1 | // SPDX-License-Identifier: GPL-2.0-only |
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 | *-------------------------------------------------------------- |
27 | * Writeset |
28 | *-------------------------------------------------------------- |
29 | */ |
30 | struct writeset_metadata { |
31 | uint32_t nr_bits; |
32 | dm_block_t root; |
33 | }; |
34 | |
35 | struct writeset { |
36 | struct writeset_metadata md; |
37 | |
38 | /* |
39 | * An in core copy of the bits to save constantly doing look ups on |
40 | * disk. |
41 | */ |
42 | unsigned long *bits; |
43 | }; |
44 | |
45 | /* |
46 | * This does not free off the on disk bitset as this will normally be done |
47 | * after digesting into the era array. |
48 | */ |
49 | static void writeset_free(struct writeset *ws) |
50 | { |
51 | vfree(addr: ws->bits); |
52 | ws->bits = NULL; |
53 | } |
54 | |
55 | static int setup_on_disk_bitset(struct dm_disk_bitset *info, |
56 | unsigned int nr_bits, dm_block_t *root) |
57 | { |
58 | int r; |
59 | |
60 | r = dm_bitset_empty(info, new_root: root); |
61 | if (r) |
62 | return r; |
63 | |
64 | return dm_bitset_resize(info, old_root: *root, old_nr_entries: 0, new_nr_entries: nr_bits, default_value: false, new_root: root); |
65 | } |
66 | |
67 | static size_t bitset_size(unsigned int nr_bits) |
68 | { |
69 | return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); |
70 | } |
71 | |
72 | /* |
73 | * Allocates memory for the in core bitset. |
74 | */ |
75 | static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) |
76 | { |
77 | ws->bits = vzalloc(size: bitset_size(nr_bits: nr_blocks)); |
78 | if (!ws->bits) { |
79 | DMERR("%s: couldn't allocate in memory bitset" , __func__); |
80 | return -ENOMEM; |
81 | } |
82 | |
83 | return 0; |
84 | } |
85 | |
86 | /* |
87 | * Wipes the in-core bitset, and creates a new on disk bitset. |
88 | */ |
89 | static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws, |
90 | dm_block_t nr_blocks) |
91 | { |
92 | int r; |
93 | |
94 | memset(ws->bits, 0, bitset_size(nr_blocks)); |
95 | |
96 | ws->md.nr_bits = nr_blocks; |
97 | r = setup_on_disk_bitset(info, nr_bits: ws->md.nr_bits, root: &ws->md.root); |
98 | if (r) { |
99 | DMERR("%s: setup_on_disk_bitset failed" , __func__); |
100 | return r; |
101 | } |
102 | |
103 | return 0; |
104 | } |
105 | |
106 | static bool writeset_marked(struct writeset *ws, dm_block_t block) |
107 | { |
108 | return test_bit(block, ws->bits); |
109 | } |
110 | |
111 | static int writeset_marked_on_disk(struct dm_disk_bitset *info, |
112 | struct writeset_metadata *m, dm_block_t block, |
113 | bool *result) |
114 | { |
115 | int r; |
116 | dm_block_t old = m->root; |
117 | |
118 | /* |
119 | * The bitset was flushed when it was archived, so we know there'll |
120 | * be no change to the root. |
121 | */ |
122 | r = dm_bitset_test_bit(info, root: m->root, index: block, new_root: &m->root, result); |
123 | if (r) { |
124 | DMERR("%s: dm_bitset_test_bit failed" , __func__); |
125 | return r; |
126 | } |
127 | |
128 | BUG_ON(m->root != old); |
129 | |
130 | return r; |
131 | } |
132 | |
133 | /* |
134 | * Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. |
135 | */ |
136 | static int writeset_test_and_set(struct dm_disk_bitset *info, |
137 | struct writeset *ws, uint32_t block) |
138 | { |
139 | int r; |
140 | |
141 | if (!test_bit(block, ws->bits)) { |
142 | r = dm_bitset_set_bit(info, root: ws->md.root, index: block, new_root: &ws->md.root); |
143 | if (r) { |
144 | /* FIXME: fail mode */ |
145 | return r; |
146 | } |
147 | |
148 | return 0; |
149 | } |
150 | |
151 | return 1; |
152 | } |
153 | |
154 | /* |
155 | *-------------------------------------------------------------- |
156 | * On disk metadata layout |
157 | *-------------------------------------------------------------- |
158 | */ |
159 | #define SPACE_MAP_ROOT_SIZE 128 |
160 | #define UUID_LEN 16 |
161 | |
162 | struct writeset_disk { |
163 | __le32 nr_bits; |
164 | __le64 root; |
165 | } __packed; |
166 | |
167 | struct superblock_disk { |
168 | __le32 csum; |
169 | __le32 flags; |
170 | __le64 blocknr; |
171 | |
172 | __u8 uuid[UUID_LEN]; |
173 | __le64 magic; |
174 | __le32 version; |
175 | |
176 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
177 | |
178 | __le32 data_block_size; |
179 | __le32 metadata_block_size; |
180 | __le32 nr_blocks; |
181 | |
182 | __le32 current_era; |
183 | struct writeset_disk current_writeset; |
184 | |
185 | /* |
186 | * Only these two fields are valid within the metadata snapshot. |
187 | */ |
188 | __le64 writeset_tree_root; |
189 | __le64 era_array_root; |
190 | |
191 | __le64 metadata_snap; |
192 | } __packed; |
193 | |
194 | /* |
195 | *-------------------------------------------------------------- |
196 | * Superblock validation |
197 | *-------------------------------------------------------------- |
198 | */ |
199 | static void sb_prepare_for_write(struct dm_block_validator *v, |
200 | struct dm_block *b, |
201 | size_t sb_block_size) |
202 | { |
203 | struct superblock_disk *disk = dm_block_data(b); |
204 | |
205 | disk->blocknr = cpu_to_le64(dm_block_location(b)); |
206 | disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, |
207 | sb_block_size - sizeof(__le32), |
208 | SUPERBLOCK_CSUM_XOR)); |
209 | } |
210 | |
211 | static int check_metadata_version(struct superblock_disk *disk) |
212 | { |
213 | uint32_t metadata_version = le32_to_cpu(disk->version); |
214 | |
215 | if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { |
216 | DMERR("Era metadata version %u found, but only versions between %u and %u supported." , |
217 | metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); |
218 | return -EINVAL; |
219 | } |
220 | |
221 | return 0; |
222 | } |
223 | |
224 | static int sb_check(struct dm_block_validator *v, |
225 | struct dm_block *b, |
226 | size_t sb_block_size) |
227 | { |
228 | struct superblock_disk *disk = dm_block_data(b); |
229 | __le32 csum_le; |
230 | |
231 | if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { |
232 | DMERR("%s failed: blocknr %llu: wanted %llu" , |
233 | __func__, le64_to_cpu(disk->blocknr), |
234 | (unsigned long long)dm_block_location(b)); |
235 | return -ENOTBLK; |
236 | } |
237 | |
238 | if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { |
239 | DMERR("%s failed: magic %llu: wanted %llu" , |
240 | __func__, le64_to_cpu(disk->magic), |
241 | (unsigned long long) SUPERBLOCK_MAGIC); |
242 | return -EILSEQ; |
243 | } |
244 | |
245 | csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, |
246 | sb_block_size - sizeof(__le32), |
247 | SUPERBLOCK_CSUM_XOR)); |
248 | if (csum_le != disk->csum) { |
249 | DMERR("%s failed: csum %u: wanted %u" , |
250 | __func__, le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); |
251 | return -EILSEQ; |
252 | } |
253 | |
254 | return check_metadata_version(disk); |
255 | } |
256 | |
257 | static struct dm_block_validator sb_validator = { |
258 | .name = "superblock" , |
259 | .prepare_for_write = sb_prepare_for_write, |
260 | .check = sb_check |
261 | }; |
262 | |
263 | /* |
264 | *-------------------------------------------------------------- |
265 | * Low level metadata handling |
266 | *-------------------------------------------------------------- |
267 | */ |
268 | #define DM_ERA_METADATA_BLOCK_SIZE 4096 |
269 | #define ERA_MAX_CONCURRENT_LOCKS 5 |
270 | |
271 | struct era_metadata { |
272 | struct block_device *bdev; |
273 | struct dm_block_manager *bm; |
274 | struct dm_space_map *sm; |
275 | struct dm_transaction_manager *tm; |
276 | |
277 | dm_block_t block_size; |
278 | uint32_t nr_blocks; |
279 | |
280 | uint32_t current_era; |
281 | |
282 | /* |
283 | * We preallocate 2 writesets. When an era rolls over we |
284 | * switch between them. This means the allocation is done at |
285 | * preresume time, rather than on the io path. |
286 | */ |
287 | struct writeset writesets[2]; |
288 | struct writeset *current_writeset; |
289 | |
290 | dm_block_t writeset_tree_root; |
291 | dm_block_t era_array_root; |
292 | |
293 | struct dm_disk_bitset bitset_info; |
294 | struct dm_btree_info writeset_tree_info; |
295 | struct dm_array_info era_array_info; |
296 | |
297 | dm_block_t metadata_snap; |
298 | |
299 | /* |
300 | * A flag that is set whenever a writeset has been archived. |
301 | */ |
302 | bool archived_writesets; |
303 | |
304 | /* |
305 | * Reading the space map root can fail, so we read it into this |
306 | * buffer before the superblock is locked and updated. |
307 | */ |
308 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
309 | }; |
310 | |
311 | static int superblock_read_lock(struct era_metadata *md, |
312 | struct dm_block **sblock) |
313 | { |
314 | return dm_bm_read_lock(bm: md->bm, SUPERBLOCK_LOCATION, |
315 | v: &sb_validator, result: sblock); |
316 | } |
317 | |
318 | static int superblock_lock_zero(struct era_metadata *md, |
319 | struct dm_block **sblock) |
320 | { |
321 | return dm_bm_write_lock_zero(bm: md->bm, SUPERBLOCK_LOCATION, |
322 | v: &sb_validator, result: sblock); |
323 | } |
324 | |
325 | static int superblock_lock(struct era_metadata *md, |
326 | struct dm_block **sblock) |
327 | { |
328 | return dm_bm_write_lock(bm: md->bm, SUPERBLOCK_LOCATION, |
329 | v: &sb_validator, result: sblock); |
330 | } |
331 | |
332 | /* FIXME: duplication with cache and thin */ |
333 | static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result) |
334 | { |
335 | int r; |
336 | unsigned int i; |
337 | struct dm_block *b; |
338 | __le64 *data_le, zero = cpu_to_le64(0); |
339 | unsigned int sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); |
340 | |
341 | /* |
342 | * We can't use a validator here - it may be all zeroes. |
343 | */ |
344 | r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, result: &b); |
345 | if (r) |
346 | return r; |
347 | |
348 | data_le = dm_block_data(b); |
349 | *result = true; |
350 | for (i = 0; i < sb_block_size; i++) { |
351 | if (data_le[i] != zero) { |
352 | *result = false; |
353 | break; |
354 | } |
355 | } |
356 | |
357 | dm_bm_unlock(b); |
358 | |
359 | return 0; |
360 | } |
361 | |
362 | /*----------------------------------------------------------------*/ |
363 | |
364 | static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) |
365 | { |
366 | disk->nr_bits = cpu_to_le32(core->nr_bits); |
367 | disk->root = cpu_to_le64(core->root); |
368 | } |
369 | |
370 | static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) |
371 | { |
372 | core->nr_bits = le32_to_cpu(disk->nr_bits); |
373 | core->root = le64_to_cpu(disk->root); |
374 | } |
375 | |
376 | static void ws_inc(void *context, const void *value, unsigned int count) |
377 | { |
378 | struct era_metadata *md = context; |
379 | struct writeset_disk ws_d; |
380 | dm_block_t b; |
381 | unsigned int i; |
382 | |
383 | for (i = 0; i < count; i++) { |
384 | memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); |
385 | b = le64_to_cpu(ws_d.root); |
386 | dm_tm_inc(tm: md->tm, b); |
387 | } |
388 | } |
389 | |
390 | static void ws_dec(void *context, const void *value, unsigned int count) |
391 | { |
392 | struct era_metadata *md = context; |
393 | struct writeset_disk ws_d; |
394 | dm_block_t b; |
395 | unsigned int i; |
396 | |
397 | for (i = 0; i < count; i++) { |
398 | memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); |
399 | b = le64_to_cpu(ws_d.root); |
400 | dm_bitset_del(info: &md->bitset_info, root: b); |
401 | } |
402 | } |
403 | |
404 | static int ws_eq(void *context, const void *value1, const void *value2) |
405 | { |
406 | return !memcmp(p: value1, q: value2, size: sizeof(struct writeset_disk)); |
407 | } |
408 | |
409 | /*----------------------------------------------------------------*/ |
410 | |
411 | static void setup_writeset_tree_info(struct era_metadata *md) |
412 | { |
413 | struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; |
414 | |
415 | md->writeset_tree_info.tm = md->tm; |
416 | md->writeset_tree_info.levels = 1; |
417 | vt->context = md; |
418 | vt->size = sizeof(struct writeset_disk); |
419 | vt->inc = ws_inc; |
420 | vt->dec = ws_dec; |
421 | vt->equal = ws_eq; |
422 | } |
423 | |
424 | static void setup_era_array_info(struct era_metadata *md) |
425 | { |
426 | struct dm_btree_value_type vt; |
427 | |
428 | vt.context = NULL; |
429 | vt.size = sizeof(__le32); |
430 | vt.inc = NULL; |
431 | vt.dec = NULL; |
432 | vt.equal = NULL; |
433 | |
434 | dm_array_info_init(info: &md->era_array_info, tm: md->tm, vt: &vt); |
435 | } |
436 | |
437 | static void setup_infos(struct era_metadata *md) |
438 | { |
439 | dm_disk_bitset_init(tm: md->tm, info: &md->bitset_info); |
440 | setup_writeset_tree_info(md); |
441 | setup_era_array_info(md); |
442 | } |
443 | |
444 | /*----------------------------------------------------------------*/ |
445 | |
446 | static int create_fresh_metadata(struct era_metadata *md) |
447 | { |
448 | int r; |
449 | |
450 | r = dm_tm_create_with_sm(bm: md->bm, SUPERBLOCK_LOCATION, |
451 | tm: &md->tm, sm: &md->sm); |
452 | if (r < 0) { |
453 | DMERR("dm_tm_create_with_sm failed" ); |
454 | return r; |
455 | } |
456 | |
457 | setup_infos(md); |
458 | |
459 | r = dm_btree_empty(info: &md->writeset_tree_info, root: &md->writeset_tree_root); |
460 | if (r) { |
461 | DMERR("couldn't create new writeset tree" ); |
462 | goto bad; |
463 | } |
464 | |
465 | r = dm_array_empty(info: &md->era_array_info, root: &md->era_array_root); |
466 | if (r) { |
467 | DMERR("couldn't create era array" ); |
468 | goto bad; |
469 | } |
470 | |
471 | return 0; |
472 | |
473 | bad: |
474 | dm_sm_destroy(sm: md->sm); |
475 | dm_tm_destroy(tm: md->tm); |
476 | |
477 | return r; |
478 | } |
479 | |
480 | static int save_sm_root(struct era_metadata *md) |
481 | { |
482 | int r; |
483 | size_t metadata_len; |
484 | |
485 | r = dm_sm_root_size(sm: md->sm, result: &metadata_len); |
486 | if (r < 0) |
487 | return r; |
488 | |
489 | return dm_sm_copy_root(sm: md->sm, copy_to_here_le: &md->metadata_space_map_root, |
490 | len: metadata_len); |
491 | } |
492 | |
493 | static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) |
494 | { |
495 | memcpy(&disk->metadata_space_map_root, |
496 | &md->metadata_space_map_root, |
497 | sizeof(md->metadata_space_map_root)); |
498 | } |
499 | |
500 | /* |
501 | * Writes a superblock, including the static fields that don't get updated |
502 | * with every commit (possible optimisation here). 'md' should be fully |
503 | * constructed when this is called. |
504 | */ |
505 | static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) |
506 | { |
507 | disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); |
508 | disk->flags = cpu_to_le32(0ul); |
509 | |
510 | /* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ |
511 | memset(disk->uuid, 0, sizeof(disk->uuid)); |
512 | disk->version = cpu_to_le32(MAX_ERA_VERSION); |
513 | |
514 | copy_sm_root(md, disk); |
515 | |
516 | disk->data_block_size = cpu_to_le32(md->block_size); |
517 | disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); |
518 | disk->nr_blocks = cpu_to_le32(md->nr_blocks); |
519 | disk->current_era = cpu_to_le32(md->current_era); |
520 | |
521 | ws_pack(core: &md->current_writeset->md, disk: &disk->current_writeset); |
522 | disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); |
523 | disk->era_array_root = cpu_to_le64(md->era_array_root); |
524 | disk->metadata_snap = cpu_to_le64(md->metadata_snap); |
525 | } |
526 | |
527 | static int write_superblock(struct era_metadata *md) |
528 | { |
529 | int r; |
530 | struct dm_block *sblock; |
531 | struct superblock_disk *disk; |
532 | |
533 | r = save_sm_root(md); |
534 | if (r) { |
535 | DMERR("%s: save_sm_root failed" , __func__); |
536 | return r; |
537 | } |
538 | |
539 | r = superblock_lock_zero(md, sblock: &sblock); |
540 | if (r) |
541 | return r; |
542 | |
543 | disk = dm_block_data(b: sblock); |
544 | prepare_superblock(md, disk); |
545 | |
546 | return dm_tm_commit(tm: md->tm, superblock: sblock); |
547 | } |
548 | |
549 | /* |
550 | * Assumes block_size and the infos are set. |
551 | */ |
552 | static int format_metadata(struct era_metadata *md) |
553 | { |
554 | int r; |
555 | |
556 | r = create_fresh_metadata(md); |
557 | if (r) |
558 | return r; |
559 | |
560 | r = write_superblock(md); |
561 | if (r) { |
562 | dm_sm_destroy(sm: md->sm); |
563 | dm_tm_destroy(tm: md->tm); |
564 | return r; |
565 | } |
566 | |
567 | return 0; |
568 | } |
569 | |
570 | static int open_metadata(struct era_metadata *md) |
571 | { |
572 | int r; |
573 | struct dm_block *sblock; |
574 | struct superblock_disk *disk; |
575 | |
576 | r = superblock_read_lock(md, sblock: &sblock); |
577 | if (r) { |
578 | DMERR("couldn't read_lock superblock" ); |
579 | return r; |
580 | } |
581 | |
582 | disk = dm_block_data(b: sblock); |
583 | |
584 | /* Verify the data block size hasn't changed */ |
585 | if (le32_to_cpu(disk->data_block_size) != md->block_size) { |
586 | DMERR("changing the data block size (from %u to %llu) is not supported" , |
587 | le32_to_cpu(disk->data_block_size), md->block_size); |
588 | r = -EINVAL; |
589 | goto bad; |
590 | } |
591 | |
592 | r = dm_tm_open_with_sm(bm: md->bm, SUPERBLOCK_LOCATION, |
593 | sm_root: disk->metadata_space_map_root, |
594 | root_len: sizeof(disk->metadata_space_map_root), |
595 | tm: &md->tm, sm: &md->sm); |
596 | if (r) { |
597 | DMERR("dm_tm_open_with_sm failed" ); |
598 | goto bad; |
599 | } |
600 | |
601 | setup_infos(md); |
602 | |
603 | md->nr_blocks = le32_to_cpu(disk->nr_blocks); |
604 | md->current_era = le32_to_cpu(disk->current_era); |
605 | |
606 | ws_unpack(disk: &disk->current_writeset, core: &md->current_writeset->md); |
607 | md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); |
608 | md->era_array_root = le64_to_cpu(disk->era_array_root); |
609 | md->metadata_snap = le64_to_cpu(disk->metadata_snap); |
610 | md->archived_writesets = true; |
611 | |
612 | dm_bm_unlock(b: sblock); |
613 | |
614 | return 0; |
615 | |
616 | bad: |
617 | dm_bm_unlock(b: sblock); |
618 | return r; |
619 | } |
620 | |
621 | static int open_or_format_metadata(struct era_metadata *md, |
622 | bool may_format) |
623 | { |
624 | int r; |
625 | bool unformatted = false; |
626 | |
627 | r = superblock_all_zeroes(bm: md->bm, result: &unformatted); |
628 | if (r) |
629 | return r; |
630 | |
631 | if (unformatted) |
632 | return may_format ? format_metadata(md) : -EPERM; |
633 | |
634 | return open_metadata(md); |
635 | } |
636 | |
637 | static int create_persistent_data_objects(struct era_metadata *md, |
638 | bool may_format) |
639 | { |
640 | int r; |
641 | |
642 | md->bm = dm_block_manager_create(bdev: md->bdev, DM_ERA_METADATA_BLOCK_SIZE, |
643 | ERA_MAX_CONCURRENT_LOCKS); |
644 | if (IS_ERR(ptr: md->bm)) { |
645 | DMERR("could not create block manager" ); |
646 | return PTR_ERR(ptr: md->bm); |
647 | } |
648 | |
649 | r = open_or_format_metadata(md, may_format); |
650 | if (r) |
651 | dm_block_manager_destroy(bm: md->bm); |
652 | |
653 | return r; |
654 | } |
655 | |
656 | static void destroy_persistent_data_objects(struct era_metadata *md) |
657 | { |
658 | dm_sm_destroy(sm: md->sm); |
659 | dm_tm_destroy(tm: md->tm); |
660 | dm_block_manager_destroy(bm: md->bm); |
661 | } |
662 | |
663 | /* |
664 | * This waits until all era_map threads have picked up the new filter. |
665 | */ |
666 | static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) |
667 | { |
668 | rcu_assign_pointer(md->current_writeset, new_writeset); |
669 | synchronize_rcu(); |
670 | } |
671 | |
672 | /* |
673 | *------------------------------------------------------------------------ |
674 | * Writesets get 'digested' into the main era array. |
675 | * |
676 | * We're using a coroutine here so the worker thread can do the digestion, |
677 | * thus avoiding synchronisation of the metadata. Digesting a whole |
678 | * writeset in one go would cause too much latency. |
679 | *------------------------------------------------------------------------ |
680 | */ |
681 | struct digest { |
682 | uint32_t era; |
683 | unsigned int nr_bits, current_bit; |
684 | struct writeset_metadata writeset; |
685 | __le32 value; |
686 | struct dm_disk_bitset info; |
687 | |
688 | int (*step)(struct era_metadata *md, struct digest *d); |
689 | }; |
690 | |
691 | static int metadata_digest_lookup_writeset(struct era_metadata *md, |
692 | struct digest *d); |
693 | |
694 | static int metadata_digest_remove_writeset(struct era_metadata *md, |
695 | struct digest *d) |
696 | { |
697 | int r; |
698 | uint64_t key = d->era; |
699 | |
700 | r = dm_btree_remove(info: &md->writeset_tree_info, root: md->writeset_tree_root, |
701 | keys: &key, new_root: &md->writeset_tree_root); |
702 | if (r) { |
703 | DMERR("%s: dm_btree_remove failed" , __func__); |
704 | return r; |
705 | } |
706 | |
707 | d->step = metadata_digest_lookup_writeset; |
708 | return 0; |
709 | } |
710 | |
711 | #define INSERTS_PER_STEP 100 |
712 | |
713 | static int metadata_digest_transcribe_writeset(struct era_metadata *md, |
714 | struct digest *d) |
715 | { |
716 | int r; |
717 | bool marked; |
718 | unsigned int b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); |
719 | |
720 | for (b = d->current_bit; b < e; b++) { |
721 | r = writeset_marked_on_disk(info: &d->info, m: &d->writeset, block: b, result: &marked); |
722 | if (r) { |
723 | DMERR("%s: writeset_marked_on_disk failed" , __func__); |
724 | return r; |
725 | } |
726 | |
727 | if (!marked) |
728 | continue; |
729 | |
730 | __dm_bless_for_disk(&d->value); |
731 | r = dm_array_set_value(info: &md->era_array_info, root: md->era_array_root, |
732 | index: b, value: &d->value, new_root: &md->era_array_root); |
733 | if (r) { |
734 | DMERR("%s: dm_array_set_value failed" , __func__); |
735 | return r; |
736 | } |
737 | } |
738 | |
739 | if (b == d->nr_bits) |
740 | d->step = metadata_digest_remove_writeset; |
741 | else |
742 | d->current_bit = b; |
743 | |
744 | return 0; |
745 | } |
746 | |
747 | static int metadata_digest_lookup_writeset(struct era_metadata *md, |
748 | struct digest *d) |
749 | { |
750 | int r; |
751 | uint64_t key; |
752 | struct writeset_disk disk; |
753 | |
754 | r = dm_btree_find_lowest_key(info: &md->writeset_tree_info, |
755 | root: md->writeset_tree_root, result_keys: &key); |
756 | if (r < 0) |
757 | return r; |
758 | |
759 | d->era = key; |
760 | |
761 | r = dm_btree_lookup(info: &md->writeset_tree_info, |
762 | root: md->writeset_tree_root, keys: &key, value_le: &disk); |
763 | if (r) { |
764 | if (r == -ENODATA) { |
765 | d->step = NULL; |
766 | return 0; |
767 | } |
768 | |
769 | DMERR("%s: dm_btree_lookup failed" , __func__); |
770 | return r; |
771 | } |
772 | |
773 | ws_unpack(disk: &disk, core: &d->writeset); |
774 | d->value = cpu_to_le32(key); |
775 | |
776 | /* |
777 | * We initialise another bitset info to avoid any caching side effects |
778 | * with the previous one. |
779 | */ |
780 | dm_disk_bitset_init(tm: md->tm, info: &d->info); |
781 | |
782 | d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); |
783 | d->current_bit = 0; |
784 | d->step = metadata_digest_transcribe_writeset; |
785 | |
786 | return 0; |
787 | } |
788 | |
789 | static int metadata_digest_start(struct era_metadata *md, struct digest *d) |
790 | { |
791 | if (d->step) |
792 | return 0; |
793 | |
794 | memset(d, 0, sizeof(*d)); |
795 | d->step = metadata_digest_lookup_writeset; |
796 | |
797 | return 0; |
798 | } |
799 | |
800 | /* |
801 | *----------------------------------------------------------------- |
802 | * High level metadata interface. Target methods should use these, |
803 | * and not the lower level ones. |
804 | *----------------------------------------------------------------- |
805 | */ |
806 | static struct era_metadata *metadata_open(struct block_device *bdev, |
807 | sector_t block_size, |
808 | bool may_format) |
809 | { |
810 | int r; |
811 | struct era_metadata *md = kzalloc(size: sizeof(*md), GFP_KERNEL); |
812 | |
813 | if (!md) |
814 | return NULL; |
815 | |
816 | md->bdev = bdev; |
817 | md->block_size = block_size; |
818 | |
819 | md->writesets[0].md.root = INVALID_WRITESET_ROOT; |
820 | md->writesets[1].md.root = INVALID_WRITESET_ROOT; |
821 | md->current_writeset = &md->writesets[0]; |
822 | |
823 | r = create_persistent_data_objects(md, may_format); |
824 | if (r) { |
825 | kfree(objp: md); |
826 | return ERR_PTR(error: r); |
827 | } |
828 | |
829 | return md; |
830 | } |
831 | |
832 | static void metadata_close(struct era_metadata *md) |
833 | { |
834 | writeset_free(ws: &md->writesets[0]); |
835 | writeset_free(ws: &md->writesets[1]); |
836 | destroy_persistent_data_objects(md); |
837 | kfree(objp: md); |
838 | } |
839 | |
840 | static bool valid_nr_blocks(dm_block_t n) |
841 | { |
842 | /* |
843 | * dm_bitset restricts us to 2^32. test_bit & co. restrict us |
844 | * further to 2^31 - 1 |
845 | */ |
846 | return n < (1ull << 31); |
847 | } |
848 | |
849 | static int metadata_resize(struct era_metadata *md, void *arg) |
850 | { |
851 | int r; |
852 | dm_block_t *new_size = arg; |
853 | __le32 value; |
854 | |
855 | if (!valid_nr_blocks(n: *new_size)) { |
856 | DMERR("Invalid number of origin blocks %llu" , |
857 | (unsigned long long) *new_size); |
858 | return -EINVAL; |
859 | } |
860 | |
861 | writeset_free(ws: &md->writesets[0]); |
862 | writeset_free(ws: &md->writesets[1]); |
863 | |
864 | r = writeset_alloc(ws: &md->writesets[0], nr_blocks: *new_size); |
865 | if (r) { |
866 | DMERR("%s: writeset_alloc failed for writeset 0" , __func__); |
867 | return r; |
868 | } |
869 | |
870 | r = writeset_alloc(ws: &md->writesets[1], nr_blocks: *new_size); |
871 | if (r) { |
872 | DMERR("%s: writeset_alloc failed for writeset 1" , __func__); |
873 | writeset_free(ws: &md->writesets[0]); |
874 | return r; |
875 | } |
876 | |
877 | value = cpu_to_le32(0u); |
878 | __dm_bless_for_disk(&value); |
879 | r = dm_array_resize(info: &md->era_array_info, root: md->era_array_root, |
880 | old_size: md->nr_blocks, new_size: *new_size, |
881 | value: &value, new_root: &md->era_array_root); |
882 | if (r) { |
883 | DMERR("%s: dm_array_resize failed" , __func__); |
884 | writeset_free(ws: &md->writesets[0]); |
885 | writeset_free(ws: &md->writesets[1]); |
886 | return r; |
887 | } |
888 | |
889 | md->nr_blocks = *new_size; |
890 | return 0; |
891 | } |
892 | |
893 | static int metadata_era_archive(struct era_metadata *md) |
894 | { |
895 | int r; |
896 | uint64_t keys[1]; |
897 | struct writeset_disk value; |
898 | |
899 | r = dm_bitset_flush(info: &md->bitset_info, root: md->current_writeset->md.root, |
900 | new_root: &md->current_writeset->md.root); |
901 | if (r) { |
902 | DMERR("%s: dm_bitset_flush failed" , __func__); |
903 | return r; |
904 | } |
905 | |
906 | ws_pack(core: &md->current_writeset->md, disk: &value); |
907 | |
908 | keys[0] = md->current_era; |
909 | __dm_bless_for_disk(&value); |
910 | r = dm_btree_insert(info: &md->writeset_tree_info, root: md->writeset_tree_root, |
911 | keys, value: &value, new_root: &md->writeset_tree_root); |
912 | if (r) { |
913 | DMERR("%s: couldn't insert writeset into btree" , __func__); |
914 | /* FIXME: fail mode */ |
915 | return r; |
916 | } |
917 | |
918 | md->current_writeset->md.root = INVALID_WRITESET_ROOT; |
919 | md->archived_writesets = true; |
920 | |
921 | return 0; |
922 | } |
923 | |
924 | static struct writeset *next_writeset(struct era_metadata *md) |
925 | { |
926 | return (md->current_writeset == &md->writesets[0]) ? |
927 | &md->writesets[1] : &md->writesets[0]; |
928 | } |
929 | |
930 | static int metadata_new_era(struct era_metadata *md) |
931 | { |
932 | int r; |
933 | struct writeset *new_writeset = next_writeset(md); |
934 | |
935 | r = writeset_init(info: &md->bitset_info, ws: new_writeset, nr_blocks: md->nr_blocks); |
936 | if (r) { |
937 | DMERR("%s: writeset_init failed" , __func__); |
938 | return r; |
939 | } |
940 | |
941 | swap_writeset(md, new_writeset); |
942 | md->current_era++; |
943 | |
944 | return 0; |
945 | } |
946 | |
947 | static int metadata_era_rollover(struct era_metadata *md) |
948 | { |
949 | int r; |
950 | |
951 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { |
952 | r = metadata_era_archive(md); |
953 | if (r) { |
954 | DMERR("%s: metadata_archive_era failed" , __func__); |
955 | /* FIXME: fail mode? */ |
956 | return r; |
957 | } |
958 | } |
959 | |
960 | r = metadata_new_era(md); |
961 | if (r) { |
962 | DMERR("%s: new era failed" , __func__); |
963 | /* FIXME: fail mode */ |
964 | return r; |
965 | } |
966 | |
967 | return 0; |
968 | } |
969 | |
970 | static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) |
971 | { |
972 | bool r; |
973 | struct writeset *ws; |
974 | |
975 | rcu_read_lock(); |
976 | ws = rcu_dereference(md->current_writeset); |
977 | r = writeset_marked(ws, block); |
978 | rcu_read_unlock(); |
979 | |
980 | return r; |
981 | } |
982 | |
983 | static int metadata_commit(struct era_metadata *md) |
984 | { |
985 | int r; |
986 | struct dm_block *sblock; |
987 | |
988 | if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { |
989 | r = dm_bitset_flush(info: &md->bitset_info, root: md->current_writeset->md.root, |
990 | new_root: &md->current_writeset->md.root); |
991 | if (r) { |
992 | DMERR("%s: bitset flush failed" , __func__); |
993 | return r; |
994 | } |
995 | } |
996 | |
997 | r = dm_tm_pre_commit(tm: md->tm); |
998 | if (r) { |
999 | DMERR("%s: pre commit failed" , __func__); |
1000 | return r; |
1001 | } |
1002 | |
1003 | r = save_sm_root(md); |
1004 | if (r) { |
1005 | DMERR("%s: save_sm_root failed" , __func__); |
1006 | return r; |
1007 | } |
1008 | |
1009 | r = superblock_lock(md, sblock: &sblock); |
1010 | if (r) { |
1011 | DMERR("%s: superblock lock failed" , __func__); |
1012 | return r; |
1013 | } |
1014 | |
1015 | prepare_superblock(md, disk: dm_block_data(b: sblock)); |
1016 | |
1017 | return dm_tm_commit(tm: md->tm, superblock: sblock); |
1018 | } |
1019 | |
1020 | static int metadata_checkpoint(struct era_metadata *md) |
1021 | { |
1022 | /* |
1023 | * For now we just rollover, but later I want to put a check in to |
1024 | * avoid this if the filter is still pretty fresh. |
1025 | */ |
1026 | return metadata_era_rollover(md); |
1027 | } |
1028 | |
1029 | /* |
1030 | * Metadata snapshots allow userland to access era data. |
1031 | */ |
1032 | static int metadata_take_snap(struct era_metadata *md) |
1033 | { |
1034 | int r, inc; |
1035 | struct dm_block *clone; |
1036 | |
1037 | if (md->metadata_snap != SUPERBLOCK_LOCATION) { |
1038 | DMERR("%s: metadata snapshot already exists" , __func__); |
1039 | return -EINVAL; |
1040 | } |
1041 | |
1042 | r = metadata_era_rollover(md); |
1043 | if (r) { |
1044 | DMERR("%s: era rollover failed" , __func__); |
1045 | return r; |
1046 | } |
1047 | |
1048 | r = metadata_commit(md); |
1049 | if (r) { |
1050 | DMERR("%s: pre commit failed" , __func__); |
1051 | return r; |
1052 | } |
1053 | |
1054 | r = dm_sm_inc_block(sm: md->sm, SUPERBLOCK_LOCATION); |
1055 | if (r) { |
1056 | DMERR("%s: couldn't increment superblock" , __func__); |
1057 | return r; |
1058 | } |
1059 | |
1060 | r = dm_tm_shadow_block(tm: md->tm, SUPERBLOCK_LOCATION, |
1061 | v: &sb_validator, result: &clone, inc_children: &inc); |
1062 | if (r) { |
1063 | DMERR("%s: couldn't shadow superblock" , __func__); |
1064 | dm_sm_dec_block(sm: md->sm, SUPERBLOCK_LOCATION); |
1065 | return r; |
1066 | } |
1067 | BUG_ON(!inc); |
1068 | |
1069 | r = dm_sm_inc_block(sm: md->sm, b: md->writeset_tree_root); |
1070 | if (r) { |
1071 | DMERR("%s: couldn't inc writeset tree root" , __func__); |
1072 | dm_tm_unlock(tm: md->tm, b: clone); |
1073 | return r; |
1074 | } |
1075 | |
1076 | r = dm_sm_inc_block(sm: md->sm, b: md->era_array_root); |
1077 | if (r) { |
1078 | DMERR("%s: couldn't inc era tree root" , __func__); |
1079 | dm_sm_dec_block(sm: md->sm, b: md->writeset_tree_root); |
1080 | dm_tm_unlock(tm: md->tm, b: clone); |
1081 | return r; |
1082 | } |
1083 | |
1084 | md->metadata_snap = dm_block_location(b: clone); |
1085 | |
1086 | dm_tm_unlock(tm: md->tm, b: clone); |
1087 | |
1088 | return 0; |
1089 | } |
1090 | |
1091 | static int metadata_drop_snap(struct era_metadata *md) |
1092 | { |
1093 | int r; |
1094 | dm_block_t location; |
1095 | struct dm_block *clone; |
1096 | struct superblock_disk *disk; |
1097 | |
1098 | if (md->metadata_snap == SUPERBLOCK_LOCATION) { |
1099 | DMERR("%s: no snap to drop" , __func__); |
1100 | return -EINVAL; |
1101 | } |
1102 | |
1103 | r = dm_tm_read_lock(tm: md->tm, b: md->metadata_snap, v: &sb_validator, result: &clone); |
1104 | if (r) { |
1105 | DMERR("%s: couldn't read lock superblock clone" , __func__); |
1106 | return r; |
1107 | } |
1108 | |
1109 | /* |
1110 | * Whatever happens now we'll commit with no record of the metadata |
1111 | * snap. |
1112 | */ |
1113 | md->metadata_snap = SUPERBLOCK_LOCATION; |
1114 | |
1115 | disk = dm_block_data(b: clone); |
1116 | r = dm_btree_del(info: &md->writeset_tree_info, |
1117 | le64_to_cpu(disk->writeset_tree_root)); |
1118 | if (r) { |
1119 | DMERR("%s: error deleting writeset tree clone" , __func__); |
1120 | dm_tm_unlock(tm: md->tm, b: clone); |
1121 | return r; |
1122 | } |
1123 | |
1124 | r = dm_array_del(info: &md->era_array_info, le64_to_cpu(disk->era_array_root)); |
1125 | if (r) { |
1126 | DMERR("%s: error deleting era array clone" , __func__); |
1127 | dm_tm_unlock(tm: md->tm, b: clone); |
1128 | return r; |
1129 | } |
1130 | |
1131 | location = dm_block_location(b: clone); |
1132 | dm_tm_unlock(tm: md->tm, b: clone); |
1133 | |
1134 | return dm_sm_dec_block(sm: md->sm, b: location); |
1135 | } |
1136 | |
1137 | struct metadata_stats { |
1138 | dm_block_t used; |
1139 | dm_block_t total; |
1140 | dm_block_t snap; |
1141 | uint32_t era; |
1142 | }; |
1143 | |
1144 | static int metadata_get_stats(struct era_metadata *md, void *ptr) |
1145 | { |
1146 | int r; |
1147 | struct metadata_stats *s = ptr; |
1148 | dm_block_t nr_free, nr_total; |
1149 | |
1150 | r = dm_sm_get_nr_free(sm: md->sm, count: &nr_free); |
1151 | if (r) { |
1152 | DMERR("dm_sm_get_nr_free returned %d" , r); |
1153 | return r; |
1154 | } |
1155 | |
1156 | r = dm_sm_get_nr_blocks(sm: md->sm, count: &nr_total); |
1157 | if (r) { |
1158 | DMERR("dm_pool_get_metadata_dev_size returned %d" , r); |
1159 | return r; |
1160 | } |
1161 | |
1162 | s->used = nr_total - nr_free; |
1163 | s->total = nr_total; |
1164 | s->snap = md->metadata_snap; |
1165 | s->era = md->current_era; |
1166 | |
1167 | return 0; |
1168 | } |
1169 | |
1170 | /*----------------------------------------------------------------*/ |
1171 | |
1172 | struct era { |
1173 | struct dm_target *ti; |
1174 | |
1175 | struct dm_dev *metadata_dev; |
1176 | struct dm_dev *origin_dev; |
1177 | |
1178 | dm_block_t nr_blocks; |
1179 | uint32_t sectors_per_block; |
1180 | int sectors_per_block_shift; |
1181 | struct era_metadata *md; |
1182 | |
1183 | struct workqueue_struct *wq; |
1184 | struct work_struct worker; |
1185 | |
1186 | spinlock_t deferred_lock; |
1187 | struct bio_list deferred_bios; |
1188 | |
1189 | spinlock_t rpc_lock; |
1190 | struct list_head rpc_calls; |
1191 | |
1192 | struct digest digest; |
1193 | atomic_t suspended; |
1194 | }; |
1195 | |
1196 | struct rpc { |
1197 | struct list_head list; |
1198 | |
1199 | int (*fn0)(struct era_metadata *md); |
1200 | int (*fn1)(struct era_metadata *md, void *ref); |
1201 | void *arg; |
1202 | int result; |
1203 | |
1204 | struct completion complete; |
1205 | }; |
1206 | |
1207 | /* |
1208 | *--------------------------------------------------------------- |
1209 | * Remapping. |
1210 | *--------------------------------------------------------------- |
1211 | */ |
1212 | static bool block_size_is_power_of_two(struct era *era) |
1213 | { |
1214 | return era->sectors_per_block_shift >= 0; |
1215 | } |
1216 | |
1217 | static dm_block_t get_block(struct era *era, struct bio *bio) |
1218 | { |
1219 | sector_t block_nr = bio->bi_iter.bi_sector; |
1220 | |
1221 | if (!block_size_is_power_of_two(era)) |
1222 | (void) sector_div(block_nr, era->sectors_per_block); |
1223 | else |
1224 | block_nr >>= era->sectors_per_block_shift; |
1225 | |
1226 | return block_nr; |
1227 | } |
1228 | |
1229 | static void remap_to_origin(struct era *era, struct bio *bio) |
1230 | { |
1231 | bio_set_dev(bio, bdev: era->origin_dev->bdev); |
1232 | } |
1233 | |
1234 | /* |
1235 | *-------------------------------------------------------------- |
1236 | * Worker thread |
1237 | *-------------------------------------------------------------- |
1238 | */ |
1239 | static void wake_worker(struct era *era) |
1240 | { |
1241 | if (!atomic_read(v: &era->suspended)) |
1242 | queue_work(wq: era->wq, work: &era->worker); |
1243 | } |
1244 | |
1245 | static void process_old_eras(struct era *era) |
1246 | { |
1247 | int r; |
1248 | |
1249 | if (!era->digest.step) |
1250 | return; |
1251 | |
1252 | r = era->digest.step(era->md, &era->digest); |
1253 | if (r < 0) { |
1254 | DMERR("%s: digest step failed, stopping digestion" , __func__); |
1255 | era->digest.step = NULL; |
1256 | |
1257 | } else if (era->digest.step) |
1258 | wake_worker(era); |
1259 | } |
1260 | |
1261 | static void process_deferred_bios(struct era *era) |
1262 | { |
1263 | int r; |
1264 | struct bio_list deferred_bios, marked_bios; |
1265 | struct bio *bio; |
1266 | struct blk_plug plug; |
1267 | bool commit_needed = false; |
1268 | bool failed = false; |
1269 | struct writeset *ws = era->md->current_writeset; |
1270 | |
1271 | bio_list_init(bl: &deferred_bios); |
1272 | bio_list_init(bl: &marked_bios); |
1273 | |
1274 | spin_lock(lock: &era->deferred_lock); |
1275 | bio_list_merge(bl: &deferred_bios, bl2: &era->deferred_bios); |
1276 | bio_list_init(bl: &era->deferred_bios); |
1277 | spin_unlock(lock: &era->deferred_lock); |
1278 | |
1279 | if (bio_list_empty(bl: &deferred_bios)) |
1280 | return; |
1281 | |
1282 | while ((bio = bio_list_pop(bl: &deferred_bios))) { |
1283 | r = writeset_test_and_set(info: &era->md->bitset_info, ws, |
1284 | block: get_block(era, bio)); |
1285 | if (r < 0) { |
1286 | /* |
1287 | * This is bad news, we need to rollback. |
1288 | * FIXME: finish. |
1289 | */ |
1290 | failed = true; |
1291 | } else if (r == 0) |
1292 | commit_needed = true; |
1293 | |
1294 | bio_list_add(bl: &marked_bios, bio); |
1295 | } |
1296 | |
1297 | if (commit_needed) { |
1298 | r = metadata_commit(md: era->md); |
1299 | if (r) |
1300 | failed = true; |
1301 | } |
1302 | |
1303 | if (failed) |
1304 | while ((bio = bio_list_pop(bl: &marked_bios))) |
1305 | bio_io_error(bio); |
1306 | else { |
1307 | blk_start_plug(&plug); |
1308 | while ((bio = bio_list_pop(bl: &marked_bios))) { |
1309 | /* |
1310 | * Only update the in-core writeset if the on-disk one |
1311 | * was updated too. |
1312 | */ |
1313 | if (commit_needed) |
1314 | set_bit(nr: get_block(era, bio), addr: ws->bits); |
1315 | submit_bio_noacct(bio); |
1316 | } |
1317 | blk_finish_plug(&plug); |
1318 | } |
1319 | } |
1320 | |
1321 | static void process_rpc_calls(struct era *era) |
1322 | { |
1323 | int r; |
1324 | bool need_commit = false; |
1325 | struct list_head calls; |
1326 | struct rpc *rpc, *tmp; |
1327 | |
1328 | INIT_LIST_HEAD(list: &calls); |
1329 | spin_lock(lock: &era->rpc_lock); |
1330 | list_splice_init(list: &era->rpc_calls, head: &calls); |
1331 | spin_unlock(lock: &era->rpc_lock); |
1332 | |
1333 | list_for_each_entry_safe(rpc, tmp, &calls, list) { |
1334 | rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); |
1335 | need_commit = true; |
1336 | } |
1337 | |
1338 | if (need_commit) { |
1339 | r = metadata_commit(md: era->md); |
1340 | if (r) |
1341 | list_for_each_entry_safe(rpc, tmp, &calls, list) |
1342 | rpc->result = r; |
1343 | } |
1344 | |
1345 | list_for_each_entry_safe(rpc, tmp, &calls, list) |
1346 | complete(&rpc->complete); |
1347 | } |
1348 | |
1349 | static void kick_off_digest(struct era *era) |
1350 | { |
1351 | if (era->md->archived_writesets) { |
1352 | era->md->archived_writesets = false; |
1353 | metadata_digest_start(md: era->md, d: &era->digest); |
1354 | } |
1355 | } |
1356 | |
1357 | static void do_work(struct work_struct *ws) |
1358 | { |
1359 | struct era *era = container_of(ws, struct era, worker); |
1360 | |
1361 | kick_off_digest(era); |
1362 | process_old_eras(era); |
1363 | process_deferred_bios(era); |
1364 | process_rpc_calls(era); |
1365 | } |
1366 | |
1367 | static void defer_bio(struct era *era, struct bio *bio) |
1368 | { |
1369 | spin_lock(lock: &era->deferred_lock); |
1370 | bio_list_add(bl: &era->deferred_bios, bio); |
1371 | spin_unlock(lock: &era->deferred_lock); |
1372 | |
1373 | wake_worker(era); |
1374 | } |
1375 | |
1376 | /* |
1377 | * Make an rpc call to the worker to change the metadata. |
1378 | */ |
1379 | static int perform_rpc(struct era *era, struct rpc *rpc) |
1380 | { |
1381 | rpc->result = 0; |
1382 | init_completion(x: &rpc->complete); |
1383 | |
1384 | spin_lock(lock: &era->rpc_lock); |
1385 | list_add(new: &rpc->list, head: &era->rpc_calls); |
1386 | spin_unlock(lock: &era->rpc_lock); |
1387 | |
1388 | wake_worker(era); |
1389 | wait_for_completion(&rpc->complete); |
1390 | |
1391 | return rpc->result; |
1392 | } |
1393 | |
1394 | static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md)) |
1395 | { |
1396 | struct rpc rpc; |
1397 | |
1398 | rpc.fn0 = fn; |
1399 | rpc.fn1 = NULL; |
1400 | |
1401 | return perform_rpc(era, rpc: &rpc); |
1402 | } |
1403 | |
1404 | static int in_worker1(struct era *era, |
1405 | int (*fn)(struct era_metadata *md, void *ref), void *arg) |
1406 | { |
1407 | struct rpc rpc; |
1408 | |
1409 | rpc.fn0 = NULL; |
1410 | rpc.fn1 = fn; |
1411 | rpc.arg = arg; |
1412 | |
1413 | return perform_rpc(era, rpc: &rpc); |
1414 | } |
1415 | |
1416 | static void start_worker(struct era *era) |
1417 | { |
1418 | atomic_set(v: &era->suspended, i: 0); |
1419 | } |
1420 | |
1421 | static void stop_worker(struct era *era) |
1422 | { |
1423 | atomic_set(v: &era->suspended, i: 1); |
1424 | drain_workqueue(wq: era->wq); |
1425 | } |
1426 | |
1427 | /* |
1428 | *-------------------------------------------------------------- |
1429 | * Target methods |
1430 | *-------------------------------------------------------------- |
1431 | */ |
1432 | static void era_destroy(struct era *era) |
1433 | { |
1434 | if (era->md) |
1435 | metadata_close(md: era->md); |
1436 | |
1437 | if (era->wq) |
1438 | destroy_workqueue(wq: era->wq); |
1439 | |
1440 | if (era->origin_dev) |
1441 | dm_put_device(ti: era->ti, d: era->origin_dev); |
1442 | |
1443 | if (era->metadata_dev) |
1444 | dm_put_device(ti: era->ti, d: era->metadata_dev); |
1445 | |
1446 | kfree(objp: era); |
1447 | } |
1448 | |
1449 | static dm_block_t calc_nr_blocks(struct era *era) |
1450 | { |
1451 | return dm_sector_div_up(era->ti->len, era->sectors_per_block); |
1452 | } |
1453 | |
1454 | static bool valid_block_size(dm_block_t block_size) |
1455 | { |
1456 | bool greater_than_zero = block_size > 0; |
1457 | bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; |
1458 | |
1459 | return greater_than_zero && multiple_of_min_block_size; |
1460 | } |
1461 | |
1462 | /* |
1463 | * <metadata dev> <data dev> <data block size (sectors)> |
1464 | */ |
1465 | static int era_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
1466 | { |
1467 | int r; |
1468 | char dummy; |
1469 | struct era *era; |
1470 | struct era_metadata *md; |
1471 | |
1472 | if (argc != 3) { |
1473 | ti->error = "Invalid argument count" ; |
1474 | return -EINVAL; |
1475 | } |
1476 | |
1477 | era = kzalloc(size: sizeof(*era), GFP_KERNEL); |
1478 | if (!era) { |
1479 | ti->error = "Error allocating era structure" ; |
1480 | return -ENOMEM; |
1481 | } |
1482 | |
1483 | era->ti = ti; |
1484 | |
1485 | r = dm_get_device(ti, path: argv[0], BLK_OPEN_READ | BLK_OPEN_WRITE, |
1486 | result: &era->metadata_dev); |
1487 | if (r) { |
1488 | ti->error = "Error opening metadata device" ; |
1489 | era_destroy(era); |
1490 | return -EINVAL; |
1491 | } |
1492 | |
1493 | r = dm_get_device(ti, path: argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE, |
1494 | result: &era->origin_dev); |
1495 | if (r) { |
1496 | ti->error = "Error opening data device" ; |
1497 | era_destroy(era); |
1498 | return -EINVAL; |
1499 | } |
1500 | |
1501 | r = sscanf(argv[2], "%u%c" , &era->sectors_per_block, &dummy); |
1502 | if (r != 1) { |
1503 | ti->error = "Error parsing block size" ; |
1504 | era_destroy(era); |
1505 | return -EINVAL; |
1506 | } |
1507 | |
1508 | r = dm_set_target_max_io_len(ti, len: era->sectors_per_block); |
1509 | if (r) { |
1510 | ti->error = "could not set max io len" ; |
1511 | era_destroy(era); |
1512 | return -EINVAL; |
1513 | } |
1514 | |
1515 | if (!valid_block_size(block_size: era->sectors_per_block)) { |
1516 | ti->error = "Invalid block size" ; |
1517 | era_destroy(era); |
1518 | return -EINVAL; |
1519 | } |
1520 | if (era->sectors_per_block & (era->sectors_per_block - 1)) |
1521 | era->sectors_per_block_shift = -1; |
1522 | else |
1523 | era->sectors_per_block_shift = __ffs(era->sectors_per_block); |
1524 | |
1525 | md = metadata_open(bdev: era->metadata_dev->bdev, block_size: era->sectors_per_block, may_format: true); |
1526 | if (IS_ERR(ptr: md)) { |
1527 | ti->error = "Error reading metadata" ; |
1528 | era_destroy(era); |
1529 | return PTR_ERR(ptr: md); |
1530 | } |
1531 | era->md = md; |
1532 | |
1533 | era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); |
1534 | if (!era->wq) { |
1535 | ti->error = "could not create workqueue for metadata object" ; |
1536 | era_destroy(era); |
1537 | return -ENOMEM; |
1538 | } |
1539 | INIT_WORK(&era->worker, do_work); |
1540 | |
1541 | spin_lock_init(&era->deferred_lock); |
1542 | bio_list_init(bl: &era->deferred_bios); |
1543 | |
1544 | spin_lock_init(&era->rpc_lock); |
1545 | INIT_LIST_HEAD(list: &era->rpc_calls); |
1546 | |
1547 | ti->private = era; |
1548 | ti->num_flush_bios = 1; |
1549 | ti->flush_supported = true; |
1550 | |
1551 | ti->num_discard_bios = 1; |
1552 | |
1553 | return 0; |
1554 | } |
1555 | |
1556 | static void era_dtr(struct dm_target *ti) |
1557 | { |
1558 | era_destroy(era: ti->private); |
1559 | } |
1560 | |
1561 | static int era_map(struct dm_target *ti, struct bio *bio) |
1562 | { |
1563 | struct era *era = ti->private; |
1564 | dm_block_t block = get_block(era, bio); |
1565 | |
1566 | /* |
1567 | * All bios get remapped to the origin device. We do this now, but |
1568 | * it may not get issued until later. Depending on whether the |
1569 | * block is marked in this era. |
1570 | */ |
1571 | remap_to_origin(era, bio); |
1572 | |
1573 | /* |
1574 | * REQ_PREFLUSH bios carry no data, so we're not interested in them. |
1575 | */ |
1576 | if (!(bio->bi_opf & REQ_PREFLUSH) && |
1577 | (bio_data_dir(bio) == WRITE) && |
1578 | !metadata_current_marked(md: era->md, block)) { |
1579 | defer_bio(era, bio); |
1580 | return DM_MAPIO_SUBMITTED; |
1581 | } |
1582 | |
1583 | return DM_MAPIO_REMAPPED; |
1584 | } |
1585 | |
1586 | static void era_postsuspend(struct dm_target *ti) |
1587 | { |
1588 | int r; |
1589 | struct era *era = ti->private; |
1590 | |
1591 | r = in_worker0(era, fn: metadata_era_archive); |
1592 | if (r) { |
1593 | DMERR("%s: couldn't archive current era" , __func__); |
1594 | /* FIXME: fail mode */ |
1595 | } |
1596 | |
1597 | stop_worker(era); |
1598 | |
1599 | r = metadata_commit(md: era->md); |
1600 | if (r) { |
1601 | DMERR("%s: metadata_commit failed" , __func__); |
1602 | /* FIXME: fail mode */ |
1603 | } |
1604 | } |
1605 | |
1606 | static int era_preresume(struct dm_target *ti) |
1607 | { |
1608 | int r; |
1609 | struct era *era = ti->private; |
1610 | dm_block_t new_size = calc_nr_blocks(era); |
1611 | |
1612 | if (era->nr_blocks != new_size) { |
1613 | r = metadata_resize(md: era->md, arg: &new_size); |
1614 | if (r) { |
1615 | DMERR("%s: metadata_resize failed" , __func__); |
1616 | return r; |
1617 | } |
1618 | |
1619 | r = metadata_commit(md: era->md); |
1620 | if (r) { |
1621 | DMERR("%s: metadata_commit failed" , __func__); |
1622 | return r; |
1623 | } |
1624 | |
1625 | era->nr_blocks = new_size; |
1626 | } |
1627 | |
1628 | start_worker(era); |
1629 | |
1630 | r = in_worker0(era, fn: metadata_era_rollover); |
1631 | if (r) { |
1632 | DMERR("%s: metadata_era_rollover failed" , __func__); |
1633 | return r; |
1634 | } |
1635 | |
1636 | return 0; |
1637 | } |
1638 | |
1639 | /* |
1640 | * Status format: |
1641 | * |
1642 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
1643 | * <current era> <held metadata root | '-'> |
1644 | */ |
1645 | static void era_status(struct dm_target *ti, status_type_t type, |
1646 | unsigned int status_flags, char *result, unsigned int maxlen) |
1647 | { |
1648 | int r; |
1649 | struct era *era = ti->private; |
1650 | ssize_t sz = 0; |
1651 | struct metadata_stats stats; |
1652 | char buf[BDEVNAME_SIZE]; |
1653 | |
1654 | switch (type) { |
1655 | case STATUSTYPE_INFO: |
1656 | r = in_worker1(era, fn: metadata_get_stats, arg: &stats); |
1657 | if (r) |
1658 | goto err; |
1659 | |
1660 | DMEMIT("%u %llu/%llu %u" , |
1661 | (unsigned int) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), |
1662 | (unsigned long long) stats.used, |
1663 | (unsigned long long) stats.total, |
1664 | (unsigned int) stats.era); |
1665 | |
1666 | if (stats.snap != SUPERBLOCK_LOCATION) |
1667 | DMEMIT(" %llu" , stats.snap); |
1668 | else |
1669 | DMEMIT(" -" ); |
1670 | break; |
1671 | |
1672 | case STATUSTYPE_TABLE: |
1673 | format_dev_t(buf, era->metadata_dev->bdev->bd_dev); |
1674 | DMEMIT("%s " , buf); |
1675 | format_dev_t(buf, era->origin_dev->bdev->bd_dev); |
1676 | DMEMIT("%s %u" , buf, era->sectors_per_block); |
1677 | break; |
1678 | |
1679 | case STATUSTYPE_IMA: |
1680 | *result = '\0'; |
1681 | break; |
1682 | } |
1683 | |
1684 | return; |
1685 | |
1686 | err: |
1687 | DMEMIT("Error" ); |
1688 | } |
1689 | |
1690 | static int era_message(struct dm_target *ti, unsigned int argc, char **argv, |
1691 | char *result, unsigned int maxlen) |
1692 | { |
1693 | struct era *era = ti->private; |
1694 | |
1695 | if (argc != 1) { |
1696 | DMERR("incorrect number of message arguments" ); |
1697 | return -EINVAL; |
1698 | } |
1699 | |
1700 | if (!strcasecmp(s1: argv[0], s2: "checkpoint" )) |
1701 | return in_worker0(era, fn: metadata_checkpoint); |
1702 | |
1703 | if (!strcasecmp(s1: argv[0], s2: "take_metadata_snap" )) |
1704 | return in_worker0(era, fn: metadata_take_snap); |
1705 | |
1706 | if (!strcasecmp(s1: argv[0], s2: "drop_metadata_snap" )) |
1707 | return in_worker0(era, fn: metadata_drop_snap); |
1708 | |
1709 | DMERR("unsupported message '%s'" , argv[0]); |
1710 | return -EINVAL; |
1711 | } |
1712 | |
1713 | static sector_t get_dev_size(struct dm_dev *dev) |
1714 | { |
1715 | return bdev_nr_sectors(bdev: dev->bdev); |
1716 | } |
1717 | |
1718 | static int era_iterate_devices(struct dm_target *ti, |
1719 | iterate_devices_callout_fn fn, void *data) |
1720 | { |
1721 | struct era *era = ti->private; |
1722 | |
1723 | return fn(ti, era->origin_dev, 0, get_dev_size(dev: era->origin_dev), data); |
1724 | } |
1725 | |
1726 | static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) |
1727 | { |
1728 | struct era *era = ti->private; |
1729 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
1730 | |
1731 | /* |
1732 | * If the system-determined stacked limits are compatible with the |
1733 | * era device's blocksize (io_opt is a factor) do not override them. |
1734 | */ |
1735 | if (io_opt_sectors < era->sectors_per_block || |
1736 | do_div(io_opt_sectors, era->sectors_per_block)) { |
1737 | blk_limits_io_min(limits, min: 0); |
1738 | blk_limits_io_opt(limits, opt: era->sectors_per_block << SECTOR_SHIFT); |
1739 | } |
1740 | } |
1741 | |
1742 | /*----------------------------------------------------------------*/ |
1743 | |
1744 | static struct target_type era_target = { |
1745 | .name = "era" , |
1746 | .version = {1, 0, 0}, |
1747 | .module = THIS_MODULE, |
1748 | .ctr = era_ctr, |
1749 | .dtr = era_dtr, |
1750 | .map = era_map, |
1751 | .postsuspend = era_postsuspend, |
1752 | .preresume = era_preresume, |
1753 | .status = era_status, |
1754 | .message = era_message, |
1755 | .iterate_devices = era_iterate_devices, |
1756 | .io_hints = era_io_hints |
1757 | }; |
1758 | module_dm(era); |
1759 | |
1760 | MODULE_DESCRIPTION(DM_NAME " era target" ); |
1761 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>" ); |
1762 | MODULE_LICENSE("GPL" ); |
1763 | |