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-rw-r--r--drivers/md/dm-thin-metadata.c1391
1 files changed, 1391 insertions, 0 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
new file mode 100644
index 00000000000..59c4f0446ff
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+++ b/drivers/md/dm-thin-metadata.c
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1/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm-thin-metadata.h"
8#include "persistent-data/dm-btree.h"
9#include "persistent-data/dm-space-map.h"
10#include "persistent-data/dm-space-map-disk.h"
11#include "persistent-data/dm-transaction-manager.h"
12
13#include <linux/list.h>
14#include <linux/device-mapper.h>
15#include <linux/workqueue.h>
16
17/*--------------------------------------------------------------------------
18 * As far as the metadata goes, there is:
19 *
20 * - A superblock in block zero, taking up fewer than 512 bytes for
21 * atomic writes.
22 *
23 * - A space map managing the metadata blocks.
24 *
25 * - A space map managing the data blocks.
26 *
27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
28 *
29 * - A hierarchical btree, with 2 levels which effectively maps (thin
30 * dev id, virtual block) -> block_time. Block time is a 64-bit
31 * field holding the time in the low 24 bits, and block in the top 48
32 * bits.
33 *
34 * BTrees consist solely of btree_nodes, that fill a block. Some are
35 * internal nodes, as such their values are a __le64 pointing to other
36 * nodes. Leaf nodes can store data of any reasonable size (ie. much
37 * smaller than the block size). The nodes consist of the header,
38 * followed by an array of keys, followed by an array of values. We have
39 * to binary search on the keys so they're all held together to help the
40 * cpu cache.
41 *
42 * Space maps have 2 btrees:
43 *
44 * - One maps a uint64_t onto a struct index_entry. Which points to a
45 * bitmap block, and has some details about how many free entries there
46 * are etc.
47 *
48 * - The bitmap blocks have a header (for the checksum). Then the rest
49 * of the block is pairs of bits. With the meaning being:
50 *
51 * 0 - ref count is 0
52 * 1 - ref count is 1
53 * 2 - ref count is 2
54 * 3 - ref count is higher than 2
55 *
56 * - If the count is higher than 2 then the ref count is entered in a
57 * second btree that directly maps the block_address to a uint32_t ref
58 * count.
59 *
60 * The space map metadata variant doesn't have a bitmaps btree. Instead
61 * it has one single blocks worth of index_entries. This avoids
62 * recursive issues with the bitmap btree needing to allocate space in
63 * order to insert. With a small data block size such as 64k the
64 * metadata support data devices that are hundreds of terrabytes.
65 *
66 * The space maps allocate space linearly from front to back. Space that
67 * is freed in a transaction is never recycled within that transaction.
68 * To try and avoid fragmenting _free_ space the allocator always goes
69 * back and fills in gaps.
70 *
71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
72 * from the block manager.
73 *--------------------------------------------------------------------------*/
74
75#define DM_MSG_PREFIX "thin metadata"
76
77#define THIN_SUPERBLOCK_MAGIC 27022010
78#define THIN_SUPERBLOCK_LOCATION 0
79#define THIN_VERSION 1
80#define THIN_METADATA_CACHE_SIZE 64
81#define SECTOR_TO_BLOCK_SHIFT 3
82
83/* This should be plenty */
84#define SPACE_MAP_ROOT_SIZE 128
85
86/*
87 * Little endian on-disk superblock and device details.
88 */
89struct thin_disk_superblock {
90 __le32 csum; /* Checksum of superblock except for this field. */
91 __le32 flags;
92 __le64 blocknr; /* This block number, dm_block_t. */
93
94 __u8 uuid[16];
95 __le64 magic;
96 __le32 version;
97 __le32 time;
98
99 __le64 trans_id;
100
101 /*
102 * Root held by userspace transactions.
103 */
104 __le64 held_root;
105
106 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
107 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
108
109 /*
110 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
111 */
112 __le64 data_mapping_root;
113
114 /*
115 * Device detail root mapping dev_id -> device_details
116 */
117 __le64 device_details_root;
118
119 __le32 data_block_size; /* In 512-byte sectors. */
120
121 __le32 metadata_block_size; /* In 512-byte sectors. */
122 __le64 metadata_nr_blocks;
123
124 __le32 compat_flags;
125 __le32 compat_ro_flags;
126 __le32 incompat_flags;
127} __packed;
128
129struct disk_device_details {
130 __le64 mapped_blocks;
131 __le64 transaction_id; /* When created. */
132 __le32 creation_time;
133 __le32 snapshotted_time;
134} __packed;
135
136struct dm_pool_metadata {
137 struct hlist_node hash;
138
139 struct block_device *bdev;
140 struct dm_block_manager *bm;
141 struct dm_space_map *metadata_sm;
142 struct dm_space_map *data_sm;
143 struct dm_transaction_manager *tm;
144 struct dm_transaction_manager *nb_tm;
145
146 /*
147 * Two-level btree.
148 * First level holds thin_dev_t.
149 * Second level holds mappings.
150 */
151 struct dm_btree_info info;
152
153 /*
154 * Non-blocking version of the above.
155 */
156 struct dm_btree_info nb_info;
157
158 /*
159 * Just the top level for deleting whole devices.
160 */
161 struct dm_btree_info tl_info;
162
163 /*
164 * Just the bottom level for creating new devices.
165 */
166 struct dm_btree_info bl_info;
167
168 /*
169 * Describes the device details btree.
170 */
171 struct dm_btree_info details_info;
172
173 struct rw_semaphore root_lock;
174 uint32_t time;
175 int need_commit;
176 dm_block_t root;
177 dm_block_t details_root;
178 struct list_head thin_devices;
179 uint64_t trans_id;
180 unsigned long flags;
181 sector_t data_block_size;
182};
183
184struct dm_thin_device {
185 struct list_head list;
186 struct dm_pool_metadata *pmd;
187 dm_thin_id id;
188
189 int open_count;
190 int changed;
191 uint64_t mapped_blocks;
192 uint64_t transaction_id;
193 uint32_t creation_time;
194 uint32_t snapshotted_time;
195};
196
197/*----------------------------------------------------------------
198 * superblock validator
199 *--------------------------------------------------------------*/
200
201#define SUPERBLOCK_CSUM_XOR 160774
202
203static void sb_prepare_for_write(struct dm_block_validator *v,
204 struct dm_block *b,
205 size_t block_size)
206{
207 struct thin_disk_superblock *disk_super = dm_block_data(b);
208
209 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
210 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
211 block_size - sizeof(__le32),
212 SUPERBLOCK_CSUM_XOR));
213}
214
215static int sb_check(struct dm_block_validator *v,
216 struct dm_block *b,
217 size_t block_size)
218{
219 struct thin_disk_superblock *disk_super = dm_block_data(b);
220 __le32 csum_le;
221
222 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
223 DMERR("sb_check failed: blocknr %llu: "
224 "wanted %llu", le64_to_cpu(disk_super->blocknr),
225 (unsigned long long)dm_block_location(b));
226 return -ENOTBLK;
227 }
228
229 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
230 DMERR("sb_check failed: magic %llu: "
231 "wanted %llu", le64_to_cpu(disk_super->magic),
232 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
233 return -EILSEQ;
234 }
235
236 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
237 block_size - sizeof(__le32),
238 SUPERBLOCK_CSUM_XOR));
239 if (csum_le != disk_super->csum) {
240 DMERR("sb_check failed: csum %u: wanted %u",
241 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
242 return -EILSEQ;
243 }
244
245 return 0;
246}
247
248static struct dm_block_validator sb_validator = {
249 .name = "superblock",
250 .prepare_for_write = sb_prepare_for_write,
251 .check = sb_check
252};
253
254/*----------------------------------------------------------------
255 * Methods for the btree value types
256 *--------------------------------------------------------------*/
257
258static uint64_t pack_block_time(dm_block_t b, uint32_t t)
259{
260 return (b << 24) | t;
261}
262
263static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
264{
265 *b = v >> 24;
266 *t = v & ((1 << 24) - 1);
267}
268
269static void data_block_inc(void *context, void *value_le)
270{
271 struct dm_space_map *sm = context;
272 __le64 v_le;
273 uint64_t b;
274 uint32_t t;
275
276 memcpy(&v_le, value_le, sizeof(v_le));
277 unpack_block_time(le64_to_cpu(v_le), &b, &t);
278 dm_sm_inc_block(sm, b);
279}
280
281static void data_block_dec(void *context, void *value_le)
282{
283 struct dm_space_map *sm = context;
284 __le64 v_le;
285 uint64_t b;
286 uint32_t t;
287
288 memcpy(&v_le, value_le, sizeof(v_le));
289 unpack_block_time(le64_to_cpu(v_le), &b, &t);
290 dm_sm_dec_block(sm, b);
291}
292
293static int data_block_equal(void *context, void *value1_le, void *value2_le)
294{
295 __le64 v1_le, v2_le;
296 uint64_t b1, b2;
297 uint32_t t;
298
299 memcpy(&v1_le, value1_le, sizeof(v1_le));
300 memcpy(&v2_le, value2_le, sizeof(v2_le));
301 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
302 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
303
304 return b1 == b2;
305}
306
307static void subtree_inc(void *context, void *value)
308{
309 struct dm_btree_info *info = context;
310 __le64 root_le;
311 uint64_t root;
312
313 memcpy(&root_le, value, sizeof(root_le));
314 root = le64_to_cpu(root_le);
315 dm_tm_inc(info->tm, root);
316}
317
318static void subtree_dec(void *context, void *value)
319{
320 struct dm_btree_info *info = context;
321 __le64 root_le;
322 uint64_t root;
323
324 memcpy(&root_le, value, sizeof(root_le));
325 root = le64_to_cpu(root_le);
326 if (dm_btree_del(info, root))
327 DMERR("btree delete failed\n");
328}
329
330static int subtree_equal(void *context, void *value1_le, void *value2_le)
331{
332 __le64 v1_le, v2_le;
333 memcpy(&v1_le, value1_le, sizeof(v1_le));
334 memcpy(&v2_le, value2_le, sizeof(v2_le));
335
336 return v1_le == v2_le;
337}
338
339/*----------------------------------------------------------------*/
340
341static int superblock_all_zeroes(struct dm_block_manager *bm, int *result)
342{
343 int r;
344 unsigned i;
345 struct dm_block *b;
346 __le64 *data_le, zero = cpu_to_le64(0);
347 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
348
349 /*
350 * We can't use a validator here - it may be all zeroes.
351 */
352 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
353 if (r)
354 return r;
355
356 data_le = dm_block_data(b);
357 *result = 1;
358 for (i = 0; i < block_size; i++) {
359 if (data_le[i] != zero) {
360 *result = 0;
361 break;
362 }
363 }
364
365 return dm_bm_unlock(b);
366}
367
368static int init_pmd(struct dm_pool_metadata *pmd,
369 struct dm_block_manager *bm,
370 dm_block_t nr_blocks, int create)
371{
372 int r;
373 struct dm_space_map *sm, *data_sm;
374 struct dm_transaction_manager *tm;
375 struct dm_block *sblock;
376
377 if (create) {
378 r = dm_tm_create_with_sm(bm, THIN_SUPERBLOCK_LOCATION,
379 &sb_validator, &tm, &sm, &sblock);
380 if (r < 0) {
381 DMERR("tm_create_with_sm failed");
382 return r;
383 }
384
385 data_sm = dm_sm_disk_create(tm, nr_blocks);
386 if (IS_ERR(data_sm)) {
387 DMERR("sm_disk_create failed");
388 r = PTR_ERR(data_sm);
389 goto bad;
390 }
391 } else {
392 struct thin_disk_superblock *disk_super = NULL;
393 size_t space_map_root_offset =
394 offsetof(struct thin_disk_superblock, metadata_space_map_root);
395
396 r = dm_tm_open_with_sm(bm, THIN_SUPERBLOCK_LOCATION,
397 &sb_validator, space_map_root_offset,
398 SPACE_MAP_ROOT_SIZE, &tm, &sm, &sblock);
399 if (r < 0) {
400 DMERR("tm_open_with_sm failed");
401 return r;
402 }
403
404 disk_super = dm_block_data(sblock);
405 data_sm = dm_sm_disk_open(tm, disk_super->data_space_map_root,
406 sizeof(disk_super->data_space_map_root));
407 if (IS_ERR(data_sm)) {
408 DMERR("sm_disk_open failed");
409 r = PTR_ERR(data_sm);
410 goto bad;
411 }
412 }
413
414
415 r = dm_tm_unlock(tm, sblock);
416 if (r < 0) {
417 DMERR("couldn't unlock superblock");
418 goto bad_data_sm;
419 }
420
421 pmd->bm = bm;
422 pmd->metadata_sm = sm;
423 pmd->data_sm = data_sm;
424 pmd->tm = tm;
425 pmd->nb_tm = dm_tm_create_non_blocking_clone(tm);
426 if (!pmd->nb_tm) {
427 DMERR("could not create clone tm");
428 r = -ENOMEM;
429 goto bad_data_sm;
430 }
431
432 pmd->info.tm = tm;
433 pmd->info.levels = 2;
434 pmd->info.value_type.context = pmd->data_sm;
435 pmd->info.value_type.size = sizeof(__le64);
436 pmd->info.value_type.inc = data_block_inc;
437 pmd->info.value_type.dec = data_block_dec;
438 pmd->info.value_type.equal = data_block_equal;
439
440 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
441 pmd->nb_info.tm = pmd->nb_tm;
442
443 pmd->tl_info.tm = tm;
444 pmd->tl_info.levels = 1;
445 pmd->tl_info.value_type.context = &pmd->info;
446 pmd->tl_info.value_type.size = sizeof(__le64);
447 pmd->tl_info.value_type.inc = subtree_inc;
448 pmd->tl_info.value_type.dec = subtree_dec;
449 pmd->tl_info.value_type.equal = subtree_equal;
450
451 pmd->bl_info.tm = tm;
452 pmd->bl_info.levels = 1;
453 pmd->bl_info.value_type.context = pmd->data_sm;
454 pmd->bl_info.value_type.size = sizeof(__le64);
455 pmd->bl_info.value_type.inc = data_block_inc;
456 pmd->bl_info.value_type.dec = data_block_dec;
457 pmd->bl_info.value_type.equal = data_block_equal;
458
459 pmd->details_info.tm = tm;
460 pmd->details_info.levels = 1;
461 pmd->details_info.value_type.context = NULL;
462 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
463 pmd->details_info.value_type.inc = NULL;
464 pmd->details_info.value_type.dec = NULL;
465 pmd->details_info.value_type.equal = NULL;
466
467 pmd->root = 0;
468
469 init_rwsem(&pmd->root_lock);
470 pmd->time = 0;
471 pmd->need_commit = 0;
472 pmd->details_root = 0;
473 pmd->trans_id = 0;
474 pmd->flags = 0;
475 INIT_LIST_HEAD(&pmd->thin_devices);
476
477 return 0;
478
479bad_data_sm:
480 dm_sm_destroy(data_sm);
481bad:
482 dm_tm_destroy(tm);
483 dm_sm_destroy(sm);
484
485 return r;
486}
487
488static int __begin_transaction(struct dm_pool_metadata *pmd)
489{
490 int r;
491 u32 features;
492 struct thin_disk_superblock *disk_super;
493 struct dm_block *sblock;
494
495 /*
496 * __maybe_commit_transaction() resets these
497 */
498 WARN_ON(pmd->need_commit);
499
500 /*
501 * We re-read the superblock every time. Shouldn't need to do this
502 * really.
503 */
504 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
505 &sb_validator, &sblock);
506 if (r)
507 return r;
508
509 disk_super = dm_block_data(sblock);
510 pmd->time = le32_to_cpu(disk_super->time);
511 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
512 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
513 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
514 pmd->flags = le32_to_cpu(disk_super->flags);
515 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
516
517 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
518 if (features) {
519 DMERR("could not access metadata due to "
520 "unsupported optional features (%lx).",
521 (unsigned long)features);
522 r = -EINVAL;
523 goto out;
524 }
525
526 /*
527 * Check for read-only metadata to skip the following RDWR checks.
528 */
529 if (get_disk_ro(pmd->bdev->bd_disk))
530 goto out;
531
532 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
533 if (features) {
534 DMERR("could not access metadata RDWR due to "
535 "unsupported optional features (%lx).",
536 (unsigned long)features);
537 r = -EINVAL;
538 }
539
540out:
541 dm_bm_unlock(sblock);
542 return r;
543}
544
545static int __write_changed_details(struct dm_pool_metadata *pmd)
546{
547 int r;
548 struct dm_thin_device *td, *tmp;
549 struct disk_device_details details;
550 uint64_t key;
551
552 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
553 if (!td->changed)
554 continue;
555
556 key = td->id;
557
558 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
559 details.transaction_id = cpu_to_le64(td->transaction_id);
560 details.creation_time = cpu_to_le32(td->creation_time);
561 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
562 __dm_bless_for_disk(&details);
563
564 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
565 &key, &details, &pmd->details_root);
566 if (r)
567 return r;
568
569 if (td->open_count)
570 td->changed = 0;
571 else {
572 list_del(&td->list);
573 kfree(td);
574 }
575
576 pmd->need_commit = 1;
577 }
578
579 return 0;
580}
581
582static int __commit_transaction(struct dm_pool_metadata *pmd)
583{
584 /*
585 * FIXME: Associated pool should be made read-only on failure.
586 */
587 int r;
588 size_t metadata_len, data_len;
589 struct thin_disk_superblock *disk_super;
590 struct dm_block *sblock;
591
592 /*
593 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
594 */
595 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
596
597 r = __write_changed_details(pmd);
598 if (r < 0)
599 goto out;
600
601 if (!pmd->need_commit)
602 goto out;
603
604 r = dm_sm_commit(pmd->data_sm);
605 if (r < 0)
606 goto out;
607
608 r = dm_tm_pre_commit(pmd->tm);
609 if (r < 0)
610 goto out;
611
612 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
613 if (r < 0)
614 goto out;
615
616 r = dm_sm_root_size(pmd->metadata_sm, &data_len);
617 if (r < 0)
618 goto out;
619
620 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
621 &sb_validator, &sblock);
622 if (r)
623 goto out;
624
625 disk_super = dm_block_data(sblock);
626 disk_super->time = cpu_to_le32(pmd->time);
627 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
628 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
629 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
630 disk_super->flags = cpu_to_le32(pmd->flags);
631
632 r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
633 metadata_len);
634 if (r < 0)
635 goto out_locked;
636
637 r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
638 data_len);
639 if (r < 0)
640 goto out_locked;
641
642 r = dm_tm_commit(pmd->tm, sblock);
643 if (!r)
644 pmd->need_commit = 0;
645
646out:
647 return r;
648
649out_locked:
650 dm_bm_unlock(sblock);
651 return r;
652}
653
654struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
655 sector_t data_block_size)
656{
657 int r;
658 struct thin_disk_superblock *disk_super;
659 struct dm_pool_metadata *pmd;
660 sector_t bdev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
661 struct dm_block_manager *bm;
662 int create;
663 struct dm_block *sblock;
664
665 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
666 if (!pmd) {
667 DMERR("could not allocate metadata struct");
668 return ERR_PTR(-ENOMEM);
669 }
670
671 /*
672 * Max hex locks:
673 * 3 for btree insert +
674 * 2 for btree lookup used within space map
675 */
676 bm = dm_block_manager_create(bdev, THIN_METADATA_BLOCK_SIZE,
677 THIN_METADATA_CACHE_SIZE, 5);
678 if (!bm) {
679 DMERR("could not create block manager");
680 kfree(pmd);
681 return ERR_PTR(-ENOMEM);
682 }
683
684 r = superblock_all_zeroes(bm, &create);
685 if (r) {
686 dm_block_manager_destroy(bm);
687 kfree(pmd);
688 return ERR_PTR(r);
689 }
690
691
692 r = init_pmd(pmd, bm, 0, create);
693 if (r) {
694 dm_block_manager_destroy(bm);
695 kfree(pmd);
696 return ERR_PTR(r);
697 }
698 pmd->bdev = bdev;
699
700 if (!create) {
701 r = __begin_transaction(pmd);
702 if (r < 0)
703 goto bad;
704 return pmd;
705 }
706
707 /*
708 * Create.
709 */
710 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
711 &sb_validator, &sblock);
712 if (r)
713 goto bad;
714
715 disk_super = dm_block_data(sblock);
716 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
717 disk_super->version = cpu_to_le32(THIN_VERSION);
718 disk_super->time = 0;
719 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
720 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
721 disk_super->data_block_size = cpu_to_le32(data_block_size);
722
723 r = dm_bm_unlock(sblock);
724 if (r < 0)
725 goto bad;
726
727 r = dm_btree_empty(&pmd->info, &pmd->root);
728 if (r < 0)
729 goto bad;
730
731 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
732 if (r < 0) {
733 DMERR("couldn't create devices root");
734 goto bad;
735 }
736
737 pmd->flags = 0;
738 pmd->need_commit = 1;
739 r = dm_pool_commit_metadata(pmd);
740 if (r < 0) {
741 DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
742 __func__, r);
743 goto bad;
744 }
745
746 return pmd;
747
748bad:
749 if (dm_pool_metadata_close(pmd) < 0)
750 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
751 return ERR_PTR(r);
752}
753
754int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
755{
756 int r;
757 unsigned open_devices = 0;
758 struct dm_thin_device *td, *tmp;
759
760 down_read(&pmd->root_lock);
761 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
762 if (td->open_count)
763 open_devices++;
764 else {
765 list_del(&td->list);
766 kfree(td);
767 }
768 }
769 up_read(&pmd->root_lock);
770
771 if (open_devices) {
772 DMERR("attempt to close pmd when %u device(s) are still open",
773 open_devices);
774 return -EBUSY;
775 }
776
777 r = __commit_transaction(pmd);
778 if (r < 0)
779 DMWARN("%s: __commit_transaction() failed, error = %d",
780 __func__, r);
781
782 dm_tm_destroy(pmd->tm);
783 dm_tm_destroy(pmd->nb_tm);
784 dm_block_manager_destroy(pmd->bm);
785 dm_sm_destroy(pmd->metadata_sm);
786 dm_sm_destroy(pmd->data_sm);
787 kfree(pmd);
788
789 return 0;
790}
791
792static int __open_device(struct dm_pool_metadata *pmd,
793 dm_thin_id dev, int create,
794 struct dm_thin_device **td)
795{
796 int r, changed = 0;
797 struct dm_thin_device *td2;
798 uint64_t key = dev;
799 struct disk_device_details details_le;
800
801 /*
802 * Check the device isn't already open.
803 */
804 list_for_each_entry(td2, &pmd->thin_devices, list)
805 if (td2->id == dev) {
806 td2->open_count++;
807 *td = td2;
808 return 0;
809 }
810
811 /*
812 * Check the device exists.
813 */
814 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
815 &key, &details_le);
816 if (r) {
817 if (r != -ENODATA || !create)
818 return r;
819
820 changed = 1;
821 details_le.mapped_blocks = 0;
822 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
823 details_le.creation_time = cpu_to_le32(pmd->time);
824 details_le.snapshotted_time = cpu_to_le32(pmd->time);
825 }
826
827 *td = kmalloc(sizeof(**td), GFP_NOIO);
828 if (!*td)
829 return -ENOMEM;
830
831 (*td)->pmd = pmd;
832 (*td)->id = dev;
833 (*td)->open_count = 1;
834 (*td)->changed = changed;
835 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
836 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
837 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
838 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
839
840 list_add(&(*td)->list, &pmd->thin_devices);
841
842 return 0;
843}
844
845static void __close_device(struct dm_thin_device *td)
846{
847 --td->open_count;
848}
849
850static int __create_thin(struct dm_pool_metadata *pmd,
851 dm_thin_id dev)
852{
853 int r;
854 dm_block_t dev_root;
855 uint64_t key = dev;
856 struct disk_device_details details_le;
857 struct dm_thin_device *td;
858 __le64 value;
859
860 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
861 &key, &details_le);
862 if (!r)
863 return -EEXIST;
864
865 /*
866 * Create an empty btree for the mappings.
867 */
868 r = dm_btree_empty(&pmd->bl_info, &dev_root);
869 if (r)
870 return r;
871
872 /*
873 * Insert it into the main mapping tree.
874 */
875 value = cpu_to_le64(dev_root);
876 __dm_bless_for_disk(&value);
877 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
878 if (r) {
879 dm_btree_del(&pmd->bl_info, dev_root);
880 return r;
881 }
882
883 r = __open_device(pmd, dev, 1, &td);
884 if (r) {
885 __close_device(td);
886 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
887 dm_btree_del(&pmd->bl_info, dev_root);
888 return r;
889 }
890 td->changed = 1;
891 __close_device(td);
892
893 return r;
894}
895
896int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
897{
898 int r;
899
900 down_write(&pmd->root_lock);
901 r = __create_thin(pmd, dev);
902 up_write(&pmd->root_lock);
903
904 return r;
905}
906
907static int __set_snapshot_details(struct dm_pool_metadata *pmd,
908 struct dm_thin_device *snap,
909 dm_thin_id origin, uint32_t time)
910{
911 int r;
912 struct dm_thin_device *td;
913
914 r = __open_device(pmd, origin, 0, &td);
915 if (r)
916 return r;
917
918 td->changed = 1;
919 td->snapshotted_time = time;
920
921 snap->mapped_blocks = td->mapped_blocks;
922 snap->snapshotted_time = time;
923 __close_device(td);
924
925 return 0;
926}
927
928static int __create_snap(struct dm_pool_metadata *pmd,
929 dm_thin_id dev, dm_thin_id origin)
930{
931 int r;
932 dm_block_t origin_root;
933 uint64_t key = origin, dev_key = dev;
934 struct dm_thin_device *td;
935 struct disk_device_details details_le;
936 __le64 value;
937
938 /* check this device is unused */
939 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
940 &dev_key, &details_le);
941 if (!r)
942 return -EEXIST;
943
944 /* find the mapping tree for the origin */
945 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
946 if (r)
947 return r;
948 origin_root = le64_to_cpu(value);
949
950 /* clone the origin, an inc will do */
951 dm_tm_inc(pmd->tm, origin_root);
952
953 /* insert into the main mapping tree */
954 value = cpu_to_le64(origin_root);
955 __dm_bless_for_disk(&value);
956 key = dev;
957 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
958 if (r) {
959 dm_tm_dec(pmd->tm, origin_root);
960 return r;
961 }
962
963 pmd->time++;
964
965 r = __open_device(pmd, dev, 1, &td);
966 if (r)
967 goto bad;
968
969 r = __set_snapshot_details(pmd, td, origin, pmd->time);
970 if (r)
971 goto bad;
972
973 __close_device(td);
974 return 0;
975
976bad:
977 __close_device(td);
978 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
979 dm_btree_remove(&pmd->details_info, pmd->details_root,
980 &key, &pmd->details_root);
981 return r;
982}
983
984int dm_pool_create_snap(struct dm_pool_metadata *pmd,
985 dm_thin_id dev,
986 dm_thin_id origin)
987{
988 int r;
989
990 down_write(&pmd->root_lock);
991 r = __create_snap(pmd, dev, origin);
992 up_write(&pmd->root_lock);
993
994 return r;
995}
996
997static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
998{
999 int r;
1000 uint64_t key = dev;
1001 struct dm_thin_device *td;
1002
1003 /* TODO: failure should mark the transaction invalid */
1004 r = __open_device(pmd, dev, 0, &td);
1005 if (r)
1006 return r;
1007
1008 if (td->open_count > 1) {
1009 __close_device(td);
1010 return -EBUSY;
1011 }
1012
1013 list_del(&td->list);
1014 kfree(td);
1015 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1016 &key, &pmd->details_root);
1017 if (r)
1018 return r;
1019
1020 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1021 if (r)
1022 return r;
1023
1024 pmd->need_commit = 1;
1025
1026 return 0;
1027}
1028
1029int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1030 dm_thin_id dev)
1031{
1032 int r;
1033
1034 down_write(&pmd->root_lock);
1035 r = __delete_device(pmd, dev);
1036 up_write(&pmd->root_lock);
1037
1038 return r;
1039}
1040
1041int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1042 uint64_t current_id,
1043 uint64_t new_id)
1044{
1045 down_write(&pmd->root_lock);
1046 if (pmd->trans_id != current_id) {
1047 up_write(&pmd->root_lock);
1048 DMERR("mismatched transaction id");
1049 return -EINVAL;
1050 }
1051
1052 pmd->trans_id = new_id;
1053 pmd->need_commit = 1;
1054 up_write(&pmd->root_lock);
1055
1056 return 0;
1057}
1058
1059int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1060 uint64_t *result)
1061{
1062 down_read(&pmd->root_lock);
1063 *result = pmd->trans_id;
1064 up_read(&pmd->root_lock);
1065
1066 return 0;
1067}
1068
1069static int __get_held_metadata_root(struct dm_pool_metadata *pmd,
1070 dm_block_t *result)
1071{
1072 int r;
1073 struct thin_disk_superblock *disk_super;
1074 struct dm_block *sblock;
1075
1076 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1077 &sb_validator, &sblock);
1078 if (r)
1079 return r;
1080
1081 disk_super = dm_block_data(sblock);
1082 *result = le64_to_cpu(disk_super->held_root);
1083
1084 return dm_bm_unlock(sblock);
1085}
1086
1087int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd,
1088 dm_block_t *result)
1089{
1090 int r;
1091
1092 down_read(&pmd->root_lock);
1093 r = __get_held_metadata_root(pmd, result);
1094 up_read(&pmd->root_lock);
1095
1096 return r;
1097}
1098
1099int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1100 struct dm_thin_device **td)
1101{
1102 int r;
1103
1104 down_write(&pmd->root_lock);
1105 r = __open_device(pmd, dev, 0, td);
1106 up_write(&pmd->root_lock);
1107
1108 return r;
1109}
1110
1111int dm_pool_close_thin_device(struct dm_thin_device *td)
1112{
1113 down_write(&td->pmd->root_lock);
1114 __close_device(td);
1115 up_write(&td->pmd->root_lock);
1116
1117 return 0;
1118}
1119
1120dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1121{
1122 return td->id;
1123}
1124
1125static int __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1126{
1127 return td->snapshotted_time > time;
1128}
1129
1130int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1131 int can_block, struct dm_thin_lookup_result *result)
1132{
1133 int r;
1134 uint64_t block_time = 0;
1135 __le64 value;
1136 struct dm_pool_metadata *pmd = td->pmd;
1137 dm_block_t keys[2] = { td->id, block };
1138
1139 if (can_block) {
1140 down_read(&pmd->root_lock);
1141 r = dm_btree_lookup(&pmd->info, pmd->root, keys, &value);
1142 if (!r)
1143 block_time = le64_to_cpu(value);
1144 up_read(&pmd->root_lock);
1145
1146 } else if (down_read_trylock(&pmd->root_lock)) {
1147 r = dm_btree_lookup(&pmd->nb_info, pmd->root, keys, &value);
1148 if (!r)
1149 block_time = le64_to_cpu(value);
1150 up_read(&pmd->root_lock);
1151
1152 } else
1153 return -EWOULDBLOCK;
1154
1155 if (!r) {
1156 dm_block_t exception_block;
1157 uint32_t exception_time;
1158 unpack_block_time(block_time, &exception_block,
1159 &exception_time);
1160 result->block = exception_block;
1161 result->shared = __snapshotted_since(td, exception_time);
1162 }
1163
1164 return r;
1165}
1166
1167static int __insert(struct dm_thin_device *td, dm_block_t block,
1168 dm_block_t data_block)
1169{
1170 int r, inserted;
1171 __le64 value;
1172 struct dm_pool_metadata *pmd = td->pmd;
1173 dm_block_t keys[2] = { td->id, block };
1174
1175 pmd->need_commit = 1;
1176 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1177 __dm_bless_for_disk(&value);
1178
1179 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1180 &pmd->root, &inserted);
1181 if (r)
1182 return r;
1183
1184 if (inserted) {
1185 td->mapped_blocks++;
1186 td->changed = 1;
1187 }
1188
1189 return 0;
1190}
1191
1192int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1193 dm_block_t data_block)
1194{
1195 int r;
1196
1197 down_write(&td->pmd->root_lock);
1198 r = __insert(td, block, data_block);
1199 up_write(&td->pmd->root_lock);
1200
1201 return r;
1202}
1203
1204static int __remove(struct dm_thin_device *td, dm_block_t block)
1205{
1206 int r;
1207 struct dm_pool_metadata *pmd = td->pmd;
1208 dm_block_t keys[2] = { td->id, block };
1209
1210 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1211 if (r)
1212 return r;
1213
1214 pmd->need_commit = 1;
1215
1216 return 0;
1217}
1218
1219int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1220{
1221 int r;
1222
1223 down_write(&td->pmd->root_lock);
1224 r = __remove(td, block);
1225 up_write(&td->pmd->root_lock);
1226
1227 return r;
1228}
1229
1230int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1231{
1232 int r;
1233
1234 down_write(&pmd->root_lock);
1235
1236 r = dm_sm_new_block(pmd->data_sm, result);
1237 pmd->need_commit = 1;
1238
1239 up_write(&pmd->root_lock);
1240
1241 return r;
1242}
1243
1244int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1245{
1246 int r;
1247
1248 down_write(&pmd->root_lock);
1249
1250 r = __commit_transaction(pmd);
1251 if (r <= 0)
1252 goto out;
1253
1254 /*
1255 * Open the next transaction.
1256 */
1257 r = __begin_transaction(pmd);
1258out:
1259 up_write(&pmd->root_lock);
1260 return r;
1261}
1262
1263int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1264{
1265 int r;
1266
1267 down_read(&pmd->root_lock);
1268 r = dm_sm_get_nr_free(pmd->data_sm, result);
1269 up_read(&pmd->root_lock);
1270
1271 return r;
1272}
1273
1274int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1275 dm_block_t *result)
1276{
1277 int r;
1278
1279 down_read(&pmd->root_lock);
1280 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1281 up_read(&pmd->root_lock);
1282
1283 return r;
1284}
1285
1286int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1287 dm_block_t *result)
1288{
1289 int r;
1290
1291 down_read(&pmd->root_lock);
1292 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1293 up_read(&pmd->root_lock);
1294
1295 return r;
1296}
1297
1298int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result)
1299{
1300 down_read(&pmd->root_lock);
1301 *result = pmd->data_block_size;
1302 up_read(&pmd->root_lock);
1303
1304 return 0;
1305}
1306
1307int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1308{
1309 int r;
1310
1311 down_read(&pmd->root_lock);
1312 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1313 up_read(&pmd->root_lock);
1314
1315 return r;
1316}
1317
1318int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1319{
1320 struct dm_pool_metadata *pmd = td->pmd;
1321
1322 down_read(&pmd->root_lock);
1323 *result = td->mapped_blocks;
1324 up_read(&pmd->root_lock);
1325
1326 return 0;
1327}
1328
1329static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1330{
1331 int r;
1332 __le64 value_le;
1333 dm_block_t thin_root;
1334 struct dm_pool_metadata *pmd = td->pmd;
1335
1336 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1337 if (r)
1338 return r;
1339
1340 thin_root = le64_to_cpu(value_le);
1341
1342 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1343}
1344
1345int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1346 dm_block_t *result)
1347{
1348 int r;
1349 struct dm_pool_metadata *pmd = td->pmd;
1350
1351 down_read(&pmd->root_lock);
1352 r = __highest_block(td, result);
1353 up_read(&pmd->root_lock);
1354
1355 return r;
1356}
1357
1358static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1359{
1360 int r;
1361 dm_block_t old_count;
1362
1363 r = dm_sm_get_nr_blocks(pmd->data_sm, &old_count);
1364 if (r)
1365 return r;
1366
1367 if (new_count == old_count)
1368 return 0;
1369
1370 if (new_count < old_count) {
1371 DMERR("cannot reduce size of data device");
1372 return -EINVAL;
1373 }
1374
1375 r = dm_sm_extend(pmd->data_sm, new_count - old_count);
1376 if (!r)
1377 pmd->need_commit = 1;
1378
1379 return r;
1380}
1381
1382int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1383{
1384 int r;
1385
1386 down_write(&pmd->root_lock);
1387 r = __resize_data_dev(pmd, new_count);
1388 up_write(&pmd->root_lock);
1389
1390 return r;
1391}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-30 14:30:38 -0500