xref: /openbmc/linux/drivers/md/dm-log.c (revision b627b4ed) 
1 /*
2  * Copyright (C) 2003 Sistina Software
3  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4  *
5  * This file is released under the LGPL.
6  */
7 
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/dm-io.h>
13 #include <linux/dm-dirty-log.h>
14 
15 #include <linux/device-mapper.h>
16 
17 #define DM_MSG_PREFIX "dirty region log"
18 
19 static LIST_HEAD(_log_types);
20 static DEFINE_SPINLOCK(_lock);
21 
22 static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
23 {
24 	struct dm_dirty_log_type *log_type;
25 
26 	list_for_each_entry(log_type, &_log_types, list)
27 		if (!strcmp(name, log_type->name))
28 			return log_type;
29 
30 	return NULL;
31 }
32 
33 static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
34 {
35 	struct dm_dirty_log_type *log_type;
36 
37 	spin_lock(&_lock);
38 
39 	log_type = __find_dirty_log_type(name);
40 	if (log_type && !try_module_get(log_type->module))
41 		log_type = NULL;
42 
43 	spin_unlock(&_lock);
44 
45 	return log_type;
46 }
47 
48 /*
49  * get_type
50  * @type_name
51  *
52  * Attempt to retrieve the dm_dirty_log_type by name.  If not already
53  * available, attempt to load the appropriate module.
54  *
55  * Log modules are named "dm-log-" followed by the 'type_name'.
56  * Modules may contain multiple types.
57  * This function will first try the module "dm-log-<type_name>",
58  * then truncate 'type_name' on the last '-' and try again.
59  *
60  * For example, if type_name was "clustered-disk", it would search
61  * 'dm-log-clustered-disk' then 'dm-log-clustered'.
62  *
63  * Returns: dirty_log_type* on success, NULL on failure
64  */
65 static struct dm_dirty_log_type *get_type(const char *type_name)
66 {
67 	char *p, *type_name_dup;
68 	struct dm_dirty_log_type *log_type;
69 
70 	if (!type_name)
71 		return NULL;
72 
73 	log_type = _get_dirty_log_type(type_name);
74 	if (log_type)
75 		return log_type;
76 
77 	type_name_dup = kstrdup(type_name, GFP_KERNEL);
78 	if (!type_name_dup) {
79 		DMWARN("No memory left to attempt log module load for \"%s\"",
80 		       type_name);
81 		return NULL;
82 	}
83 
84 	while (request_module("dm-log-%s", type_name_dup) ||
85 	       !(log_type = _get_dirty_log_type(type_name))) {
86 		p = strrchr(type_name_dup, '-');
87 		if (!p)
88 			break;
89 		p[0] = '\0';
90 	}
91 
92 	if (!log_type)
93 		DMWARN("Module for logging type \"%s\" not found.", type_name);
94 
95 	kfree(type_name_dup);
96 
97 	return log_type;
98 }
99 
100 static void put_type(struct dm_dirty_log_type *type)
101 {
102 	if (!type)
103 		return;
104 
105 	spin_lock(&_lock);
106 	if (!__find_dirty_log_type(type->name))
107 		goto out;
108 
109 	module_put(type->module);
110 
111 out:
112 	spin_unlock(&_lock);
113 }
114 
115 int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
116 {
117 	int r = 0;
118 
119 	spin_lock(&_lock);
120 	if (!__find_dirty_log_type(type->name))
121 		list_add(&type->list, &_log_types);
122 	else
123 		r = -EEXIST;
124 	spin_unlock(&_lock);
125 
126 	return r;
127 }
128 EXPORT_SYMBOL(dm_dirty_log_type_register);
129 
130 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
131 {
132 	spin_lock(&_lock);
133 
134 	if (!__find_dirty_log_type(type->name)) {
135 		spin_unlock(&_lock);
136 		return -EINVAL;
137 	}
138 
139 	list_del(&type->list);
140 
141 	spin_unlock(&_lock);
142 
143 	return 0;
144 }
145 EXPORT_SYMBOL(dm_dirty_log_type_unregister);
146 
147 struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
148 					 struct dm_target *ti,
149 					 unsigned int argc, char **argv)
150 {
151 	struct dm_dirty_log_type *type;
152 	struct dm_dirty_log *log;
153 
154 	log = kmalloc(sizeof(*log), GFP_KERNEL);
155 	if (!log)
156 		return NULL;
157 
158 	type = get_type(type_name);
159 	if (!type) {
160 		kfree(log);
161 		return NULL;
162 	}
163 
164 	log->type = type;
165 	if (type->ctr(log, ti, argc, argv)) {
166 		kfree(log);
167 		put_type(type);
168 		return NULL;
169 	}
170 
171 	return log;
172 }
173 EXPORT_SYMBOL(dm_dirty_log_create);
174 
175 void dm_dirty_log_destroy(struct dm_dirty_log *log)
176 {
177 	log->type->dtr(log);
178 	put_type(log->type);
179 	kfree(log);
180 }
181 EXPORT_SYMBOL(dm_dirty_log_destroy);
182 
183 /*-----------------------------------------------------------------
184  * Persistent and core logs share a lot of their implementation.
185  * FIXME: need a reload method to be called from a resume
186  *---------------------------------------------------------------*/
187 /*
188  * Magic for persistent mirrors: "MiRr"
189  */
190 #define MIRROR_MAGIC 0x4D695272
191 
192 /*
193  * The on-disk version of the metadata.
194  */
195 #define MIRROR_DISK_VERSION 2
196 #define LOG_OFFSET 2
197 
198 struct log_header {
199 	uint32_t magic;
200 
201 	/*
202 	 * Simple, incrementing version. no backward
203 	 * compatibility.
204 	 */
205 	uint32_t version;
206 	sector_t nr_regions;
207 };
208 
209 struct log_c {
210 	struct dm_target *ti;
211 	int touched;
212 	uint32_t region_size;
213 	unsigned int region_count;
214 	region_t sync_count;
215 
216 	unsigned bitset_uint32_count;
217 	uint32_t *clean_bits;
218 	uint32_t *sync_bits;
219 	uint32_t *recovering_bits;	/* FIXME: this seems excessive */
220 
221 	int sync_search;
222 
223 	/* Resync flag */
224 	enum sync {
225 		DEFAULTSYNC,	/* Synchronize if necessary */
226 		NOSYNC,		/* Devices known to be already in sync */
227 		FORCESYNC,	/* Force a sync to happen */
228 	} sync;
229 
230 	struct dm_io_request io_req;
231 
232 	/*
233 	 * Disk log fields
234 	 */
235 	int log_dev_failed;
236 	struct dm_dev *log_dev;
237 	struct log_header header;
238 
239 	struct dm_io_region header_location;
240 	struct log_header *disk_header;
241 };
242 
243 /*
244  * The touched member needs to be updated every time we access
245  * one of the bitsets.
246  */
247 static inline int log_test_bit(uint32_t *bs, unsigned bit)
248 {
249 	return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
250 }
251 
252 static inline void log_set_bit(struct log_c *l,
253 			       uint32_t *bs, unsigned bit)
254 {
255 	ext2_set_bit(bit, (unsigned long *) bs);
256 	l->touched = 1;
257 }
258 
259 static inline void log_clear_bit(struct log_c *l,
260 				 uint32_t *bs, unsigned bit)
261 {
262 	ext2_clear_bit(bit, (unsigned long *) bs);
263 	l->touched = 1;
264 }
265 
266 /*----------------------------------------------------------------
267  * Header IO
268  *--------------------------------------------------------------*/
269 static void header_to_disk(struct log_header *core, struct log_header *disk)
270 {
271 	disk->magic = cpu_to_le32(core->magic);
272 	disk->version = cpu_to_le32(core->version);
273 	disk->nr_regions = cpu_to_le64(core->nr_regions);
274 }
275 
276 static void header_from_disk(struct log_header *core, struct log_header *disk)
277 {
278 	core->magic = le32_to_cpu(disk->magic);
279 	core->version = le32_to_cpu(disk->version);
280 	core->nr_regions = le64_to_cpu(disk->nr_regions);
281 }
282 
283 static int rw_header(struct log_c *lc, int rw)
284 {
285 	lc->io_req.bi_rw = rw;
286 
287 	return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
288 }
289 
290 static int read_header(struct log_c *log)
291 {
292 	int r;
293 
294 	r = rw_header(log, READ);
295 	if (r)
296 		return r;
297 
298 	header_from_disk(&log->header, log->disk_header);
299 
300 	/* New log required? */
301 	if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
302 		log->header.magic = MIRROR_MAGIC;
303 		log->header.version = MIRROR_DISK_VERSION;
304 		log->header.nr_regions = 0;
305 	}
306 
307 #ifdef __LITTLE_ENDIAN
308 	if (log->header.version == 1)
309 		log->header.version = 2;
310 #endif
311 
312 	if (log->header.version != MIRROR_DISK_VERSION) {
313 		DMWARN("incompatible disk log version");
314 		return -EINVAL;
315 	}
316 
317 	return 0;
318 }
319 
320 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
321 {
322 	if (region_size < 2 || region_size > ti->len)
323 		return 0;
324 
325 	if (!is_power_of_2(region_size))
326 		return 0;
327 
328 	return 1;
329 }
330 
331 /*----------------------------------------------------------------
332  * core log constructor/destructor
333  *
334  * argv contains region_size followed optionally by [no]sync
335  *--------------------------------------------------------------*/
336 #define BYTE_SHIFT 3
337 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
338 			      unsigned int argc, char **argv,
339 			      struct dm_dev *dev)
340 {
341 	enum sync sync = DEFAULTSYNC;
342 
343 	struct log_c *lc;
344 	uint32_t region_size;
345 	unsigned int region_count;
346 	size_t bitset_size, buf_size;
347 	int r;
348 
349 	if (argc < 1 || argc > 2) {
350 		DMWARN("wrong number of arguments to dirty region log");
351 		return -EINVAL;
352 	}
353 
354 	if (argc > 1) {
355 		if (!strcmp(argv[1], "sync"))
356 			sync = FORCESYNC;
357 		else if (!strcmp(argv[1], "nosync"))
358 			sync = NOSYNC;
359 		else {
360 			DMWARN("unrecognised sync argument to "
361 			       "dirty region log: %s", argv[1]);
362 			return -EINVAL;
363 		}
364 	}
365 
366 	if (sscanf(argv[0], "%u", &region_size) != 1 ||
367 	    !_check_region_size(ti, region_size)) {
368 		DMWARN("invalid region size %s", argv[0]);
369 		return -EINVAL;
370 	}
371 
372 	region_count = dm_sector_div_up(ti->len, region_size);
373 
374 	lc = kmalloc(sizeof(*lc), GFP_KERNEL);
375 	if (!lc) {
376 		DMWARN("couldn't allocate core log");
377 		return -ENOMEM;
378 	}
379 
380 	lc->ti = ti;
381 	lc->touched = 0;
382 	lc->region_size = region_size;
383 	lc->region_count = region_count;
384 	lc->sync = sync;
385 
386 	/*
387 	 * Work out how many "unsigned long"s we need to hold the bitset.
388 	 */
389 	bitset_size = dm_round_up(region_count,
390 				  sizeof(*lc->clean_bits) << BYTE_SHIFT);
391 	bitset_size >>= BYTE_SHIFT;
392 
393 	lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
394 
395 	/*
396 	 * Disk log?
397 	 */
398 	if (!dev) {
399 		lc->clean_bits = vmalloc(bitset_size);
400 		if (!lc->clean_bits) {
401 			DMWARN("couldn't allocate clean bitset");
402 			kfree(lc);
403 			return -ENOMEM;
404 		}
405 		lc->disk_header = NULL;
406 	} else {
407 		lc->log_dev = dev;
408 		lc->log_dev_failed = 0;
409 		lc->header_location.bdev = lc->log_dev->bdev;
410 		lc->header_location.sector = 0;
411 
412 		/*
413 		 * Buffer holds both header and bitset.
414 		 */
415 		buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
416 				       bitset_size, ti->limits.hardsect_size);
417 
418 		if (buf_size > dev->bdev->bd_inode->i_size) {
419 			DMWARN("log device %s too small: need %llu bytes",
420 				dev->name, (unsigned long long)buf_size);
421 			kfree(lc);
422 			return -EINVAL;
423 		}
424 
425 		lc->header_location.count = buf_size >> SECTOR_SHIFT;
426 
427 		lc->io_req.mem.type = DM_IO_VMA;
428 		lc->io_req.notify.fn = NULL;
429 		lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
430 								   PAGE_SIZE));
431 		if (IS_ERR(lc->io_req.client)) {
432 			r = PTR_ERR(lc->io_req.client);
433 			DMWARN("couldn't allocate disk io client");
434 			kfree(lc);
435 			return -ENOMEM;
436 		}
437 
438 		lc->disk_header = vmalloc(buf_size);
439 		if (!lc->disk_header) {
440 			DMWARN("couldn't allocate disk log buffer");
441 			dm_io_client_destroy(lc->io_req.client);
442 			kfree(lc);
443 			return -ENOMEM;
444 		}
445 
446 		lc->io_req.mem.ptr.vma = lc->disk_header;
447 		lc->clean_bits = (void *)lc->disk_header +
448 				 (LOG_OFFSET << SECTOR_SHIFT);
449 	}
450 
451 	memset(lc->clean_bits, -1, bitset_size);
452 
453 	lc->sync_bits = vmalloc(bitset_size);
454 	if (!lc->sync_bits) {
455 		DMWARN("couldn't allocate sync bitset");
456 		if (!dev)
457 			vfree(lc->clean_bits);
458 		else
459 			dm_io_client_destroy(lc->io_req.client);
460 		vfree(lc->disk_header);
461 		kfree(lc);
462 		return -ENOMEM;
463 	}
464 	memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
465 	lc->sync_count = (sync == NOSYNC) ? region_count : 0;
466 
467 	lc->recovering_bits = vmalloc(bitset_size);
468 	if (!lc->recovering_bits) {
469 		DMWARN("couldn't allocate sync bitset");
470 		vfree(lc->sync_bits);
471 		if (!dev)
472 			vfree(lc->clean_bits);
473 		else
474 			dm_io_client_destroy(lc->io_req.client);
475 		vfree(lc->disk_header);
476 		kfree(lc);
477 		return -ENOMEM;
478 	}
479 	memset(lc->recovering_bits, 0, bitset_size);
480 	lc->sync_search = 0;
481 	log->context = lc;
482 
483 	return 0;
484 }
485 
486 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
487 		    unsigned int argc, char **argv)
488 {
489 	return create_log_context(log, ti, argc, argv, NULL);
490 }
491 
492 static void destroy_log_context(struct log_c *lc)
493 {
494 	vfree(lc->sync_bits);
495 	vfree(lc->recovering_bits);
496 	kfree(lc);
497 }
498 
499 static void core_dtr(struct dm_dirty_log *log)
500 {
501 	struct log_c *lc = (struct log_c *) log->context;
502 
503 	vfree(lc->clean_bits);
504 	destroy_log_context(lc);
505 }
506 
507 /*----------------------------------------------------------------
508  * disk log constructor/destructor
509  *
510  * argv contains log_device region_size followed optionally by [no]sync
511  *--------------------------------------------------------------*/
512 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
513 		    unsigned int argc, char **argv)
514 {
515 	int r;
516 	struct dm_dev *dev;
517 
518 	if (argc < 2 || argc > 3) {
519 		DMWARN("wrong number of arguments to disk dirty region log");
520 		return -EINVAL;
521 	}
522 
523 	r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
524 			  FMODE_READ | FMODE_WRITE, &dev);
525 	if (r)
526 		return r;
527 
528 	r = create_log_context(log, ti, argc - 1, argv + 1, dev);
529 	if (r) {
530 		dm_put_device(ti, dev);
531 		return r;
532 	}
533 
534 	return 0;
535 }
536 
537 static void disk_dtr(struct dm_dirty_log *log)
538 {
539 	struct log_c *lc = (struct log_c *) log->context;
540 
541 	dm_put_device(lc->ti, lc->log_dev);
542 	vfree(lc->disk_header);
543 	dm_io_client_destroy(lc->io_req.client);
544 	destroy_log_context(lc);
545 }
546 
547 static int count_bits32(uint32_t *addr, unsigned size)
548 {
549 	int count = 0, i;
550 
551 	for (i = 0; i < size; i++) {
552 		count += hweight32(*(addr+i));
553 	}
554 	return count;
555 }
556 
557 static void fail_log_device(struct log_c *lc)
558 {
559 	if (lc->log_dev_failed)
560 		return;
561 
562 	lc->log_dev_failed = 1;
563 	dm_table_event(lc->ti->table);
564 }
565 
566 static int disk_resume(struct dm_dirty_log *log)
567 {
568 	int r;
569 	unsigned i;
570 	struct log_c *lc = (struct log_c *) log->context;
571 	size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
572 
573 	/* read the disk header */
574 	r = read_header(lc);
575 	if (r) {
576 		DMWARN("%s: Failed to read header on dirty region log device",
577 		       lc->log_dev->name);
578 		fail_log_device(lc);
579 		/*
580 		 * If the log device cannot be read, we must assume
581 		 * all regions are out-of-sync.  If we simply return
582 		 * here, the state will be uninitialized and could
583 		 * lead us to return 'in-sync' status for regions
584 		 * that are actually 'out-of-sync'.
585 		 */
586 		lc->header.nr_regions = 0;
587 	}
588 
589 	/* set or clear any new bits -- device has grown */
590 	if (lc->sync == NOSYNC)
591 		for (i = lc->header.nr_regions; i < lc->region_count; i++)
592 			/* FIXME: amazingly inefficient */
593 			log_set_bit(lc, lc->clean_bits, i);
594 	else
595 		for (i = lc->header.nr_regions; i < lc->region_count; i++)
596 			/* FIXME: amazingly inefficient */
597 			log_clear_bit(lc, lc->clean_bits, i);
598 
599 	/* clear any old bits -- device has shrunk */
600 	for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
601 		log_clear_bit(lc, lc->clean_bits, i);
602 
603 	/* copy clean across to sync */
604 	memcpy(lc->sync_bits, lc->clean_bits, size);
605 	lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
606 	lc->sync_search = 0;
607 
608 	/* set the correct number of regions in the header */
609 	lc->header.nr_regions = lc->region_count;
610 
611 	header_to_disk(&lc->header, lc->disk_header);
612 
613 	/* write the new header */
614 	r = rw_header(lc, WRITE);
615 	if (r) {
616 		DMWARN("%s: Failed to write header on dirty region log device",
617 		       lc->log_dev->name);
618 		fail_log_device(lc);
619 	}
620 
621 	return r;
622 }
623 
624 static uint32_t core_get_region_size(struct dm_dirty_log *log)
625 {
626 	struct log_c *lc = (struct log_c *) log->context;
627 	return lc->region_size;
628 }
629 
630 static int core_resume(struct dm_dirty_log *log)
631 {
632 	struct log_c *lc = (struct log_c *) log->context;
633 	lc->sync_search = 0;
634 	return 0;
635 }
636 
637 static int core_is_clean(struct dm_dirty_log *log, region_t region)
638 {
639 	struct log_c *lc = (struct log_c *) log->context;
640 	return log_test_bit(lc->clean_bits, region);
641 }
642 
643 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
644 {
645 	struct log_c *lc = (struct log_c *) log->context;
646 	return log_test_bit(lc->sync_bits, region);
647 }
648 
649 static int core_flush(struct dm_dirty_log *log)
650 {
651 	/* no op */
652 	return 0;
653 }
654 
655 static int disk_flush(struct dm_dirty_log *log)
656 {
657 	int r;
658 	struct log_c *lc = (struct log_c *) log->context;
659 
660 	/* only write if the log has changed */
661 	if (!lc->touched)
662 		return 0;
663 
664 	r = rw_header(lc, WRITE);
665 	if (r)
666 		fail_log_device(lc);
667 	else
668 		lc->touched = 0;
669 
670 	return r;
671 }
672 
673 static void core_mark_region(struct dm_dirty_log *log, region_t region)
674 {
675 	struct log_c *lc = (struct log_c *) log->context;
676 	log_clear_bit(lc, lc->clean_bits, region);
677 }
678 
679 static void core_clear_region(struct dm_dirty_log *log, region_t region)
680 {
681 	struct log_c *lc = (struct log_c *) log->context;
682 	log_set_bit(lc, lc->clean_bits, region);
683 }
684 
685 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
686 {
687 	struct log_c *lc = (struct log_c *) log->context;
688 
689 	if (lc->sync_search >= lc->region_count)
690 		return 0;
691 
692 	do {
693 		*region = ext2_find_next_zero_bit(
694 					     (unsigned long *) lc->sync_bits,
695 					     lc->region_count,
696 					     lc->sync_search);
697 		lc->sync_search = *region + 1;
698 
699 		if (*region >= lc->region_count)
700 			return 0;
701 
702 	} while (log_test_bit(lc->recovering_bits, *region));
703 
704 	log_set_bit(lc, lc->recovering_bits, *region);
705 	return 1;
706 }
707 
708 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
709 				 int in_sync)
710 {
711 	struct log_c *lc = (struct log_c *) log->context;
712 
713 	log_clear_bit(lc, lc->recovering_bits, region);
714 	if (in_sync) {
715 		log_set_bit(lc, lc->sync_bits, region);
716                 lc->sync_count++;
717         } else if (log_test_bit(lc->sync_bits, region)) {
718 		lc->sync_count--;
719 		log_clear_bit(lc, lc->sync_bits, region);
720 	}
721 }
722 
723 static region_t core_get_sync_count(struct dm_dirty_log *log)
724 {
725         struct log_c *lc = (struct log_c *) log->context;
726 
727         return lc->sync_count;
728 }
729 
730 #define	DMEMIT_SYNC \
731 	if (lc->sync != DEFAULTSYNC) \
732 		DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
733 
734 static int core_status(struct dm_dirty_log *log, status_type_t status,
735 		       char *result, unsigned int maxlen)
736 {
737 	int sz = 0;
738 	struct log_c *lc = log->context;
739 
740 	switch(status) {
741 	case STATUSTYPE_INFO:
742 		DMEMIT("1 %s", log->type->name);
743 		break;
744 
745 	case STATUSTYPE_TABLE:
746 		DMEMIT("%s %u %u ", log->type->name,
747 		       lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
748 		DMEMIT_SYNC;
749 	}
750 
751 	return sz;
752 }
753 
754 static int disk_status(struct dm_dirty_log *log, status_type_t status,
755 		       char *result, unsigned int maxlen)
756 {
757 	int sz = 0;
758 	struct log_c *lc = log->context;
759 
760 	switch(status) {
761 	case STATUSTYPE_INFO:
762 		DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
763 		       lc->log_dev_failed ? 'D' : 'A');
764 		break;
765 
766 	case STATUSTYPE_TABLE:
767 		DMEMIT("%s %u %s %u ", log->type->name,
768 		       lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
769 		       lc->region_size);
770 		DMEMIT_SYNC;
771 	}
772 
773 	return sz;
774 }
775 
776 static struct dm_dirty_log_type _core_type = {
777 	.name = "core",
778 	.module = THIS_MODULE,
779 	.ctr = core_ctr,
780 	.dtr = core_dtr,
781 	.resume = core_resume,
782 	.get_region_size = core_get_region_size,
783 	.is_clean = core_is_clean,
784 	.in_sync = core_in_sync,
785 	.flush = core_flush,
786 	.mark_region = core_mark_region,
787 	.clear_region = core_clear_region,
788 	.get_resync_work = core_get_resync_work,
789 	.set_region_sync = core_set_region_sync,
790 	.get_sync_count = core_get_sync_count,
791 	.status = core_status,
792 };
793 
794 static struct dm_dirty_log_type _disk_type = {
795 	.name = "disk",
796 	.module = THIS_MODULE,
797 	.ctr = disk_ctr,
798 	.dtr = disk_dtr,
799 	.postsuspend = disk_flush,
800 	.resume = disk_resume,
801 	.get_region_size = core_get_region_size,
802 	.is_clean = core_is_clean,
803 	.in_sync = core_in_sync,
804 	.flush = disk_flush,
805 	.mark_region = core_mark_region,
806 	.clear_region = core_clear_region,
807 	.get_resync_work = core_get_resync_work,
808 	.set_region_sync = core_set_region_sync,
809 	.get_sync_count = core_get_sync_count,
810 	.status = disk_status,
811 };
812 
813 static int __init dm_dirty_log_init(void)
814 {
815 	int r;
816 
817 	r = dm_dirty_log_type_register(&_core_type);
818 	if (r)
819 		DMWARN("couldn't register core log");
820 
821 	r = dm_dirty_log_type_register(&_disk_type);
822 	if (r) {
823 		DMWARN("couldn't register disk type");
824 		dm_dirty_log_type_unregister(&_core_type);
825 	}
826 
827 	return r;
828 }
829 
830 static void __exit dm_dirty_log_exit(void)
831 {
832 	dm_dirty_log_type_unregister(&_disk_type);
833 	dm_dirty_log_type_unregister(&_core_type);
834 }
835 
836 module_init(dm_dirty_log_init);
837 module_exit(dm_dirty_log_exit);
838 
839 MODULE_DESCRIPTION(DM_NAME " dirty region log");
840 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
841 MODULE_LICENSE("GPL");
842