entry(l, struct stripe_head, lru);
			list_del_init(l);
			clear_bit(STRIPE_DELAYED, &sh->state);
			if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
				atomic_inc(&conf->preread_active_stripes);
			list_add_tail(&sh->lru, &conf->handle_list);
		}
	}
}

1634
static void activate_bit_delay(raid5_conf_t *conf)
1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647
{
	/* device_lock is held */
	struct list_head head;
	list_add(&head, &conf->bitmap_list);
	list_del_init(&conf->bitmap_list);
	while (!list_empty(&head)) {
		struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
		list_del_init(&sh->lru);
		atomic_inc(&sh->count);
		__release_stripe(conf, sh);
	}
}

L
Linus Torvalds 已提交
1648 1649 1650 1651 1652 1653 1654
static void unplug_slaves(mddev_t *mddev)
{
	raid5_conf_t *conf = mddev_to_conf(mddev);
	int i;

	rcu_read_lock();
	for (i=0; i<mddev->raid_disks; i++) {
1655
		mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
1656
		if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
L
Linus Torvalds 已提交
1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
			request_queue_t *r_queue = bdev_get_queue(rdev->bdev);

			atomic_inc(&rdev->nr_pending);
			rcu_read_unlock();

			if (r_queue->unplug_fn)
				r_queue->unplug_fn(r_queue);

			rdev_dec_pending(rdev, mddev);
			rcu_read_lock();
		}
	}
	rcu_read_unlock();
}

static void raid5_unplug_device(request_queue_t *q)
{
	mddev_t *mddev = q->queuedata;
	raid5_conf_t *conf = mddev_to_conf(mddev);
	unsigned long flags;

	spin_lock_irqsave(&conf->device_lock, flags);

1680 1681
	if (blk_remove_plug(q)) {
		conf->seq_flush++;
L
Linus Torvalds 已提交
1682
		raid5_activate_delayed(conf);
1683
	}
L
Linus Torvalds 已提交
1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
	md_wakeup_thread(mddev->thread);

	spin_unlock_irqrestore(&conf->device_lock, flags);

	unplug_slaves(mddev);
}

static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk,
			     sector_t *error_sector)
{
	mddev_t *mddev = q->queuedata;
	raid5_conf_t *conf = mddev_to_conf(mddev);
	int i, ret = 0;

	rcu_read_lock();
	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
1700
		mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
1701
		if (rdev && !test_bit(Faulty, &rdev->flags)) {
L
Linus Torvalds 已提交
1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727
			struct block_device *bdev = rdev->bdev;
			request_queue_t *r_queue = bdev_get_queue(bdev);

			if (!r_queue->issue_flush_fn)
				ret = -EOPNOTSUPP;
			else {
				atomic_inc(&rdev->nr_pending);
				rcu_read_unlock();
				ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
							      error_sector);
				rdev_dec_pending(rdev, mddev);
				rcu_read_lock();
			}
		}
	}
	rcu_read_unlock();
	return ret;
}

static inline void raid5_plug_device(raid5_conf_t *conf)
{
	spin_lock_irq(&conf->device_lock);
	blk_plug_device(conf->mddev->queue);
	spin_unlock_irq(&conf->device_lock);
}

1728
static int make_request(request_queue_t *q, struct bio * bi)
L
Linus Torvalds 已提交
1729 1730 1731 1732 1733 1734 1735
{
	mddev_t *mddev = q->queuedata;
	raid5_conf_t *conf = mddev_to_conf(mddev);
	unsigned int dd_idx, pd_idx;
	sector_t new_sector;
	sector_t logical_sector, last_sector;
	struct stripe_head *sh;
1736
	const int rw = bio_data_dir(bi);
1737
	int remaining;
L
Linus Torvalds 已提交
1738

1739 1740 1741 1742 1743
	if (unlikely(bio_barrier(bi))) {
		bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
		return 0;
	}

1744
	md_write_start(mddev, bi);
1745

1746 1747
	disk_stat_inc(mddev->gendisk, ios[rw]);
	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
L
Linus Torvalds 已提交
1748 1749 1750 1751 1752

	logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
	last_sector = bi->bi_sector + (bi->bi_size>>9);
	bi->bi_next = NULL;
	bi->bi_phys_segments = 1;	/* over-loaded to count active stripes */
1753

L
Linus Torvalds 已提交
1754 1755
	for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
		DEFINE_WAIT(w);
1756
		int disks;
1757

1758
	retry:
1759
		prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
1760 1761 1762
		if (likely(conf->expand_progress == MaxSector))
			disks = conf->raid_disks;
		else {
1763 1764 1765 1766 1767 1768 1769 1770
			/* spinlock is needed as expand_progress may be
			 * 64bit on a 32bit platform, and so it might be
			 * possible to see a half-updated value
			 * Ofcourse expand_progress could change after
			 * the lock is dropped, so once we get a reference
			 * to the stripe that we think it is, we will have
			 * to check again.
			 */
1771 1772 1773 1774
			spin_lock_irq(&conf->device_lock);
			disks = conf->raid_disks;
			if (logical_sector >= conf->expand_progress)
				disks = conf->previous_raid_disks;
1775 1776 1777 1778 1779 1780 1781
			else {
				if (logical_sector >= conf->expand_lo) {
					spin_unlock_irq(&conf->device_lock);
					schedule();
					goto retry;
				}
			}
1782 1783 1784 1785
			spin_unlock_irq(&conf->device_lock);
		}
 		new_sector = raid5_compute_sector(logical_sector, disks, disks - 1,
						  &dd_idx, &pd_idx, conf);
L
Linus Torvalds 已提交
1786 1787 1788 1789
		PRINTK("raid5: make_request, sector %llu logical %llu\n",
			(unsigned long long)new_sector, 
			(unsigned long long)logical_sector);

1790
		sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
L
Linus Torvalds 已提交
1791
		if (sh) {
1792 1793
			if (unlikely(conf->expand_progress != MaxSector)) {
				/* expansion might have moved on while waiting for a
1794 1795 1796 1797 1798 1799
				 * stripe, so we must do the range check again.
				 * Expansion could still move past after this
				 * test, but as we are holding a reference to
				 * 'sh', we know that if that happens,
				 *  STRIPE_EXPANDING will get set and the expansion
				 * won't proceed until we finish with the stripe.
1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
				 */
				int must_retry = 0;
				spin_lock_irq(&conf->device_lock);
				if (logical_sector <  conf->expand_progress &&
				    disks == conf->previous_raid_disks)
					/* mismatch, need to try again */
					must_retry = 1;
				spin_unlock_irq(&conf->device_lock);
				if (must_retry) {
					release_stripe(sh);
					goto retry;
				}
			}
1813 1814 1815 1816 1817 1818 1819 1820 1821
			/* FIXME what if we get a false positive because these
			 * are being updated.
			 */
			if (logical_sector >= mddev->suspend_lo &&
			    logical_sector < mddev->suspend_hi) {
				release_stripe(sh);
				schedule();
				goto retry;
			}
1822 1823 1824 1825 1826

			if (test_bit(STRIPE_EXPANDING, &sh->state) ||
			    !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
				/* Stripe is busy expanding or
				 * add failed due to overlap.  Flush everything
L
Linus Torvalds 已提交
1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
				 * and wait a while
				 */
				raid5_unplug_device(mddev->queue);
				release_stripe(sh);
				schedule();
				goto retry;
			}
			finish_wait(&conf->wait_for_overlap, &w);
			raid5_plug_device(conf);
			handle_stripe(sh);
			release_stripe(sh);
		} else {
			/* cannot get stripe for read-ahead, just give-up */
			clear_bit(BIO_UPTODATE, &bi->bi_flags);
			finish_wait(&conf->wait_for_overlap, &w);
			break;
		}
			
	}
	spin_lock_irq(&conf->device_lock);
1847 1848 1849
	remaining = --bi->bi_phys_segments;
	spin_unlock_irq(&conf->device_lock);
	if (remaining == 0) {
L
Linus Torvalds 已提交
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860
		int bytes = bi->bi_size;

		if ( bio_data_dir(bi) == WRITE )
			md_write_end(mddev);
		bi->bi_size = 0;
		bi->bi_end_io(bi, bytes, 0);
	}
	return 0;
}

/* FIXME go_faster isn't used */
1861
static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
L
Linus Torvalds 已提交
1862 1863 1864
{
	raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
	struct stripe_head *sh;
1865 1866
	int pd_idx;
	sector_t first_sector, last_sector;
L
Linus Torvalds 已提交
1867 1868
	int raid_disks = conf->raid_disks;
	int data_disks = raid_disks-1;
1869 1870
	sector_t max_sector = mddev->size << 1;
	int sync_blocks;
L
Linus Torvalds 已提交
1871

1872
	if (sector_nr >= max_sector) {
L
Linus Torvalds 已提交
1873 1874
		/* just being told to finish up .. nothing much to do */
		unplug_slaves(mddev);
1875 1876 1877 1878
		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
			end_reshape(conf);
			return 0;
		}
1879 1880 1881 1882 1883 1884 1885 1886

		if (mddev->curr_resync < max_sector) /* aborted */
			bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
					&sync_blocks, 1);
		else /* compelted sync */
			conf->fullsync = 0;
		bitmap_close_sync(mddev->bitmap);

L
Linus Torvalds 已提交
1887 1888
		return 0;
	}
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901

	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
		/* reshaping is quite different to recovery/resync so it is
		 * handled quite separately ... here.
		 *
		 * On each call to sync_request, we gather one chunk worth of
		 * destination stripes and flag them as expanding.
		 * Then we find all the source stripes and request reads.
		 * As the reads complete, handle_stripe will copy the data
		 * into the destination stripe and release that stripe.
		 */
		int i;
		int dd_idx;
1902
		sector_t writepos, safepos, gap;
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912

		if (sector_nr == 0 &&
		    conf->expand_progress != 0) {
			/* restarting in the middle, skip the initial sectors */
			sector_nr = conf->expand_progress;
			sector_div(sector_nr, conf->raid_disks-1);
			*skipped = 1;
			return sector_nr;
		}

1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942
		/* we update the metadata when there is more than 3Meg
		 * in the block range (that is rather arbitrary, should
		 * probably be time based) or when the data about to be
		 * copied would over-write the source of the data at
		 * the front of the range.
		 * i.e. one new_stripe forward from expand_progress new_maps
		 * to after where expand_lo old_maps to
		 */
		writepos = conf->expand_progress +
			conf->chunk_size/512*(conf->raid_disks-1);
		sector_div(writepos, conf->raid_disks-1);
		safepos = conf->expand_lo;
		sector_div(safepos, conf->previous_raid_disks-1);
		gap = conf->expand_progress - conf->expand_lo;

		if (writepos >= safepos ||
		    gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) {
			/* Cannot proceed until we've updated the superblock... */
			wait_event(conf->wait_for_overlap,
				   atomic_read(&conf->reshape_stripes)==0);
			mddev->reshape_position = conf->expand_progress;
			mddev->sb_dirty = 1;
			md_wakeup_thread(mddev->thread);
			wait_event(mddev->sb_wait, mddev->sb_dirty == 0 ||
				   kthread_should_stop());
			spin_lock_irq(&conf->device_lock);
			conf->expand_lo = mddev->reshape_position;
			spin_unlock_irq(&conf->device_lock);
			wake_up(&conf->wait_for_overlap);
		}
1943

1944 1945 1946 1947 1948 1949 1950
		for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
			int j;
			int skipped = 0;
			pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
			sh = get_active_stripe(conf, sector_nr+i,
					       conf->raid_disks, pd_idx, 0);
			set_bit(STRIPE_EXPANDING, &sh->state);
1951
			atomic_inc(&conf->reshape_stripes);
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
			/* If any of this stripe is beyond the end of the old
			 * array, then we need to zero those blocks
			 */
			for (j=sh->disks; j--;) {
				sector_t s;
				if (j == sh->pd_idx)
					continue;
				s = compute_blocknr(sh, j);
				if (s < (mddev->array_size<<1)) {
					skipped = 1;
					continue;
				}
				memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
				set_bit(R5_Expanded, &sh->dev[j].flags);
				set_bit(R5_UPTODATE, &sh->dev[j].flags);
			}
			if (!skipped) {
				set_bit(STRIPE_EXPAND_READY, &sh->state);
				set_bit(STRIPE_HANDLE, &sh->state);
			}
			release_stripe(sh);
		}
		spin_lock_irq(&conf->device_lock);
		conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1);
		spin_unlock_irq(&conf->device_lock);
		/* Ok, those stripe are ready. We can start scheduling
		 * reads on the source stripes.
		 * The source stripes are determined by mapping the first and last
		 * block on the destination stripes.
		 */
		raid_disks = conf->previous_raid_disks;
		data_disks = raid_disks - 1;
		first_sector =
			raid5_compute_sector(sector_nr*(conf->raid_disks-1),
					     raid_disks, data_disks,
					     &dd_idx, &pd_idx, conf);
		last_sector =
			raid5_compute_sector((sector_nr+conf->chunk_size/512)
					       *(conf->raid_disks-1) -1,
					     raid_disks, data_disks,
					     &dd_idx, &pd_idx, conf);
		if (last_sector >= (mddev->size<<1))
			last_sector = (mddev->size<<1)-1;
		while (first_sector <= last_sector) {
			pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks);
			sh = get_active_stripe(conf, first_sector,
					       conf->previous_raid_disks, pd_idx, 0);
			set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
			set_bit(STRIPE_HANDLE, &sh->state);
			release_stripe(sh);
			first_sector += STRIPE_SECTORS;
		}
		return conf->chunk_size>>9;
	}
L
Linus Torvalds 已提交
2006 2007 2008 2009 2010
	/* if there is 1 or more failed drives and we are trying
	 * to resync, then assert that we are finished, because there is
	 * nothing we can do.
	 */
	if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2011 2012
		sector_t rv = (mddev->size << 1) - sector_nr;
		*skipped = 1;
L
Linus Torvalds 已提交
2013 2014
		return rv;
	}
2015
	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2016
	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2017 2018 2019 2020 2021 2022
	    !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
		/* we can skip this block, and probably more */
		sync_blocks /= STRIPE_SECTORS;
		*skipped = 1;
		return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
	}
L
Linus Torvalds 已提交
2023

2024
	pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
2025
	sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
L
Linus Torvalds 已提交
2026
	if (sh == NULL) {
2027
		sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
L
Linus Torvalds 已提交
2028 2029 2030
		/* make sure we don't swamp the stripe cache if someone else
		 * is trying to get access 
		 */
2031
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
2032
	}
2033
	bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0);
L
Linus Torvalds 已提交
2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066
	spin_lock(&sh->lock);	
	set_bit(STRIPE_SYNCING, &sh->state);
	clear_bit(STRIPE_INSYNC, &sh->state);
	spin_unlock(&sh->lock);

	handle_stripe(sh);
	release_stripe(sh);

	return STRIPE_SECTORS;
}

/*
 * This is our raid5 kernel thread.
 *
 * We scan the hash table for stripes which can be handled now.
 * During the scan, completed stripes are saved for us by the interrupt
 * handler, so that they will not have to wait for our next wakeup.
 */
static void raid5d (mddev_t *mddev)
{
	struct stripe_head *sh;
	raid5_conf_t *conf = mddev_to_conf(mddev);
	int handled;

	PRINTK("+++ raid5d active\n");

	md_check_recovery(mddev);

	handled = 0;
	spin_lock_irq(&conf->device_lock);
	while (1) {
		struct list_head *first;

2067 2068
		if (conf->seq_flush - conf->seq_write > 0) {
			int seq = conf->seq_flush;
2069
			spin_unlock_irq(&conf->device_lock);
2070
			bitmap_unplug(mddev->bitmap);
2071
			spin_lock_irq(&conf->device_lock);
2072 2073 2074 2075
			conf->seq_write = seq;
			activate_bit_delay(conf);
		}

L
Linus Torvalds 已提交
2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089
		if (list_empty(&conf->handle_list) &&
		    atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD &&
		    !blk_queue_plugged(mddev->queue) &&
		    !list_empty(&conf->delayed_list))
			raid5_activate_delayed(conf);

		if (list_empty(&conf->handle_list))
			break;

		first = conf->handle_list.next;
		sh = list_entry(first, struct stripe_head, lru);

		list_del_init(first);
		atomic_inc(&sh->count);
2090
		BUG_ON(atomic_read(&sh->count)!= 1);
L
Linus Torvalds 已提交
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107
		spin_unlock_irq(&conf->device_lock);
		
		handled++;
		handle_stripe(sh);
		release_stripe(sh);

		spin_lock_irq(&conf->device_lock);
	}
	PRINTK("%d stripes handled\n", handled);

	spin_unlock_irq(&conf->device_lock);

	unplug_slaves(mddev);

	PRINTK("--- raid5d inactive\n");
}

2108
static ssize_t
2109
raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
2110
{
2111
	raid5_conf_t *conf = mddev_to_conf(mddev);
2112 2113 2114 2115
	if (conf)
		return sprintf(page, "%d\n", conf->max_nr_stripes);
	else
		return 0;
2116 2117 2118
}

static ssize_t
2119
raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
2120
{
2121
	raid5_conf_t *conf = mddev_to_conf(mddev);
2122 2123 2124 2125
	char *end;
	int new;
	if (len >= PAGE_SIZE)
		return -EINVAL;
2126 2127
	if (!conf)
		return -ENODEV;
2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146

	new = simple_strtoul(page, &end, 10);
	if (!*page || (*end && *end != '\n') )
		return -EINVAL;
	if (new <= 16 || new > 32768)
		return -EINVAL;
	while (new < conf->max_nr_stripes) {
		if (drop_one_stripe(conf))
			conf->max_nr_stripes--;
		else
			break;
	}
	while (new > conf->max_nr_stripes) {
		if (grow_one_stripe(conf))
			conf->max_nr_stripes++;
		else break;
	}
	return len;
}
2147

2148 2149 2150 2151
static struct md_sysfs_entry
raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
				raid5_show_stripe_cache_size,
				raid5_store_stripe_cache_size);
2152 2153

static ssize_t
2154
stripe_cache_active_show(mddev_t *mddev, char *page)
2155
{
2156
	raid5_conf_t *conf = mddev_to_conf(mddev);
2157 2158 2159 2160
	if (conf)
		return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
	else
		return 0;
2161 2162
}

2163 2164
static struct md_sysfs_entry
raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
2165

2166
static struct attribute *raid5_attrs[] =  {
2167 2168 2169 2170
	&raid5_stripecache_size.attr,
	&raid5_stripecache_active.attr,
	NULL,
};
2171 2172 2173
static struct attribute_group raid5_attrs_group = {
	.name = NULL,
	.attrs = raid5_attrs,
2174 2175
};

2176
static int run(mddev_t *mddev)
L
Linus Torvalds 已提交
2177 2178 2179 2180 2181 2182 2183 2184
{
	raid5_conf_t *conf;
	int raid_disk, memory;
	mdk_rdev_t *rdev;
	struct disk_info *disk;
	struct list_head *tmp;

	if (mddev->level != 5 && mddev->level != 4) {
N
NeilBrown 已提交
2185 2186
		printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n",
		       mdname(mddev), mddev->level);
L
Linus Torvalds 已提交
2187 2188 2189
		return -EIO;
	}

2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
	if (mddev->reshape_position != MaxSector) {
		/* Check that we can continue the reshape.
		 * Currently only disks can change, it must
		 * increase, and we must be past the point where
		 * a stripe over-writes itself
		 */
		sector_t here_new, here_old;
		int old_disks;

		if (mddev->new_level != mddev->level ||
		    mddev->new_layout != mddev->layout ||
		    mddev->new_chunk != mddev->chunk_size) {
			printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n",
			       mdname(mddev));
			return -EINVAL;
		}
		if (mddev->delta_disks <= 0) {
			printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n",
			       mdname(mddev));
			return -EINVAL;
		}
		old_disks = mddev->raid_disks - mddev->delta_disks;
		/* reshape_position must be on a new-stripe boundary, and one
		 * further up in new geometry must map after here in old geometry.
		 */
		here_new = mddev->reshape_position;
		if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) {
			printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n");
			return -EINVAL;
		}
		/* here_new is the stripe we will write to */
		here_old = mddev->reshape_position;
		sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1));
		/* here_old is the first stripe that we might need to read from */
		if (here_new >= here_old) {
			/* Reading from the same stripe as writing to - bad */
			printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n");
			return -EINVAL;
		}
		printk(KERN_INFO "raid5: reshape will continue\n");
		/* OK, we should be able to continue; */
	}


2234
	mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
L
Linus Torvalds 已提交
2235 2236
	if ((conf = mddev->private) == NULL)
		goto abort;
2237 2238 2239 2240 2241 2242 2243 2244
	if (mddev->reshape_position == MaxSector) {
		conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
	} else {
		conf->raid_disks = mddev->raid_disks;
		conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
	}

	conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
2245 2246 2247
			      GFP_KERNEL);
	if (!conf->disks)
		goto abort;
2248

L
Linus Torvalds 已提交
2249 2250
	conf->mddev = mddev;

2251
	if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
L
Linus Torvalds 已提交
2252 2253 2254 2255 2256 2257 2258
		goto abort;

	spin_lock_init(&conf->device_lock);
	init_waitqueue_head(&conf->wait_for_stripe);
	init_waitqueue_head(&conf->wait_for_overlap);
	INIT_LIST_HEAD(&conf->handle_list);
	INIT_LIST_HEAD(&conf->delayed_list);
2259
	INIT_LIST_HEAD(&conf->bitmap_list);
L
Linus Torvalds 已提交
2260 2261 2262 2263 2264 2265 2266 2267
	INIT_LIST_HEAD(&conf->inactive_list);
	atomic_set(&conf->active_stripes, 0);
	atomic_set(&conf->preread_active_stripes, 0);

	PRINTK("raid5: run(%s) called.\n", mdname(mddev));

	ITERATE_RDEV(mddev,rdev,tmp) {
		raid_disk = rdev->raid_disk;
2268
		if (raid_disk >= conf->raid_disks
L
Linus Torvalds 已提交
2269 2270 2271 2272 2273 2274
		    || raid_disk < 0)
			continue;
		disk = conf->disks + raid_disk;

		disk->rdev = rdev;

2275
		if (test_bit(In_sync, &rdev->flags)) {
L
Linus Torvalds 已提交
2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292
			char b[BDEVNAME_SIZE];
			printk(KERN_INFO "raid5: device %s operational as raid"
				" disk %d\n", bdevname(rdev->bdev,b),
				raid_disk);
			conf->working_disks++;
		}
	}

	/*
	 * 0 for a fully functional array, 1 for a degraded array.
	 */
	mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks;
	conf->mddev = mddev;
	conf->chunk_size = mddev->chunk_size;
	conf->level = mddev->level;
	conf->algorithm = mddev->layout;
	conf->max_nr_stripes = NR_STRIPES;
2293
	conf->expand_progress = mddev->reshape_position;
L
Linus Torvalds 已提交
2294 2295 2296

	/* device size must be a multiple of chunk size */
	mddev->size &= ~(mddev->chunk_size/1024 -1);
2297
	mddev->resync_max_sectors = mddev->size << 1;
L
Linus Torvalds 已提交
2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318

	if (!conf->chunk_size || conf->chunk_size % 4) {
		printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
			conf->chunk_size, mdname(mddev));
		goto abort;
	}
	if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
		printk(KERN_ERR 
			"raid5: unsupported parity algorithm %d for %s\n",
			conf->algorithm, mdname(mddev));
		goto abort;
	}
	if (mddev->degraded > 1) {
		printk(KERN_ERR "raid5: not enough operational devices for %s"
			" (%d/%d failed)\n",
			mdname(mddev), conf->failed_disks, conf->raid_disks);
		goto abort;
	}

	if (mddev->degraded == 1 &&
	    mddev->recovery_cp != MaxSector) {
2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329
		if (mddev->ok_start_degraded)
			printk(KERN_WARNING
			       "raid5: starting dirty degraded array: %s"
			       "- data corruption possible.\n",
			       mdname(mddev));
		else {
			printk(KERN_ERR
			       "raid5: cannot start dirty degraded array for %s\n",
			       mdname(mddev));
			goto abort;
		}
L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340
	}

	{
		mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
		if (!mddev->thread) {
			printk(KERN_ERR 
				"raid5: couldn't allocate thread for %s\n",
				mdname(mddev));
			goto abort;
		}
	}
2341
	memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
L
Linus Torvalds 已提交
2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365
		 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
	if (grow_stripes(conf, conf->max_nr_stripes)) {
		printk(KERN_ERR 
			"raid5: couldn't allocate %dkB for buffers\n", memory);
		shrink_stripes(conf);
		md_unregister_thread(mddev->thread);
		goto abort;
	} else
		printk(KERN_INFO "raid5: allocated %dkB for %s\n",
			memory, mdname(mddev));

	if (mddev->degraded == 0)
		printk("raid5: raid level %d set %s active with %d out of %d"
			" devices, algorithm %d\n", conf->level, mdname(mddev), 
			mddev->raid_disks-mddev->degraded, mddev->raid_disks,
			conf->algorithm);
	else
		printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
			" out of %d devices, algorithm %d\n", conf->level,
			mdname(mddev), mddev->raid_disks - mddev->degraded,
			mddev->raid_disks, conf->algorithm);

	print_raid5_conf(conf);

2366 2367
	if (conf->expand_progress != MaxSector) {
		printk("...ok start reshape thread\n");
2368
		conf->expand_lo = conf->expand_progress;
2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380
		atomic_set(&conf->reshape_stripes, 0);
		clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
		clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
		set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
		mddev->sync_thread = md_register_thread(md_do_sync, mddev,
							"%s_reshape");
		/* FIXME if md_register_thread fails?? */
		md_wakeup_thread(mddev->sync_thread);

	}

L
Linus Torvalds 已提交
2381 2382 2383 2384 2385
	/* read-ahead size must cover two whole stripes, which is
	 * 2 * (n-1) * chunksize where 'n' is the number of raid devices
	 */
	{
		int stripe = (mddev->raid_disks-1) * mddev->chunk_size
2386
			/ PAGE_SIZE;
L
Linus Torvalds 已提交
2387 2388 2389 2390 2391
		if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
			mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
	}

	/* Ok, everything is just fine now */
2392
	sysfs_create_group(&mddev->kobj, &raid5_attrs_group);
2393 2394 2395

	mddev->queue->unplug_fn = raid5_unplug_device;
	mddev->queue->issue_flush_fn = raid5_issue_flush;
2396
	mddev->array_size =  mddev->size * (conf->previous_raid_disks - 1);
2397

L
Linus Torvalds 已提交
2398 2399 2400 2401
	return 0;
abort:
	if (conf) {
		print_raid5_conf(conf);
2402
		kfree(conf->disks);
2403
		kfree(conf->stripe_hashtbl);
L
Linus Torvalds 已提交
2404 2405 2406 2407 2408 2409 2410 2411 2412
		kfree(conf);
	}
	mddev->private = NULL;
	printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
	return -EIO;
}



2413
static int stop(mddev_t *mddev)
L
Linus Torvalds 已提交
2414 2415 2416 2417 2418 2419
{
	raid5_conf_t *conf = (raid5_conf_t *) mddev->private;

	md_unregister_thread(mddev->thread);
	mddev->thread = NULL;
	shrink_stripes(conf);
2420
	kfree(conf->stripe_hashtbl);
L
Linus Torvalds 已提交
2421
	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2422
	sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
2423
	kfree(conf->disks);
2424
	kfree(conf);
L
Linus Torvalds 已提交
2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
	mddev->private = NULL;
	return 0;
}

#if RAID5_DEBUG
static void print_sh (struct stripe_head *sh)
{
	int i;

	printk("sh %llu, pd_idx %d, state %ld.\n",
		(unsigned long long)sh->sector, sh->pd_idx, sh->state);
	printk("sh %llu,  count %d.\n",
		(unsigned long long)sh->sector, atomic_read(&sh->count));
	printk("sh %llu, ", (unsigned long long)sh->sector);
2439
	for (i = 0; i < sh->disks; i++) {
L
Linus Torvalds 已提交
2440 2441 2442 2443 2444 2445 2446 2447 2448
		printk("(cache%d: %p %ld) ", 
			i, sh->dev[i].page, sh->dev[i].flags);
	}
	printk("\n");
}

static void printall (raid5_conf_t *conf)
{
	struct stripe_head *sh;
2449
	struct hlist_node *hn;
L
Linus Torvalds 已提交
2450 2451 2452 2453
	int i;

	spin_lock_irq(&conf->device_lock);
	for (i = 0; i < NR_HASH; i++) {
2454
		hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
L
Linus Torvalds 已提交
2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
			if (sh->raid_conf != conf)
				continue;
			print_sh(sh);
		}
	}
	spin_unlock_irq(&conf->device_lock);
}
#endif

static void status (struct seq_file *seq, mddev_t *mddev)
{
	raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
	int i;

	seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
	seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks);
	for (i = 0; i < conf->raid_disks; i++)
		seq_printf (seq, "%s",
			       conf->disks[i].rdev &&
2474
			       test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
L
Linus Torvalds 已提交
2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500
	seq_printf (seq, "]");
#if RAID5_DEBUG
#define D(x) \
	seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x))
	printall(conf);
#endif
}

static void print_raid5_conf (raid5_conf_t *conf)
{
	int i;
	struct disk_info *tmp;

	printk("RAID5 conf printout:\n");
	if (!conf) {
		printk("(conf==NULL)\n");
		return;
	}
	printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks,
		 conf->working_disks, conf->failed_disks);

	for (i = 0; i < conf->raid_disks; i++) {
		char b[BDEVNAME_SIZE];
		tmp = conf->disks + i;
		if (tmp->rdev)
		printk(" disk %d, o:%d, dev:%s\n",
2501
			i, !test_bit(Faulty, &tmp->rdev->flags),
L
Linus Torvalds 已提交
2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514
			bdevname(tmp->rdev->bdev,b));
	}
}

static int raid5_spare_active(mddev_t *mddev)
{
	int i;
	raid5_conf_t *conf = mddev->private;
	struct disk_info *tmp;

	for (i = 0; i < conf->raid_disks; i++) {
		tmp = conf->disks + i;
		if (tmp->rdev
2515 2516
		    && !test_bit(Faulty, &tmp->rdev->flags)
		    && !test_bit(In_sync, &tmp->rdev->flags)) {
L
Linus Torvalds 已提交
2517 2518 2519
			mddev->degraded--;
			conf->failed_disks--;
			conf->working_disks++;
2520
			set_bit(In_sync, &tmp->rdev->flags);
L
Linus Torvalds 已提交
2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536
		}
	}
	print_raid5_conf(conf);
	return 0;
}

static int raid5_remove_disk(mddev_t *mddev, int number)
{
	raid5_conf_t *conf = mddev->private;
	int err = 0;
	mdk_rdev_t *rdev;
	struct disk_info *p = conf->disks + number;

	print_raid5_conf(conf);
	rdev = p->rdev;
	if (rdev) {
2537
		if (test_bit(In_sync, &rdev->flags) ||
L
Linus Torvalds 已提交
2538 2539 2540 2541 2542
		    atomic_read(&rdev->nr_pending)) {
			err = -EBUSY;
			goto abort;
		}
		p->rdev = NULL;
2543
		synchronize_rcu();
L
Linus Torvalds 已提交
2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569
		if (atomic_read(&rdev->nr_pending)) {
			/* lost the race, try later */
			err = -EBUSY;
			p->rdev = rdev;
		}
	}
abort:

	print_raid5_conf(conf);
	return err;
}

static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
{
	raid5_conf_t *conf = mddev->private;
	int found = 0;
	int disk;
	struct disk_info *p;

	if (mddev->degraded > 1)
		/* no point adding a device */
		return 0;

	/*
	 * find the disk ...
	 */
2570
	for (disk=0; disk < conf->raid_disks; disk++)
L
Linus Torvalds 已提交
2571
		if ((p=conf->disks + disk)->rdev == NULL) {
2572
			clear_bit(In_sync, &rdev->flags);
L
Linus Torvalds 已提交
2573 2574
			rdev->raid_disk = disk;
			found = 1;
2575 2576
			if (rdev->saved_raid_disk != disk)
				conf->fullsync = 1;
2577
			rcu_assign_pointer(p->rdev, rdev);
L
Linus Torvalds 已提交
2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601
			break;
		}
	print_raid5_conf(conf);
	return found;
}

static int raid5_resize(mddev_t *mddev, sector_t sectors)
{
	/* no resync is happening, and there is enough space
	 * on all devices, so we can resize.
	 * We need to make sure resync covers any new space.
	 * If the array is shrinking we should possibly wait until
	 * any io in the removed space completes, but it hardly seems
	 * worth it.
	 */
	sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
	mddev->array_size = (sectors * (mddev->raid_disks-1))>>1;
	set_capacity(mddev->gendisk, mddev->array_size << 1);
	mddev->changed = 1;
	if (sectors/2  > mddev->size && mddev->recovery_cp == MaxSector) {
		mddev->recovery_cp = mddev->size << 1;
		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	}
	mddev->size = sectors /2;
2602
	mddev->resync_max_sectors = sectors;
L
Linus Torvalds 已提交
2603 2604 2605
	return 0;
}

2606
#ifdef CONFIG_MD_RAID5_RESHAPE
2607
static int raid5_check_reshape(mddev_t *mddev)
2608 2609 2610 2611
{
	raid5_conf_t *conf = mddev_to_conf(mddev);
	int err;

2612 2613 2614 2615
	if (mddev->delta_disks < 0 ||
	    mddev->new_level != mddev->level)
		return -EINVAL; /* Cannot shrink array or change level yet */
	if (mddev->delta_disks == 0)
2616 2617 2618 2619 2620 2621 2622 2623 2624 2625
		return 0; /* nothing to do */

	/* Can only proceed if there are plenty of stripe_heads.
	 * We need a minimum of one full stripe,, and for sensible progress
	 * it is best to have about 4 times that.
	 * If we require 4 times, then the default 256 4K stripe_heads will
	 * allow for chunk sizes up to 256K, which is probably OK.
	 * If the chunk size is greater, user-space should request more
	 * stripe_heads first.
	 */
2626 2627
	if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
	    (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
2628 2629 2630 2631 2632
		printk(KERN_WARNING "raid5: reshape: not enough stripes.  Needed %lu\n",
		       (mddev->chunk_size / STRIPE_SIZE)*4);
		return -ENOSPC;
	}

2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652
	err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
	if (err)
		return err;

	/* looks like we might be able to manage this */
	return 0;
}

static int raid5_start_reshape(mddev_t *mddev)
{
	raid5_conf_t *conf = mddev_to_conf(mddev);
	mdk_rdev_t *rdev;
	struct list_head *rtmp;
	int spares = 0;
	int added_devices = 0;

	if (mddev->degraded ||
	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
		return -EBUSY;

2653 2654 2655 2656
	ITERATE_RDEV(mddev, rdev, rtmp)
		if (rdev->raid_disk < 0 &&
		    !test_bit(Faulty, &rdev->flags))
			spares++;
2657 2658

	if (spares < mddev->delta_disks-1)
2659 2660 2661 2662 2663
		/* Not enough devices even to make a degraded array
		 * of that size
		 */
		return -EINVAL;

2664
	atomic_set(&conf->reshape_stripes, 0);
2665 2666
	spin_lock_irq(&conf->device_lock);
	conf->previous_raid_disks = conf->raid_disks;
2667
	conf->raid_disks += mddev->delta_disks;
2668
	conf->expand_progress = 0;
2669
	conf->expand_lo = 0;
2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688
	spin_unlock_irq(&conf->device_lock);

	/* Add some new drives, as many as will fit.
	 * We know there are enough to make the newly sized array work.
	 */
	ITERATE_RDEV(mddev, rdev, rtmp)
		if (rdev->raid_disk < 0 &&
		    !test_bit(Faulty, &rdev->flags)) {
			if (raid5_add_disk(mddev, rdev)) {
				char nm[20];
				set_bit(In_sync, &rdev->flags);
				conf->working_disks++;
				added_devices++;
				sprintf(nm, "rd%d", rdev->raid_disk);
				sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
			} else
				break;
		}

2689 2690
	mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
	mddev->raid_disks = conf->raid_disks;
2691 2692 2693
	mddev->reshape_position = 0;
	mddev->sb_dirty = 1;

2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717
	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
	set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
	set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
	mddev->sync_thread = md_register_thread(md_do_sync, mddev,
						"%s_reshape");
	if (!mddev->sync_thread) {
		mddev->recovery = 0;
		spin_lock_irq(&conf->device_lock);
		mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
		conf->expand_progress = MaxSector;
		spin_unlock_irq(&conf->device_lock);
		return -EAGAIN;
	}
	md_wakeup_thread(mddev->sync_thread);
	md_new_event(mddev);
	return 0;
}
#endif

static void end_reshape(raid5_conf_t *conf)
{
	struct block_device *bdev;

2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733
	if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
		conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1);
		set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
		conf->mddev->changed = 1;

		bdev = bdget_disk(conf->mddev->gendisk, 0);
		if (bdev) {
			mutex_lock(&bdev->bd_inode->i_mutex);
			i_size_write(bdev->bd_inode, conf->mddev->array_size << 10);
			mutex_unlock(&bdev->bd_inode->i_mutex);
			bdput(bdev);
		}
		spin_lock_irq(&conf->device_lock);
		conf->expand_progress = MaxSector;
		spin_unlock_irq(&conf->device_lock);
		conf->mddev->reshape_position = MaxSector;
2734 2735 2736
	}
}

2737 2738 2739 2740 2741
static void raid5_quiesce(mddev_t *mddev, int state)
{
	raid5_conf_t *conf = mddev_to_conf(mddev);

	switch(state) {
2742 2743 2744 2745
	case 2: /* resume for a suspend */
		wake_up(&conf->wait_for_overlap);
		break;

2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758
	case 1: /* stop all writes */
		spin_lock_irq(&conf->device_lock);
		conf->quiesce = 1;
		wait_event_lock_irq(conf->wait_for_stripe,
				    atomic_read(&conf->active_stripes) == 0,
				    conf->device_lock, /* nothing */);
		spin_unlock_irq(&conf->device_lock);
		break;

	case 0: /* re-enable writes */
		spin_lock_irq(&conf->device_lock);
		conf->quiesce = 0;
		wake_up(&conf->wait_for_stripe);
2759
		wake_up(&conf->wait_for_overlap);
2760 2761 2762 2763
		spin_unlock_irq(&conf->device_lock);
		break;
	}
}
2764

2765
static struct mdk_personality raid5_personality =
L
Linus Torvalds 已提交
2766 2767
{
	.name		= "raid5",
2768
	.level		= 5,
L
Linus Torvalds 已提交
2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
	.owner		= THIS_MODULE,
	.make_request	= make_request,
	.run		= run,
	.stop		= stop,
	.status		= status,
	.error_handler	= error,
	.hot_add_disk	= raid5_add_disk,
	.hot_remove_disk= raid5_remove_disk,
	.spare_active	= raid5_spare_active,
	.sync_request	= sync_request,
	.resize		= raid5_resize,
2780
#ifdef CONFIG_MD_RAID5_RESHAPE
2781 2782
	.check_reshape	= raid5_check_reshape,
	.start_reshape  = raid5_start_reshape,
2783
#endif
2784
	.quiesce	= raid5_quiesce,
L
Linus Torvalds 已提交
2785 2786
};

2787
static struct mdk_personality raid4_personality =
L
Linus Torvalds 已提交
2788
{
2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809
	.name		= "raid4",
	.level		= 4,
	.owner		= THIS_MODULE,
	.make_request	= make_request,
	.run		= run,
	.stop		= stop,
	.status		= status,
	.error_handler	= error,
	.hot_add_disk	= raid5_add_disk,
	.hot_remove_disk= raid5_remove_disk,
	.spare_active	= raid5_spare_active,
	.sync_request	= sync_request,
	.resize		= raid5_resize,
	.quiesce	= raid5_quiesce,
};

static int __init raid5_init(void)
{
	register_md_personality(&raid5_personality);
	register_md_personality(&raid4_personality);
	return 0;
L
Linus Torvalds 已提交
2810 2811
}

2812
static void raid5_exit(void)
L
Linus Torvalds 已提交
2813
{
2814 2815
	unregister_md_personality(&raid5_personality);
	unregister_md_personality(&raid4_personality);
L
Linus Torvalds 已提交
2816 2817 2818 2819 2820 2821
}

module_init(raid5_init);
module_exit(raid5_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS("md-personality-4"); /* RAID5 */
2822 2823
MODULE_ALIAS("md-raid5");
MODULE_ALIAS("md-raid4");
2824 2825
MODULE_ALIAS("md-level-5");
MODULE_ALIAS("md-level-4");