Root/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
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 rw)
295{
296    lc->io_req.bi_rw = rw;
297
298    return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
299}
300
301static int flush_header(struct log_c *lc)
302{
303    struct dm_io_region null_location = {
304        .bdev = lc->header_location.bdev,
305        .sector = 0,
306        .count = 0,
307    };
308
309    lc->io_req.bi_rw = WRITE_FLUSH;
310
311    return dm_io(&lc->io_req, 1, &null_location, NULL);
312}
313
314static int read_header(struct log_c *log)
315{
316    int r;
317
318    r = rw_header(log, READ);
319    if (r)
320        return r;
321
322    header_from_disk(&log->header, log->disk_header);
323
324    /* New log required? */
325    if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
326        log->header.magic = MIRROR_MAGIC;
327        log->header.version = MIRROR_DISK_VERSION;
328        log->header.nr_regions = 0;
329    }
330
331#ifdef __LITTLE_ENDIAN
332    if (log->header.version == 1)
333        log->header.version = 2;
334#endif
335
336    if (log->header.version != MIRROR_DISK_VERSION) {
337        DMWARN("incompatible disk log version");
338        return -EINVAL;
339    }
340
341    return 0;
342}
343
344static int _check_region_size(struct dm_target *ti, uint32_t region_size)
345{
346    if (region_size < 2 || region_size > ti->len)
347        return 0;
348
349    if (!is_power_of_2(region_size))
350        return 0;
351
352    return 1;
353}
354
355/*----------------------------------------------------------------
356 * core log constructor/destructor
357 *
358 * argv contains region_size followed optionally by [no]sync
359 *--------------------------------------------------------------*/
360#define BYTE_SHIFT 3
361static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
362                  unsigned int argc, char **argv,
363                  struct dm_dev *dev)
364{
365    enum sync sync = DEFAULTSYNC;
366
367    struct log_c *lc;
368    uint32_t region_size;
369    unsigned int region_count;
370    size_t bitset_size, buf_size;
371    int r;
372    char dummy;
373
374    if (argc < 1 || argc > 2) {
375        DMWARN("wrong number of arguments to dirty region log");
376        return -EINVAL;
377    }
378
379    if (argc > 1) {
380        if (!strcmp(argv[1], "sync"))
381            sync = FORCESYNC;
382        else if (!strcmp(argv[1], "nosync"))
383            sync = NOSYNC;
384        else {
385            DMWARN("unrecognised sync argument to "
386                   "dirty region log: %s", argv[1]);
387            return -EINVAL;
388        }
389    }
390
391    if (sscanf(argv[0], "%u%c", &region_size, &dummy) != 1 ||
392        !_check_region_size(ti, region_size)) {
393        DMWARN("invalid region size %s", argv[0]);
394        return -EINVAL;
395    }
396
397    region_count = dm_sector_div_up(ti->len, region_size);
398
399    lc = kmalloc(sizeof(*lc), GFP_KERNEL);
400    if (!lc) {
401        DMWARN("couldn't allocate core log");
402        return -ENOMEM;
403    }
404
405    lc->ti = ti;
406    lc->touched_dirtied = 0;
407    lc->touched_cleaned = 0;
408    lc->flush_failed = 0;
409    lc->region_size = region_size;
410    lc->region_count = region_count;
411    lc->sync = sync;
412
413    /*
414     * Work out how many "unsigned long"s we need to hold the bitset.
415     */
416    bitset_size = dm_round_up(region_count,
417                  sizeof(*lc->clean_bits) << BYTE_SHIFT);
418    bitset_size >>= BYTE_SHIFT;
419
420    lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
421
422    /*
423     * Disk log?
424     */
425    if (!dev) {
426        lc->clean_bits = vmalloc(bitset_size);
427        if (!lc->clean_bits) {
428            DMWARN("couldn't allocate clean bitset");
429            kfree(lc);
430            return -ENOMEM;
431        }
432        lc->disk_header = NULL;
433    } else {
434        lc->log_dev = dev;
435        lc->log_dev_failed = 0;
436        lc->log_dev_flush_failed = 0;
437        lc->header_location.bdev = lc->log_dev->bdev;
438        lc->header_location.sector = 0;
439
440        /*
441         * Buffer holds both header and bitset.
442         */
443        buf_size =
444            dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
445                bdev_logical_block_size(lc->header_location.
446                                bdev));
447
448        if (buf_size > i_size_read(dev->bdev->bd_inode)) {
449            DMWARN("log device %s too small: need %llu bytes",
450                dev->name, (unsigned long long)buf_size);
451            kfree(lc);
452            return -EINVAL;
453        }
454
455        lc->header_location.count = buf_size >> SECTOR_SHIFT;
456
457        lc->io_req.mem.type = DM_IO_VMA;
458        lc->io_req.notify.fn = NULL;
459        lc->io_req.client = dm_io_client_create();
460        if (IS_ERR(lc->io_req.client)) {
461            r = PTR_ERR(lc->io_req.client);
462            DMWARN("couldn't allocate disk io client");
463            kfree(lc);
464            return r;
465        }
466
467        lc->disk_header = vmalloc(buf_size);
468        if (!lc->disk_header) {
469            DMWARN("couldn't allocate disk log buffer");
470            dm_io_client_destroy(lc->io_req.client);
471            kfree(lc);
472            return -ENOMEM;
473        }
474
475        lc->io_req.mem.ptr.vma = lc->disk_header;
476        lc->clean_bits = (void *)lc->disk_header +
477                 (LOG_OFFSET << SECTOR_SHIFT);
478    }
479
480    memset(lc->clean_bits, -1, bitset_size);
481
482    lc->sync_bits = vmalloc(bitset_size);
483    if (!lc->sync_bits) {
484        DMWARN("couldn't allocate sync bitset");
485        if (!dev)
486            vfree(lc->clean_bits);
487        else
488            dm_io_client_destroy(lc->io_req.client);
489        vfree(lc->disk_header);
490        kfree(lc);
491        return -ENOMEM;
492    }
493    memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
494    lc->sync_count = (sync == NOSYNC) ? region_count : 0;
495
496    lc->recovering_bits = vzalloc(bitset_size);
497    if (!lc->recovering_bits) {
498        DMWARN("couldn't allocate sync bitset");
499        vfree(lc->sync_bits);
500        if (!dev)
501            vfree(lc->clean_bits);
502        else
503            dm_io_client_destroy(lc->io_req.client);
504        vfree(lc->disk_header);
505        kfree(lc);
506        return -ENOMEM;
507    }
508    lc->sync_search = 0;
509    log->context = lc;
510
511    return 0;
512}
513
514static 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
520static void destroy_log_context(struct log_c *lc)
521{
522    vfree(lc->sync_bits);
523    vfree(lc->recovering_bits);
524    kfree(lc);
525}
526
527static 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 *--------------------------------------------------------------*/
540static 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
564static 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
574static void fail_log_device(struct log_c *lc)
575{
576    if (lc->log_dev_failed)
577        return;
578
579    lc->log_dev_failed = 1;
580    dm_table_event(lc->ti->table);
581}
582
583static int disk_resume(struct dm_dirty_log *log)
584{
585    int r;
586    unsigned i;
587    struct log_c *lc = (struct log_c *) log->context;
588    size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
589
590    /* read the disk header */
591    r = read_header(lc);
592    if (r) {
593        DMWARN("%s: Failed to read header on dirty region log device",
594               lc->log_dev->name);
595        fail_log_device(lc);
596        /*
597         * If the log device cannot be read, we must assume
598         * all regions are out-of-sync. If we simply return
599         * here, the state will be uninitialized and could
600         * lead us to return 'in-sync' status for regions
601         * that are actually 'out-of-sync'.
602         */
603        lc->header.nr_regions = 0;
604    }
605
606    /* set or clear any new bits -- device has grown */
607    if (lc->sync == NOSYNC)
608        for (i = lc->header.nr_regions; i < lc->region_count; i++)
609            /* FIXME: amazingly inefficient */
610            log_set_bit(lc, lc->clean_bits, i);
611    else
612        for (i = lc->header.nr_regions; i < lc->region_count; i++)
613            /* FIXME: amazingly inefficient */
614            log_clear_bit(lc, lc->clean_bits, i);
615
616    /* clear any old bits -- device has shrunk */
617    for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
618        log_clear_bit(lc, lc->clean_bits, i);
619
620    /* copy clean across to sync */
621    memcpy(lc->sync_bits, lc->clean_bits, size);
622    lc->sync_count = memweight(lc->clean_bits,
623                lc->bitset_uint32_count * sizeof(uint32_t));
624    lc->sync_search = 0;
625
626    /* set the correct number of regions in the header */
627    lc->header.nr_regions = lc->region_count;
628
629    header_to_disk(&lc->header, lc->disk_header);
630
631    /* write the new header */
632    r = rw_header(lc, WRITE);
633    if (!r) {
634        r = flush_header(lc);
635        if (r)
636            lc->log_dev_flush_failed = 1;
637    }
638    if (r) {
639        DMWARN("%s: Failed to write header on dirty region log device",
640               lc->log_dev->name);
641        fail_log_device(lc);
642    }
643
644    return r;
645}
646
647static uint32_t core_get_region_size(struct dm_dirty_log *log)
648{
649    struct log_c *lc = (struct log_c *) log->context;
650    return lc->region_size;
651}
652
653static int core_resume(struct dm_dirty_log *log)
654{
655    struct log_c *lc = (struct log_c *) log->context;
656    lc->sync_search = 0;
657    return 0;
658}
659
660static int core_is_clean(struct dm_dirty_log *log, region_t region)
661{
662    struct log_c *lc = (struct log_c *) log->context;
663    return log_test_bit(lc->clean_bits, region);
664}
665
666static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
667{
668    struct log_c *lc = (struct log_c *) log->context;
669    return log_test_bit(lc->sync_bits, region);
670}
671
672static int core_flush(struct dm_dirty_log *log)
673{
674    /* no op */
675    return 0;
676}
677
678static int disk_flush(struct dm_dirty_log *log)
679{
680    int r, i;
681    struct log_c *lc = log->context;
682
683    /* only write if the log has changed */
684    if (!lc->touched_cleaned && !lc->touched_dirtied)
685        return 0;
686
687    if (lc->touched_cleaned && log->flush_callback_fn &&
688        log->flush_callback_fn(lc->ti)) {
689        /*
690         * At this point it is impossible to determine which
691         * regions are clean and which are dirty (without
692         * re-reading the log off disk). So mark all of them
693         * dirty.
694         */
695        lc->flush_failed = 1;
696        for (i = 0; i < lc->region_count; i++)
697            log_clear_bit(lc, lc->clean_bits, i);
698    }
699
700    r = rw_header(lc, WRITE);
701    if (r)
702        fail_log_device(lc);
703    else {
704        if (lc->touched_dirtied) {
705            r = flush_header(lc);
706            if (r) {
707                lc->log_dev_flush_failed = 1;
708                fail_log_device(lc);
709            } else
710                lc->touched_dirtied = 0;
711        }
712        lc->touched_cleaned = 0;
713    }
714
715    return r;
716}
717
718static void core_mark_region(struct dm_dirty_log *log, region_t region)
719{
720    struct log_c *lc = (struct log_c *) log->context;
721    log_clear_bit(lc, lc->clean_bits, region);
722}
723
724static void core_clear_region(struct dm_dirty_log *log, region_t region)
725{
726    struct log_c *lc = (struct log_c *) log->context;
727    if (likely(!lc->flush_failed))
728        log_set_bit(lc, lc->clean_bits, region);
729}
730
731static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
732{
733    struct log_c *lc = (struct log_c *) log->context;
734
735    if (lc->sync_search >= lc->region_count)
736        return 0;
737
738    do {
739        *region = find_next_zero_bit_le(lc->sync_bits,
740                         lc->region_count,
741                         lc->sync_search);
742        lc->sync_search = *region + 1;
743
744        if (*region >= lc->region_count)
745            return 0;
746
747    } while (log_test_bit(lc->recovering_bits, *region));
748
749    log_set_bit(lc, lc->recovering_bits, *region);
750    return 1;
751}
752
753static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
754                 int in_sync)
755{
756    struct log_c *lc = (struct log_c *) log->context;
757
758    log_clear_bit(lc, lc->recovering_bits, region);
759    if (in_sync) {
760        log_set_bit(lc, lc->sync_bits, region);
761                lc->sync_count++;
762        } else if (log_test_bit(lc->sync_bits, region)) {
763        lc->sync_count--;
764        log_clear_bit(lc, lc->sync_bits, region);
765    }
766}
767
768static region_t core_get_sync_count(struct dm_dirty_log *log)
769{
770        struct log_c *lc = (struct log_c *) log->context;
771
772        return lc->sync_count;
773}
774
775#define DMEMIT_SYNC \
776    if (lc->sync != DEFAULTSYNC) \
777        DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
778
779static int core_status(struct dm_dirty_log *log, status_type_t status,
780               char *result, unsigned int maxlen)
781{
782    int sz = 0;
783    struct log_c *lc = log->context;
784
785    switch(status) {
786    case STATUSTYPE_INFO:
787        DMEMIT("1 %s", log->type->name);
788        break;
789
790    case STATUSTYPE_TABLE:
791        DMEMIT("%s %u %u ", log->type->name,
792               lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
793        DMEMIT_SYNC;
794    }
795
796    return sz;
797}
798
799static int disk_status(struct dm_dirty_log *log, status_type_t status,
800               char *result, unsigned int maxlen)
801{
802    int sz = 0;
803    struct log_c *lc = log->context;
804
805    switch(status) {
806    case STATUSTYPE_INFO:
807        DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
808               lc->log_dev_flush_failed ? 'F' :
809               lc->log_dev_failed ? 'D' :
810               'A');
811        break;
812
813    case STATUSTYPE_TABLE:
814        DMEMIT("%s %u %s %u ", log->type->name,
815               lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
816               lc->region_size);
817        DMEMIT_SYNC;
818    }
819
820    return sz;
821}
822
823static struct dm_dirty_log_type _core_type = {
824    .name = "core",
825    .module = THIS_MODULE,
826    .ctr = core_ctr,
827    .dtr = core_dtr,
828    .resume = core_resume,
829    .get_region_size = core_get_region_size,
830    .is_clean = core_is_clean,
831    .in_sync = core_in_sync,
832    .flush = core_flush,
833    .mark_region = core_mark_region,
834    .clear_region = core_clear_region,
835    .get_resync_work = core_get_resync_work,
836    .set_region_sync = core_set_region_sync,
837    .get_sync_count = core_get_sync_count,
838    .status = core_status,
839};
840
841static struct dm_dirty_log_type _disk_type = {
842    .name = "disk",
843    .module = THIS_MODULE,
844    .ctr = disk_ctr,
845    .dtr = disk_dtr,
846    .postsuspend = disk_flush,
847    .resume = disk_resume,
848    .get_region_size = core_get_region_size,
849    .is_clean = core_is_clean,
850    .in_sync = core_in_sync,
851    .flush = disk_flush,
852    .mark_region = core_mark_region,
853    .clear_region = core_clear_region,
854    .get_resync_work = core_get_resync_work,
855    .set_region_sync = core_set_region_sync,
856    .get_sync_count = core_get_sync_count,
857    .status = disk_status,
858};
859
860static int __init dm_dirty_log_init(void)
861{
862    int r;
863
864    r = dm_dirty_log_type_register(&_core_type);
865    if (r)
866        DMWARN("couldn't register core log");
867
868    r = dm_dirty_log_type_register(&_disk_type);
869    if (r) {
870        DMWARN("couldn't register disk type");
871        dm_dirty_log_type_unregister(&_core_type);
872    }
873
874    return r;
875}
876
877static void __exit dm_dirty_log_exit(void)
878{
879    dm_dirty_log_type_unregister(&_disk_type);
880    dm_dirty_log_type_unregister(&_core_type);
881}
882
883module_init(dm_dirty_log_init);
884module_exit(dm_dirty_log_exit);
885
886MODULE_DESCRIPTION(DM_NAME " dirty region log");
887MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
888MODULE_LICENSE("GPL");
889

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