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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
19static LIST_HEAD(_log_types);
20static DEFINE_SPINLOCK(_lock);
21
22static 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
33static 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 */
65static 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
100static 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
111out:
112 spin_unlock(&_lock);
113}
114
115int 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}
128EXPORT_SYMBOL(dm_dirty_log_type_register);
129
130int 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}
145EXPORT_SYMBOL(dm_dirty_log_type_unregister);
146
147struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
148 struct dm_target *ti,
149 int (*flush_callback_fn)(struct dm_target *ti),
150 unsigned int argc, char **argv)
151{
152 struct dm_dirty_log_type *type;
153 struct dm_dirty_log *log;
154
155 log = kmalloc(sizeof(*log), GFP_KERNEL);
156 if (!log)
157 return NULL;
158
159 type = get_type(type_name);
160 if (!type) {
161 kfree(log);
162 return NULL;
163 }
164
165 log->flush_callback_fn = flush_callback_fn;
166 log->type = type;
167 if (type->ctr(log, ti, argc, argv)) {
168 kfree(log);
169 put_type(type);
170 return NULL;
171 }
172
173 return log;
174}
175EXPORT_SYMBOL(dm_dirty_log_create);
176
177void dm_dirty_log_destroy(struct dm_dirty_log *log)
178{
179 log->type->dtr(log);
180 put_type(log->type);
181 kfree(log);
182}
183EXPORT_SYMBOL(dm_dirty_log_destroy);
184
185/*-----------------------------------------------------------------
186 * Persistent and core logs share a lot of their implementation.
187 * FIXME: need a reload method to be called from a resume
188 *---------------------------------------------------------------*/
189/*
190 * Magic for persistent mirrors: "MiRr"
191 */
192#define MIRROR_MAGIC 0x4D695272
193
194/*
195 * The on-disk version of the metadata.
196 */
197#define MIRROR_DISK_VERSION 2
198#define LOG_OFFSET 2
199
200struct log_header_disk {
201 __le32 magic;
202
203 /*
204 * Simple, incrementing version. no backward
205 * compatibility.
206 */
207 __le32 version;
208 __le64 nr_regions;
209} __packed;
210
211struct log_header_core {
212 uint32_t magic;
213 uint32_t version;
214 uint64_t nr_regions;
215};
216
217struct log_c {
218 struct dm_target *ti;
219 int touched_dirtied;
220 int touched_cleaned;
221 int flush_failed;
222 uint32_t region_size;
223 unsigned int region_count;
224 region_t sync_count;
225
226 unsigned bitset_uint32_count;
227 uint32_t *clean_bits;
228 uint32_t *sync_bits;
229 uint32_t *recovering_bits; /* FIXME: this seems excessive */
230
231 int sync_search;
232
233 /* Resync flag */
234 enum sync {
235 DEFAULTSYNC, /* Synchronize if necessary */
236 NOSYNC, /* Devices known to be already in sync */
237 FORCESYNC, /* Force a sync to happen */
238 } sync;
239
240 struct dm_io_request io_req;
241
242 /*
243 * Disk log fields
244 */
245 int log_dev_failed;
246 int log_dev_flush_failed;
247 struct dm_dev *log_dev;
248 struct log_header_core header;
249
250 struct dm_io_region header_location;
251 struct log_header_disk *disk_header;
252};
253
254/*
255 * The touched member needs to be updated every time we access
256 * one of the bitsets.
257 */
258static inline int log_test_bit(uint32_t *bs, unsigned bit)
259{
260 return test_bit_le(bit, bs) ? 1 : 0;
261}
262
263static inline void log_set_bit(struct log_c *l,
264 uint32_t *bs, unsigned bit)
265{
266 __set_bit_le(bit, bs);
267 l->touched_cleaned = 1;
268}
269
270static inline void log_clear_bit(struct log_c *l,
271 uint32_t *bs, unsigned bit)
272{
273 __clear_bit_le(bit, bs);
274 l->touched_dirtied = 1;
275}
276
277/*----------------------------------------------------------------
278 * Header IO
279 *--------------------------------------------------------------*/
280static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
281{
282 disk->magic = cpu_to_le32(core->magic);
283 disk->version = cpu_to_le32(core->version);
284 disk->nr_regions = cpu_to_le64(core->nr_regions);
285}
286
287static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
288{
289 core->magic = le32_to_cpu(disk->magic);
290 core->version = le32_to_cpu(disk->version);
291 core->nr_regions = le64_to_cpu(disk->nr_regions);
292}
293
294static int rw_header(struct log_c *lc, int op)
295{
296 lc->io_req.bi_op = op;
297 lc->io_req.bi_op_flags = 0;
298
299 return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
300}
301
302static int flush_header(struct log_c *lc)
303{
304 struct dm_io_region null_location = {
305 .bdev = lc->header_location.bdev,
306 .sector = 0,
307 .count = 0,
308 };
309
310 lc->io_req.bi_op = REQ_OP_WRITE;
311 lc->io_req.bi_op_flags = REQ_PREFLUSH;
312
313 return dm_io(&lc->io_req, 1, &null_location, NULL);
314}
315
316static int read_header(struct log_c *log)
317{
318 int r;
319
320 r = rw_header(log, REQ_OP_READ);
321 if (r)
322 return r;
323
324 header_from_disk(&log->header, log->disk_header);
325
326 /* New log required? */
327 if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
328 log->header.magic = MIRROR_MAGIC;
329 log->header.version = MIRROR_DISK_VERSION;
330 log->header.nr_regions = 0;
331 }
332
333#ifdef __LITTLE_ENDIAN
334 if (log->header.version == 1)
335 log->header.version = 2;
336#endif
337
338 if (log->header.version != MIRROR_DISK_VERSION) {
339 DMWARN("incompatible disk log version");
340 return -EINVAL;
341 }
342
343 return 0;
344}
345
346static int _check_region_size(struct dm_target *ti, uint32_t region_size)
347{
348 if (region_size < 2 || region_size > ti->len)
349 return 0;
350
351 if (!is_power_of_2(region_size))
352 return 0;
353
354 return 1;
355}
356
357/*----------------------------------------------------------------
358 * core log constructor/destructor
359 *
360 * argv contains region_size followed optionally by [no]sync
361 *--------------------------------------------------------------*/
362#define BYTE_SHIFT 3
363static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
364 unsigned int argc, char **argv,
365 struct dm_dev *dev)
366{
367 enum sync sync = DEFAULTSYNC;
368
369 struct log_c *lc;
370 uint32_t region_size;
371 unsigned int region_count;
372 size_t bitset_size, buf_size;
373 int r;
374 char dummy;
375
376 if (argc < 1 || argc > 2) {
377 DMWARN("wrong number of arguments to dirty region log");
378 return -EINVAL;
379 }
380
381 if (argc > 1) {
382 if (!strcmp(argv[1], "sync"))
383 sync = FORCESYNC;
384 else if (!strcmp(argv[1], "nosync"))
385 sync = NOSYNC;
386 else {
387 DMWARN("unrecognised sync argument to "
388 "dirty region log: %s", argv[1]);
389 return -EINVAL;
390 }
391 }
392
393 if (sscanf(argv[0], "%u%c", ®ion_size, &dummy) != 1 ||
394 !_check_region_size(ti, region_size)) {
395 DMWARN("invalid region size %s", argv[0]);
396 return -EINVAL;
397 }
398
399 region_count = dm_sector_div_up(ti->len, region_size);
400
401 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
402 if (!lc) {
403 DMWARN("couldn't allocate core log");
404 return -ENOMEM;
405 }
406
407 lc->ti = ti;
408 lc->touched_dirtied = 0;
409 lc->touched_cleaned = 0;
410 lc->flush_failed = 0;
411 lc->region_size = region_size;
412 lc->region_count = region_count;
413 lc->sync = sync;
414
415 /*
416 * Work out how many "unsigned long"s we need to hold the bitset.
417 */
418 bitset_size = dm_round_up(region_count,
419 sizeof(*lc->clean_bits) << BYTE_SHIFT);
420 bitset_size >>= BYTE_SHIFT;
421
422 lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
423
424 /*
425 * Disk log?
426 */
427 if (!dev) {
428 lc->clean_bits = vmalloc(bitset_size);
429 if (!lc->clean_bits) {
430 DMWARN("couldn't allocate clean bitset");
431 kfree(lc);
432 return -ENOMEM;
433 }
434 lc->disk_header = NULL;
435 } else {
436 lc->log_dev = dev;
437 lc->log_dev_failed = 0;
438 lc->log_dev_flush_failed = 0;
439 lc->header_location.bdev = lc->log_dev->bdev;
440 lc->header_location.sector = 0;
441
442 /*
443 * Buffer holds both header and bitset.
444 */
445 buf_size =
446 dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
447 bdev_logical_block_size(lc->header_location.
448 bdev));
449
450 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
451 DMWARN("log device %s too small: need %llu bytes",
452 dev->name, (unsigned long long)buf_size);
453 kfree(lc);
454 return -EINVAL;
455 }
456
457 lc->header_location.count = buf_size >> SECTOR_SHIFT;
458
459 lc->io_req.mem.type = DM_IO_VMA;
460 lc->io_req.notify.fn = NULL;
461 lc->io_req.client = dm_io_client_create();
462 if (IS_ERR(lc->io_req.client)) {
463 r = PTR_ERR(lc->io_req.client);
464 DMWARN("couldn't allocate disk io client");
465 kfree(lc);
466 return r;
467 }
468
469 lc->disk_header = vmalloc(buf_size);
470 if (!lc->disk_header) {
471 DMWARN("couldn't allocate disk log buffer");
472 dm_io_client_destroy(lc->io_req.client);
473 kfree(lc);
474 return -ENOMEM;
475 }
476
477 lc->io_req.mem.ptr.vma = lc->disk_header;
478 lc->clean_bits = (void *)lc->disk_header +
479 (LOG_OFFSET << SECTOR_SHIFT);
480 }
481
482 memset(lc->clean_bits, -1, bitset_size);
483
484 lc->sync_bits = vmalloc(bitset_size);
485 if (!lc->sync_bits) {
486 DMWARN("couldn't allocate sync bitset");
487 if (!dev)
488 vfree(lc->clean_bits);
489 else
490 dm_io_client_destroy(lc->io_req.client);
491 vfree(lc->disk_header);
492 kfree(lc);
493 return -ENOMEM;
494 }
495 memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
496 lc->sync_count = (sync == NOSYNC) ? region_count : 0;
497
498 lc->recovering_bits = vzalloc(bitset_size);
499 if (!lc->recovering_bits) {
500 DMWARN("couldn't allocate sync bitset");
501 vfree(lc->sync_bits);
502 if (!dev)
503 vfree(lc->clean_bits);
504 else
505 dm_io_client_destroy(lc->io_req.client);
506 vfree(lc->disk_header);
507 kfree(lc);
508 return -ENOMEM;
509 }
510 lc->sync_search = 0;
511 log->context = lc;
512
513 return 0;
514}
515
516static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
517 unsigned int argc, char **argv)
518{
519 return create_log_context(log, ti, argc, argv, NULL);
520}
521
522static void destroy_log_context(struct log_c *lc)
523{
524 vfree(lc->sync_bits);
525 vfree(lc->recovering_bits);
526 kfree(lc);
527}
528
529static void core_dtr(struct dm_dirty_log *log)
530{
531 struct log_c *lc = (struct log_c *) log->context;
532
533 vfree(lc->clean_bits);
534 destroy_log_context(lc);
535}
536
537/*----------------------------------------------------------------
538 * disk log constructor/destructor
539 *
540 * argv contains log_device region_size followed optionally by [no]sync
541 *--------------------------------------------------------------*/
542static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
543 unsigned int argc, char **argv)
544{
545 int r;
546 struct dm_dev *dev;
547
548 if (argc < 2 || argc > 3) {
549 DMWARN("wrong number of arguments to disk dirty region log");
550 return -EINVAL;
551 }
552
553 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
554 if (r)
555 return r;
556
557 r = create_log_context(log, ti, argc - 1, argv + 1, dev);
558 if (r) {
559 dm_put_device(ti, dev);
560 return r;
561 }
562
563 return 0;
564}
565
566static void disk_dtr(struct dm_dirty_log *log)
567{
568 struct log_c *lc = (struct log_c *) log->context;
569
570 dm_put_device(lc->ti, lc->log_dev);
571 vfree(lc->disk_header);
572 dm_io_client_destroy(lc->io_req.client);
573 destroy_log_context(lc);
574}
575
576static void fail_log_device(struct log_c *lc)
577{
578 if (lc->log_dev_failed)
579 return;
580
581 lc->log_dev_failed = 1;
582 dm_table_event(lc->ti->table);
583}
584
585static int disk_resume(struct dm_dirty_log *log)
586{
587 int r;
588 unsigned i;
589 struct log_c *lc = (struct log_c *) log->context;
590 size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
591
592 /* read the disk header */
593 r = read_header(lc);
594 if (r) {
595 DMWARN("%s: Failed to read header on dirty region log device",
596 lc->log_dev->name);
597 fail_log_device(lc);
598 /*
599 * If the log device cannot be read, we must assume
600 * all regions are out-of-sync. If we simply return
601 * here, the state will be uninitialized and could
602 * lead us to return 'in-sync' status for regions
603 * that are actually 'out-of-sync'.
604 */
605 lc->header.nr_regions = 0;
606 }
607
608 /* set or clear any new bits -- device has grown */
609 if (lc->sync == NOSYNC)
610 for (i = lc->header.nr_regions; i < lc->region_count; i++)
611 /* FIXME: amazingly inefficient */
612 log_set_bit(lc, lc->clean_bits, i);
613 else
614 for (i = lc->header.nr_regions; i < lc->region_count; i++)
615 /* FIXME: amazingly inefficient */
616 log_clear_bit(lc, lc->clean_bits, i);
617
618 /* clear any old bits -- device has shrunk */
619 for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
620 log_clear_bit(lc, lc->clean_bits, i);
621
622 /* copy clean across to sync */
623 memcpy(lc->sync_bits, lc->clean_bits, size);
624 lc->sync_count = memweight(lc->clean_bits,
625 lc->bitset_uint32_count * sizeof(uint32_t));
626 lc->sync_search = 0;
627
628 /* set the correct number of regions in the header */
629 lc->header.nr_regions = lc->region_count;
630
631 header_to_disk(&lc->header, lc->disk_header);
632
633 /* write the new header */
634 r = rw_header(lc, REQ_OP_WRITE);
635 if (!r) {
636 r = flush_header(lc);
637 if (r)
638 lc->log_dev_flush_failed = 1;
639 }
640 if (r) {
641 DMWARN("%s: Failed to write header on dirty region log device",
642 lc->log_dev->name);
643 fail_log_device(lc);
644 }
645
646 return r;
647}
648
649static uint32_t core_get_region_size(struct dm_dirty_log *log)
650{
651 struct log_c *lc = (struct log_c *) log->context;
652 return lc->region_size;
653}
654
655static int core_resume(struct dm_dirty_log *log)
656{
657 struct log_c *lc = (struct log_c *) log->context;
658 lc->sync_search = 0;
659 return 0;
660}
661
662static int core_is_clean(struct dm_dirty_log *log, region_t region)
663{
664 struct log_c *lc = (struct log_c *) log->context;
665 return log_test_bit(lc->clean_bits, region);
666}
667
668static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
669{
670 struct log_c *lc = (struct log_c *) log->context;
671 return log_test_bit(lc->sync_bits, region);
672}
673
674static int core_flush(struct dm_dirty_log *log)
675{
676 /* no op */
677 return 0;
678}
679
680static int disk_flush(struct dm_dirty_log *log)
681{
682 int r, i;
683 struct log_c *lc = log->context;
684
685 /* only write if the log has changed */
686 if (!lc->touched_cleaned && !lc->touched_dirtied)
687 return 0;
688
689 if (lc->touched_cleaned && log->flush_callback_fn &&
690 log->flush_callback_fn(lc->ti)) {
691 /*
692 * At this point it is impossible to determine which
693 * regions are clean and which are dirty (without
694 * re-reading the log off disk). So mark all of them
695 * dirty.
696 */
697 lc->flush_failed = 1;
698 for (i = 0; i < lc->region_count; i++)
699 log_clear_bit(lc, lc->clean_bits, i);
700 }
701
702 r = rw_header(lc, REQ_OP_WRITE);
703 if (r)
704 fail_log_device(lc);
705 else {
706 if (lc->touched_dirtied) {
707 r = flush_header(lc);
708 if (r) {
709 lc->log_dev_flush_failed = 1;
710 fail_log_device(lc);
711 } else
712 lc->touched_dirtied = 0;
713 }
714 lc->touched_cleaned = 0;
715 }
716
717 return r;
718}
719
720static void core_mark_region(struct dm_dirty_log *log, region_t region)
721{
722 struct log_c *lc = (struct log_c *) log->context;
723 log_clear_bit(lc, lc->clean_bits, region);
724}
725
726static void core_clear_region(struct dm_dirty_log *log, region_t region)
727{
728 struct log_c *lc = (struct log_c *) log->context;
729 if (likely(!lc->flush_failed))
730 log_set_bit(lc, lc->clean_bits, region);
731}
732
733static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
734{
735 struct log_c *lc = (struct log_c *) log->context;
736
737 if (lc->sync_search >= lc->region_count)
738 return 0;
739
740 do {
741 *region = find_next_zero_bit_le(lc->sync_bits,
742 lc->region_count,
743 lc->sync_search);
744 lc->sync_search = *region + 1;
745
746 if (*region >= lc->region_count)
747 return 0;
748
749 } while (log_test_bit(lc->recovering_bits, *region));
750
751 log_set_bit(lc, lc->recovering_bits, *region);
752 return 1;
753}
754
755static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
756 int in_sync)
757{
758 struct log_c *lc = (struct log_c *) log->context;
759
760 log_clear_bit(lc, lc->recovering_bits, region);
761 if (in_sync) {
762 log_set_bit(lc, lc->sync_bits, region);
763 lc->sync_count++;
764 } else if (log_test_bit(lc->sync_bits, region)) {
765 lc->sync_count--;
766 log_clear_bit(lc, lc->sync_bits, region);
767 }
768}
769
770static region_t core_get_sync_count(struct dm_dirty_log *log)
771{
772 struct log_c *lc = (struct log_c *) log->context;
773
774 return lc->sync_count;
775}
776
777#define DMEMIT_SYNC \
778 if (lc->sync != DEFAULTSYNC) \
779 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
780
781static int core_status(struct dm_dirty_log *log, status_type_t status,
782 char *result, unsigned int maxlen)
783{
784 int sz = 0;
785 struct log_c *lc = log->context;
786
787 switch(status) {
788 case STATUSTYPE_INFO:
789 DMEMIT("1 %s", log->type->name);
790 break;
791
792 case STATUSTYPE_TABLE:
793 DMEMIT("%s %u %u ", log->type->name,
794 lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
795 DMEMIT_SYNC;
796 }
797
798 return sz;
799}
800
801static int disk_status(struct dm_dirty_log *log, status_type_t status,
802 char *result, unsigned int maxlen)
803{
804 int sz = 0;
805 struct log_c *lc = log->context;
806
807 switch(status) {
808 case STATUSTYPE_INFO:
809 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
810 lc->log_dev_flush_failed ? 'F' :
811 lc->log_dev_failed ? 'D' :
812 'A');
813 break;
814
815 case STATUSTYPE_TABLE:
816 DMEMIT("%s %u %s %u ", log->type->name,
817 lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
818 lc->region_size);
819 DMEMIT_SYNC;
820 }
821
822 return sz;
823}
824
825static struct dm_dirty_log_type _core_type = {
826 .name = "core",
827 .module = THIS_MODULE,
828 .ctr = core_ctr,
829 .dtr = core_dtr,
830 .resume = core_resume,
831 .get_region_size = core_get_region_size,
832 .is_clean = core_is_clean,
833 .in_sync = core_in_sync,
834 .flush = core_flush,
835 .mark_region = core_mark_region,
836 .clear_region = core_clear_region,
837 .get_resync_work = core_get_resync_work,
838 .set_region_sync = core_set_region_sync,
839 .get_sync_count = core_get_sync_count,
840 .status = core_status,
841};
842
843static struct dm_dirty_log_type _disk_type = {
844 .name = "disk",
845 .module = THIS_MODULE,
846 .ctr = disk_ctr,
847 .dtr = disk_dtr,
848 .postsuspend = disk_flush,
849 .resume = disk_resume,
850 .get_region_size = core_get_region_size,
851 .is_clean = core_is_clean,
852 .in_sync = core_in_sync,
853 .flush = disk_flush,
854 .mark_region = core_mark_region,
855 .clear_region = core_clear_region,
856 .get_resync_work = core_get_resync_work,
857 .set_region_sync = core_set_region_sync,
858 .get_sync_count = core_get_sync_count,
859 .status = disk_status,
860};
861
862static int __init dm_dirty_log_init(void)
863{
864 int r;
865
866 r = dm_dirty_log_type_register(&_core_type);
867 if (r)
868 DMWARN("couldn't register core log");
869
870 r = dm_dirty_log_type_register(&_disk_type);
871 if (r) {
872 DMWARN("couldn't register disk type");
873 dm_dirty_log_type_unregister(&_core_type);
874 }
875
876 return r;
877}
878
879static void __exit dm_dirty_log_exit(void)
880{
881 dm_dirty_log_type_unregister(&_disk_type);
882 dm_dirty_log_type_unregister(&_core_type);
883}
884
885module_init(dm_dirty_log_init);
886module_exit(dm_dirty_log_exit);
887
888MODULE_DESCRIPTION(DM_NAME " dirty region log");
889MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
890MODULE_LICENSE("GPL");
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
19static LIST_HEAD(_log_types);
20static DEFINE_SPINLOCK(_lock);
21
22static 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
33static 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 */
65static 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
100static 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
111out:
112 spin_unlock(&_lock);
113}
114
115int 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}
128EXPORT_SYMBOL(dm_dirty_log_type_register);
129
130int 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}
145EXPORT_SYMBOL(dm_dirty_log_type_unregister);
146
147struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
148 struct dm_target *ti,
149 int (*flush_callback_fn)(struct dm_target *ti),
150 unsigned int argc, char **argv)
151{
152 struct dm_dirty_log_type *type;
153 struct dm_dirty_log *log;
154
155 log = kmalloc(sizeof(*log), GFP_KERNEL);
156 if (!log)
157 return NULL;
158
159 type = get_type(type_name);
160 if (!type) {
161 kfree(log);
162 return NULL;
163 }
164
165 log->flush_callback_fn = flush_callback_fn;
166 log->type = type;
167 if (type->ctr(log, ti, argc, argv)) {
168 kfree(log);
169 put_type(type);
170 return NULL;
171 }
172
173 return log;
174}
175EXPORT_SYMBOL(dm_dirty_log_create);
176
177void dm_dirty_log_destroy(struct dm_dirty_log *log)
178{
179 log->type->dtr(log);
180 put_type(log->type);
181 kfree(log);
182}
183EXPORT_SYMBOL(dm_dirty_log_destroy);
184
185/*-----------------------------------------------------------------
186 * Persistent and core logs share a lot of their implementation.
187 * FIXME: need a reload method to be called from a resume
188 *---------------------------------------------------------------*/
189/*
190 * Magic for persistent mirrors: "MiRr"
191 */
192#define MIRROR_MAGIC 0x4D695272
193
194/*
195 * The on-disk version of the metadata.
196 */
197#define MIRROR_DISK_VERSION 2
198#define LOG_OFFSET 2
199
200struct log_header_disk {
201 __le32 magic;
202
203 /*
204 * Simple, incrementing version. no backward
205 * compatibility.
206 */
207 __le32 version;
208 __le64 nr_regions;
209} __packed;
210
211struct log_header_core {
212 uint32_t magic;
213 uint32_t version;
214 uint64_t nr_regions;
215};
216
217struct log_c {
218 struct dm_target *ti;
219 int touched_dirtied;
220 int touched_cleaned;
221 int flush_failed;
222 uint32_t region_size;
223 unsigned int region_count;
224 region_t sync_count;
225
226 unsigned bitset_uint32_count;
227 uint32_t *clean_bits;
228 uint32_t *sync_bits;
229 uint32_t *recovering_bits; /* FIXME: this seems excessive */
230
231 int sync_search;
232
233 /* Resync flag */
234 enum sync {
235 DEFAULTSYNC, /* Synchronize if necessary */
236 NOSYNC, /* Devices known to be already in sync */
237 FORCESYNC, /* Force a sync to happen */
238 } sync;
239
240 struct dm_io_request io_req;
241
242 /*
243 * Disk log fields
244 */
245 int log_dev_failed;
246 int log_dev_flush_failed;
247 struct dm_dev *log_dev;
248 struct log_header_core header;
249
250 struct dm_io_region header_location;
251 struct log_header_disk *disk_header;
252};
253
254/*
255 * The touched member needs to be updated every time we access
256 * one of the bitsets.
257 */
258static inline int log_test_bit(uint32_t *bs, unsigned bit)
259{
260 return test_bit_le(bit, bs) ? 1 : 0;
261}
262
263static inline void log_set_bit(struct log_c *l,
264 uint32_t *bs, unsigned bit)
265{
266 __set_bit_le(bit, bs);
267 l->touched_cleaned = 1;
268}
269
270static inline void log_clear_bit(struct log_c *l,
271 uint32_t *bs, unsigned bit)
272{
273 __clear_bit_le(bit, bs);
274 l->touched_dirtied = 1;
275}
276
277/*----------------------------------------------------------------
278 * Header IO
279 *--------------------------------------------------------------*/
280static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
281{
282 disk->magic = cpu_to_le32(core->magic);
283 disk->version = cpu_to_le32(core->version);
284 disk->nr_regions = cpu_to_le64(core->nr_regions);
285}
286
287static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
288{
289 core->magic = le32_to_cpu(disk->magic);
290 core->version = le32_to_cpu(disk->version);
291 core->nr_regions = le64_to_cpu(disk->nr_regions);
292}
293
294static int rw_header(struct log_c *lc, enum req_op op)
295{
296 lc->io_req.bi_opf = op;
297
298 return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
299}
300
301static int flush_header(struct log_c *lc)
302{
303 struct dm_io_region null_location = {
304 .bdev = lc->header_location.bdev,
305 .sector = 0,
306 .count = 0,
307 };
308
309 lc->io_req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
310
311 return dm_io(&lc->io_req, 1, &null_location, NULL);
312}
313
314static int read_header(struct log_c *log)
315{
316 int r;
317
318 r = rw_header(log, REQ_OP_READ);
319 if (r)
320 return r;
321
322 header_from_disk(&log->header, log->disk_header);
323
324 /* New log required? */
325 if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
326 log->header.magic = MIRROR_MAGIC;
327 log->header.version = MIRROR_DISK_VERSION;
328 log->header.nr_regions = 0;
329 }
330
331#ifdef __LITTLE_ENDIAN
332 if (log->header.version == 1)
333 log->header.version = 2;
334#endif
335
336 if (log->header.version != MIRROR_DISK_VERSION) {
337 DMWARN("incompatible disk log version");
338 return -EINVAL;
339 }
340
341 return 0;
342}
343
344static int _check_region_size(struct dm_target *ti, uint32_t region_size)
345{
346 if (region_size < 2 || region_size > ti->len)
347 return 0;
348
349 if (!is_power_of_2(region_size))
350 return 0;
351
352 return 1;
353}
354
355/*----------------------------------------------------------------
356 * core log constructor/destructor
357 *
358 * argv contains region_size followed optionally by [no]sync
359 *--------------------------------------------------------------*/
360#define BYTE_SHIFT 3
361static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
362 unsigned int argc, char **argv,
363 struct dm_dev *dev)
364{
365 enum sync sync = DEFAULTSYNC;
366
367 struct log_c *lc;
368 uint32_t region_size;
369 unsigned int region_count;
370 size_t bitset_size, buf_size;
371 int r;
372 char dummy;
373
374 if (argc < 1 || argc > 2) {
375 DMWARN("wrong number of arguments to dirty region log");
376 return -EINVAL;
377 }
378
379 if (argc > 1) {
380 if (!strcmp(argv[1], "sync"))
381 sync = FORCESYNC;
382 else if (!strcmp(argv[1], "nosync"))
383 sync = NOSYNC;
384 else {
385 DMWARN("unrecognised sync argument to "
386 "dirty region log: %s", argv[1]);
387 return -EINVAL;
388 }
389 }
390
391 if (sscanf(argv[0], "%u%c", ®ion_size, &dummy) != 1 ||
392 !_check_region_size(ti, region_size)) {
393 DMWARN("invalid region size %s", argv[0]);
394 return -EINVAL;
395 }
396
397 region_count = dm_sector_div_up(ti->len, region_size);
398
399 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
400 if (!lc) {
401 DMWARN("couldn't allocate core log");
402 return -ENOMEM;
403 }
404
405 lc->ti = ti;
406 lc->touched_dirtied = 0;
407 lc->touched_cleaned = 0;
408 lc->flush_failed = 0;
409 lc->region_size = region_size;
410 lc->region_count = region_count;
411 lc->sync = sync;
412
413 /*
414 * Work out how many "unsigned long"s we need to hold the bitset.
415 */
416 bitset_size = dm_round_up(region_count, BITS_PER_LONG);
417 bitset_size >>= BYTE_SHIFT;
418
419 lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
420
421 /*
422 * Disk log?
423 */
424 if (!dev) {
425 lc->clean_bits = vmalloc(bitset_size);
426 if (!lc->clean_bits) {
427 DMWARN("couldn't allocate clean bitset");
428 kfree(lc);
429 return -ENOMEM;
430 }
431 lc->disk_header = NULL;
432 } else {
433 lc->log_dev = dev;
434 lc->log_dev_failed = 0;
435 lc->log_dev_flush_failed = 0;
436 lc->header_location.bdev = lc->log_dev->bdev;
437 lc->header_location.sector = 0;
438
439 /*
440 * Buffer holds both header and bitset.
441 */
442 buf_size =
443 dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
444 bdev_logical_block_size(lc->header_location.
445 bdev));
446
447 if (buf_size > bdev_nr_bytes(dev->bdev)) {
448 DMWARN("log device %s too small: need %llu bytes",
449 dev->name, (unsigned long long)buf_size);
450 kfree(lc);
451 return -EINVAL;
452 }
453
454 lc->header_location.count = buf_size >> SECTOR_SHIFT;
455
456 lc->io_req.mem.type = DM_IO_VMA;
457 lc->io_req.notify.fn = NULL;
458 lc->io_req.client = dm_io_client_create();
459 if (IS_ERR(lc->io_req.client)) {
460 r = PTR_ERR(lc->io_req.client);
461 DMWARN("couldn't allocate disk io client");
462 kfree(lc);
463 return r;
464 }
465
466 lc->disk_header = vmalloc(buf_size);
467 if (!lc->disk_header) {
468 DMWARN("couldn't allocate disk log buffer");
469 dm_io_client_destroy(lc->io_req.client);
470 kfree(lc);
471 return -ENOMEM;
472 }
473
474 lc->io_req.mem.ptr.vma = lc->disk_header;
475 lc->clean_bits = (void *)lc->disk_header +
476 (LOG_OFFSET << SECTOR_SHIFT);
477 }
478
479 memset(lc->clean_bits, -1, bitset_size);
480
481 lc->sync_bits = vmalloc(bitset_size);
482 if (!lc->sync_bits) {
483 DMWARN("couldn't allocate sync bitset");
484 if (!dev)
485 vfree(lc->clean_bits);
486 else
487 dm_io_client_destroy(lc->io_req.client);
488 vfree(lc->disk_header);
489 kfree(lc);
490 return -ENOMEM;
491 }
492 memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
493 lc->sync_count = (sync == NOSYNC) ? region_count : 0;
494
495 lc->recovering_bits = vzalloc(bitset_size);
496 if (!lc->recovering_bits) {
497 DMWARN("couldn't allocate sync bitset");
498 vfree(lc->sync_bits);
499 if (!dev)
500 vfree(lc->clean_bits);
501 else
502 dm_io_client_destroy(lc->io_req.client);
503 vfree(lc->disk_header);
504 kfree(lc);
505 return -ENOMEM;
506 }
507 lc->sync_search = 0;
508 log->context = lc;
509
510 return 0;
511}
512
513static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
514 unsigned int argc, char **argv)
515{
516 return create_log_context(log, ti, argc, argv, NULL);
517}
518
519static void destroy_log_context(struct log_c *lc)
520{
521 vfree(lc->sync_bits);
522 vfree(lc->recovering_bits);
523 kfree(lc);
524}
525
526static void core_dtr(struct dm_dirty_log *log)
527{
528 struct log_c *lc = (struct log_c *) log->context;
529
530 vfree(lc->clean_bits);
531 destroy_log_context(lc);
532}
533
534/*----------------------------------------------------------------
535 * disk log constructor/destructor
536 *
537 * argv contains log_device region_size followed optionally by [no]sync
538 *--------------------------------------------------------------*/
539static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
540 unsigned int argc, char **argv)
541{
542 int r;
543 struct dm_dev *dev;
544
545 if (argc < 2 || argc > 3) {
546 DMWARN("wrong number of arguments to disk dirty region log");
547 return -EINVAL;
548 }
549
550 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
551 if (r)
552 return r;
553
554 r = create_log_context(log, ti, argc - 1, argv + 1, dev);
555 if (r) {
556 dm_put_device(ti, dev);
557 return r;
558 }
559
560 return 0;
561}
562
563static void disk_dtr(struct dm_dirty_log *log)
564{
565 struct log_c *lc = (struct log_c *) log->context;
566
567 dm_put_device(lc->ti, lc->log_dev);
568 vfree(lc->disk_header);
569 dm_io_client_destroy(lc->io_req.client);
570 destroy_log_context(lc);
571}
572
573static void fail_log_device(struct log_c *lc)
574{
575 if (lc->log_dev_failed)
576 return;
577
578 lc->log_dev_failed = 1;
579 dm_table_event(lc->ti->table);
580}
581
582static int disk_resume(struct dm_dirty_log *log)
583{
584 int r;
585 unsigned i;
586 struct log_c *lc = (struct log_c *) log->context;
587 size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
588
589 /* read the disk header */
590 r = read_header(lc);
591 if (r) {
592 DMWARN("%s: Failed to read header on dirty region log device",
593 lc->log_dev->name);
594 fail_log_device(lc);
595 /*
596 * If the log device cannot be read, we must assume
597 * all regions are out-of-sync. If we simply return
598 * here, the state will be uninitialized and could
599 * lead us to return 'in-sync' status for regions
600 * that are actually 'out-of-sync'.
601 */
602 lc->header.nr_regions = 0;
603 }
604
605 /* set or clear any new bits -- device has grown */
606 if (lc->sync == NOSYNC)
607 for (i = lc->header.nr_regions; i < lc->region_count; i++)
608 /* FIXME: amazingly inefficient */
609 log_set_bit(lc, lc->clean_bits, i);
610 else
611 for (i = lc->header.nr_regions; i < lc->region_count; i++)
612 /* FIXME: amazingly inefficient */
613 log_clear_bit(lc, lc->clean_bits, i);
614
615 /* clear any old bits -- device has shrunk */
616 for (i = lc->region_count; i % BITS_PER_LONG; i++)
617 log_clear_bit(lc, lc->clean_bits, i);
618
619 /* copy clean across to sync */
620 memcpy(lc->sync_bits, lc->clean_bits, size);
621 lc->sync_count = memweight(lc->clean_bits,
622 lc->bitset_uint32_count * sizeof(uint32_t));
623 lc->sync_search = 0;
624
625 /* set the correct number of regions in the header */
626 lc->header.nr_regions = lc->region_count;
627
628 header_to_disk(&lc->header, lc->disk_header);
629
630 /* write the new header */
631 r = rw_header(lc, REQ_OP_WRITE);
632 if (!r) {
633 r = flush_header(lc);
634 if (r)
635 lc->log_dev_flush_failed = 1;
636 }
637 if (r) {
638 DMWARN("%s: Failed to write header on dirty region log device",
639 lc->log_dev->name);
640 fail_log_device(lc);
641 }
642
643 return r;
644}
645
646static uint32_t core_get_region_size(struct dm_dirty_log *log)
647{
648 struct log_c *lc = (struct log_c *) log->context;
649 return lc->region_size;
650}
651
652static int core_resume(struct dm_dirty_log *log)
653{
654 struct log_c *lc = (struct log_c *) log->context;
655 lc->sync_search = 0;
656 return 0;
657}
658
659static int core_is_clean(struct dm_dirty_log *log, region_t region)
660{
661 struct log_c *lc = (struct log_c *) log->context;
662 return log_test_bit(lc->clean_bits, region);
663}
664
665static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
666{
667 struct log_c *lc = (struct log_c *) log->context;
668 return log_test_bit(lc->sync_bits, region);
669}
670
671static int core_flush(struct dm_dirty_log *log)
672{
673 /* no op */
674 return 0;
675}
676
677static int disk_flush(struct dm_dirty_log *log)
678{
679 int r, i;
680 struct log_c *lc = log->context;
681
682 /* only write if the log has changed */
683 if (!lc->touched_cleaned && !lc->touched_dirtied)
684 return 0;
685
686 if (lc->touched_cleaned && log->flush_callback_fn &&
687 log->flush_callback_fn(lc->ti)) {
688 /*
689 * At this point it is impossible to determine which
690 * regions are clean and which are dirty (without
691 * re-reading the log off disk). So mark all of them
692 * dirty.
693 */
694 lc->flush_failed = 1;
695 for (i = 0; i < lc->region_count; i++)
696 log_clear_bit(lc, lc->clean_bits, i);
697 }
698
699 r = rw_header(lc, REQ_OP_WRITE);
700 if (r)
701 fail_log_device(lc);
702 else {
703 if (lc->touched_dirtied) {
704 r = flush_header(lc);
705 if (r) {
706 lc->log_dev_flush_failed = 1;
707 fail_log_device(lc);
708 } else
709 lc->touched_dirtied = 0;
710 }
711 lc->touched_cleaned = 0;
712 }
713
714 return r;
715}
716
717static void core_mark_region(struct dm_dirty_log *log, region_t region)
718{
719 struct log_c *lc = (struct log_c *) log->context;
720 log_clear_bit(lc, lc->clean_bits, region);
721}
722
723static void core_clear_region(struct dm_dirty_log *log, region_t region)
724{
725 struct log_c *lc = (struct log_c *) log->context;
726 if (likely(!lc->flush_failed))
727 log_set_bit(lc, lc->clean_bits, region);
728}
729
730static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
731{
732 struct log_c *lc = (struct log_c *) log->context;
733
734 if (lc->sync_search >= lc->region_count)
735 return 0;
736
737 do {
738 *region = find_next_zero_bit_le(lc->sync_bits,
739 lc->region_count,
740 lc->sync_search);
741 lc->sync_search = *region + 1;
742
743 if (*region >= lc->region_count)
744 return 0;
745
746 } while (log_test_bit(lc->recovering_bits, *region));
747
748 log_set_bit(lc, lc->recovering_bits, *region);
749 return 1;
750}
751
752static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
753 int in_sync)
754{
755 struct log_c *lc = (struct log_c *) log->context;
756
757 log_clear_bit(lc, lc->recovering_bits, region);
758 if (in_sync) {
759 log_set_bit(lc, lc->sync_bits, region);
760 lc->sync_count++;
761 } else if (log_test_bit(lc->sync_bits, region)) {
762 lc->sync_count--;
763 log_clear_bit(lc, lc->sync_bits, region);
764 }
765}
766
767static region_t core_get_sync_count(struct dm_dirty_log *log)
768{
769 struct log_c *lc = (struct log_c *) log->context;
770
771 return lc->sync_count;
772}
773
774#define DMEMIT_SYNC \
775 if (lc->sync != DEFAULTSYNC) \
776 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
777
778static int core_status(struct dm_dirty_log *log, status_type_t status,
779 char *result, unsigned int maxlen)
780{
781 int sz = 0;
782 struct log_c *lc = log->context;
783
784 switch(status) {
785 case STATUSTYPE_INFO:
786 DMEMIT("1 %s", log->type->name);
787 break;
788
789 case STATUSTYPE_TABLE:
790 DMEMIT("%s %u %u ", log->type->name,
791 lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
792 DMEMIT_SYNC;
793 break;
794
795 case STATUSTYPE_IMA:
796 *result = '\0';
797 break;
798 }
799
800 return sz;
801}
802
803static int disk_status(struct dm_dirty_log *log, status_type_t status,
804 char *result, unsigned int maxlen)
805{
806 int sz = 0;
807 struct log_c *lc = log->context;
808
809 switch(status) {
810 case STATUSTYPE_INFO:
811 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
812 lc->log_dev_flush_failed ? 'F' :
813 lc->log_dev_failed ? 'D' :
814 'A');
815 break;
816
817 case STATUSTYPE_TABLE:
818 DMEMIT("%s %u %s %u ", log->type->name,
819 lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
820 lc->region_size);
821 DMEMIT_SYNC;
822 break;
823
824 case STATUSTYPE_IMA:
825 *result = '\0';
826 break;
827 }
828
829 return sz;
830}
831
832static struct dm_dirty_log_type _core_type = {
833 .name = "core",
834 .module = THIS_MODULE,
835 .ctr = core_ctr,
836 .dtr = core_dtr,
837 .resume = core_resume,
838 .get_region_size = core_get_region_size,
839 .is_clean = core_is_clean,
840 .in_sync = core_in_sync,
841 .flush = core_flush,
842 .mark_region = core_mark_region,
843 .clear_region = core_clear_region,
844 .get_resync_work = core_get_resync_work,
845 .set_region_sync = core_set_region_sync,
846 .get_sync_count = core_get_sync_count,
847 .status = core_status,
848};
849
850static struct dm_dirty_log_type _disk_type = {
851 .name = "disk",
852 .module = THIS_MODULE,
853 .ctr = disk_ctr,
854 .dtr = disk_dtr,
855 .postsuspend = disk_flush,
856 .resume = disk_resume,
857 .get_region_size = core_get_region_size,
858 .is_clean = core_is_clean,
859 .in_sync = core_in_sync,
860 .flush = disk_flush,
861 .mark_region = core_mark_region,
862 .clear_region = core_clear_region,
863 .get_resync_work = core_get_resync_work,
864 .set_region_sync = core_set_region_sync,
865 .get_sync_count = core_get_sync_count,
866 .status = disk_status,
867};
868
869static int __init dm_dirty_log_init(void)
870{
871 int r;
872
873 r = dm_dirty_log_type_register(&_core_type);
874 if (r)
875 DMWARN("couldn't register core log");
876
877 r = dm_dirty_log_type_register(&_disk_type);
878 if (r) {
879 DMWARN("couldn't register disk type");
880 dm_dirty_log_type_unregister(&_core_type);
881 }
882
883 return r;
884}
885
886static void __exit dm_dirty_log_exit(void)
887{
888 dm_dirty_log_type_unregister(&_disk_type);
889 dm_dirty_log_type_unregister(&_core_type);
890}
891
892module_init(dm_dirty_log_init);
893module_exit(dm_dirty_log_exit);
894
895MODULE_DESCRIPTION(DM_NAME " dirty region log");
896MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
897MODULE_LICENSE("GPL");