Commit | Line | Data |
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eec40579 JT |
1 | #include "dm.h" |
2 | #include "persistent-data/dm-transaction-manager.h" | |
3 | #include "persistent-data/dm-bitset.h" | |
4 | #include "persistent-data/dm-space-map.h" | |
5 | ||
6 | #include <linux/dm-io.h> | |
7 | #include <linux/dm-kcopyd.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/mempool.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/vmalloc.h> | |
13 | ||
14 | #define DM_MSG_PREFIX "era" | |
15 | ||
16 | #define SUPERBLOCK_LOCATION 0 | |
17 | #define SUPERBLOCK_MAGIC 2126579579 | |
18 | #define SUPERBLOCK_CSUM_XOR 146538381 | |
19 | #define MIN_ERA_VERSION 1 | |
20 | #define MAX_ERA_VERSION 1 | |
21 | #define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION | |
22 | #define MIN_BLOCK_SIZE 8 | |
23 | ||
24 | /*---------------------------------------------------------------- | |
25 | * Writeset | |
26 | *--------------------------------------------------------------*/ | |
27 | struct writeset_metadata { | |
28 | uint32_t nr_bits; | |
29 | dm_block_t root; | |
30 | }; | |
31 | ||
32 | struct writeset { | |
33 | struct writeset_metadata md; | |
34 | ||
35 | /* | |
36 | * An in core copy of the bits to save constantly doing look ups on | |
37 | * disk. | |
38 | */ | |
39 | unsigned long *bits; | |
40 | }; | |
41 | ||
42 | /* | |
43 | * This does not free off the on disk bitset as this will normally be done | |
44 | * after digesting into the era array. | |
45 | */ | |
46 | static void writeset_free(struct writeset *ws) | |
47 | { | |
48 | vfree(ws->bits); | |
49 | } | |
50 | ||
51 | static int setup_on_disk_bitset(struct dm_disk_bitset *info, | |
52 | unsigned nr_bits, dm_block_t *root) | |
53 | { | |
54 | int r; | |
55 | ||
56 | r = dm_bitset_empty(info, root); | |
57 | if (r) | |
58 | return r; | |
59 | ||
60 | return dm_bitset_resize(info, *root, 0, nr_bits, false, root); | |
61 | } | |
62 | ||
63 | static size_t bitset_size(unsigned nr_bits) | |
64 | { | |
65 | return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); | |
66 | } | |
67 | ||
68 | /* | |
69 | * Allocates memory for the in core bitset. | |
70 | */ | |
71 | static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) | |
72 | { | |
73 | ws->md.nr_bits = nr_blocks; | |
74 | ws->md.root = INVALID_WRITESET_ROOT; | |
75 | ws->bits = vzalloc(bitset_size(nr_blocks)); | |
76 | if (!ws->bits) { | |
77 | DMERR("%s: couldn't allocate in memory bitset", __func__); | |
78 | return -ENOMEM; | |
79 | } | |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
84 | /* | |
85 | * Wipes the in-core bitset, and creates a new on disk bitset. | |
86 | */ | |
87 | static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws) | |
88 | { | |
89 | int r; | |
90 | ||
91 | memset(ws->bits, 0, bitset_size(ws->md.nr_bits)); | |
92 | ||
93 | r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root); | |
94 | if (r) { | |
95 | DMERR("%s: setup_on_disk_bitset failed", __func__); | |
96 | return r; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static bool writeset_marked(struct writeset *ws, dm_block_t block) | |
103 | { | |
104 | return test_bit(block, ws->bits); | |
105 | } | |
106 | ||
107 | static int writeset_marked_on_disk(struct dm_disk_bitset *info, | |
108 | struct writeset_metadata *m, dm_block_t block, | |
109 | bool *result) | |
110 | { | |
111 | dm_block_t old = m->root; | |
112 | ||
113 | /* | |
114 | * The bitset was flushed when it was archived, so we know there'll | |
115 | * be no change to the root. | |
116 | */ | |
117 | int r = dm_bitset_test_bit(info, m->root, block, &m->root, result); | |
118 | if (r) { | |
119 | DMERR("%s: dm_bitset_test_bit failed", __func__); | |
120 | return r; | |
121 | } | |
122 | ||
123 | BUG_ON(m->root != old); | |
124 | ||
125 | return r; | |
126 | } | |
127 | ||
128 | /* | |
129 | * Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. | |
130 | */ | |
131 | static int writeset_test_and_set(struct dm_disk_bitset *info, | |
132 | struct writeset *ws, uint32_t block) | |
133 | { | |
134 | int r; | |
135 | ||
136 | if (!test_and_set_bit(block, ws->bits)) { | |
137 | r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root); | |
138 | if (r) { | |
139 | /* FIXME: fail mode */ | |
140 | return r; | |
141 | } | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | return 1; | |
147 | } | |
148 | ||
149 | /*---------------------------------------------------------------- | |
150 | * On disk metadata layout | |
151 | *--------------------------------------------------------------*/ | |
152 | #define SPACE_MAP_ROOT_SIZE 128 | |
153 | #define UUID_LEN 16 | |
154 | ||
155 | struct writeset_disk { | |
156 | __le32 nr_bits; | |
157 | __le64 root; | |
158 | } __packed; | |
159 | ||
160 | struct superblock_disk { | |
161 | __le32 csum; | |
162 | __le32 flags; | |
163 | __le64 blocknr; | |
164 | ||
165 | __u8 uuid[UUID_LEN]; | |
166 | __le64 magic; | |
167 | __le32 version; | |
168 | ||
169 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
170 | ||
171 | __le32 data_block_size; | |
172 | __le32 metadata_block_size; | |
173 | __le32 nr_blocks; | |
174 | ||
175 | __le32 current_era; | |
176 | struct writeset_disk current_writeset; | |
177 | ||
178 | /* | |
179 | * Only these two fields are valid within the metadata snapshot. | |
180 | */ | |
181 | __le64 writeset_tree_root; | |
182 | __le64 era_array_root; | |
183 | ||
184 | __le64 metadata_snap; | |
185 | } __packed; | |
186 | ||
187 | /*---------------------------------------------------------------- | |
188 | * Superblock validation | |
189 | *--------------------------------------------------------------*/ | |
190 | static void sb_prepare_for_write(struct dm_block_validator *v, | |
191 | struct dm_block *b, | |
192 | size_t sb_block_size) | |
193 | { | |
194 | struct superblock_disk *disk = dm_block_data(b); | |
195 | ||
196 | disk->blocknr = cpu_to_le64(dm_block_location(b)); | |
197 | disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
198 | sb_block_size - sizeof(__le32), | |
199 | SUPERBLOCK_CSUM_XOR)); | |
200 | } | |
201 | ||
202 | static int check_metadata_version(struct superblock_disk *disk) | |
203 | { | |
204 | uint32_t metadata_version = le32_to_cpu(disk->version); | |
205 | if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { | |
206 | DMERR("Era metadata version %u found, but only versions between %u and %u supported.", | |
207 | metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); | |
208 | return -EINVAL; | |
209 | } | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | static int sb_check(struct dm_block_validator *v, | |
215 | struct dm_block *b, | |
216 | size_t sb_block_size) | |
217 | { | |
218 | struct superblock_disk *disk = dm_block_data(b); | |
219 | __le32 csum_le; | |
220 | ||
221 | if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { | |
222 | DMERR("sb_check failed: blocknr %llu: wanted %llu", | |
223 | le64_to_cpu(disk->blocknr), | |
224 | (unsigned long long)dm_block_location(b)); | |
225 | return -ENOTBLK; | |
226 | } | |
227 | ||
228 | if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { | |
229 | DMERR("sb_check failed: magic %llu: wanted %llu", | |
230 | le64_to_cpu(disk->magic), | |
231 | (unsigned long long) SUPERBLOCK_MAGIC); | |
232 | return -EILSEQ; | |
233 | } | |
234 | ||
235 | csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
236 | sb_block_size - sizeof(__le32), | |
237 | SUPERBLOCK_CSUM_XOR)); | |
238 | if (csum_le != disk->csum) { | |
239 | DMERR("sb_check failed: csum %u: wanted %u", | |
240 | le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); | |
241 | return -EILSEQ; | |
242 | } | |
243 | ||
244 | return check_metadata_version(disk); | |
245 | } | |
246 | ||
247 | static struct dm_block_validator sb_validator = { | |
248 | .name = "superblock", | |
249 | .prepare_for_write = sb_prepare_for_write, | |
250 | .check = sb_check | |
251 | }; | |
252 | ||
253 | /*---------------------------------------------------------------- | |
254 | * Low level metadata handling | |
255 | *--------------------------------------------------------------*/ | |
256 | #define DM_ERA_METADATA_BLOCK_SIZE 4096 | |
eec40579 JT |
257 | #define ERA_MAX_CONCURRENT_LOCKS 5 |
258 | ||
259 | struct era_metadata { | |
260 | struct block_device *bdev; | |
261 | struct dm_block_manager *bm; | |
262 | struct dm_space_map *sm; | |
263 | struct dm_transaction_manager *tm; | |
264 | ||
265 | dm_block_t block_size; | |
266 | uint32_t nr_blocks; | |
267 | ||
268 | uint32_t current_era; | |
269 | ||
270 | /* | |
271 | * We preallocate 2 writesets. When an era rolls over we | |
272 | * switch between them. This means the allocation is done at | |
273 | * preresume time, rather than on the io path. | |
274 | */ | |
275 | struct writeset writesets[2]; | |
276 | struct writeset *current_writeset; | |
277 | ||
278 | dm_block_t writeset_tree_root; | |
279 | dm_block_t era_array_root; | |
280 | ||
281 | struct dm_disk_bitset bitset_info; | |
282 | struct dm_btree_info writeset_tree_info; | |
283 | struct dm_array_info era_array_info; | |
284 | ||
285 | dm_block_t metadata_snap; | |
286 | ||
287 | /* | |
288 | * A flag that is set whenever a writeset has been archived. | |
289 | */ | |
290 | bool archived_writesets; | |
5a32083d JT |
291 | |
292 | /* | |
293 | * Reading the space map root can fail, so we read it into this | |
294 | * buffer before the superblock is locked and updated. | |
295 | */ | |
296 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
eec40579 JT |
297 | }; |
298 | ||
299 | static int superblock_read_lock(struct era_metadata *md, | |
300 | struct dm_block **sblock) | |
301 | { | |
302 | return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION, | |
303 | &sb_validator, sblock); | |
304 | } | |
305 | ||
306 | static int superblock_lock_zero(struct era_metadata *md, | |
307 | struct dm_block **sblock) | |
308 | { | |
309 | return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION, | |
310 | &sb_validator, sblock); | |
311 | } | |
312 | ||
313 | static int superblock_lock(struct era_metadata *md, | |
314 | struct dm_block **sblock) | |
315 | { | |
316 | return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION, | |
317 | &sb_validator, sblock); | |
318 | } | |
319 | ||
320 | /* FIXME: duplication with cache and thin */ | |
321 | static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result) | |
322 | { | |
323 | int r; | |
324 | unsigned i; | |
325 | struct dm_block *b; | |
326 | __le64 *data_le, zero = cpu_to_le64(0); | |
327 | unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); | |
328 | ||
329 | /* | |
330 | * We can't use a validator here - it may be all zeroes. | |
331 | */ | |
332 | r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b); | |
333 | if (r) | |
334 | return r; | |
335 | ||
336 | data_le = dm_block_data(b); | |
337 | *result = true; | |
338 | for (i = 0; i < sb_block_size; i++) { | |
339 | if (data_le[i] != zero) { | |
340 | *result = false; | |
341 | break; | |
342 | } | |
343 | } | |
344 | ||
4c7da06f MP |
345 | dm_bm_unlock(b); |
346 | ||
347 | return 0; | |
eec40579 JT |
348 | } |
349 | ||
350 | /*----------------------------------------------------------------*/ | |
351 | ||
352 | static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) | |
353 | { | |
354 | disk->nr_bits = cpu_to_le32(core->nr_bits); | |
355 | disk->root = cpu_to_le64(core->root); | |
356 | } | |
357 | ||
358 | static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) | |
359 | { | |
360 | core->nr_bits = le32_to_cpu(disk->nr_bits); | |
361 | core->root = le64_to_cpu(disk->root); | |
362 | } | |
363 | ||
364 | static void ws_inc(void *context, const void *value) | |
365 | { | |
366 | struct era_metadata *md = context; | |
367 | struct writeset_disk ws_d; | |
368 | dm_block_t b; | |
369 | ||
370 | memcpy(&ws_d, value, sizeof(ws_d)); | |
371 | b = le64_to_cpu(ws_d.root); | |
372 | ||
373 | dm_tm_inc(md->tm, b); | |
374 | } | |
375 | ||
376 | static void ws_dec(void *context, const void *value) | |
377 | { | |
378 | struct era_metadata *md = context; | |
379 | struct writeset_disk ws_d; | |
380 | dm_block_t b; | |
381 | ||
382 | memcpy(&ws_d, value, sizeof(ws_d)); | |
383 | b = le64_to_cpu(ws_d.root); | |
384 | ||
385 | dm_bitset_del(&md->bitset_info, b); | |
386 | } | |
387 | ||
388 | static int ws_eq(void *context, const void *value1, const void *value2) | |
389 | { | |
390 | return !memcmp(value1, value2, sizeof(struct writeset_metadata)); | |
391 | } | |
392 | ||
393 | /*----------------------------------------------------------------*/ | |
394 | ||
395 | static void setup_writeset_tree_info(struct era_metadata *md) | |
396 | { | |
397 | struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; | |
398 | md->writeset_tree_info.tm = md->tm; | |
399 | md->writeset_tree_info.levels = 1; | |
400 | vt->context = md; | |
401 | vt->size = sizeof(struct writeset_disk); | |
402 | vt->inc = ws_inc; | |
403 | vt->dec = ws_dec; | |
404 | vt->equal = ws_eq; | |
405 | } | |
406 | ||
407 | static void setup_era_array_info(struct era_metadata *md) | |
408 | ||
409 | { | |
410 | struct dm_btree_value_type vt; | |
411 | vt.context = NULL; | |
412 | vt.size = sizeof(__le32); | |
413 | vt.inc = NULL; | |
414 | vt.dec = NULL; | |
415 | vt.equal = NULL; | |
416 | ||
417 | dm_array_info_init(&md->era_array_info, md->tm, &vt); | |
418 | } | |
419 | ||
420 | static void setup_infos(struct era_metadata *md) | |
421 | { | |
422 | dm_disk_bitset_init(md->tm, &md->bitset_info); | |
423 | setup_writeset_tree_info(md); | |
424 | setup_era_array_info(md); | |
425 | } | |
426 | ||
427 | /*----------------------------------------------------------------*/ | |
428 | ||
429 | static int create_fresh_metadata(struct era_metadata *md) | |
430 | { | |
431 | int r; | |
432 | ||
433 | r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION, | |
434 | &md->tm, &md->sm); | |
435 | if (r < 0) { | |
436 | DMERR("dm_tm_create_with_sm failed"); | |
437 | return r; | |
438 | } | |
439 | ||
440 | setup_infos(md); | |
441 | ||
442 | r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root); | |
443 | if (r) { | |
444 | DMERR("couldn't create new writeset tree"); | |
445 | goto bad; | |
446 | } | |
447 | ||
448 | r = dm_array_empty(&md->era_array_info, &md->era_array_root); | |
449 | if (r) { | |
450 | DMERR("couldn't create era array"); | |
451 | goto bad; | |
452 | } | |
453 | ||
454 | return 0; | |
455 | ||
456 | bad: | |
457 | dm_sm_destroy(md->sm); | |
458 | dm_tm_destroy(md->tm); | |
459 | ||
460 | return r; | |
461 | } | |
462 | ||
5a32083d JT |
463 | static int save_sm_root(struct era_metadata *md) |
464 | { | |
465 | int r; | |
466 | size_t metadata_len; | |
467 | ||
468 | r = dm_sm_root_size(md->sm, &metadata_len); | |
469 | if (r < 0) | |
470 | return r; | |
471 | ||
472 | return dm_sm_copy_root(md->sm, &md->metadata_space_map_root, | |
473 | metadata_len); | |
474 | } | |
475 | ||
476 | static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) | |
477 | { | |
478 | memcpy(&disk->metadata_space_map_root, | |
479 | &md->metadata_space_map_root, | |
480 | sizeof(md->metadata_space_map_root)); | |
481 | } | |
482 | ||
eec40579 JT |
483 | /* |
484 | * Writes a superblock, including the static fields that don't get updated | |
485 | * with every commit (possible optimisation here). 'md' should be fully | |
486 | * constructed when this is called. | |
487 | */ | |
5a32083d | 488 | static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) |
eec40579 | 489 | { |
eec40579 JT |
490 | disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); |
491 | disk->flags = cpu_to_le32(0ul); | |
492 | ||
493 | /* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ | |
494 | memset(disk->uuid, 0, sizeof(disk->uuid)); | |
495 | disk->version = cpu_to_le32(MAX_ERA_VERSION); | |
496 | ||
5a32083d | 497 | copy_sm_root(md, disk); |
eec40579 JT |
498 | |
499 | disk->data_block_size = cpu_to_le32(md->block_size); | |
500 | disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); | |
501 | disk->nr_blocks = cpu_to_le32(md->nr_blocks); | |
502 | disk->current_era = cpu_to_le32(md->current_era); | |
503 | ||
504 | ws_pack(&md->current_writeset->md, &disk->current_writeset); | |
505 | disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); | |
506 | disk->era_array_root = cpu_to_le64(md->era_array_root); | |
507 | disk->metadata_snap = cpu_to_le64(md->metadata_snap); | |
eec40579 JT |
508 | } |
509 | ||
510 | static int write_superblock(struct era_metadata *md) | |
511 | { | |
512 | int r; | |
513 | struct dm_block *sblock; | |
514 | struct superblock_disk *disk; | |
515 | ||
5a32083d JT |
516 | r = save_sm_root(md); |
517 | if (r) { | |
518 | DMERR("%s: save_sm_root failed", __func__); | |
519 | return r; | |
520 | } | |
521 | ||
eec40579 JT |
522 | r = superblock_lock_zero(md, &sblock); |
523 | if (r) | |
524 | return r; | |
525 | ||
526 | disk = dm_block_data(sblock); | |
5a32083d | 527 | prepare_superblock(md, disk); |
eec40579 JT |
528 | |
529 | return dm_tm_commit(md->tm, sblock); | |
530 | } | |
531 | ||
532 | /* | |
533 | * Assumes block_size and the infos are set. | |
534 | */ | |
535 | static int format_metadata(struct era_metadata *md) | |
536 | { | |
537 | int r; | |
538 | ||
539 | r = create_fresh_metadata(md); | |
540 | if (r) | |
541 | return r; | |
542 | ||
543 | r = write_superblock(md); | |
544 | if (r) { | |
545 | dm_sm_destroy(md->sm); | |
546 | dm_tm_destroy(md->tm); | |
547 | return r; | |
548 | } | |
549 | ||
550 | return 0; | |
551 | } | |
552 | ||
553 | static int open_metadata(struct era_metadata *md) | |
554 | { | |
555 | int r; | |
556 | struct dm_block *sblock; | |
557 | struct superblock_disk *disk; | |
558 | ||
559 | r = superblock_read_lock(md, &sblock); | |
560 | if (r) { | |
561 | DMERR("couldn't read_lock superblock"); | |
562 | return r; | |
563 | } | |
564 | ||
565 | disk = dm_block_data(sblock); | |
566 | r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, | |
567 | disk->metadata_space_map_root, | |
568 | sizeof(disk->metadata_space_map_root), | |
569 | &md->tm, &md->sm); | |
570 | if (r) { | |
571 | DMERR("dm_tm_open_with_sm failed"); | |
572 | goto bad; | |
573 | } | |
574 | ||
575 | setup_infos(md); | |
576 | ||
577 | md->block_size = le32_to_cpu(disk->data_block_size); | |
578 | md->nr_blocks = le32_to_cpu(disk->nr_blocks); | |
579 | md->current_era = le32_to_cpu(disk->current_era); | |
580 | ||
581 | md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); | |
582 | md->era_array_root = le64_to_cpu(disk->era_array_root); | |
583 | md->metadata_snap = le64_to_cpu(disk->metadata_snap); | |
584 | md->archived_writesets = true; | |
585 | ||
4c7da06f MP |
586 | dm_bm_unlock(sblock); |
587 | ||
588 | return 0; | |
eec40579 JT |
589 | |
590 | bad: | |
591 | dm_bm_unlock(sblock); | |
592 | return r; | |
593 | } | |
594 | ||
595 | static int open_or_format_metadata(struct era_metadata *md, | |
596 | bool may_format) | |
597 | { | |
598 | int r; | |
599 | bool unformatted = false; | |
600 | ||
601 | r = superblock_all_zeroes(md->bm, &unformatted); | |
602 | if (r) | |
603 | return r; | |
604 | ||
605 | if (unformatted) | |
606 | return may_format ? format_metadata(md) : -EPERM; | |
607 | ||
608 | return open_metadata(md); | |
609 | } | |
610 | ||
611 | static int create_persistent_data_objects(struct era_metadata *md, | |
612 | bool may_format) | |
613 | { | |
614 | int r; | |
615 | ||
616 | md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE, | |
eec40579 JT |
617 | ERA_MAX_CONCURRENT_LOCKS); |
618 | if (IS_ERR(md->bm)) { | |
619 | DMERR("could not create block manager"); | |
620 | return PTR_ERR(md->bm); | |
621 | } | |
622 | ||
623 | r = open_or_format_metadata(md, may_format); | |
624 | if (r) | |
625 | dm_block_manager_destroy(md->bm); | |
626 | ||
627 | return r; | |
628 | } | |
629 | ||
630 | static void destroy_persistent_data_objects(struct era_metadata *md) | |
631 | { | |
632 | dm_sm_destroy(md->sm); | |
633 | dm_tm_destroy(md->tm); | |
634 | dm_block_manager_destroy(md->bm); | |
635 | } | |
636 | ||
637 | /* | |
638 | * This waits until all era_map threads have picked up the new filter. | |
639 | */ | |
640 | static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) | |
641 | { | |
642 | rcu_assign_pointer(md->current_writeset, new_writeset); | |
643 | synchronize_rcu(); | |
644 | } | |
645 | ||
646 | /*---------------------------------------------------------------- | |
647 | * Writesets get 'digested' into the main era array. | |
648 | * | |
649 | * We're using a coroutine here so the worker thread can do the digestion, | |
650 | * thus avoiding synchronisation of the metadata. Digesting a whole | |
651 | * writeset in one go would cause too much latency. | |
652 | *--------------------------------------------------------------*/ | |
653 | struct digest { | |
654 | uint32_t era; | |
655 | unsigned nr_bits, current_bit; | |
656 | struct writeset_metadata writeset; | |
657 | __le32 value; | |
658 | struct dm_disk_bitset info; | |
659 | ||
660 | int (*step)(struct era_metadata *, struct digest *); | |
661 | }; | |
662 | ||
663 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
664 | struct digest *d); | |
665 | ||
666 | static int metadata_digest_remove_writeset(struct era_metadata *md, | |
667 | struct digest *d) | |
668 | { | |
669 | int r; | |
670 | uint64_t key = d->era; | |
671 | ||
672 | r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root, | |
673 | &key, &md->writeset_tree_root); | |
674 | if (r) { | |
675 | DMERR("%s: dm_btree_remove failed", __func__); | |
676 | return r; | |
677 | } | |
678 | ||
679 | d->step = metadata_digest_lookup_writeset; | |
680 | return 0; | |
681 | } | |
682 | ||
683 | #define INSERTS_PER_STEP 100 | |
684 | ||
685 | static int metadata_digest_transcribe_writeset(struct era_metadata *md, | |
686 | struct digest *d) | |
687 | { | |
688 | int r; | |
689 | bool marked; | |
690 | unsigned b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); | |
691 | ||
692 | for (b = d->current_bit; b < e; b++) { | |
693 | r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked); | |
694 | if (r) { | |
695 | DMERR("%s: writeset_marked_on_disk failed", __func__); | |
696 | return r; | |
697 | } | |
698 | ||
699 | if (!marked) | |
700 | continue; | |
701 | ||
702 | __dm_bless_for_disk(&d->value); | |
703 | r = dm_array_set_value(&md->era_array_info, md->era_array_root, | |
704 | b, &d->value, &md->era_array_root); | |
705 | if (r) { | |
706 | DMERR("%s: dm_array_set_value failed", __func__); | |
707 | return r; | |
708 | } | |
709 | } | |
710 | ||
711 | if (b == d->nr_bits) | |
712 | d->step = metadata_digest_remove_writeset; | |
713 | else | |
714 | d->current_bit = b; | |
715 | ||
716 | return 0; | |
717 | } | |
718 | ||
719 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
720 | struct digest *d) | |
721 | { | |
722 | int r; | |
723 | uint64_t key; | |
724 | struct writeset_disk disk; | |
725 | ||
726 | r = dm_btree_find_lowest_key(&md->writeset_tree_info, | |
727 | md->writeset_tree_root, &key); | |
728 | if (r < 0) | |
729 | return r; | |
730 | ||
731 | d->era = key; | |
732 | ||
733 | r = dm_btree_lookup(&md->writeset_tree_info, | |
734 | md->writeset_tree_root, &key, &disk); | |
735 | if (r) { | |
736 | if (r == -ENODATA) { | |
737 | d->step = NULL; | |
738 | return 0; | |
739 | } | |
740 | ||
741 | DMERR("%s: dm_btree_lookup failed", __func__); | |
742 | return r; | |
743 | } | |
744 | ||
745 | ws_unpack(&disk, &d->writeset); | |
746 | d->value = cpu_to_le32(key); | |
747 | ||
748 | d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); | |
749 | d->current_bit = 0; | |
750 | d->step = metadata_digest_transcribe_writeset; | |
751 | ||
752 | return 0; | |
753 | } | |
754 | ||
755 | static int metadata_digest_start(struct era_metadata *md, struct digest *d) | |
756 | { | |
757 | if (d->step) | |
758 | return 0; | |
759 | ||
760 | memset(d, 0, sizeof(*d)); | |
761 | ||
762 | /* | |
763 | * We initialise another bitset info to avoid any caching side | |
764 | * effects with the previous one. | |
765 | */ | |
766 | dm_disk_bitset_init(md->tm, &d->info); | |
767 | d->step = metadata_digest_lookup_writeset; | |
768 | ||
769 | return 0; | |
770 | } | |
771 | ||
772 | /*---------------------------------------------------------------- | |
773 | * High level metadata interface. Target methods should use these, and not | |
774 | * the lower level ones. | |
775 | *--------------------------------------------------------------*/ | |
776 | static struct era_metadata *metadata_open(struct block_device *bdev, | |
777 | sector_t block_size, | |
778 | bool may_format) | |
779 | { | |
780 | int r; | |
781 | struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL); | |
782 | ||
783 | if (!md) | |
784 | return NULL; | |
785 | ||
786 | md->bdev = bdev; | |
787 | md->block_size = block_size; | |
788 | ||
789 | md->writesets[0].md.root = INVALID_WRITESET_ROOT; | |
790 | md->writesets[1].md.root = INVALID_WRITESET_ROOT; | |
791 | md->current_writeset = &md->writesets[0]; | |
792 | ||
793 | r = create_persistent_data_objects(md, may_format); | |
794 | if (r) { | |
795 | kfree(md); | |
796 | return ERR_PTR(r); | |
797 | } | |
798 | ||
799 | return md; | |
800 | } | |
801 | ||
802 | static void metadata_close(struct era_metadata *md) | |
803 | { | |
804 | destroy_persistent_data_objects(md); | |
805 | kfree(md); | |
806 | } | |
807 | ||
808 | static bool valid_nr_blocks(dm_block_t n) | |
809 | { | |
810 | /* | |
811 | * dm_bitset restricts us to 2^32. test_bit & co. restrict us | |
812 | * further to 2^31 - 1 | |
813 | */ | |
814 | return n < (1ull << 31); | |
815 | } | |
816 | ||
817 | static int metadata_resize(struct era_metadata *md, void *arg) | |
818 | { | |
819 | int r; | |
820 | dm_block_t *new_size = arg; | |
821 | __le32 value; | |
822 | ||
823 | if (!valid_nr_blocks(*new_size)) { | |
824 | DMERR("Invalid number of origin blocks %llu", | |
825 | (unsigned long long) *new_size); | |
826 | return -EINVAL; | |
827 | } | |
828 | ||
829 | writeset_free(&md->writesets[0]); | |
830 | writeset_free(&md->writesets[1]); | |
831 | ||
832 | r = writeset_alloc(&md->writesets[0], *new_size); | |
833 | if (r) { | |
834 | DMERR("%s: writeset_alloc failed for writeset 0", __func__); | |
835 | return r; | |
836 | } | |
837 | ||
838 | r = writeset_alloc(&md->writesets[1], *new_size); | |
839 | if (r) { | |
840 | DMERR("%s: writeset_alloc failed for writeset 1", __func__); | |
841 | return r; | |
842 | } | |
843 | ||
844 | value = cpu_to_le32(0u); | |
845 | __dm_bless_for_disk(&value); | |
846 | r = dm_array_resize(&md->era_array_info, md->era_array_root, | |
847 | md->nr_blocks, *new_size, | |
848 | &value, &md->era_array_root); | |
849 | if (r) { | |
850 | DMERR("%s: dm_array_resize failed", __func__); | |
851 | return r; | |
852 | } | |
853 | ||
854 | md->nr_blocks = *new_size; | |
855 | return 0; | |
856 | } | |
857 | ||
858 | static int metadata_era_archive(struct era_metadata *md) | |
859 | { | |
860 | int r; | |
861 | uint64_t keys[1]; | |
862 | struct writeset_disk value; | |
863 | ||
864 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, | |
865 | &md->current_writeset->md.root); | |
866 | if (r) { | |
867 | DMERR("%s: dm_bitset_flush failed", __func__); | |
868 | return r; | |
869 | } | |
870 | ||
871 | ws_pack(&md->current_writeset->md, &value); | |
872 | md->current_writeset->md.root = INVALID_WRITESET_ROOT; | |
873 | ||
874 | keys[0] = md->current_era; | |
875 | __dm_bless_for_disk(&value); | |
876 | r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, | |
877 | keys, &value, &md->writeset_tree_root); | |
878 | if (r) { | |
879 | DMERR("%s: couldn't insert writeset into btree", __func__); | |
880 | /* FIXME: fail mode */ | |
881 | return r; | |
882 | } | |
883 | ||
884 | md->archived_writesets = true; | |
885 | ||
886 | return 0; | |
887 | } | |
888 | ||
889 | static struct writeset *next_writeset(struct era_metadata *md) | |
890 | { | |
891 | return (md->current_writeset == &md->writesets[0]) ? | |
892 | &md->writesets[1] : &md->writesets[0]; | |
893 | } | |
894 | ||
895 | static int metadata_new_era(struct era_metadata *md) | |
896 | { | |
897 | int r; | |
898 | struct writeset *new_writeset = next_writeset(md); | |
899 | ||
900 | r = writeset_init(&md->bitset_info, new_writeset); | |
901 | if (r) { | |
902 | DMERR("%s: writeset_init failed", __func__); | |
903 | return r; | |
904 | } | |
905 | ||
906 | swap_writeset(md, new_writeset); | |
907 | md->current_era++; | |
908 | ||
909 | return 0; | |
910 | } | |
911 | ||
912 | static int metadata_era_rollover(struct era_metadata *md) | |
913 | { | |
914 | int r; | |
915 | ||
916 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { | |
917 | r = metadata_era_archive(md); | |
918 | if (r) { | |
919 | DMERR("%s: metadata_archive_era failed", __func__); | |
920 | /* FIXME: fail mode? */ | |
921 | return r; | |
922 | } | |
923 | } | |
924 | ||
925 | r = metadata_new_era(md); | |
926 | if (r) { | |
927 | DMERR("%s: new era failed", __func__); | |
928 | /* FIXME: fail mode */ | |
929 | return r; | |
930 | } | |
931 | ||
932 | return 0; | |
933 | } | |
934 | ||
935 | static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) | |
936 | { | |
937 | bool r; | |
938 | struct writeset *ws; | |
939 | ||
940 | rcu_read_lock(); | |
941 | ws = rcu_dereference(md->current_writeset); | |
942 | r = writeset_marked(ws, block); | |
943 | rcu_read_unlock(); | |
944 | ||
945 | return r; | |
946 | } | |
947 | ||
948 | static int metadata_commit(struct era_metadata *md) | |
949 | { | |
950 | int r; | |
951 | struct dm_block *sblock; | |
952 | ||
953 | if (md->current_writeset->md.root != SUPERBLOCK_LOCATION) { | |
954 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, | |
955 | &md->current_writeset->md.root); | |
956 | if (r) { | |
957 | DMERR("%s: bitset flush failed", __func__); | |
958 | return r; | |
959 | } | |
960 | } | |
961 | ||
117aceb0 | 962 | r = dm_tm_pre_commit(md->tm); |
5a32083d | 963 | if (r) { |
117aceb0 | 964 | DMERR("%s: pre commit failed", __func__); |
5a32083d JT |
965 | return r; |
966 | } | |
967 | ||
117aceb0 | 968 | r = save_sm_root(md); |
eec40579 | 969 | if (r) { |
117aceb0 | 970 | DMERR("%s: save_sm_root failed", __func__); |
eec40579 JT |
971 | return r; |
972 | } | |
973 | ||
974 | r = superblock_lock(md, &sblock); | |
975 | if (r) { | |
976 | DMERR("%s: superblock lock failed", __func__); | |
977 | return r; | |
978 | } | |
979 | ||
5a32083d | 980 | prepare_superblock(md, dm_block_data(sblock)); |
eec40579 JT |
981 | |
982 | return dm_tm_commit(md->tm, sblock); | |
983 | } | |
984 | ||
985 | static int metadata_checkpoint(struct era_metadata *md) | |
986 | { | |
987 | /* | |
988 | * For now we just rollover, but later I want to put a check in to | |
989 | * avoid this if the filter is still pretty fresh. | |
990 | */ | |
991 | return metadata_era_rollover(md); | |
992 | } | |
993 | ||
994 | /* | |
995 | * Metadata snapshots allow userland to access era data. | |
996 | */ | |
997 | static int metadata_take_snap(struct era_metadata *md) | |
998 | { | |
999 | int r, inc; | |
1000 | struct dm_block *clone; | |
1001 | ||
1002 | if (md->metadata_snap != SUPERBLOCK_LOCATION) { | |
1003 | DMERR("%s: metadata snapshot already exists", __func__); | |
1004 | return -EINVAL; | |
1005 | } | |
1006 | ||
1007 | r = metadata_era_rollover(md); | |
1008 | if (r) { | |
1009 | DMERR("%s: era rollover failed", __func__); | |
1010 | return r; | |
1011 | } | |
1012 | ||
1013 | r = metadata_commit(md); | |
1014 | if (r) { | |
1015 | DMERR("%s: pre commit failed", __func__); | |
1016 | return r; | |
1017 | } | |
1018 | ||
1019 | r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); | |
1020 | if (r) { | |
1021 | DMERR("%s: couldn't increment superblock", __func__); | |
1022 | return r; | |
1023 | } | |
1024 | ||
1025 | r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, | |
1026 | &sb_validator, &clone, &inc); | |
1027 | if (r) { | |
1028 | DMERR("%s: couldn't shadow superblock", __func__); | |
1029 | dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); | |
1030 | return r; | |
1031 | } | |
1032 | BUG_ON(!inc); | |
1033 | ||
1034 | r = dm_sm_inc_block(md->sm, md->writeset_tree_root); | |
1035 | if (r) { | |
1036 | DMERR("%s: couldn't inc writeset tree root", __func__); | |
1037 | dm_tm_unlock(md->tm, clone); | |
1038 | return r; | |
1039 | } | |
1040 | ||
1041 | r = dm_sm_inc_block(md->sm, md->era_array_root); | |
1042 | if (r) { | |
1043 | DMERR("%s: couldn't inc era tree root", __func__); | |
1044 | dm_sm_dec_block(md->sm, md->writeset_tree_root); | |
1045 | dm_tm_unlock(md->tm, clone); | |
1046 | return r; | |
1047 | } | |
1048 | ||
1049 | md->metadata_snap = dm_block_location(clone); | |
1050 | ||
4c7da06f | 1051 | dm_tm_unlock(md->tm, clone); |
eec40579 JT |
1052 | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | static int metadata_drop_snap(struct era_metadata *md) | |
1057 | { | |
1058 | int r; | |
1059 | dm_block_t location; | |
1060 | struct dm_block *clone; | |
1061 | struct superblock_disk *disk; | |
1062 | ||
1063 | if (md->metadata_snap == SUPERBLOCK_LOCATION) { | |
1064 | DMERR("%s: no snap to drop", __func__); | |
1065 | return -EINVAL; | |
1066 | } | |
1067 | ||
1068 | r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); | |
1069 | if (r) { | |
1070 | DMERR("%s: couldn't read lock superblock clone", __func__); | |
1071 | return r; | |
1072 | } | |
1073 | ||
1074 | /* | |
1075 | * Whatever happens now we'll commit with no record of the metadata | |
1076 | * snap. | |
1077 | */ | |
1078 | md->metadata_snap = SUPERBLOCK_LOCATION; | |
1079 | ||
1080 | disk = dm_block_data(clone); | |
1081 | r = dm_btree_del(&md->writeset_tree_info, | |
1082 | le64_to_cpu(disk->writeset_tree_root)); | |
1083 | if (r) { | |
1084 | DMERR("%s: error deleting writeset tree clone", __func__); | |
1085 | dm_tm_unlock(md->tm, clone); | |
1086 | return r; | |
1087 | } | |
1088 | ||
1089 | r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); | |
1090 | if (r) { | |
1091 | DMERR("%s: error deleting era array clone", __func__); | |
1092 | dm_tm_unlock(md->tm, clone); | |
1093 | return r; | |
1094 | } | |
1095 | ||
1096 | location = dm_block_location(clone); | |
1097 | dm_tm_unlock(md->tm, clone); | |
1098 | ||
1099 | return dm_sm_dec_block(md->sm, location); | |
1100 | } | |
1101 | ||
1102 | struct metadata_stats { | |
1103 | dm_block_t used; | |
1104 | dm_block_t total; | |
1105 | dm_block_t snap; | |
1106 | uint32_t era; | |
1107 | }; | |
1108 | ||
1109 | static int metadata_get_stats(struct era_metadata *md, void *ptr) | |
1110 | { | |
1111 | int r; | |
1112 | struct metadata_stats *s = ptr; | |
1113 | dm_block_t nr_free, nr_total; | |
1114 | ||
1115 | r = dm_sm_get_nr_free(md->sm, &nr_free); | |
1116 | if (r) { | |
1117 | DMERR("dm_sm_get_nr_free returned %d", r); | |
1118 | return r; | |
1119 | } | |
1120 | ||
1121 | r = dm_sm_get_nr_blocks(md->sm, &nr_total); | |
1122 | if (r) { | |
1123 | DMERR("dm_pool_get_metadata_dev_size returned %d", r); | |
1124 | return r; | |
1125 | } | |
1126 | ||
1127 | s->used = nr_total - nr_free; | |
1128 | s->total = nr_total; | |
1129 | s->snap = md->metadata_snap; | |
1130 | s->era = md->current_era; | |
1131 | ||
1132 | return 0; | |
1133 | } | |
1134 | ||
1135 | /*----------------------------------------------------------------*/ | |
1136 | ||
1137 | struct era { | |
1138 | struct dm_target *ti; | |
1139 | struct dm_target_callbacks callbacks; | |
1140 | ||
1141 | struct dm_dev *metadata_dev; | |
1142 | struct dm_dev *origin_dev; | |
1143 | ||
1144 | dm_block_t nr_blocks; | |
1145 | uint32_t sectors_per_block; | |
1146 | int sectors_per_block_shift; | |
1147 | struct era_metadata *md; | |
1148 | ||
1149 | struct workqueue_struct *wq; | |
1150 | struct work_struct worker; | |
1151 | ||
1152 | spinlock_t deferred_lock; | |
1153 | struct bio_list deferred_bios; | |
1154 | ||
1155 | spinlock_t rpc_lock; | |
1156 | struct list_head rpc_calls; | |
1157 | ||
1158 | struct digest digest; | |
1159 | atomic_t suspended; | |
1160 | }; | |
1161 | ||
1162 | struct rpc { | |
1163 | struct list_head list; | |
1164 | ||
1165 | int (*fn0)(struct era_metadata *); | |
1166 | int (*fn1)(struct era_metadata *, void *); | |
1167 | void *arg; | |
1168 | int result; | |
1169 | ||
1170 | struct completion complete; | |
1171 | }; | |
1172 | ||
1173 | /*---------------------------------------------------------------- | |
1174 | * Remapping. | |
1175 | *---------------------------------------------------------------*/ | |
1176 | static bool block_size_is_power_of_two(struct era *era) | |
1177 | { | |
1178 | return era->sectors_per_block_shift >= 0; | |
1179 | } | |
1180 | ||
1181 | static dm_block_t get_block(struct era *era, struct bio *bio) | |
1182 | { | |
1183 | sector_t block_nr = bio->bi_iter.bi_sector; | |
1184 | ||
1185 | if (!block_size_is_power_of_two(era)) | |
1186 | (void) sector_div(block_nr, era->sectors_per_block); | |
1187 | else | |
1188 | block_nr >>= era->sectors_per_block_shift; | |
1189 | ||
1190 | return block_nr; | |
1191 | } | |
1192 | ||
1193 | static void remap_to_origin(struct era *era, struct bio *bio) | |
1194 | { | |
74d46992 | 1195 | bio_set_dev(bio, era->origin_dev->bdev); |
eec40579 JT |
1196 | } |
1197 | ||
1198 | /*---------------------------------------------------------------- | |
1199 | * Worker thread | |
1200 | *--------------------------------------------------------------*/ | |
1201 | static void wake_worker(struct era *era) | |
1202 | { | |
1203 | if (!atomic_read(&era->suspended)) | |
1204 | queue_work(era->wq, &era->worker); | |
1205 | } | |
1206 | ||
1207 | static void process_old_eras(struct era *era) | |
1208 | { | |
1209 | int r; | |
1210 | ||
1211 | if (!era->digest.step) | |
1212 | return; | |
1213 | ||
1214 | r = era->digest.step(era->md, &era->digest); | |
1215 | if (r < 0) { | |
1216 | DMERR("%s: digest step failed, stopping digestion", __func__); | |
1217 | era->digest.step = NULL; | |
1218 | ||
1219 | } else if (era->digest.step) | |
1220 | wake_worker(era); | |
1221 | } | |
1222 | ||
1223 | static void process_deferred_bios(struct era *era) | |
1224 | { | |
1225 | int r; | |
1226 | struct bio_list deferred_bios, marked_bios; | |
1227 | struct bio *bio; | |
1228 | bool commit_needed = false; | |
1229 | bool failed = false; | |
1230 | ||
1231 | bio_list_init(&deferred_bios); | |
1232 | bio_list_init(&marked_bios); | |
1233 | ||
1234 | spin_lock(&era->deferred_lock); | |
1235 | bio_list_merge(&deferred_bios, &era->deferred_bios); | |
1236 | bio_list_init(&era->deferred_bios); | |
1237 | spin_unlock(&era->deferred_lock); | |
1238 | ||
1239 | while ((bio = bio_list_pop(&deferred_bios))) { | |
1240 | r = writeset_test_and_set(&era->md->bitset_info, | |
1241 | era->md->current_writeset, | |
1242 | get_block(era, bio)); | |
1243 | if (r < 0) { | |
1244 | /* | |
1245 | * This is bad news, we need to rollback. | |
1246 | * FIXME: finish. | |
1247 | */ | |
1248 | failed = true; | |
1249 | ||
1250 | } else if (r == 0) | |
1251 | commit_needed = true; | |
1252 | ||
1253 | bio_list_add(&marked_bios, bio); | |
1254 | } | |
1255 | ||
1256 | if (commit_needed) { | |
1257 | r = metadata_commit(era->md); | |
1258 | if (r) | |
1259 | failed = true; | |
1260 | } | |
1261 | ||
1262 | if (failed) | |
1263 | while ((bio = bio_list_pop(&marked_bios))) | |
1264 | bio_io_error(bio); | |
1265 | else | |
1266 | while ((bio = bio_list_pop(&marked_bios))) | |
1267 | generic_make_request(bio); | |
1268 | } | |
1269 | ||
1270 | static void process_rpc_calls(struct era *era) | |
1271 | { | |
1272 | int r; | |
1273 | bool need_commit = false; | |
1274 | struct list_head calls; | |
1275 | struct rpc *rpc, *tmp; | |
1276 | ||
1277 | INIT_LIST_HEAD(&calls); | |
1278 | spin_lock(&era->rpc_lock); | |
1279 | list_splice_init(&era->rpc_calls, &calls); | |
1280 | spin_unlock(&era->rpc_lock); | |
1281 | ||
1282 | list_for_each_entry_safe(rpc, tmp, &calls, list) { | |
1283 | rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); | |
1284 | need_commit = true; | |
1285 | } | |
1286 | ||
1287 | if (need_commit) { | |
1288 | r = metadata_commit(era->md); | |
1289 | if (r) | |
1290 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1291 | rpc->result = r; | |
1292 | } | |
1293 | ||
1294 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1295 | complete(&rpc->complete); | |
1296 | } | |
1297 | ||
1298 | static void kick_off_digest(struct era *era) | |
1299 | { | |
1300 | if (era->md->archived_writesets) { | |
1301 | era->md->archived_writesets = false; | |
1302 | metadata_digest_start(era->md, &era->digest); | |
1303 | } | |
1304 | } | |
1305 | ||
1306 | static void do_work(struct work_struct *ws) | |
1307 | { | |
1308 | struct era *era = container_of(ws, struct era, worker); | |
1309 | ||
1310 | kick_off_digest(era); | |
1311 | process_old_eras(era); | |
1312 | process_deferred_bios(era); | |
1313 | process_rpc_calls(era); | |
1314 | } | |
1315 | ||
1316 | static void defer_bio(struct era *era, struct bio *bio) | |
1317 | { | |
1318 | spin_lock(&era->deferred_lock); | |
1319 | bio_list_add(&era->deferred_bios, bio); | |
1320 | spin_unlock(&era->deferred_lock); | |
1321 | ||
1322 | wake_worker(era); | |
1323 | } | |
1324 | ||
1325 | /* | |
1326 | * Make an rpc call to the worker to change the metadata. | |
1327 | */ | |
1328 | static int perform_rpc(struct era *era, struct rpc *rpc) | |
1329 | { | |
1330 | rpc->result = 0; | |
1331 | init_completion(&rpc->complete); | |
1332 | ||
1333 | spin_lock(&era->rpc_lock); | |
1334 | list_add(&rpc->list, &era->rpc_calls); | |
1335 | spin_unlock(&era->rpc_lock); | |
1336 | ||
1337 | wake_worker(era); | |
1338 | wait_for_completion(&rpc->complete); | |
1339 | ||
1340 | return rpc->result; | |
1341 | } | |
1342 | ||
1343 | static int in_worker0(struct era *era, int (*fn)(struct era_metadata *)) | |
1344 | { | |
1345 | struct rpc rpc; | |
1346 | rpc.fn0 = fn; | |
1347 | rpc.fn1 = NULL; | |
1348 | ||
1349 | return perform_rpc(era, &rpc); | |
1350 | } | |
1351 | ||
1352 | static int in_worker1(struct era *era, | |
1353 | int (*fn)(struct era_metadata *, void *), void *arg) | |
1354 | { | |
1355 | struct rpc rpc; | |
1356 | rpc.fn0 = NULL; | |
1357 | rpc.fn1 = fn; | |
1358 | rpc.arg = arg; | |
1359 | ||
1360 | return perform_rpc(era, &rpc); | |
1361 | } | |
1362 | ||
1363 | static void start_worker(struct era *era) | |
1364 | { | |
1365 | atomic_set(&era->suspended, 0); | |
1366 | } | |
1367 | ||
1368 | static void stop_worker(struct era *era) | |
1369 | { | |
1370 | atomic_set(&era->suspended, 1); | |
1371 | flush_workqueue(era->wq); | |
1372 | } | |
1373 | ||
1374 | /*---------------------------------------------------------------- | |
1375 | * Target methods | |
1376 | *--------------------------------------------------------------*/ | |
1377 | static int dev_is_congested(struct dm_dev *dev, int bdi_bits) | |
1378 | { | |
1379 | struct request_queue *q = bdev_get_queue(dev->bdev); | |
dc3b17cc | 1380 | return bdi_congested(q->backing_dev_info, bdi_bits); |
eec40579 JT |
1381 | } |
1382 | ||
1383 | static int era_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
1384 | { | |
1385 | struct era *era = container_of(cb, struct era, callbacks); | |
1386 | return dev_is_congested(era->origin_dev, bdi_bits); | |
1387 | } | |
1388 | ||
1389 | static void era_destroy(struct era *era) | |
1390 | { | |
989f26f5 JT |
1391 | if (era->md) |
1392 | metadata_close(era->md); | |
eec40579 JT |
1393 | |
1394 | if (era->wq) | |
1395 | destroy_workqueue(era->wq); | |
1396 | ||
1397 | if (era->origin_dev) | |
1398 | dm_put_device(era->ti, era->origin_dev); | |
1399 | ||
1400 | if (era->metadata_dev) | |
1401 | dm_put_device(era->ti, era->metadata_dev); | |
1402 | ||
1403 | kfree(era); | |
1404 | } | |
1405 | ||
1406 | static dm_block_t calc_nr_blocks(struct era *era) | |
1407 | { | |
1408 | return dm_sector_div_up(era->ti->len, era->sectors_per_block); | |
1409 | } | |
1410 | ||
1411 | static bool valid_block_size(dm_block_t block_size) | |
1412 | { | |
1413 | bool greater_than_zero = block_size > 0; | |
1414 | bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; | |
1415 | ||
1416 | return greater_than_zero && multiple_of_min_block_size; | |
1417 | } | |
1418 | ||
1419 | /* | |
1420 | * <metadata dev> <data dev> <data block size (sectors)> | |
1421 | */ | |
1422 | static int era_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1423 | { | |
1424 | int r; | |
1425 | char dummy; | |
1426 | struct era *era; | |
1427 | struct era_metadata *md; | |
1428 | ||
1429 | if (argc != 3) { | |
1430 | ti->error = "Invalid argument count"; | |
1431 | return -EINVAL; | |
1432 | } | |
1433 | ||
1434 | era = kzalloc(sizeof(*era), GFP_KERNEL); | |
1435 | if (!era) { | |
1436 | ti->error = "Error allocating era structure"; | |
1437 | return -ENOMEM; | |
1438 | } | |
1439 | ||
1440 | era->ti = ti; | |
1441 | ||
1442 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &era->metadata_dev); | |
1443 | if (r) { | |
1444 | ti->error = "Error opening metadata device"; | |
1445 | era_destroy(era); | |
1446 | return -EINVAL; | |
1447 | } | |
1448 | ||
1449 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &era->origin_dev); | |
1450 | if (r) { | |
1451 | ti->error = "Error opening data device"; | |
1452 | era_destroy(era); | |
1453 | return -EINVAL; | |
1454 | } | |
1455 | ||
1456 | r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); | |
1457 | if (r != 1) { | |
1458 | ti->error = "Error parsing block size"; | |
1459 | era_destroy(era); | |
1460 | return -EINVAL; | |
1461 | } | |
1462 | ||
1463 | r = dm_set_target_max_io_len(ti, era->sectors_per_block); | |
1464 | if (r) { | |
1465 | ti->error = "could not set max io len"; | |
1466 | era_destroy(era); | |
1467 | return -EINVAL; | |
1468 | } | |
1469 | ||
1470 | if (!valid_block_size(era->sectors_per_block)) { | |
1471 | ti->error = "Invalid block size"; | |
1472 | era_destroy(era); | |
1473 | return -EINVAL; | |
1474 | } | |
1475 | if (era->sectors_per_block & (era->sectors_per_block - 1)) | |
1476 | era->sectors_per_block_shift = -1; | |
1477 | else | |
1478 | era->sectors_per_block_shift = __ffs(era->sectors_per_block); | |
1479 | ||
1480 | md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); | |
1481 | if (IS_ERR(md)) { | |
1482 | ti->error = "Error reading metadata"; | |
1483 | era_destroy(era); | |
1484 | return PTR_ERR(md); | |
1485 | } | |
1486 | era->md = md; | |
1487 | ||
1488 | era->nr_blocks = calc_nr_blocks(era); | |
1489 | ||
1490 | r = metadata_resize(era->md, &era->nr_blocks); | |
1491 | if (r) { | |
1492 | ti->error = "couldn't resize metadata"; | |
1493 | era_destroy(era); | |
1494 | return -ENOMEM; | |
1495 | } | |
1496 | ||
1497 | era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
1498 | if (!era->wq) { | |
1499 | ti->error = "could not create workqueue for metadata object"; | |
1500 | era_destroy(era); | |
1501 | return -ENOMEM; | |
1502 | } | |
1503 | INIT_WORK(&era->worker, do_work); | |
1504 | ||
1505 | spin_lock_init(&era->deferred_lock); | |
1506 | bio_list_init(&era->deferred_bios); | |
1507 | ||
1508 | spin_lock_init(&era->rpc_lock); | |
1509 | INIT_LIST_HEAD(&era->rpc_calls); | |
1510 | ||
1511 | ti->private = era; | |
1512 | ti->num_flush_bios = 1; | |
1513 | ti->flush_supported = true; | |
1514 | ||
1515 | ti->num_discard_bios = 1; | |
eec40579 JT |
1516 | era->callbacks.congested_fn = era_is_congested; |
1517 | dm_table_add_target_callbacks(ti->table, &era->callbacks); | |
1518 | ||
1519 | return 0; | |
1520 | } | |
1521 | ||
1522 | static void era_dtr(struct dm_target *ti) | |
1523 | { | |
1524 | era_destroy(ti->private); | |
1525 | } | |
1526 | ||
1527 | static int era_map(struct dm_target *ti, struct bio *bio) | |
1528 | { | |
1529 | struct era *era = ti->private; | |
1530 | dm_block_t block = get_block(era, bio); | |
1531 | ||
1532 | /* | |
1533 | * All bios get remapped to the origin device. We do this now, but | |
1534 | * it may not get issued until later. Depending on whether the | |
1535 | * block is marked in this era. | |
1536 | */ | |
1537 | remap_to_origin(era, bio); | |
1538 | ||
1539 | /* | |
28a8f0d3 | 1540 | * REQ_PREFLUSH bios carry no data, so we're not interested in them. |
eec40579 | 1541 | */ |
1eff9d32 | 1542 | if (!(bio->bi_opf & REQ_PREFLUSH) && |
eec40579 JT |
1543 | (bio_data_dir(bio) == WRITE) && |
1544 | !metadata_current_marked(era->md, block)) { | |
1545 | defer_bio(era, bio); | |
1546 | return DM_MAPIO_SUBMITTED; | |
1547 | } | |
1548 | ||
1549 | return DM_MAPIO_REMAPPED; | |
1550 | } | |
1551 | ||
1552 | static void era_postsuspend(struct dm_target *ti) | |
1553 | { | |
1554 | int r; | |
1555 | struct era *era = ti->private; | |
1556 | ||
1557 | r = in_worker0(era, metadata_era_archive); | |
1558 | if (r) { | |
1559 | DMERR("%s: couldn't archive current era", __func__); | |
1560 | /* FIXME: fail mode */ | |
1561 | } | |
1562 | ||
1563 | stop_worker(era); | |
1564 | } | |
1565 | ||
1566 | static int era_preresume(struct dm_target *ti) | |
1567 | { | |
1568 | int r; | |
1569 | struct era *era = ti->private; | |
1570 | dm_block_t new_size = calc_nr_blocks(era); | |
1571 | ||
1572 | if (era->nr_blocks != new_size) { | |
1573 | r = in_worker1(era, metadata_resize, &new_size); | |
1574 | if (r) | |
1575 | return r; | |
1576 | ||
1577 | era->nr_blocks = new_size; | |
1578 | } | |
1579 | ||
1580 | start_worker(era); | |
1581 | ||
1582 | r = in_worker0(era, metadata_new_era); | |
1583 | if (r) { | |
1584 | DMERR("%s: metadata_era_rollover failed", __func__); | |
1585 | return r; | |
1586 | } | |
1587 | ||
1588 | return 0; | |
1589 | } | |
1590 | ||
1591 | /* | |
1592 | * Status format: | |
1593 | * | |
1594 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> | |
1595 | * <current era> <held metadata root | '-'> | |
1596 | */ | |
1597 | static void era_status(struct dm_target *ti, status_type_t type, | |
1598 | unsigned status_flags, char *result, unsigned maxlen) | |
1599 | { | |
1600 | int r; | |
1601 | struct era *era = ti->private; | |
1602 | ssize_t sz = 0; | |
1603 | struct metadata_stats stats; | |
1604 | char buf[BDEVNAME_SIZE]; | |
1605 | ||
1606 | switch (type) { | |
1607 | case STATUSTYPE_INFO: | |
1608 | r = in_worker1(era, metadata_get_stats, &stats); | |
1609 | if (r) | |
1610 | goto err; | |
1611 | ||
1612 | DMEMIT("%u %llu/%llu %u", | |
1613 | (unsigned) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), | |
1614 | (unsigned long long) stats.used, | |
1615 | (unsigned long long) stats.total, | |
1616 | (unsigned) stats.era); | |
1617 | ||
1618 | if (stats.snap != SUPERBLOCK_LOCATION) | |
1619 | DMEMIT(" %llu", stats.snap); | |
1620 | else | |
1621 | DMEMIT(" -"); | |
1622 | break; | |
1623 | ||
1624 | case STATUSTYPE_TABLE: | |
1625 | format_dev_t(buf, era->metadata_dev->bdev->bd_dev); | |
1626 | DMEMIT("%s ", buf); | |
1627 | format_dev_t(buf, era->origin_dev->bdev->bd_dev); | |
1628 | DMEMIT("%s %u", buf, era->sectors_per_block); | |
1629 | break; | |
1630 | } | |
1631 | ||
1632 | return; | |
1633 | ||
1634 | err: | |
1635 | DMEMIT("Error"); | |
1636 | } | |
1637 | ||
1eb5fa84 MS |
1638 | static int era_message(struct dm_target *ti, unsigned argc, char **argv, |
1639 | char *result, unsigned maxlen) | |
eec40579 JT |
1640 | { |
1641 | struct era *era = ti->private; | |
1642 | ||
1643 | if (argc != 1) { | |
1644 | DMERR("incorrect number of message arguments"); | |
1645 | return -EINVAL; | |
1646 | } | |
1647 | ||
1648 | if (!strcasecmp(argv[0], "checkpoint")) | |
1649 | return in_worker0(era, metadata_checkpoint); | |
1650 | ||
1651 | if (!strcasecmp(argv[0], "take_metadata_snap")) | |
1652 | return in_worker0(era, metadata_take_snap); | |
1653 | ||
1654 | if (!strcasecmp(argv[0], "drop_metadata_snap")) | |
1655 | return in_worker0(era, metadata_drop_snap); | |
1656 | ||
1657 | DMERR("unsupported message '%s'", argv[0]); | |
1658 | return -EINVAL; | |
1659 | } | |
1660 | ||
1661 | static sector_t get_dev_size(struct dm_dev *dev) | |
1662 | { | |
1663 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
1664 | } | |
1665 | ||
1666 | static int era_iterate_devices(struct dm_target *ti, | |
1667 | iterate_devices_callout_fn fn, void *data) | |
1668 | { | |
1669 | struct era *era = ti->private; | |
1670 | return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); | |
1671 | } | |
1672 | ||
eec40579 JT |
1673 | static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) |
1674 | { | |
1675 | struct era *era = ti->private; | |
1676 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; | |
1677 | ||
1678 | /* | |
1679 | * If the system-determined stacked limits are compatible with the | |
1680 | * era device's blocksize (io_opt is a factor) do not override them. | |
1681 | */ | |
1682 | if (io_opt_sectors < era->sectors_per_block || | |
1683 | do_div(io_opt_sectors, era->sectors_per_block)) { | |
1684 | blk_limits_io_min(limits, 0); | |
1685 | blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT); | |
1686 | } | |
1687 | } | |
1688 | ||
1689 | /*----------------------------------------------------------------*/ | |
1690 | ||
1691 | static struct target_type era_target = { | |
1692 | .name = "era", | |
1693 | .version = {1, 0, 0}, | |
1694 | .module = THIS_MODULE, | |
1695 | .ctr = era_ctr, | |
1696 | .dtr = era_dtr, | |
1697 | .map = era_map, | |
1698 | .postsuspend = era_postsuspend, | |
1699 | .preresume = era_preresume, | |
1700 | .status = era_status, | |
1701 | .message = era_message, | |
1702 | .iterate_devices = era_iterate_devices, | |
eec40579 JT |
1703 | .io_hints = era_io_hints |
1704 | }; | |
1705 | ||
1706 | static int __init dm_era_init(void) | |
1707 | { | |
1708 | int r; | |
1709 | ||
1710 | r = dm_register_target(&era_target); | |
1711 | if (r) { | |
1712 | DMERR("era target registration failed: %d", r); | |
1713 | return r; | |
1714 | } | |
1715 | ||
1716 | return 0; | |
1717 | } | |
1718 | ||
1719 | static void __exit dm_era_exit(void) | |
1720 | { | |
1721 | dm_unregister_target(&era_target); | |
1722 | } | |
1723 | ||
1724 | module_init(dm_era_init); | |
1725 | module_exit(dm_era_exit); | |
1726 | ||
1727 | MODULE_DESCRIPTION(DM_NAME " era target"); | |
1728 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
1729 | MODULE_LICENSE("GPL"); |