1/*
2 * Copyright (C) 2011-2012 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 2
80#define SECTOR_TO_BLOCK_SHIFT 3
81
82/*
83 * For btree insert:
84 * 3 for btree insert +
85 * 2 for btree lookup used within space map
86 * For btree remove:
87 * 2 for shadow spine +
88 * 4 for rebalance 3 child node
89 */
90#define THIN_MAX_CONCURRENT_LOCKS 6
91
92/* This should be plenty */
93#define SPACE_MAP_ROOT_SIZE 128
94
95/*
96 * Little endian on-disk superblock and device details.
97 */
98struct thin_disk_superblock {
99 __le32 csum; /* Checksum of superblock except for this field. */
100 __le32 flags;
101 __le64 blocknr; /* This block number, dm_block_t. */
102
103 __u8 uuid[16];
104 __le64 magic;
105 __le32 version;
106 __le32 time;
107
108 __le64 trans_id;
109
110 /*
111 * Root held by userspace transactions.
112 */
113 __le64 held_root;
114
115 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
116 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
117
118 /*
119 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
120 */
121 __le64 data_mapping_root;
122
123 /*
124 * Device detail root mapping dev_id -> device_details
125 */
126 __le64 device_details_root;
127
128 __le32 data_block_size; /* In 512-byte sectors. */
129
130 __le32 metadata_block_size; /* In 512-byte sectors. */
131 __le64 metadata_nr_blocks;
132
133 __le32 compat_flags;
134 __le32 compat_ro_flags;
135 __le32 incompat_flags;
136} __packed;
137
138struct disk_device_details {
139 __le64 mapped_blocks;
140 __le64 transaction_id; /* When created. */
141 __le32 creation_time;
142 __le32 snapshotted_time;
143} __packed;
144
145struct dm_pool_metadata {
146 struct hlist_node hash;
147
148 struct block_device *bdev;
149 struct dm_block_manager *bm;
150 struct dm_space_map *metadata_sm;
151 struct dm_space_map *data_sm;
152 struct dm_transaction_manager *tm;
153 struct dm_transaction_manager *nb_tm;
154
155 /*
156 * Two-level btree.
157 * First level holds thin_dev_t.
158 * Second level holds mappings.
159 */
160 struct dm_btree_info info;
161
162 /*
163 * Non-blocking version of the above.
164 */
165 struct dm_btree_info nb_info;
166
167 /*
168 * Just the top level for deleting whole devices.
169 */
170 struct dm_btree_info tl_info;
171
172 /*
173 * Just the bottom level for creating new devices.
174 */
175 struct dm_btree_info bl_info;
176
177 /*
178 * Describes the device details btree.
179 */
180 struct dm_btree_info details_info;
181
182 struct rw_semaphore root_lock;
183 uint32_t time;
184 dm_block_t root;
185 dm_block_t details_root;
186 struct list_head thin_devices;
187 uint64_t trans_id;
188 unsigned long flags;
189 sector_t data_block_size;
190
191 /*
192 * We reserve a section of the metadata for commit overhead.
193 * All reported space does *not* include this.
194 */
195 dm_block_t metadata_reserve;
196
197 /*
198 * Set if a transaction has to be aborted but the attempt to roll back
199 * to the previous (good) transaction failed. The only pool metadata
200 * operation possible in this state is the closing of the device.
201 */
202 bool fail_io:1;
203
204 /*
205 * Reading the space map roots can fail, so we read it into these
206 * buffers before the superblock is locked and updated.
207 */
208 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
209 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
210};
211
212struct dm_thin_device {
213 struct list_head list;
214 struct dm_pool_metadata *pmd;
215 dm_thin_id id;
216
217 int open_count;
218 bool changed:1;
219 bool aborted_with_changes:1;
220 uint64_t mapped_blocks;
221 uint64_t transaction_id;
222 uint32_t creation_time;
223 uint32_t snapshotted_time;
224};
225
226/*----------------------------------------------------------------
227 * superblock validator
228 *--------------------------------------------------------------*/
229
230#define SUPERBLOCK_CSUM_XOR 160774
231
232static void sb_prepare_for_write(struct dm_block_validator *v,
233 struct dm_block *b,
234 size_t block_size)
235{
236 struct thin_disk_superblock *disk_super = dm_block_data(b);
237
238 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
239 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
240 block_size - sizeof(__le32),
241 SUPERBLOCK_CSUM_XOR));
242}
243
244static int sb_check(struct dm_block_validator *v,
245 struct dm_block *b,
246 size_t block_size)
247{
248 struct thin_disk_superblock *disk_super = dm_block_data(b);
249 __le32 csum_le;
250
251 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
252 DMERR("sb_check failed: blocknr %llu: "
253 "wanted %llu", le64_to_cpu(disk_super->blocknr),
254 (unsigned long long)dm_block_location(b));
255 return -ENOTBLK;
256 }
257
258 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
259 DMERR("sb_check failed: magic %llu: "
260 "wanted %llu", le64_to_cpu(disk_super->magic),
261 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
262 return -EILSEQ;
263 }
264
265 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
266 block_size - sizeof(__le32),
267 SUPERBLOCK_CSUM_XOR));
268 if (csum_le != disk_super->csum) {
269 DMERR("sb_check failed: csum %u: wanted %u",
270 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
271 return -EILSEQ;
272 }
273
274 return 0;
275}
276
277static struct dm_block_validator sb_validator = {
278 .name = "superblock",
279 .prepare_for_write = sb_prepare_for_write,
280 .check = sb_check
281};
282
283/*----------------------------------------------------------------
284 * Methods for the btree value types
285 *--------------------------------------------------------------*/
286
287static uint64_t pack_block_time(dm_block_t b, uint32_t t)
288{
289 return (b << 24) | t;
290}
291
292static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
293{
294 *b = v >> 24;
295 *t = v & ((1 << 24) - 1);
296}
297
298static void data_block_inc(void *context, const void *value_le)
299{
300 struct dm_space_map *sm = context;
301 __le64 v_le;
302 uint64_t b;
303 uint32_t t;
304
305 memcpy(&v_le, value_le, sizeof(v_le));
306 unpack_block_time(le64_to_cpu(v_le), &b, &t);
307 dm_sm_inc_block(sm, b);
308}
309
310static void data_block_dec(void *context, const void *value_le)
311{
312 struct dm_space_map *sm = context;
313 __le64 v_le;
314 uint64_t b;
315 uint32_t t;
316
317 memcpy(&v_le, value_le, sizeof(v_le));
318 unpack_block_time(le64_to_cpu(v_le), &b, &t);
319 dm_sm_dec_block(sm, b);
320}
321
322static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
323{
324 __le64 v1_le, v2_le;
325 uint64_t b1, b2;
326 uint32_t t;
327
328 memcpy(&v1_le, value1_le, sizeof(v1_le));
329 memcpy(&v2_le, value2_le, sizeof(v2_le));
330 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
331 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
332
333 return b1 == b2;
334}
335
336static void subtree_inc(void *context, const void *value)
337{
338 struct dm_btree_info *info = context;
339 __le64 root_le;
340 uint64_t root;
341
342 memcpy(&root_le, value, sizeof(root_le));
343 root = le64_to_cpu(root_le);
344 dm_tm_inc(info->tm, root);
345}
346
347static void subtree_dec(void *context, const void *value)
348{
349 struct dm_btree_info *info = context;
350 __le64 root_le;
351 uint64_t root;
352
353 memcpy(&root_le, value, sizeof(root_le));
354 root = le64_to_cpu(root_le);
355 if (dm_btree_del(info, root))
356 DMERR("btree delete failed");
357}
358
359static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
360{
361 __le64 v1_le, v2_le;
362 memcpy(&v1_le, value1_le, sizeof(v1_le));
363 memcpy(&v2_le, value2_le, sizeof(v2_le));
364
365 return v1_le == v2_le;
366}
367
368/*----------------------------------------------------------------*/
369
370static int superblock_lock_zero(struct dm_pool_metadata *pmd,
371 struct dm_block **sblock)
372{
373 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
374 &sb_validator, sblock);
375}
376
377static int superblock_lock(struct dm_pool_metadata *pmd,
378 struct dm_block **sblock)
379{
380 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
381 &sb_validator, sblock);
382}
383
384static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
385{
386 int r;
387 unsigned i;
388 struct dm_block *b;
389 __le64 *data_le, zero = cpu_to_le64(0);
390 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
391
392 /*
393 * We can't use a validator here - it may be all zeroes.
394 */
395 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
396 if (r)
397 return r;
398
399 data_le = dm_block_data(b);
400 *result = 1;
401 for (i = 0; i < block_size; i++) {
402 if (data_le[i] != zero) {
403 *result = 0;
404 break;
405 }
406 }
407
408 dm_bm_unlock(b);
409
410 return 0;
411}
412
413static void __setup_btree_details(struct dm_pool_metadata *pmd)
414{
415 pmd->info.tm = pmd->tm;
416 pmd->info.levels = 2;
417 pmd->info.value_type.context = pmd->data_sm;
418 pmd->info.value_type.size = sizeof(__le64);
419 pmd->info.value_type.inc = data_block_inc;
420 pmd->info.value_type.dec = data_block_dec;
421 pmd->info.value_type.equal = data_block_equal;
422
423 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
424 pmd->nb_info.tm = pmd->nb_tm;
425
426 pmd->tl_info.tm = pmd->tm;
427 pmd->tl_info.levels = 1;
428 pmd->tl_info.value_type.context = &pmd->bl_info;
429 pmd->tl_info.value_type.size = sizeof(__le64);
430 pmd->tl_info.value_type.inc = subtree_inc;
431 pmd->tl_info.value_type.dec = subtree_dec;
432 pmd->tl_info.value_type.equal = subtree_equal;
433
434 pmd->bl_info.tm = pmd->tm;
435 pmd->bl_info.levels = 1;
436 pmd->bl_info.value_type.context = pmd->data_sm;
437 pmd->bl_info.value_type.size = sizeof(__le64);
438 pmd->bl_info.value_type.inc = data_block_inc;
439 pmd->bl_info.value_type.dec = data_block_dec;
440 pmd->bl_info.value_type.equal = data_block_equal;
441
442 pmd->details_info.tm = pmd->tm;
443 pmd->details_info.levels = 1;
444 pmd->details_info.value_type.context = NULL;
445 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
446 pmd->details_info.value_type.inc = NULL;
447 pmd->details_info.value_type.dec = NULL;
448 pmd->details_info.value_type.equal = NULL;
449}
450
451static int save_sm_roots(struct dm_pool_metadata *pmd)
452{
453 int r;
454 size_t len;
455
456 r = dm_sm_root_size(pmd->metadata_sm, &len);
457 if (r < 0)
458 return r;
459
460 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
461 if (r < 0)
462 return r;
463
464 r = dm_sm_root_size(pmd->data_sm, &len);
465 if (r < 0)
466 return r;
467
468 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
469}
470
471static void copy_sm_roots(struct dm_pool_metadata *pmd,
472 struct thin_disk_superblock *disk)
473{
474 memcpy(&disk->metadata_space_map_root,
475 &pmd->metadata_space_map_root,
476 sizeof(pmd->metadata_space_map_root));
477
478 memcpy(&disk->data_space_map_root,
479 &pmd->data_space_map_root,
480 sizeof(pmd->data_space_map_root));
481}
482
483static int __write_initial_superblock(struct dm_pool_metadata *pmd)
484{
485 int r;
486 struct dm_block *sblock;
487 struct thin_disk_superblock *disk_super;
488 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
489
490 if (bdev_size > THIN_METADATA_MAX_SECTORS)
491 bdev_size = THIN_METADATA_MAX_SECTORS;
492
493 r = dm_sm_commit(pmd->data_sm);
494 if (r < 0)
495 return r;
496
497 r = dm_tm_pre_commit(pmd->tm);
498 if (r < 0)
499 return r;
500
501 r = save_sm_roots(pmd);
502 if (r < 0)
503 return r;
504
505 r = superblock_lock_zero(pmd, &sblock);
506 if (r)
507 return r;
508
509 disk_super = dm_block_data(sblock);
510 disk_super->flags = 0;
511 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
512 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
513 disk_super->version = cpu_to_le32(THIN_VERSION);
514 disk_super->time = 0;
515 disk_super->trans_id = 0;
516 disk_super->held_root = 0;
517
518 copy_sm_roots(pmd, disk_super);
519
520 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
521 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
522 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
523 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
524 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
525
526 return dm_tm_commit(pmd->tm, sblock);
527}
528
529static int __format_metadata(struct dm_pool_metadata *pmd)
530{
531 int r;
532
533 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
534 &pmd->tm, &pmd->metadata_sm);
535 if (r < 0) {
536 DMERR("tm_create_with_sm failed");
537 return r;
538 }
539
540 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
541 if (IS_ERR(pmd->data_sm)) {
542 DMERR("sm_disk_create failed");
543 r = PTR_ERR(pmd->data_sm);
544 goto bad_cleanup_tm;
545 }
546
547 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
548 if (!pmd->nb_tm) {
549 DMERR("could not create non-blocking clone tm");
550 r = -ENOMEM;
551 goto bad_cleanup_data_sm;
552 }
553
554 __setup_btree_details(pmd);
555
556 r = dm_btree_empty(&pmd->info, &pmd->root);
557 if (r < 0)
558 goto bad_cleanup_nb_tm;
559
560 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
561 if (r < 0) {
562 DMERR("couldn't create devices root");
563 goto bad_cleanup_nb_tm;
564 }
565
566 r = __write_initial_superblock(pmd);
567 if (r)
568 goto bad_cleanup_nb_tm;
569
570 return 0;
571
572bad_cleanup_nb_tm:
573 dm_tm_destroy(pmd->nb_tm);
574bad_cleanup_data_sm:
575 dm_sm_destroy(pmd->data_sm);
576bad_cleanup_tm:
577 dm_tm_destroy(pmd->tm);
578 dm_sm_destroy(pmd->metadata_sm);
579
580 return r;
581}
582
583static int __check_incompat_features(struct thin_disk_superblock *disk_super,
584 struct dm_pool_metadata *pmd)
585{
586 uint32_t features;
587
588 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
589 if (features) {
590 DMERR("could not access metadata due to unsupported optional features (%lx).",
591 (unsigned long)features);
592 return -EINVAL;
593 }
594
595 /*
596 * Check for read-only metadata to skip the following RDWR checks.
597 */
598 if (get_disk_ro(pmd->bdev->bd_disk))
599 return 0;
600
601 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
602 if (features) {
603 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
604 (unsigned long)features);
605 return -EINVAL;
606 }
607
608 return 0;
609}
610
611static int __open_metadata(struct dm_pool_metadata *pmd)
612{
613 int r;
614 struct dm_block *sblock;
615 struct thin_disk_superblock *disk_super;
616
617 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
618 &sb_validator, &sblock);
619 if (r < 0) {
620 DMERR("couldn't read superblock");
621 return r;
622 }
623
624 disk_super = dm_block_data(sblock);
625
626 /* Verify the data block size hasn't changed */
627 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
628 DMERR("changing the data block size (from %u to %llu) is not supported",
629 le32_to_cpu(disk_super->data_block_size),
630 (unsigned long long)pmd->data_block_size);
631 r = -EINVAL;
632 goto bad_unlock_sblock;
633 }
634
635 r = __check_incompat_features(disk_super, pmd);
636 if (r < 0)
637 goto bad_unlock_sblock;
638
639 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
640 disk_super->metadata_space_map_root,
641 sizeof(disk_super->metadata_space_map_root),
642 &pmd->tm, &pmd->metadata_sm);
643 if (r < 0) {
644 DMERR("tm_open_with_sm failed");
645 goto bad_unlock_sblock;
646 }
647
648 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
649 sizeof(disk_super->data_space_map_root));
650 if (IS_ERR(pmd->data_sm)) {
651 DMERR("sm_disk_open failed");
652 r = PTR_ERR(pmd->data_sm);
653 goto bad_cleanup_tm;
654 }
655
656 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
657 if (!pmd->nb_tm) {
658 DMERR("could not create non-blocking clone tm");
659 r = -ENOMEM;
660 goto bad_cleanup_data_sm;
661 }
662
663 __setup_btree_details(pmd);
664 dm_bm_unlock(sblock);
665
666 return 0;
667
668bad_cleanup_data_sm:
669 dm_sm_destroy(pmd->data_sm);
670bad_cleanup_tm:
671 dm_tm_destroy(pmd->tm);
672 dm_sm_destroy(pmd->metadata_sm);
673bad_unlock_sblock:
674 dm_bm_unlock(sblock);
675
676 return r;
677}
678
679static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
680{
681 int r, unformatted;
682
683 r = __superblock_all_zeroes(pmd->bm, &unformatted);
684 if (r)
685 return r;
686
687 if (unformatted)
688 return format_device ? __format_metadata(pmd) : -EPERM;
689
690 return __open_metadata(pmd);
691}
692
693static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
694{
695 int r;
696
697 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
698 THIN_MAX_CONCURRENT_LOCKS);
699 if (IS_ERR(pmd->bm)) {
700 DMERR("could not create block manager");
701 return PTR_ERR(pmd->bm);
702 }
703
704 r = __open_or_format_metadata(pmd, format_device);
705 if (r)
706 dm_block_manager_destroy(pmd->bm);
707
708 return r;
709}
710
711static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
712{
713 dm_sm_destroy(pmd->data_sm);
714 dm_sm_destroy(pmd->metadata_sm);
715 dm_tm_destroy(pmd->nb_tm);
716 dm_tm_destroy(pmd->tm);
717 dm_block_manager_destroy(pmd->bm);
718}
719
720static int __begin_transaction(struct dm_pool_metadata *pmd)
721{
722 int r;
723 struct thin_disk_superblock *disk_super;
724 struct dm_block *sblock;
725
726 /*
727 * We re-read the superblock every time. Shouldn't need to do this
728 * really.
729 */
730 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
731 &sb_validator, &sblock);
732 if (r)
733 return r;
734
735 disk_super = dm_block_data(sblock);
736 pmd->time = le32_to_cpu(disk_super->time);
737 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
738 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
739 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
740 pmd->flags = le32_to_cpu(disk_super->flags);
741 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
742
743 dm_bm_unlock(sblock);
744 return 0;
745}
746
747static int __write_changed_details(struct dm_pool_metadata *pmd)
748{
749 int r;
750 struct dm_thin_device *td, *tmp;
751 struct disk_device_details details;
752 uint64_t key;
753
754 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
755 if (!td->changed)
756 continue;
757
758 key = td->id;
759
760 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
761 details.transaction_id = cpu_to_le64(td->transaction_id);
762 details.creation_time = cpu_to_le32(td->creation_time);
763 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
764 __dm_bless_for_disk(&details);
765
766 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
767 &key, &details, &pmd->details_root);
768 if (r)
769 return r;
770
771 if (td->open_count)
772 td->changed = 0;
773 else {
774 list_del(&td->list);
775 kfree(td);
776 }
777 }
778
779 return 0;
780}
781
782static int __commit_transaction(struct dm_pool_metadata *pmd)
783{
784 int r;
785 struct thin_disk_superblock *disk_super;
786 struct dm_block *sblock;
787
788 /*
789 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
790 */
791 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
792
793 r = __write_changed_details(pmd);
794 if (r < 0)
795 return r;
796
797 r = dm_sm_commit(pmd->data_sm);
798 if (r < 0)
799 return r;
800
801 r = dm_tm_pre_commit(pmd->tm);
802 if (r < 0)
803 return r;
804
805 r = save_sm_roots(pmd);
806 if (r < 0)
807 return r;
808
809 r = superblock_lock(pmd, &sblock);
810 if (r)
811 return r;
812
813 disk_super = dm_block_data(sblock);
814 disk_super->time = cpu_to_le32(pmd->time);
815 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
816 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
817 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
818 disk_super->flags = cpu_to_le32(pmd->flags);
819
820 copy_sm_roots(pmd, disk_super);
821
822 return dm_tm_commit(pmd->tm, sblock);
823}
824
825static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
826{
827 int r;
828 dm_block_t total;
829 dm_block_t max_blocks = 4096; /* 16M */
830
831 r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
832 if (r) {
833 DMERR("could not get size of metadata device");
834 pmd->metadata_reserve = max_blocks;
835 } else
836 pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
837}
838
839struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
840 sector_t data_block_size,
841 bool format_device)
842{
843 int r;
844 struct dm_pool_metadata *pmd;
845
846 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
847 if (!pmd) {
848 DMERR("could not allocate metadata struct");
849 return ERR_PTR(-ENOMEM);
850 }
851
852 init_rwsem(&pmd->root_lock);
853 pmd->time = 0;
854 INIT_LIST_HEAD(&pmd->thin_devices);
855 pmd->fail_io = false;
856 pmd->bdev = bdev;
857 pmd->data_block_size = data_block_size;
858
859 r = __create_persistent_data_objects(pmd, format_device);
860 if (r) {
861 kfree(pmd);
862 return ERR_PTR(r);
863 }
864
865 r = __begin_transaction(pmd);
866 if (r < 0) {
867 if (dm_pool_metadata_close(pmd) < 0)
868 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
869 return ERR_PTR(r);
870 }
871
872 __set_metadata_reserve(pmd);
873
874 return pmd;
875}
876
877int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
878{
879 int r;
880 unsigned open_devices = 0;
881 struct dm_thin_device *td, *tmp;
882
883 down_read(&pmd->root_lock);
884 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
885 if (td->open_count)
886 open_devices++;
887 else {
888 list_del(&td->list);
889 kfree(td);
890 }
891 }
892 up_read(&pmd->root_lock);
893
894 if (open_devices) {
895 DMERR("attempt to close pmd when %u device(s) are still open",
896 open_devices);
897 return -EBUSY;
898 }
899
900 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
901 r = __commit_transaction(pmd);
902 if (r < 0)
903 DMWARN("%s: __commit_transaction() failed, error = %d",
904 __func__, r);
905 }
906
907 if (!pmd->fail_io)
908 __destroy_persistent_data_objects(pmd);
909
910 kfree(pmd);
911 return 0;
912}
913
914/*
915 * __open_device: Returns @td corresponding to device with id @dev,
916 * creating it if @create is set and incrementing @td->open_count.
917 * On failure, @td is undefined.
918 */
919static int __open_device(struct dm_pool_metadata *pmd,
920 dm_thin_id dev, int create,
921 struct dm_thin_device **td)
922{
923 int r, changed = 0;
924 struct dm_thin_device *td2;
925 uint64_t key = dev;
926 struct disk_device_details details_le;
927
928 /*
929 * If the device is already open, return it.
930 */
931 list_for_each_entry(td2, &pmd->thin_devices, list)
932 if (td2->id == dev) {
933 /*
934 * May not create an already-open device.
935 */
936 if (create)
937 return -EEXIST;
938
939 td2->open_count++;
940 *td = td2;
941 return 0;
942 }
943
944 /*
945 * Check the device exists.
946 */
947 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
948 &key, &details_le);
949 if (r) {
950 if (r != -ENODATA || !create)
951 return r;
952
953 /*
954 * Create new device.
955 */
956 changed = 1;
957 details_le.mapped_blocks = 0;
958 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
959 details_le.creation_time = cpu_to_le32(pmd->time);
960 details_le.snapshotted_time = cpu_to_le32(pmd->time);
961 }
962
963 *td = kmalloc(sizeof(**td), GFP_NOIO);
964 if (!*td)
965 return -ENOMEM;
966
967 (*td)->pmd = pmd;
968 (*td)->id = dev;
969 (*td)->open_count = 1;
970 (*td)->changed = changed;
971 (*td)->aborted_with_changes = false;
972 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
973 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
974 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
975 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
976
977 list_add(&(*td)->list, &pmd->thin_devices);
978
979 return 0;
980}
981
982static void __close_device(struct dm_thin_device *td)
983{
984 --td->open_count;
985}
986
987static int __create_thin(struct dm_pool_metadata *pmd,
988 dm_thin_id dev)
989{
990 int r;
991 dm_block_t dev_root;
992 uint64_t key = dev;
993 struct disk_device_details details_le;
994 struct dm_thin_device *td;
995 __le64 value;
996
997 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
998 &key, &details_le);
999 if (!r)
1000 return -EEXIST;
1001
1002 /*
1003 * Create an empty btree for the mappings.
1004 */
1005 r = dm_btree_empty(&pmd->bl_info, &dev_root);
1006 if (r)
1007 return r;
1008
1009 /*
1010 * Insert it into the main mapping tree.
1011 */
1012 value = cpu_to_le64(dev_root);
1013 __dm_bless_for_disk(&value);
1014 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1015 if (r) {
1016 dm_btree_del(&pmd->bl_info, dev_root);
1017 return r;
1018 }
1019
1020 r = __open_device(pmd, dev, 1, &td);
1021 if (r) {
1022 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1023 dm_btree_del(&pmd->bl_info, dev_root);
1024 return r;
1025 }
1026 __close_device(td);
1027
1028 return r;
1029}
1030
1031int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1032{
1033 int r = -EINVAL;
1034
1035 down_write(&pmd->root_lock);
1036 if (!pmd->fail_io)
1037 r = __create_thin(pmd, dev);
1038 up_write(&pmd->root_lock);
1039
1040 return r;
1041}
1042
1043static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1044 struct dm_thin_device *snap,
1045 dm_thin_id origin, uint32_t time)
1046{
1047 int r;
1048 struct dm_thin_device *td;
1049
1050 r = __open_device(pmd, origin, 0, &td);
1051 if (r)
1052 return r;
1053
1054 td->changed = 1;
1055 td->snapshotted_time = time;
1056
1057 snap->mapped_blocks = td->mapped_blocks;
1058 snap->snapshotted_time = time;
1059 __close_device(td);
1060
1061 return 0;
1062}
1063
1064static int __create_snap(struct dm_pool_metadata *pmd,
1065 dm_thin_id dev, dm_thin_id origin)
1066{
1067 int r;
1068 dm_block_t origin_root;
1069 uint64_t key = origin, dev_key = dev;
1070 struct dm_thin_device *td;
1071 struct disk_device_details details_le;
1072 __le64 value;
1073
1074 /* check this device is unused */
1075 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1076 &dev_key, &details_le);
1077 if (!r)
1078 return -EEXIST;
1079
1080 /* find the mapping tree for the origin */
1081 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1082 if (r)
1083 return r;
1084 origin_root = le64_to_cpu(value);
1085
1086 /* clone the origin, an inc will do */
1087 dm_tm_inc(pmd->tm, origin_root);
1088
1089 /* insert into the main mapping tree */
1090 value = cpu_to_le64(origin_root);
1091 __dm_bless_for_disk(&value);
1092 key = dev;
1093 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1094 if (r) {
1095 dm_tm_dec(pmd->tm, origin_root);
1096 return r;
1097 }
1098
1099 pmd->time++;
1100
1101 r = __open_device(pmd, dev, 1, &td);
1102 if (r)
1103 goto bad;
1104
1105 r = __set_snapshot_details(pmd, td, origin, pmd->time);
1106 __close_device(td);
1107
1108 if (r)
1109 goto bad;
1110
1111 return 0;
1112
1113bad:
1114 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1115 dm_btree_remove(&pmd->details_info, pmd->details_root,
1116 &key, &pmd->details_root);
1117 return r;
1118}
1119
1120int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1121 dm_thin_id dev,
1122 dm_thin_id origin)
1123{
1124 int r = -EINVAL;
1125
1126 down_write(&pmd->root_lock);
1127 if (!pmd->fail_io)
1128 r = __create_snap(pmd, dev, origin);
1129 up_write(&pmd->root_lock);
1130
1131 return r;
1132}
1133
1134static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1135{
1136 int r;
1137 uint64_t key = dev;
1138 struct dm_thin_device *td;
1139
1140 /* TODO: failure should mark the transaction invalid */
1141 r = __open_device(pmd, dev, 0, &td);
1142 if (r)
1143 return r;
1144
1145 if (td->open_count > 1) {
1146 __close_device(td);
1147 return -EBUSY;
1148 }
1149
1150 list_del(&td->list);
1151 kfree(td);
1152 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1153 &key, &pmd->details_root);
1154 if (r)
1155 return r;
1156
1157 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1158 if (r)
1159 return r;
1160
1161 return 0;
1162}
1163
1164int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1165 dm_thin_id dev)
1166{
1167 int r = -EINVAL;
1168
1169 down_write(&pmd->root_lock);
1170 if (!pmd->fail_io)
1171 r = __delete_device(pmd, dev);
1172 up_write(&pmd->root_lock);
1173
1174 return r;
1175}
1176
1177int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1178 uint64_t current_id,
1179 uint64_t new_id)
1180{
1181 int r = -EINVAL;
1182
1183 down_write(&pmd->root_lock);
1184
1185 if (pmd->fail_io)
1186 goto out;
1187
1188 if (pmd->trans_id != current_id) {
1189 DMERR("mismatched transaction id");
1190 goto out;
1191 }
1192
1193 pmd->trans_id = new_id;
1194 r = 0;
1195
1196out:
1197 up_write(&pmd->root_lock);
1198
1199 return r;
1200}
1201
1202int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1203 uint64_t *result)
1204{
1205 int r = -EINVAL;
1206
1207 down_read(&pmd->root_lock);
1208 if (!pmd->fail_io) {
1209 *result = pmd->trans_id;
1210 r = 0;
1211 }
1212 up_read(&pmd->root_lock);
1213
1214 return r;
1215}
1216
1217static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1218{
1219 int r, inc;
1220 struct thin_disk_superblock *disk_super;
1221 struct dm_block *copy, *sblock;
1222 dm_block_t held_root;
1223
1224 /*
1225 * We commit to ensure the btree roots which we increment in a
1226 * moment are up to date.
1227 */
1228 __commit_transaction(pmd);
1229
1230 /*
1231 * Copy the superblock.
1232 */
1233 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1234 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1235 &sb_validator, &copy, &inc);
1236 if (r)
1237 return r;
1238
1239 BUG_ON(!inc);
1240
1241 held_root = dm_block_location(copy);
1242 disk_super = dm_block_data(copy);
1243
1244 if (le64_to_cpu(disk_super->held_root)) {
1245 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1246
1247 dm_tm_dec(pmd->tm, held_root);
1248 dm_tm_unlock(pmd->tm, copy);
1249 return -EBUSY;
1250 }
1251
1252 /*
1253 * Wipe the spacemap since we're not publishing this.
1254 */
1255 memset(&disk_super->data_space_map_root, 0,
1256 sizeof(disk_super->data_space_map_root));
1257 memset(&disk_super->metadata_space_map_root, 0,
1258 sizeof(disk_super->metadata_space_map_root));
1259
1260 /*
1261 * Increment the data structures that need to be preserved.
1262 */
1263 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1264 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1265 dm_tm_unlock(pmd->tm, copy);
1266
1267 /*
1268 * Write the held root into the superblock.
1269 */
1270 r = superblock_lock(pmd, &sblock);
1271 if (r) {
1272 dm_tm_dec(pmd->tm, held_root);
1273 return r;
1274 }
1275
1276 disk_super = dm_block_data(sblock);
1277 disk_super->held_root = cpu_to_le64(held_root);
1278 dm_bm_unlock(sblock);
1279 return 0;
1280}
1281
1282int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1283{
1284 int r = -EINVAL;
1285
1286 down_write(&pmd->root_lock);
1287 if (!pmd->fail_io)
1288 r = __reserve_metadata_snap(pmd);
1289 up_write(&pmd->root_lock);
1290
1291 return r;
1292}
1293
1294static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1295{
1296 int r;
1297 struct thin_disk_superblock *disk_super;
1298 struct dm_block *sblock, *copy;
1299 dm_block_t held_root;
1300
1301 r = superblock_lock(pmd, &sblock);
1302 if (r)
1303 return r;
1304
1305 disk_super = dm_block_data(sblock);
1306 held_root = le64_to_cpu(disk_super->held_root);
1307 disk_super->held_root = cpu_to_le64(0);
1308
1309 dm_bm_unlock(sblock);
1310
1311 if (!held_root) {
1312 DMWARN("No pool metadata snapshot found: nothing to release.");
1313 return -EINVAL;
1314 }
1315
1316 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
1317 if (r)
1318 return r;
1319
1320 disk_super = dm_block_data(copy);
1321 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
1322 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
1323 dm_sm_dec_block(pmd->metadata_sm, held_root);
1324
1325 dm_tm_unlock(pmd->tm, copy);
1326
1327 return 0;
1328}
1329
1330int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1331{
1332 int r = -EINVAL;
1333
1334 down_write(&pmd->root_lock);
1335 if (!pmd->fail_io)
1336 r = __release_metadata_snap(pmd);
1337 up_write(&pmd->root_lock);
1338
1339 return r;
1340}
1341
1342static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1343 dm_block_t *result)
1344{
1345 int r;
1346 struct thin_disk_superblock *disk_super;
1347 struct dm_block *sblock;
1348
1349 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1350 &sb_validator, &sblock);
1351 if (r)
1352 return r;
1353
1354 disk_super = dm_block_data(sblock);
1355 *result = le64_to_cpu(disk_super->held_root);
1356
1357 dm_bm_unlock(sblock);
1358
1359 return 0;
1360}
1361
1362int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1363 dm_block_t *result)
1364{
1365 int r = -EINVAL;
1366
1367 down_read(&pmd->root_lock);
1368 if (!pmd->fail_io)
1369 r = __get_metadata_snap(pmd, result);
1370 up_read(&pmd->root_lock);
1371
1372 return r;
1373}
1374
1375int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1376 struct dm_thin_device **td)
1377{
1378 int r = -EINVAL;
1379
1380 down_write(&pmd->root_lock);
1381 if (!pmd->fail_io)
1382 r = __open_device(pmd, dev, 0, td);
1383 up_write(&pmd->root_lock);
1384
1385 return r;
1386}
1387
1388int dm_pool_close_thin_device(struct dm_thin_device *td)
1389{
1390 down_write(&td->pmd->root_lock);
1391 __close_device(td);
1392 up_write(&td->pmd->root_lock);
1393
1394 return 0;
1395}
1396
1397dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1398{
1399 return td->id;
1400}
1401
1402/*
1403 * Check whether @time (of block creation) is older than @td's last snapshot.
1404 * If so then the associated block is shared with the last snapshot device.
1405 * Any block on a device created *after* the device last got snapshotted is
1406 * necessarily not shared.
1407 */
1408static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1409{
1410 return td->snapshotted_time > time;
1411}
1412
1413static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
1414 struct dm_thin_lookup_result *result)
1415{
1416 uint64_t block_time = 0;
1417 dm_block_t exception_block;
1418 uint32_t exception_time;
1419
1420 block_time = le64_to_cpu(value);
1421 unpack_block_time(block_time, &exception_block, &exception_time);
1422 result->block = exception_block;
1423 result->shared = __snapshotted_since(td, exception_time);
1424}
1425
1426static int __find_block(struct dm_thin_device *td, dm_block_t block,
1427 int can_issue_io, struct dm_thin_lookup_result *result)
1428{
1429 int r;
1430 __le64 value;
1431 struct dm_pool_metadata *pmd = td->pmd;
1432 dm_block_t keys[2] = { td->id, block };
1433 struct dm_btree_info *info;
1434
1435 if (can_issue_io) {
1436 info = &pmd->info;
1437 } else
1438 info = &pmd->nb_info;
1439
1440 r = dm_btree_lookup(info, pmd->root, keys, &value);
1441 if (!r)
1442 unpack_lookup_result(td, value, result);
1443
1444 return r;
1445}
1446
1447int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1448 int can_issue_io, struct dm_thin_lookup_result *result)
1449{
1450 int r;
1451 struct dm_pool_metadata *pmd = td->pmd;
1452
1453 down_read(&pmd->root_lock);
1454 if (pmd->fail_io) {
1455 up_read(&pmd->root_lock);
1456 return -EINVAL;
1457 }
1458
1459 r = __find_block(td, block, can_issue_io, result);
1460
1461 up_read(&pmd->root_lock);
1462 return r;
1463}
1464
1465static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
1466 dm_block_t *vblock,
1467 struct dm_thin_lookup_result *result)
1468{
1469 int r;
1470 __le64 value;
1471 struct dm_pool_metadata *pmd = td->pmd;
1472 dm_block_t keys[2] = { td->id, block };
1473
1474 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1475 if (!r)
1476 unpack_lookup_result(td, value, result);
1477
1478 return r;
1479}
1480
1481static int __find_mapped_range(struct dm_thin_device *td,
1482 dm_block_t begin, dm_block_t end,
1483 dm_block_t *thin_begin, dm_block_t *thin_end,
1484 dm_block_t *pool_begin, bool *maybe_shared)
1485{
1486 int r;
1487 dm_block_t pool_end;
1488 struct dm_thin_lookup_result lookup;
1489
1490 if (end < begin)
1491 return -ENODATA;
1492
1493 r = __find_next_mapped_block(td, begin, &begin, &lookup);
1494 if (r)
1495 return r;
1496
1497 if (begin >= end)
1498 return -ENODATA;
1499
1500 *thin_begin = begin;
1501 *pool_begin = lookup.block;
1502 *maybe_shared = lookup.shared;
1503
1504 begin++;
1505 pool_end = *pool_begin + 1;
1506 while (begin != end) {
1507 r = __find_block(td, begin, true, &lookup);
1508 if (r) {
1509 if (r == -ENODATA)
1510 break;
1511 else
1512 return r;
1513 }
1514
1515 if ((lookup.block != pool_end) ||
1516 (lookup.shared != *maybe_shared))
1517 break;
1518
1519 pool_end++;
1520 begin++;
1521 }
1522
1523 *thin_end = begin;
1524 return 0;
1525}
1526
1527int dm_thin_find_mapped_range(struct dm_thin_device *td,
1528 dm_block_t begin, dm_block_t end,
1529 dm_block_t *thin_begin, dm_block_t *thin_end,
1530 dm_block_t *pool_begin, bool *maybe_shared)
1531{
1532 int r = -EINVAL;
1533 struct dm_pool_metadata *pmd = td->pmd;
1534
1535 down_read(&pmd->root_lock);
1536 if (!pmd->fail_io) {
1537 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
1538 pool_begin, maybe_shared);
1539 }
1540 up_read(&pmd->root_lock);
1541
1542 return r;
1543}
1544
1545static int __insert(struct dm_thin_device *td, dm_block_t block,
1546 dm_block_t data_block)
1547{
1548 int r, inserted;
1549 __le64 value;
1550 struct dm_pool_metadata *pmd = td->pmd;
1551 dm_block_t keys[2] = { td->id, block };
1552
1553 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1554 __dm_bless_for_disk(&value);
1555
1556 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1557 &pmd->root, &inserted);
1558 if (r)
1559 return r;
1560
1561 td->changed = 1;
1562 if (inserted)
1563 td->mapped_blocks++;
1564
1565 return 0;
1566}
1567
1568int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1569 dm_block_t data_block)
1570{
1571 int r = -EINVAL;
1572
1573 down_write(&td->pmd->root_lock);
1574 if (!td->pmd->fail_io)
1575 r = __insert(td, block, data_block);
1576 up_write(&td->pmd->root_lock);
1577
1578 return r;
1579}
1580
1581static int __remove(struct dm_thin_device *td, dm_block_t block)
1582{
1583 int r;
1584 struct dm_pool_metadata *pmd = td->pmd;
1585 dm_block_t keys[2] = { td->id, block };
1586
1587 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1588 if (r)
1589 return r;
1590
1591 td->mapped_blocks--;
1592 td->changed = 1;
1593
1594 return 0;
1595}
1596
1597static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1598{
1599 int r;
1600 unsigned count, total_count = 0;
1601 struct dm_pool_metadata *pmd = td->pmd;
1602 dm_block_t keys[1] = { td->id };
1603 __le64 value;
1604 dm_block_t mapping_root;
1605
1606 /*
1607 * Find the mapping tree
1608 */
1609 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
1610 if (r)
1611 return r;
1612
1613 /*
1614 * Remove from the mapping tree, taking care to inc the
1615 * ref count so it doesn't get deleted.
1616 */
1617 mapping_root = le64_to_cpu(value);
1618 dm_tm_inc(pmd->tm, mapping_root);
1619 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
1620 if (r)
1621 return r;
1622
1623 /*
1624 * Remove leaves stops at the first unmapped entry, so we have to
1625 * loop round finding mapped ranges.
1626 */
1627 while (begin < end) {
1628 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
1629 if (r == -ENODATA)
1630 break;
1631
1632 if (r)
1633 return r;
1634
1635 if (begin >= end)
1636 break;
1637
1638 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
1639 if (r)
1640 return r;
1641
1642 total_count += count;
1643 }
1644
1645 td->mapped_blocks -= total_count;
1646 td->changed = 1;
1647
1648 /*
1649 * Reinsert the mapping tree.
1650 */
1651 value = cpu_to_le64(mapping_root);
1652 __dm_bless_for_disk(&value);
1653 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
1654}
1655
1656int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1657{
1658 int r = -EINVAL;
1659
1660 down_write(&td->pmd->root_lock);
1661 if (!td->pmd->fail_io)
1662 r = __remove(td, block);
1663 up_write(&td->pmd->root_lock);
1664
1665 return r;
1666}
1667
1668int dm_thin_remove_range(struct dm_thin_device *td,
1669 dm_block_t begin, dm_block_t end)
1670{
1671 int r = -EINVAL;
1672
1673 down_write(&td->pmd->root_lock);
1674 if (!td->pmd->fail_io)
1675 r = __remove_range(td, begin, end);
1676 up_write(&td->pmd->root_lock);
1677
1678 return r;
1679}
1680
1681int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
1682{
1683 int r;
1684 uint32_t ref_count;
1685
1686 down_read(&pmd->root_lock);
1687 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
1688 if (!r)
1689 *result = (ref_count > 1);
1690 up_read(&pmd->root_lock);
1691
1692 return r;
1693}
1694
1695int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1696{
1697 int r = 0;
1698
1699 down_write(&pmd->root_lock);
1700 for (; b != e; b++) {
1701 r = dm_sm_inc_block(pmd->data_sm, b);
1702 if (r)
1703 break;
1704 }
1705 up_write(&pmd->root_lock);
1706
1707 return r;
1708}
1709
1710int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1711{
1712 int r = 0;
1713
1714 down_write(&pmd->root_lock);
1715 for (; b != e; b++) {
1716 r = dm_sm_dec_block(pmd->data_sm, b);
1717 if (r)
1718 break;
1719 }
1720 up_write(&pmd->root_lock);
1721
1722 return r;
1723}
1724
1725bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1726{
1727 int r;
1728
1729 down_read(&td->pmd->root_lock);
1730 r = td->changed;
1731 up_read(&td->pmd->root_lock);
1732
1733 return r;
1734}
1735
1736bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
1737{
1738 bool r = false;
1739 struct dm_thin_device *td, *tmp;
1740
1741 down_read(&pmd->root_lock);
1742 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1743 if (td->changed) {
1744 r = td->changed;
1745 break;
1746 }
1747 }
1748 up_read(&pmd->root_lock);
1749
1750 return r;
1751}
1752
1753bool dm_thin_aborted_changes(struct dm_thin_device *td)
1754{
1755 bool r;
1756
1757 down_read(&td->pmd->root_lock);
1758 r = td->aborted_with_changes;
1759 up_read(&td->pmd->root_lock);
1760
1761 return r;
1762}
1763
1764int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1765{
1766 int r = -EINVAL;
1767
1768 down_write(&pmd->root_lock);
1769 if (!pmd->fail_io)
1770 r = dm_sm_new_block(pmd->data_sm, result);
1771 up_write(&pmd->root_lock);
1772
1773 return r;
1774}
1775
1776int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1777{
1778 int r = -EINVAL;
1779
1780 down_write(&pmd->root_lock);
1781 if (pmd->fail_io)
1782 goto out;
1783
1784 r = __commit_transaction(pmd);
1785 if (r <= 0)
1786 goto out;
1787
1788 /*
1789 * Open the next transaction.
1790 */
1791 r = __begin_transaction(pmd);
1792out:
1793 up_write(&pmd->root_lock);
1794 return r;
1795}
1796
1797static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1798{
1799 struct dm_thin_device *td;
1800
1801 list_for_each_entry(td, &pmd->thin_devices, list)
1802 td->aborted_with_changes = td->changed;
1803}
1804
1805int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1806{
1807 int r = -EINVAL;
1808
1809 down_write(&pmd->root_lock);
1810 if (pmd->fail_io)
1811 goto out;
1812
1813 __set_abort_with_changes_flags(pmd);
1814 __destroy_persistent_data_objects(pmd);
1815 r = __create_persistent_data_objects(pmd, false);
1816 if (r)
1817 pmd->fail_io = true;
1818
1819out:
1820 up_write(&pmd->root_lock);
1821
1822 return r;
1823}
1824
1825int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1826{
1827 int r = -EINVAL;
1828
1829 down_read(&pmd->root_lock);
1830 if (!pmd->fail_io)
1831 r = dm_sm_get_nr_free(pmd->data_sm, result);
1832 up_read(&pmd->root_lock);
1833
1834 return r;
1835}
1836
1837int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1838 dm_block_t *result)
1839{
1840 int r = -EINVAL;
1841
1842 down_read(&pmd->root_lock);
1843 if (!pmd->fail_io)
1844 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1845
1846 if (!r) {
1847 if (*result < pmd->metadata_reserve)
1848 *result = 0;
1849 else
1850 *result -= pmd->metadata_reserve;
1851 }
1852 up_read(&pmd->root_lock);
1853
1854 return r;
1855}
1856
1857int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1858 dm_block_t *result)
1859{
1860 int r = -EINVAL;
1861
1862 down_read(&pmd->root_lock);
1863 if (!pmd->fail_io)
1864 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1865 up_read(&pmd->root_lock);
1866
1867 return r;
1868}
1869
1870int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1871{
1872 int r = -EINVAL;
1873
1874 down_read(&pmd->root_lock);
1875 if (!pmd->fail_io)
1876 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1877 up_read(&pmd->root_lock);
1878
1879 return r;
1880}
1881
1882int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1883{
1884 int r = -EINVAL;
1885 struct dm_pool_metadata *pmd = td->pmd;
1886
1887 down_read(&pmd->root_lock);
1888 if (!pmd->fail_io) {
1889 *result = td->mapped_blocks;
1890 r = 0;
1891 }
1892 up_read(&pmd->root_lock);
1893
1894 return r;
1895}
1896
1897static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1898{
1899 int r;
1900 __le64 value_le;
1901 dm_block_t thin_root;
1902 struct dm_pool_metadata *pmd = td->pmd;
1903
1904 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1905 if (r)
1906 return r;
1907
1908 thin_root = le64_to_cpu(value_le);
1909
1910 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1911}
1912
1913int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1914 dm_block_t *result)
1915{
1916 int r = -EINVAL;
1917 struct dm_pool_metadata *pmd = td->pmd;
1918
1919 down_read(&pmd->root_lock);
1920 if (!pmd->fail_io)
1921 r = __highest_block(td, result);
1922 up_read(&pmd->root_lock);
1923
1924 return r;
1925}
1926
1927static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
1928{
1929 int r;
1930 dm_block_t old_count;
1931
1932 r = dm_sm_get_nr_blocks(sm, &old_count);
1933 if (r)
1934 return r;
1935
1936 if (new_count == old_count)
1937 return 0;
1938
1939 if (new_count < old_count) {
1940 DMERR("cannot reduce size of space map");
1941 return -EINVAL;
1942 }
1943
1944 return dm_sm_extend(sm, new_count - old_count);
1945}
1946
1947int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1948{
1949 int r = -EINVAL;
1950
1951 down_write(&pmd->root_lock);
1952 if (!pmd->fail_io)
1953 r = __resize_space_map(pmd->data_sm, new_count);
1954 up_write(&pmd->root_lock);
1955
1956 return r;
1957}
1958
1959int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1960{
1961 int r = -EINVAL;
1962
1963 down_write(&pmd->root_lock);
1964 if (!pmd->fail_io) {
1965 r = __resize_space_map(pmd->metadata_sm, new_count);
1966 if (!r)
1967 __set_metadata_reserve(pmd);
1968 }
1969 up_write(&pmd->root_lock);
1970
1971 return r;
1972}
1973
1974void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1975{
1976 down_write(&pmd->root_lock);
1977 dm_bm_set_read_only(pmd->bm);
1978 up_write(&pmd->root_lock);
1979}
1980
1981void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
1982{
1983 down_write(&pmd->root_lock);
1984 dm_bm_set_read_write(pmd->bm);
1985 up_write(&pmd->root_lock);
1986}
1987
1988int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
1989 dm_block_t threshold,
1990 dm_sm_threshold_fn fn,
1991 void *context)
1992{
1993 int r;
1994
1995 down_write(&pmd->root_lock);
1996 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
1997 up_write(&pmd->root_lock);
1998
1999 return r;
2000}
2001
2002int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
2003{
2004 int r;
2005 struct dm_block *sblock;
2006 struct thin_disk_superblock *disk_super;
2007
2008 down_write(&pmd->root_lock);
2009 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
2010
2011 r = superblock_lock(pmd, &sblock);
2012 if (r) {
2013 DMERR("couldn't read superblock");
2014 goto out;
2015 }
2016
2017 disk_super = dm_block_data(sblock);
2018 disk_super->flags = cpu_to_le32(pmd->flags);
2019
2020 dm_bm_unlock(sblock);
2021out:
2022 up_write(&pmd->root_lock);
2023 return r;
2024}
2025
2026bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
2027{
2028 bool needs_check;
2029
2030 down_read(&pmd->root_lock);
2031 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
2032 up_read(&pmd->root_lock);
2033
2034 return needs_check;
2035}
2036
2037void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
2038{
2039 down_read(&pmd->root_lock);
2040 if (!pmd->fail_io)
2041 dm_tm_issue_prefetches(pmd->tm);
2042 up_read(&pmd->root_lock);
2043}
2044