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1 | /* |
2 | * Copyright (C) 2003 Sistina Software |
3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
4 | * |
5 | * This file is released under the LGPL. |
6 | */ |
7 | |
8 | #include <linux/init.h> |
9 | #include <linux/slab.h> |
10 | #include <linux/module.h> |
11 | #include <linux/vmalloc.h> |
12 | #include <linux/dm-io.h> |
13 | #include <linux/dm-dirty-log.h> |
14 | |
15 | #include <linux/device-mapper.h> |
16 | |
17 | #define DM_MSG_PREFIX "dirty region log" |
18 | |
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 | char dummy; |
373 | |
374 | if (argc < 1 || argc > 2) { |
375 | DMWARN("wrong number of arguments to dirty region log"); |
376 | return -EINVAL; |
377 | } |
378 | |
379 | if (argc > 1) { |
380 | if (!strcmp(argv[1], "sync")) |
381 | sync = FORCESYNC; |
382 | else if (!strcmp(argv[1], "nosync")) |
383 | sync = NOSYNC; |
384 | else { |
385 | DMWARN("unrecognised sync argument to " |
386 | "dirty region log: %s", argv[1]); |
387 | return -EINVAL; |
388 | } |
389 | } |
390 | |
391 | if (sscanf(argv[0], "%u%c", ®ion_size, &dummy) != 1 || |
392 | !_check_region_size(ti, region_size)) { |
393 | DMWARN("invalid region size %s", argv[0]); |
394 | return -EINVAL; |
395 | } |
396 | |
397 | region_count = dm_sector_div_up(ti->len, region_size); |
398 | |
399 | lc = kmalloc(sizeof(*lc), GFP_KERNEL); |
400 | if (!lc) { |
401 | DMWARN("couldn't allocate core log"); |
402 | return -ENOMEM; |
403 | } |
404 | |
405 | lc->ti = ti; |
406 | lc->touched_dirtied = 0; |
407 | lc->touched_cleaned = 0; |
408 | lc->flush_failed = 0; |
409 | lc->region_size = region_size; |
410 | lc->region_count = region_count; |
411 | lc->sync = sync; |
412 | |
413 | /* |
414 | * Work out how many "unsigned long"s we need to hold the bitset. |
415 | */ |
416 | bitset_size = dm_round_up(region_count, |
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 | |
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 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 | |
583 | static 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 | |
647 | static 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 | |
653 | static 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 | |
660 | static 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 | |
666 | static 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 | |
672 | static int core_flush(struct dm_dirty_log *log) |
673 | { |
674 | /* no op */ |
675 | return 0; |
676 | } |
677 | |
678 | static 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 | |
718 | static 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 | |
724 | static 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 | |
731 | static 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 | |
753 | static 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 | |
768 | static 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 | |
779 | static 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 | |
799 | static 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 | |
823 | static 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 | |
841 | static 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 | |
860 | static 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 | |
877 | static 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 | |
883 | module_init(dm_dirty_log_init); |
884 | module_exit(dm_dirty_log_exit); |
885 | |
886 | MODULE_DESCRIPTION(DM_NAME " dirty region log"); |
887 | MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>"); |
888 | MODULE_LICENSE("GPL"); |
889 |
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