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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
eec40579 JT |
2 | #include "dm.h" |
3 | #include "persistent-data/dm-transaction-manager.h" | |
4 | #include "persistent-data/dm-bitset.h" | |
5 | #include "persistent-data/dm-space-map.h" | |
6 | ||
7 | #include <linux/dm-io.h> | |
8 | #include <linux/dm-kcopyd.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/mempool.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/vmalloc.h> | |
14 | ||
15 | #define DM_MSG_PREFIX "era" | |
16 | ||
17 | #define SUPERBLOCK_LOCATION 0 | |
18 | #define SUPERBLOCK_MAGIC 2126579579 | |
19 | #define SUPERBLOCK_CSUM_XOR 146538381 | |
20 | #define MIN_ERA_VERSION 1 | |
21 | #define MAX_ERA_VERSION 1 | |
22 | #define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION | |
23 | #define MIN_BLOCK_SIZE 8 | |
24 | ||
25 | /*---------------------------------------------------------------- | |
26 | * Writeset | |
27 | *--------------------------------------------------------------*/ | |
28 | struct writeset_metadata { | |
29 | uint32_t nr_bits; | |
30 | dm_block_t root; | |
31 | }; | |
32 | ||
33 | struct writeset { | |
34 | struct writeset_metadata md; | |
35 | ||
36 | /* | |
37 | * An in core copy of the bits to save constantly doing look ups on | |
38 | * disk. | |
39 | */ | |
40 | unsigned long *bits; | |
41 | }; | |
42 | ||
43 | /* | |
44 | * This does not free off the on disk bitset as this will normally be done | |
45 | * after digesting into the era array. | |
46 | */ | |
47 | static void writeset_free(struct writeset *ws) | |
48 | { | |
49 | vfree(ws->bits); | |
50 | } | |
51 | ||
52 | static int setup_on_disk_bitset(struct dm_disk_bitset *info, | |
53 | unsigned nr_bits, dm_block_t *root) | |
54 | { | |
55 | int r; | |
56 | ||
57 | r = dm_bitset_empty(info, root); | |
58 | if (r) | |
59 | return r; | |
60 | ||
61 | return dm_bitset_resize(info, *root, 0, nr_bits, false, root); | |
62 | } | |
63 | ||
64 | static size_t bitset_size(unsigned nr_bits) | |
65 | { | |
66 | return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); | |
67 | } | |
68 | ||
69 | /* | |
70 | * Allocates memory for the in core bitset. | |
71 | */ | |
72 | static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) | |
73 | { | |
74 | ws->md.nr_bits = nr_blocks; | |
75 | ws->md.root = INVALID_WRITESET_ROOT; | |
76 | ws->bits = vzalloc(bitset_size(nr_blocks)); | |
77 | if (!ws->bits) { | |
78 | DMERR("%s: couldn't allocate in memory bitset", __func__); | |
79 | return -ENOMEM; | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Wipes the in-core bitset, and creates a new on disk bitset. | |
87 | */ | |
88 | static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws) | |
89 | { | |
90 | int r; | |
91 | ||
92 | memset(ws->bits, 0, bitset_size(ws->md.nr_bits)); | |
93 | ||
94 | r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root); | |
95 | if (r) { | |
96 | DMERR("%s: setup_on_disk_bitset failed", __func__); | |
97 | return r; | |
98 | } | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static bool writeset_marked(struct writeset *ws, dm_block_t block) | |
104 | { | |
105 | return test_bit(block, ws->bits); | |
106 | } | |
107 | ||
108 | static int writeset_marked_on_disk(struct dm_disk_bitset *info, | |
109 | struct writeset_metadata *m, dm_block_t block, | |
110 | bool *result) | |
111 | { | |
112 | dm_block_t old = m->root; | |
113 | ||
114 | /* | |
115 | * The bitset was flushed when it was archived, so we know there'll | |
116 | * be no change to the root. | |
117 | */ | |
118 | int r = dm_bitset_test_bit(info, m->root, block, &m->root, result); | |
119 | if (r) { | |
120 | DMERR("%s: dm_bitset_test_bit failed", __func__); | |
121 | return r; | |
122 | } | |
123 | ||
124 | BUG_ON(m->root != old); | |
125 | ||
126 | return r; | |
127 | } | |
128 | ||
129 | /* | |
130 | * Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. | |
131 | */ | |
132 | static int writeset_test_and_set(struct dm_disk_bitset *info, | |
133 | struct writeset *ws, uint32_t block) | |
134 | { | |
135 | int r; | |
136 | ||
137 | if (!test_and_set_bit(block, ws->bits)) { | |
138 | r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root); | |
139 | if (r) { | |
140 | /* FIXME: fail mode */ | |
141 | return r; | |
142 | } | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | return 1; | |
148 | } | |
149 | ||
150 | /*---------------------------------------------------------------- | |
151 | * On disk metadata layout | |
152 | *--------------------------------------------------------------*/ | |
153 | #define SPACE_MAP_ROOT_SIZE 128 | |
154 | #define UUID_LEN 16 | |
155 | ||
156 | struct writeset_disk { | |
157 | __le32 nr_bits; | |
158 | __le64 root; | |
159 | } __packed; | |
160 | ||
161 | struct superblock_disk { | |
162 | __le32 csum; | |
163 | __le32 flags; | |
164 | __le64 blocknr; | |
165 | ||
166 | __u8 uuid[UUID_LEN]; | |
167 | __le64 magic; | |
168 | __le32 version; | |
169 | ||
170 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
171 | ||
172 | __le32 data_block_size; | |
173 | __le32 metadata_block_size; | |
174 | __le32 nr_blocks; | |
175 | ||
176 | __le32 current_era; | |
177 | struct writeset_disk current_writeset; | |
178 | ||
179 | /* | |
180 | * Only these two fields are valid within the metadata snapshot. | |
181 | */ | |
182 | __le64 writeset_tree_root; | |
183 | __le64 era_array_root; | |
184 | ||
185 | __le64 metadata_snap; | |
186 | } __packed; | |
187 | ||
188 | /*---------------------------------------------------------------- | |
189 | * Superblock validation | |
190 | *--------------------------------------------------------------*/ | |
191 | static void sb_prepare_for_write(struct dm_block_validator *v, | |
192 | struct dm_block *b, | |
193 | size_t sb_block_size) | |
194 | { | |
195 | struct superblock_disk *disk = dm_block_data(b); | |
196 | ||
197 | disk->blocknr = cpu_to_le64(dm_block_location(b)); | |
198 | disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
199 | sb_block_size - sizeof(__le32), | |
200 | SUPERBLOCK_CSUM_XOR)); | |
201 | } | |
202 | ||
203 | static int check_metadata_version(struct superblock_disk *disk) | |
204 | { | |
205 | uint32_t metadata_version = le32_to_cpu(disk->version); | |
206 | if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { | |
207 | DMERR("Era metadata version %u found, but only versions between %u and %u supported.", | |
208 | metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); | |
209 | return -EINVAL; | |
210 | } | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static int sb_check(struct dm_block_validator *v, | |
216 | struct dm_block *b, | |
217 | size_t sb_block_size) | |
218 | { | |
219 | struct superblock_disk *disk = dm_block_data(b); | |
220 | __le32 csum_le; | |
221 | ||
222 | if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { | |
223 | DMERR("sb_check failed: blocknr %llu: wanted %llu", | |
224 | le64_to_cpu(disk->blocknr), | |
225 | (unsigned long long)dm_block_location(b)); | |
226 | return -ENOTBLK; | |
227 | } | |
228 | ||
229 | if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { | |
230 | DMERR("sb_check failed: magic %llu: wanted %llu", | |
231 | le64_to_cpu(disk->magic), | |
232 | (unsigned long long) SUPERBLOCK_MAGIC); | |
233 | return -EILSEQ; | |
234 | } | |
235 | ||
236 | csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
237 | sb_block_size - sizeof(__le32), | |
238 | SUPERBLOCK_CSUM_XOR)); | |
239 | if (csum_le != disk->csum) { | |
240 | DMERR("sb_check failed: csum %u: wanted %u", | |
241 | le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); | |
242 | return -EILSEQ; | |
243 | } | |
244 | ||
245 | return check_metadata_version(disk); | |
246 | } | |
247 | ||
248 | static struct dm_block_validator sb_validator = { | |
249 | .name = "superblock", | |
250 | .prepare_for_write = sb_prepare_for_write, | |
251 | .check = sb_check | |
252 | }; | |
253 | ||
254 | /*---------------------------------------------------------------- | |
255 | * Low level metadata handling | |
256 | *--------------------------------------------------------------*/ | |
257 | #define DM_ERA_METADATA_BLOCK_SIZE 4096 | |
eec40579 JT |
258 | #define ERA_MAX_CONCURRENT_LOCKS 5 |
259 | ||
260 | struct era_metadata { | |
261 | struct block_device *bdev; | |
262 | struct dm_block_manager *bm; | |
263 | struct dm_space_map *sm; | |
264 | struct dm_transaction_manager *tm; | |
265 | ||
266 | dm_block_t block_size; | |
267 | uint32_t nr_blocks; | |
268 | ||
269 | uint32_t current_era; | |
270 | ||
271 | /* | |
272 | * We preallocate 2 writesets. When an era rolls over we | |
273 | * switch between them. This means the allocation is done at | |
274 | * preresume time, rather than on the io path. | |
275 | */ | |
276 | struct writeset writesets[2]; | |
277 | struct writeset *current_writeset; | |
278 | ||
279 | dm_block_t writeset_tree_root; | |
280 | dm_block_t era_array_root; | |
281 | ||
282 | struct dm_disk_bitset bitset_info; | |
283 | struct dm_btree_info writeset_tree_info; | |
284 | struct dm_array_info era_array_info; | |
285 | ||
286 | dm_block_t metadata_snap; | |
287 | ||
288 | /* | |
289 | * A flag that is set whenever a writeset has been archived. | |
290 | */ | |
291 | bool archived_writesets; | |
5a32083d JT |
292 | |
293 | /* | |
294 | * Reading the space map root can fail, so we read it into this | |
295 | * buffer before the superblock is locked and updated. | |
296 | */ | |
297 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
eec40579 JT |
298 | }; |
299 | ||
300 | static int superblock_read_lock(struct era_metadata *md, | |
301 | struct dm_block **sblock) | |
302 | { | |
303 | return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION, | |
304 | &sb_validator, sblock); | |
305 | } | |
306 | ||
307 | static int superblock_lock_zero(struct era_metadata *md, | |
308 | struct dm_block **sblock) | |
309 | { | |
310 | return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION, | |
311 | &sb_validator, sblock); | |
312 | } | |
313 | ||
314 | static int superblock_lock(struct era_metadata *md, | |
315 | struct dm_block **sblock) | |
316 | { | |
317 | return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION, | |
318 | &sb_validator, sblock); | |
319 | } | |
320 | ||
321 | /* FIXME: duplication with cache and thin */ | |
322 | static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result) | |
323 | { | |
324 | int r; | |
325 | unsigned i; | |
326 | struct dm_block *b; | |
327 | __le64 *data_le, zero = cpu_to_le64(0); | |
328 | unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); | |
329 | ||
330 | /* | |
331 | * We can't use a validator here - it may be all zeroes. | |
332 | */ | |
333 | r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b); | |
334 | if (r) | |
335 | return r; | |
336 | ||
337 | data_le = dm_block_data(b); | |
338 | *result = true; | |
339 | for (i = 0; i < sb_block_size; i++) { | |
340 | if (data_le[i] != zero) { | |
341 | *result = false; | |
342 | break; | |
343 | } | |
344 | } | |
345 | ||
4c7da06f MP |
346 | dm_bm_unlock(b); |
347 | ||
348 | return 0; | |
eec40579 JT |
349 | } |
350 | ||
351 | /*----------------------------------------------------------------*/ | |
352 | ||
353 | static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) | |
354 | { | |
355 | disk->nr_bits = cpu_to_le32(core->nr_bits); | |
356 | disk->root = cpu_to_le64(core->root); | |
357 | } | |
358 | ||
359 | static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) | |
360 | { | |
361 | core->nr_bits = le32_to_cpu(disk->nr_bits); | |
362 | core->root = le64_to_cpu(disk->root); | |
363 | } | |
364 | ||
365 | static void ws_inc(void *context, const void *value) | |
366 | { | |
367 | struct era_metadata *md = context; | |
368 | struct writeset_disk ws_d; | |
369 | dm_block_t b; | |
370 | ||
371 | memcpy(&ws_d, value, sizeof(ws_d)); | |
372 | b = le64_to_cpu(ws_d.root); | |
373 | ||
374 | dm_tm_inc(md->tm, b); | |
375 | } | |
376 | ||
377 | static void ws_dec(void *context, const void *value) | |
378 | { | |
379 | struct era_metadata *md = context; | |
380 | struct writeset_disk ws_d; | |
381 | dm_block_t b; | |
382 | ||
383 | memcpy(&ws_d, value, sizeof(ws_d)); | |
384 | b = le64_to_cpu(ws_d.root); | |
385 | ||
386 | dm_bitset_del(&md->bitset_info, b); | |
387 | } | |
388 | ||
389 | static int ws_eq(void *context, const void *value1, const void *value2) | |
390 | { | |
391 | return !memcmp(value1, value2, sizeof(struct writeset_metadata)); | |
392 | } | |
393 | ||
394 | /*----------------------------------------------------------------*/ | |
395 | ||
396 | static void setup_writeset_tree_info(struct era_metadata *md) | |
397 | { | |
398 | struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; | |
399 | md->writeset_tree_info.tm = md->tm; | |
400 | md->writeset_tree_info.levels = 1; | |
401 | vt->context = md; | |
402 | vt->size = sizeof(struct writeset_disk); | |
403 | vt->inc = ws_inc; | |
404 | vt->dec = ws_dec; | |
405 | vt->equal = ws_eq; | |
406 | } | |
407 | ||
408 | static void setup_era_array_info(struct era_metadata *md) | |
409 | ||
410 | { | |
411 | struct dm_btree_value_type vt; | |
412 | vt.context = NULL; | |
413 | vt.size = sizeof(__le32); | |
414 | vt.inc = NULL; | |
415 | vt.dec = NULL; | |
416 | vt.equal = NULL; | |
417 | ||
418 | dm_array_info_init(&md->era_array_info, md->tm, &vt); | |
419 | } | |
420 | ||
421 | static void setup_infos(struct era_metadata *md) | |
422 | { | |
423 | dm_disk_bitset_init(md->tm, &md->bitset_info); | |
424 | setup_writeset_tree_info(md); | |
425 | setup_era_array_info(md); | |
426 | } | |
427 | ||
428 | /*----------------------------------------------------------------*/ | |
429 | ||
430 | static int create_fresh_metadata(struct era_metadata *md) | |
431 | { | |
432 | int r; | |
433 | ||
434 | r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION, | |
435 | &md->tm, &md->sm); | |
436 | if (r < 0) { | |
437 | DMERR("dm_tm_create_with_sm failed"); | |
438 | return r; | |
439 | } | |
440 | ||
441 | setup_infos(md); | |
442 | ||
443 | r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root); | |
444 | if (r) { | |
445 | DMERR("couldn't create new writeset tree"); | |
446 | goto bad; | |
447 | } | |
448 | ||
449 | r = dm_array_empty(&md->era_array_info, &md->era_array_root); | |
450 | if (r) { | |
451 | DMERR("couldn't create era array"); | |
452 | goto bad; | |
453 | } | |
454 | ||
455 | return 0; | |
456 | ||
457 | bad: | |
458 | dm_sm_destroy(md->sm); | |
459 | dm_tm_destroy(md->tm); | |
460 | ||
461 | return r; | |
462 | } | |
463 | ||
5a32083d JT |
464 | static int save_sm_root(struct era_metadata *md) |
465 | { | |
466 | int r; | |
467 | size_t metadata_len; | |
468 | ||
469 | r = dm_sm_root_size(md->sm, &metadata_len); | |
470 | if (r < 0) | |
471 | return r; | |
472 | ||
473 | return dm_sm_copy_root(md->sm, &md->metadata_space_map_root, | |
474 | metadata_len); | |
475 | } | |
476 | ||
477 | static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) | |
478 | { | |
479 | memcpy(&disk->metadata_space_map_root, | |
480 | &md->metadata_space_map_root, | |
481 | sizeof(md->metadata_space_map_root)); | |
482 | } | |
483 | ||
eec40579 JT |
484 | /* |
485 | * Writes a superblock, including the static fields that don't get updated | |
486 | * with every commit (possible optimisation here). 'md' should be fully | |
487 | * constructed when this is called. | |
488 | */ | |
5a32083d | 489 | static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) |
eec40579 | 490 | { |
eec40579 JT |
491 | disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); |
492 | disk->flags = cpu_to_le32(0ul); | |
493 | ||
494 | /* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ | |
495 | memset(disk->uuid, 0, sizeof(disk->uuid)); | |
496 | disk->version = cpu_to_le32(MAX_ERA_VERSION); | |
497 | ||
5a32083d | 498 | copy_sm_root(md, disk); |
eec40579 JT |
499 | |
500 | disk->data_block_size = cpu_to_le32(md->block_size); | |
501 | disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); | |
502 | disk->nr_blocks = cpu_to_le32(md->nr_blocks); | |
503 | disk->current_era = cpu_to_le32(md->current_era); | |
504 | ||
505 | ws_pack(&md->current_writeset->md, &disk->current_writeset); | |
506 | disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); | |
507 | disk->era_array_root = cpu_to_le64(md->era_array_root); | |
508 | disk->metadata_snap = cpu_to_le64(md->metadata_snap); | |
eec40579 JT |
509 | } |
510 | ||
511 | static int write_superblock(struct era_metadata *md) | |
512 | { | |
513 | int r; | |
514 | struct dm_block *sblock; | |
515 | struct superblock_disk *disk; | |
516 | ||
5a32083d JT |
517 | r = save_sm_root(md); |
518 | if (r) { | |
519 | DMERR("%s: save_sm_root failed", __func__); | |
520 | return r; | |
521 | } | |
522 | ||
eec40579 JT |
523 | r = superblock_lock_zero(md, &sblock); |
524 | if (r) | |
525 | return r; | |
526 | ||
527 | disk = dm_block_data(sblock); | |
5a32083d | 528 | prepare_superblock(md, disk); |
eec40579 JT |
529 | |
530 | return dm_tm_commit(md->tm, sblock); | |
531 | } | |
532 | ||
533 | /* | |
534 | * Assumes block_size and the infos are set. | |
535 | */ | |
536 | static int format_metadata(struct era_metadata *md) | |
537 | { | |
538 | int r; | |
539 | ||
540 | r = create_fresh_metadata(md); | |
541 | if (r) | |
542 | return r; | |
543 | ||
544 | r = write_superblock(md); | |
545 | if (r) { | |
546 | dm_sm_destroy(md->sm); | |
547 | dm_tm_destroy(md->tm); | |
548 | return r; | |
549 | } | |
550 | ||
551 | return 0; | |
552 | } | |
553 | ||
554 | static int open_metadata(struct era_metadata *md) | |
555 | { | |
556 | int r; | |
557 | struct dm_block *sblock; | |
558 | struct superblock_disk *disk; | |
559 | ||
560 | r = superblock_read_lock(md, &sblock); | |
561 | if (r) { | |
562 | DMERR("couldn't read_lock superblock"); | |
563 | return r; | |
564 | } | |
565 | ||
566 | disk = dm_block_data(sblock); | |
567 | r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, | |
568 | disk->metadata_space_map_root, | |
569 | sizeof(disk->metadata_space_map_root), | |
570 | &md->tm, &md->sm); | |
571 | if (r) { | |
572 | DMERR("dm_tm_open_with_sm failed"); | |
573 | goto bad; | |
574 | } | |
575 | ||
576 | setup_infos(md); | |
577 | ||
578 | md->block_size = le32_to_cpu(disk->data_block_size); | |
579 | md->nr_blocks = le32_to_cpu(disk->nr_blocks); | |
580 | md->current_era = le32_to_cpu(disk->current_era); | |
581 | ||
582 | md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); | |
583 | md->era_array_root = le64_to_cpu(disk->era_array_root); | |
584 | md->metadata_snap = le64_to_cpu(disk->metadata_snap); | |
585 | md->archived_writesets = true; | |
586 | ||
4c7da06f MP |
587 | dm_bm_unlock(sblock); |
588 | ||
589 | return 0; | |
eec40579 JT |
590 | |
591 | bad: | |
592 | dm_bm_unlock(sblock); | |
593 | return r; | |
594 | } | |
595 | ||
596 | static int open_or_format_metadata(struct era_metadata *md, | |
597 | bool may_format) | |
598 | { | |
599 | int r; | |
600 | bool unformatted = false; | |
601 | ||
602 | r = superblock_all_zeroes(md->bm, &unformatted); | |
603 | if (r) | |
604 | return r; | |
605 | ||
606 | if (unformatted) | |
607 | return may_format ? format_metadata(md) : -EPERM; | |
608 | ||
609 | return open_metadata(md); | |
610 | } | |
611 | ||
612 | static int create_persistent_data_objects(struct era_metadata *md, | |
613 | bool may_format) | |
614 | { | |
615 | int r; | |
616 | ||
617 | md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE, | |
eec40579 JT |
618 | ERA_MAX_CONCURRENT_LOCKS); |
619 | if (IS_ERR(md->bm)) { | |
620 | DMERR("could not create block manager"); | |
621 | return PTR_ERR(md->bm); | |
622 | } | |
623 | ||
624 | r = open_or_format_metadata(md, may_format); | |
625 | if (r) | |
626 | dm_block_manager_destroy(md->bm); | |
627 | ||
628 | return r; | |
629 | } | |
630 | ||
631 | static void destroy_persistent_data_objects(struct era_metadata *md) | |
632 | { | |
633 | dm_sm_destroy(md->sm); | |
634 | dm_tm_destroy(md->tm); | |
635 | dm_block_manager_destroy(md->bm); | |
636 | } | |
637 | ||
638 | /* | |
639 | * This waits until all era_map threads have picked up the new filter. | |
640 | */ | |
641 | static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) | |
642 | { | |
643 | rcu_assign_pointer(md->current_writeset, new_writeset); | |
644 | synchronize_rcu(); | |
645 | } | |
646 | ||
647 | /*---------------------------------------------------------------- | |
648 | * Writesets get 'digested' into the main era array. | |
649 | * | |
650 | * We're using a coroutine here so the worker thread can do the digestion, | |
651 | * thus avoiding synchronisation of the metadata. Digesting a whole | |
652 | * writeset in one go would cause too much latency. | |
653 | *--------------------------------------------------------------*/ | |
654 | struct digest { | |
655 | uint32_t era; | |
656 | unsigned nr_bits, current_bit; | |
657 | struct writeset_metadata writeset; | |
658 | __le32 value; | |
659 | struct dm_disk_bitset info; | |
660 | ||
661 | int (*step)(struct era_metadata *, struct digest *); | |
662 | }; | |
663 | ||
664 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
665 | struct digest *d); | |
666 | ||
667 | static int metadata_digest_remove_writeset(struct era_metadata *md, | |
668 | struct digest *d) | |
669 | { | |
670 | int r; | |
671 | uint64_t key = d->era; | |
672 | ||
673 | r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root, | |
674 | &key, &md->writeset_tree_root); | |
675 | if (r) { | |
676 | DMERR("%s: dm_btree_remove failed", __func__); | |
677 | return r; | |
678 | } | |
679 | ||
680 | d->step = metadata_digest_lookup_writeset; | |
681 | return 0; | |
682 | } | |
683 | ||
684 | #define INSERTS_PER_STEP 100 | |
685 | ||
686 | static int metadata_digest_transcribe_writeset(struct era_metadata *md, | |
687 | struct digest *d) | |
688 | { | |
689 | int r; | |
690 | bool marked; | |
691 | unsigned b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); | |
692 | ||
693 | for (b = d->current_bit; b < e; b++) { | |
694 | r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked); | |
695 | if (r) { | |
696 | DMERR("%s: writeset_marked_on_disk failed", __func__); | |
697 | return r; | |
698 | } | |
699 | ||
700 | if (!marked) | |
701 | continue; | |
702 | ||
703 | __dm_bless_for_disk(&d->value); | |
704 | r = dm_array_set_value(&md->era_array_info, md->era_array_root, | |
705 | b, &d->value, &md->era_array_root); | |
706 | if (r) { | |
707 | DMERR("%s: dm_array_set_value failed", __func__); | |
708 | return r; | |
709 | } | |
710 | } | |
711 | ||
712 | if (b == d->nr_bits) | |
713 | d->step = metadata_digest_remove_writeset; | |
714 | else | |
715 | d->current_bit = b; | |
716 | ||
717 | return 0; | |
718 | } | |
719 | ||
720 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
721 | struct digest *d) | |
722 | { | |
723 | int r; | |
724 | uint64_t key; | |
725 | struct writeset_disk disk; | |
726 | ||
727 | r = dm_btree_find_lowest_key(&md->writeset_tree_info, | |
728 | md->writeset_tree_root, &key); | |
729 | if (r < 0) | |
730 | return r; | |
731 | ||
732 | d->era = key; | |
733 | ||
734 | r = dm_btree_lookup(&md->writeset_tree_info, | |
735 | md->writeset_tree_root, &key, &disk); | |
736 | if (r) { | |
737 | if (r == -ENODATA) { | |
738 | d->step = NULL; | |
739 | return 0; | |
740 | } | |
741 | ||
742 | DMERR("%s: dm_btree_lookup failed", __func__); | |
743 | return r; | |
744 | } | |
745 | ||
746 | ws_unpack(&disk, &d->writeset); | |
747 | d->value = cpu_to_le32(key); | |
748 | ||
749 | d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); | |
750 | d->current_bit = 0; | |
751 | d->step = metadata_digest_transcribe_writeset; | |
752 | ||
753 | return 0; | |
754 | } | |
755 | ||
756 | static int metadata_digest_start(struct era_metadata *md, struct digest *d) | |
757 | { | |
758 | if (d->step) | |
759 | return 0; | |
760 | ||
761 | memset(d, 0, sizeof(*d)); | |
762 | ||
763 | /* | |
764 | * We initialise another bitset info to avoid any caching side | |
765 | * effects with the previous one. | |
766 | */ | |
767 | dm_disk_bitset_init(md->tm, &d->info); | |
768 | d->step = metadata_digest_lookup_writeset; | |
769 | ||
770 | return 0; | |
771 | } | |
772 | ||
773 | /*---------------------------------------------------------------- | |
774 | * High level metadata interface. Target methods should use these, and not | |
775 | * the lower level ones. | |
776 | *--------------------------------------------------------------*/ | |
777 | static struct era_metadata *metadata_open(struct block_device *bdev, | |
778 | sector_t block_size, | |
779 | bool may_format) | |
780 | { | |
781 | int r; | |
782 | struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL); | |
783 | ||
784 | if (!md) | |
785 | return NULL; | |
786 | ||
787 | md->bdev = bdev; | |
788 | md->block_size = block_size; | |
789 | ||
790 | md->writesets[0].md.root = INVALID_WRITESET_ROOT; | |
791 | md->writesets[1].md.root = INVALID_WRITESET_ROOT; | |
792 | md->current_writeset = &md->writesets[0]; | |
793 | ||
794 | r = create_persistent_data_objects(md, may_format); | |
795 | if (r) { | |
796 | kfree(md); | |
797 | return ERR_PTR(r); | |
798 | } | |
799 | ||
800 | return md; | |
801 | } | |
802 | ||
803 | static void metadata_close(struct era_metadata *md) | |
804 | { | |
805 | destroy_persistent_data_objects(md); | |
806 | kfree(md); | |
807 | } | |
808 | ||
809 | static bool valid_nr_blocks(dm_block_t n) | |
810 | { | |
811 | /* | |
812 | * dm_bitset restricts us to 2^32. test_bit & co. restrict us | |
813 | * further to 2^31 - 1 | |
814 | */ | |
815 | return n < (1ull << 31); | |
816 | } | |
817 | ||
818 | static int metadata_resize(struct era_metadata *md, void *arg) | |
819 | { | |
820 | int r; | |
821 | dm_block_t *new_size = arg; | |
822 | __le32 value; | |
823 | ||
824 | if (!valid_nr_blocks(*new_size)) { | |
825 | DMERR("Invalid number of origin blocks %llu", | |
826 | (unsigned long long) *new_size); | |
827 | return -EINVAL; | |
828 | } | |
829 | ||
830 | writeset_free(&md->writesets[0]); | |
831 | writeset_free(&md->writesets[1]); | |
832 | ||
833 | r = writeset_alloc(&md->writesets[0], *new_size); | |
834 | if (r) { | |
835 | DMERR("%s: writeset_alloc failed for writeset 0", __func__); | |
836 | return r; | |
837 | } | |
838 | ||
839 | r = writeset_alloc(&md->writesets[1], *new_size); | |
840 | if (r) { | |
841 | DMERR("%s: writeset_alloc failed for writeset 1", __func__); | |
842 | return r; | |
843 | } | |
844 | ||
845 | value = cpu_to_le32(0u); | |
846 | __dm_bless_for_disk(&value); | |
847 | r = dm_array_resize(&md->era_array_info, md->era_array_root, | |
848 | md->nr_blocks, *new_size, | |
849 | &value, &md->era_array_root); | |
850 | if (r) { | |
851 | DMERR("%s: dm_array_resize failed", __func__); | |
852 | return r; | |
853 | } | |
854 | ||
855 | md->nr_blocks = *new_size; | |
856 | return 0; | |
857 | } | |
858 | ||
859 | static int metadata_era_archive(struct era_metadata *md) | |
860 | { | |
861 | int r; | |
862 | uint64_t keys[1]; | |
863 | struct writeset_disk value; | |
864 | ||
865 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, | |
866 | &md->current_writeset->md.root); | |
867 | if (r) { | |
868 | DMERR("%s: dm_bitset_flush failed", __func__); | |
869 | return r; | |
870 | } | |
871 | ||
872 | ws_pack(&md->current_writeset->md, &value); | |
873 | md->current_writeset->md.root = INVALID_WRITESET_ROOT; | |
874 | ||
875 | keys[0] = md->current_era; | |
876 | __dm_bless_for_disk(&value); | |
877 | r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, | |
878 | keys, &value, &md->writeset_tree_root); | |
879 | if (r) { | |
880 | DMERR("%s: couldn't insert writeset into btree", __func__); | |
881 | /* FIXME: fail mode */ | |
882 | return r; | |
883 | } | |
884 | ||
885 | md->archived_writesets = true; | |
886 | ||
887 | return 0; | |
888 | } | |
889 | ||
890 | static struct writeset *next_writeset(struct era_metadata *md) | |
891 | { | |
892 | return (md->current_writeset == &md->writesets[0]) ? | |
893 | &md->writesets[1] : &md->writesets[0]; | |
894 | } | |
895 | ||
896 | static int metadata_new_era(struct era_metadata *md) | |
897 | { | |
898 | int r; | |
899 | struct writeset *new_writeset = next_writeset(md); | |
900 | ||
901 | r = writeset_init(&md->bitset_info, new_writeset); | |
902 | if (r) { | |
903 | DMERR("%s: writeset_init failed", __func__); | |
904 | return r; | |
905 | } | |
906 | ||
907 | swap_writeset(md, new_writeset); | |
908 | md->current_era++; | |
909 | ||
910 | return 0; | |
911 | } | |
912 | ||
913 | static int metadata_era_rollover(struct era_metadata *md) | |
914 | { | |
915 | int r; | |
916 | ||
917 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { | |
918 | r = metadata_era_archive(md); | |
919 | if (r) { | |
920 | DMERR("%s: metadata_archive_era failed", __func__); | |
921 | /* FIXME: fail mode? */ | |
922 | return r; | |
923 | } | |
924 | } | |
925 | ||
926 | r = metadata_new_era(md); | |
927 | if (r) { | |
928 | DMERR("%s: new era failed", __func__); | |
929 | /* FIXME: fail mode */ | |
930 | return r; | |
931 | } | |
932 | ||
933 | return 0; | |
934 | } | |
935 | ||
936 | static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) | |
937 | { | |
938 | bool r; | |
939 | struct writeset *ws; | |
940 | ||
941 | rcu_read_lock(); | |
942 | ws = rcu_dereference(md->current_writeset); | |
943 | r = writeset_marked(ws, block); | |
944 | rcu_read_unlock(); | |
945 | ||
946 | return r; | |
947 | } | |
948 | ||
949 | static int metadata_commit(struct era_metadata *md) | |
950 | { | |
951 | int r; | |
952 | struct dm_block *sblock; | |
953 | ||
954 | if (md->current_writeset->md.root != SUPERBLOCK_LOCATION) { | |
955 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, | |
956 | &md->current_writeset->md.root); | |
957 | if (r) { | |
958 | DMERR("%s: bitset flush failed", __func__); | |
959 | return r; | |
960 | } | |
961 | } | |
962 | ||
117aceb0 | 963 | r = dm_tm_pre_commit(md->tm); |
5a32083d | 964 | if (r) { |
117aceb0 | 965 | DMERR("%s: pre commit failed", __func__); |
5a32083d JT |
966 | return r; |
967 | } | |
968 | ||
117aceb0 | 969 | r = save_sm_root(md); |
eec40579 | 970 | if (r) { |
117aceb0 | 971 | DMERR("%s: save_sm_root failed", __func__); |
eec40579 JT |
972 | return r; |
973 | } | |
974 | ||
975 | r = superblock_lock(md, &sblock); | |
976 | if (r) { | |
977 | DMERR("%s: superblock lock failed", __func__); | |
978 | return r; | |
979 | } | |
980 | ||
5a32083d | 981 | prepare_superblock(md, dm_block_data(sblock)); |
eec40579 JT |
982 | |
983 | return dm_tm_commit(md->tm, sblock); | |
984 | } | |
985 | ||
986 | static int metadata_checkpoint(struct era_metadata *md) | |
987 | { | |
988 | /* | |
989 | * For now we just rollover, but later I want to put a check in to | |
990 | * avoid this if the filter is still pretty fresh. | |
991 | */ | |
992 | return metadata_era_rollover(md); | |
993 | } | |
994 | ||
995 | /* | |
996 | * Metadata snapshots allow userland to access era data. | |
997 | */ | |
998 | static int metadata_take_snap(struct era_metadata *md) | |
999 | { | |
1000 | int r, inc; | |
1001 | struct dm_block *clone; | |
1002 | ||
1003 | if (md->metadata_snap != SUPERBLOCK_LOCATION) { | |
1004 | DMERR("%s: metadata snapshot already exists", __func__); | |
1005 | return -EINVAL; | |
1006 | } | |
1007 | ||
1008 | r = metadata_era_rollover(md); | |
1009 | if (r) { | |
1010 | DMERR("%s: era rollover failed", __func__); | |
1011 | return r; | |
1012 | } | |
1013 | ||
1014 | r = metadata_commit(md); | |
1015 | if (r) { | |
1016 | DMERR("%s: pre commit failed", __func__); | |
1017 | return r; | |
1018 | } | |
1019 | ||
1020 | r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); | |
1021 | if (r) { | |
1022 | DMERR("%s: couldn't increment superblock", __func__); | |
1023 | return r; | |
1024 | } | |
1025 | ||
1026 | r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, | |
1027 | &sb_validator, &clone, &inc); | |
1028 | if (r) { | |
1029 | DMERR("%s: couldn't shadow superblock", __func__); | |
1030 | dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); | |
1031 | return r; | |
1032 | } | |
1033 | BUG_ON(!inc); | |
1034 | ||
1035 | r = dm_sm_inc_block(md->sm, md->writeset_tree_root); | |
1036 | if (r) { | |
1037 | DMERR("%s: couldn't inc writeset tree root", __func__); | |
1038 | dm_tm_unlock(md->tm, clone); | |
1039 | return r; | |
1040 | } | |
1041 | ||
1042 | r = dm_sm_inc_block(md->sm, md->era_array_root); | |
1043 | if (r) { | |
1044 | DMERR("%s: couldn't inc era tree root", __func__); | |
1045 | dm_sm_dec_block(md->sm, md->writeset_tree_root); | |
1046 | dm_tm_unlock(md->tm, clone); | |
1047 | return r; | |
1048 | } | |
1049 | ||
1050 | md->metadata_snap = dm_block_location(clone); | |
1051 | ||
4c7da06f | 1052 | dm_tm_unlock(md->tm, clone); |
eec40579 JT |
1053 | |
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | static int metadata_drop_snap(struct era_metadata *md) | |
1058 | { | |
1059 | int r; | |
1060 | dm_block_t location; | |
1061 | struct dm_block *clone; | |
1062 | struct superblock_disk *disk; | |
1063 | ||
1064 | if (md->metadata_snap == SUPERBLOCK_LOCATION) { | |
1065 | DMERR("%s: no snap to drop", __func__); | |
1066 | return -EINVAL; | |
1067 | } | |
1068 | ||
1069 | r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); | |
1070 | if (r) { | |
1071 | DMERR("%s: couldn't read lock superblock clone", __func__); | |
1072 | return r; | |
1073 | } | |
1074 | ||
1075 | /* | |
1076 | * Whatever happens now we'll commit with no record of the metadata | |
1077 | * snap. | |
1078 | */ | |
1079 | md->metadata_snap = SUPERBLOCK_LOCATION; | |
1080 | ||
1081 | disk = dm_block_data(clone); | |
1082 | r = dm_btree_del(&md->writeset_tree_info, | |
1083 | le64_to_cpu(disk->writeset_tree_root)); | |
1084 | if (r) { | |
1085 | DMERR("%s: error deleting writeset tree clone", __func__); | |
1086 | dm_tm_unlock(md->tm, clone); | |
1087 | return r; | |
1088 | } | |
1089 | ||
1090 | r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); | |
1091 | if (r) { | |
1092 | DMERR("%s: error deleting era array clone", __func__); | |
1093 | dm_tm_unlock(md->tm, clone); | |
1094 | return r; | |
1095 | } | |
1096 | ||
1097 | location = dm_block_location(clone); | |
1098 | dm_tm_unlock(md->tm, clone); | |
1099 | ||
1100 | return dm_sm_dec_block(md->sm, location); | |
1101 | } | |
1102 | ||
1103 | struct metadata_stats { | |
1104 | dm_block_t used; | |
1105 | dm_block_t total; | |
1106 | dm_block_t snap; | |
1107 | uint32_t era; | |
1108 | }; | |
1109 | ||
1110 | static int metadata_get_stats(struct era_metadata *md, void *ptr) | |
1111 | { | |
1112 | int r; | |
1113 | struct metadata_stats *s = ptr; | |
1114 | dm_block_t nr_free, nr_total; | |
1115 | ||
1116 | r = dm_sm_get_nr_free(md->sm, &nr_free); | |
1117 | if (r) { | |
1118 | DMERR("dm_sm_get_nr_free returned %d", r); | |
1119 | return r; | |
1120 | } | |
1121 | ||
1122 | r = dm_sm_get_nr_blocks(md->sm, &nr_total); | |
1123 | if (r) { | |
1124 | DMERR("dm_pool_get_metadata_dev_size returned %d", r); | |
1125 | return r; | |
1126 | } | |
1127 | ||
1128 | s->used = nr_total - nr_free; | |
1129 | s->total = nr_total; | |
1130 | s->snap = md->metadata_snap; | |
1131 | s->era = md->current_era; | |
1132 | ||
1133 | return 0; | |
1134 | } | |
1135 | ||
1136 | /*----------------------------------------------------------------*/ | |
1137 | ||
1138 | struct era { | |
1139 | struct dm_target *ti; | |
1140 | struct dm_target_callbacks callbacks; | |
1141 | ||
1142 | struct dm_dev *metadata_dev; | |
1143 | struct dm_dev *origin_dev; | |
1144 | ||
1145 | dm_block_t nr_blocks; | |
1146 | uint32_t sectors_per_block; | |
1147 | int sectors_per_block_shift; | |
1148 | struct era_metadata *md; | |
1149 | ||
1150 | struct workqueue_struct *wq; | |
1151 | struct work_struct worker; | |
1152 | ||
1153 | spinlock_t deferred_lock; | |
1154 | struct bio_list deferred_bios; | |
1155 | ||
1156 | spinlock_t rpc_lock; | |
1157 | struct list_head rpc_calls; | |
1158 | ||
1159 | struct digest digest; | |
1160 | atomic_t suspended; | |
1161 | }; | |
1162 | ||
1163 | struct rpc { | |
1164 | struct list_head list; | |
1165 | ||
1166 | int (*fn0)(struct era_metadata *); | |
1167 | int (*fn1)(struct era_metadata *, void *); | |
1168 | void *arg; | |
1169 | int result; | |
1170 | ||
1171 | struct completion complete; | |
1172 | }; | |
1173 | ||
1174 | /*---------------------------------------------------------------- | |
1175 | * Remapping. | |
1176 | *---------------------------------------------------------------*/ | |
1177 | static bool block_size_is_power_of_two(struct era *era) | |
1178 | { | |
1179 | return era->sectors_per_block_shift >= 0; | |
1180 | } | |
1181 | ||
1182 | static dm_block_t get_block(struct era *era, struct bio *bio) | |
1183 | { | |
1184 | sector_t block_nr = bio->bi_iter.bi_sector; | |
1185 | ||
1186 | if (!block_size_is_power_of_two(era)) | |
1187 | (void) sector_div(block_nr, era->sectors_per_block); | |
1188 | else | |
1189 | block_nr >>= era->sectors_per_block_shift; | |
1190 | ||
1191 | return block_nr; | |
1192 | } | |
1193 | ||
1194 | static void remap_to_origin(struct era *era, struct bio *bio) | |
1195 | { | |
74d46992 | 1196 | bio_set_dev(bio, era->origin_dev->bdev); |
eec40579 JT |
1197 | } |
1198 | ||
1199 | /*---------------------------------------------------------------- | |
1200 | * Worker thread | |
1201 | *--------------------------------------------------------------*/ | |
1202 | static void wake_worker(struct era *era) | |
1203 | { | |
1204 | if (!atomic_read(&era->suspended)) | |
1205 | queue_work(era->wq, &era->worker); | |
1206 | } | |
1207 | ||
1208 | static void process_old_eras(struct era *era) | |
1209 | { | |
1210 | int r; | |
1211 | ||
1212 | if (!era->digest.step) | |
1213 | return; | |
1214 | ||
1215 | r = era->digest.step(era->md, &era->digest); | |
1216 | if (r < 0) { | |
1217 | DMERR("%s: digest step failed, stopping digestion", __func__); | |
1218 | era->digest.step = NULL; | |
1219 | ||
1220 | } else if (era->digest.step) | |
1221 | wake_worker(era); | |
1222 | } | |
1223 | ||
1224 | static void process_deferred_bios(struct era *era) | |
1225 | { | |
1226 | int r; | |
1227 | struct bio_list deferred_bios, marked_bios; | |
1228 | struct bio *bio; | |
1229 | bool commit_needed = false; | |
1230 | bool failed = false; | |
1231 | ||
1232 | bio_list_init(&deferred_bios); | |
1233 | bio_list_init(&marked_bios); | |
1234 | ||
1235 | spin_lock(&era->deferred_lock); | |
1236 | bio_list_merge(&deferred_bios, &era->deferred_bios); | |
1237 | bio_list_init(&era->deferred_bios); | |
1238 | spin_unlock(&era->deferred_lock); | |
1239 | ||
1240 | while ((bio = bio_list_pop(&deferred_bios))) { | |
1241 | r = writeset_test_and_set(&era->md->bitset_info, | |
1242 | era->md->current_writeset, | |
1243 | get_block(era, bio)); | |
1244 | if (r < 0) { | |
1245 | /* | |
1246 | * This is bad news, we need to rollback. | |
1247 | * FIXME: finish. | |
1248 | */ | |
1249 | failed = true; | |
1250 | ||
1251 | } else if (r == 0) | |
1252 | commit_needed = true; | |
1253 | ||
1254 | bio_list_add(&marked_bios, bio); | |
1255 | } | |
1256 | ||
1257 | if (commit_needed) { | |
1258 | r = metadata_commit(era->md); | |
1259 | if (r) | |
1260 | failed = true; | |
1261 | } | |
1262 | ||
1263 | if (failed) | |
1264 | while ((bio = bio_list_pop(&marked_bios))) | |
1265 | bio_io_error(bio); | |
1266 | else | |
1267 | while ((bio = bio_list_pop(&marked_bios))) | |
1268 | generic_make_request(bio); | |
1269 | } | |
1270 | ||
1271 | static void process_rpc_calls(struct era *era) | |
1272 | { | |
1273 | int r; | |
1274 | bool need_commit = false; | |
1275 | struct list_head calls; | |
1276 | struct rpc *rpc, *tmp; | |
1277 | ||
1278 | INIT_LIST_HEAD(&calls); | |
1279 | spin_lock(&era->rpc_lock); | |
1280 | list_splice_init(&era->rpc_calls, &calls); | |
1281 | spin_unlock(&era->rpc_lock); | |
1282 | ||
1283 | list_for_each_entry_safe(rpc, tmp, &calls, list) { | |
1284 | rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); | |
1285 | need_commit = true; | |
1286 | } | |
1287 | ||
1288 | if (need_commit) { | |
1289 | r = metadata_commit(era->md); | |
1290 | if (r) | |
1291 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1292 | rpc->result = r; | |
1293 | } | |
1294 | ||
1295 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1296 | complete(&rpc->complete); | |
1297 | } | |
1298 | ||
1299 | static void kick_off_digest(struct era *era) | |
1300 | { | |
1301 | if (era->md->archived_writesets) { | |
1302 | era->md->archived_writesets = false; | |
1303 | metadata_digest_start(era->md, &era->digest); | |
1304 | } | |
1305 | } | |
1306 | ||
1307 | static void do_work(struct work_struct *ws) | |
1308 | { | |
1309 | struct era *era = container_of(ws, struct era, worker); | |
1310 | ||
1311 | kick_off_digest(era); | |
1312 | process_old_eras(era); | |
1313 | process_deferred_bios(era); | |
1314 | process_rpc_calls(era); | |
1315 | } | |
1316 | ||
1317 | static void defer_bio(struct era *era, struct bio *bio) | |
1318 | { | |
1319 | spin_lock(&era->deferred_lock); | |
1320 | bio_list_add(&era->deferred_bios, bio); | |
1321 | spin_unlock(&era->deferred_lock); | |
1322 | ||
1323 | wake_worker(era); | |
1324 | } | |
1325 | ||
1326 | /* | |
1327 | * Make an rpc call to the worker to change the metadata. | |
1328 | */ | |
1329 | static int perform_rpc(struct era *era, struct rpc *rpc) | |
1330 | { | |
1331 | rpc->result = 0; | |
1332 | init_completion(&rpc->complete); | |
1333 | ||
1334 | spin_lock(&era->rpc_lock); | |
1335 | list_add(&rpc->list, &era->rpc_calls); | |
1336 | spin_unlock(&era->rpc_lock); | |
1337 | ||
1338 | wake_worker(era); | |
1339 | wait_for_completion(&rpc->complete); | |
1340 | ||
1341 | return rpc->result; | |
1342 | } | |
1343 | ||
1344 | static int in_worker0(struct era *era, int (*fn)(struct era_metadata *)) | |
1345 | { | |
1346 | struct rpc rpc; | |
1347 | rpc.fn0 = fn; | |
1348 | rpc.fn1 = NULL; | |
1349 | ||
1350 | return perform_rpc(era, &rpc); | |
1351 | } | |
1352 | ||
1353 | static int in_worker1(struct era *era, | |
1354 | int (*fn)(struct era_metadata *, void *), void *arg) | |
1355 | { | |
1356 | struct rpc rpc; | |
1357 | rpc.fn0 = NULL; | |
1358 | rpc.fn1 = fn; | |
1359 | rpc.arg = arg; | |
1360 | ||
1361 | return perform_rpc(era, &rpc); | |
1362 | } | |
1363 | ||
1364 | static void start_worker(struct era *era) | |
1365 | { | |
1366 | atomic_set(&era->suspended, 0); | |
1367 | } | |
1368 | ||
1369 | static void stop_worker(struct era *era) | |
1370 | { | |
1371 | atomic_set(&era->suspended, 1); | |
1372 | flush_workqueue(era->wq); | |
1373 | } | |
1374 | ||
1375 | /*---------------------------------------------------------------- | |
1376 | * Target methods | |
1377 | *--------------------------------------------------------------*/ | |
1378 | static int dev_is_congested(struct dm_dev *dev, int bdi_bits) | |
1379 | { | |
1380 | struct request_queue *q = bdev_get_queue(dev->bdev); | |
dc3b17cc | 1381 | return bdi_congested(q->backing_dev_info, bdi_bits); |
eec40579 JT |
1382 | } |
1383 | ||
1384 | static int era_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
1385 | { | |
1386 | struct era *era = container_of(cb, struct era, callbacks); | |
1387 | return dev_is_congested(era->origin_dev, bdi_bits); | |
1388 | } | |
1389 | ||
1390 | static void era_destroy(struct era *era) | |
1391 | { | |
989f26f5 JT |
1392 | if (era->md) |
1393 | metadata_close(era->md); | |
eec40579 JT |
1394 | |
1395 | if (era->wq) | |
1396 | destroy_workqueue(era->wq); | |
1397 | ||
1398 | if (era->origin_dev) | |
1399 | dm_put_device(era->ti, era->origin_dev); | |
1400 | ||
1401 | if (era->metadata_dev) | |
1402 | dm_put_device(era->ti, era->metadata_dev); | |
1403 | ||
1404 | kfree(era); | |
1405 | } | |
1406 | ||
1407 | static dm_block_t calc_nr_blocks(struct era *era) | |
1408 | { | |
1409 | return dm_sector_div_up(era->ti->len, era->sectors_per_block); | |
1410 | } | |
1411 | ||
1412 | static bool valid_block_size(dm_block_t block_size) | |
1413 | { | |
1414 | bool greater_than_zero = block_size > 0; | |
1415 | bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; | |
1416 | ||
1417 | return greater_than_zero && multiple_of_min_block_size; | |
1418 | } | |
1419 | ||
1420 | /* | |
1421 | * <metadata dev> <data dev> <data block size (sectors)> | |
1422 | */ | |
1423 | static int era_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1424 | { | |
1425 | int r; | |
1426 | char dummy; | |
1427 | struct era *era; | |
1428 | struct era_metadata *md; | |
1429 | ||
1430 | if (argc != 3) { | |
1431 | ti->error = "Invalid argument count"; | |
1432 | return -EINVAL; | |
1433 | } | |
1434 | ||
1435 | era = kzalloc(sizeof(*era), GFP_KERNEL); | |
1436 | if (!era) { | |
1437 | ti->error = "Error allocating era structure"; | |
1438 | return -ENOMEM; | |
1439 | } | |
1440 | ||
1441 | era->ti = ti; | |
1442 | ||
1443 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &era->metadata_dev); | |
1444 | if (r) { | |
1445 | ti->error = "Error opening metadata device"; | |
1446 | era_destroy(era); | |
1447 | return -EINVAL; | |
1448 | } | |
1449 | ||
1450 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &era->origin_dev); | |
1451 | if (r) { | |
1452 | ti->error = "Error opening data device"; | |
1453 | era_destroy(era); | |
1454 | return -EINVAL; | |
1455 | } | |
1456 | ||
1457 | r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); | |
1458 | if (r != 1) { | |
1459 | ti->error = "Error parsing block size"; | |
1460 | era_destroy(era); | |
1461 | return -EINVAL; | |
1462 | } | |
1463 | ||
1464 | r = dm_set_target_max_io_len(ti, era->sectors_per_block); | |
1465 | if (r) { | |
1466 | ti->error = "could not set max io len"; | |
1467 | era_destroy(era); | |
1468 | return -EINVAL; | |
1469 | } | |
1470 | ||
1471 | if (!valid_block_size(era->sectors_per_block)) { | |
1472 | ti->error = "Invalid block size"; | |
1473 | era_destroy(era); | |
1474 | return -EINVAL; | |
1475 | } | |
1476 | if (era->sectors_per_block & (era->sectors_per_block - 1)) | |
1477 | era->sectors_per_block_shift = -1; | |
1478 | else | |
1479 | era->sectors_per_block_shift = __ffs(era->sectors_per_block); | |
1480 | ||
1481 | md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); | |
1482 | if (IS_ERR(md)) { | |
1483 | ti->error = "Error reading metadata"; | |
1484 | era_destroy(era); | |
1485 | return PTR_ERR(md); | |
1486 | } | |
1487 | era->md = md; | |
1488 | ||
1489 | era->nr_blocks = calc_nr_blocks(era); | |
1490 | ||
1491 | r = metadata_resize(era->md, &era->nr_blocks); | |
1492 | if (r) { | |
1493 | ti->error = "couldn't resize metadata"; | |
1494 | era_destroy(era); | |
1495 | return -ENOMEM; | |
1496 | } | |
1497 | ||
1498 | era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
1499 | if (!era->wq) { | |
1500 | ti->error = "could not create workqueue for metadata object"; | |
1501 | era_destroy(era); | |
1502 | return -ENOMEM; | |
1503 | } | |
1504 | INIT_WORK(&era->worker, do_work); | |
1505 | ||
1506 | spin_lock_init(&era->deferred_lock); | |
1507 | bio_list_init(&era->deferred_bios); | |
1508 | ||
1509 | spin_lock_init(&era->rpc_lock); | |
1510 | INIT_LIST_HEAD(&era->rpc_calls); | |
1511 | ||
1512 | ti->private = era; | |
1513 | ti->num_flush_bios = 1; | |
1514 | ti->flush_supported = true; | |
1515 | ||
1516 | ti->num_discard_bios = 1; | |
eec40579 JT |
1517 | era->callbacks.congested_fn = era_is_congested; |
1518 | dm_table_add_target_callbacks(ti->table, &era->callbacks); | |
1519 | ||
1520 | return 0; | |
1521 | } | |
1522 | ||
1523 | static void era_dtr(struct dm_target *ti) | |
1524 | { | |
1525 | era_destroy(ti->private); | |
1526 | } | |
1527 | ||
1528 | static int era_map(struct dm_target *ti, struct bio *bio) | |
1529 | { | |
1530 | struct era *era = ti->private; | |
1531 | dm_block_t block = get_block(era, bio); | |
1532 | ||
1533 | /* | |
1534 | * All bios get remapped to the origin device. We do this now, but | |
1535 | * it may not get issued until later. Depending on whether the | |
1536 | * block is marked in this era. | |
1537 | */ | |
1538 | remap_to_origin(era, bio); | |
1539 | ||
1540 | /* | |
28a8f0d3 | 1541 | * REQ_PREFLUSH bios carry no data, so we're not interested in them. |
eec40579 | 1542 | */ |
1eff9d32 | 1543 | if (!(bio->bi_opf & REQ_PREFLUSH) && |
eec40579 JT |
1544 | (bio_data_dir(bio) == WRITE) && |
1545 | !metadata_current_marked(era->md, block)) { | |
1546 | defer_bio(era, bio); | |
1547 | return DM_MAPIO_SUBMITTED; | |
1548 | } | |
1549 | ||
1550 | return DM_MAPIO_REMAPPED; | |
1551 | } | |
1552 | ||
1553 | static void era_postsuspend(struct dm_target *ti) | |
1554 | { | |
1555 | int r; | |
1556 | struct era *era = ti->private; | |
1557 | ||
1558 | r = in_worker0(era, metadata_era_archive); | |
1559 | if (r) { | |
1560 | DMERR("%s: couldn't archive current era", __func__); | |
1561 | /* FIXME: fail mode */ | |
1562 | } | |
1563 | ||
1564 | stop_worker(era); | |
1565 | } | |
1566 | ||
1567 | static int era_preresume(struct dm_target *ti) | |
1568 | { | |
1569 | int r; | |
1570 | struct era *era = ti->private; | |
1571 | dm_block_t new_size = calc_nr_blocks(era); | |
1572 | ||
1573 | if (era->nr_blocks != new_size) { | |
1574 | r = in_worker1(era, metadata_resize, &new_size); | |
1575 | if (r) | |
1576 | return r; | |
1577 | ||
1578 | era->nr_blocks = new_size; | |
1579 | } | |
1580 | ||
1581 | start_worker(era); | |
1582 | ||
1583 | r = in_worker0(era, metadata_new_era); | |
1584 | if (r) { | |
1585 | DMERR("%s: metadata_era_rollover failed", __func__); | |
1586 | return r; | |
1587 | } | |
1588 | ||
1589 | return 0; | |
1590 | } | |
1591 | ||
1592 | /* | |
1593 | * Status format: | |
1594 | * | |
1595 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> | |
1596 | * <current era> <held metadata root | '-'> | |
1597 | */ | |
1598 | static void era_status(struct dm_target *ti, status_type_t type, | |
1599 | unsigned status_flags, char *result, unsigned maxlen) | |
1600 | { | |
1601 | int r; | |
1602 | struct era *era = ti->private; | |
1603 | ssize_t sz = 0; | |
1604 | struct metadata_stats stats; | |
1605 | char buf[BDEVNAME_SIZE]; | |
1606 | ||
1607 | switch (type) { | |
1608 | case STATUSTYPE_INFO: | |
1609 | r = in_worker1(era, metadata_get_stats, &stats); | |
1610 | if (r) | |
1611 | goto err; | |
1612 | ||
1613 | DMEMIT("%u %llu/%llu %u", | |
1614 | (unsigned) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), | |
1615 | (unsigned long long) stats.used, | |
1616 | (unsigned long long) stats.total, | |
1617 | (unsigned) stats.era); | |
1618 | ||
1619 | if (stats.snap != SUPERBLOCK_LOCATION) | |
1620 | DMEMIT(" %llu", stats.snap); | |
1621 | else | |
1622 | DMEMIT(" -"); | |
1623 | break; | |
1624 | ||
1625 | case STATUSTYPE_TABLE: | |
1626 | format_dev_t(buf, era->metadata_dev->bdev->bd_dev); | |
1627 | DMEMIT("%s ", buf); | |
1628 | format_dev_t(buf, era->origin_dev->bdev->bd_dev); | |
1629 | DMEMIT("%s %u", buf, era->sectors_per_block); | |
1630 | break; | |
1631 | } | |
1632 | ||
1633 | return; | |
1634 | ||
1635 | err: | |
1636 | DMEMIT("Error"); | |
1637 | } | |
1638 | ||
1eb5fa84 MS |
1639 | static int era_message(struct dm_target *ti, unsigned argc, char **argv, |
1640 | char *result, unsigned maxlen) | |
eec40579 JT |
1641 | { |
1642 | struct era *era = ti->private; | |
1643 | ||
1644 | if (argc != 1) { | |
1645 | DMERR("incorrect number of message arguments"); | |
1646 | return -EINVAL; | |
1647 | } | |
1648 | ||
1649 | if (!strcasecmp(argv[0], "checkpoint")) | |
1650 | return in_worker0(era, metadata_checkpoint); | |
1651 | ||
1652 | if (!strcasecmp(argv[0], "take_metadata_snap")) | |
1653 | return in_worker0(era, metadata_take_snap); | |
1654 | ||
1655 | if (!strcasecmp(argv[0], "drop_metadata_snap")) | |
1656 | return in_worker0(era, metadata_drop_snap); | |
1657 | ||
1658 | DMERR("unsupported message '%s'", argv[0]); | |
1659 | return -EINVAL; | |
1660 | } | |
1661 | ||
1662 | static sector_t get_dev_size(struct dm_dev *dev) | |
1663 | { | |
1664 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
1665 | } | |
1666 | ||
1667 | static int era_iterate_devices(struct dm_target *ti, | |
1668 | iterate_devices_callout_fn fn, void *data) | |
1669 | { | |
1670 | struct era *era = ti->private; | |
1671 | return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); | |
1672 | } | |
1673 | ||
eec40579 JT |
1674 | static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) |
1675 | { | |
1676 | struct era *era = ti->private; | |
1677 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; | |
1678 | ||
1679 | /* | |
1680 | * If the system-determined stacked limits are compatible with the | |
1681 | * era device's blocksize (io_opt is a factor) do not override them. | |
1682 | */ | |
1683 | if (io_opt_sectors < era->sectors_per_block || | |
1684 | do_div(io_opt_sectors, era->sectors_per_block)) { | |
1685 | blk_limits_io_min(limits, 0); | |
1686 | blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT); | |
1687 | } | |
1688 | } | |
1689 | ||
1690 | /*----------------------------------------------------------------*/ | |
1691 | ||
1692 | static struct target_type era_target = { | |
1693 | .name = "era", | |
1694 | .version = {1, 0, 0}, | |
1695 | .module = THIS_MODULE, | |
1696 | .ctr = era_ctr, | |
1697 | .dtr = era_dtr, | |
1698 | .map = era_map, | |
1699 | .postsuspend = era_postsuspend, | |
1700 | .preresume = era_preresume, | |
1701 | .status = era_status, | |
1702 | .message = era_message, | |
1703 | .iterate_devices = era_iterate_devices, | |
eec40579 JT |
1704 | .io_hints = era_io_hints |
1705 | }; | |
1706 | ||
1707 | static int __init dm_era_init(void) | |
1708 | { | |
1709 | int r; | |
1710 | ||
1711 | r = dm_register_target(&era_target); | |
1712 | if (r) { | |
1713 | DMERR("era target registration failed: %d", r); | |
1714 | return r; | |
1715 | } | |
1716 | ||
1717 | return 0; | |
1718 | } | |
1719 | ||
1720 | static void __exit dm_era_exit(void) | |
1721 | { | |
1722 | dm_unregister_target(&era_target); | |
1723 | } | |
1724 | ||
1725 | module_init(dm_era_init); | |
1726 | module_exit(dm_era_exit); | |
1727 | ||
1728 | MODULE_DESCRIPTION(DM_NAME " era target"); | |
1729 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
1730 | MODULE_LICENSE("GPL"); |