]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - drivers/md/dm-log.c
dm log: clean up bit little endian bitops
[~shefty/rdma-dev.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_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
211 struct log_header_core {
212         uint32_t magic;
213         uint32_t version;
214         uint64_t nr_regions;
215 };
216
217 struct 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  */
258 static inline int log_test_bit(uint32_t *bs, unsigned bit)
259 {
260         return test_bit_le(bit, bs) ? 1 : 0;
261 }
262
263 static 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
270 static 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  *--------------------------------------------------------------*/
280 static 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
287 static 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
294 static int rw_header(struct log_c *lc, int rw)
295 {
296         lc->io_req.bi_rw = rw;
297
298         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
299 }
300
301 static 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_rw = WRITE_FLUSH;
310
311         return dm_io(&lc->io_req, 1, &null_location, NULL);
312 }
313
314 static int read_header(struct log_c *log)
315 {
316         int r;
317
318         r = rw_header(log, 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
344 static 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
361 static 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
373         if (argc < 1 || argc > 2) {
374                 DMWARN("wrong number of arguments to dirty region log");
375                 return -EINVAL;
376         }
377
378         if (argc > 1) {
379                 if (!strcmp(argv[1], "sync"))
380                         sync = FORCESYNC;
381                 else if (!strcmp(argv[1], "nosync"))
382                         sync = NOSYNC;
383                 else {
384                         DMWARN("unrecognised sync argument to "
385                                "dirty region log: %s", argv[1]);
386                         return -EINVAL;
387                 }
388         }
389
390         if (sscanf(argv[0], "%u", &region_size) != 1 ||
391             !_check_region_size(ti, region_size)) {
392                 DMWARN("invalid region size %s", argv[0]);
393                 return -EINVAL;
394         }
395
396         region_count = dm_sector_div_up(ti->len, region_size);
397
398         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
399         if (!lc) {
400                 DMWARN("couldn't allocate core log");
401                 return -ENOMEM;
402         }
403
404         lc->ti = ti;
405         lc->touched_dirtied = 0;
406         lc->touched_cleaned = 0;
407         lc->flush_failed = 0;
408         lc->region_size = region_size;
409         lc->region_count = region_count;
410         lc->sync = sync;
411
412         /*
413          * Work out how many "unsigned long"s we need to hold the bitset.
414          */
415         bitset_size = dm_round_up(region_count,
416                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
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 > i_size_read(dev->bdev->bd_inode)) {
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 = vmalloc(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         memset(lc->recovering_bits, 0, bitset_size);
508         lc->sync_search = 0;
509         log->context = lc;
510
511         return 0;
512 }
513
514 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
515                     unsigned int argc, char **argv)
516 {
517         return create_log_context(log, ti, argc, argv, NULL);
518 }
519
520 static void destroy_log_context(struct log_c *lc)
521 {
522         vfree(lc->sync_bits);
523         vfree(lc->recovering_bits);
524         kfree(lc);
525 }
526
527 static void core_dtr(struct dm_dirty_log *log)
528 {
529         struct log_c *lc = (struct log_c *) log->context;
530
531         vfree(lc->clean_bits);
532         destroy_log_context(lc);
533 }
534
535 /*----------------------------------------------------------------
536  * disk log constructor/destructor
537  *
538  * argv contains log_device region_size followed optionally by [no]sync
539  *--------------------------------------------------------------*/
540 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
541                     unsigned int argc, char **argv)
542 {
543         int r;
544         struct dm_dev *dev;
545
546         if (argc < 2 || argc > 3) {
547                 DMWARN("wrong number of arguments to disk dirty region log");
548                 return -EINVAL;
549         }
550
551         r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
552         if (r)
553                 return r;
554
555         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
556         if (r) {
557                 dm_put_device(ti, dev);
558                 return r;
559         }
560
561         return 0;
562 }
563
564 static void disk_dtr(struct dm_dirty_log *log)
565 {
566         struct log_c *lc = (struct log_c *) log->context;
567
568         dm_put_device(lc->ti, lc->log_dev);
569         vfree(lc->disk_header);
570         dm_io_client_destroy(lc->io_req.client);
571         destroy_log_context(lc);
572 }
573
574 static int count_bits32(uint32_t *addr, unsigned size)
575 {
576         int count = 0, i;
577
578         for (i = 0; i < size; i++) {
579                 count += hweight32(*(addr+i));
580         }
581         return count;
582 }
583
584 static void fail_log_device(struct log_c *lc)
585 {
586         if (lc->log_dev_failed)
587                 return;
588
589         lc->log_dev_failed = 1;
590         dm_table_event(lc->ti->table);
591 }
592
593 static int disk_resume(struct dm_dirty_log *log)
594 {
595         int r;
596         unsigned i;
597         struct log_c *lc = (struct log_c *) log->context;
598         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
599
600         /* read the disk header */
601         r = read_header(lc);
602         if (r) {
603                 DMWARN("%s: Failed to read header on dirty region log device",
604                        lc->log_dev->name);
605                 fail_log_device(lc);
606                 /*
607                  * If the log device cannot be read, we must assume
608                  * all regions are out-of-sync.  If we simply return
609                  * here, the state will be uninitialized and could
610                  * lead us to return 'in-sync' status for regions
611                  * that are actually 'out-of-sync'.
612                  */
613                 lc->header.nr_regions = 0;
614         }
615
616         /* set or clear any new bits -- device has grown */
617         if (lc->sync == NOSYNC)
618                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
619                         /* FIXME: amazingly inefficient */
620                         log_set_bit(lc, lc->clean_bits, i);
621         else
622                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
623                         /* FIXME: amazingly inefficient */
624                         log_clear_bit(lc, lc->clean_bits, i);
625
626         /* clear any old bits -- device has shrunk */
627         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
628                 log_clear_bit(lc, lc->clean_bits, i);
629
630         /* copy clean across to sync */
631         memcpy(lc->sync_bits, lc->clean_bits, size);
632         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
633         lc->sync_search = 0;
634
635         /* set the correct number of regions in the header */
636         lc->header.nr_regions = lc->region_count;
637
638         header_to_disk(&lc->header, lc->disk_header);
639
640         /* write the new header */
641         r = rw_header(lc, WRITE);
642         if (!r) {
643                 r = flush_header(lc);
644                 if (r)
645                         lc->log_dev_flush_failed = 1;
646         }
647         if (r) {
648                 DMWARN("%s: Failed to write header on dirty region log device",
649                        lc->log_dev->name);
650                 fail_log_device(lc);
651         }
652
653         return r;
654 }
655
656 static uint32_t core_get_region_size(struct dm_dirty_log *log)
657 {
658         struct log_c *lc = (struct log_c *) log->context;
659         return lc->region_size;
660 }
661
662 static int core_resume(struct dm_dirty_log *log)
663 {
664         struct log_c *lc = (struct log_c *) log->context;
665         lc->sync_search = 0;
666         return 0;
667 }
668
669 static int core_is_clean(struct dm_dirty_log *log, region_t region)
670 {
671         struct log_c *lc = (struct log_c *) log->context;
672         return log_test_bit(lc->clean_bits, region);
673 }
674
675 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
676 {
677         struct log_c *lc = (struct log_c *) log->context;
678         return log_test_bit(lc->sync_bits, region);
679 }
680
681 static int core_flush(struct dm_dirty_log *log)
682 {
683         /* no op */
684         return 0;
685 }
686
687 static int disk_flush(struct dm_dirty_log *log)
688 {
689         int r, i;
690         struct log_c *lc = log->context;
691
692         /* only write if the log has changed */
693         if (!lc->touched_cleaned && !lc->touched_dirtied)
694                 return 0;
695
696         if (lc->touched_cleaned && log->flush_callback_fn &&
697             log->flush_callback_fn(lc->ti)) {
698                 /*
699                  * At this point it is impossible to determine which
700                  * regions are clean and which are dirty (without
701                  * re-reading the log off disk). So mark all of them
702                  * dirty.
703                  */
704                 lc->flush_failed = 1;
705                 for (i = 0; i < lc->region_count; i++)
706                         log_clear_bit(lc, lc->clean_bits, i);
707         }
708
709         r = rw_header(lc, WRITE);
710         if (r)
711                 fail_log_device(lc);
712         else {
713                 if (lc->touched_dirtied) {
714                         r = flush_header(lc);
715                         if (r) {
716                                 lc->log_dev_flush_failed = 1;
717                                 fail_log_device(lc);
718                         } else
719                                 lc->touched_dirtied = 0;
720                 }
721                 lc->touched_cleaned = 0;
722         }
723
724         return r;
725 }
726
727 static void core_mark_region(struct dm_dirty_log *log, region_t region)
728 {
729         struct log_c *lc = (struct log_c *) log->context;
730         log_clear_bit(lc, lc->clean_bits, region);
731 }
732
733 static void core_clear_region(struct dm_dirty_log *log, region_t region)
734 {
735         struct log_c *lc = (struct log_c *) log->context;
736         if (likely(!lc->flush_failed))
737                 log_set_bit(lc, lc->clean_bits, region);
738 }
739
740 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
741 {
742         struct log_c *lc = (struct log_c *) log->context;
743
744         if (lc->sync_search >= lc->region_count)
745                 return 0;
746
747         do {
748                 *region = find_next_zero_bit_le(lc->sync_bits,
749                                              lc->region_count,
750                                              lc->sync_search);
751                 lc->sync_search = *region + 1;
752
753                 if (*region >= lc->region_count)
754                         return 0;
755
756         } while (log_test_bit(lc->recovering_bits, *region));
757
758         log_set_bit(lc, lc->recovering_bits, *region);
759         return 1;
760 }
761
762 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
763                                  int in_sync)
764 {
765         struct log_c *lc = (struct log_c *) log->context;
766
767         log_clear_bit(lc, lc->recovering_bits, region);
768         if (in_sync) {
769                 log_set_bit(lc, lc->sync_bits, region);
770                 lc->sync_count++;
771         } else if (log_test_bit(lc->sync_bits, region)) {
772                 lc->sync_count--;
773                 log_clear_bit(lc, lc->sync_bits, region);
774         }
775 }
776
777 static region_t core_get_sync_count(struct dm_dirty_log *log)
778 {
779         struct log_c *lc = (struct log_c *) log->context;
780
781         return lc->sync_count;
782 }
783
784 #define DMEMIT_SYNC \
785         if (lc->sync != DEFAULTSYNC) \
786                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
787
788 static int core_status(struct dm_dirty_log *log, status_type_t status,
789                        char *result, unsigned int maxlen)
790 {
791         int sz = 0;
792         struct log_c *lc = log->context;
793
794         switch(status) {
795         case STATUSTYPE_INFO:
796                 DMEMIT("1 %s", log->type->name);
797                 break;
798
799         case STATUSTYPE_TABLE:
800                 DMEMIT("%s %u %u ", log->type->name,
801                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
802                 DMEMIT_SYNC;
803         }
804
805         return sz;
806 }
807
808 static int disk_status(struct dm_dirty_log *log, status_type_t status,
809                        char *result, unsigned int maxlen)
810 {
811         int sz = 0;
812         struct log_c *lc = log->context;
813
814         switch(status) {
815         case STATUSTYPE_INFO:
816                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
817                        lc->log_dev_flush_failed ? 'F' :
818                        lc->log_dev_failed ? 'D' :
819                        'A');
820                 break;
821
822         case STATUSTYPE_TABLE:
823                 DMEMIT("%s %u %s %u ", log->type->name,
824                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
825                        lc->region_size);
826                 DMEMIT_SYNC;
827         }
828
829         return sz;
830 }
831
832 static 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
850 static 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
869 static 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
886 static 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
892 module_init(dm_dirty_log_init);
893 module_exit(dm_dirty_log_exit);
894
895 MODULE_DESCRIPTION(DM_NAME " dirty region log");
896 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
897 MODULE_LICENSE("GPL");