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Merge branch 'acpica'
[linux-2.6-block.git] / drivers / md / dm-thin-metadata.c
CommitLineData
991d9fa0 1/*
da105ed5 2 * Copyright (C) 2011-2012 Red Hat, Inc.
991d9fa0
JT		 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
07f2b6e0 79#define THIN_VERSION 2
991d9fa0
JT		 80#define THIN_METADATA_CACHE_SIZE 64
81#define SECTOR_TO_BLOCK_SHIFT 3
82
8c971178
JT		 83/*
84 * 3 for btree insert +
85 * 2 for btree lookup used within space map
86 */
87#define THIN_MAX_CONCURRENT_LOCKS 5
88
991d9fa0
JT		 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;
991d9fa0
JT		 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;
da105ed5
JT		 187
188 /*
189 * Set if a transaction has to be aborted but the attempt to roll back
190 * to the previous (good) transaction failed. The only pool metadata
191 * operation possible in this state is the closing of the device.
192 */
193 bool fail_io:1;
5a32083d
JT		 194
195 /*
196 * Reading the space map roots can fail, so we read it into these
197 * buffers before the superblock is locked and updated.
198 */
199 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
200 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
991d9fa0
JT		 201};
202
203struct dm_thin_device {
204 struct list_head list;
205 struct dm_pool_metadata *pmd;
206 dm_thin_id id;
207
208 int open_count;
da105ed5
JT		 209 bool changed:1;
210 bool aborted_with_changes:1;
991d9fa0
JT		 211 uint64_t mapped_blocks;
212 uint64_t transaction_id;
213 uint32_t creation_time;
214 uint32_t snapshotted_time;
215};
216
217/*----------------------------------------------------------------
218 * superblock validator
219 *--------------------------------------------------------------*/
220
221#define SUPERBLOCK_CSUM_XOR 160774
222
223static void sb_prepare_for_write(struct dm_block_validator *v,
224 struct dm_block *b,
225 size_t block_size)
226{
227 struct thin_disk_superblock *disk_super = dm_block_data(b);
228
229 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
230 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
231 block_size - sizeof(__le32),
232 SUPERBLOCK_CSUM_XOR));
233}
234
235static int sb_check(struct dm_block_validator *v,
236 struct dm_block *b,
237 size_t block_size)
238{
239 struct thin_disk_superblock *disk_super = dm_block_data(b);
240 __le32 csum_le;
241
242 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
243 DMERR("sb_check failed: blocknr %llu: "
244 "wanted %llu", le64_to_cpu(disk_super->blocknr),
245 (unsigned long long)dm_block_location(b));
246 return -ENOTBLK;
247 }
248
249 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
250 DMERR("sb_check failed: magic %llu: "
251 "wanted %llu", le64_to_cpu(disk_super->magic),
252 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
253 return -EILSEQ;
254 }
255
256 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
257 block_size - sizeof(__le32),
258 SUPERBLOCK_CSUM_XOR));
259 if (csum_le != disk_super->csum) {
260 DMERR("sb_check failed: csum %u: wanted %u",
261 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
262 return -EILSEQ;
263 }
264
265 return 0;
266}
267
268static struct dm_block_validator sb_validator = {
269 .name = "superblock",
270 .prepare_for_write = sb_prepare_for_write,
271 .check = sb_check
272};
273
274/*----------------------------------------------------------------
275 * Methods for the btree value types
276 *--------------------------------------------------------------*/
277
278static uint64_t pack_block_time(dm_block_t b, uint32_t t)
279{
280 return (b << 24) | t;
281}
282
283static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
284{
285 *b = v >> 24;
286 *t = v & ((1 << 24) - 1);
287}
288
018cede9 289static void data_block_inc(void *context, const void *value_le)
991d9fa0
JT		 290{
291 struct dm_space_map *sm = context;
292 __le64 v_le;
293 uint64_t b;
294 uint32_t t;
295
296 memcpy(&v_le, value_le, sizeof(v_le));
297 unpack_block_time(le64_to_cpu(v_le), &b, &t);
298 dm_sm_inc_block(sm, b);
299}
300
018cede9 301static void data_block_dec(void *context, const void *value_le)
991d9fa0
JT		 302{
303 struct dm_space_map *sm = context;
304 __le64 v_le;
305 uint64_t b;
306 uint32_t t;
307
308 memcpy(&v_le, value_le, sizeof(v_le));
309 unpack_block_time(le64_to_cpu(v_le), &b, &t);
310 dm_sm_dec_block(sm, b);
311}
312
018cede9 313static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
991d9fa0
JT		 314{
315 __le64 v1_le, v2_le;
316 uint64_t b1, b2;
317 uint32_t t;
318
319 memcpy(&v1_le, value1_le, sizeof(v1_le));
320 memcpy(&v2_le, value2_le, sizeof(v2_le));
321 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
322 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
323
324 return b1 == b2;
325}
326
018cede9 327static void subtree_inc(void *context, const void *value)
991d9fa0
JT		 328{
329 struct dm_btree_info *info = context;
330 __le64 root_le;
331 uint64_t root;
332
333 memcpy(&root_le, value, sizeof(root_le));
334 root = le64_to_cpu(root_le);
335 dm_tm_inc(info->tm, root);
336}
337
018cede9 338static void subtree_dec(void *context, const void *value)
991d9fa0
JT		 339{
340 struct dm_btree_info *info = context;
341 __le64 root_le;
342 uint64_t root;
343
344 memcpy(&root_le, value, sizeof(root_le));
345 root = le64_to_cpu(root_le);
346 if (dm_btree_del(info, root))
29f929b5 347 DMERR("btree delete failed");
991d9fa0
JT		 348}
349
018cede9 350static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
991d9fa0
JT		 351{
352 __le64 v1_le, v2_le;
353 memcpy(&v1_le, value1_le, sizeof(v1_le));
354 memcpy(&v2_le, value2_le, sizeof(v2_le));
355
356 return v1_le == v2_le;
357}
358
359/*----------------------------------------------------------------*/
360
25971192
JT		 361static int superblock_lock_zero(struct dm_pool_metadata *pmd,
362 struct dm_block **sblock)
363{
364 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
365 &sb_validator, sblock);
366}
367
368static int superblock_lock(struct dm_pool_metadata *pmd,
369 struct dm_block **sblock)
370{
371 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
372 &sb_validator, sblock);
373}
374
332627db 375static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
991d9fa0
JT		 376{
377 int r;
378 unsigned i;
379 struct dm_block *b;
380 __le64 *data_le, zero = cpu_to_le64(0);
381 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
382
383 /*
384 * We can't use a validator here - it may be all zeroes.
385 */
386 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
387 if (r)
388 return r;
389
390 data_le = dm_block_data(b);
391 *result = 1;
392 for (i = 0; i < block_size; i++) {
393 if (data_le[i] != zero) {
394 *result = 0;
395 break;
396 }
397 }
398
4c7da06f
MP		 399 dm_bm_unlock(b);
400
401 return 0;
991d9fa0
JT		 402}
403
41675aea
JT		 404static void __setup_btree_details(struct dm_pool_metadata *pmd)
405{
406 pmd->info.tm = pmd->tm;
407 pmd->info.levels = 2;
408 pmd->info.value_type.context = pmd->data_sm;
409 pmd->info.value_type.size = sizeof(__le64);
410 pmd->info.value_type.inc = data_block_inc;
411 pmd->info.value_type.dec = data_block_dec;
412 pmd->info.value_type.equal = data_block_equal;
413
414 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
415 pmd->nb_info.tm = pmd->nb_tm;
416
417 pmd->tl_info.tm = pmd->tm;
418 pmd->tl_info.levels = 1;
e3cbf945 419 pmd->tl_info.value_type.context = &pmd->bl_info;
41675aea
JT		 420 pmd->tl_info.value_type.size = sizeof(__le64);
421 pmd->tl_info.value_type.inc = subtree_inc;
422 pmd->tl_info.value_type.dec = subtree_dec;
423 pmd->tl_info.value_type.equal = subtree_equal;
424
425 pmd->bl_info.tm = pmd->tm;
426 pmd->bl_info.levels = 1;
427 pmd->bl_info.value_type.context = pmd->data_sm;
428 pmd->bl_info.value_type.size = sizeof(__le64);
429 pmd->bl_info.value_type.inc = data_block_inc;
430 pmd->bl_info.value_type.dec = data_block_dec;
431 pmd->bl_info.value_type.equal = data_block_equal;
432
433 pmd->details_info.tm = pmd->tm;
434 pmd->details_info.levels = 1;
435 pmd->details_info.value_type.context = NULL;
436 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
437 pmd->details_info.value_type.inc = NULL;
438 pmd->details_info.value_type.dec = NULL;
439 pmd->details_info.value_type.equal = NULL;
440}
441
5a32083d
JT		 442static int save_sm_roots(struct dm_pool_metadata *pmd)
443{
444 int r;
445 size_t len;
446
447 r = dm_sm_root_size(pmd->metadata_sm, &len);
448 if (r < 0)
449 return r;
450
451 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
452 if (r < 0)
453 return r;
454
455 r = dm_sm_root_size(pmd->data_sm, &len);
456 if (r < 0)
457 return r;
458
459 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
460}
461
462static void copy_sm_roots(struct dm_pool_metadata *pmd,
463 struct thin_disk_superblock *disk)
464{
465 memcpy(&disk->metadata_space_map_root,
466 &pmd->metadata_space_map_root,
467 sizeof(pmd->metadata_space_map_root));
468
469 memcpy(&disk->data_space_map_root,
470 &pmd->data_space_map_root,
471 sizeof(pmd->data_space_map_root));
472}
473
9cb6653f
JT		 474static int __write_initial_superblock(struct dm_pool_metadata *pmd)
475{
476 int r;
477 struct dm_block *sblock;
478 struct thin_disk_superblock *disk_super;
479 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
480
481 if (bdev_size > THIN_METADATA_MAX_SECTORS)
482 bdev_size = THIN_METADATA_MAX_SECTORS;
483
5a32083d 484 r = dm_sm_commit(pmd->data_sm);
10d2a9ff
JT		 485 if (r < 0)
486 return r;
487
5a32083d 488 r = save_sm_roots(pmd);
10d2a9ff
JT		 489 if (r < 0)
490 return r;
491
492 r = dm_tm_pre_commit(pmd->tm);
493 if (r < 0)
494 return r;
495
9cb6653f
JT		 496 r = superblock_lock_zero(pmd, &sblock);
497 if (r)
498 return r;
499
500 disk_super = dm_block_data(sblock);
10d2a9ff 501 disk_super->flags = 0;
583ceee2 502 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
9cb6653f
JT		 503 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
504 disk_super->version = cpu_to_le32(THIN_VERSION);
505 disk_super->time = 0;
10d2a9ff
JT		 506 disk_super->trans_id = 0;
507 disk_super->held_root = 0;
508
5a32083d 509 copy_sm_roots(pmd, disk_super);
10d2a9ff
JT		 510
511 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
512 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
7d48935e 513 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
9cb6653f
JT		 514 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
515 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
516
270938ba 517 return dm_tm_commit(pmd->tm, sblock);
9cb6653f
JT		 518}
519
a97e5e6f 520static int __format_metadata(struct dm_pool_metadata *pmd)
991d9fa0
JT		 521{
522 int r;
384ef0e6 523
e4d2205c
JT		 524 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
525 &pmd->tm, &pmd->metadata_sm);
526 if (r < 0) {
527 DMERR("tm_create_with_sm failed");
528 return r;
529 }
991d9fa0 530
a97e5e6f 531 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
e4d2205c
JT		 532 if (IS_ERR(pmd->data_sm)) {
533 DMERR("sm_disk_create failed");
534 r = PTR_ERR(pmd->data_sm);
0fa5b17b 535 goto bad_cleanup_tm;
991d9fa0
JT		 536 }
537
d6332814 538 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
991d9fa0 539 if (!pmd->nb_tm) {
0fa5b17b 540 DMERR("could not create non-blocking clone tm");
991d9fa0 541 r = -ENOMEM;
0fa5b17b 542 goto bad_cleanup_data_sm;
991d9fa0
JT		 543 }
544
41675aea 545 __setup_btree_details(pmd);
991d9fa0 546
9cb6653f
JT		 547 r = dm_btree_empty(&pmd->info, &pmd->root);
548 if (r < 0)
0fa5b17b 549 goto bad_cleanup_nb_tm;
9cb6653f
JT		 550
551 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
552 if (r < 0) {
553 DMERR("couldn't create devices root");
0fa5b17b 554 goto bad_cleanup_nb_tm;
9cb6653f
JT		 555 }
556
557 r = __write_initial_superblock(pmd);
558 if (r)
0fa5b17b 559 goto bad_cleanup_nb_tm;
9cb6653f 560
991d9fa0
JT		 561 return 0;
562
0fa5b17b
JT		 563bad_cleanup_nb_tm:
564 dm_tm_destroy(pmd->nb_tm);
565bad_cleanup_data_sm:
d6332814 566 dm_sm_destroy(pmd->data_sm);
0fa5b17b 567bad_cleanup_tm:
d6332814
JT		 568 dm_tm_destroy(pmd->tm);
569 dm_sm_destroy(pmd->metadata_sm);
991d9fa0
JT		 570
571 return r;
572}
573
d73ec525
MS		 574static int __check_incompat_features(struct thin_disk_superblock *disk_super,
575 struct dm_pool_metadata *pmd)
576{
577 uint32_t features;
578
579 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
580 if (features) {
581 DMERR("could not access metadata due to unsupported optional features (%lx).",
582 (unsigned long)features);
583 return -EINVAL;
584 }
585
586 /*
587 * Check for read-only metadata to skip the following RDWR checks.
588 */
589 if (get_disk_ro(pmd->bdev->bd_disk))
590 return 0;
591
592 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
593 if (features) {
594 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
595 (unsigned long)features);
596 return -EINVAL;
597 }
598
599 return 0;
600}
601
e4d2205c
JT		 602static int __open_metadata(struct dm_pool_metadata *pmd)
603{
604 int r;
605 struct dm_block *sblock;
606 struct thin_disk_superblock *disk_super;
607
608 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
609 &sb_validator, &sblock);
610 if (r < 0) {
611 DMERR("couldn't read superblock");
612 return r;
613 }
614
615 disk_super = dm_block_data(sblock);
d73ec525 616
9aec8629
MS		 617 /* Verify the data block size hasn't changed */
618 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
619 DMERR("changing the data block size (from %u to %llu) is not supported",
620 le32_to_cpu(disk_super->data_block_size),
621 (unsigned long long)pmd->data_block_size);
622 r = -EINVAL;
623 goto bad_unlock_sblock;
624 }
625
d73ec525 626 r = __check_incompat_features(disk_super, pmd);
0fa5b17b
JT		 627 if (r < 0)
628 goto bad_unlock_sblock;
d73ec525 629
e4d2205c
JT		 630 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
631 disk_super->metadata_space_map_root,
632 sizeof(disk_super->metadata_space_map_root),
633 &pmd->tm, &pmd->metadata_sm);
634 if (r < 0) {
635 DMERR("tm_open_with_sm failed");
0fa5b17b 636 goto bad_unlock_sblock;
e4d2205c
JT		 637 }
638
639 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
640 sizeof(disk_super->data_space_map_root));
641 if (IS_ERR(pmd->data_sm)) {
642 DMERR("sm_disk_open failed");
e4d2205c 643 r = PTR_ERR(pmd->data_sm);
0fa5b17b 644 goto bad_cleanup_tm;
e4d2205c
JT		 645 }
646
e4d2205c
JT		 647 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
648 if (!pmd->nb_tm) {
0fa5b17b 649 DMERR("could not create non-blocking clone tm");
e4d2205c 650 r = -ENOMEM;
0fa5b17b 651 goto bad_cleanup_data_sm;
e4d2205c
JT		 652 }
653
654 __setup_btree_details(pmd);
4c7da06f
MP		 655 dm_bm_unlock(sblock);
656
657 return 0;
e4d2205c 658
0fa5b17b 659bad_cleanup_data_sm:
e4d2205c 660 dm_sm_destroy(pmd->data_sm);
0fa5b17b 661bad_cleanup_tm:
e4d2205c
JT		 662 dm_tm_destroy(pmd->tm);
663 dm_sm_destroy(pmd->metadata_sm);
0fa5b17b
JT		 664bad_unlock_sblock:
665 dm_bm_unlock(sblock);
e4d2205c
JT		 666
667 return r;
668}
669
66b1edc0 670static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
e4d2205c 671{
8801e069 672 int r, unformatted;
237074c0 673
8801e069 674 r = __superblock_all_zeroes(pmd->bm, &unformatted);
237074c0
JT		 675 if (r)
676 return r;
677
8801e069 678 if (unformatted)
66b1edc0
JT		 679 return format_device ? __format_metadata(pmd) : -EPERM;
680
681 return __open_metadata(pmd);
e4d2205c
JT		 682}
683
66b1edc0 684static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
332627db
JT		 685{
686 int r;
687
7d48935e 688 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
332627db
JT		 689 THIN_METADATA_CACHE_SIZE,
690 THIN_MAX_CONCURRENT_LOCKS);
691 if (IS_ERR(pmd->bm)) {
692 DMERR("could not create block manager");
693 return PTR_ERR(pmd->bm);
694 }
695
66b1edc0 696 r = __open_or_format_metadata(pmd, format_device);
332627db
JT		 697 if (r)
698 dm_block_manager_destroy(pmd->bm);
699
700 return r;
701}
702
f9dd9352
JT		 703static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
704{
705 dm_sm_destroy(pmd->data_sm);
706 dm_sm_destroy(pmd->metadata_sm);
707 dm_tm_destroy(pmd->nb_tm);
708 dm_tm_destroy(pmd->tm);
709 dm_block_manager_destroy(pmd->bm);
710}
711
991d9fa0
JT		 712static int __begin_transaction(struct dm_pool_metadata *pmd)
713{
714 int r;
991d9fa0
JT		 715 struct thin_disk_superblock *disk_super;
716 struct dm_block *sblock;
717
991d9fa0
JT		 718 /*
719 * We re-read the superblock every time. Shouldn't need to do this
720 * really.
721 */
722 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
723 &sb_validator, &sblock);
724 if (r)
725 return r;
726
727 disk_super = dm_block_data(sblock);
728 pmd->time = le32_to_cpu(disk_super->time);
729 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
730 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
731 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
732 pmd->flags = le32_to_cpu(disk_super->flags);
733 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
734
991d9fa0 735 dm_bm_unlock(sblock);
d73ec525 736 return 0;
991d9fa0
JT		 737}
738
739static int __write_changed_details(struct dm_pool_metadata *pmd)
740{
741 int r;
742 struct dm_thin_device *td, *tmp;
743 struct disk_device_details details;
744 uint64_t key;
745
746 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
747 if (!td->changed)
748 continue;
749
750 key = td->id;
751
752 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
753 details.transaction_id = cpu_to_le64(td->transaction_id);
754 details.creation_time = cpu_to_le32(td->creation_time);
755 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
756 __dm_bless_for_disk(&details);
757
758 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
759 &key, &details, &pmd->details_root);
760 if (r)
761 return r;
762
763 if (td->open_count)
764 td->changed = 0;
765 else {
766 list_del(&td->list);
767 kfree(td);
768 }
991d9fa0
JT		 769 }
770
771 return 0;
772}
773
774static int __commit_transaction(struct dm_pool_metadata *pmd)
775{
991d9fa0
JT		 776 int r;
777 size_t metadata_len, data_len;
778 struct thin_disk_superblock *disk_super;
779 struct dm_block *sblock;
780
781 /*
782 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
783 */
784 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
785
786 r = __write_changed_details(pmd);
787 if (r < 0)
d973ac19 788 return r;
991d9fa0 789
991d9fa0
JT		 790 r = dm_sm_commit(pmd->data_sm);
791 if (r < 0)
d973ac19 792 return r;
991d9fa0
JT		 793
794 r = dm_tm_pre_commit(pmd->tm);
795 if (r < 0)
d973ac19 796 return r;
991d9fa0
JT		 797
798 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
799 if (r < 0)
d973ac19 800 return r;
991d9fa0 801
fef838cc 802 r = dm_sm_root_size(pmd->data_sm, &data_len);
991d9fa0 803 if (r < 0)
d973ac19 804 return r;
991d9fa0 805
5a32083d
JT		 806 r = save_sm_roots(pmd);
807 if (r < 0)
808 return r;
809
25971192 810 r = superblock_lock(pmd, &sblock);
991d9fa0 811 if (r)
d973ac19 812 return r;
991d9fa0
JT		 813
814 disk_super = dm_block_data(sblock);
815 disk_super->time = cpu_to_le32(pmd->time);
816 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
817 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
818 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
819 disk_super->flags = cpu_to_le32(pmd->flags);
820
5a32083d 821 copy_sm_roots(pmd, disk_super);
991d9fa0 822
eb04cf63 823 return dm_tm_commit(pmd->tm, sblock);
991d9fa0
JT		 824}
825
826struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
66b1edc0
JT		 827 sector_t data_block_size,
828 bool format_device)
991d9fa0
JT		 829{
830 int r;
991d9fa0 831 struct dm_pool_metadata *pmd;
991d9fa0
JT		 832
833 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
834 if (!pmd) {
835 DMERR("could not allocate metadata struct");
836 return ERR_PTR(-ENOMEM);
837 }
838
6a0ebd31
JT		 839 init_rwsem(&pmd->root_lock);
840 pmd->time = 0;
841 INIT_LIST_HEAD(&pmd->thin_devices);
da105ed5 842 pmd->fail_io = false;
332627db 843 pmd->bdev = bdev;
9cb6653f 844 pmd->data_block_size = data_block_size;
991d9fa0 845
66b1edc0 846 r = __create_persistent_data_objects(pmd, format_device);
991d9fa0 847 if (r) {
991d9fa0
JT		 848 kfree(pmd);
849 return ERR_PTR(r);
850 }
991d9fa0 851
270938ba
JT		 852 r = __begin_transaction(pmd);
853 if (r < 0) {
854 if (dm_pool_metadata_close(pmd) < 0)
855 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
856 return ERR_PTR(r);
991d9fa0
JT		 857 }
858
859 return pmd;
991d9fa0
JT		 860}
861
862int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
863{
864 int r;
865 unsigned open_devices = 0;
866 struct dm_thin_device *td, *tmp;
867
868 down_read(&pmd->root_lock);
869 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
870 if (td->open_count)
871 open_devices++;
872 else {
873 list_del(&td->list);
874 kfree(td);
875 }
876 }
877 up_read(&pmd->root_lock);
878
879 if (open_devices) {
880 DMERR("attempt to close pmd when %u device(s) are still open",
881 open_devices);
882 return -EBUSY;
883 }
884
49f154c7 885 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
12ba58af
JT		 886 r = __commit_transaction(pmd);
887 if (r < 0)
888 DMWARN("%s: __commit_transaction() failed, error = %d",
889 __func__, r);
890 }
991d9fa0 891
da105ed5
JT		 892 if (!pmd->fail_io)
893 __destroy_persistent_data_objects(pmd);
991d9fa0 894
da105ed5 895 kfree(pmd);
991d9fa0
JT		 896 return 0;
897}
898
1f3db25d
MS		 899/*
900 * __open_device: Returns @td corresponding to device with id @dev,
901 * creating it if @create is set and incrementing @td->open_count.
902 * On failure, @td is undefined.
903 */
991d9fa0
JT		 904static int __open_device(struct dm_pool_metadata *pmd,
905 dm_thin_id dev, int create,
906 struct dm_thin_device **td)
907{
908 int r, changed = 0;
909 struct dm_thin_device *td2;
910 uint64_t key = dev;
911 struct disk_device_details details_le;
912
913 /*
1f3db25d 914 * If the device is already open, return it.
991d9fa0
JT		 915 */
916 list_for_each_entry(td2, &pmd->thin_devices, list)
917 if (td2->id == dev) {
1f3db25d
MS		 918 /*
919 * May not create an already-open device.
920 */
921 if (create)
922 return -EEXIST;
923
991d9fa0
JT		 924 td2->open_count++;
925 *td = td2;
926 return 0;
927 }
928
929 /*
930 * Check the device exists.
931 */
932 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
933 &key, &details_le);
934 if (r) {
935 if (r != -ENODATA || !create)
936 return r;
937
1f3db25d
MS		 938 /*
939 * Create new device.
940 */
991d9fa0
JT		 941 changed = 1;
942 details_le.mapped_blocks = 0;
943 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
944 details_le.creation_time = cpu_to_le32(pmd->time);
945 details_le.snapshotted_time = cpu_to_le32(pmd->time);
946 }
947
948 *td = kmalloc(sizeof(**td), GFP_NOIO);
949 if (!*td)
950 return -ENOMEM;
951
952 (*td)->pmd = pmd;
953 (*td)->id = dev;
954 (*td)->open_count = 1;
955 (*td)->changed = changed;
da105ed5 956 (*td)->aborted_with_changes = false;
991d9fa0
JT		 957 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
958 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
959 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
960 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
961
962 list_add(&(*td)->list, &pmd->thin_devices);
963
964 return 0;
965}
966
967static void __close_device(struct dm_thin_device *td)
968{
969 --td->open_count;
970}
971
972static int __create_thin(struct dm_pool_metadata *pmd,
973 dm_thin_id dev)
974{
975 int r;
976 dm_block_t dev_root;
977 uint64_t key = dev;
978 struct disk_device_details details_le;
979 struct dm_thin_device *td;
980 __le64 value;
981
982 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
983 &key, &details_le);
984 if (!r)
985 return -EEXIST;
986
987 /*
988 * Create an empty btree for the mappings.
989 */
990 r = dm_btree_empty(&pmd->bl_info, &dev_root);
991 if (r)
992 return r;
993
994 /*
995 * Insert it into the main mapping tree.
996 */
997 value = cpu_to_le64(dev_root);
998 __dm_bless_for_disk(&value);
999 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1000 if (r) {
1001 dm_btree_del(&pmd->bl_info, dev_root);
1002 return r;
1003 }
1004
1005 r = __open_device(pmd, dev, 1, &td);
1006 if (r) {
991d9fa0
JT		 1007 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1008 dm_btree_del(&pmd->bl_info, dev_root);
1009 return r;
1010 }
991d9fa0
JT		 1011 __close_device(td);
1012
1013 return r;
1014}
1015
1016int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1017{
da105ed5 1018 int r = -EINVAL;
991d9fa0
JT		 1019
1020 down_write(&pmd->root_lock);
da105ed5
JT		 1021 if (!pmd->fail_io)
1022 r = __create_thin(pmd, dev);
991d9fa0
JT		 1023 up_write(&pmd->root_lock);
1024
1025 return r;
1026}
1027
1028static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1029 struct dm_thin_device *snap,
1030 dm_thin_id origin, uint32_t time)
1031{
1032 int r;
1033 struct dm_thin_device *td;
1034
1035 r = __open_device(pmd, origin, 0, &td);
1036 if (r)
1037 return r;
1038
1039 td->changed = 1;
1040 td->snapshotted_time = time;
1041
1042 snap->mapped_blocks = td->mapped_blocks;
1043 snap->snapshotted_time = time;
1044 __close_device(td);
1045
1046 return 0;
1047}
1048
1049static int __create_snap(struct dm_pool_metadata *pmd,
1050 dm_thin_id dev, dm_thin_id origin)
1051{
1052 int r;
1053 dm_block_t origin_root;
1054 uint64_t key = origin, dev_key = dev;
1055 struct dm_thin_device *td;
1056 struct disk_device_details details_le;
1057 __le64 value;
1058
1059 /* check this device is unused */
1060 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1061 &dev_key, &details_le);
1062 if (!r)
1063 return -EEXIST;
1064
1065 /* find the mapping tree for the origin */
1066 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1067 if (r)
1068 return r;
1069 origin_root = le64_to_cpu(value);
1070
1071 /* clone the origin, an inc will do */
1072 dm_tm_inc(pmd->tm, origin_root);
1073
1074 /* insert into the main mapping tree */
1075 value = cpu_to_le64(origin_root);
1076 __dm_bless_for_disk(&value);
1077 key = dev;
1078 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1079 if (r) {
1080 dm_tm_dec(pmd->tm, origin_root);
1081 return r;
1082 }
1083
1084 pmd->time++;
1085
1086 r = __open_device(pmd, dev, 1, &td);
1087 if (r)
1088 goto bad;
1089
1090 r = __set_snapshot_details(pmd, td, origin, pmd->time);
1f3db25d
MS		 1091 __close_device(td);
1092
991d9fa0
JT		 1093 if (r)
1094 goto bad;
1095
991d9fa0
JT		 1096 return 0;
1097
1098bad:
991d9fa0
JT		 1099 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1100 dm_btree_remove(&pmd->details_info, pmd->details_root,
1101 &key, &pmd->details_root);
1102 return r;
1103}
1104
1105int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1106 dm_thin_id dev,
1107 dm_thin_id origin)
1108{
da105ed5 1109 int r = -EINVAL;
991d9fa0
JT		 1110
1111 down_write(&pmd->root_lock);
da105ed5
JT		 1112 if (!pmd->fail_io)
1113 r = __create_snap(pmd, dev, origin);
991d9fa0
JT		 1114 up_write(&pmd->root_lock);
1115
1116 return r;
1117}
1118
1119static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1120{
1121 int r;
1122 uint64_t key = dev;
1123 struct dm_thin_device *td;
1124
1125 /* TODO: failure should mark the transaction invalid */
1126 r = __open_device(pmd, dev, 0, &td);
1127 if (r)
1128 return r;
1129
1130 if (td->open_count > 1) {
1131 __close_device(td);
1132 return -EBUSY;
1133 }
1134
1135 list_del(&td->list);
1136 kfree(td);
1137 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1138 &key, &pmd->details_root);
1139 if (r)
1140 return r;
1141
1142 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1143 if (r)
1144 return r;
1145
991d9fa0
JT		 1146 return 0;
1147}
1148
1149int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1150 dm_thin_id dev)
1151{
da105ed5 1152 int r = -EINVAL;
991d9fa0
JT		 1153
1154 down_write(&pmd->root_lock);
da105ed5
JT		 1155 if (!pmd->fail_io)
1156 r = __delete_device(pmd, dev);
991d9fa0
JT		 1157 up_write(&pmd->root_lock);
1158
1159 return r;
1160}
1161
1162int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1163 uint64_t current_id,
1164 uint64_t new_id)
1165{
da105ed5
JT		 1166 int r = -EINVAL;
1167
991d9fa0 1168 down_write(&pmd->root_lock);
da105ed5
JT		 1169
1170 if (pmd->fail_io)
1171 goto out;
1172
991d9fa0 1173 if (pmd->trans_id != current_id) {
991d9fa0 1174 DMERR("mismatched transaction id");
da105ed5 1175 goto out;
991d9fa0
JT		 1176 }
1177
1178 pmd->trans_id = new_id;
da105ed5
JT		 1179 r = 0;
1180
1181out:
991d9fa0
JT		 1182 up_write(&pmd->root_lock);
1183
da105ed5 1184 return r;
991d9fa0
JT		 1185}
1186
1187int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1188 uint64_t *result)
1189{
da105ed5
JT		 1190 int r = -EINVAL;
1191
991d9fa0 1192 down_read(&pmd->root_lock);
da105ed5
JT		 1193 if (!pmd->fail_io) {
1194 *result = pmd->trans_id;
1195 r = 0;
1196 }
991d9fa0
JT		 1197 up_read(&pmd->root_lock);
1198
da105ed5 1199 return r;
991d9fa0
JT		 1200}
1201
cc8394d8
JT		 1202static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1203{
1204 int r, inc;
1205 struct thin_disk_superblock *disk_super;
1206 struct dm_block *copy, *sblock;
1207 dm_block_t held_root;
1208
49e99fc7
JT		 1209 /*
1210 * We commit to ensure the btree roots which we increment in a
1211 * moment are up to date.
1212 */
1213 __commit_transaction(pmd);
1214
cc8394d8
JT		 1215 /*
1216 * Copy the superblock.
1217 */
1218 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1219 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1220 &sb_validator, &copy, &inc);
1221 if (r)
1222 return r;
1223
1224 BUG_ON(!inc);
1225
1226 held_root = dm_block_location(copy);
1227 disk_super = dm_block_data(copy);
1228
1229 if (le64_to_cpu(disk_super->held_root)) {
1230 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1231
1232 dm_tm_dec(pmd->tm, held_root);
1233 dm_tm_unlock(pmd->tm, copy);
cc8394d8
JT		 1234 return -EBUSY;
1235 }
1236
1237 /*
1238 * Wipe the spacemap since we're not publishing this.
1239 */
1240 memset(&disk_super->data_space_map_root, 0,
1241 sizeof(disk_super->data_space_map_root));
1242 memset(&disk_super->metadata_space_map_root, 0,
1243 sizeof(disk_super->metadata_space_map_root));
1244
1245 /*
1246 * Increment the data structures that need to be preserved.
1247 */
1248 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1249 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1250 dm_tm_unlock(pmd->tm, copy);
1251
1252 /*
1253 * Write the held root into the superblock.
1254 */
25971192 1255 r = superblock_lock(pmd, &sblock);
cc8394d8
JT		 1256 if (r) {
1257 dm_tm_dec(pmd->tm, held_root);
cc8394d8
JT		 1258 return r;
1259 }
1260
1261 disk_super = dm_block_data(sblock);
1262 disk_super->held_root = cpu_to_le64(held_root);
1263 dm_bm_unlock(sblock);
cc8394d8
JT		 1264 return 0;
1265}
1266
1267int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1268{
da105ed5 1269 int r = -EINVAL;
cc8394d8
JT		 1270
1271 down_write(&pmd->root_lock);
da105ed5
JT		 1272 if (!pmd->fail_io)
1273 r = __reserve_metadata_snap(pmd);
cc8394d8
JT		 1274 up_write(&pmd->root_lock);
1275
1276 return r;
1277}
1278
1279static int __release_metadata_snap(struct dm_pool_metadata *pmd)
991d9fa0
JT		 1280{
1281 int r;
1282 struct thin_disk_superblock *disk_super;
cc8394d8
JT		 1283 struct dm_block *sblock, *copy;
1284 dm_block_t held_root;
991d9fa0 1285
25971192 1286 r = superblock_lock(pmd, &sblock);
991d9fa0
JT		 1287 if (r)
1288 return r;
1289
cc8394d8
JT		 1290 disk_super = dm_block_data(sblock);
1291 held_root = le64_to_cpu(disk_super->held_root);
1292 disk_super->held_root = cpu_to_le64(0);
cc8394d8
JT		 1293
1294 dm_bm_unlock(sblock);
1295
1296 if (!held_root) {
1297 DMWARN("No pool metadata snapshot found: nothing to release.");
1298 return -EINVAL;
1299 }
1300
1301 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
1302 if (r)
1303 return r;
1304
1305 disk_super = dm_block_data(copy);
7f518ad0
JT		 1306 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
1307 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
cc8394d8
JT		 1308 dm_sm_dec_block(pmd->metadata_sm, held_root);
1309
4c7da06f
MP		 1310 dm_tm_unlock(pmd->tm, copy);
1311
1312 return 0;
cc8394d8
JT		 1313}
1314
1315int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1316{
da105ed5 1317 int r = -EINVAL;
cc8394d8
JT		 1318
1319 down_write(&pmd->root_lock);
da105ed5
JT		 1320 if (!pmd->fail_io)
1321 r = __release_metadata_snap(pmd);
cc8394d8
JT		 1322 up_write(&pmd->root_lock);
1323
1324 return r;
1325}
1326
1327static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1328 dm_block_t *result)
1329{
1330 int r;
1331 struct thin_disk_superblock *disk_super;
1332 struct dm_block *sblock;
1333
1334 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1335 &sb_validator, &sblock);
1336 if (r)
1337 return r;
1338
991d9fa0
JT		 1339 disk_super = dm_block_data(sblock);
1340 *result = le64_to_cpu(disk_super->held_root);
1341
4c7da06f
MP		 1342 dm_bm_unlock(sblock);
1343
1344 return 0;
991d9fa0
JT		 1345}
1346
cc8394d8
JT		 1347int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1348 dm_block_t *result)
991d9fa0 1349{
da105ed5 1350 int r = -EINVAL;
991d9fa0
JT		 1351
1352 down_read(&pmd->root_lock);
da105ed5
JT		 1353 if (!pmd->fail_io)
1354 r = __get_metadata_snap(pmd, result);
991d9fa0
JT		 1355 up_read(&pmd->root_lock);
1356
1357 return r;
1358}
1359
1360int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1361 struct dm_thin_device **td)
1362{
da105ed5 1363 int r = -EINVAL;
991d9fa0
JT		 1364
1365 down_write(&pmd->root_lock);
da105ed5
JT		 1366 if (!pmd->fail_io)
1367 r = __open_device(pmd, dev, 0, td);
991d9fa0
JT		 1368 up_write(&pmd->root_lock);
1369
1370 return r;
1371}
1372
1373int dm_pool_close_thin_device(struct dm_thin_device *td)
1374{
1375 down_write(&td->pmd->root_lock);
1376 __close_device(td);
1377 up_write(&td->pmd->root_lock);
1378
1379 return 0;
1380}
1381
1382dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1383{
1384 return td->id;
1385}
1386
19fa1a67
JT		 1387/*
1388 * Check whether @time (of block creation) is older than @td's last snapshot.
1389 * If so then the associated block is shared with the last snapshot device.
1390 * Any block on a device created *after* the device last got snapshotted is
1391 * necessarily not shared.
1392 */
17b7d63f 1393static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
991d9fa0
JT		 1394{
1395 return td->snapshotted_time > time;
1396}
1397
3d5f6733
JT		 1398static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
1399 struct dm_thin_lookup_result *result)
1400{
1401 uint64_t block_time = 0;
1402 dm_block_t exception_block;
1403 uint32_t exception_time;
1404
1405 block_time = le64_to_cpu(value);
1406 unpack_block_time(block_time, &exception_block, &exception_time);
1407 result->block = exception_block;
1408 result->shared = __snapshotted_since(td, exception_time);
1409}
1410
086fbbbd
JT		 1411static int __find_block(struct dm_thin_device *td, dm_block_t block,
1412 int can_issue_io, struct dm_thin_lookup_result *result)
991d9fa0 1413{
e5cfc69a 1414 int r;
991d9fa0
JT		 1415 __le64 value;
1416 struct dm_pool_metadata *pmd = td->pmd;
1417 dm_block_t keys[2] = { td->id, block };
da105ed5 1418 struct dm_btree_info *info;
991d9fa0 1419
e5cfc69a
JT		 1420 if (can_issue_io) {
1421 info = &pmd->info;
1422 } else
1423 info = &pmd->nb_info;
da105ed5 1424
e5cfc69a 1425 r = dm_btree_lookup(info, pmd->root, keys, &value);
3d5f6733
JT		 1426 if (!r)
1427 unpack_lookup_result(td, value, result);
1428
3d5f6733
JT		 1429 return r;
1430}
1431
086fbbbd
JT		 1432int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1433 int can_issue_io, struct dm_thin_lookup_result *result)
3d5f6733
JT		 1434{
1435 int r;
3d5f6733 1436 struct dm_pool_metadata *pmd = td->pmd;
3d5f6733
JT		 1437
1438 down_read(&pmd->root_lock);
1439 if (pmd->fail_io) {
1440 up_read(&pmd->root_lock);
1441 return -EINVAL;
991d9fa0
JT		 1442 }
1443
086fbbbd
JT		 1444 r = __find_block(td, block, can_issue_io, result);
1445
1446 up_read(&pmd->root_lock);
1447 return r;
1448}
1449
1450static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
1451 dm_block_t *vblock,
1452 struct dm_thin_lookup_result *result)
1453{
1454 int r;
1455 __le64 value;
1456 struct dm_pool_metadata *pmd = td->pmd;
1457 dm_block_t keys[2] = { td->id, block };
1458
3d5f6733
JT		 1459 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1460 if (!r)
1461 unpack_lookup_result(td, value, result);
1462
991d9fa0
JT		 1463 return r;
1464}
1465
086fbbbd
JT		 1466static int __find_mapped_range(struct dm_thin_device *td,
1467 dm_block_t begin, dm_block_t end,
1468 dm_block_t *thin_begin, dm_block_t *thin_end,
1469 dm_block_t *pool_begin, bool *maybe_shared)
a5d895a9
JT		 1470{
1471 int r;
1472 dm_block_t pool_end;
1473 struct dm_thin_lookup_result lookup;
1474
1475 if (end < begin)
1476 return -ENODATA;
1477
086fbbbd 1478 r = __find_next_mapped_block(td, begin, &begin, &lookup);
3d5f6733
JT		 1479 if (r)
1480 return r;
a5d895a9 1481
3d5f6733 1482 if (begin >= end)
a5d895a9
JT		 1483 return -ENODATA;
1484
1485 *thin_begin = begin;
1486 *pool_begin = lookup.block;
1487 *maybe_shared = lookup.shared;
1488
1489 begin++;
1490 pool_end = *pool_begin + 1;
1491 while (begin != end) {
086fbbbd 1492 r = __find_block(td, begin, true, &lookup);
a5d895a9
JT		 1493 if (r) {
1494 if (r == -ENODATA)
1495 break;
1496 else
1497 return r;
1498 }
1499
1500 if ((lookup.block != pool_end) ||
1501 (lookup.shared != *maybe_shared))
1502 break;
1503
1504 pool_end++;
1505 begin++;
1506 }
1507
1508 *thin_end = begin;
1509 return 0;
1510}
1511
086fbbbd
JT		 1512int dm_thin_find_mapped_range(struct dm_thin_device *td,
1513 dm_block_t begin, dm_block_t end,
1514 dm_block_t *thin_begin, dm_block_t *thin_end,
1515 dm_block_t *pool_begin, bool *maybe_shared)
1516{
1517 int r = -EINVAL;
1518 struct dm_pool_metadata *pmd = td->pmd;
1519
1520 down_read(&pmd->root_lock);
1521 if (!pmd->fail_io) {
1522 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
1523 pool_begin, maybe_shared);
1524 }
1525 up_read(&pmd->root_lock);
1526
1527 return r;
1528}
1529
991d9fa0
JT		 1530static int __insert(struct dm_thin_device *td, dm_block_t block,
1531 dm_block_t data_block)
1532{
1533 int r, inserted;
1534 __le64 value;
1535 struct dm_pool_metadata *pmd = td->pmd;
1536 dm_block_t keys[2] = { td->id, block };
1537
991d9fa0
JT		 1538 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1539 __dm_bless_for_disk(&value);
1540
1541 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1542 &pmd->root, &inserted);
1543 if (r)
1544 return r;
1545
40db5a53
JT		 1546 td->changed = 1;
1547 if (inserted)
991d9fa0 1548 td->mapped_blocks++;
991d9fa0
JT		 1549
1550 return 0;
1551}
1552
1553int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1554 dm_block_t data_block)
1555{
da105ed5 1556 int r = -EINVAL;
991d9fa0
JT		 1557
1558 down_write(&td->pmd->root_lock);
da105ed5
JT		 1559 if (!td->pmd->fail_io)
1560 r = __insert(td, block, data_block);
991d9fa0
JT		 1561 up_write(&td->pmd->root_lock);
1562
1563 return r;
1564}
1565
1566static int __remove(struct dm_thin_device *td, dm_block_t block)
1567{
1568 int r;
1569 struct dm_pool_metadata *pmd = td->pmd;
1570 dm_block_t keys[2] = { td->id, block };
1571
1572 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1573 if (r)
1574 return r;
1575
af63bcb8
JT		 1576 td->mapped_blocks--;
1577 td->changed = 1;
991d9fa0
JT		 1578
1579 return 0;
1580}
1581
6550f075
JT		 1582static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1583{
1584 int r;
993ceab9 1585 unsigned count, total_count = 0;
6550f075
JT		 1586 struct dm_pool_metadata *pmd = td->pmd;
1587 dm_block_t keys[1] = { td->id };
1588 __le64 value;
1589 dm_block_t mapping_root;
1590
1591 /*
1592 * Find the mapping tree
1593 */
1594 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
1595 if (r)
1596 return r;
1597
1598 /*
1599 * Remove from the mapping tree, taking care to inc the
1600 * ref count so it doesn't get deleted.
1601 */
1602 mapping_root = le64_to_cpu(value);
1603 dm_tm_inc(pmd->tm, mapping_root);
1604 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
1605 if (r)
1606 return r;
1607
993ceab9
JT		 1608 /*
1609 * Remove leaves stops at the first unmapped entry, so we have to
1610 * loop round finding mapped ranges.
1611 */
1612 while (begin < end) {
1613 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
1614 if (r == -ENODATA)
1615 break;
1616
1617 if (r)
1618 return r;
1619
1620 if (begin >= end)
1621 break;
1622
1623 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
1624 if (r)
1625 return r;
1626
1627 total_count += count;
1628 }
6550f075 1629
993ceab9 1630 td->mapped_blocks -= total_count;
6550f075
JT		 1631 td->changed = 1;
1632
1633 /*
1634 * Reinsert the mapping tree.
1635 */
1636 value = cpu_to_le64(mapping_root);
1637 __dm_bless_for_disk(&value);
1638 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
1639}
1640
991d9fa0
JT		 1641int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1642{
da105ed5 1643 int r = -EINVAL;
991d9fa0
JT		 1644
1645 down_write(&td->pmd->root_lock);
da105ed5
JT		 1646 if (!td->pmd->fail_io)
1647 r = __remove(td, block);
991d9fa0 1648 up_write(&td->pmd->root_lock);
19fa1a67
JT		 1649
1650 return r;
1651}
1652
6550f075
JT		 1653int dm_thin_remove_range(struct dm_thin_device *td,
1654 dm_block_t begin, dm_block_t end)
1655{
1656 int r = -EINVAL;
1657
1658 down_write(&td->pmd->root_lock);
1659 if (!td->pmd->fail_io)
1660 r = __remove_range(td, begin, end);
1661 up_write(&td->pmd->root_lock);
1662
1663 return r;
1664}
1665
19fa1a67
JT		 1666int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
1667{
1668 int r;
1669 uint32_t ref_count;
1670
1671 down_read(&pmd->root_lock);
1672 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
1673 if (!r)
1674 *result = (ref_count != 0);
1675 up_read(&pmd->root_lock);
991d9fa0
JT		 1676
1677 return r;
1678}
1679
40db5a53
JT		 1680bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1681{
1682 int r;
1683
1684 down_read(&td->pmd->root_lock);
1685 r = td->changed;
1686 up_read(&td->pmd->root_lock);
1687
1688 return r;
1689}
1690
4d1662a3
MS		 1691bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
1692{
1693 bool r = false;
1694 struct dm_thin_device *td, *tmp;
1695
1696 down_read(&pmd->root_lock);
1697 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1698 if (td->changed) {
1699 r = td->changed;
1700 break;
1701 }
1702 }
1703 up_read(&pmd->root_lock);
1704
1705 return r;
1706}
1707
da105ed5
JT		 1708bool dm_thin_aborted_changes(struct dm_thin_device *td)
1709{
1710 bool r;
1711
1712 down_read(&td->pmd->root_lock);
1713 r = td->aborted_with_changes;
1714 up_read(&td->pmd->root_lock);
1715
1716 return r;
1717}
1718
991d9fa0
JT		 1719int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1720{
da105ed5 1721 int r = -EINVAL;
991d9fa0
JT		 1722
1723 down_write(&pmd->root_lock);
da105ed5
JT		 1724 if (!pmd->fail_io)
1725 r = dm_sm_new_block(pmd->data_sm, result);
991d9fa0
JT		 1726 up_write(&pmd->root_lock);
1727
1728 return r;
1729}
1730
1731int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1732{
da105ed5 1733 int r = -EINVAL;
991d9fa0
JT		 1734
1735 down_write(&pmd->root_lock);
da105ed5
JT		 1736 if (pmd->fail_io)
1737 goto out;
991d9fa0
JT		 1738
1739 r = __commit_transaction(pmd);
1740 if (r <= 0)
1741 goto out;
1742
1743 /*
1744 * Open the next transaction.
1745 */
1746 r = __begin_transaction(pmd);
1747out:
1748 up_write(&pmd->root_lock);
1749 return r;
1750}
1751
da105ed5
JT		 1752static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1753{
1754 struct dm_thin_device *td;
1755
1756 list_for_each_entry(td, &pmd->thin_devices, list)
1757 td->aborted_with_changes = td->changed;
1758}
1759
1760int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1761{
1762 int r = -EINVAL;
1763
1764 down_write(&pmd->root_lock);
1765 if (pmd->fail_io)
1766 goto out;
1767
1768 __set_abort_with_changes_flags(pmd);
1769 __destroy_persistent_data_objects(pmd);
1770 r = __create_persistent_data_objects(pmd, false);
1771 if (r)
1772 pmd->fail_io = true;
1773
1774out:
1775 up_write(&pmd->root_lock);
1776
1777 return r;
1778}
1779
991d9fa0
JT		 1780int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1781{
da105ed5 1782 int r = -EINVAL;
991d9fa0
JT		 1783
1784 down_read(&pmd->root_lock);
da105ed5
JT		 1785 if (!pmd->fail_io)
1786 r = dm_sm_get_nr_free(pmd->data_sm, result);
991d9fa0
JT		 1787 up_read(&pmd->root_lock);
1788
1789 return r;
1790}
1791
1792int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1793 dm_block_t *result)
1794{
da105ed5 1795 int r = -EINVAL;
991d9fa0
JT		 1796
1797 down_read(&pmd->root_lock);
da105ed5
JT		 1798 if (!pmd->fail_io)
1799 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
991d9fa0
JT		 1800 up_read(&pmd->root_lock);
1801
1802 return r;
1803}
1804
1805int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1806 dm_block_t *result)
1807{
da105ed5 1808 int r = -EINVAL;
991d9fa0
JT		 1809
1810 down_read(&pmd->root_lock);
da105ed5
JT		 1811 if (!pmd->fail_io)
1812 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
991d9fa0
JT		 1813 up_read(&pmd->root_lock);
1814
1815 return r;
1816}
1817
991d9fa0
JT		 1818int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1819{
da105ed5 1820 int r = -EINVAL;
991d9fa0
JT		 1821
1822 down_read(&pmd->root_lock);
da105ed5
JT		 1823 if (!pmd->fail_io)
1824 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
991d9fa0
JT		 1825 up_read(&pmd->root_lock);
1826
1827 return r;
1828}
1829
1830int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1831{
da105ed5 1832 int r = -EINVAL;
991d9fa0
JT		 1833 struct dm_pool_metadata *pmd = td->pmd;
1834
1835 down_read(&pmd->root_lock);
da105ed5
JT		 1836 if (!pmd->fail_io) {
1837 *result = td->mapped_blocks;
1838 r = 0;
1839 }
991d9fa0
JT		 1840 up_read(&pmd->root_lock);
1841
da105ed5 1842 return r;
991d9fa0
JT		 1843}
1844
1845static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1846{
1847 int r;
1848 __le64 value_le;
1849 dm_block_t thin_root;
1850 struct dm_pool_metadata *pmd = td->pmd;
1851
1852 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1853 if (r)
1854 return r;
1855
1856 thin_root = le64_to_cpu(value_le);
1857
1858 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1859}
1860
1861int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1862 dm_block_t *result)
1863{
da105ed5 1864 int r = -EINVAL;
991d9fa0
JT		 1865 struct dm_pool_metadata *pmd = td->pmd;
1866
1867 down_read(&pmd->root_lock);
da105ed5
JT		 1868 if (!pmd->fail_io)
1869 r = __highest_block(td, result);
991d9fa0
JT		 1870 up_read(&pmd->root_lock);
1871
1872 return r;
1873}
1874
b17446df 1875static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
991d9fa0
JT		 1876{
1877 int r;
1878 dm_block_t old_count;
1879
b17446df 1880 r = dm_sm_get_nr_blocks(sm, &old_count);
991d9fa0
JT		 1881 if (r)
1882 return r;
1883
1884 if (new_count == old_count)
1885 return 0;
1886
1887 if (new_count < old_count) {
b17446df 1888 DMERR("cannot reduce size of space map");
991d9fa0
JT		 1889 return -EINVAL;
1890 }
1891
b17446df 1892 return dm_sm_extend(sm, new_count - old_count);
991d9fa0
JT		 1893}
1894
1895int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1896{
da105ed5 1897 int r = -EINVAL;
991d9fa0
JT		 1898
1899 down_write(&pmd->root_lock);
da105ed5 1900 if (!pmd->fail_io)
b17446df 1901 r = __resize_space_map(pmd->data_sm, new_count);
991d9fa0
JT		 1902 up_write(&pmd->root_lock);
1903
1904 return r;
1905}
12ba58af 1906
24347e95
JT		 1907int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1908{
1909 int r = -EINVAL;
1910
1911 down_write(&pmd->root_lock);
1912 if (!pmd->fail_io)
1913 r = __resize_space_map(pmd->metadata_sm, new_count);
1914 up_write(&pmd->root_lock);
1915
1916 return r;
1917}
1918
12ba58af
JT		 1919void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1920{
1921 down_write(&pmd->root_lock);
12ba58af
JT		 1922 dm_bm_set_read_only(pmd->bm);
1923 up_write(&pmd->root_lock);
1924}
ac8c3f3d 1925
9b7aaa64
JT		 1926void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
1927{
1928 down_write(&pmd->root_lock);
9b7aaa64
JT		 1929 dm_bm_set_read_write(pmd->bm);
1930 up_write(&pmd->root_lock);
1931}
1932
ac8c3f3d
JT		 1933int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
1934 dm_block_t threshold,
1935 dm_sm_threshold_fn fn,
1936 void *context)
1937{
1938 int r;
1939
1940 down_write(&pmd->root_lock);
1941 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
1942 up_write(&pmd->root_lock);
1943
1944 return r;
1945}
07f2b6e0
MS		 1946
1947int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
1948{
1949 int r;
1950 struct dm_block *sblock;
1951 struct thin_disk_superblock *disk_super;
1952
1953 down_write(&pmd->root_lock);
1954 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
1955
1956 r = superblock_lock(pmd, &sblock);
1957 if (r) {
1958 DMERR("couldn't read superblock");
1959 goto out;
1960 }
1961
1962 disk_super = dm_block_data(sblock);
1963 disk_super->flags = cpu_to_le32(pmd->flags);
1964
1965 dm_bm_unlock(sblock);
1966out:
1967 up_write(&pmd->root_lock);
1968 return r;
1969}
1970
1971bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
1972{
1973 bool needs_check;
1974
1975 down_read(&pmd->root_lock);
1976 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
1977 up_read(&pmd->root_lock);
1978
1979 return needs_check;
1980}
8a01a6af
JT		 1981
1982void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
1983{
2eae9e44
JT		 1984 down_read(&pmd->root_lock);
1985 if (!pmd->fail_io)
1986 dm_tm_issue_prefetches(pmd->tm);
1987 up_read(&pmd->root_lock);
8a01a6af 1988}
Linux 6.x block layer and io_uring tree(s)