Loading...
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 40
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 * Pre-commit callback.
193 *
194 * This allows the thin provisioning target to run a callback before
195 * the metadata are committed.
196 */
197 dm_pool_pre_commit_fn pre_commit_fn;
198 void *pre_commit_context;
199
200 /*
201 * We reserve a section of the metadata for commit overhead.
202 * All reported space does *not* include this.
203 */
204 dm_block_t metadata_reserve;
205
206 /*
207 * Set if a transaction has to be aborted but the attempt to roll back
208 * to the previous (good) transaction failed. The only pool metadata
209 * operation possible in this state is the closing of the device.
210 */
211 bool fail_io:1;
212
213 /*
214 * Set once a thin-pool has been accessed through one of the interfaces
215 * that imply the pool is in-service (e.g. thin devices created/deleted,
216 * thin-pool message, metadata snapshots, etc).
217 */
218 bool in_service:1;
219
220 /*
221 * Reading the space map roots can fail, so we read it into these
222 * buffers before the superblock is locked and updated.
223 */
224 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
225 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
226};
227
228struct dm_thin_device {
229 struct list_head list;
230 struct dm_pool_metadata *pmd;
231 dm_thin_id id;
232
233 int open_count;
234 bool changed:1;
235 bool aborted_with_changes:1;
236 uint64_t mapped_blocks;
237 uint64_t transaction_id;
238 uint32_t creation_time;
239 uint32_t snapshotted_time;
240};
241
242/*----------------------------------------------------------------
243 * superblock validator
244 *--------------------------------------------------------------*/
245
246#define SUPERBLOCK_CSUM_XOR 160774
247
248static void sb_prepare_for_write(struct dm_block_validator *v,
249 struct dm_block *b,
250 size_t block_size)
251{
252 struct thin_disk_superblock *disk_super = dm_block_data(b);
253
254 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
255 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
256 block_size - sizeof(__le32),
257 SUPERBLOCK_CSUM_XOR));
258}
259
260static int sb_check(struct dm_block_validator *v,
261 struct dm_block *b,
262 size_t block_size)
263{
264 struct thin_disk_superblock *disk_super = dm_block_data(b);
265 __le32 csum_le;
266
267 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
268 DMERR("sb_check failed: blocknr %llu: "
269 "wanted %llu", le64_to_cpu(disk_super->blocknr),
270 (unsigned long long)dm_block_location(b));
271 return -ENOTBLK;
272 }
273
274 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
275 DMERR("sb_check failed: magic %llu: "
276 "wanted %llu", le64_to_cpu(disk_super->magic),
277 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
278 return -EILSEQ;
279 }
280
281 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
282 block_size - sizeof(__le32),
283 SUPERBLOCK_CSUM_XOR));
284 if (csum_le != disk_super->csum) {
285 DMERR("sb_check failed: csum %u: wanted %u",
286 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
287 return -EILSEQ;
288 }
289
290 return 0;
291}
292
293static struct dm_block_validator sb_validator = {
294 .name = "superblock",
295 .prepare_for_write = sb_prepare_for_write,
296 .check = sb_check
297};
298
299/*----------------------------------------------------------------
300 * Methods for the btree value types
301 *--------------------------------------------------------------*/
302
303static uint64_t pack_block_time(dm_block_t b, uint32_t t)
304{
305 return (b << 24) | t;
306}
307
308static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
309{
310 *b = v >> 24;
311 *t = v & ((1 << 24) - 1);
312}
313
314/*
315 * It's more efficient to call dm_sm_{inc,dec}_blocks as few times as
316 * possible. 'with_runs' reads contiguous runs of blocks, and calls the
317 * given sm function.
318 */
319typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t);
320
321static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned count, run_fn fn)
322{
323 uint64_t b, begin, end;
324 uint32_t t;
325 bool in_run = false;
326 unsigned i;
327
328 for (i = 0; i < count; i++, value_le++) {
329 /* We know value_le is 8 byte aligned */
330 unpack_block_time(le64_to_cpu(*value_le), &b, &t);
331
332 if (in_run) {
333 if (b == end) {
334 end++;
335 } else {
336 fn(sm, begin, end);
337 begin = b;
338 end = b + 1;
339 }
340 } else {
341 in_run = true;
342 begin = b;
343 end = b + 1;
344 }
345 }
346
347 if (in_run)
348 fn(sm, begin, end);
349}
350
351static void data_block_inc(void *context, const void *value_le, unsigned count)
352{
353 with_runs((struct dm_space_map *) context,
354 (const __le64 *) value_le, count, dm_sm_inc_blocks);
355}
356
357static void data_block_dec(void *context, const void *value_le, unsigned count)
358{
359 with_runs((struct dm_space_map *) context,
360 (const __le64 *) value_le, count, dm_sm_dec_blocks);
361}
362
363static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
364{
365 __le64 v1_le, v2_le;
366 uint64_t b1, b2;
367 uint32_t t;
368
369 memcpy(&v1_le, value1_le, sizeof(v1_le));
370 memcpy(&v2_le, value2_le, sizeof(v2_le));
371 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
372 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
373
374 return b1 == b2;
375}
376
377static void subtree_inc(void *context, const void *value, unsigned count)
378{
379 struct dm_btree_info *info = context;
380 const __le64 *root_le = value;
381 unsigned i;
382
383 for (i = 0; i < count; i++, root_le++)
384 dm_tm_inc(info->tm, le64_to_cpu(*root_le));
385}
386
387static void subtree_dec(void *context, const void *value, unsigned count)
388{
389 struct dm_btree_info *info = context;
390 const __le64 *root_le = value;
391 unsigned i;
392
393 for (i = 0; i < count; i++, root_le++)
394 if (dm_btree_del(info, le64_to_cpu(*root_le)))
395 DMERR("btree delete failed");
396}
397
398static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
399{
400 __le64 v1_le, v2_le;
401 memcpy(&v1_le, value1_le, sizeof(v1_le));
402 memcpy(&v2_le, value2_le, sizeof(v2_le));
403
404 return v1_le == v2_le;
405}
406
407/*----------------------------------------------------------------*/
408
409/*
410 * Variant that is used for in-core only changes or code that
411 * shouldn't put the pool in service on its own (e.g. commit).
412 */
413static inline void pmd_write_lock_in_core(struct dm_pool_metadata *pmd)
414 __acquires(pmd->root_lock)
415{
416 down_write(&pmd->root_lock);
417}
418
419static inline void pmd_write_lock(struct dm_pool_metadata *pmd)
420{
421 pmd_write_lock_in_core(pmd);
422 if (unlikely(!pmd->in_service))
423 pmd->in_service = true;
424}
425
426static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)
427 __releases(pmd->root_lock)
428{
429 up_write(&pmd->root_lock);
430}
431
432/*----------------------------------------------------------------*/
433
434static int superblock_lock_zero(struct dm_pool_metadata *pmd,
435 struct dm_block **sblock)
436{
437 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
438 &sb_validator, sblock);
439}
440
441static int superblock_lock(struct dm_pool_metadata *pmd,
442 struct dm_block **sblock)
443{
444 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
445 &sb_validator, sblock);
446}
447
448static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
449{
450 int r;
451 unsigned i;
452 struct dm_block *b;
453 __le64 *data_le, zero = cpu_to_le64(0);
454 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
455
456 /*
457 * We can't use a validator here - it may be all zeroes.
458 */
459 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
460 if (r)
461 return r;
462
463 data_le = dm_block_data(b);
464 *result = 1;
465 for (i = 0; i < block_size; i++) {
466 if (data_le[i] != zero) {
467 *result = 0;
468 break;
469 }
470 }
471
472 dm_bm_unlock(b);
473
474 return 0;
475}
476
477static void __setup_btree_details(struct dm_pool_metadata *pmd)
478{
479 pmd->info.tm = pmd->tm;
480 pmd->info.levels = 2;
481 pmd->info.value_type.context = pmd->data_sm;
482 pmd->info.value_type.size = sizeof(__le64);
483 pmd->info.value_type.inc = data_block_inc;
484 pmd->info.value_type.dec = data_block_dec;
485 pmd->info.value_type.equal = data_block_equal;
486
487 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
488 pmd->nb_info.tm = pmd->nb_tm;
489
490 pmd->tl_info.tm = pmd->tm;
491 pmd->tl_info.levels = 1;
492 pmd->tl_info.value_type.context = &pmd->bl_info;
493 pmd->tl_info.value_type.size = sizeof(__le64);
494 pmd->tl_info.value_type.inc = subtree_inc;
495 pmd->tl_info.value_type.dec = subtree_dec;
496 pmd->tl_info.value_type.equal = subtree_equal;
497
498 pmd->bl_info.tm = pmd->tm;
499 pmd->bl_info.levels = 1;
500 pmd->bl_info.value_type.context = pmd->data_sm;
501 pmd->bl_info.value_type.size = sizeof(__le64);
502 pmd->bl_info.value_type.inc = data_block_inc;
503 pmd->bl_info.value_type.dec = data_block_dec;
504 pmd->bl_info.value_type.equal = data_block_equal;
505
506 pmd->details_info.tm = pmd->tm;
507 pmd->details_info.levels = 1;
508 pmd->details_info.value_type.context = NULL;
509 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
510 pmd->details_info.value_type.inc = NULL;
511 pmd->details_info.value_type.dec = NULL;
512 pmd->details_info.value_type.equal = NULL;
513}
514
515static int save_sm_roots(struct dm_pool_metadata *pmd)
516{
517 int r;
518 size_t len;
519
520 r = dm_sm_root_size(pmd->metadata_sm, &len);
521 if (r < 0)
522 return r;
523
524 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
525 if (r < 0)
526 return r;
527
528 r = dm_sm_root_size(pmd->data_sm, &len);
529 if (r < 0)
530 return r;
531
532 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
533}
534
535static void copy_sm_roots(struct dm_pool_metadata *pmd,
536 struct thin_disk_superblock *disk)
537{
538 memcpy(&disk->metadata_space_map_root,
539 &pmd->metadata_space_map_root,
540 sizeof(pmd->metadata_space_map_root));
541
542 memcpy(&disk->data_space_map_root,
543 &pmd->data_space_map_root,
544 sizeof(pmd->data_space_map_root));
545}
546
547static int __write_initial_superblock(struct dm_pool_metadata *pmd)
548{
549 int r;
550 struct dm_block *sblock;
551 struct thin_disk_superblock *disk_super;
552 sector_t bdev_size = bdev_nr_sectors(pmd->bdev);
553
554 if (bdev_size > THIN_METADATA_MAX_SECTORS)
555 bdev_size = THIN_METADATA_MAX_SECTORS;
556
557 r = dm_sm_commit(pmd->data_sm);
558 if (r < 0)
559 return r;
560
561 r = dm_tm_pre_commit(pmd->tm);
562 if (r < 0)
563 return r;
564
565 r = save_sm_roots(pmd);
566 if (r < 0)
567 return r;
568
569 r = superblock_lock_zero(pmd, &sblock);
570 if (r)
571 return r;
572
573 disk_super = dm_block_data(sblock);
574 disk_super->flags = 0;
575 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
576 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
577 disk_super->version = cpu_to_le32(THIN_VERSION);
578 disk_super->time = 0;
579 disk_super->trans_id = 0;
580 disk_super->held_root = 0;
581
582 copy_sm_roots(pmd, disk_super);
583
584 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
585 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
586 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
587 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
588 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
589
590 return dm_tm_commit(pmd->tm, sblock);
591}
592
593static int __format_metadata(struct dm_pool_metadata *pmd)
594{
595 int r;
596
597 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
598 &pmd->tm, &pmd->metadata_sm);
599 if (r < 0) {
600 DMERR("tm_create_with_sm failed");
601 return r;
602 }
603
604 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
605 if (IS_ERR(pmd->data_sm)) {
606 DMERR("sm_disk_create failed");
607 r = PTR_ERR(pmd->data_sm);
608 goto bad_cleanup_tm;
609 }
610
611 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
612 if (!pmd->nb_tm) {
613 DMERR("could not create non-blocking clone tm");
614 r = -ENOMEM;
615 goto bad_cleanup_data_sm;
616 }
617
618 __setup_btree_details(pmd);
619
620 r = dm_btree_empty(&pmd->info, &pmd->root);
621 if (r < 0)
622 goto bad_cleanup_nb_tm;
623
624 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
625 if (r < 0) {
626 DMERR("couldn't create devices root");
627 goto bad_cleanup_nb_tm;
628 }
629
630 r = __write_initial_superblock(pmd);
631 if (r)
632 goto bad_cleanup_nb_tm;
633
634 return 0;
635
636bad_cleanup_nb_tm:
637 dm_tm_destroy(pmd->nb_tm);
638bad_cleanup_data_sm:
639 dm_sm_destroy(pmd->data_sm);
640bad_cleanup_tm:
641 dm_tm_destroy(pmd->tm);
642 dm_sm_destroy(pmd->metadata_sm);
643
644 return r;
645}
646
647static int __check_incompat_features(struct thin_disk_superblock *disk_super,
648 struct dm_pool_metadata *pmd)
649{
650 uint32_t features;
651
652 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
653 if (features) {
654 DMERR("could not access metadata due to unsupported optional features (%lx).",
655 (unsigned long)features);
656 return -EINVAL;
657 }
658
659 /*
660 * Check for read-only metadata to skip the following RDWR checks.
661 */
662 if (bdev_read_only(pmd->bdev))
663 return 0;
664
665 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
666 if (features) {
667 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
668 (unsigned long)features);
669 return -EINVAL;
670 }
671
672 return 0;
673}
674
675static int __open_metadata(struct dm_pool_metadata *pmd)
676{
677 int r;
678 struct dm_block *sblock;
679 struct thin_disk_superblock *disk_super;
680
681 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
682 &sb_validator, &sblock);
683 if (r < 0) {
684 DMERR("couldn't read superblock");
685 return r;
686 }
687
688 disk_super = dm_block_data(sblock);
689
690 /* Verify the data block size hasn't changed */
691 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
692 DMERR("changing the data block size (from %u to %llu) is not supported",
693 le32_to_cpu(disk_super->data_block_size),
694 (unsigned long long)pmd->data_block_size);
695 r = -EINVAL;
696 goto bad_unlock_sblock;
697 }
698
699 r = __check_incompat_features(disk_super, pmd);
700 if (r < 0)
701 goto bad_unlock_sblock;
702
703 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
704 disk_super->metadata_space_map_root,
705 sizeof(disk_super->metadata_space_map_root),
706 &pmd->tm, &pmd->metadata_sm);
707 if (r < 0) {
708 DMERR("tm_open_with_sm failed");
709 goto bad_unlock_sblock;
710 }
711
712 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
713 sizeof(disk_super->data_space_map_root));
714 if (IS_ERR(pmd->data_sm)) {
715 DMERR("sm_disk_open failed");
716 r = PTR_ERR(pmd->data_sm);
717 goto bad_cleanup_tm;
718 }
719
720 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
721 if (!pmd->nb_tm) {
722 DMERR("could not create non-blocking clone tm");
723 r = -ENOMEM;
724 goto bad_cleanup_data_sm;
725 }
726
727 /*
728 * For pool metadata opening process, root setting is redundant
729 * because it will be set again in __begin_transaction(). But dm
730 * pool aborting process really needs to get last transaction's
731 * root to avoid accessing broken btree.
732 */
733 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
734 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
735
736 __setup_btree_details(pmd);
737 dm_bm_unlock(sblock);
738
739 return 0;
740
741bad_cleanup_data_sm:
742 dm_sm_destroy(pmd->data_sm);
743bad_cleanup_tm:
744 dm_tm_destroy(pmd->tm);
745 dm_sm_destroy(pmd->metadata_sm);
746bad_unlock_sblock:
747 dm_bm_unlock(sblock);
748
749 return r;
750}
751
752static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
753{
754 int r, unformatted;
755
756 r = __superblock_all_zeroes(pmd->bm, &unformatted);
757 if (r)
758 return r;
759
760 if (unformatted)
761 return format_device ? __format_metadata(pmd) : -EPERM;
762
763 return __open_metadata(pmd);
764}
765
766static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
767{
768 int r;
769
770 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
771 THIN_MAX_CONCURRENT_LOCKS);
772 if (IS_ERR(pmd->bm)) {
773 DMERR("could not create block manager");
774 r = PTR_ERR(pmd->bm);
775 pmd->bm = NULL;
776 return r;
777 }
778
779 r = __open_or_format_metadata(pmd, format_device);
780 if (r) {
781 dm_block_manager_destroy(pmd->bm);
782 pmd->bm = NULL;
783 }
784
785 return r;
786}
787
788static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd,
789 bool destroy_bm)
790{
791 dm_sm_destroy(pmd->data_sm);
792 dm_sm_destroy(pmd->metadata_sm);
793 dm_tm_destroy(pmd->nb_tm);
794 dm_tm_destroy(pmd->tm);
795 if (destroy_bm)
796 dm_block_manager_destroy(pmd->bm);
797}
798
799static int __begin_transaction(struct dm_pool_metadata *pmd)
800{
801 int r;
802 struct thin_disk_superblock *disk_super;
803 struct dm_block *sblock;
804
805 /*
806 * We re-read the superblock every time. Shouldn't need to do this
807 * really.
808 */
809 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
810 &sb_validator, &sblock);
811 if (r)
812 return r;
813
814 disk_super = dm_block_data(sblock);
815 pmd->time = le32_to_cpu(disk_super->time);
816 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
817 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
818 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
819 pmd->flags = le32_to_cpu(disk_super->flags);
820 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
821
822 dm_bm_unlock(sblock);
823 return 0;
824}
825
826static int __write_changed_details(struct dm_pool_metadata *pmd)
827{
828 int r;
829 struct dm_thin_device *td, *tmp;
830 struct disk_device_details details;
831 uint64_t key;
832
833 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
834 if (!td->changed)
835 continue;
836
837 key = td->id;
838
839 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
840 details.transaction_id = cpu_to_le64(td->transaction_id);
841 details.creation_time = cpu_to_le32(td->creation_time);
842 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
843 __dm_bless_for_disk(&details);
844
845 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
846 &key, &details, &pmd->details_root);
847 if (r)
848 return r;
849
850 if (td->open_count)
851 td->changed = false;
852 else {
853 list_del(&td->list);
854 kfree(td);
855 }
856 }
857
858 return 0;
859}
860
861static int __commit_transaction(struct dm_pool_metadata *pmd)
862{
863 int r;
864 struct thin_disk_superblock *disk_super;
865 struct dm_block *sblock;
866
867 /*
868 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
869 */
870 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
871 BUG_ON(!rwsem_is_locked(&pmd->root_lock));
872
873 if (unlikely(!pmd->in_service))
874 return 0;
875
876 if (pmd->pre_commit_fn) {
877 r = pmd->pre_commit_fn(pmd->pre_commit_context);
878 if (r < 0) {
879 DMERR("pre-commit callback failed");
880 return r;
881 }
882 }
883
884 r = __write_changed_details(pmd);
885 if (r < 0)
886 return r;
887
888 r = dm_sm_commit(pmd->data_sm);
889 if (r < 0)
890 return r;
891
892 r = dm_tm_pre_commit(pmd->tm);
893 if (r < 0)
894 return r;
895
896 r = save_sm_roots(pmd);
897 if (r < 0)
898 return r;
899
900 r = superblock_lock(pmd, &sblock);
901 if (r)
902 return r;
903
904 disk_super = dm_block_data(sblock);
905 disk_super->time = cpu_to_le32(pmd->time);
906 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
907 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
908 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
909 disk_super->flags = cpu_to_le32(pmd->flags);
910
911 copy_sm_roots(pmd, disk_super);
912
913 return dm_tm_commit(pmd->tm, sblock);
914}
915
916static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
917{
918 int r;
919 dm_block_t total;
920 dm_block_t max_blocks = 4096; /* 16M */
921
922 r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
923 if (r) {
924 DMERR("could not get size of metadata device");
925 pmd->metadata_reserve = max_blocks;
926 } else
927 pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
928}
929
930struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
931 sector_t data_block_size,
932 bool format_device)
933{
934 int r;
935 struct dm_pool_metadata *pmd;
936
937 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
938 if (!pmd) {
939 DMERR("could not allocate metadata struct");
940 return ERR_PTR(-ENOMEM);
941 }
942
943 init_rwsem(&pmd->root_lock);
944 pmd->time = 0;
945 INIT_LIST_HEAD(&pmd->thin_devices);
946 pmd->fail_io = false;
947 pmd->in_service = false;
948 pmd->bdev = bdev;
949 pmd->data_block_size = data_block_size;
950 pmd->pre_commit_fn = NULL;
951 pmd->pre_commit_context = NULL;
952
953 r = __create_persistent_data_objects(pmd, format_device);
954 if (r) {
955 kfree(pmd);
956 return ERR_PTR(r);
957 }
958
959 r = __begin_transaction(pmd);
960 if (r < 0) {
961 if (dm_pool_metadata_close(pmd) < 0)
962 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
963 return ERR_PTR(r);
964 }
965
966 __set_metadata_reserve(pmd);
967
968 return pmd;
969}
970
971int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
972{
973 int r;
974 unsigned open_devices = 0;
975 struct dm_thin_device *td, *tmp;
976
977 down_read(&pmd->root_lock);
978 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
979 if (td->open_count)
980 open_devices++;
981 else {
982 list_del(&td->list);
983 kfree(td);
984 }
985 }
986 up_read(&pmd->root_lock);
987
988 if (open_devices) {
989 DMERR("attempt to close pmd when %u device(s) are still open",
990 open_devices);
991 return -EBUSY;
992 }
993
994 pmd_write_lock_in_core(pmd);
995 if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) {
996 r = __commit_transaction(pmd);
997 if (r < 0)
998 DMWARN("%s: __commit_transaction() failed, error = %d",
999 __func__, r);
1000 }
1001 pmd_write_unlock(pmd);
1002 if (!pmd->fail_io)
1003 __destroy_persistent_data_objects(pmd, true);
1004
1005 kfree(pmd);
1006 return 0;
1007}
1008
1009/*
1010 * __open_device: Returns @td corresponding to device with id @dev,
1011 * creating it if @create is set and incrementing @td->open_count.
1012 * On failure, @td is undefined.
1013 */
1014static int __open_device(struct dm_pool_metadata *pmd,
1015 dm_thin_id dev, int create,
1016 struct dm_thin_device **td)
1017{
1018 int r, changed = 0;
1019 struct dm_thin_device *td2;
1020 uint64_t key = dev;
1021 struct disk_device_details details_le;
1022
1023 /*
1024 * If the device is already open, return it.
1025 */
1026 list_for_each_entry(td2, &pmd->thin_devices, list)
1027 if (td2->id == dev) {
1028 /*
1029 * May not create an already-open device.
1030 */
1031 if (create)
1032 return -EEXIST;
1033
1034 td2->open_count++;
1035 *td = td2;
1036 return 0;
1037 }
1038
1039 /*
1040 * Check the device exists.
1041 */
1042 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1043 &key, &details_le);
1044 if (r) {
1045 if (r != -ENODATA || !create)
1046 return r;
1047
1048 /*
1049 * Create new device.
1050 */
1051 changed = 1;
1052 details_le.mapped_blocks = 0;
1053 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
1054 details_le.creation_time = cpu_to_le32(pmd->time);
1055 details_le.snapshotted_time = cpu_to_le32(pmd->time);
1056 }
1057
1058 *td = kmalloc(sizeof(**td), GFP_NOIO);
1059 if (!*td)
1060 return -ENOMEM;
1061
1062 (*td)->pmd = pmd;
1063 (*td)->id = dev;
1064 (*td)->open_count = 1;
1065 (*td)->changed = changed;
1066 (*td)->aborted_with_changes = false;
1067 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
1068 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
1069 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
1070 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
1071
1072 list_add(&(*td)->list, &pmd->thin_devices);
1073
1074 return 0;
1075}
1076
1077static void __close_device(struct dm_thin_device *td)
1078{
1079 --td->open_count;
1080}
1081
1082static int __create_thin(struct dm_pool_metadata *pmd,
1083 dm_thin_id dev)
1084{
1085 int r;
1086 dm_block_t dev_root;
1087 uint64_t key = dev;
1088 struct dm_thin_device *td;
1089 __le64 value;
1090
1091 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1092 &key, NULL);
1093 if (!r)
1094 return -EEXIST;
1095
1096 /*
1097 * Create an empty btree for the mappings.
1098 */
1099 r = dm_btree_empty(&pmd->bl_info, &dev_root);
1100 if (r)
1101 return r;
1102
1103 /*
1104 * Insert it into the main mapping tree.
1105 */
1106 value = cpu_to_le64(dev_root);
1107 __dm_bless_for_disk(&value);
1108 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1109 if (r) {
1110 dm_btree_del(&pmd->bl_info, dev_root);
1111 return r;
1112 }
1113
1114 r = __open_device(pmd, dev, 1, &td);
1115 if (r) {
1116 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1117 dm_btree_del(&pmd->bl_info, dev_root);
1118 return r;
1119 }
1120 __close_device(td);
1121
1122 return r;
1123}
1124
1125int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1126{
1127 int r = -EINVAL;
1128
1129 pmd_write_lock(pmd);
1130 if (!pmd->fail_io)
1131 r = __create_thin(pmd, dev);
1132 pmd_write_unlock(pmd);
1133
1134 return r;
1135}
1136
1137static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1138 struct dm_thin_device *snap,
1139 dm_thin_id origin, uint32_t time)
1140{
1141 int r;
1142 struct dm_thin_device *td;
1143
1144 r = __open_device(pmd, origin, 0, &td);
1145 if (r)
1146 return r;
1147
1148 td->changed = true;
1149 td->snapshotted_time = time;
1150
1151 snap->mapped_blocks = td->mapped_blocks;
1152 snap->snapshotted_time = time;
1153 __close_device(td);
1154
1155 return 0;
1156}
1157
1158static int __create_snap(struct dm_pool_metadata *pmd,
1159 dm_thin_id dev, dm_thin_id origin)
1160{
1161 int r;
1162 dm_block_t origin_root;
1163 uint64_t key = origin, dev_key = dev;
1164 struct dm_thin_device *td;
1165 __le64 value;
1166
1167 /* check this device is unused */
1168 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1169 &dev_key, NULL);
1170 if (!r)
1171 return -EEXIST;
1172
1173 /* find the mapping tree for the origin */
1174 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1175 if (r)
1176 return r;
1177 origin_root = le64_to_cpu(value);
1178
1179 /* clone the origin, an inc will do */
1180 dm_tm_inc(pmd->tm, origin_root);
1181
1182 /* insert into the main mapping tree */
1183 value = cpu_to_le64(origin_root);
1184 __dm_bless_for_disk(&value);
1185 key = dev;
1186 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1187 if (r) {
1188 dm_tm_dec(pmd->tm, origin_root);
1189 return r;
1190 }
1191
1192 pmd->time++;
1193
1194 r = __open_device(pmd, dev, 1, &td);
1195 if (r)
1196 goto bad;
1197
1198 r = __set_snapshot_details(pmd, td, origin, pmd->time);
1199 __close_device(td);
1200
1201 if (r)
1202 goto bad;
1203
1204 return 0;
1205
1206bad:
1207 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1208 dm_btree_remove(&pmd->details_info, pmd->details_root,
1209 &key, &pmd->details_root);
1210 return r;
1211}
1212
1213int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1214 dm_thin_id dev,
1215 dm_thin_id origin)
1216{
1217 int r = -EINVAL;
1218
1219 pmd_write_lock(pmd);
1220 if (!pmd->fail_io)
1221 r = __create_snap(pmd, dev, origin);
1222 pmd_write_unlock(pmd);
1223
1224 return r;
1225}
1226
1227static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1228{
1229 int r;
1230 uint64_t key = dev;
1231 struct dm_thin_device *td;
1232
1233 /* TODO: failure should mark the transaction invalid */
1234 r = __open_device(pmd, dev, 0, &td);
1235 if (r)
1236 return r;
1237
1238 if (td->open_count > 1) {
1239 __close_device(td);
1240 return -EBUSY;
1241 }
1242
1243 list_del(&td->list);
1244 kfree(td);
1245 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1246 &key, &pmd->details_root);
1247 if (r)
1248 return r;
1249
1250 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1251 if (r)
1252 return r;
1253
1254 return 0;
1255}
1256
1257int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1258 dm_thin_id dev)
1259{
1260 int r = -EINVAL;
1261
1262 pmd_write_lock(pmd);
1263 if (!pmd->fail_io)
1264 r = __delete_device(pmd, dev);
1265 pmd_write_unlock(pmd);
1266
1267 return r;
1268}
1269
1270int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1271 uint64_t current_id,
1272 uint64_t new_id)
1273{
1274 int r = -EINVAL;
1275
1276 pmd_write_lock(pmd);
1277
1278 if (pmd->fail_io)
1279 goto out;
1280
1281 if (pmd->trans_id != current_id) {
1282 DMERR("mismatched transaction id");
1283 goto out;
1284 }
1285
1286 pmd->trans_id = new_id;
1287 r = 0;
1288
1289out:
1290 pmd_write_unlock(pmd);
1291
1292 return r;
1293}
1294
1295int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1296 uint64_t *result)
1297{
1298 int r = -EINVAL;
1299
1300 down_read(&pmd->root_lock);
1301 if (!pmd->fail_io) {
1302 *result = pmd->trans_id;
1303 r = 0;
1304 }
1305 up_read(&pmd->root_lock);
1306
1307 return r;
1308}
1309
1310static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1311{
1312 int r, inc;
1313 struct thin_disk_superblock *disk_super;
1314 struct dm_block *copy, *sblock;
1315 dm_block_t held_root;
1316
1317 /*
1318 * We commit to ensure the btree roots which we increment in a
1319 * moment are up to date.
1320 */
1321 r = __commit_transaction(pmd);
1322 if (r < 0) {
1323 DMWARN("%s: __commit_transaction() failed, error = %d",
1324 __func__, r);
1325 return r;
1326 }
1327
1328 /*
1329 * Copy the superblock.
1330 */
1331 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1332 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1333 &sb_validator, ©, &inc);
1334 if (r)
1335 return r;
1336
1337 BUG_ON(!inc);
1338
1339 held_root = dm_block_location(copy);
1340 disk_super = dm_block_data(copy);
1341
1342 if (le64_to_cpu(disk_super->held_root)) {
1343 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1344
1345 dm_tm_dec(pmd->tm, held_root);
1346 dm_tm_unlock(pmd->tm, copy);
1347 return -EBUSY;
1348 }
1349
1350 /*
1351 * Wipe the spacemap since we're not publishing this.
1352 */
1353 memset(&disk_super->data_space_map_root, 0,
1354 sizeof(disk_super->data_space_map_root));
1355 memset(&disk_super->metadata_space_map_root, 0,
1356 sizeof(disk_super->metadata_space_map_root));
1357
1358 /*
1359 * Increment the data structures that need to be preserved.
1360 */
1361 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1362 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1363 dm_tm_unlock(pmd->tm, copy);
1364
1365 /*
1366 * Write the held root into the superblock.
1367 */
1368 r = superblock_lock(pmd, &sblock);
1369 if (r) {
1370 dm_tm_dec(pmd->tm, held_root);
1371 return r;
1372 }
1373
1374 disk_super = dm_block_data(sblock);
1375 disk_super->held_root = cpu_to_le64(held_root);
1376 dm_bm_unlock(sblock);
1377 return 0;
1378}
1379
1380int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1381{
1382 int r = -EINVAL;
1383
1384 pmd_write_lock(pmd);
1385 if (!pmd->fail_io)
1386 r = __reserve_metadata_snap(pmd);
1387 pmd_write_unlock(pmd);
1388
1389 return r;
1390}
1391
1392static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1393{
1394 int r;
1395 struct thin_disk_superblock *disk_super;
1396 struct dm_block *sblock, *copy;
1397 dm_block_t held_root;
1398
1399 r = superblock_lock(pmd, &sblock);
1400 if (r)
1401 return r;
1402
1403 disk_super = dm_block_data(sblock);
1404 held_root = le64_to_cpu(disk_super->held_root);
1405 disk_super->held_root = cpu_to_le64(0);
1406
1407 dm_bm_unlock(sblock);
1408
1409 if (!held_root) {
1410 DMWARN("No pool metadata snapshot found: nothing to release.");
1411 return -EINVAL;
1412 }
1413
1414 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©);
1415 if (r)
1416 return r;
1417
1418 disk_super = dm_block_data(copy);
1419 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
1420 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
1421 dm_sm_dec_block(pmd->metadata_sm, held_root);
1422
1423 dm_tm_unlock(pmd->tm, copy);
1424
1425 return 0;
1426}
1427
1428int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1429{
1430 int r = -EINVAL;
1431
1432 pmd_write_lock(pmd);
1433 if (!pmd->fail_io)
1434 r = __release_metadata_snap(pmd);
1435 pmd_write_unlock(pmd);
1436
1437 return r;
1438}
1439
1440static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1441 dm_block_t *result)
1442{
1443 int r;
1444 struct thin_disk_superblock *disk_super;
1445 struct dm_block *sblock;
1446
1447 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1448 &sb_validator, &sblock);
1449 if (r)
1450 return r;
1451
1452 disk_super = dm_block_data(sblock);
1453 *result = le64_to_cpu(disk_super->held_root);
1454
1455 dm_bm_unlock(sblock);
1456
1457 return 0;
1458}
1459
1460int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1461 dm_block_t *result)
1462{
1463 int r = -EINVAL;
1464
1465 down_read(&pmd->root_lock);
1466 if (!pmd->fail_io)
1467 r = __get_metadata_snap(pmd, result);
1468 up_read(&pmd->root_lock);
1469
1470 return r;
1471}
1472
1473int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1474 struct dm_thin_device **td)
1475{
1476 int r = -EINVAL;
1477
1478 pmd_write_lock_in_core(pmd);
1479 if (!pmd->fail_io)
1480 r = __open_device(pmd, dev, 0, td);
1481 pmd_write_unlock(pmd);
1482
1483 return r;
1484}
1485
1486int dm_pool_close_thin_device(struct dm_thin_device *td)
1487{
1488 pmd_write_lock_in_core(td->pmd);
1489 __close_device(td);
1490 pmd_write_unlock(td->pmd);
1491
1492 return 0;
1493}
1494
1495dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1496{
1497 return td->id;
1498}
1499
1500/*
1501 * Check whether @time (of block creation) is older than @td's last snapshot.
1502 * If so then the associated block is shared with the last snapshot device.
1503 * Any block on a device created *after* the device last got snapshotted is
1504 * necessarily not shared.
1505 */
1506static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1507{
1508 return td->snapshotted_time > time;
1509}
1510
1511static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
1512 struct dm_thin_lookup_result *result)
1513{
1514 uint64_t block_time = 0;
1515 dm_block_t exception_block;
1516 uint32_t exception_time;
1517
1518 block_time = le64_to_cpu(value);
1519 unpack_block_time(block_time, &exception_block, &exception_time);
1520 result->block = exception_block;
1521 result->shared = __snapshotted_since(td, exception_time);
1522}
1523
1524static int __find_block(struct dm_thin_device *td, dm_block_t block,
1525 int can_issue_io, struct dm_thin_lookup_result *result)
1526{
1527 int r;
1528 __le64 value;
1529 struct dm_pool_metadata *pmd = td->pmd;
1530 dm_block_t keys[2] = { td->id, block };
1531 struct dm_btree_info *info;
1532
1533 if (can_issue_io) {
1534 info = &pmd->info;
1535 } else
1536 info = &pmd->nb_info;
1537
1538 r = dm_btree_lookup(info, pmd->root, keys, &value);
1539 if (!r)
1540 unpack_lookup_result(td, value, result);
1541
1542 return r;
1543}
1544
1545int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1546 int can_issue_io, struct dm_thin_lookup_result *result)
1547{
1548 int r;
1549 struct dm_pool_metadata *pmd = td->pmd;
1550
1551 down_read(&pmd->root_lock);
1552 if (pmd->fail_io) {
1553 up_read(&pmd->root_lock);
1554 return -EINVAL;
1555 }
1556
1557 r = __find_block(td, block, can_issue_io, result);
1558
1559 up_read(&pmd->root_lock);
1560 return r;
1561}
1562
1563static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
1564 dm_block_t *vblock,
1565 struct dm_thin_lookup_result *result)
1566{
1567 int r;
1568 __le64 value;
1569 struct dm_pool_metadata *pmd = td->pmd;
1570 dm_block_t keys[2] = { td->id, block };
1571
1572 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1573 if (!r)
1574 unpack_lookup_result(td, value, result);
1575
1576 return r;
1577}
1578
1579static int __find_mapped_range(struct dm_thin_device *td,
1580 dm_block_t begin, dm_block_t end,
1581 dm_block_t *thin_begin, dm_block_t *thin_end,
1582 dm_block_t *pool_begin, bool *maybe_shared)
1583{
1584 int r;
1585 dm_block_t pool_end;
1586 struct dm_thin_lookup_result lookup;
1587
1588 if (end < begin)
1589 return -ENODATA;
1590
1591 r = __find_next_mapped_block(td, begin, &begin, &lookup);
1592 if (r)
1593 return r;
1594
1595 if (begin >= end)
1596 return -ENODATA;
1597
1598 *thin_begin = begin;
1599 *pool_begin = lookup.block;
1600 *maybe_shared = lookup.shared;
1601
1602 begin++;
1603 pool_end = *pool_begin + 1;
1604 while (begin != end) {
1605 r = __find_block(td, begin, true, &lookup);
1606 if (r) {
1607 if (r == -ENODATA)
1608 break;
1609 else
1610 return r;
1611 }
1612
1613 if ((lookup.block != pool_end) ||
1614 (lookup.shared != *maybe_shared))
1615 break;
1616
1617 pool_end++;
1618 begin++;
1619 }
1620
1621 *thin_end = begin;
1622 return 0;
1623}
1624
1625int dm_thin_find_mapped_range(struct dm_thin_device *td,
1626 dm_block_t begin, dm_block_t end,
1627 dm_block_t *thin_begin, dm_block_t *thin_end,
1628 dm_block_t *pool_begin, bool *maybe_shared)
1629{
1630 int r = -EINVAL;
1631 struct dm_pool_metadata *pmd = td->pmd;
1632
1633 down_read(&pmd->root_lock);
1634 if (!pmd->fail_io) {
1635 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
1636 pool_begin, maybe_shared);
1637 }
1638 up_read(&pmd->root_lock);
1639
1640 return r;
1641}
1642
1643static int __insert(struct dm_thin_device *td, dm_block_t block,
1644 dm_block_t data_block)
1645{
1646 int r, inserted;
1647 __le64 value;
1648 struct dm_pool_metadata *pmd = td->pmd;
1649 dm_block_t keys[2] = { td->id, block };
1650
1651 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1652 __dm_bless_for_disk(&value);
1653
1654 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1655 &pmd->root, &inserted);
1656 if (r)
1657 return r;
1658
1659 td->changed = true;
1660 if (inserted)
1661 td->mapped_blocks++;
1662
1663 return 0;
1664}
1665
1666int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1667 dm_block_t data_block)
1668{
1669 int r = -EINVAL;
1670
1671 pmd_write_lock(td->pmd);
1672 if (!td->pmd->fail_io)
1673 r = __insert(td, block, data_block);
1674 pmd_write_unlock(td->pmd);
1675
1676 return r;
1677}
1678
1679static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1680{
1681 int r;
1682 unsigned count, total_count = 0;
1683 struct dm_pool_metadata *pmd = td->pmd;
1684 dm_block_t keys[1] = { td->id };
1685 __le64 value;
1686 dm_block_t mapping_root;
1687
1688 /*
1689 * Find the mapping tree
1690 */
1691 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
1692 if (r)
1693 return r;
1694
1695 /*
1696 * Remove from the mapping tree, taking care to inc the
1697 * ref count so it doesn't get deleted.
1698 */
1699 mapping_root = le64_to_cpu(value);
1700 dm_tm_inc(pmd->tm, mapping_root);
1701 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
1702 if (r)
1703 return r;
1704
1705 /*
1706 * Remove leaves stops at the first unmapped entry, so we have to
1707 * loop round finding mapped ranges.
1708 */
1709 while (begin < end) {
1710 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
1711 if (r == -ENODATA)
1712 break;
1713
1714 if (r)
1715 return r;
1716
1717 if (begin >= end)
1718 break;
1719
1720 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
1721 if (r)
1722 return r;
1723
1724 total_count += count;
1725 }
1726
1727 td->mapped_blocks -= total_count;
1728 td->changed = true;
1729
1730 /*
1731 * Reinsert the mapping tree.
1732 */
1733 value = cpu_to_le64(mapping_root);
1734 __dm_bless_for_disk(&value);
1735 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
1736}
1737
1738int dm_thin_remove_range(struct dm_thin_device *td,
1739 dm_block_t begin, dm_block_t end)
1740{
1741 int r = -EINVAL;
1742
1743 pmd_write_lock(td->pmd);
1744 if (!td->pmd->fail_io)
1745 r = __remove_range(td, begin, end);
1746 pmd_write_unlock(td->pmd);
1747
1748 return r;
1749}
1750
1751int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
1752{
1753 int r;
1754 uint32_t ref_count;
1755
1756 down_read(&pmd->root_lock);
1757 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
1758 if (!r)
1759 *result = (ref_count > 1);
1760 up_read(&pmd->root_lock);
1761
1762 return r;
1763}
1764
1765int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1766{
1767 int r = 0;
1768
1769 pmd_write_lock(pmd);
1770 r = dm_sm_inc_blocks(pmd->data_sm, b, e);
1771 pmd_write_unlock(pmd);
1772
1773 return r;
1774}
1775
1776int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1777{
1778 int r = 0;
1779
1780 pmd_write_lock(pmd);
1781 r = dm_sm_dec_blocks(pmd->data_sm, b, e);
1782 pmd_write_unlock(pmd);
1783
1784 return r;
1785}
1786
1787bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1788{
1789 int r;
1790
1791 down_read(&td->pmd->root_lock);
1792 r = td->changed;
1793 up_read(&td->pmd->root_lock);
1794
1795 return r;
1796}
1797
1798bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
1799{
1800 bool r = false;
1801 struct dm_thin_device *td, *tmp;
1802
1803 down_read(&pmd->root_lock);
1804 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1805 if (td->changed) {
1806 r = td->changed;
1807 break;
1808 }
1809 }
1810 up_read(&pmd->root_lock);
1811
1812 return r;
1813}
1814
1815bool dm_thin_aborted_changes(struct dm_thin_device *td)
1816{
1817 bool r;
1818
1819 down_read(&td->pmd->root_lock);
1820 r = td->aborted_with_changes;
1821 up_read(&td->pmd->root_lock);
1822
1823 return r;
1824}
1825
1826int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1827{
1828 int r = -EINVAL;
1829
1830 pmd_write_lock(pmd);
1831 if (!pmd->fail_io)
1832 r = dm_sm_new_block(pmd->data_sm, result);
1833 pmd_write_unlock(pmd);
1834
1835 return r;
1836}
1837
1838int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1839{
1840 int r = -EINVAL;
1841
1842 /*
1843 * Care is taken to not have commit be what
1844 * triggers putting the thin-pool in-service.
1845 */
1846 pmd_write_lock_in_core(pmd);
1847 if (pmd->fail_io)
1848 goto out;
1849
1850 r = __commit_transaction(pmd);
1851 if (r < 0)
1852 goto out;
1853
1854 /*
1855 * Open the next transaction.
1856 */
1857 r = __begin_transaction(pmd);
1858out:
1859 pmd_write_unlock(pmd);
1860 return r;
1861}
1862
1863static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1864{
1865 struct dm_thin_device *td;
1866
1867 list_for_each_entry(td, &pmd->thin_devices, list)
1868 td->aborted_with_changes = td->changed;
1869}
1870
1871int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1872{
1873 int r = -EINVAL;
1874 struct dm_block_manager *old_bm = NULL, *new_bm = NULL;
1875
1876 /* fail_io is double-checked with pmd->root_lock held below */
1877 if (unlikely(pmd->fail_io))
1878 return r;
1879
1880 /*
1881 * Replacement block manager (new_bm) is created and old_bm destroyed outside of
1882 * pmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of
1883 * shrinker associated with the block manager's bufio client vs pmd root_lock).
1884 * - must take shrinker_rwsem without holding pmd->root_lock
1885 */
1886 new_bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
1887 THIN_MAX_CONCURRENT_LOCKS);
1888
1889 pmd_write_lock(pmd);
1890 if (pmd->fail_io) {
1891 pmd_write_unlock(pmd);
1892 goto out;
1893 }
1894
1895 __set_abort_with_changes_flags(pmd);
1896 __destroy_persistent_data_objects(pmd, false);
1897 old_bm = pmd->bm;
1898 if (IS_ERR(new_bm)) {
1899 DMERR("could not create block manager during abort");
1900 pmd->bm = NULL;
1901 r = PTR_ERR(new_bm);
1902 goto out_unlock;
1903 }
1904
1905 pmd->bm = new_bm;
1906 r = __open_or_format_metadata(pmd, false);
1907 if (r) {
1908 pmd->bm = NULL;
1909 goto out_unlock;
1910 }
1911 new_bm = NULL;
1912out_unlock:
1913 if (r)
1914 pmd->fail_io = true;
1915 pmd_write_unlock(pmd);
1916 dm_block_manager_destroy(old_bm);
1917out:
1918 if (new_bm && !IS_ERR(new_bm))
1919 dm_block_manager_destroy(new_bm);
1920
1921 return r;
1922}
1923
1924int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1925{
1926 int r = -EINVAL;
1927
1928 down_read(&pmd->root_lock);
1929 if (!pmd->fail_io)
1930 r = dm_sm_get_nr_free(pmd->data_sm, result);
1931 up_read(&pmd->root_lock);
1932
1933 return r;
1934}
1935
1936int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1937 dm_block_t *result)
1938{
1939 int r = -EINVAL;
1940
1941 down_read(&pmd->root_lock);
1942 if (!pmd->fail_io)
1943 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1944
1945 if (!r) {
1946 if (*result < pmd->metadata_reserve)
1947 *result = 0;
1948 else
1949 *result -= pmd->metadata_reserve;
1950 }
1951 up_read(&pmd->root_lock);
1952
1953 return r;
1954}
1955
1956int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1957 dm_block_t *result)
1958{
1959 int r = -EINVAL;
1960
1961 down_read(&pmd->root_lock);
1962 if (!pmd->fail_io)
1963 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1964 up_read(&pmd->root_lock);
1965
1966 return r;
1967}
1968
1969int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1970{
1971 int r = -EINVAL;
1972
1973 down_read(&pmd->root_lock);
1974 if (!pmd->fail_io)
1975 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1976 up_read(&pmd->root_lock);
1977
1978 return r;
1979}
1980
1981int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1982{
1983 int r = -EINVAL;
1984 struct dm_pool_metadata *pmd = td->pmd;
1985
1986 down_read(&pmd->root_lock);
1987 if (!pmd->fail_io) {
1988 *result = td->mapped_blocks;
1989 r = 0;
1990 }
1991 up_read(&pmd->root_lock);
1992
1993 return r;
1994}
1995
1996static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1997{
1998 int r;
1999 __le64 value_le;
2000 dm_block_t thin_root;
2001 struct dm_pool_metadata *pmd = td->pmd;
2002
2003 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
2004 if (r)
2005 return r;
2006
2007 thin_root = le64_to_cpu(value_le);
2008
2009 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
2010}
2011
2012int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
2013 dm_block_t *result)
2014{
2015 int r = -EINVAL;
2016 struct dm_pool_metadata *pmd = td->pmd;
2017
2018 down_read(&pmd->root_lock);
2019 if (!pmd->fail_io)
2020 r = __highest_block(td, result);
2021 up_read(&pmd->root_lock);
2022
2023 return r;
2024}
2025
2026static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
2027{
2028 int r;
2029 dm_block_t old_count;
2030
2031 r = dm_sm_get_nr_blocks(sm, &old_count);
2032 if (r)
2033 return r;
2034
2035 if (new_count == old_count)
2036 return 0;
2037
2038 if (new_count < old_count) {
2039 DMERR("cannot reduce size of space map");
2040 return -EINVAL;
2041 }
2042
2043 return dm_sm_extend(sm, new_count - old_count);
2044}
2045
2046int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
2047{
2048 int r = -EINVAL;
2049
2050 pmd_write_lock(pmd);
2051 if (!pmd->fail_io)
2052 r = __resize_space_map(pmd->data_sm, new_count);
2053 pmd_write_unlock(pmd);
2054
2055 return r;
2056}
2057
2058int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
2059{
2060 int r = -EINVAL;
2061
2062 pmd_write_lock(pmd);
2063 if (!pmd->fail_io) {
2064 r = __resize_space_map(pmd->metadata_sm, new_count);
2065 if (!r)
2066 __set_metadata_reserve(pmd);
2067 }
2068 pmd_write_unlock(pmd);
2069
2070 return r;
2071}
2072
2073void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
2074{
2075 pmd_write_lock_in_core(pmd);
2076 dm_bm_set_read_only(pmd->bm);
2077 pmd_write_unlock(pmd);
2078}
2079
2080void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
2081{
2082 pmd_write_lock_in_core(pmd);
2083 dm_bm_set_read_write(pmd->bm);
2084 pmd_write_unlock(pmd);
2085}
2086
2087int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
2088 dm_block_t threshold,
2089 dm_sm_threshold_fn fn,
2090 void *context)
2091{
2092 int r = -EINVAL;
2093
2094 pmd_write_lock_in_core(pmd);
2095 if (!pmd->fail_io) {
2096 r = dm_sm_register_threshold_callback(pmd->metadata_sm,
2097 threshold, fn, context);
2098 }
2099 pmd_write_unlock(pmd);
2100
2101 return r;
2102}
2103
2104void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
2105 dm_pool_pre_commit_fn fn,
2106 void *context)
2107{
2108 pmd_write_lock_in_core(pmd);
2109 pmd->pre_commit_fn = fn;
2110 pmd->pre_commit_context = context;
2111 pmd_write_unlock(pmd);
2112}
2113
2114int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
2115{
2116 int r = -EINVAL;
2117 struct dm_block *sblock;
2118 struct thin_disk_superblock *disk_super;
2119
2120 pmd_write_lock(pmd);
2121 if (pmd->fail_io)
2122 goto out;
2123
2124 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
2125
2126 r = superblock_lock(pmd, &sblock);
2127 if (r) {
2128 DMERR("couldn't lock superblock");
2129 goto out;
2130 }
2131
2132 disk_super = dm_block_data(sblock);
2133 disk_super->flags = cpu_to_le32(pmd->flags);
2134
2135 dm_bm_unlock(sblock);
2136out:
2137 pmd_write_unlock(pmd);
2138 return r;
2139}
2140
2141bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
2142{
2143 bool needs_check;
2144
2145 down_read(&pmd->root_lock);
2146 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
2147 up_read(&pmd->root_lock);
2148
2149 return needs_check;
2150}
2151
2152void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
2153{
2154 down_read(&pmd->root_lock);
2155 if (!pmd->fail_io)
2156 dm_tm_issue_prefetches(pmd->tm);
2157 up_read(&pmd->root_lock);
2158}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011-2012 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-thin-metadata.h"
9#include "persistent-data/dm-btree.h"
10#include "persistent-data/dm-space-map.h"
11#include "persistent-data/dm-space-map-disk.h"
12#include "persistent-data/dm-transaction-manager.h"
13
14#include <linux/list.h>
15#include <linux/device-mapper.h>
16#include <linux/workqueue.h>
17
18/*
19 *--------------------------------------------------------------------------
20 * As far as the metadata goes, there is:
21 *
22 * - A superblock in block zero, taking up fewer than 512 bytes for
23 * atomic writes.
24 *
25 * - A space map managing the metadata blocks.
26 *
27 * - A space map managing the data blocks.
28 *
29 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
30 *
31 * - A hierarchical btree, with 2 levels which effectively maps (thin
32 * dev id, virtual block) -> block_time. Block time is a 64-bit
33 * field holding the time in the low 24 bits, and block in the top 40
34 * bits.
35 *
36 * BTrees consist solely of btree_nodes, that fill a block. Some are
37 * internal nodes, as such their values are a __le64 pointing to other
38 * nodes. Leaf nodes can store data of any reasonable size (ie. much
39 * smaller than the block size). The nodes consist of the header,
40 * followed by an array of keys, followed by an array of values. We have
41 * to binary search on the keys so they're all held together to help the
42 * cpu cache.
43 *
44 * Space maps have 2 btrees:
45 *
46 * - One maps a uint64_t onto a struct index_entry. Which points to a
47 * bitmap block, and has some details about how many free entries there
48 * are etc.
49 *
50 * - The bitmap blocks have a header (for the checksum). Then the rest
51 * of the block is pairs of bits. With the meaning being:
52 *
53 * 0 - ref count is 0
54 * 1 - ref count is 1
55 * 2 - ref count is 2
56 * 3 - ref count is higher than 2
57 *
58 * - If the count is higher than 2 then the ref count is entered in a
59 * second btree that directly maps the block_address to a uint32_t ref
60 * count.
61 *
62 * The space map metadata variant doesn't have a bitmaps btree. Instead
63 * it has one single blocks worth of index_entries. This avoids
64 * recursive issues with the bitmap btree needing to allocate space in
65 * order to insert. With a small data block size such as 64k the
66 * metadata support data devices that are hundreds of terrabytes.
67 *
68 * The space maps allocate space linearly from front to back. Space that
69 * is freed in a transaction is never recycled within that transaction.
70 * To try and avoid fragmenting _free_ space the allocator always goes
71 * back and fills in gaps.
72 *
73 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
74 * from the block manager.
75 *--------------------------------------------------------------------------
76 */
77
78#define DM_MSG_PREFIX "thin metadata"
79
80#define THIN_SUPERBLOCK_MAGIC 27022010
81#define THIN_SUPERBLOCK_LOCATION 0
82#define THIN_VERSION 2
83#define SECTOR_TO_BLOCK_SHIFT 3
84
85/*
86 * For btree insert:
87 * 3 for btree insert +
88 * 2 for btree lookup used within space map
89 * For btree remove:
90 * 2 for shadow spine +
91 * 4 for rebalance 3 child node
92 */
93#define THIN_MAX_CONCURRENT_LOCKS 6
94
95/* This should be plenty */
96#define SPACE_MAP_ROOT_SIZE 128
97
98/*
99 * Little endian on-disk superblock and device details.
100 */
101struct thin_disk_superblock {
102 __le32 csum; /* Checksum of superblock except for this field. */
103 __le32 flags;
104 __le64 blocknr; /* This block number, dm_block_t. */
105
106 __u8 uuid[16];
107 __le64 magic;
108 __le32 version;
109 __le32 time;
110
111 __le64 trans_id;
112
113 /*
114 * Root held by userspace transactions.
115 */
116 __le64 held_root;
117
118 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
119 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
120
121 /*
122 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
123 */
124 __le64 data_mapping_root;
125
126 /*
127 * Device detail root mapping dev_id -> device_details
128 */
129 __le64 device_details_root;
130
131 __le32 data_block_size; /* In 512-byte sectors. */
132
133 __le32 metadata_block_size; /* In 512-byte sectors. */
134 __le64 metadata_nr_blocks;
135
136 __le32 compat_flags;
137 __le32 compat_ro_flags;
138 __le32 incompat_flags;
139} __packed;
140
141struct disk_device_details {
142 __le64 mapped_blocks;
143 __le64 transaction_id; /* When created. */
144 __le32 creation_time;
145 __le32 snapshotted_time;
146} __packed;
147
148struct dm_pool_metadata {
149 struct hlist_node hash;
150
151 struct block_device *bdev;
152 struct dm_block_manager *bm;
153 struct dm_space_map *metadata_sm;
154 struct dm_space_map *data_sm;
155 struct dm_transaction_manager *tm;
156 struct dm_transaction_manager *nb_tm;
157
158 /*
159 * Two-level btree.
160 * First level holds thin_dev_t.
161 * Second level holds mappings.
162 */
163 struct dm_btree_info info;
164
165 /*
166 * Non-blocking version of the above.
167 */
168 struct dm_btree_info nb_info;
169
170 /*
171 * Just the top level for deleting whole devices.
172 */
173 struct dm_btree_info tl_info;
174
175 /*
176 * Just the bottom level for creating new devices.
177 */
178 struct dm_btree_info bl_info;
179
180 /*
181 * Describes the device details btree.
182 */
183 struct dm_btree_info details_info;
184
185 struct rw_semaphore root_lock;
186 uint32_t time;
187 dm_block_t root;
188 dm_block_t details_root;
189 struct list_head thin_devices;
190 uint64_t trans_id;
191 unsigned long flags;
192 sector_t data_block_size;
193
194 /*
195 * Pre-commit callback.
196 *
197 * This allows the thin provisioning target to run a callback before
198 * the metadata are committed.
199 */
200 dm_pool_pre_commit_fn pre_commit_fn;
201 void *pre_commit_context;
202
203 /*
204 * We reserve a section of the metadata for commit overhead.
205 * All reported space does *not* include this.
206 */
207 dm_block_t metadata_reserve;
208
209 /*
210 * Set if a transaction has to be aborted but the attempt to roll back
211 * to the previous (good) transaction failed. The only pool metadata
212 * operation possible in this state is the closing of the device.
213 */
214 bool fail_io:1;
215
216 /*
217 * Set once a thin-pool has been accessed through one of the interfaces
218 * that imply the pool is in-service (e.g. thin devices created/deleted,
219 * thin-pool message, metadata snapshots, etc).
220 */
221 bool in_service:1;
222
223 /*
224 * Reading the space map roots can fail, so we read it into these
225 * buffers before the superblock is locked and updated.
226 */
227 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
228 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
229};
230
231struct dm_thin_device {
232 struct list_head list;
233 struct dm_pool_metadata *pmd;
234 dm_thin_id id;
235
236 int open_count;
237 bool changed:1;
238 bool aborted_with_changes:1;
239 uint64_t mapped_blocks;
240 uint64_t transaction_id;
241 uint32_t creation_time;
242 uint32_t snapshotted_time;
243};
244
245/*
246 *--------------------------------------------------------------
247 * superblock validator
248 *--------------------------------------------------------------
249 */
250#define SUPERBLOCK_CSUM_XOR 160774
251
252static void sb_prepare_for_write(const struct dm_block_validator *v,
253 struct dm_block *b,
254 size_t block_size)
255{
256 struct thin_disk_superblock *disk_super = dm_block_data(b);
257
258 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
259 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
260 block_size - sizeof(__le32),
261 SUPERBLOCK_CSUM_XOR));
262}
263
264static int sb_check(const struct dm_block_validator *v,
265 struct dm_block *b,
266 size_t block_size)
267{
268 struct thin_disk_superblock *disk_super = dm_block_data(b);
269 __le32 csum_le;
270
271 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
272 DMERR("%s failed: blocknr %llu: wanted %llu",
273 __func__, le64_to_cpu(disk_super->blocknr),
274 (unsigned long long)dm_block_location(b));
275 return -ENOTBLK;
276 }
277
278 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
279 DMERR("%s failed: magic %llu: wanted %llu",
280 __func__, le64_to_cpu(disk_super->magic),
281 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
282 return -EILSEQ;
283 }
284
285 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
286 block_size - sizeof(__le32),
287 SUPERBLOCK_CSUM_XOR));
288 if (csum_le != disk_super->csum) {
289 DMERR("%s failed: csum %u: wanted %u",
290 __func__, le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
291 return -EILSEQ;
292 }
293
294 return 0;
295}
296
297static const struct dm_block_validator sb_validator = {
298 .name = "superblock",
299 .prepare_for_write = sb_prepare_for_write,
300 .check = sb_check
301};
302
303/*
304 *--------------------------------------------------------------
305 * Methods for the btree value types
306 *--------------------------------------------------------------
307 */
308static uint64_t pack_block_time(dm_block_t b, uint32_t t)
309{
310 return (b << 24) | t;
311}
312
313static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
314{
315 *b = v >> 24;
316 *t = v & ((1 << 24) - 1);
317}
318
319/*
320 * It's more efficient to call dm_sm_{inc,dec}_blocks as few times as
321 * possible. 'with_runs' reads contiguous runs of blocks, and calls the
322 * given sm function.
323 */
324typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t);
325
326static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned int count, run_fn fn)
327{
328 uint64_t b, begin, end;
329 uint32_t t;
330 bool in_run = false;
331 unsigned int i;
332
333 for (i = 0; i < count; i++, value_le++) {
334 /* We know value_le is 8 byte aligned */
335 unpack_block_time(le64_to_cpu(*value_le), &b, &t);
336
337 if (in_run) {
338 if (b == end) {
339 end++;
340 } else {
341 fn(sm, begin, end);
342 begin = b;
343 end = b + 1;
344 }
345 } else {
346 in_run = true;
347 begin = b;
348 end = b + 1;
349 }
350 }
351
352 if (in_run)
353 fn(sm, begin, end);
354}
355
356static void data_block_inc(void *context, const void *value_le, unsigned int count)
357{
358 with_runs((struct dm_space_map *) context,
359 (const __le64 *) value_le, count, dm_sm_inc_blocks);
360}
361
362static void data_block_dec(void *context, const void *value_le, unsigned int count)
363{
364 with_runs((struct dm_space_map *) context,
365 (const __le64 *) value_le, count, dm_sm_dec_blocks);
366}
367
368static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
369{
370 __le64 v1_le, v2_le;
371 uint64_t b1, b2;
372 uint32_t t;
373
374 memcpy(&v1_le, value1_le, sizeof(v1_le));
375 memcpy(&v2_le, value2_le, sizeof(v2_le));
376 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
377 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
378
379 return b1 == b2;
380}
381
382static void subtree_inc(void *context, const void *value, unsigned int count)
383{
384 struct dm_btree_info *info = context;
385 const __le64 *root_le = value;
386 unsigned int i;
387
388 for (i = 0; i < count; i++, root_le++)
389 dm_tm_inc(info->tm, le64_to_cpu(*root_le));
390}
391
392static void subtree_dec(void *context, const void *value, unsigned int count)
393{
394 struct dm_btree_info *info = context;
395 const __le64 *root_le = value;
396 unsigned int i;
397
398 for (i = 0; i < count; i++, root_le++)
399 if (dm_btree_del(info, le64_to_cpu(*root_le)))
400 DMERR("btree delete failed");
401}
402
403static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
404{
405 __le64 v1_le, v2_le;
406
407 memcpy(&v1_le, value1_le, sizeof(v1_le));
408 memcpy(&v2_le, value2_le, sizeof(v2_le));
409
410 return v1_le == v2_le;
411}
412
413/*----------------------------------------------------------------*/
414
415/*
416 * Variant that is used for in-core only changes or code that
417 * shouldn't put the pool in service on its own (e.g. commit).
418 */
419static inline void pmd_write_lock_in_core(struct dm_pool_metadata *pmd)
420 __acquires(pmd->root_lock)
421{
422 down_write(&pmd->root_lock);
423}
424
425static inline void pmd_write_lock(struct dm_pool_metadata *pmd)
426{
427 pmd_write_lock_in_core(pmd);
428 if (unlikely(!pmd->in_service))
429 pmd->in_service = true;
430}
431
432static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)
433 __releases(pmd->root_lock)
434{
435 up_write(&pmd->root_lock);
436}
437
438/*----------------------------------------------------------------*/
439
440static int superblock_lock_zero(struct dm_pool_metadata *pmd,
441 struct dm_block **sblock)
442{
443 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
444 &sb_validator, sblock);
445}
446
447static int superblock_lock(struct dm_pool_metadata *pmd,
448 struct dm_block **sblock)
449{
450 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
451 &sb_validator, sblock);
452}
453
454static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
455{
456 int r;
457 unsigned int i;
458 struct dm_block *b;
459 __le64 *data_le, zero = cpu_to_le64(0);
460 unsigned int block_size = dm_bm_block_size(bm) / sizeof(__le64);
461
462 /*
463 * We can't use a validator here - it may be all zeroes.
464 */
465 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
466 if (r)
467 return r;
468
469 data_le = dm_block_data(b);
470 *result = 1;
471 for (i = 0; i < block_size; i++) {
472 if (data_le[i] != zero) {
473 *result = 0;
474 break;
475 }
476 }
477
478 dm_bm_unlock(b);
479
480 return 0;
481}
482
483static void __setup_btree_details(struct dm_pool_metadata *pmd)
484{
485 pmd->info.tm = pmd->tm;
486 pmd->info.levels = 2;
487 pmd->info.value_type.context = pmd->data_sm;
488 pmd->info.value_type.size = sizeof(__le64);
489 pmd->info.value_type.inc = data_block_inc;
490 pmd->info.value_type.dec = data_block_dec;
491 pmd->info.value_type.equal = data_block_equal;
492
493 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
494 pmd->nb_info.tm = pmd->nb_tm;
495
496 pmd->tl_info.tm = pmd->tm;
497 pmd->tl_info.levels = 1;
498 pmd->tl_info.value_type.context = &pmd->bl_info;
499 pmd->tl_info.value_type.size = sizeof(__le64);
500 pmd->tl_info.value_type.inc = subtree_inc;
501 pmd->tl_info.value_type.dec = subtree_dec;
502 pmd->tl_info.value_type.equal = subtree_equal;
503
504 pmd->bl_info.tm = pmd->tm;
505 pmd->bl_info.levels = 1;
506 pmd->bl_info.value_type.context = pmd->data_sm;
507 pmd->bl_info.value_type.size = sizeof(__le64);
508 pmd->bl_info.value_type.inc = data_block_inc;
509 pmd->bl_info.value_type.dec = data_block_dec;
510 pmd->bl_info.value_type.equal = data_block_equal;
511
512 pmd->details_info.tm = pmd->tm;
513 pmd->details_info.levels = 1;
514 pmd->details_info.value_type.context = NULL;
515 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
516 pmd->details_info.value_type.inc = NULL;
517 pmd->details_info.value_type.dec = NULL;
518 pmd->details_info.value_type.equal = NULL;
519}
520
521static int save_sm_roots(struct dm_pool_metadata *pmd)
522{
523 int r;
524 size_t len;
525
526 r = dm_sm_root_size(pmd->metadata_sm, &len);
527 if (r < 0)
528 return r;
529
530 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
531 if (r < 0)
532 return r;
533
534 r = dm_sm_root_size(pmd->data_sm, &len);
535 if (r < 0)
536 return r;
537
538 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
539}
540
541static void copy_sm_roots(struct dm_pool_metadata *pmd,
542 struct thin_disk_superblock *disk)
543{
544 memcpy(&disk->metadata_space_map_root,
545 &pmd->metadata_space_map_root,
546 sizeof(pmd->metadata_space_map_root));
547
548 memcpy(&disk->data_space_map_root,
549 &pmd->data_space_map_root,
550 sizeof(pmd->data_space_map_root));
551}
552
553static int __write_initial_superblock(struct dm_pool_metadata *pmd)
554{
555 int r;
556 struct dm_block *sblock;
557 struct thin_disk_superblock *disk_super;
558 sector_t bdev_size = bdev_nr_sectors(pmd->bdev);
559
560 if (bdev_size > THIN_METADATA_MAX_SECTORS)
561 bdev_size = THIN_METADATA_MAX_SECTORS;
562
563 r = dm_sm_commit(pmd->data_sm);
564 if (r < 0)
565 return r;
566
567 r = dm_tm_pre_commit(pmd->tm);
568 if (r < 0)
569 return r;
570
571 r = save_sm_roots(pmd);
572 if (r < 0)
573 return r;
574
575 r = superblock_lock_zero(pmd, &sblock);
576 if (r)
577 return r;
578
579 disk_super = dm_block_data(sblock);
580 disk_super->flags = 0;
581 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
582 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
583 disk_super->version = cpu_to_le32(THIN_VERSION);
584 disk_super->time = 0;
585 disk_super->trans_id = 0;
586 disk_super->held_root = 0;
587
588 copy_sm_roots(pmd, disk_super);
589
590 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
591 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
592 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
593 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
594 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
595
596 return dm_tm_commit(pmd->tm, sblock);
597}
598
599static int __format_metadata(struct dm_pool_metadata *pmd)
600{
601 int r;
602
603 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
604 &pmd->tm, &pmd->metadata_sm);
605 if (r < 0) {
606 pmd->tm = NULL;
607 pmd->metadata_sm = NULL;
608 DMERR("tm_create_with_sm failed");
609 return r;
610 }
611
612 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
613 if (IS_ERR(pmd->data_sm)) {
614 DMERR("sm_disk_create failed");
615 r = PTR_ERR(pmd->data_sm);
616 pmd->data_sm = NULL;
617 goto bad_cleanup_tm;
618 }
619
620 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
621 if (!pmd->nb_tm) {
622 DMERR("could not create non-blocking clone tm");
623 r = -ENOMEM;
624 goto bad_cleanup_data_sm;
625 }
626
627 __setup_btree_details(pmd);
628
629 r = dm_btree_empty(&pmd->info, &pmd->root);
630 if (r < 0)
631 goto bad_cleanup_nb_tm;
632
633 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
634 if (r < 0) {
635 DMERR("couldn't create devices root");
636 goto bad_cleanup_nb_tm;
637 }
638
639 r = __write_initial_superblock(pmd);
640 if (r)
641 goto bad_cleanup_nb_tm;
642
643 return 0;
644
645bad_cleanup_nb_tm:
646 dm_tm_destroy(pmd->nb_tm);
647 pmd->nb_tm = NULL;
648bad_cleanup_data_sm:
649 dm_sm_destroy(pmd->data_sm);
650 pmd->data_sm = NULL;
651bad_cleanup_tm:
652 dm_tm_destroy(pmd->tm);
653 pmd->tm = NULL;
654 dm_sm_destroy(pmd->metadata_sm);
655 pmd->metadata_sm = NULL;
656
657 return r;
658}
659
660static int __check_incompat_features(struct thin_disk_superblock *disk_super,
661 struct dm_pool_metadata *pmd)
662{
663 uint32_t features;
664
665 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
666 if (features) {
667 DMERR("could not access metadata due to unsupported optional features (%lx).",
668 (unsigned long)features);
669 return -EINVAL;
670 }
671
672 /*
673 * Check for read-only metadata to skip the following RDWR checks.
674 */
675 if (bdev_read_only(pmd->bdev))
676 return 0;
677
678 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
679 if (features) {
680 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
681 (unsigned long)features);
682 return -EINVAL;
683 }
684
685 return 0;
686}
687
688static int __open_metadata(struct dm_pool_metadata *pmd)
689{
690 int r;
691 struct dm_block *sblock;
692 struct thin_disk_superblock *disk_super;
693
694 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
695 &sb_validator, &sblock);
696 if (r < 0) {
697 DMERR("couldn't read superblock");
698 return r;
699 }
700
701 disk_super = dm_block_data(sblock);
702
703 /* Verify the data block size hasn't changed */
704 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
705 DMERR("changing the data block size (from %u to %llu) is not supported",
706 le32_to_cpu(disk_super->data_block_size),
707 (unsigned long long)pmd->data_block_size);
708 r = -EINVAL;
709 goto bad_unlock_sblock;
710 }
711
712 r = __check_incompat_features(disk_super, pmd);
713 if (r < 0)
714 goto bad_unlock_sblock;
715
716 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
717 disk_super->metadata_space_map_root,
718 sizeof(disk_super->metadata_space_map_root),
719 &pmd->tm, &pmd->metadata_sm);
720 if (r < 0) {
721 pmd->tm = NULL;
722 pmd->metadata_sm = NULL;
723 DMERR("tm_open_with_sm failed");
724 goto bad_unlock_sblock;
725 }
726
727 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
728 sizeof(disk_super->data_space_map_root));
729 if (IS_ERR(pmd->data_sm)) {
730 DMERR("sm_disk_open failed");
731 r = PTR_ERR(pmd->data_sm);
732 pmd->data_sm = NULL;
733 goto bad_cleanup_tm;
734 }
735
736 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
737 if (!pmd->nb_tm) {
738 DMERR("could not create non-blocking clone tm");
739 r = -ENOMEM;
740 goto bad_cleanup_data_sm;
741 }
742
743 /*
744 * For pool metadata opening process, root setting is redundant
745 * because it will be set again in __begin_transaction(). But dm
746 * pool aborting process really needs to get last transaction's
747 * root to avoid accessing broken btree.
748 */
749 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
750 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
751
752 __setup_btree_details(pmd);
753 dm_bm_unlock(sblock);
754
755 return 0;
756
757bad_cleanup_data_sm:
758 dm_sm_destroy(pmd->data_sm);
759 pmd->data_sm = NULL;
760bad_cleanup_tm:
761 dm_tm_destroy(pmd->tm);
762 pmd->tm = NULL;
763 dm_sm_destroy(pmd->metadata_sm);
764 pmd->metadata_sm = NULL;
765bad_unlock_sblock:
766 dm_bm_unlock(sblock);
767
768 return r;
769}
770
771static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
772{
773 int r, unformatted;
774
775 r = __superblock_all_zeroes(pmd->bm, &unformatted);
776 if (r)
777 return r;
778
779 if (unformatted)
780 return format_device ? __format_metadata(pmd) : -EPERM;
781
782 return __open_metadata(pmd);
783}
784
785static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
786{
787 int r;
788
789 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
790 THIN_MAX_CONCURRENT_LOCKS);
791 if (IS_ERR(pmd->bm)) {
792 DMERR("could not create block manager");
793 r = PTR_ERR(pmd->bm);
794 pmd->bm = NULL;
795 return r;
796 }
797
798 r = __open_or_format_metadata(pmd, format_device);
799 if (r) {
800 dm_block_manager_destroy(pmd->bm);
801 pmd->bm = NULL;
802 }
803
804 return r;
805}
806
807static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd,
808 bool destroy_bm)
809{
810 dm_sm_destroy(pmd->data_sm);
811 pmd->data_sm = NULL;
812 dm_sm_destroy(pmd->metadata_sm);
813 pmd->metadata_sm = NULL;
814 dm_tm_destroy(pmd->nb_tm);
815 pmd->nb_tm = NULL;
816 dm_tm_destroy(pmd->tm);
817 pmd->tm = NULL;
818 if (destroy_bm)
819 dm_block_manager_destroy(pmd->bm);
820}
821
822static int __begin_transaction(struct dm_pool_metadata *pmd)
823{
824 int r;
825 struct thin_disk_superblock *disk_super;
826 struct dm_block *sblock;
827
828 /*
829 * We re-read the superblock every time. Shouldn't need to do this
830 * really.
831 */
832 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
833 &sb_validator, &sblock);
834 if (r)
835 return r;
836
837 disk_super = dm_block_data(sblock);
838 pmd->time = le32_to_cpu(disk_super->time);
839 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
840 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
841 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
842 pmd->flags = le32_to_cpu(disk_super->flags);
843 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
844
845 dm_bm_unlock(sblock);
846 return 0;
847}
848
849static int __write_changed_details(struct dm_pool_metadata *pmd)
850{
851 int r;
852 struct dm_thin_device *td, *tmp;
853 struct disk_device_details details;
854 uint64_t key;
855
856 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
857 if (!td->changed)
858 continue;
859
860 key = td->id;
861
862 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
863 details.transaction_id = cpu_to_le64(td->transaction_id);
864 details.creation_time = cpu_to_le32(td->creation_time);
865 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
866 __dm_bless_for_disk(&details);
867
868 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
869 &key, &details, &pmd->details_root);
870 if (r)
871 return r;
872
873 if (td->open_count)
874 td->changed = false;
875 else {
876 list_del(&td->list);
877 kfree(td);
878 }
879 }
880
881 return 0;
882}
883
884static int __commit_transaction(struct dm_pool_metadata *pmd)
885{
886 int r;
887 struct thin_disk_superblock *disk_super;
888 struct dm_block *sblock;
889
890 /*
891 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
892 */
893 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
894 BUG_ON(!rwsem_is_locked(&pmd->root_lock));
895
896 if (unlikely(!pmd->in_service))
897 return 0;
898
899 if (pmd->pre_commit_fn) {
900 r = pmd->pre_commit_fn(pmd->pre_commit_context);
901 if (r < 0) {
902 DMERR("pre-commit callback failed");
903 return r;
904 }
905 }
906
907 r = __write_changed_details(pmd);
908 if (r < 0)
909 return r;
910
911 r = dm_sm_commit(pmd->data_sm);
912 if (r < 0)
913 return r;
914
915 r = dm_tm_pre_commit(pmd->tm);
916 if (r < 0)
917 return r;
918
919 r = save_sm_roots(pmd);
920 if (r < 0)
921 return r;
922
923 r = superblock_lock(pmd, &sblock);
924 if (r)
925 return r;
926
927 disk_super = dm_block_data(sblock);
928 disk_super->time = cpu_to_le32(pmd->time);
929 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
930 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
931 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
932 disk_super->flags = cpu_to_le32(pmd->flags);
933
934 copy_sm_roots(pmd, disk_super);
935
936 return dm_tm_commit(pmd->tm, sblock);
937}
938
939static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
940{
941 int r;
942 dm_block_t total;
943 dm_block_t max_blocks = 4096; /* 16M */
944
945 r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
946 if (r) {
947 DMERR("could not get size of metadata device");
948 pmd->metadata_reserve = max_blocks;
949 } else
950 pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
951}
952
953struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
954 sector_t data_block_size,
955 bool format_device)
956{
957 int r;
958 struct dm_pool_metadata *pmd;
959
960 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
961 if (!pmd) {
962 DMERR("could not allocate metadata struct");
963 return ERR_PTR(-ENOMEM);
964 }
965
966 init_rwsem(&pmd->root_lock);
967 pmd->time = 0;
968 INIT_LIST_HEAD(&pmd->thin_devices);
969 pmd->fail_io = false;
970 pmd->in_service = false;
971 pmd->bdev = bdev;
972 pmd->data_block_size = data_block_size;
973 pmd->pre_commit_fn = NULL;
974 pmd->pre_commit_context = NULL;
975
976 r = __create_persistent_data_objects(pmd, format_device);
977 if (r) {
978 kfree(pmd);
979 return ERR_PTR(r);
980 }
981
982 r = __begin_transaction(pmd);
983 if (r < 0) {
984 if (dm_pool_metadata_close(pmd) < 0)
985 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
986 return ERR_PTR(r);
987 }
988
989 __set_metadata_reserve(pmd);
990
991 return pmd;
992}
993
994int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
995{
996 int r;
997 unsigned int open_devices = 0;
998 struct dm_thin_device *td, *tmp;
999
1000 down_read(&pmd->root_lock);
1001 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1002 if (td->open_count)
1003 open_devices++;
1004 else {
1005 list_del(&td->list);
1006 kfree(td);
1007 }
1008 }
1009 up_read(&pmd->root_lock);
1010
1011 if (open_devices) {
1012 DMERR("attempt to close pmd when %u device(s) are still open",
1013 open_devices);
1014 return -EBUSY;
1015 }
1016
1017 pmd_write_lock_in_core(pmd);
1018 if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) {
1019 r = __commit_transaction(pmd);
1020 if (r < 0)
1021 DMWARN("%s: __commit_transaction() failed, error = %d",
1022 __func__, r);
1023 }
1024 pmd_write_unlock(pmd);
1025 __destroy_persistent_data_objects(pmd, true);
1026
1027 kfree(pmd);
1028 return 0;
1029}
1030
1031/*
1032 * __open_device: Returns @td corresponding to device with id @dev,
1033 * creating it if @create is set and incrementing @td->open_count.
1034 * On failure, @td is undefined.
1035 */
1036static int __open_device(struct dm_pool_metadata *pmd,
1037 dm_thin_id dev, int create,
1038 struct dm_thin_device **td)
1039{
1040 int r, changed = 0;
1041 struct dm_thin_device *td2;
1042 uint64_t key = dev;
1043 struct disk_device_details details_le;
1044
1045 /*
1046 * If the device is already open, return it.
1047 */
1048 list_for_each_entry(td2, &pmd->thin_devices, list)
1049 if (td2->id == dev) {
1050 /*
1051 * May not create an already-open device.
1052 */
1053 if (create)
1054 return -EEXIST;
1055
1056 td2->open_count++;
1057 *td = td2;
1058 return 0;
1059 }
1060
1061 /*
1062 * Check the device exists.
1063 */
1064 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1065 &key, &details_le);
1066 if (r) {
1067 if (r != -ENODATA || !create)
1068 return r;
1069
1070 /*
1071 * Create new device.
1072 */
1073 changed = 1;
1074 details_le.mapped_blocks = 0;
1075 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
1076 details_le.creation_time = cpu_to_le32(pmd->time);
1077 details_le.snapshotted_time = cpu_to_le32(pmd->time);
1078 }
1079
1080 *td = kmalloc(sizeof(**td), GFP_NOIO);
1081 if (!*td)
1082 return -ENOMEM;
1083
1084 (*td)->pmd = pmd;
1085 (*td)->id = dev;
1086 (*td)->open_count = 1;
1087 (*td)->changed = changed;
1088 (*td)->aborted_with_changes = false;
1089 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
1090 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
1091 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
1092 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
1093
1094 list_add(&(*td)->list, &pmd->thin_devices);
1095
1096 return 0;
1097}
1098
1099static void __close_device(struct dm_thin_device *td)
1100{
1101 --td->open_count;
1102}
1103
1104static int __create_thin(struct dm_pool_metadata *pmd,
1105 dm_thin_id dev)
1106{
1107 int r;
1108 dm_block_t dev_root;
1109 uint64_t key = dev;
1110 struct dm_thin_device *td;
1111 __le64 value;
1112
1113 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1114 &key, NULL);
1115 if (!r)
1116 return -EEXIST;
1117
1118 /*
1119 * Create an empty btree for the mappings.
1120 */
1121 r = dm_btree_empty(&pmd->bl_info, &dev_root);
1122 if (r)
1123 return r;
1124
1125 /*
1126 * Insert it into the main mapping tree.
1127 */
1128 value = cpu_to_le64(dev_root);
1129 __dm_bless_for_disk(&value);
1130 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1131 if (r) {
1132 dm_btree_del(&pmd->bl_info, dev_root);
1133 return r;
1134 }
1135
1136 r = __open_device(pmd, dev, 1, &td);
1137 if (r) {
1138 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1139 dm_btree_del(&pmd->bl_info, dev_root);
1140 return r;
1141 }
1142 __close_device(td);
1143
1144 return r;
1145}
1146
1147int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1148{
1149 int r = -EINVAL;
1150
1151 pmd_write_lock(pmd);
1152 if (!pmd->fail_io)
1153 r = __create_thin(pmd, dev);
1154 pmd_write_unlock(pmd);
1155
1156 return r;
1157}
1158
1159static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1160 struct dm_thin_device *snap,
1161 dm_thin_id origin, uint32_t time)
1162{
1163 int r;
1164 struct dm_thin_device *td;
1165
1166 r = __open_device(pmd, origin, 0, &td);
1167 if (r)
1168 return r;
1169
1170 td->changed = true;
1171 td->snapshotted_time = time;
1172
1173 snap->mapped_blocks = td->mapped_blocks;
1174 snap->snapshotted_time = time;
1175 __close_device(td);
1176
1177 return 0;
1178}
1179
1180static int __create_snap(struct dm_pool_metadata *pmd,
1181 dm_thin_id dev, dm_thin_id origin)
1182{
1183 int r;
1184 dm_block_t origin_root;
1185 uint64_t key = origin, dev_key = dev;
1186 struct dm_thin_device *td;
1187 __le64 value;
1188
1189 /* check this device is unused */
1190 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1191 &dev_key, NULL);
1192 if (!r)
1193 return -EEXIST;
1194
1195 /* find the mapping tree for the origin */
1196 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1197 if (r)
1198 return r;
1199 origin_root = le64_to_cpu(value);
1200
1201 /* clone the origin, an inc will do */
1202 dm_tm_inc(pmd->tm, origin_root);
1203
1204 /* insert into the main mapping tree */
1205 value = cpu_to_le64(origin_root);
1206 __dm_bless_for_disk(&value);
1207 key = dev;
1208 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1209 if (r) {
1210 dm_tm_dec(pmd->tm, origin_root);
1211 return r;
1212 }
1213
1214 pmd->time++;
1215
1216 r = __open_device(pmd, dev, 1, &td);
1217 if (r)
1218 goto bad;
1219
1220 r = __set_snapshot_details(pmd, td, origin, pmd->time);
1221 __close_device(td);
1222
1223 if (r)
1224 goto bad;
1225
1226 return 0;
1227
1228bad:
1229 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1230 dm_btree_remove(&pmd->details_info, pmd->details_root,
1231 &key, &pmd->details_root);
1232 return r;
1233}
1234
1235int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1236 dm_thin_id dev,
1237 dm_thin_id origin)
1238{
1239 int r = -EINVAL;
1240
1241 pmd_write_lock(pmd);
1242 if (!pmd->fail_io)
1243 r = __create_snap(pmd, dev, origin);
1244 pmd_write_unlock(pmd);
1245
1246 return r;
1247}
1248
1249static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1250{
1251 int r;
1252 uint64_t key = dev;
1253 struct dm_thin_device *td;
1254
1255 /* TODO: failure should mark the transaction invalid */
1256 r = __open_device(pmd, dev, 0, &td);
1257 if (r)
1258 return r;
1259
1260 if (td->open_count > 1) {
1261 __close_device(td);
1262 return -EBUSY;
1263 }
1264
1265 list_del(&td->list);
1266 kfree(td);
1267 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1268 &key, &pmd->details_root);
1269 if (r)
1270 return r;
1271
1272 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1273 if (r)
1274 return r;
1275
1276 return 0;
1277}
1278
1279int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1280 dm_thin_id dev)
1281{
1282 int r = -EINVAL;
1283
1284 pmd_write_lock(pmd);
1285 if (!pmd->fail_io)
1286 r = __delete_device(pmd, dev);
1287 pmd_write_unlock(pmd);
1288
1289 return r;
1290}
1291
1292int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1293 uint64_t current_id,
1294 uint64_t new_id)
1295{
1296 int r = -EINVAL;
1297
1298 pmd_write_lock(pmd);
1299
1300 if (pmd->fail_io)
1301 goto out;
1302
1303 if (pmd->trans_id != current_id) {
1304 DMERR("mismatched transaction id");
1305 goto out;
1306 }
1307
1308 pmd->trans_id = new_id;
1309 r = 0;
1310
1311out:
1312 pmd_write_unlock(pmd);
1313
1314 return r;
1315}
1316
1317int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1318 uint64_t *result)
1319{
1320 int r = -EINVAL;
1321
1322 down_read(&pmd->root_lock);
1323 if (!pmd->fail_io) {
1324 *result = pmd->trans_id;
1325 r = 0;
1326 }
1327 up_read(&pmd->root_lock);
1328
1329 return r;
1330}
1331
1332static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1333{
1334 int r, inc;
1335 struct thin_disk_superblock *disk_super;
1336 struct dm_block *copy, *sblock;
1337 dm_block_t held_root;
1338
1339 /*
1340 * We commit to ensure the btree roots which we increment in a
1341 * moment are up to date.
1342 */
1343 r = __commit_transaction(pmd);
1344 if (r < 0) {
1345 DMWARN("%s: __commit_transaction() failed, error = %d",
1346 __func__, r);
1347 return r;
1348 }
1349
1350 /*
1351 * Copy the superblock.
1352 */
1353 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1354 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1355 &sb_validator, ©, &inc);
1356 if (r)
1357 return r;
1358
1359 BUG_ON(!inc);
1360
1361 held_root = dm_block_location(copy);
1362 disk_super = dm_block_data(copy);
1363
1364 if (le64_to_cpu(disk_super->held_root)) {
1365 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1366
1367 dm_tm_dec(pmd->tm, held_root);
1368 dm_tm_unlock(pmd->tm, copy);
1369 return -EBUSY;
1370 }
1371
1372 /*
1373 * Wipe the spacemap since we're not publishing this.
1374 */
1375 memset(&disk_super->data_space_map_root, 0,
1376 sizeof(disk_super->data_space_map_root));
1377 memset(&disk_super->metadata_space_map_root, 0,
1378 sizeof(disk_super->metadata_space_map_root));
1379
1380 /*
1381 * Increment the data structures that need to be preserved.
1382 */
1383 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1384 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1385 dm_tm_unlock(pmd->tm, copy);
1386
1387 /*
1388 * Write the held root into the superblock.
1389 */
1390 r = superblock_lock(pmd, &sblock);
1391 if (r) {
1392 dm_tm_dec(pmd->tm, held_root);
1393 return r;
1394 }
1395
1396 disk_super = dm_block_data(sblock);
1397 disk_super->held_root = cpu_to_le64(held_root);
1398 dm_bm_unlock(sblock);
1399 return 0;
1400}
1401
1402int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1403{
1404 int r = -EINVAL;
1405
1406 pmd_write_lock(pmd);
1407 if (!pmd->fail_io)
1408 r = __reserve_metadata_snap(pmd);
1409 pmd_write_unlock(pmd);
1410
1411 return r;
1412}
1413
1414static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1415{
1416 int r;
1417 struct thin_disk_superblock *disk_super;
1418 struct dm_block *sblock, *copy;
1419 dm_block_t held_root;
1420
1421 r = superblock_lock(pmd, &sblock);
1422 if (r)
1423 return r;
1424
1425 disk_super = dm_block_data(sblock);
1426 held_root = le64_to_cpu(disk_super->held_root);
1427 disk_super->held_root = cpu_to_le64(0);
1428
1429 dm_bm_unlock(sblock);
1430
1431 if (!held_root) {
1432 DMWARN("No pool metadata snapshot found: nothing to release.");
1433 return -EINVAL;
1434 }
1435
1436 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©);
1437 if (r)
1438 return r;
1439
1440 disk_super = dm_block_data(copy);
1441 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
1442 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
1443 dm_sm_dec_block(pmd->metadata_sm, held_root);
1444
1445 dm_tm_unlock(pmd->tm, copy);
1446
1447 return 0;
1448}
1449
1450int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1451{
1452 int r = -EINVAL;
1453
1454 pmd_write_lock(pmd);
1455 if (!pmd->fail_io)
1456 r = __release_metadata_snap(pmd);
1457 pmd_write_unlock(pmd);
1458
1459 return r;
1460}
1461
1462static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1463 dm_block_t *result)
1464{
1465 int r;
1466 struct thin_disk_superblock *disk_super;
1467 struct dm_block *sblock;
1468
1469 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1470 &sb_validator, &sblock);
1471 if (r)
1472 return r;
1473
1474 disk_super = dm_block_data(sblock);
1475 *result = le64_to_cpu(disk_super->held_root);
1476
1477 dm_bm_unlock(sblock);
1478
1479 return 0;
1480}
1481
1482int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1483 dm_block_t *result)
1484{
1485 int r = -EINVAL;
1486
1487 down_read(&pmd->root_lock);
1488 if (!pmd->fail_io)
1489 r = __get_metadata_snap(pmd, result);
1490 up_read(&pmd->root_lock);
1491
1492 return r;
1493}
1494
1495int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1496 struct dm_thin_device **td)
1497{
1498 int r = -EINVAL;
1499
1500 pmd_write_lock_in_core(pmd);
1501 if (!pmd->fail_io)
1502 r = __open_device(pmd, dev, 0, td);
1503 pmd_write_unlock(pmd);
1504
1505 return r;
1506}
1507
1508int dm_pool_close_thin_device(struct dm_thin_device *td)
1509{
1510 pmd_write_lock_in_core(td->pmd);
1511 __close_device(td);
1512 pmd_write_unlock(td->pmd);
1513
1514 return 0;
1515}
1516
1517dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1518{
1519 return td->id;
1520}
1521
1522/*
1523 * Check whether @time (of block creation) is older than @td's last snapshot.
1524 * If so then the associated block is shared with the last snapshot device.
1525 * Any block on a device created *after* the device last got snapshotted is
1526 * necessarily not shared.
1527 */
1528static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1529{
1530 return td->snapshotted_time > time;
1531}
1532
1533static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
1534 struct dm_thin_lookup_result *result)
1535{
1536 uint64_t block_time = 0;
1537 dm_block_t exception_block;
1538 uint32_t exception_time;
1539
1540 block_time = le64_to_cpu(value);
1541 unpack_block_time(block_time, &exception_block, &exception_time);
1542 result->block = exception_block;
1543 result->shared = __snapshotted_since(td, exception_time);
1544}
1545
1546static int __find_block(struct dm_thin_device *td, dm_block_t block,
1547 int can_issue_io, struct dm_thin_lookup_result *result)
1548{
1549 int r;
1550 __le64 value;
1551 struct dm_pool_metadata *pmd = td->pmd;
1552 dm_block_t keys[2] = { td->id, block };
1553 struct dm_btree_info *info;
1554
1555 if (can_issue_io)
1556 info = &pmd->info;
1557 else
1558 info = &pmd->nb_info;
1559
1560 r = dm_btree_lookup(info, pmd->root, keys, &value);
1561 if (!r)
1562 unpack_lookup_result(td, value, result);
1563
1564 return r;
1565}
1566
1567int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1568 int can_issue_io, struct dm_thin_lookup_result *result)
1569{
1570 int r;
1571 struct dm_pool_metadata *pmd = td->pmd;
1572
1573 down_read(&pmd->root_lock);
1574 if (pmd->fail_io) {
1575 up_read(&pmd->root_lock);
1576 return -EINVAL;
1577 }
1578
1579 r = __find_block(td, block, can_issue_io, result);
1580
1581 up_read(&pmd->root_lock);
1582 return r;
1583}
1584
1585static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
1586 dm_block_t *vblock,
1587 struct dm_thin_lookup_result *result)
1588{
1589 int r;
1590 __le64 value;
1591 struct dm_pool_metadata *pmd = td->pmd;
1592 dm_block_t keys[2] = { td->id, block };
1593
1594 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1595 if (!r)
1596 unpack_lookup_result(td, value, result);
1597
1598 return r;
1599}
1600
1601static int __find_mapped_range(struct dm_thin_device *td,
1602 dm_block_t begin, dm_block_t end,
1603 dm_block_t *thin_begin, dm_block_t *thin_end,
1604 dm_block_t *pool_begin, bool *maybe_shared)
1605{
1606 int r;
1607 dm_block_t pool_end;
1608 struct dm_thin_lookup_result lookup;
1609
1610 if (end < begin)
1611 return -ENODATA;
1612
1613 r = __find_next_mapped_block(td, begin, &begin, &lookup);
1614 if (r)
1615 return r;
1616
1617 if (begin >= end)
1618 return -ENODATA;
1619
1620 *thin_begin = begin;
1621 *pool_begin = lookup.block;
1622 *maybe_shared = lookup.shared;
1623
1624 begin++;
1625 pool_end = *pool_begin + 1;
1626 while (begin != end) {
1627 r = __find_block(td, begin, true, &lookup);
1628 if (r) {
1629 if (r == -ENODATA)
1630 break;
1631
1632 return r;
1633 }
1634
1635 if ((lookup.block != pool_end) ||
1636 (lookup.shared != *maybe_shared))
1637 break;
1638
1639 pool_end++;
1640 begin++;
1641 }
1642
1643 *thin_end = begin;
1644 return 0;
1645}
1646
1647int dm_thin_find_mapped_range(struct dm_thin_device *td,
1648 dm_block_t begin, dm_block_t end,
1649 dm_block_t *thin_begin, dm_block_t *thin_end,
1650 dm_block_t *pool_begin, bool *maybe_shared)
1651{
1652 int r = -EINVAL;
1653 struct dm_pool_metadata *pmd = td->pmd;
1654
1655 down_read(&pmd->root_lock);
1656 if (!pmd->fail_io) {
1657 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
1658 pool_begin, maybe_shared);
1659 }
1660 up_read(&pmd->root_lock);
1661
1662 return r;
1663}
1664
1665static int __insert(struct dm_thin_device *td, dm_block_t block,
1666 dm_block_t data_block)
1667{
1668 int r, inserted;
1669 __le64 value;
1670 struct dm_pool_metadata *pmd = td->pmd;
1671 dm_block_t keys[2] = { td->id, block };
1672
1673 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1674 __dm_bless_for_disk(&value);
1675
1676 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1677 &pmd->root, &inserted);
1678 if (r)
1679 return r;
1680
1681 td->changed = true;
1682 if (inserted)
1683 td->mapped_blocks++;
1684
1685 return 0;
1686}
1687
1688int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1689 dm_block_t data_block)
1690{
1691 int r = -EINVAL;
1692
1693 pmd_write_lock(td->pmd);
1694 if (!td->pmd->fail_io)
1695 r = __insert(td, block, data_block);
1696 pmd_write_unlock(td->pmd);
1697
1698 return r;
1699}
1700
1701static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1702{
1703 int r;
1704 unsigned int count, total_count = 0;
1705 struct dm_pool_metadata *pmd = td->pmd;
1706 dm_block_t keys[1] = { td->id };
1707 __le64 value;
1708 dm_block_t mapping_root;
1709
1710 /*
1711 * Find the mapping tree
1712 */
1713 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
1714 if (r)
1715 return r;
1716
1717 /*
1718 * Remove from the mapping tree, taking care to inc the
1719 * ref count so it doesn't get deleted.
1720 */
1721 mapping_root = le64_to_cpu(value);
1722 dm_tm_inc(pmd->tm, mapping_root);
1723 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
1724 if (r)
1725 return r;
1726
1727 /*
1728 * Remove leaves stops at the first unmapped entry, so we have to
1729 * loop round finding mapped ranges.
1730 */
1731 while (begin < end) {
1732 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
1733 if (r == -ENODATA)
1734 break;
1735
1736 if (r)
1737 return r;
1738
1739 if (begin >= end)
1740 break;
1741
1742 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
1743 if (r)
1744 return r;
1745
1746 total_count += count;
1747 }
1748
1749 td->mapped_blocks -= total_count;
1750 td->changed = true;
1751
1752 /*
1753 * Reinsert the mapping tree.
1754 */
1755 value = cpu_to_le64(mapping_root);
1756 __dm_bless_for_disk(&value);
1757 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
1758}
1759
1760int dm_thin_remove_range(struct dm_thin_device *td,
1761 dm_block_t begin, dm_block_t end)
1762{
1763 int r = -EINVAL;
1764
1765 pmd_write_lock(td->pmd);
1766 if (!td->pmd->fail_io)
1767 r = __remove_range(td, begin, end);
1768 pmd_write_unlock(td->pmd);
1769
1770 return r;
1771}
1772
1773int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
1774{
1775 int r = -EINVAL;
1776 uint32_t ref_count;
1777
1778 down_read(&pmd->root_lock);
1779 if (!pmd->fail_io) {
1780 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
1781 if (!r)
1782 *result = (ref_count > 1);
1783 }
1784 up_read(&pmd->root_lock);
1785
1786 return r;
1787}
1788
1789int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1790{
1791 int r = -EINVAL;
1792
1793 pmd_write_lock(pmd);
1794 if (!pmd->fail_io)
1795 r = dm_sm_inc_blocks(pmd->data_sm, b, e);
1796 pmd_write_unlock(pmd);
1797
1798 return r;
1799}
1800
1801int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1802{
1803 int r = -EINVAL;
1804
1805 pmd_write_lock(pmd);
1806 if (!pmd->fail_io)
1807 r = dm_sm_dec_blocks(pmd->data_sm, b, e);
1808 pmd_write_unlock(pmd);
1809
1810 return r;
1811}
1812
1813bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1814{
1815 int r;
1816
1817 down_read(&td->pmd->root_lock);
1818 r = td->changed;
1819 up_read(&td->pmd->root_lock);
1820
1821 return r;
1822}
1823
1824bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
1825{
1826 bool r = false;
1827 struct dm_thin_device *td, *tmp;
1828
1829 down_read(&pmd->root_lock);
1830 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1831 if (td->changed) {
1832 r = td->changed;
1833 break;
1834 }
1835 }
1836 up_read(&pmd->root_lock);
1837
1838 return r;
1839}
1840
1841bool dm_thin_aborted_changes(struct dm_thin_device *td)
1842{
1843 bool r;
1844
1845 down_read(&td->pmd->root_lock);
1846 r = td->aborted_with_changes;
1847 up_read(&td->pmd->root_lock);
1848
1849 return r;
1850}
1851
1852int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1853{
1854 int r = -EINVAL;
1855
1856 pmd_write_lock(pmd);
1857 if (!pmd->fail_io)
1858 r = dm_sm_new_block(pmd->data_sm, result);
1859 pmd_write_unlock(pmd);
1860
1861 return r;
1862}
1863
1864int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1865{
1866 int r = -EINVAL;
1867
1868 /*
1869 * Care is taken to not have commit be what
1870 * triggers putting the thin-pool in-service.
1871 */
1872 pmd_write_lock_in_core(pmd);
1873 if (pmd->fail_io)
1874 goto out;
1875
1876 r = __commit_transaction(pmd);
1877 if (r < 0)
1878 goto out;
1879
1880 /*
1881 * Open the next transaction.
1882 */
1883 r = __begin_transaction(pmd);
1884out:
1885 pmd_write_unlock(pmd);
1886 return r;
1887}
1888
1889static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1890{
1891 struct dm_thin_device *td;
1892
1893 list_for_each_entry(td, &pmd->thin_devices, list)
1894 td->aborted_with_changes = td->changed;
1895}
1896
1897int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1898{
1899 int r = -EINVAL;
1900
1901 /* fail_io is double-checked with pmd->root_lock held below */
1902 if (unlikely(pmd->fail_io))
1903 return r;
1904
1905 pmd_write_lock(pmd);
1906 if (pmd->fail_io) {
1907 pmd_write_unlock(pmd);
1908 return r;
1909 }
1910 __set_abort_with_changes_flags(pmd);
1911
1912 /* destroy data_sm/metadata_sm/nb_tm/tm */
1913 __destroy_persistent_data_objects(pmd, false);
1914
1915 /* reset bm */
1916 dm_block_manager_reset(pmd->bm);
1917
1918 /* rebuild data_sm/metadata_sm/nb_tm/tm */
1919 r = __open_or_format_metadata(pmd, false);
1920 if (r)
1921 pmd->fail_io = true;
1922 pmd_write_unlock(pmd);
1923 return r;
1924}
1925
1926int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1927{
1928 int r = -EINVAL;
1929
1930 down_read(&pmd->root_lock);
1931 if (!pmd->fail_io)
1932 r = dm_sm_get_nr_free(pmd->data_sm, result);
1933 up_read(&pmd->root_lock);
1934
1935 return r;
1936}
1937
1938int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1939 dm_block_t *result)
1940{
1941 int r = -EINVAL;
1942
1943 down_read(&pmd->root_lock);
1944 if (!pmd->fail_io)
1945 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1946
1947 if (!r) {
1948 if (*result < pmd->metadata_reserve)
1949 *result = 0;
1950 else
1951 *result -= pmd->metadata_reserve;
1952 }
1953 up_read(&pmd->root_lock);
1954
1955 return r;
1956}
1957
1958int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1959 dm_block_t *result)
1960{
1961 int r = -EINVAL;
1962
1963 down_read(&pmd->root_lock);
1964 if (!pmd->fail_io)
1965 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1966 up_read(&pmd->root_lock);
1967
1968 return r;
1969}
1970
1971int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1972{
1973 int r = -EINVAL;
1974
1975 down_read(&pmd->root_lock);
1976 if (!pmd->fail_io)
1977 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1978 up_read(&pmd->root_lock);
1979
1980 return r;
1981}
1982
1983int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1984{
1985 int r = -EINVAL;
1986 struct dm_pool_metadata *pmd = td->pmd;
1987
1988 down_read(&pmd->root_lock);
1989 if (!pmd->fail_io) {
1990 *result = td->mapped_blocks;
1991 r = 0;
1992 }
1993 up_read(&pmd->root_lock);
1994
1995 return r;
1996}
1997
1998static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1999{
2000 int r;
2001 __le64 value_le;
2002 dm_block_t thin_root;
2003 struct dm_pool_metadata *pmd = td->pmd;
2004
2005 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
2006 if (r)
2007 return r;
2008
2009 thin_root = le64_to_cpu(value_le);
2010
2011 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
2012}
2013
2014int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
2015 dm_block_t *result)
2016{
2017 int r = -EINVAL;
2018 struct dm_pool_metadata *pmd = td->pmd;
2019
2020 down_read(&pmd->root_lock);
2021 if (!pmd->fail_io)
2022 r = __highest_block(td, result);
2023 up_read(&pmd->root_lock);
2024
2025 return r;
2026}
2027
2028static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
2029{
2030 int r;
2031 dm_block_t old_count;
2032
2033 r = dm_sm_get_nr_blocks(sm, &old_count);
2034 if (r)
2035 return r;
2036
2037 if (new_count == old_count)
2038 return 0;
2039
2040 if (new_count < old_count) {
2041 DMERR("cannot reduce size of space map");
2042 return -EINVAL;
2043 }
2044
2045 return dm_sm_extend(sm, new_count - old_count);
2046}
2047
2048int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
2049{
2050 int r = -EINVAL;
2051
2052 pmd_write_lock(pmd);
2053 if (!pmd->fail_io)
2054 r = __resize_space_map(pmd->data_sm, new_count);
2055 pmd_write_unlock(pmd);
2056
2057 return r;
2058}
2059
2060int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
2061{
2062 int r = -EINVAL;
2063
2064 pmd_write_lock(pmd);
2065 if (!pmd->fail_io) {
2066 r = __resize_space_map(pmd->metadata_sm, new_count);
2067 if (!r)
2068 __set_metadata_reserve(pmd);
2069 }
2070 pmd_write_unlock(pmd);
2071
2072 return r;
2073}
2074
2075void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
2076{
2077 pmd_write_lock_in_core(pmd);
2078 dm_bm_set_read_only(pmd->bm);
2079 pmd_write_unlock(pmd);
2080}
2081
2082void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
2083{
2084 pmd_write_lock_in_core(pmd);
2085 dm_bm_set_read_write(pmd->bm);
2086 pmd_write_unlock(pmd);
2087}
2088
2089int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
2090 dm_block_t threshold,
2091 dm_sm_threshold_fn fn,
2092 void *context)
2093{
2094 int r = -EINVAL;
2095
2096 pmd_write_lock_in_core(pmd);
2097 if (!pmd->fail_io) {
2098 r = dm_sm_register_threshold_callback(pmd->metadata_sm,
2099 threshold, fn, context);
2100 }
2101 pmd_write_unlock(pmd);
2102
2103 return r;
2104}
2105
2106void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
2107 dm_pool_pre_commit_fn fn,
2108 void *context)
2109{
2110 pmd_write_lock_in_core(pmd);
2111 pmd->pre_commit_fn = fn;
2112 pmd->pre_commit_context = context;
2113 pmd_write_unlock(pmd);
2114}
2115
2116int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
2117{
2118 int r = -EINVAL;
2119 struct dm_block *sblock;
2120 struct thin_disk_superblock *disk_super;
2121
2122 pmd_write_lock(pmd);
2123 if (pmd->fail_io)
2124 goto out;
2125
2126 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
2127
2128 r = superblock_lock(pmd, &sblock);
2129 if (r) {
2130 DMERR("couldn't lock superblock");
2131 goto out;
2132 }
2133
2134 disk_super = dm_block_data(sblock);
2135 disk_super->flags = cpu_to_le32(pmd->flags);
2136
2137 dm_bm_unlock(sblock);
2138out:
2139 pmd_write_unlock(pmd);
2140 return r;
2141}
2142
2143bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
2144{
2145 bool needs_check;
2146
2147 down_read(&pmd->root_lock);
2148 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
2149 up_read(&pmd->root_lock);
2150
2151 return needs_check;
2152}
2153
2154void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
2155{
2156 down_read(&pmd->root_lock);
2157 if (!pmd->fail_io)
2158 dm_tm_issue_prefetches(pmd->tm);
2159 up_read(&pmd->root_lock);
2160}