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