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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); | |
904e6b26 | 50 | ws->bits = NULL; |
eec40579 JT |
51 | } |
52 | ||
53 | static int setup_on_disk_bitset(struct dm_disk_bitset *info, | |
54 | unsigned nr_bits, dm_block_t *root) | |
55 | { | |
56 | int r; | |
57 | ||
58 | r = dm_bitset_empty(info, root); | |
59 | if (r) | |
60 | return r; | |
61 | ||
62 | return dm_bitset_resize(info, *root, 0, nr_bits, false, root); | |
63 | } | |
64 | ||
65 | static size_t bitset_size(unsigned nr_bits) | |
66 | { | |
67 | return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); | |
68 | } | |
69 | ||
70 | /* | |
71 | * Allocates memory for the in core bitset. | |
72 | */ | |
73 | static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) | |
74 | { | |
eec40579 JT |
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 | */ | |
de89afc1 NT |
87 | static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws, |
88 | dm_block_t nr_blocks) | |
eec40579 JT |
89 | { |
90 | int r; | |
91 | ||
de89afc1 | 92 | memset(ws->bits, 0, bitset_size(nr_blocks)); |
eec40579 | 93 | |
de89afc1 | 94 | ws->md.nr_bits = nr_blocks; |
eec40579 JT |
95 | r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root); |
96 | if (r) { | |
97 | DMERR("%s: setup_on_disk_bitset failed", __func__); | |
98 | return r; | |
99 | } | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static bool writeset_marked(struct writeset *ws, dm_block_t block) | |
105 | { | |
106 | return test_bit(block, ws->bits); | |
107 | } | |
108 | ||
109 | static int writeset_marked_on_disk(struct dm_disk_bitset *info, | |
110 | struct writeset_metadata *m, dm_block_t block, | |
111 | bool *result) | |
112 | { | |
113 | dm_block_t old = m->root; | |
114 | ||
115 | /* | |
116 | * The bitset was flushed when it was archived, so we know there'll | |
117 | * be no change to the root. | |
118 | */ | |
119 | int r = dm_bitset_test_bit(info, m->root, block, &m->root, result); | |
120 | if (r) { | |
121 | DMERR("%s: dm_bitset_test_bit failed", __func__); | |
122 | return r; | |
123 | } | |
124 | ||
125 | BUG_ON(m->root != old); | |
126 | ||
127 | return r; | |
128 | } | |
129 | ||
130 | /* | |
131 | * Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. | |
132 | */ | |
133 | static int writeset_test_and_set(struct dm_disk_bitset *info, | |
134 | struct writeset *ws, uint32_t block) | |
135 | { | |
136 | int r; | |
137 | ||
2099b145 | 138 | if (!test_bit(block, ws->bits)) { |
eec40579 JT |
139 | r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root); |
140 | if (r) { | |
141 | /* FIXME: fail mode */ | |
142 | return r; | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | return 1; | |
149 | } | |
150 | ||
151 | /*---------------------------------------------------------------- | |
152 | * On disk metadata layout | |
153 | *--------------------------------------------------------------*/ | |
154 | #define SPACE_MAP_ROOT_SIZE 128 | |
155 | #define UUID_LEN 16 | |
156 | ||
157 | struct writeset_disk { | |
158 | __le32 nr_bits; | |
159 | __le64 root; | |
160 | } __packed; | |
161 | ||
162 | struct superblock_disk { | |
163 | __le32 csum; | |
164 | __le32 flags; | |
165 | __le64 blocknr; | |
166 | ||
167 | __u8 uuid[UUID_LEN]; | |
168 | __le64 magic; | |
169 | __le32 version; | |
170 | ||
171 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
172 | ||
173 | __le32 data_block_size; | |
174 | __le32 metadata_block_size; | |
175 | __le32 nr_blocks; | |
176 | ||
177 | __le32 current_era; | |
178 | struct writeset_disk current_writeset; | |
179 | ||
180 | /* | |
181 | * Only these two fields are valid within the metadata snapshot. | |
182 | */ | |
183 | __le64 writeset_tree_root; | |
184 | __le64 era_array_root; | |
185 | ||
186 | __le64 metadata_snap; | |
187 | } __packed; | |
188 | ||
189 | /*---------------------------------------------------------------- | |
190 | * Superblock validation | |
191 | *--------------------------------------------------------------*/ | |
192 | static void sb_prepare_for_write(struct dm_block_validator *v, | |
193 | struct dm_block *b, | |
194 | size_t sb_block_size) | |
195 | { | |
196 | struct superblock_disk *disk = dm_block_data(b); | |
197 | ||
198 | disk->blocknr = cpu_to_le64(dm_block_location(b)); | |
199 | disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
200 | sb_block_size - sizeof(__le32), | |
201 | SUPERBLOCK_CSUM_XOR)); | |
202 | } | |
203 | ||
204 | static int check_metadata_version(struct superblock_disk *disk) | |
205 | { | |
206 | uint32_t metadata_version = le32_to_cpu(disk->version); | |
207 | if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { | |
208 | DMERR("Era metadata version %u found, but only versions between %u and %u supported.", | |
209 | metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); | |
210 | return -EINVAL; | |
211 | } | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
216 | static int sb_check(struct dm_block_validator *v, | |
217 | struct dm_block *b, | |
218 | size_t sb_block_size) | |
219 | { | |
220 | struct superblock_disk *disk = dm_block_data(b); | |
221 | __le32 csum_le; | |
222 | ||
223 | if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { | |
224 | DMERR("sb_check failed: blocknr %llu: wanted %llu", | |
225 | le64_to_cpu(disk->blocknr), | |
226 | (unsigned long long)dm_block_location(b)); | |
227 | return -ENOTBLK; | |
228 | } | |
229 | ||
230 | if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { | |
231 | DMERR("sb_check failed: magic %llu: wanted %llu", | |
232 | le64_to_cpu(disk->magic), | |
233 | (unsigned long long) SUPERBLOCK_MAGIC); | |
234 | return -EILSEQ; | |
235 | } | |
236 | ||
237 | csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, | |
238 | sb_block_size - sizeof(__le32), | |
239 | SUPERBLOCK_CSUM_XOR)); | |
240 | if (csum_le != disk->csum) { | |
241 | DMERR("sb_check failed: csum %u: wanted %u", | |
242 | le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); | |
243 | return -EILSEQ; | |
244 | } | |
245 | ||
246 | return check_metadata_version(disk); | |
247 | } | |
248 | ||
249 | static struct dm_block_validator sb_validator = { | |
250 | .name = "superblock", | |
251 | .prepare_for_write = sb_prepare_for_write, | |
252 | .check = sb_check | |
253 | }; | |
254 | ||
255 | /*---------------------------------------------------------------- | |
256 | * Low level metadata handling | |
257 | *--------------------------------------------------------------*/ | |
258 | #define DM_ERA_METADATA_BLOCK_SIZE 4096 | |
eec40579 JT |
259 | #define ERA_MAX_CONCURRENT_LOCKS 5 |
260 | ||
261 | struct era_metadata { | |
262 | struct block_device *bdev; | |
263 | struct dm_block_manager *bm; | |
264 | struct dm_space_map *sm; | |
265 | struct dm_transaction_manager *tm; | |
266 | ||
267 | dm_block_t block_size; | |
268 | uint32_t nr_blocks; | |
269 | ||
270 | uint32_t current_era; | |
271 | ||
272 | /* | |
273 | * We preallocate 2 writesets. When an era rolls over we | |
274 | * switch between them. This means the allocation is done at | |
275 | * preresume time, rather than on the io path. | |
276 | */ | |
277 | struct writeset writesets[2]; | |
278 | struct writeset *current_writeset; | |
279 | ||
280 | dm_block_t writeset_tree_root; | |
281 | dm_block_t era_array_root; | |
282 | ||
283 | struct dm_disk_bitset bitset_info; | |
284 | struct dm_btree_info writeset_tree_info; | |
285 | struct dm_array_info era_array_info; | |
286 | ||
287 | dm_block_t metadata_snap; | |
288 | ||
289 | /* | |
290 | * A flag that is set whenever a writeset has been archived. | |
291 | */ | |
292 | bool archived_writesets; | |
5a32083d JT |
293 | |
294 | /* | |
295 | * Reading the space map root can fail, so we read it into this | |
296 | * buffer before the superblock is locked and updated. | |
297 | */ | |
298 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
eec40579 JT |
299 | }; |
300 | ||
301 | static int superblock_read_lock(struct era_metadata *md, | |
302 | struct dm_block **sblock) | |
303 | { | |
304 | return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION, | |
305 | &sb_validator, sblock); | |
306 | } | |
307 | ||
308 | static int superblock_lock_zero(struct era_metadata *md, | |
309 | struct dm_block **sblock) | |
310 | { | |
311 | return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION, | |
312 | &sb_validator, sblock); | |
313 | } | |
314 | ||
315 | static int superblock_lock(struct era_metadata *md, | |
316 | struct dm_block **sblock) | |
317 | { | |
318 | return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION, | |
319 | &sb_validator, sblock); | |
320 | } | |
321 | ||
322 | /* FIXME: duplication with cache and thin */ | |
323 | static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result) | |
324 | { | |
325 | int r; | |
326 | unsigned i; | |
327 | struct dm_block *b; | |
328 | __le64 *data_le, zero = cpu_to_le64(0); | |
329 | unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); | |
330 | ||
331 | /* | |
332 | * We can't use a validator here - it may be all zeroes. | |
333 | */ | |
334 | r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b); | |
335 | if (r) | |
336 | return r; | |
337 | ||
338 | data_le = dm_block_data(b); | |
339 | *result = true; | |
340 | for (i = 0; i < sb_block_size; i++) { | |
341 | if (data_le[i] != zero) { | |
342 | *result = false; | |
343 | break; | |
344 | } | |
345 | } | |
346 | ||
4c7da06f MP |
347 | dm_bm_unlock(b); |
348 | ||
349 | return 0; | |
eec40579 JT |
350 | } |
351 | ||
352 | /*----------------------------------------------------------------*/ | |
353 | ||
354 | static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) | |
355 | { | |
356 | disk->nr_bits = cpu_to_le32(core->nr_bits); | |
357 | disk->root = cpu_to_le64(core->root); | |
358 | } | |
359 | ||
360 | static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) | |
361 | { | |
362 | core->nr_bits = le32_to_cpu(disk->nr_bits); | |
363 | core->root = le64_to_cpu(disk->root); | |
364 | } | |
365 | ||
be500ed7 | 366 | static void ws_inc(void *context, const void *value, unsigned count) |
eec40579 JT |
367 | { |
368 | struct era_metadata *md = context; | |
369 | struct writeset_disk ws_d; | |
370 | dm_block_t b; | |
be500ed7 | 371 | unsigned i; |
eec40579 | 372 | |
be500ed7 JT |
373 | for (i = 0; i < count; i++) { |
374 | memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); | |
375 | b = le64_to_cpu(ws_d.root); | |
376 | dm_tm_inc(md->tm, b); | |
377 | } | |
eec40579 JT |
378 | } |
379 | ||
be500ed7 | 380 | static void ws_dec(void *context, const void *value, unsigned count) |
eec40579 JT |
381 | { |
382 | struct era_metadata *md = context; | |
383 | struct writeset_disk ws_d; | |
384 | dm_block_t b; | |
be500ed7 | 385 | unsigned i; |
eec40579 | 386 | |
be500ed7 JT |
387 | for (i = 0; i < count; i++) { |
388 | memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); | |
389 | b = le64_to_cpu(ws_d.root); | |
390 | dm_bitset_del(&md->bitset_info, b); | |
391 | } | |
eec40579 JT |
392 | } |
393 | ||
394 | static int ws_eq(void *context, const void *value1, const void *value2) | |
395 | { | |
64f2d15a | 396 | return !memcmp(value1, value2, sizeof(struct writeset_disk)); |
eec40579 JT |
397 | } |
398 | ||
399 | /*----------------------------------------------------------------*/ | |
400 | ||
401 | static void setup_writeset_tree_info(struct era_metadata *md) | |
402 | { | |
403 | struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; | |
404 | md->writeset_tree_info.tm = md->tm; | |
405 | md->writeset_tree_info.levels = 1; | |
406 | vt->context = md; | |
407 | vt->size = sizeof(struct writeset_disk); | |
408 | vt->inc = ws_inc; | |
409 | vt->dec = ws_dec; | |
410 | vt->equal = ws_eq; | |
411 | } | |
412 | ||
413 | static void setup_era_array_info(struct era_metadata *md) | |
414 | ||
415 | { | |
416 | struct dm_btree_value_type vt; | |
417 | vt.context = NULL; | |
418 | vt.size = sizeof(__le32); | |
419 | vt.inc = NULL; | |
420 | vt.dec = NULL; | |
421 | vt.equal = NULL; | |
422 | ||
423 | dm_array_info_init(&md->era_array_info, md->tm, &vt); | |
424 | } | |
425 | ||
426 | static void setup_infos(struct era_metadata *md) | |
427 | { | |
428 | dm_disk_bitset_init(md->tm, &md->bitset_info); | |
429 | setup_writeset_tree_info(md); | |
430 | setup_era_array_info(md); | |
431 | } | |
432 | ||
433 | /*----------------------------------------------------------------*/ | |
434 | ||
435 | static int create_fresh_metadata(struct era_metadata *md) | |
436 | { | |
437 | int r; | |
438 | ||
439 | r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION, | |
440 | &md->tm, &md->sm); | |
441 | if (r < 0) { | |
442 | DMERR("dm_tm_create_with_sm failed"); | |
443 | return r; | |
444 | } | |
445 | ||
446 | setup_infos(md); | |
447 | ||
448 | r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root); | |
449 | if (r) { | |
450 | DMERR("couldn't create new writeset tree"); | |
451 | goto bad; | |
452 | } | |
453 | ||
454 | r = dm_array_empty(&md->era_array_info, &md->era_array_root); | |
455 | if (r) { | |
456 | DMERR("couldn't create era array"); | |
457 | goto bad; | |
458 | } | |
459 | ||
460 | return 0; | |
461 | ||
462 | bad: | |
463 | dm_sm_destroy(md->sm); | |
464 | dm_tm_destroy(md->tm); | |
465 | ||
466 | return r; | |
467 | } | |
468 | ||
5a32083d JT |
469 | static int save_sm_root(struct era_metadata *md) |
470 | { | |
471 | int r; | |
472 | size_t metadata_len; | |
473 | ||
474 | r = dm_sm_root_size(md->sm, &metadata_len); | |
475 | if (r < 0) | |
476 | return r; | |
477 | ||
478 | return dm_sm_copy_root(md->sm, &md->metadata_space_map_root, | |
479 | metadata_len); | |
480 | } | |
481 | ||
482 | static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) | |
483 | { | |
484 | memcpy(&disk->metadata_space_map_root, | |
485 | &md->metadata_space_map_root, | |
486 | sizeof(md->metadata_space_map_root)); | |
487 | } | |
488 | ||
eec40579 JT |
489 | /* |
490 | * Writes a superblock, including the static fields that don't get updated | |
491 | * with every commit (possible optimisation here). 'md' should be fully | |
492 | * constructed when this is called. | |
493 | */ | |
5a32083d | 494 | static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) |
eec40579 | 495 | { |
eec40579 JT |
496 | disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); |
497 | disk->flags = cpu_to_le32(0ul); | |
498 | ||
499 | /* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ | |
500 | memset(disk->uuid, 0, sizeof(disk->uuid)); | |
501 | disk->version = cpu_to_le32(MAX_ERA_VERSION); | |
502 | ||
5a32083d | 503 | copy_sm_root(md, disk); |
eec40579 JT |
504 | |
505 | disk->data_block_size = cpu_to_le32(md->block_size); | |
506 | disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); | |
507 | disk->nr_blocks = cpu_to_le32(md->nr_blocks); | |
508 | disk->current_era = cpu_to_le32(md->current_era); | |
509 | ||
510 | ws_pack(&md->current_writeset->md, &disk->current_writeset); | |
511 | disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); | |
512 | disk->era_array_root = cpu_to_le64(md->era_array_root); | |
513 | disk->metadata_snap = cpu_to_le64(md->metadata_snap); | |
eec40579 JT |
514 | } |
515 | ||
516 | static int write_superblock(struct era_metadata *md) | |
517 | { | |
518 | int r; | |
519 | struct dm_block *sblock; | |
520 | struct superblock_disk *disk; | |
521 | ||
5a32083d JT |
522 | r = save_sm_root(md); |
523 | if (r) { | |
524 | DMERR("%s: save_sm_root failed", __func__); | |
525 | return r; | |
526 | } | |
527 | ||
eec40579 JT |
528 | r = superblock_lock_zero(md, &sblock); |
529 | if (r) | |
530 | return r; | |
531 | ||
532 | disk = dm_block_data(sblock); | |
5a32083d | 533 | prepare_superblock(md, disk); |
eec40579 JT |
534 | |
535 | return dm_tm_commit(md->tm, sblock); | |
536 | } | |
537 | ||
538 | /* | |
539 | * Assumes block_size and the infos are set. | |
540 | */ | |
541 | static int format_metadata(struct era_metadata *md) | |
542 | { | |
543 | int r; | |
544 | ||
545 | r = create_fresh_metadata(md); | |
546 | if (r) | |
547 | return r; | |
548 | ||
549 | r = write_superblock(md); | |
550 | if (r) { | |
551 | dm_sm_destroy(md->sm); | |
552 | dm_tm_destroy(md->tm); | |
553 | return r; | |
554 | } | |
555 | ||
556 | return 0; | |
557 | } | |
558 | ||
559 | static int open_metadata(struct era_metadata *md) | |
560 | { | |
561 | int r; | |
562 | struct dm_block *sblock; | |
563 | struct superblock_disk *disk; | |
564 | ||
565 | r = superblock_read_lock(md, &sblock); | |
566 | if (r) { | |
567 | DMERR("couldn't read_lock superblock"); | |
568 | return r; | |
569 | } | |
570 | ||
571 | disk = dm_block_data(sblock); | |
c8e846ff NT |
572 | |
573 | /* Verify the data block size hasn't changed */ | |
574 | if (le32_to_cpu(disk->data_block_size) != md->block_size) { | |
575 | DMERR("changing the data block size (from %u to %llu) is not supported", | |
576 | le32_to_cpu(disk->data_block_size), md->block_size); | |
577 | r = -EINVAL; | |
578 | goto bad; | |
579 | } | |
580 | ||
eec40579 JT |
581 | r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, |
582 | disk->metadata_space_map_root, | |
583 | sizeof(disk->metadata_space_map_root), | |
584 | &md->tm, &md->sm); | |
585 | if (r) { | |
586 | DMERR("dm_tm_open_with_sm failed"); | |
587 | goto bad; | |
588 | } | |
589 | ||
590 | setup_infos(md); | |
591 | ||
eec40579 JT |
592 | md->nr_blocks = le32_to_cpu(disk->nr_blocks); |
593 | md->current_era = le32_to_cpu(disk->current_era); | |
594 | ||
de89afc1 | 595 | ws_unpack(&disk->current_writeset, &md->current_writeset->md); |
eec40579 JT |
596 | md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); |
597 | md->era_array_root = le64_to_cpu(disk->era_array_root); | |
598 | md->metadata_snap = le64_to_cpu(disk->metadata_snap); | |
599 | md->archived_writesets = true; | |
600 | ||
4c7da06f MP |
601 | dm_bm_unlock(sblock); |
602 | ||
603 | return 0; | |
eec40579 JT |
604 | |
605 | bad: | |
606 | dm_bm_unlock(sblock); | |
607 | return r; | |
608 | } | |
609 | ||
610 | static int open_or_format_metadata(struct era_metadata *md, | |
611 | bool may_format) | |
612 | { | |
613 | int r; | |
614 | bool unformatted = false; | |
615 | ||
616 | r = superblock_all_zeroes(md->bm, &unformatted); | |
617 | if (r) | |
618 | return r; | |
619 | ||
620 | if (unformatted) | |
621 | return may_format ? format_metadata(md) : -EPERM; | |
622 | ||
623 | return open_metadata(md); | |
624 | } | |
625 | ||
626 | static int create_persistent_data_objects(struct era_metadata *md, | |
627 | bool may_format) | |
628 | { | |
629 | int r; | |
630 | ||
631 | md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE, | |
eec40579 JT |
632 | ERA_MAX_CONCURRENT_LOCKS); |
633 | if (IS_ERR(md->bm)) { | |
634 | DMERR("could not create block manager"); | |
635 | return PTR_ERR(md->bm); | |
636 | } | |
637 | ||
638 | r = open_or_format_metadata(md, may_format); | |
639 | if (r) | |
640 | dm_block_manager_destroy(md->bm); | |
641 | ||
642 | return r; | |
643 | } | |
644 | ||
645 | static void destroy_persistent_data_objects(struct era_metadata *md) | |
646 | { | |
647 | dm_sm_destroy(md->sm); | |
648 | dm_tm_destroy(md->tm); | |
649 | dm_block_manager_destroy(md->bm); | |
650 | } | |
651 | ||
652 | /* | |
653 | * This waits until all era_map threads have picked up the new filter. | |
654 | */ | |
655 | static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) | |
656 | { | |
657 | rcu_assign_pointer(md->current_writeset, new_writeset); | |
658 | synchronize_rcu(); | |
659 | } | |
660 | ||
661 | /*---------------------------------------------------------------- | |
662 | * Writesets get 'digested' into the main era array. | |
663 | * | |
664 | * We're using a coroutine here so the worker thread can do the digestion, | |
665 | * thus avoiding synchronisation of the metadata. Digesting a whole | |
666 | * writeset in one go would cause too much latency. | |
667 | *--------------------------------------------------------------*/ | |
668 | struct digest { | |
669 | uint32_t era; | |
670 | unsigned nr_bits, current_bit; | |
671 | struct writeset_metadata writeset; | |
672 | __le32 value; | |
673 | struct dm_disk_bitset info; | |
674 | ||
675 | int (*step)(struct era_metadata *, struct digest *); | |
676 | }; | |
677 | ||
678 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
679 | struct digest *d); | |
680 | ||
681 | static int metadata_digest_remove_writeset(struct era_metadata *md, | |
682 | struct digest *d) | |
683 | { | |
684 | int r; | |
685 | uint64_t key = d->era; | |
686 | ||
687 | r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root, | |
688 | &key, &md->writeset_tree_root); | |
689 | if (r) { | |
690 | DMERR("%s: dm_btree_remove failed", __func__); | |
691 | return r; | |
692 | } | |
693 | ||
694 | d->step = metadata_digest_lookup_writeset; | |
695 | return 0; | |
696 | } | |
697 | ||
698 | #define INSERTS_PER_STEP 100 | |
699 | ||
700 | static int metadata_digest_transcribe_writeset(struct era_metadata *md, | |
701 | struct digest *d) | |
702 | { | |
703 | int r; | |
704 | bool marked; | |
705 | unsigned b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); | |
706 | ||
707 | for (b = d->current_bit; b < e; b++) { | |
708 | r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked); | |
709 | if (r) { | |
710 | DMERR("%s: writeset_marked_on_disk failed", __func__); | |
711 | return r; | |
712 | } | |
713 | ||
714 | if (!marked) | |
715 | continue; | |
716 | ||
717 | __dm_bless_for_disk(&d->value); | |
718 | r = dm_array_set_value(&md->era_array_info, md->era_array_root, | |
719 | b, &d->value, &md->era_array_root); | |
720 | if (r) { | |
721 | DMERR("%s: dm_array_set_value failed", __func__); | |
722 | return r; | |
723 | } | |
724 | } | |
725 | ||
726 | if (b == d->nr_bits) | |
727 | d->step = metadata_digest_remove_writeset; | |
728 | else | |
729 | d->current_bit = b; | |
730 | ||
731 | return 0; | |
732 | } | |
733 | ||
734 | static int metadata_digest_lookup_writeset(struct era_metadata *md, | |
735 | struct digest *d) | |
736 | { | |
737 | int r; | |
738 | uint64_t key; | |
739 | struct writeset_disk disk; | |
740 | ||
741 | r = dm_btree_find_lowest_key(&md->writeset_tree_info, | |
742 | md->writeset_tree_root, &key); | |
743 | if (r < 0) | |
744 | return r; | |
745 | ||
746 | d->era = key; | |
747 | ||
748 | r = dm_btree_lookup(&md->writeset_tree_info, | |
749 | md->writeset_tree_root, &key, &disk); | |
750 | if (r) { | |
751 | if (r == -ENODATA) { | |
752 | d->step = NULL; | |
753 | return 0; | |
754 | } | |
755 | ||
756 | DMERR("%s: dm_btree_lookup failed", __func__); | |
757 | return r; | |
758 | } | |
759 | ||
760 | ws_unpack(&disk, &d->writeset); | |
761 | d->value = cpu_to_le32(key); | |
762 | ||
25249333 NT |
763 | /* |
764 | * We initialise another bitset info to avoid any caching side effects | |
765 | * with the previous one. | |
766 | */ | |
767 | dm_disk_bitset_init(md->tm, &d->info); | |
768 | ||
eec40579 JT |
769 | d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); |
770 | d->current_bit = 0; | |
771 | d->step = metadata_digest_transcribe_writeset; | |
772 | ||
773 | return 0; | |
774 | } | |
775 | ||
776 | static int metadata_digest_start(struct era_metadata *md, struct digest *d) | |
777 | { | |
778 | if (d->step) | |
779 | return 0; | |
780 | ||
781 | memset(d, 0, sizeof(*d)); | |
eec40579 JT |
782 | d->step = metadata_digest_lookup_writeset; |
783 | ||
784 | return 0; | |
785 | } | |
786 | ||
787 | /*---------------------------------------------------------------- | |
788 | * High level metadata interface. Target methods should use these, and not | |
789 | * the lower level ones. | |
790 | *--------------------------------------------------------------*/ | |
791 | static struct era_metadata *metadata_open(struct block_device *bdev, | |
792 | sector_t block_size, | |
793 | bool may_format) | |
794 | { | |
795 | int r; | |
796 | struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL); | |
797 | ||
798 | if (!md) | |
799 | return NULL; | |
800 | ||
801 | md->bdev = bdev; | |
802 | md->block_size = block_size; | |
803 | ||
804 | md->writesets[0].md.root = INVALID_WRITESET_ROOT; | |
805 | md->writesets[1].md.root = INVALID_WRITESET_ROOT; | |
806 | md->current_writeset = &md->writesets[0]; | |
807 | ||
808 | r = create_persistent_data_objects(md, may_format); | |
809 | if (r) { | |
810 | kfree(md); | |
811 | return ERR_PTR(r); | |
812 | } | |
813 | ||
814 | return md; | |
815 | } | |
816 | ||
817 | static void metadata_close(struct era_metadata *md) | |
818 | { | |
904e6b26 NT |
819 | writeset_free(&md->writesets[0]); |
820 | writeset_free(&md->writesets[1]); | |
eec40579 JT |
821 | destroy_persistent_data_objects(md); |
822 | kfree(md); | |
823 | } | |
824 | ||
825 | static bool valid_nr_blocks(dm_block_t n) | |
826 | { | |
827 | /* | |
828 | * dm_bitset restricts us to 2^32. test_bit & co. restrict us | |
829 | * further to 2^31 - 1 | |
830 | */ | |
831 | return n < (1ull << 31); | |
832 | } | |
833 | ||
834 | static int metadata_resize(struct era_metadata *md, void *arg) | |
835 | { | |
836 | int r; | |
837 | dm_block_t *new_size = arg; | |
838 | __le32 value; | |
839 | ||
840 | if (!valid_nr_blocks(*new_size)) { | |
841 | DMERR("Invalid number of origin blocks %llu", | |
842 | (unsigned long long) *new_size); | |
843 | return -EINVAL; | |
844 | } | |
845 | ||
846 | writeset_free(&md->writesets[0]); | |
847 | writeset_free(&md->writesets[1]); | |
848 | ||
849 | r = writeset_alloc(&md->writesets[0], *new_size); | |
850 | if (r) { | |
851 | DMERR("%s: writeset_alloc failed for writeset 0", __func__); | |
852 | return r; | |
853 | } | |
854 | ||
855 | r = writeset_alloc(&md->writesets[1], *new_size); | |
856 | if (r) { | |
857 | DMERR("%s: writeset_alloc failed for writeset 1", __func__); | |
904e6b26 | 858 | writeset_free(&md->writesets[0]); |
eec40579 JT |
859 | return r; |
860 | } | |
861 | ||
862 | value = cpu_to_le32(0u); | |
863 | __dm_bless_for_disk(&value); | |
864 | r = dm_array_resize(&md->era_array_info, md->era_array_root, | |
865 | md->nr_blocks, *new_size, | |
866 | &value, &md->era_array_root); | |
867 | if (r) { | |
868 | DMERR("%s: dm_array_resize failed", __func__); | |
904e6b26 NT |
869 | writeset_free(&md->writesets[0]); |
870 | writeset_free(&md->writesets[1]); | |
eec40579 JT |
871 | return r; |
872 | } | |
873 | ||
874 | md->nr_blocks = *new_size; | |
875 | return 0; | |
876 | } | |
877 | ||
878 | static int metadata_era_archive(struct era_metadata *md) | |
879 | { | |
880 | int r; | |
881 | uint64_t keys[1]; | |
882 | struct writeset_disk value; | |
883 | ||
884 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, | |
885 | &md->current_writeset->md.root); | |
886 | if (r) { | |
887 | DMERR("%s: dm_bitset_flush failed", __func__); | |
888 | return r; | |
889 | } | |
890 | ||
891 | ws_pack(&md->current_writeset->md, &value); | |
eec40579 JT |
892 | |
893 | keys[0] = md->current_era; | |
894 | __dm_bless_for_disk(&value); | |
895 | r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, | |
896 | keys, &value, &md->writeset_tree_root); | |
897 | if (r) { | |
898 | DMERR("%s: couldn't insert writeset into btree", __func__); | |
899 | /* FIXME: fail mode */ | |
900 | return r; | |
901 | } | |
902 | ||
de89afc1 | 903 | md->current_writeset->md.root = INVALID_WRITESET_ROOT; |
eec40579 JT |
904 | md->archived_writesets = true; |
905 | ||
906 | return 0; | |
907 | } | |
908 | ||
909 | static struct writeset *next_writeset(struct era_metadata *md) | |
910 | { | |
911 | return (md->current_writeset == &md->writesets[0]) ? | |
912 | &md->writesets[1] : &md->writesets[0]; | |
913 | } | |
914 | ||
915 | static int metadata_new_era(struct era_metadata *md) | |
916 | { | |
917 | int r; | |
918 | struct writeset *new_writeset = next_writeset(md); | |
919 | ||
de89afc1 | 920 | r = writeset_init(&md->bitset_info, new_writeset, md->nr_blocks); |
eec40579 JT |
921 | if (r) { |
922 | DMERR("%s: writeset_init failed", __func__); | |
923 | return r; | |
924 | } | |
925 | ||
926 | swap_writeset(md, new_writeset); | |
927 | md->current_era++; | |
928 | ||
929 | return 0; | |
930 | } | |
931 | ||
932 | static int metadata_era_rollover(struct era_metadata *md) | |
933 | { | |
934 | int r; | |
935 | ||
936 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { | |
937 | r = metadata_era_archive(md); | |
938 | if (r) { | |
939 | DMERR("%s: metadata_archive_era failed", __func__); | |
940 | /* FIXME: fail mode? */ | |
941 | return r; | |
942 | } | |
943 | } | |
944 | ||
945 | r = metadata_new_era(md); | |
946 | if (r) { | |
947 | DMERR("%s: new era failed", __func__); | |
948 | /* FIXME: fail mode */ | |
949 | return r; | |
950 | } | |
951 | ||
952 | return 0; | |
953 | } | |
954 | ||
955 | static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) | |
956 | { | |
957 | bool r; | |
958 | struct writeset *ws; | |
959 | ||
960 | rcu_read_lock(); | |
961 | ws = rcu_dereference(md->current_writeset); | |
962 | r = writeset_marked(ws, block); | |
963 | rcu_read_unlock(); | |
964 | ||
965 | return r; | |
966 | } | |
967 | ||
968 | static int metadata_commit(struct era_metadata *md) | |
969 | { | |
970 | int r; | |
971 | struct dm_block *sblock; | |
972 | ||
de89afc1 | 973 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { |
eec40579 JT |
974 | r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, |
975 | &md->current_writeset->md.root); | |
976 | if (r) { | |
977 | DMERR("%s: bitset flush failed", __func__); | |
978 | return r; | |
979 | } | |
980 | } | |
981 | ||
117aceb0 | 982 | r = dm_tm_pre_commit(md->tm); |
5a32083d | 983 | if (r) { |
117aceb0 | 984 | DMERR("%s: pre commit failed", __func__); |
5a32083d JT |
985 | return r; |
986 | } | |
987 | ||
117aceb0 | 988 | r = save_sm_root(md); |
eec40579 | 989 | if (r) { |
117aceb0 | 990 | DMERR("%s: save_sm_root failed", __func__); |
eec40579 JT |
991 | return r; |
992 | } | |
993 | ||
994 | r = superblock_lock(md, &sblock); | |
995 | if (r) { | |
996 | DMERR("%s: superblock lock failed", __func__); | |
997 | return r; | |
998 | } | |
999 | ||
5a32083d | 1000 | prepare_superblock(md, dm_block_data(sblock)); |
eec40579 JT |
1001 | |
1002 | return dm_tm_commit(md->tm, sblock); | |
1003 | } | |
1004 | ||
1005 | static int metadata_checkpoint(struct era_metadata *md) | |
1006 | { | |
1007 | /* | |
1008 | * For now we just rollover, but later I want to put a check in to | |
1009 | * avoid this if the filter is still pretty fresh. | |
1010 | */ | |
1011 | return metadata_era_rollover(md); | |
1012 | } | |
1013 | ||
1014 | /* | |
1015 | * Metadata snapshots allow userland to access era data. | |
1016 | */ | |
1017 | static int metadata_take_snap(struct era_metadata *md) | |
1018 | { | |
1019 | int r, inc; | |
1020 | struct dm_block *clone; | |
1021 | ||
1022 | if (md->metadata_snap != SUPERBLOCK_LOCATION) { | |
1023 | DMERR("%s: metadata snapshot already exists", __func__); | |
1024 | return -EINVAL; | |
1025 | } | |
1026 | ||
1027 | r = metadata_era_rollover(md); | |
1028 | if (r) { | |
1029 | DMERR("%s: era rollover failed", __func__); | |
1030 | return r; | |
1031 | } | |
1032 | ||
1033 | r = metadata_commit(md); | |
1034 | if (r) { | |
1035 | DMERR("%s: pre commit failed", __func__); | |
1036 | return r; | |
1037 | } | |
1038 | ||
1039 | r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); | |
1040 | if (r) { | |
1041 | DMERR("%s: couldn't increment superblock", __func__); | |
1042 | return r; | |
1043 | } | |
1044 | ||
1045 | r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, | |
1046 | &sb_validator, &clone, &inc); | |
1047 | if (r) { | |
1048 | DMERR("%s: couldn't shadow superblock", __func__); | |
1049 | dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); | |
1050 | return r; | |
1051 | } | |
1052 | BUG_ON(!inc); | |
1053 | ||
1054 | r = dm_sm_inc_block(md->sm, md->writeset_tree_root); | |
1055 | if (r) { | |
1056 | DMERR("%s: couldn't inc writeset tree root", __func__); | |
1057 | dm_tm_unlock(md->tm, clone); | |
1058 | return r; | |
1059 | } | |
1060 | ||
1061 | r = dm_sm_inc_block(md->sm, md->era_array_root); | |
1062 | if (r) { | |
1063 | DMERR("%s: couldn't inc era tree root", __func__); | |
1064 | dm_sm_dec_block(md->sm, md->writeset_tree_root); | |
1065 | dm_tm_unlock(md->tm, clone); | |
1066 | return r; | |
1067 | } | |
1068 | ||
1069 | md->metadata_snap = dm_block_location(clone); | |
1070 | ||
4c7da06f | 1071 | dm_tm_unlock(md->tm, clone); |
eec40579 JT |
1072 | |
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | static int metadata_drop_snap(struct era_metadata *md) | |
1077 | { | |
1078 | int r; | |
1079 | dm_block_t location; | |
1080 | struct dm_block *clone; | |
1081 | struct superblock_disk *disk; | |
1082 | ||
1083 | if (md->metadata_snap == SUPERBLOCK_LOCATION) { | |
1084 | DMERR("%s: no snap to drop", __func__); | |
1085 | return -EINVAL; | |
1086 | } | |
1087 | ||
1088 | r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); | |
1089 | if (r) { | |
1090 | DMERR("%s: couldn't read lock superblock clone", __func__); | |
1091 | return r; | |
1092 | } | |
1093 | ||
1094 | /* | |
1095 | * Whatever happens now we'll commit with no record of the metadata | |
1096 | * snap. | |
1097 | */ | |
1098 | md->metadata_snap = SUPERBLOCK_LOCATION; | |
1099 | ||
1100 | disk = dm_block_data(clone); | |
1101 | r = dm_btree_del(&md->writeset_tree_info, | |
1102 | le64_to_cpu(disk->writeset_tree_root)); | |
1103 | if (r) { | |
1104 | DMERR("%s: error deleting writeset tree clone", __func__); | |
1105 | dm_tm_unlock(md->tm, clone); | |
1106 | return r; | |
1107 | } | |
1108 | ||
1109 | r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); | |
1110 | if (r) { | |
1111 | DMERR("%s: error deleting era array clone", __func__); | |
1112 | dm_tm_unlock(md->tm, clone); | |
1113 | return r; | |
1114 | } | |
1115 | ||
1116 | location = dm_block_location(clone); | |
1117 | dm_tm_unlock(md->tm, clone); | |
1118 | ||
1119 | return dm_sm_dec_block(md->sm, location); | |
1120 | } | |
1121 | ||
1122 | struct metadata_stats { | |
1123 | dm_block_t used; | |
1124 | dm_block_t total; | |
1125 | dm_block_t snap; | |
1126 | uint32_t era; | |
1127 | }; | |
1128 | ||
1129 | static int metadata_get_stats(struct era_metadata *md, void *ptr) | |
1130 | { | |
1131 | int r; | |
1132 | struct metadata_stats *s = ptr; | |
1133 | dm_block_t nr_free, nr_total; | |
1134 | ||
1135 | r = dm_sm_get_nr_free(md->sm, &nr_free); | |
1136 | if (r) { | |
1137 | DMERR("dm_sm_get_nr_free returned %d", r); | |
1138 | return r; | |
1139 | } | |
1140 | ||
1141 | r = dm_sm_get_nr_blocks(md->sm, &nr_total); | |
1142 | if (r) { | |
1143 | DMERR("dm_pool_get_metadata_dev_size returned %d", r); | |
1144 | return r; | |
1145 | } | |
1146 | ||
1147 | s->used = nr_total - nr_free; | |
1148 | s->total = nr_total; | |
1149 | s->snap = md->metadata_snap; | |
1150 | s->era = md->current_era; | |
1151 | ||
1152 | return 0; | |
1153 | } | |
1154 | ||
1155 | /*----------------------------------------------------------------*/ | |
1156 | ||
1157 | struct era { | |
1158 | struct dm_target *ti; | |
eec40579 JT |
1159 | |
1160 | struct dm_dev *metadata_dev; | |
1161 | struct dm_dev *origin_dev; | |
1162 | ||
1163 | dm_block_t nr_blocks; | |
1164 | uint32_t sectors_per_block; | |
1165 | int sectors_per_block_shift; | |
1166 | struct era_metadata *md; | |
1167 | ||
1168 | struct workqueue_struct *wq; | |
1169 | struct work_struct worker; | |
1170 | ||
1171 | spinlock_t deferred_lock; | |
1172 | struct bio_list deferred_bios; | |
1173 | ||
1174 | spinlock_t rpc_lock; | |
1175 | struct list_head rpc_calls; | |
1176 | ||
1177 | struct digest digest; | |
1178 | atomic_t suspended; | |
1179 | }; | |
1180 | ||
1181 | struct rpc { | |
1182 | struct list_head list; | |
1183 | ||
1184 | int (*fn0)(struct era_metadata *); | |
1185 | int (*fn1)(struct era_metadata *, void *); | |
1186 | void *arg; | |
1187 | int result; | |
1188 | ||
1189 | struct completion complete; | |
1190 | }; | |
1191 | ||
1192 | /*---------------------------------------------------------------- | |
1193 | * Remapping. | |
1194 | *---------------------------------------------------------------*/ | |
1195 | static bool block_size_is_power_of_two(struct era *era) | |
1196 | { | |
1197 | return era->sectors_per_block_shift >= 0; | |
1198 | } | |
1199 | ||
1200 | static dm_block_t get_block(struct era *era, struct bio *bio) | |
1201 | { | |
1202 | sector_t block_nr = bio->bi_iter.bi_sector; | |
1203 | ||
1204 | if (!block_size_is_power_of_two(era)) | |
1205 | (void) sector_div(block_nr, era->sectors_per_block); | |
1206 | else | |
1207 | block_nr >>= era->sectors_per_block_shift; | |
1208 | ||
1209 | return block_nr; | |
1210 | } | |
1211 | ||
1212 | static void remap_to_origin(struct era *era, struct bio *bio) | |
1213 | { | |
74d46992 | 1214 | bio_set_dev(bio, era->origin_dev->bdev); |
eec40579 JT |
1215 | } |
1216 | ||
1217 | /*---------------------------------------------------------------- | |
1218 | * Worker thread | |
1219 | *--------------------------------------------------------------*/ | |
1220 | static void wake_worker(struct era *era) | |
1221 | { | |
1222 | if (!atomic_read(&era->suspended)) | |
1223 | queue_work(era->wq, &era->worker); | |
1224 | } | |
1225 | ||
1226 | static void process_old_eras(struct era *era) | |
1227 | { | |
1228 | int r; | |
1229 | ||
1230 | if (!era->digest.step) | |
1231 | return; | |
1232 | ||
1233 | r = era->digest.step(era->md, &era->digest); | |
1234 | if (r < 0) { | |
1235 | DMERR("%s: digest step failed, stopping digestion", __func__); | |
1236 | era->digest.step = NULL; | |
1237 | ||
1238 | } else if (era->digest.step) | |
1239 | wake_worker(era); | |
1240 | } | |
1241 | ||
1242 | static void process_deferred_bios(struct era *era) | |
1243 | { | |
1244 | int r; | |
1245 | struct bio_list deferred_bios, marked_bios; | |
1246 | struct bio *bio; | |
2099b145 | 1247 | struct blk_plug plug; |
eec40579 JT |
1248 | bool commit_needed = false; |
1249 | bool failed = false; | |
2099b145 | 1250 | struct writeset *ws = era->md->current_writeset; |
eec40579 JT |
1251 | |
1252 | bio_list_init(&deferred_bios); | |
1253 | bio_list_init(&marked_bios); | |
1254 | ||
1255 | spin_lock(&era->deferred_lock); | |
1256 | bio_list_merge(&deferred_bios, &era->deferred_bios); | |
1257 | bio_list_init(&era->deferred_bios); | |
1258 | spin_unlock(&era->deferred_lock); | |
1259 | ||
2099b145 NT |
1260 | if (bio_list_empty(&deferred_bios)) |
1261 | return; | |
1262 | ||
eec40579 | 1263 | while ((bio = bio_list_pop(&deferred_bios))) { |
2099b145 | 1264 | r = writeset_test_and_set(&era->md->bitset_info, ws, |
eec40579 JT |
1265 | get_block(era, bio)); |
1266 | if (r < 0) { | |
1267 | /* | |
1268 | * This is bad news, we need to rollback. | |
1269 | * FIXME: finish. | |
1270 | */ | |
1271 | failed = true; | |
eec40579 JT |
1272 | } else if (r == 0) |
1273 | commit_needed = true; | |
1274 | ||
1275 | bio_list_add(&marked_bios, bio); | |
1276 | } | |
1277 | ||
1278 | if (commit_needed) { | |
1279 | r = metadata_commit(era->md); | |
1280 | if (r) | |
1281 | failed = true; | |
1282 | } | |
1283 | ||
1284 | if (failed) | |
1285 | while ((bio = bio_list_pop(&marked_bios))) | |
1286 | bio_io_error(bio); | |
2099b145 NT |
1287 | else { |
1288 | blk_start_plug(&plug); | |
1289 | while ((bio = bio_list_pop(&marked_bios))) { | |
1290 | /* | |
1291 | * Only update the in-core writeset if the on-disk one | |
1292 | * was updated too. | |
1293 | */ | |
1294 | if (commit_needed) | |
1295 | set_bit(get_block(era, bio), ws->bits); | |
ed00aabd | 1296 | submit_bio_noacct(bio); |
2099b145 NT |
1297 | } |
1298 | blk_finish_plug(&plug); | |
1299 | } | |
eec40579 JT |
1300 | } |
1301 | ||
1302 | static void process_rpc_calls(struct era *era) | |
1303 | { | |
1304 | int r; | |
1305 | bool need_commit = false; | |
1306 | struct list_head calls; | |
1307 | struct rpc *rpc, *tmp; | |
1308 | ||
1309 | INIT_LIST_HEAD(&calls); | |
1310 | spin_lock(&era->rpc_lock); | |
1311 | list_splice_init(&era->rpc_calls, &calls); | |
1312 | spin_unlock(&era->rpc_lock); | |
1313 | ||
1314 | list_for_each_entry_safe(rpc, tmp, &calls, list) { | |
1315 | rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); | |
1316 | need_commit = true; | |
1317 | } | |
1318 | ||
1319 | if (need_commit) { | |
1320 | r = metadata_commit(era->md); | |
1321 | if (r) | |
1322 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1323 | rpc->result = r; | |
1324 | } | |
1325 | ||
1326 | list_for_each_entry_safe(rpc, tmp, &calls, list) | |
1327 | complete(&rpc->complete); | |
1328 | } | |
1329 | ||
1330 | static void kick_off_digest(struct era *era) | |
1331 | { | |
1332 | if (era->md->archived_writesets) { | |
1333 | era->md->archived_writesets = false; | |
1334 | metadata_digest_start(era->md, &era->digest); | |
1335 | } | |
1336 | } | |
1337 | ||
1338 | static void do_work(struct work_struct *ws) | |
1339 | { | |
1340 | struct era *era = container_of(ws, struct era, worker); | |
1341 | ||
1342 | kick_off_digest(era); | |
1343 | process_old_eras(era); | |
1344 | process_deferred_bios(era); | |
1345 | process_rpc_calls(era); | |
1346 | } | |
1347 | ||
1348 | static void defer_bio(struct era *era, struct bio *bio) | |
1349 | { | |
1350 | spin_lock(&era->deferred_lock); | |
1351 | bio_list_add(&era->deferred_bios, bio); | |
1352 | spin_unlock(&era->deferred_lock); | |
1353 | ||
1354 | wake_worker(era); | |
1355 | } | |
1356 | ||
1357 | /* | |
1358 | * Make an rpc call to the worker to change the metadata. | |
1359 | */ | |
1360 | static int perform_rpc(struct era *era, struct rpc *rpc) | |
1361 | { | |
1362 | rpc->result = 0; | |
1363 | init_completion(&rpc->complete); | |
1364 | ||
1365 | spin_lock(&era->rpc_lock); | |
1366 | list_add(&rpc->list, &era->rpc_calls); | |
1367 | spin_unlock(&era->rpc_lock); | |
1368 | ||
1369 | wake_worker(era); | |
1370 | wait_for_completion(&rpc->complete); | |
1371 | ||
1372 | return rpc->result; | |
1373 | } | |
1374 | ||
1375 | static int in_worker0(struct era *era, int (*fn)(struct era_metadata *)) | |
1376 | { | |
1377 | struct rpc rpc; | |
1378 | rpc.fn0 = fn; | |
1379 | rpc.fn1 = NULL; | |
1380 | ||
1381 | return perform_rpc(era, &rpc); | |
1382 | } | |
1383 | ||
1384 | static int in_worker1(struct era *era, | |
1385 | int (*fn)(struct era_metadata *, void *), void *arg) | |
1386 | { | |
1387 | struct rpc rpc; | |
1388 | rpc.fn0 = NULL; | |
1389 | rpc.fn1 = fn; | |
1390 | rpc.arg = arg; | |
1391 | ||
1392 | return perform_rpc(era, &rpc); | |
1393 | } | |
1394 | ||
1395 | static void start_worker(struct era *era) | |
1396 | { | |
1397 | atomic_set(&era->suspended, 0); | |
1398 | } | |
1399 | ||
1400 | static void stop_worker(struct era *era) | |
1401 | { | |
1402 | atomic_set(&era->suspended, 1); | |
1403 | flush_workqueue(era->wq); | |
1404 | } | |
1405 | ||
1406 | /*---------------------------------------------------------------- | |
1407 | * Target methods | |
1408 | *--------------------------------------------------------------*/ | |
eec40579 JT |
1409 | static void era_destroy(struct era *era) |
1410 | { | |
989f26f5 JT |
1411 | if (era->md) |
1412 | metadata_close(era->md); | |
eec40579 JT |
1413 | |
1414 | if (era->wq) | |
1415 | destroy_workqueue(era->wq); | |
1416 | ||
1417 | if (era->origin_dev) | |
1418 | dm_put_device(era->ti, era->origin_dev); | |
1419 | ||
1420 | if (era->metadata_dev) | |
1421 | dm_put_device(era->ti, era->metadata_dev); | |
1422 | ||
1423 | kfree(era); | |
1424 | } | |
1425 | ||
1426 | static dm_block_t calc_nr_blocks(struct era *era) | |
1427 | { | |
1428 | return dm_sector_div_up(era->ti->len, era->sectors_per_block); | |
1429 | } | |
1430 | ||
1431 | static bool valid_block_size(dm_block_t block_size) | |
1432 | { | |
1433 | bool greater_than_zero = block_size > 0; | |
1434 | bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; | |
1435 | ||
1436 | return greater_than_zero && multiple_of_min_block_size; | |
1437 | } | |
1438 | ||
1439 | /* | |
1440 | * <metadata dev> <data dev> <data block size (sectors)> | |
1441 | */ | |
1442 | static int era_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1443 | { | |
1444 | int r; | |
1445 | char dummy; | |
1446 | struct era *era; | |
1447 | struct era_metadata *md; | |
1448 | ||
1449 | if (argc != 3) { | |
1450 | ti->error = "Invalid argument count"; | |
1451 | return -EINVAL; | |
1452 | } | |
1453 | ||
1454 | era = kzalloc(sizeof(*era), GFP_KERNEL); | |
1455 | if (!era) { | |
1456 | ti->error = "Error allocating era structure"; | |
1457 | return -ENOMEM; | |
1458 | } | |
1459 | ||
1460 | era->ti = ti; | |
1461 | ||
1462 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &era->metadata_dev); | |
1463 | if (r) { | |
1464 | ti->error = "Error opening metadata device"; | |
1465 | era_destroy(era); | |
1466 | return -EINVAL; | |
1467 | } | |
1468 | ||
1469 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &era->origin_dev); | |
1470 | if (r) { | |
1471 | ti->error = "Error opening data device"; | |
1472 | era_destroy(era); | |
1473 | return -EINVAL; | |
1474 | } | |
1475 | ||
1476 | r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); | |
1477 | if (r != 1) { | |
1478 | ti->error = "Error parsing block size"; | |
1479 | era_destroy(era); | |
1480 | return -EINVAL; | |
1481 | } | |
1482 | ||
1483 | r = dm_set_target_max_io_len(ti, era->sectors_per_block); | |
1484 | if (r) { | |
1485 | ti->error = "could not set max io len"; | |
1486 | era_destroy(era); | |
1487 | return -EINVAL; | |
1488 | } | |
1489 | ||
1490 | if (!valid_block_size(era->sectors_per_block)) { | |
1491 | ti->error = "Invalid block size"; | |
1492 | era_destroy(era); | |
1493 | return -EINVAL; | |
1494 | } | |
1495 | if (era->sectors_per_block & (era->sectors_per_block - 1)) | |
1496 | era->sectors_per_block_shift = -1; | |
1497 | else | |
1498 | era->sectors_per_block_shift = __ffs(era->sectors_per_block); | |
1499 | ||
1500 | md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); | |
1501 | if (IS_ERR(md)) { | |
1502 | ti->error = "Error reading metadata"; | |
1503 | era_destroy(era); | |
1504 | return PTR_ERR(md); | |
1505 | } | |
1506 | era->md = md; | |
1507 | ||
eec40579 JT |
1508 | era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); |
1509 | if (!era->wq) { | |
1510 | ti->error = "could not create workqueue for metadata object"; | |
1511 | era_destroy(era); | |
1512 | return -ENOMEM; | |
1513 | } | |
1514 | INIT_WORK(&era->worker, do_work); | |
1515 | ||
1516 | spin_lock_init(&era->deferred_lock); | |
1517 | bio_list_init(&era->deferred_bios); | |
1518 | ||
1519 | spin_lock_init(&era->rpc_lock); | |
1520 | INIT_LIST_HEAD(&era->rpc_calls); | |
1521 | ||
1522 | ti->private = era; | |
1523 | ti->num_flush_bios = 1; | |
1524 | ti->flush_supported = true; | |
1525 | ||
1526 | ti->num_discard_bios = 1; | |
eec40579 JT |
1527 | |
1528 | return 0; | |
1529 | } | |
1530 | ||
1531 | static void era_dtr(struct dm_target *ti) | |
1532 | { | |
1533 | era_destroy(ti->private); | |
1534 | } | |
1535 | ||
1536 | static int era_map(struct dm_target *ti, struct bio *bio) | |
1537 | { | |
1538 | struct era *era = ti->private; | |
1539 | dm_block_t block = get_block(era, bio); | |
1540 | ||
1541 | /* | |
1542 | * All bios get remapped to the origin device. We do this now, but | |
1543 | * it may not get issued until later. Depending on whether the | |
1544 | * block is marked in this era. | |
1545 | */ | |
1546 | remap_to_origin(era, bio); | |
1547 | ||
1548 | /* | |
28a8f0d3 | 1549 | * REQ_PREFLUSH bios carry no data, so we're not interested in them. |
eec40579 | 1550 | */ |
1eff9d32 | 1551 | if (!(bio->bi_opf & REQ_PREFLUSH) && |
eec40579 JT |
1552 | (bio_data_dir(bio) == WRITE) && |
1553 | !metadata_current_marked(era->md, block)) { | |
1554 | defer_bio(era, bio); | |
1555 | return DM_MAPIO_SUBMITTED; | |
1556 | } | |
1557 | ||
1558 | return DM_MAPIO_REMAPPED; | |
1559 | } | |
1560 | ||
1561 | static void era_postsuspend(struct dm_target *ti) | |
1562 | { | |
1563 | int r; | |
1564 | struct era *era = ti->private; | |
1565 | ||
1566 | r = in_worker0(era, metadata_era_archive); | |
1567 | if (r) { | |
1568 | DMERR("%s: couldn't archive current era", __func__); | |
1569 | /* FIXME: fail mode */ | |
1570 | } | |
1571 | ||
1572 | stop_worker(era); | |
1573 | } | |
1574 | ||
1575 | static int era_preresume(struct dm_target *ti) | |
1576 | { | |
1577 | int r; | |
1578 | struct era *era = ti->private; | |
1579 | dm_block_t new_size = calc_nr_blocks(era); | |
1580 | ||
1581 | if (era->nr_blocks != new_size) { | |
cca2c6ae NT |
1582 | r = metadata_resize(era->md, &new_size); |
1583 | if (r) { | |
1584 | DMERR("%s: metadata_resize failed", __func__); | |
eec40579 | 1585 | return r; |
cca2c6ae NT |
1586 | } |
1587 | ||
1588 | r = metadata_commit(era->md); | |
1589 | if (r) { | |
1590 | DMERR("%s: metadata_commit failed", __func__); | |
1591 | return r; | |
1592 | } | |
eec40579 JT |
1593 | |
1594 | era->nr_blocks = new_size; | |
1595 | } | |
1596 | ||
1597 | start_worker(era); | |
1598 | ||
de89afc1 | 1599 | r = in_worker0(era, metadata_era_rollover); |
eec40579 JT |
1600 | if (r) { |
1601 | DMERR("%s: metadata_era_rollover failed", __func__); | |
1602 | return r; | |
1603 | } | |
1604 | ||
1605 | return 0; | |
1606 | } | |
1607 | ||
1608 | /* | |
1609 | * Status format: | |
1610 | * | |
1611 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> | |
1612 | * <current era> <held metadata root | '-'> | |
1613 | */ | |
1614 | static void era_status(struct dm_target *ti, status_type_t type, | |
1615 | unsigned status_flags, char *result, unsigned maxlen) | |
1616 | { | |
1617 | int r; | |
1618 | struct era *era = ti->private; | |
1619 | ssize_t sz = 0; | |
1620 | struct metadata_stats stats; | |
1621 | char buf[BDEVNAME_SIZE]; | |
1622 | ||
1623 | switch (type) { | |
1624 | case STATUSTYPE_INFO: | |
1625 | r = in_worker1(era, metadata_get_stats, &stats); | |
1626 | if (r) | |
1627 | goto err; | |
1628 | ||
1629 | DMEMIT("%u %llu/%llu %u", | |
1630 | (unsigned) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), | |
1631 | (unsigned long long) stats.used, | |
1632 | (unsigned long long) stats.total, | |
1633 | (unsigned) stats.era); | |
1634 | ||
1635 | if (stats.snap != SUPERBLOCK_LOCATION) | |
1636 | DMEMIT(" %llu", stats.snap); | |
1637 | else | |
1638 | DMEMIT(" -"); | |
1639 | break; | |
1640 | ||
1641 | case STATUSTYPE_TABLE: | |
1642 | format_dev_t(buf, era->metadata_dev->bdev->bd_dev); | |
1643 | DMEMIT("%s ", buf); | |
1644 | format_dev_t(buf, era->origin_dev->bdev->bd_dev); | |
1645 | DMEMIT("%s %u", buf, era->sectors_per_block); | |
1646 | break; | |
1647 | } | |
1648 | ||
1649 | return; | |
1650 | ||
1651 | err: | |
1652 | DMEMIT("Error"); | |
1653 | } | |
1654 | ||
1eb5fa84 MS |
1655 | static int era_message(struct dm_target *ti, unsigned argc, char **argv, |
1656 | char *result, unsigned maxlen) | |
eec40579 JT |
1657 | { |
1658 | struct era *era = ti->private; | |
1659 | ||
1660 | if (argc != 1) { | |
1661 | DMERR("incorrect number of message arguments"); | |
1662 | return -EINVAL; | |
1663 | } | |
1664 | ||
1665 | if (!strcasecmp(argv[0], "checkpoint")) | |
1666 | return in_worker0(era, metadata_checkpoint); | |
1667 | ||
1668 | if (!strcasecmp(argv[0], "take_metadata_snap")) | |
1669 | return in_worker0(era, metadata_take_snap); | |
1670 | ||
1671 | if (!strcasecmp(argv[0], "drop_metadata_snap")) | |
1672 | return in_worker0(era, metadata_drop_snap); | |
1673 | ||
1674 | DMERR("unsupported message '%s'", argv[0]); | |
1675 | return -EINVAL; | |
1676 | } | |
1677 | ||
1678 | static sector_t get_dev_size(struct dm_dev *dev) | |
1679 | { | |
1680 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
1681 | } | |
1682 | ||
1683 | static int era_iterate_devices(struct dm_target *ti, | |
1684 | iterate_devices_callout_fn fn, void *data) | |
1685 | { | |
1686 | struct era *era = ti->private; | |
1687 | return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); | |
1688 | } | |
1689 | ||
eec40579 JT |
1690 | static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) |
1691 | { | |
1692 | struct era *era = ti->private; | |
1693 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; | |
1694 | ||
1695 | /* | |
1696 | * If the system-determined stacked limits are compatible with the | |
1697 | * era device's blocksize (io_opt is a factor) do not override them. | |
1698 | */ | |
1699 | if (io_opt_sectors < era->sectors_per_block || | |
1700 | do_div(io_opt_sectors, era->sectors_per_block)) { | |
1701 | blk_limits_io_min(limits, 0); | |
1702 | blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT); | |
1703 | } | |
1704 | } | |
1705 | ||
1706 | /*----------------------------------------------------------------*/ | |
1707 | ||
1708 | static struct target_type era_target = { | |
1709 | .name = "era", | |
1710 | .version = {1, 0, 0}, | |
1711 | .module = THIS_MODULE, | |
1712 | .ctr = era_ctr, | |
1713 | .dtr = era_dtr, | |
1714 | .map = era_map, | |
1715 | .postsuspend = era_postsuspend, | |
1716 | .preresume = era_preresume, | |
1717 | .status = era_status, | |
1718 | .message = era_message, | |
1719 | .iterate_devices = era_iterate_devices, | |
eec40579 JT |
1720 | .io_hints = era_io_hints |
1721 | }; | |
1722 | ||
1723 | static int __init dm_era_init(void) | |
1724 | { | |
1725 | int r; | |
1726 | ||
1727 | r = dm_register_target(&era_target); | |
1728 | if (r) { | |
1729 | DMERR("era target registration failed: %d", r); | |
1730 | return r; | |
1731 | } | |
1732 | ||
1733 | return 0; | |
1734 | } | |
1735 | ||
1736 | static void __exit dm_era_exit(void) | |
1737 | { | |
1738 | dm_unregister_target(&era_target); | |
1739 | } | |
1740 | ||
1741 | module_init(dm_era_init); | |
1742 | module_exit(dm_era_exit); | |
1743 | ||
1744 | MODULE_DESCRIPTION(DM_NAME " era target"); | |
1745 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
1746 | MODULE_LICENSE("GPL"); |