virtio: Add memory statistics reporting to the balloon driver (V4)
[linux-2.6.git] / drivers / md / dm-log.c
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                         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 }
175 EXPORT_SYMBOL(dm_dirty_log_create);
176
177 void dm_dirty_log_destroy(struct dm_dirty_log *log)
178 {
179         log->type->dtr(log);
180         put_type(log->type);
181         kfree(log);
182 }
183 EXPORT_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
200 struct log_header {
201         uint32_t magic;
202
203         /*
204          * Simple, incrementing version. no backward
205          * compatibility.
206          */
207         uint32_t version;
208         sector_t nr_regions;
209 };
210
211 struct log_c {
212         struct dm_target *ti;
213         int touched_dirtied;
214         int touched_cleaned;
215         int flush_failed;
216         uint32_t region_size;
217         unsigned int region_count;
218         region_t sync_count;
219
220         unsigned bitset_uint32_count;
221         uint32_t *clean_bits;
222         uint32_t *sync_bits;
223         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
224
225         int sync_search;
226
227         /* Resync flag */
228         enum sync {
229                 DEFAULTSYNC,    /* Synchronize if necessary */
230                 NOSYNC,         /* Devices known to be already in sync */
231                 FORCESYNC,      /* Force a sync to happen */
232         } sync;
233
234         struct dm_io_request io_req;
235
236         /*
237          * Disk log fields
238          */
239         int log_dev_failed;
240         int log_dev_flush_failed;
241         struct dm_dev *log_dev;
242         struct log_header header;
243
244         struct dm_io_region header_location;
245         struct log_header *disk_header;
246 };
247
248 /*
249  * The touched member needs to be updated every time we access
250  * one of the bitsets.
251  */
252 static inline int log_test_bit(uint32_t *bs, unsigned bit)
253 {
254         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
255 }
256
257 static inline void log_set_bit(struct log_c *l,
258                                uint32_t *bs, unsigned bit)
259 {
260         ext2_set_bit(bit, (unsigned long *) bs);
261         l->touched_cleaned = 1;
262 }
263
264 static inline void log_clear_bit(struct log_c *l,
265                                  uint32_t *bs, unsigned bit)
266 {
267         ext2_clear_bit(bit, (unsigned long *) bs);
268         l->touched_dirtied = 1;
269 }
270
271 /*----------------------------------------------------------------
272  * Header IO
273  *--------------------------------------------------------------*/
274 static void header_to_disk(struct log_header *core, struct log_header *disk)
275 {
276         disk->magic = cpu_to_le32(core->magic);
277         disk->version = cpu_to_le32(core->version);
278         disk->nr_regions = cpu_to_le64(core->nr_regions);
279 }
280
281 static void header_from_disk(struct log_header *core, struct log_header *disk)
282 {
283         core->magic = le32_to_cpu(disk->magic);
284         core->version = le32_to_cpu(disk->version);
285         core->nr_regions = le64_to_cpu(disk->nr_regions);
286 }
287
288 static int rw_header(struct log_c *lc, int rw)
289 {
290         lc->io_req.bi_rw = rw;
291
292         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
293 }
294
295 static int flush_header(struct log_c *lc)
296 {
297         struct dm_io_region null_location = {
298                 .bdev = lc->header_location.bdev,
299                 .sector = 0,
300                 .count = 0,
301         };
302
303         lc->io_req.bi_rw = WRITE_BARRIER;
304
305         return dm_io(&lc->io_req, 1, &null_location, NULL);
306 }
307
308 static int read_header(struct log_c *log)
309 {
310         int r;
311
312         r = rw_header(log, READ);
313         if (r)
314                 return r;
315
316         header_from_disk(&log->header, log->disk_header);
317
318         /* New log required? */
319         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
320                 log->header.magic = MIRROR_MAGIC;
321                 log->header.version = MIRROR_DISK_VERSION;
322                 log->header.nr_regions = 0;
323         }
324
325 #ifdef __LITTLE_ENDIAN
326         if (log->header.version == 1)
327                 log->header.version = 2;
328 #endif
329
330         if (log->header.version != MIRROR_DISK_VERSION) {
331                 DMWARN("incompatible disk log version");
332                 return -EINVAL;
333         }
334
335         return 0;
336 }
337
338 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
339 {
340         if (region_size < 2 || region_size > ti->len)
341                 return 0;
342
343         if (!is_power_of_2(region_size))
344                 return 0;
345
346         return 1;
347 }
348
349 /*----------------------------------------------------------------
350  * core log constructor/destructor
351  *
352  * argv contains region_size followed optionally by [no]sync
353  *--------------------------------------------------------------*/
354 #define BYTE_SHIFT 3
355 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
356                               unsigned int argc, char **argv,
357                               struct dm_dev *dev)
358 {
359         enum sync sync = DEFAULTSYNC;
360
361         struct log_c *lc;
362         uint32_t region_size;
363         unsigned int region_count;
364         size_t bitset_size, buf_size;
365         int r;
366
367         if (argc < 1 || argc > 2) {
368                 DMWARN("wrong number of arguments to dirty region log");
369                 return -EINVAL;
370         }
371
372         if (argc > 1) {
373                 if (!strcmp(argv[1], "sync"))
374                         sync = FORCESYNC;
375                 else if (!strcmp(argv[1], "nosync"))
376                         sync = NOSYNC;
377                 else {
378                         DMWARN("unrecognised sync argument to "
379                                "dirty region log: %s", argv[1]);
380                         return -EINVAL;
381                 }
382         }
383
384         if (sscanf(argv[0], "%u", &region_size) != 1 ||
385             !_check_region_size(ti, region_size)) {
386                 DMWARN("invalid region size %s", argv[0]);
387                 return -EINVAL;
388         }
389
390         region_count = dm_sector_div_up(ti->len, region_size);
391
392         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
393         if (!lc) {
394                 DMWARN("couldn't allocate core log");
395                 return -ENOMEM;
396         }
397
398         lc->ti = ti;
399         lc->touched_dirtied = 0;
400         lc->touched_cleaned = 0;
401         lc->flush_failed = 0;
402         lc->region_size = region_size;
403         lc->region_count = region_count;
404         lc->sync = sync;
405
406         /*
407          * Work out how many "unsigned long"s we need to hold the bitset.
408          */
409         bitset_size = dm_round_up(region_count,
410                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
411         bitset_size >>= BYTE_SHIFT;
412
413         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
414
415         /*
416          * Disk log?
417          */
418         if (!dev) {
419                 lc->clean_bits = vmalloc(bitset_size);
420                 if (!lc->clean_bits) {
421                         DMWARN("couldn't allocate clean bitset");
422                         kfree(lc);
423                         return -ENOMEM;
424                 }
425                 lc->disk_header = NULL;
426         } else {
427                 lc->log_dev = dev;
428                 lc->log_dev_failed = 0;
429                 lc->log_dev_flush_failed = 0;
430                 lc->header_location.bdev = lc->log_dev->bdev;
431                 lc->header_location.sector = 0;
432
433                 /*
434                  * Buffer holds both header and bitset.
435                  */
436                 buf_size =
437                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
438                                 bdev_logical_block_size(lc->header_location.
439                                                             bdev));
440
441                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
442                         DMWARN("log device %s too small: need %llu bytes",
443                                 dev->name, (unsigned long long)buf_size);
444                         kfree(lc);
445                         return -EINVAL;
446                 }
447
448                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
449
450                 lc->io_req.mem.type = DM_IO_VMA;
451                 lc->io_req.notify.fn = NULL;
452                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
453                                                                    PAGE_SIZE));
454                 if (IS_ERR(lc->io_req.client)) {
455                         r = PTR_ERR(lc->io_req.client);
456                         DMWARN("couldn't allocate disk io client");
457                         kfree(lc);
458                         return -ENOMEM;
459                 }
460
461                 lc->disk_header = vmalloc(buf_size);
462                 if (!lc->disk_header) {
463                         DMWARN("couldn't allocate disk log buffer");
464                         dm_io_client_destroy(lc->io_req.client);
465                         kfree(lc);
466                         return -ENOMEM;
467                 }
468
469                 lc->io_req.mem.ptr.vma = lc->disk_header;
470                 lc->clean_bits = (void *)lc->disk_header +
471                                  (LOG_OFFSET << SECTOR_SHIFT);
472         }
473
474         memset(lc->clean_bits, -1, bitset_size);
475
476         lc->sync_bits = vmalloc(bitset_size);
477         if (!lc->sync_bits) {
478                 DMWARN("couldn't allocate sync bitset");
479                 if (!dev)
480                         vfree(lc->clean_bits);
481                 else
482                         dm_io_client_destroy(lc->io_req.client);
483                 vfree(lc->disk_header);
484                 kfree(lc);
485                 return -ENOMEM;
486         }
487         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
488         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
489
490         lc->recovering_bits = vmalloc(bitset_size);
491         if (!lc->recovering_bits) {
492                 DMWARN("couldn't allocate sync bitset");
493                 vfree(lc->sync_bits);
494                 if (!dev)
495                         vfree(lc->clean_bits);
496                 else
497                         dm_io_client_destroy(lc->io_req.client);
498                 vfree(lc->disk_header);
499                 kfree(lc);
500                 return -ENOMEM;
501         }
502         memset(lc->recovering_bits, 0, bitset_size);
503         lc->sync_search = 0;
504         log->context = lc;
505
506         return 0;
507 }
508
509 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
510                     unsigned int argc, char **argv)
511 {
512         return create_log_context(log, ti, argc, argv, NULL);
513 }
514
515 static void destroy_log_context(struct log_c *lc)
516 {
517         vfree(lc->sync_bits);
518         vfree(lc->recovering_bits);
519         kfree(lc);
520 }
521
522 static void core_dtr(struct dm_dirty_log *log)
523 {
524         struct log_c *lc = (struct log_c *) log->context;
525
526         vfree(lc->clean_bits);
527         destroy_log_context(lc);
528 }
529
530 /*----------------------------------------------------------------
531  * disk log constructor/destructor
532  *
533  * argv contains log_device region_size followed optionally by [no]sync
534  *--------------------------------------------------------------*/
535 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
536                     unsigned int argc, char **argv)
537 {
538         int r;
539         struct dm_dev *dev;
540
541         if (argc < 2 || argc > 3) {
542                 DMWARN("wrong number of arguments to disk dirty region log");
543                 return -EINVAL;
544         }
545
546         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
547                           FMODE_READ | FMODE_WRITE, &dev);
548         if (r)
549                 return r;
550
551         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
552         if (r) {
553                 dm_put_device(ti, dev);
554                 return r;
555         }
556
557         return 0;
558 }
559
560 static void disk_dtr(struct dm_dirty_log *log)
561 {
562         struct log_c *lc = (struct log_c *) log->context;
563
564         dm_put_device(lc->ti, lc->log_dev);
565         vfree(lc->disk_header);
566         dm_io_client_destroy(lc->io_req.client);
567         destroy_log_context(lc);
568 }
569
570 static int count_bits32(uint32_t *addr, unsigned size)
571 {
572         int count = 0, i;
573
574         for (i = 0; i < size; i++) {
575                 count += hweight32(*(addr+i));
576         }
577         return count;
578 }
579
580 static 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
589 static int disk_resume(struct dm_dirty_log *log)
590 {
591         int r;
592         unsigned i;
593         struct log_c *lc = (struct log_c *) 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 % (sizeof(*lc->clean_bits) << BYTE_SHIFT); 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 = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
629         lc->sync_search = 0;
630
631         /* set the correct number of regions in the header */
632         lc->header.nr_regions = lc->region_count;
633
634         header_to_disk(&lc->header, lc->disk_header);
635
636         /* write the new header */
637         r = rw_header(lc, WRITE);
638         if (!r) {
639                 r = flush_header(lc);
640                 if (r)
641                         lc->log_dev_flush_failed = 1;
642         }
643         if (r) {
644                 DMWARN("%s: Failed to write header on dirty region log device",
645                        lc->log_dev->name);
646                 fail_log_device(lc);
647         }
648
649         return r;
650 }
651
652 static uint32_t core_get_region_size(struct dm_dirty_log *log)
653 {
654         struct log_c *lc = (struct log_c *) log->context;
655         return lc->region_size;
656 }
657
658 static int core_resume(struct dm_dirty_log *log)
659 {
660         struct log_c *lc = (struct log_c *) log->context;
661         lc->sync_search = 0;
662         return 0;
663 }
664
665 static int core_is_clean(struct dm_dirty_log *log, region_t region)
666 {
667         struct log_c *lc = (struct log_c *) log->context;
668         return log_test_bit(lc->clean_bits, region);
669 }
670
671 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
672 {
673         struct log_c *lc = (struct log_c *) log->context;
674         return log_test_bit(lc->sync_bits, region);
675 }
676
677 static int core_flush(struct dm_dirty_log *log)
678 {
679         /* no op */
680         return 0;
681 }
682
683 static int disk_flush(struct dm_dirty_log *log)
684 {
685         int r, i;
686         struct log_c *lc = log->context;
687
688         /* only write if the log has changed */
689         if (!lc->touched_cleaned && !lc->touched_dirtied)
690                 return 0;
691
692         if (lc->touched_cleaned && log->flush_callback_fn &&
693             log->flush_callback_fn(lc->ti)) {
694                 /*
695                  * At this point it is impossible to determine which
696                  * regions are clean and which are dirty (without
697                  * re-reading the log off disk). So mark all of them
698                  * dirty.
699                  */
700                 lc->flush_failed = 1;
701                 for (i = 0; i < lc->region_count; i++)
702                         log_clear_bit(lc, lc->clean_bits, i);
703         }
704
705         r = rw_header(lc, WRITE);
706         if (r)
707                 fail_log_device(lc);
708         else {
709                 if (lc->touched_dirtied) {
710                         r = flush_header(lc);
711                         if (r) {
712                                 lc->log_dev_flush_failed = 1;
713                                 fail_log_device(lc);
714                         } else
715                                 lc->touched_dirtied = 0;
716                 }
717                 lc->touched_cleaned = 0;
718         }
719
720         return r;
721 }
722
723 static void core_mark_region(struct dm_dirty_log *log, region_t region)
724 {
725         struct log_c *lc = (struct log_c *) log->context;
726         log_clear_bit(lc, lc->clean_bits, region);
727 }
728
729 static void core_clear_region(struct dm_dirty_log *log, region_t region)
730 {
731         struct log_c *lc = (struct log_c *) log->context;
732         if (likely(!lc->flush_failed))
733                 log_set_bit(lc, lc->clean_bits, region);
734 }
735
736 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
737 {
738         struct log_c *lc = (struct log_c *) log->context;
739
740         if (lc->sync_search >= lc->region_count)
741                 return 0;
742
743         do {
744                 *region = ext2_find_next_zero_bit(
745                                              (unsigned long *) lc->sync_bits,
746                                              lc->region_count,
747                                              lc->sync_search);
748                 lc->sync_search = *region + 1;
749
750                 if (*region >= lc->region_count)
751                         return 0;
752
753         } while (log_test_bit(lc->recovering_bits, *region));
754
755         log_set_bit(lc, lc->recovering_bits, *region);
756         return 1;
757 }
758
759 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
760                                  int in_sync)
761 {
762         struct log_c *lc = (struct log_c *) log->context;
763
764         log_clear_bit(lc, lc->recovering_bits, region);
765         if (in_sync) {
766                 log_set_bit(lc, lc->sync_bits, region);
767                 lc->sync_count++;
768         } else if (log_test_bit(lc->sync_bits, region)) {
769                 lc->sync_count--;
770                 log_clear_bit(lc, lc->sync_bits, region);
771         }
772 }
773
774 static region_t core_get_sync_count(struct dm_dirty_log *log)
775 {
776         struct log_c *lc = (struct log_c *) log->context;
777
778         return lc->sync_count;
779 }
780
781 #define DMEMIT_SYNC \
782         if (lc->sync != DEFAULTSYNC) \
783                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
784
785 static int core_status(struct dm_dirty_log *log, status_type_t status,
786                        char *result, unsigned int maxlen)
787 {
788         int sz = 0;
789         struct log_c *lc = log->context;
790
791         switch(status) {
792         case STATUSTYPE_INFO:
793                 DMEMIT("1 %s", log->type->name);
794                 break;
795
796         case STATUSTYPE_TABLE:
797                 DMEMIT("%s %u %u ", log->type->name,
798                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
799                 DMEMIT_SYNC;
800         }
801
802         return sz;
803 }
804
805 static int disk_status(struct dm_dirty_log *log, status_type_t status,
806                        char *result, unsigned int maxlen)
807 {
808         int sz = 0;
809         struct log_c *lc = log->context;
810
811         switch(status) {
812         case STATUSTYPE_INFO:
813                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
814                        lc->log_dev_flush_failed ? 'F' :
815                        lc->log_dev_failed ? 'D' :
816                        'A');
817                 break;
818
819         case STATUSTYPE_TABLE:
820                 DMEMIT("%s %u %s %u ", log->type->name,
821                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
822                        lc->region_size);
823                 DMEMIT_SYNC;
824         }
825
826         return sz;
827 }
828
829 static struct dm_dirty_log_type _core_type = {
830         .name = "core",
831         .module = THIS_MODULE,
832         .ctr = core_ctr,
833         .dtr = core_dtr,
834         .resume = core_resume,
835         .get_region_size = core_get_region_size,
836         .is_clean = core_is_clean,
837         .in_sync = core_in_sync,
838         .flush = core_flush,
839         .mark_region = core_mark_region,
840         .clear_region = core_clear_region,
841         .get_resync_work = core_get_resync_work,
842         .set_region_sync = core_set_region_sync,
843         .get_sync_count = core_get_sync_count,
844         .status = core_status,
845 };
846
847 static struct dm_dirty_log_type _disk_type = {
848         .name = "disk",
849         .module = THIS_MODULE,
850         .ctr = disk_ctr,
851         .dtr = disk_dtr,
852         .postsuspend = disk_flush,
853         .resume = disk_resume,
854         .get_region_size = core_get_region_size,
855         .is_clean = core_is_clean,
856         .in_sync = core_in_sync,
857         .flush = disk_flush,
858         .mark_region = core_mark_region,
859         .clear_region = core_clear_region,
860         .get_resync_work = core_get_resync_work,
861         .set_region_sync = core_set_region_sync,
862         .get_sync_count = core_get_sync_count,
863         .status = disk_status,
864 };
865
866 static int __init dm_dirty_log_init(void)
867 {
868         int r;
869
870         r = dm_dirty_log_type_register(&_core_type);
871         if (r)
872                 DMWARN("couldn't register core log");
873
874         r = dm_dirty_log_type_register(&_disk_type);
875         if (r) {
876                 DMWARN("couldn't register disk type");
877                 dm_dirty_log_type_unregister(&_core_type);
878         }
879
880         return r;
881 }
882
883 static void __exit dm_dirty_log_exit(void)
884 {
885         dm_dirty_log_type_unregister(&_disk_type);
886         dm_dirty_log_type_unregister(&_core_type);
887 }
888
889 module_init(dm_dirty_log_init);
890 module_exit(dm_dirty_log_exit);
891
892 MODULE_DESCRIPTION(DM_NAME " dirty region log");
893 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
894 MODULE_LICENSE("GPL");