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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2003 Sistina Software
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the LGPL.
7 */
8
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/module.h>
12#include <linux/vmalloc.h>
13#include <linux/dm-io.h>
14#include <linux/dm-dirty-log.h>
15
16#include <linux/device-mapper.h>
17
18#define DM_MSG_PREFIX "dirty region log"
19
20static LIST_HEAD(_log_types);
21static DEFINE_SPINLOCK(_lock);
22
23static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
24{
25 struct dm_dirty_log_type *log_type;
26
27 list_for_each_entry(log_type, &_log_types, list)
28 if (!strcmp(name, log_type->name))
29 return log_type;
30
31 return NULL;
32}
33
34static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
35{
36 struct dm_dirty_log_type *log_type;
37
38 spin_lock(&_lock);
39
40 log_type = __find_dirty_log_type(name);
41 if (log_type && !try_module_get(log_type->module))
42 log_type = NULL;
43
44 spin_unlock(&_lock);
45
46 return log_type;
47}
48
49/*
50 * get_type
51 * @type_name
52 *
53 * Attempt to retrieve the dm_dirty_log_type by name. If not already
54 * available, attempt to load the appropriate module.
55 *
56 * Log modules are named "dm-log-" followed by the 'type_name'.
57 * Modules may contain multiple types.
58 * This function will first try the module "dm-log-<type_name>",
59 * then truncate 'type_name' on the last '-' and try again.
60 *
61 * For example, if type_name was "clustered-disk", it would search
62 * 'dm-log-clustered-disk' then 'dm-log-clustered'.
63 *
64 * Returns: dirty_log_type* on success, NULL on failure
65 */
66static struct dm_dirty_log_type *get_type(const char *type_name)
67{
68 char *p, *type_name_dup;
69 struct dm_dirty_log_type *log_type;
70
71 if (!type_name)
72 return NULL;
73
74 log_type = _get_dirty_log_type(type_name);
75 if (log_type)
76 return log_type;
77
78 type_name_dup = kstrdup(type_name, GFP_KERNEL);
79 if (!type_name_dup) {
80 DMWARN("No memory left to attempt log module load for \"%s\"",
81 type_name);
82 return NULL;
83 }
84
85 while (request_module("dm-log-%s", type_name_dup) ||
86 !(log_type = _get_dirty_log_type(type_name))) {
87 p = strrchr(type_name_dup, '-');
88 if (!p)
89 break;
90 p[0] = '\0';
91 }
92
93 if (!log_type)
94 DMWARN("Module for logging type \"%s\" not found.", type_name);
95
96 kfree(type_name_dup);
97
98 return log_type;
99}
100
101static void put_type(struct dm_dirty_log_type *type)
102{
103 if (!type)
104 return;
105
106 spin_lock(&_lock);
107 if (!__find_dirty_log_type(type->name))
108 goto out;
109
110 module_put(type->module);
111
112out:
113 spin_unlock(&_lock);
114}
115
116int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
117{
118 int r = 0;
119
120 spin_lock(&_lock);
121 if (!__find_dirty_log_type(type->name))
122 list_add(&type->list, &_log_types);
123 else
124 r = -EEXIST;
125 spin_unlock(&_lock);
126
127 return r;
128}
129EXPORT_SYMBOL(dm_dirty_log_type_register);
130
131int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
132{
133 spin_lock(&_lock);
134
135 if (!__find_dirty_log_type(type->name)) {
136 spin_unlock(&_lock);
137 return -EINVAL;
138 }
139
140 list_del(&type->list);
141
142 spin_unlock(&_lock);
143
144 return 0;
145}
146EXPORT_SYMBOL(dm_dirty_log_type_unregister);
147
148struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
149 struct dm_target *ti,
150 int (*flush_callback_fn)(struct dm_target *ti),
151 unsigned int argc, char **argv)
152{
153 struct dm_dirty_log_type *type;
154 struct dm_dirty_log *log;
155
156 log = kmalloc(sizeof(*log), GFP_KERNEL);
157 if (!log)
158 return NULL;
159
160 type = get_type(type_name);
161 if (!type) {
162 kfree(log);
163 return NULL;
164 }
165
166 log->flush_callback_fn = flush_callback_fn;
167 log->type = type;
168 if (type->ctr(log, ti, argc, argv)) {
169 kfree(log);
170 put_type(type);
171 return NULL;
172 }
173
174 return log;
175}
176EXPORT_SYMBOL(dm_dirty_log_create);
177
178void dm_dirty_log_destroy(struct dm_dirty_log *log)
179{
180 log->type->dtr(log);
181 put_type(log->type);
182 kfree(log);
183}
184EXPORT_SYMBOL(dm_dirty_log_destroy);
185
186/*
187 *---------------------------------------------------------------
188 * Persistent and core logs share a lot of their implementation.
189 * FIXME: need a reload method to be called from a resume
190 *---------------------------------------------------------------
191 */
192/*
193 * Magic for persistent mirrors: "MiRr"
194 */
195#define MIRROR_MAGIC 0x4D695272
196
197/*
198 * The on-disk version of the metadata.
199 */
200#define MIRROR_DISK_VERSION 2
201#define LOG_OFFSET 2
202
203struct log_header_disk {
204 __le32 magic;
205
206 /*
207 * Simple, incrementing version. no backward
208 * compatibility.
209 */
210 __le32 version;
211 __le64 nr_regions;
212} __packed;
213
214struct log_header_core {
215 uint32_t magic;
216 uint32_t version;
217 uint64_t nr_regions;
218};
219
220struct log_c {
221 struct dm_target *ti;
222 int touched_dirtied;
223 int touched_cleaned;
224 int flush_failed;
225 uint32_t region_size;
226 unsigned int region_count;
227 region_t sync_count;
228
229 unsigned int bitset_uint32_count;
230 uint32_t *clean_bits;
231 uint32_t *sync_bits;
232 uint32_t *recovering_bits; /* FIXME: this seems excessive */
233
234 int sync_search;
235
236 /* Resync flag */
237 enum sync {
238 DEFAULTSYNC, /* Synchronize if necessary */
239 NOSYNC, /* Devices known to be already in sync */
240 FORCESYNC, /* Force a sync to happen */
241 } sync;
242
243 struct dm_io_request io_req;
244
245 /*
246 * Disk log fields
247 */
248 int log_dev_failed;
249 int log_dev_flush_failed;
250 struct dm_dev *log_dev;
251 struct log_header_core header;
252
253 struct dm_io_region header_location;
254 struct log_header_disk *disk_header;
255};
256
257/*
258 * The touched member needs to be updated every time we access
259 * one of the bitsets.
260 */
261static inline int log_test_bit(uint32_t *bs, unsigned int bit)
262{
263 return test_bit_le(bit, bs) ? 1 : 0;
264}
265
266static inline void log_set_bit(struct log_c *l,
267 uint32_t *bs, unsigned int bit)
268{
269 __set_bit_le(bit, bs);
270 l->touched_cleaned = 1;
271}
272
273static inline void log_clear_bit(struct log_c *l,
274 uint32_t *bs, unsigned int bit)
275{
276 __clear_bit_le(bit, bs);
277 l->touched_dirtied = 1;
278}
279
280/*
281 *---------------------------------------------------------------
282 * Header IO
283 *--------------------------------------------------------------
284 */
285static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
286{
287 disk->magic = cpu_to_le32(core->magic);
288 disk->version = cpu_to_le32(core->version);
289 disk->nr_regions = cpu_to_le64(core->nr_regions);
290}
291
292static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
293{
294 core->magic = le32_to_cpu(disk->magic);
295 core->version = le32_to_cpu(disk->version);
296 core->nr_regions = le64_to_cpu(disk->nr_regions);
297}
298
299static int rw_header(struct log_c *lc, enum req_op op)
300{
301 lc->io_req.bi_opf = op;
302
303 return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
304}
305
306static int flush_header(struct log_c *lc)
307{
308 struct dm_io_region null_location = {
309 .bdev = lc->header_location.bdev,
310 .sector = 0,
311 .count = 0,
312 };
313
314 lc->io_req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
315
316 return dm_io(&lc->io_req, 1, &null_location, NULL);
317}
318
319static int read_header(struct log_c *log)
320{
321 int r;
322
323 r = rw_header(log, REQ_OP_READ);
324 if (r)
325 return r;
326
327 header_from_disk(&log->header, log->disk_header);
328
329 /* New log required? */
330 if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
331 log->header.magic = MIRROR_MAGIC;
332 log->header.version = MIRROR_DISK_VERSION;
333 log->header.nr_regions = 0;
334 }
335
336#ifdef __LITTLE_ENDIAN
337 if (log->header.version == 1)
338 log->header.version = 2;
339#endif
340
341 if (log->header.version != MIRROR_DISK_VERSION) {
342 DMWARN("incompatible disk log version");
343 return -EINVAL;
344 }
345
346 return 0;
347}
348
349static int _check_region_size(struct dm_target *ti, uint32_t region_size)
350{
351 if (region_size < 2 || region_size > ti->len)
352 return 0;
353
354 if (!is_power_of_2(region_size))
355 return 0;
356
357 return 1;
358}
359
360/*
361 *--------------------------------------------------------------
362 * core log constructor/destructor
363 *
364 * argv contains region_size followed optionally by [no]sync
365 *--------------------------------------------------------------
366 */
367#define BYTE_SHIFT 3
368static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
369 unsigned int argc, char **argv,
370 struct dm_dev *dev)
371{
372 enum sync sync = DEFAULTSYNC;
373
374 struct log_c *lc;
375 uint32_t region_size;
376 unsigned int region_count;
377 size_t bitset_size, buf_size;
378 int r;
379 char dummy;
380
381 if (argc < 1 || argc > 2) {
382 DMWARN("wrong number of arguments to dirty region log");
383 return -EINVAL;
384 }
385
386 if (argc > 1) {
387 if (!strcmp(argv[1], "sync"))
388 sync = FORCESYNC;
389 else if (!strcmp(argv[1], "nosync"))
390 sync = NOSYNC;
391 else {
392 DMWARN("unrecognised sync argument to dirty region log: %s", argv[1]);
393 return -EINVAL;
394 }
395 }
396
397 if (sscanf(argv[0], "%u%c", ®ion_size, &dummy) != 1 ||
398 !_check_region_size(ti, region_size)) {
399 DMWARN("invalid region size %s", argv[0]);
400 return -EINVAL;
401 }
402
403 region_count = dm_sector_div_up(ti->len, region_size);
404
405 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
406 if (!lc) {
407 DMWARN("couldn't allocate core log");
408 return -ENOMEM;
409 }
410
411 lc->ti = ti;
412 lc->touched_dirtied = 0;
413 lc->touched_cleaned = 0;
414 lc->flush_failed = 0;
415 lc->region_size = region_size;
416 lc->region_count = region_count;
417 lc->sync = sync;
418
419 /*
420 * Work out how many "unsigned long"s we need to hold the bitset.
421 */
422 bitset_size = dm_round_up(region_count, BITS_PER_LONG);
423 bitset_size >>= BYTE_SHIFT;
424
425 lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
426
427 /*
428 * Disk log?
429 */
430 if (!dev) {
431 lc->clean_bits = vmalloc(bitset_size);
432 if (!lc->clean_bits) {
433 DMWARN("couldn't allocate clean bitset");
434 kfree(lc);
435 return -ENOMEM;
436 }
437 lc->disk_header = NULL;
438 } else {
439 lc->log_dev = dev;
440 lc->log_dev_failed = 0;
441 lc->log_dev_flush_failed = 0;
442 lc->header_location.bdev = lc->log_dev->bdev;
443 lc->header_location.sector = 0;
444
445 /*
446 * Buffer holds both header and bitset.
447 */
448 buf_size =
449 dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
450 bdev_logical_block_size(lc->header_location.bdev));
451
452 if (buf_size > bdev_nr_bytes(dev->bdev)) {
453 DMWARN("log device %s too small: need %llu bytes",
454 dev->name, (unsigned long long)buf_size);
455 kfree(lc);
456 return -EINVAL;
457 }
458
459 lc->header_location.count = buf_size >> SECTOR_SHIFT;
460
461 lc->io_req.mem.type = DM_IO_VMA;
462 lc->io_req.notify.fn = NULL;
463 lc->io_req.client = dm_io_client_create();
464 if (IS_ERR(lc->io_req.client)) {
465 r = PTR_ERR(lc->io_req.client);
466 DMWARN("couldn't allocate disk io client");
467 kfree(lc);
468 return r;
469 }
470
471 lc->disk_header = vmalloc(buf_size);
472 if (!lc->disk_header) {
473 DMWARN("couldn't allocate disk log buffer");
474 dm_io_client_destroy(lc->io_req.client);
475 kfree(lc);
476 return -ENOMEM;
477 }
478
479 lc->io_req.mem.ptr.vma = lc->disk_header;
480 lc->clean_bits = (void *)lc->disk_header +
481 (LOG_OFFSET << SECTOR_SHIFT);
482 }
483
484 memset(lc->clean_bits, -1, bitset_size);
485
486 lc->sync_bits = vmalloc(bitset_size);
487 if (!lc->sync_bits) {
488 DMWARN("couldn't allocate sync bitset");
489 if (!dev)
490 vfree(lc->clean_bits);
491 else
492 dm_io_client_destroy(lc->io_req.client);
493 vfree(lc->disk_header);
494 kfree(lc);
495 return -ENOMEM;
496 }
497 memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
498 lc->sync_count = (sync == NOSYNC) ? region_count : 0;
499
500 lc->recovering_bits = vzalloc(bitset_size);
501 if (!lc->recovering_bits) {
502 DMWARN("couldn't allocate sync bitset");
503 vfree(lc->sync_bits);
504 if (!dev)
505 vfree(lc->clean_bits);
506 else
507 dm_io_client_destroy(lc->io_req.client);
508 vfree(lc->disk_header);
509 kfree(lc);
510 return -ENOMEM;
511 }
512 lc->sync_search = 0;
513 log->context = lc;
514
515 return 0;
516}
517
518static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
519 unsigned int argc, char **argv)
520{
521 return create_log_context(log, ti, argc, argv, NULL);
522}
523
524static void destroy_log_context(struct log_c *lc)
525{
526 vfree(lc->sync_bits);
527 vfree(lc->recovering_bits);
528 kfree(lc);
529}
530
531static void core_dtr(struct dm_dirty_log *log)
532{
533 struct log_c *lc = log->context;
534
535 vfree(lc->clean_bits);
536 destroy_log_context(lc);
537}
538
539/*
540 *---------------------------------------------------------------------
541 * disk log constructor/destructor
542 *
543 * argv contains log_device region_size followed optionally by [no]sync
544 *---------------------------------------------------------------------
545 */
546static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
547 unsigned int argc, char **argv)
548{
549 int r;
550 struct dm_dev *dev;
551
552 if (argc < 2 || argc > 3) {
553 DMWARN("wrong number of arguments to disk dirty region log");
554 return -EINVAL;
555 }
556
557 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
558 if (r)
559 return r;
560
561 r = create_log_context(log, ti, argc - 1, argv + 1, dev);
562 if (r) {
563 dm_put_device(ti, dev);
564 return r;
565 }
566
567 return 0;
568}
569
570static void disk_dtr(struct dm_dirty_log *log)
571{
572 struct log_c *lc = log->context;
573
574 dm_put_device(lc->ti, lc->log_dev);
575 vfree(lc->disk_header);
576 dm_io_client_destroy(lc->io_req.client);
577 destroy_log_context(lc);
578}
579
580static void fail_log_device(struct log_c *lc)
581{
582 if (lc->log_dev_failed)
583 return;
584
585 lc->log_dev_failed = 1;
586 dm_table_event(lc->ti->table);
587}
588
589static int disk_resume(struct dm_dirty_log *log)
590{
591 int r;
592 unsigned int i;
593 struct log_c *lc = log->context;
594 size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
595
596 /* read the disk header */
597 r = read_header(lc);
598 if (r) {
599 DMWARN("%s: Failed to read header on dirty region log device",
600 lc->log_dev->name);
601 fail_log_device(lc);
602 /*
603 * If the log device cannot be read, we must assume
604 * all regions are out-of-sync. If we simply return
605 * here, the state will be uninitialized and could
606 * lead us to return 'in-sync' status for regions
607 * that are actually 'out-of-sync'.
608 */
609 lc->header.nr_regions = 0;
610 }
611
612 /* set or clear any new bits -- device has grown */
613 if (lc->sync == NOSYNC)
614 for (i = lc->header.nr_regions; i < lc->region_count; i++)
615 /* FIXME: amazingly inefficient */
616 log_set_bit(lc, lc->clean_bits, i);
617 else
618 for (i = lc->header.nr_regions; i < lc->region_count; i++)
619 /* FIXME: amazingly inefficient */
620 log_clear_bit(lc, lc->clean_bits, i);
621
622 /* clear any old bits -- device has shrunk */
623 for (i = lc->region_count; i % BITS_PER_LONG; i++)
624 log_clear_bit(lc, lc->clean_bits, i);
625
626 /* copy clean across to sync */
627 memcpy(lc->sync_bits, lc->clean_bits, size);
628 lc->sync_count = memweight(lc->clean_bits,
629 lc->bitset_uint32_count * sizeof(uint32_t));
630 lc->sync_search = 0;
631
632 /* set the correct number of regions in the header */
633 lc->header.nr_regions = lc->region_count;
634
635 header_to_disk(&lc->header, lc->disk_header);
636
637 /* write the new header */
638 r = rw_header(lc, REQ_OP_WRITE);
639 if (!r) {
640 r = flush_header(lc);
641 if (r)
642 lc->log_dev_flush_failed = 1;
643 }
644 if (r) {
645 DMWARN("%s: Failed to write header on dirty region log device",
646 lc->log_dev->name);
647 fail_log_device(lc);
648 }
649
650 return r;
651}
652
653static uint32_t core_get_region_size(struct dm_dirty_log *log)
654{
655 struct log_c *lc = log->context;
656
657 return lc->region_size;
658}
659
660static int core_resume(struct dm_dirty_log *log)
661{
662 struct log_c *lc = log->context;
663
664 lc->sync_search = 0;
665 return 0;
666}
667
668static int core_is_clean(struct dm_dirty_log *log, region_t region)
669{
670 struct log_c *lc = log->context;
671
672 return log_test_bit(lc->clean_bits, region);
673}
674
675static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
676{
677 struct log_c *lc = log->context;
678
679 return log_test_bit(lc->sync_bits, region);
680}
681
682static int core_flush(struct dm_dirty_log *log)
683{
684 /* no op */
685 return 0;
686}
687
688static int disk_flush(struct dm_dirty_log *log)
689{
690 int r, i;
691 struct log_c *lc = log->context;
692
693 /* only write if the log has changed */
694 if (!lc->touched_cleaned && !lc->touched_dirtied)
695 return 0;
696
697 if (lc->touched_cleaned && log->flush_callback_fn &&
698 log->flush_callback_fn(lc->ti)) {
699 /*
700 * At this point it is impossible to determine which
701 * regions are clean and which are dirty (without
702 * re-reading the log off disk). So mark all of them
703 * dirty.
704 */
705 lc->flush_failed = 1;
706 for (i = 0; i < lc->region_count; i++)
707 log_clear_bit(lc, lc->clean_bits, i);
708 }
709
710 r = rw_header(lc, REQ_OP_WRITE);
711 if (r)
712 fail_log_device(lc);
713 else {
714 if (lc->touched_dirtied) {
715 r = flush_header(lc);
716 if (r) {
717 lc->log_dev_flush_failed = 1;
718 fail_log_device(lc);
719 } else
720 lc->touched_dirtied = 0;
721 }
722 lc->touched_cleaned = 0;
723 }
724
725 return r;
726}
727
728static void core_mark_region(struct dm_dirty_log *log, region_t region)
729{
730 struct log_c *lc = log->context;
731
732 log_clear_bit(lc, lc->clean_bits, region);
733}
734
735static void core_clear_region(struct dm_dirty_log *log, region_t region)
736{
737 struct log_c *lc = log->context;
738
739 if (likely(!lc->flush_failed))
740 log_set_bit(lc, lc->clean_bits, region);
741}
742
743static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
744{
745 struct log_c *lc = log->context;
746
747 if (lc->sync_search >= lc->region_count)
748 return 0;
749
750 do {
751 *region = find_next_zero_bit_le(lc->sync_bits,
752 lc->region_count,
753 lc->sync_search);
754 lc->sync_search = *region + 1;
755
756 if (*region >= lc->region_count)
757 return 0;
758
759 } while (log_test_bit(lc->recovering_bits, *region));
760
761 log_set_bit(lc, lc->recovering_bits, *region);
762 return 1;
763}
764
765static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
766 int in_sync)
767{
768 struct log_c *lc = log->context;
769
770 log_clear_bit(lc, lc->recovering_bits, region);
771 if (in_sync) {
772 log_set_bit(lc, lc->sync_bits, region);
773 lc->sync_count++;
774 } else if (log_test_bit(lc->sync_bits, region)) {
775 lc->sync_count--;
776 log_clear_bit(lc, lc->sync_bits, region);
777 }
778}
779
780static region_t core_get_sync_count(struct dm_dirty_log *log)
781{
782 struct log_c *lc = log->context;
783
784 return lc->sync_count;
785}
786
787#define DMEMIT_SYNC \
788 do { \
789 if (lc->sync != DEFAULTSYNC) \
790 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : ""); \
791 } while (0)
792
793static int core_status(struct dm_dirty_log *log, status_type_t status,
794 char *result, unsigned int maxlen)
795{
796 int sz = 0;
797 struct log_c *lc = log->context;
798
799 switch (status) {
800 case STATUSTYPE_INFO:
801 DMEMIT("1 %s", log->type->name);
802 break;
803
804 case STATUSTYPE_TABLE:
805 DMEMIT("%s %u %u ", log->type->name,
806 lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
807 DMEMIT_SYNC;
808 break;
809
810 case STATUSTYPE_IMA:
811 *result = '\0';
812 break;
813 }
814
815 return sz;
816}
817
818static int disk_status(struct dm_dirty_log *log, status_type_t status,
819 char *result, unsigned int maxlen)
820{
821 int sz = 0;
822 struct log_c *lc = log->context;
823
824 switch (status) {
825 case STATUSTYPE_INFO:
826 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
827 lc->log_dev_flush_failed ? 'F' :
828 lc->log_dev_failed ? 'D' :
829 'A');
830 break;
831
832 case STATUSTYPE_TABLE:
833 DMEMIT("%s %u %s %u ", log->type->name,
834 lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
835 lc->region_size);
836 DMEMIT_SYNC;
837 break;
838
839 case STATUSTYPE_IMA:
840 *result = '\0';
841 break;
842 }
843
844 return sz;
845}
846
847static struct dm_dirty_log_type _core_type = {
848 .name = "core",
849 .module = THIS_MODULE,
850 .ctr = core_ctr,
851 .dtr = core_dtr,
852 .resume = core_resume,
853 .get_region_size = core_get_region_size,
854 .is_clean = core_is_clean,
855 .in_sync = core_in_sync,
856 .flush = core_flush,
857 .mark_region = core_mark_region,
858 .clear_region = core_clear_region,
859 .get_resync_work = core_get_resync_work,
860 .set_region_sync = core_set_region_sync,
861 .get_sync_count = core_get_sync_count,
862 .status = core_status,
863};
864
865static struct dm_dirty_log_type _disk_type = {
866 .name = "disk",
867 .module = THIS_MODULE,
868 .ctr = disk_ctr,
869 .dtr = disk_dtr,
870 .postsuspend = disk_flush,
871 .resume = disk_resume,
872 .get_region_size = core_get_region_size,
873 .is_clean = core_is_clean,
874 .in_sync = core_in_sync,
875 .flush = disk_flush,
876 .mark_region = core_mark_region,
877 .clear_region = core_clear_region,
878 .get_resync_work = core_get_resync_work,
879 .set_region_sync = core_set_region_sync,
880 .get_sync_count = core_get_sync_count,
881 .status = disk_status,
882};
883
884static int __init dm_dirty_log_init(void)
885{
886 int r;
887
888 r = dm_dirty_log_type_register(&_core_type);
889 if (r)
890 DMWARN("couldn't register core log");
891
892 r = dm_dirty_log_type_register(&_disk_type);
893 if (r) {
894 DMWARN("couldn't register disk type");
895 dm_dirty_log_type_unregister(&_core_type);
896 }
897
898 return r;
899}
900
901static void __exit dm_dirty_log_exit(void)
902{
903 dm_dirty_log_type_unregister(&_disk_type);
904 dm_dirty_log_type_unregister(&_core_type);
905}
906
907module_init(dm_dirty_log_init);
908module_exit(dm_dirty_log_exit);
909
910MODULE_DESCRIPTION(DM_NAME " dirty region log");
911MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
912MODULE_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, 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");