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[mirror_ubuntu-artful-kernel.git] / drivers / md / dm-thin-metadata.c
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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 SECTOR_TO_BLOCK_SHIFT 3
81
8c971178
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82/*
83 * 3 for btree insert +
84 * 2 for btree lookup used within space map
85 */
86#define THIN_MAX_CONCURRENT_LOCKS 5
87
991d9fa0
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88/* This should be plenty */
89#define SPACE_MAP_ROOT_SIZE 128
90
91/*
92 * Little endian on-disk superblock and device details.
93 */
94struct thin_disk_superblock {
95 __le32 csum; /* Checksum of superblock except for this field. */
96 __le32 flags;
97 __le64 blocknr; /* This block number, dm_block_t. */
98
99 __u8 uuid[16];
100 __le64 magic;
101 __le32 version;
102 __le32 time;
103
104 __le64 trans_id;
105
106 /*
107 * Root held by userspace transactions.
108 */
109 __le64 held_root;
110
111 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
112 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
113
114 /*
115 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
116 */
117 __le64 data_mapping_root;
118
119 /*
120 * Device detail root mapping dev_id -> device_details
121 */
122 __le64 device_details_root;
123
124 __le32 data_block_size; /* In 512-byte sectors. */
125
126 __le32 metadata_block_size; /* In 512-byte sectors. */
127 __le64 metadata_nr_blocks;
128
129 __le32 compat_flags;
130 __le32 compat_ro_flags;
131 __le32 incompat_flags;
132} __packed;
133
134struct disk_device_details {
135 __le64 mapped_blocks;
136 __le64 transaction_id; /* When created. */
137 __le32 creation_time;
138 __le32 snapshotted_time;
139} __packed;
140
141struct dm_pool_metadata {
142 struct hlist_node hash;
143
144 struct block_device *bdev;
145 struct dm_block_manager *bm;
146 struct dm_space_map *metadata_sm;
147 struct dm_space_map *data_sm;
148 struct dm_transaction_manager *tm;
149 struct dm_transaction_manager *nb_tm;
150
151 /*
152 * Two-level btree.
153 * First level holds thin_dev_t.
154 * Second level holds mappings.
155 */
156 struct dm_btree_info info;
157
158 /*
159 * Non-blocking version of the above.
160 */
161 struct dm_btree_info nb_info;
162
163 /*
164 * Just the top level for deleting whole devices.
165 */
166 struct dm_btree_info tl_info;
167
168 /*
169 * Just the bottom level for creating new devices.
170 */
171 struct dm_btree_info bl_info;
172
173 /*
174 * Describes the device details btree.
175 */
176 struct dm_btree_info details_info;
177
178 struct rw_semaphore root_lock;
179 uint32_t time;
991d9fa0
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180 dm_block_t root;
181 dm_block_t details_root;
182 struct list_head thin_devices;
183 uint64_t trans_id;
184 unsigned long flags;
185 sector_t data_block_size;
da105ed5
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186
187 /*
188 * Set if a transaction has to be aborted but the attempt to roll back
189 * to the previous (good) transaction failed. The only pool metadata
190 * operation possible in this state is the closing of the device.
191 */
192 bool fail_io:1;
5a32083d
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193
194 /*
195 * Reading the space map roots can fail, so we read it into these
196 * buffers before the superblock is locked and updated.
197 */
198 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
199 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
991d9fa0
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200};
201
202struct dm_thin_device {
203 struct list_head list;
204 struct dm_pool_metadata *pmd;
205 dm_thin_id id;
206
207 int open_count;
da105ed5
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208 bool changed:1;
209 bool aborted_with_changes:1;
991d9fa0
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210 uint64_t mapped_blocks;
211 uint64_t transaction_id;
212 uint32_t creation_time;
213 uint32_t snapshotted_time;
214};
215
216/*----------------------------------------------------------------
217 * superblock validator
218 *--------------------------------------------------------------*/
219
220#define SUPERBLOCK_CSUM_XOR 160774
221
222static void sb_prepare_for_write(struct dm_block_validator *v,
223 struct dm_block *b,
224 size_t block_size)
225{
226 struct thin_disk_superblock *disk_super = dm_block_data(b);
227
228 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
229 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
230 block_size - sizeof(__le32),
231 SUPERBLOCK_CSUM_XOR));
232}
233
234static int sb_check(struct dm_block_validator *v,
235 struct dm_block *b,
236 size_t block_size)
237{
238 struct thin_disk_superblock *disk_super = dm_block_data(b);
239 __le32 csum_le;
240
241 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
242 DMERR("sb_check failed: blocknr %llu: "
243 "wanted %llu", le64_to_cpu(disk_super->blocknr),
244 (unsigned long long)dm_block_location(b));
245 return -ENOTBLK;
246 }
247
248 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
249 DMERR("sb_check failed: magic %llu: "
250 "wanted %llu", le64_to_cpu(disk_super->magic),
251 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
252 return -EILSEQ;
253 }
254
255 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
256 block_size - sizeof(__le32),
257 SUPERBLOCK_CSUM_XOR));
258 if (csum_le != disk_super->csum) {
259 DMERR("sb_check failed: csum %u: wanted %u",
260 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
261 return -EILSEQ;
262 }
263
264 return 0;
265}
266
267static struct dm_block_validator sb_validator = {
268 .name = "superblock",
269 .prepare_for_write = sb_prepare_for_write,
270 .check = sb_check
271};
272
273/*----------------------------------------------------------------
274 * Methods for the btree value types
275 *--------------------------------------------------------------*/
276
277static uint64_t pack_block_time(dm_block_t b, uint32_t t)
278{
279 return (b << 24) | t;
280}
281
282static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
283{
284 *b = v >> 24;
285 *t = v & ((1 << 24) - 1);
286}
287
018cede9 288static void data_block_inc(void *context, const void *value_le)
991d9fa0
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289{
290 struct dm_space_map *sm = context;
291 __le64 v_le;
292 uint64_t b;
293 uint32_t t;
294
295 memcpy(&v_le, value_le, sizeof(v_le));
296 unpack_block_time(le64_to_cpu(v_le), &b, &t);
297 dm_sm_inc_block(sm, b);
298}
299
018cede9 300static void data_block_dec(void *context, const void *value_le)
991d9fa0
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301{
302 struct dm_space_map *sm = context;
303 __le64 v_le;
304 uint64_t b;
305 uint32_t t;
306
307 memcpy(&v_le, value_le, sizeof(v_le));
308 unpack_block_time(le64_to_cpu(v_le), &b, &t);
309 dm_sm_dec_block(sm, b);
310}
311
018cede9 312static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
991d9fa0
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313{
314 __le64 v1_le, v2_le;
315 uint64_t b1, b2;
316 uint32_t t;
317
318 memcpy(&v1_le, value1_le, sizeof(v1_le));
319 memcpy(&v2_le, value2_le, sizeof(v2_le));
320 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
321 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
322
323 return b1 == b2;
324}
325
018cede9 326static void subtree_inc(void *context, const void *value)
991d9fa0
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327{
328 struct dm_btree_info *info = context;
329 __le64 root_le;
330 uint64_t root;
331
332 memcpy(&root_le, value, sizeof(root_le));
333 root = le64_to_cpu(root_le);
334 dm_tm_inc(info->tm, root);
335}
336
018cede9 337static void subtree_dec(void *context, const void *value)
991d9fa0
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338{
339 struct dm_btree_info *info = context;
340 __le64 root_le;
341 uint64_t root;
342
343 memcpy(&root_le, value, sizeof(root_le));
344 root = le64_to_cpu(root_le);
345 if (dm_btree_del(info, root))
29f929b5 346 DMERR("btree delete failed");
991d9fa0
JT
347}
348
018cede9 349static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
991d9fa0
JT
350{
351 __le64 v1_le, v2_le;
352 memcpy(&v1_le, value1_le, sizeof(v1_le));
353 memcpy(&v2_le, value2_le, sizeof(v2_le));
354
355 return v1_le == v2_le;
356}
357
358/*----------------------------------------------------------------*/
359
25971192
JT
360static int superblock_lock_zero(struct dm_pool_metadata *pmd,
361 struct dm_block **sblock)
362{
363 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
364 &sb_validator, sblock);
365}
366
367static int superblock_lock(struct dm_pool_metadata *pmd,
368 struct dm_block **sblock)
369{
370 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
371 &sb_validator, sblock);
372}
373
332627db 374static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
991d9fa0
JT
375{
376 int r;
377 unsigned i;
378 struct dm_block *b;
379 __le64 *data_le, zero = cpu_to_le64(0);
380 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
381
382 /*
383 * We can't use a validator here - it may be all zeroes.
384 */
385 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
386 if (r)
387 return r;
388
389 data_le = dm_block_data(b);
390 *result = 1;
391 for (i = 0; i < block_size; i++) {
392 if (data_le[i] != zero) {
393 *result = 0;
394 break;
395 }
396 }
397
4c7da06f
MP
398 dm_bm_unlock(b);
399
400 return 0;
991d9fa0
JT
401}
402
41675aea
JT
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;
e3cbf945 418 pmd->tl_info.value_type.context = &pmd->bl_info;
41675aea
JT
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
5a32083d
JT
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
9cb6653f
JT
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
5a32083d 483 r = dm_sm_commit(pmd->data_sm);
10d2a9ff
JT
484 if (r < 0)
485 return r;
486
91bcdb92 487 r = dm_tm_pre_commit(pmd->tm);
10d2a9ff
JT
488 if (r < 0)
489 return r;
490
91bcdb92 491 r = save_sm_roots(pmd);
10d2a9ff
JT
492 if (r < 0)
493 return r;
494
9cb6653f
JT
495 r = superblock_lock_zero(pmd, &sblock);
496 if (r)
497 return r;
498
499 disk_super = dm_block_data(sblock);
10d2a9ff 500 disk_super->flags = 0;
583ceee2 501 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
9cb6653f
JT
502 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
503 disk_super->version = cpu_to_le32(THIN_VERSION);
504 disk_super->time = 0;
10d2a9ff
JT
505 disk_super->trans_id = 0;
506 disk_super->held_root = 0;
507
5a32083d 508 copy_sm_roots(pmd, disk_super);
10d2a9ff
JT
509
510 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
511 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
7d48935e 512 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
9cb6653f
JT
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
270938ba 516 return dm_tm_commit(pmd->tm, sblock);
9cb6653f
JT
517}
518
a97e5e6f 519static int __format_metadata(struct dm_pool_metadata *pmd)
991d9fa0
JT
520{
521 int r;
384ef0e6 522
e4d2205c
JT
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 }
991d9fa0 529
a97e5e6f 530 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
e4d2205c
JT
531 if (IS_ERR(pmd->data_sm)) {
532 DMERR("sm_disk_create failed");
533 r = PTR_ERR(pmd->data_sm);
0fa5b17b 534 goto bad_cleanup_tm;
991d9fa0
JT
535 }
536
d6332814 537 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
991d9fa0 538 if (!pmd->nb_tm) {
0fa5b17b 539 DMERR("could not create non-blocking clone tm");
991d9fa0 540 r = -ENOMEM;
0fa5b17b 541 goto bad_cleanup_data_sm;
991d9fa0
JT
542 }
543
41675aea 544 __setup_btree_details(pmd);
991d9fa0 545
9cb6653f
JT
546 r = dm_btree_empty(&pmd->info, &pmd->root);
547 if (r < 0)
0fa5b17b 548 goto bad_cleanup_nb_tm;
9cb6653f
JT
549
550 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
551 if (r < 0) {
552 DMERR("couldn't create devices root");
0fa5b17b 553 goto bad_cleanup_nb_tm;
9cb6653f
JT
554 }
555
556 r = __write_initial_superblock(pmd);
557 if (r)
0fa5b17b 558 goto bad_cleanup_nb_tm;
9cb6653f 559
991d9fa0
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560 return 0;
561
0fa5b17b
JT
562bad_cleanup_nb_tm:
563 dm_tm_destroy(pmd->nb_tm);
564bad_cleanup_data_sm:
d6332814 565 dm_sm_destroy(pmd->data_sm);
0fa5b17b 566bad_cleanup_tm:
d6332814
JT
567 dm_tm_destroy(pmd->tm);
568 dm_sm_destroy(pmd->metadata_sm);
991d9fa0
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569
570 return r;
571}
572
d73ec525
MS
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
e4d2205c
JT
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);
d73ec525 615
9aec8629
MS
616 /* Verify the data block size hasn't changed */
617 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
618 DMERR("changing the data block size (from %u to %llu) is not supported",
619 le32_to_cpu(disk_super->data_block_size),
620 (unsigned long long)pmd->data_block_size);
621 r = -EINVAL;
622 goto bad_unlock_sblock;
623 }
624
d73ec525 625 r = __check_incompat_features(disk_super, pmd);
0fa5b17b
JT
626 if (r < 0)
627 goto bad_unlock_sblock;
d73ec525 628
e4d2205c
JT
629 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
630 disk_super->metadata_space_map_root,
631 sizeof(disk_super->metadata_space_map_root),
632 &pmd->tm, &pmd->metadata_sm);
633 if (r < 0) {
634 DMERR("tm_open_with_sm failed");
0fa5b17b 635 goto bad_unlock_sblock;
e4d2205c
JT
636 }
637
638 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
639 sizeof(disk_super->data_space_map_root));
640 if (IS_ERR(pmd->data_sm)) {
641 DMERR("sm_disk_open failed");
e4d2205c 642 r = PTR_ERR(pmd->data_sm);
0fa5b17b 643 goto bad_cleanup_tm;
e4d2205c
JT
644 }
645
e4d2205c
JT
646 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
647 if (!pmd->nb_tm) {
0fa5b17b 648 DMERR("could not create non-blocking clone tm");
e4d2205c 649 r = -ENOMEM;
0fa5b17b 650 goto bad_cleanup_data_sm;
e4d2205c
JT
651 }
652
653 __setup_btree_details(pmd);
4c7da06f
MP
654 dm_bm_unlock(sblock);
655
656 return 0;
e4d2205c 657
0fa5b17b 658bad_cleanup_data_sm:
e4d2205c 659 dm_sm_destroy(pmd->data_sm);
0fa5b17b 660bad_cleanup_tm:
e4d2205c
JT
661 dm_tm_destroy(pmd->tm);
662 dm_sm_destroy(pmd->metadata_sm);
0fa5b17b
JT
663bad_unlock_sblock:
664 dm_bm_unlock(sblock);
e4d2205c
JT
665
666 return r;
667}
668
66b1edc0 669static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
e4d2205c 670{
8801e069 671 int r, unformatted;
237074c0 672
8801e069 673 r = __superblock_all_zeroes(pmd->bm, &unformatted);
237074c0
JT
674 if (r)
675 return r;
676
8801e069 677 if (unformatted)
66b1edc0
JT
678 return format_device ? __format_metadata(pmd) : -EPERM;
679
680 return __open_metadata(pmd);
e4d2205c
JT
681}
682
66b1edc0 683static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
332627db
JT
684{
685 int r;
686
7d48935e 687 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
332627db
JT
688 THIN_MAX_CONCURRENT_LOCKS);
689 if (IS_ERR(pmd->bm)) {
690 DMERR("could not create block manager");
691 return PTR_ERR(pmd->bm);
692 }
693
66b1edc0 694 r = __open_or_format_metadata(pmd, format_device);
332627db
JT
695 if (r)
696 dm_block_manager_destroy(pmd->bm);
697
698 return r;
699}
700
f9dd9352
JT
701static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
702{
703 dm_sm_destroy(pmd->data_sm);
704 dm_sm_destroy(pmd->metadata_sm);
705 dm_tm_destroy(pmd->nb_tm);
706 dm_tm_destroy(pmd->tm);
707 dm_block_manager_destroy(pmd->bm);
708}
709
991d9fa0
JT
710static int __begin_transaction(struct dm_pool_metadata *pmd)
711{
712 int r;
991d9fa0
JT
713 struct thin_disk_superblock *disk_super;
714 struct dm_block *sblock;
715
991d9fa0
JT
716 /*
717 * We re-read the superblock every time. Shouldn't need to do this
718 * really.
719 */
720 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
721 &sb_validator, &sblock);
722 if (r)
723 return r;
724
725 disk_super = dm_block_data(sblock);
726 pmd->time = le32_to_cpu(disk_super->time);
727 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
728 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
729 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
730 pmd->flags = le32_to_cpu(disk_super->flags);
731 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
732
991d9fa0 733 dm_bm_unlock(sblock);
d73ec525 734 return 0;
991d9fa0
JT
735}
736
737static int __write_changed_details(struct dm_pool_metadata *pmd)
738{
739 int r;
740 struct dm_thin_device *td, *tmp;
741 struct disk_device_details details;
742 uint64_t key;
743
744 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
745 if (!td->changed)
746 continue;
747
748 key = td->id;
749
750 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
751 details.transaction_id = cpu_to_le64(td->transaction_id);
752 details.creation_time = cpu_to_le32(td->creation_time);
753 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
754 __dm_bless_for_disk(&details);
755
756 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
757 &key, &details, &pmd->details_root);
758 if (r)
759 return r;
760
761 if (td->open_count)
762 td->changed = 0;
763 else {
764 list_del(&td->list);
765 kfree(td);
766 }
991d9fa0
JT
767 }
768
769 return 0;
770}
771
772static int __commit_transaction(struct dm_pool_metadata *pmd)
773{
991d9fa0
JT
774 int r;
775 size_t metadata_len, data_len;
776 struct thin_disk_superblock *disk_super;
777 struct dm_block *sblock;
778
779 /*
780 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
781 */
782 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
783
784 r = __write_changed_details(pmd);
785 if (r < 0)
d973ac19 786 return r;
991d9fa0 787
991d9fa0
JT
788 r = dm_sm_commit(pmd->data_sm);
789 if (r < 0)
d973ac19 790 return r;
991d9fa0
JT
791
792 r = dm_tm_pre_commit(pmd->tm);
793 if (r < 0)
d973ac19 794 return r;
991d9fa0
JT
795
796 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
797 if (r < 0)
d973ac19 798 return r;
991d9fa0 799
fef838cc 800 r = dm_sm_root_size(pmd->data_sm, &data_len);
991d9fa0 801 if (r < 0)
d973ac19 802 return r;
991d9fa0 803
5a32083d
JT
804 r = save_sm_roots(pmd);
805 if (r < 0)
806 return r;
807
25971192 808 r = superblock_lock(pmd, &sblock);
991d9fa0 809 if (r)
d973ac19 810 return r;
991d9fa0
JT
811
812 disk_super = dm_block_data(sblock);
813 disk_super->time = cpu_to_le32(pmd->time);
814 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
815 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
816 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
817 disk_super->flags = cpu_to_le32(pmd->flags);
818
5a32083d 819 copy_sm_roots(pmd, disk_super);
991d9fa0 820
eb04cf63 821 return dm_tm_commit(pmd->tm, sblock);
991d9fa0
JT
822}
823
824struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
66b1edc0
JT
825 sector_t data_block_size,
826 bool format_device)
991d9fa0
JT
827{
828 int r;
991d9fa0 829 struct dm_pool_metadata *pmd;
991d9fa0
JT
830
831 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
832 if (!pmd) {
833 DMERR("could not allocate metadata struct");
834 return ERR_PTR(-ENOMEM);
835 }
836
6a0ebd31
JT
837 init_rwsem(&pmd->root_lock);
838 pmd->time = 0;
839 INIT_LIST_HEAD(&pmd->thin_devices);
da105ed5 840 pmd->fail_io = false;
332627db 841 pmd->bdev = bdev;
9cb6653f 842 pmd->data_block_size = data_block_size;
991d9fa0 843
66b1edc0 844 r = __create_persistent_data_objects(pmd, format_device);
991d9fa0 845 if (r) {
991d9fa0
JT
846 kfree(pmd);
847 return ERR_PTR(r);
848 }
991d9fa0 849
270938ba
JT
850 r = __begin_transaction(pmd);
851 if (r < 0) {
852 if (dm_pool_metadata_close(pmd) < 0)
853 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
854 return ERR_PTR(r);
991d9fa0
JT
855 }
856
857 return pmd;
991d9fa0
JT
858}
859
860int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
861{
862 int r;
863 unsigned open_devices = 0;
864 struct dm_thin_device *td, *tmp;
865
866 down_read(&pmd->root_lock);
867 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
868 if (td->open_count)
869 open_devices++;
870 else {
871 list_del(&td->list);
872 kfree(td);
873 }
874 }
875 up_read(&pmd->root_lock);
876
877 if (open_devices) {
878 DMERR("attempt to close pmd when %u device(s) are still open",
879 open_devices);
880 return -EBUSY;
881 }
882
49f154c7 883 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
12ba58af
JT
884 r = __commit_transaction(pmd);
885 if (r < 0)
886 DMWARN("%s: __commit_transaction() failed, error = %d",
887 __func__, r);
888 }
991d9fa0 889
da105ed5
JT
890 if (!pmd->fail_io)
891 __destroy_persistent_data_objects(pmd);
991d9fa0 892
da105ed5 893 kfree(pmd);
991d9fa0
JT
894 return 0;
895}
896
1f3db25d
MS
897/*
898 * __open_device: Returns @td corresponding to device with id @dev,
899 * creating it if @create is set and incrementing @td->open_count.
900 * On failure, @td is undefined.
901 */
991d9fa0
JT
902static int __open_device(struct dm_pool_metadata *pmd,
903 dm_thin_id dev, int create,
904 struct dm_thin_device **td)
905{
906 int r, changed = 0;
907 struct dm_thin_device *td2;
908 uint64_t key = dev;
909 struct disk_device_details details_le;
910
911 /*
1f3db25d 912 * If the device is already open, return it.
991d9fa0
JT
913 */
914 list_for_each_entry(td2, &pmd->thin_devices, list)
915 if (td2->id == dev) {
1f3db25d
MS
916 /*
917 * May not create an already-open device.
918 */
919 if (create)
920 return -EEXIST;
921
991d9fa0
JT
922 td2->open_count++;
923 *td = td2;
924 return 0;
925 }
926
927 /*
928 * Check the device exists.
929 */
930 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
931 &key, &details_le);
932 if (r) {
933 if (r != -ENODATA || !create)
934 return r;
935
1f3db25d
MS
936 /*
937 * Create new device.
938 */
991d9fa0
JT
939 changed = 1;
940 details_le.mapped_blocks = 0;
941 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
942 details_le.creation_time = cpu_to_le32(pmd->time);
943 details_le.snapshotted_time = cpu_to_le32(pmd->time);
944 }
945
946 *td = kmalloc(sizeof(**td), GFP_NOIO);
947 if (!*td)
948 return -ENOMEM;
949
950 (*td)->pmd = pmd;
951 (*td)->id = dev;
952 (*td)->open_count = 1;
953 (*td)->changed = changed;
da105ed5 954 (*td)->aborted_with_changes = false;
991d9fa0
JT
955 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
956 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
957 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
958 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
959
960 list_add(&(*td)->list, &pmd->thin_devices);
961
962 return 0;
963}
964
965static void __close_device(struct dm_thin_device *td)
966{
967 --td->open_count;
968}
969
970static int __create_thin(struct dm_pool_metadata *pmd,
971 dm_thin_id dev)
972{
973 int r;
974 dm_block_t dev_root;
975 uint64_t key = dev;
976 struct disk_device_details details_le;
977 struct dm_thin_device *td;
978 __le64 value;
979
980 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
981 &key, &details_le);
982 if (!r)
983 return -EEXIST;
984
985 /*
986 * Create an empty btree for the mappings.
987 */
988 r = dm_btree_empty(&pmd->bl_info, &dev_root);
989 if (r)
990 return r;
991
992 /*
993 * Insert it into the main mapping tree.
994 */
995 value = cpu_to_le64(dev_root);
996 __dm_bless_for_disk(&value);
997 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
998 if (r) {
999 dm_btree_del(&pmd->bl_info, dev_root);
1000 return r;
1001 }
1002
1003 r = __open_device(pmd, dev, 1, &td);
1004 if (r) {
991d9fa0
JT
1005 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1006 dm_btree_del(&pmd->bl_info, dev_root);
1007 return r;
1008 }
991d9fa0
JT
1009 __close_device(td);
1010
1011 return r;
1012}
1013
1014int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1015{
da105ed5 1016 int r = -EINVAL;
991d9fa0
JT
1017
1018 down_write(&pmd->root_lock);
da105ed5
JT
1019 if (!pmd->fail_io)
1020 r = __create_thin(pmd, dev);
991d9fa0
JT
1021 up_write(&pmd->root_lock);
1022
1023 return r;
1024}
1025
1026static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1027 struct dm_thin_device *snap,
1028 dm_thin_id origin, uint32_t time)
1029{
1030 int r;
1031 struct dm_thin_device *td;
1032
1033 r = __open_device(pmd, origin, 0, &td);
1034 if (r)
1035 return r;
1036
1037 td->changed = 1;
1038 td->snapshotted_time = time;
1039
1040 snap->mapped_blocks = td->mapped_blocks;
1041 snap->snapshotted_time = time;
1042 __close_device(td);
1043
1044 return 0;
1045}
1046
1047static int __create_snap(struct dm_pool_metadata *pmd,
1048 dm_thin_id dev, dm_thin_id origin)
1049{
1050 int r;
1051 dm_block_t origin_root;
1052 uint64_t key = origin, dev_key = dev;
1053 struct dm_thin_device *td;
1054 struct disk_device_details details_le;
1055 __le64 value;
1056
1057 /* check this device is unused */
1058 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1059 &dev_key, &details_le);
1060 if (!r)
1061 return -EEXIST;
1062
1063 /* find the mapping tree for the origin */
1064 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1065 if (r)
1066 return r;
1067 origin_root = le64_to_cpu(value);
1068
1069 /* clone the origin, an inc will do */
1070 dm_tm_inc(pmd->tm, origin_root);
1071
1072 /* insert into the main mapping tree */
1073 value = cpu_to_le64(origin_root);
1074 __dm_bless_for_disk(&value);
1075 key = dev;
1076 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1077 if (r) {
1078 dm_tm_dec(pmd->tm, origin_root);
1079 return r;
1080 }
1081
1082 pmd->time++;
1083
1084 r = __open_device(pmd, dev, 1, &td);
1085 if (r)
1086 goto bad;
1087
1088 r = __set_snapshot_details(pmd, td, origin, pmd->time);
1f3db25d
MS
1089 __close_device(td);
1090
991d9fa0
JT
1091 if (r)
1092 goto bad;
1093
991d9fa0
JT
1094 return 0;
1095
1096bad:
991d9fa0
JT
1097 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1098 dm_btree_remove(&pmd->details_info, pmd->details_root,
1099 &key, &pmd->details_root);
1100 return r;
1101}
1102
1103int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1104 dm_thin_id dev,
1105 dm_thin_id origin)
1106{
da105ed5 1107 int r = -EINVAL;
991d9fa0
JT
1108
1109 down_write(&pmd->root_lock);
da105ed5
JT
1110 if (!pmd->fail_io)
1111 r = __create_snap(pmd, dev, origin);
991d9fa0
JT
1112 up_write(&pmd->root_lock);
1113
1114 return r;
1115}
1116
1117static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1118{
1119 int r;
1120 uint64_t key = dev;
1121 struct dm_thin_device *td;
1122
1123 /* TODO: failure should mark the transaction invalid */
1124 r = __open_device(pmd, dev, 0, &td);
1125 if (r)
1126 return r;
1127
1128 if (td->open_count > 1) {
1129 __close_device(td);
1130 return -EBUSY;
1131 }
1132
1133 list_del(&td->list);
1134 kfree(td);
1135 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1136 &key, &pmd->details_root);
1137 if (r)
1138 return r;
1139
1140 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1141 if (r)
1142 return r;
1143
991d9fa0
JT
1144 return 0;
1145}
1146
1147int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1148 dm_thin_id dev)
1149{
da105ed5 1150 int r = -EINVAL;
991d9fa0
JT
1151
1152 down_write(&pmd->root_lock);
da105ed5
JT
1153 if (!pmd->fail_io)
1154 r = __delete_device(pmd, dev);
991d9fa0
JT
1155 up_write(&pmd->root_lock);
1156
1157 return r;
1158}
1159
1160int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1161 uint64_t current_id,
1162 uint64_t new_id)
1163{
da105ed5
JT
1164 int r = -EINVAL;
1165
991d9fa0 1166 down_write(&pmd->root_lock);
da105ed5
JT
1167
1168 if (pmd->fail_io)
1169 goto out;
1170
991d9fa0 1171 if (pmd->trans_id != current_id) {
991d9fa0 1172 DMERR("mismatched transaction id");
da105ed5 1173 goto out;
991d9fa0
JT
1174 }
1175
1176 pmd->trans_id = new_id;
da105ed5
JT
1177 r = 0;
1178
1179out:
991d9fa0
JT
1180 up_write(&pmd->root_lock);
1181
da105ed5 1182 return r;
991d9fa0
JT
1183}
1184
1185int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1186 uint64_t *result)
1187{
da105ed5
JT
1188 int r = -EINVAL;
1189
991d9fa0 1190 down_read(&pmd->root_lock);
da105ed5
JT
1191 if (!pmd->fail_io) {
1192 *result = pmd->trans_id;
1193 r = 0;
1194 }
991d9fa0
JT
1195 up_read(&pmd->root_lock);
1196
da105ed5 1197 return r;
991d9fa0
JT
1198}
1199
cc8394d8
JT
1200static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1201{
1202 int r, inc;
1203 struct thin_disk_superblock *disk_super;
1204 struct dm_block *copy, *sblock;
1205 dm_block_t held_root;
1206
49e99fc7
JT
1207 /*
1208 * We commit to ensure the btree roots which we increment in a
1209 * moment are up to date.
1210 */
1211 __commit_transaction(pmd);
1212
cc8394d8
JT
1213 /*
1214 * Copy the superblock.
1215 */
1216 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1217 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1218 &sb_validator, &copy, &inc);
1219 if (r)
1220 return r;
1221
1222 BUG_ON(!inc);
1223
1224 held_root = dm_block_location(copy);
1225 disk_super = dm_block_data(copy);
1226
1227 if (le64_to_cpu(disk_super->held_root)) {
1228 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1229
1230 dm_tm_dec(pmd->tm, held_root);
1231 dm_tm_unlock(pmd->tm, copy);
cc8394d8
JT
1232 return -EBUSY;
1233 }
1234
1235 /*
1236 * Wipe the spacemap since we're not publishing this.
1237 */
1238 memset(&disk_super->data_space_map_root, 0,
1239 sizeof(disk_super->data_space_map_root));
1240 memset(&disk_super->metadata_space_map_root, 0,
1241 sizeof(disk_super->metadata_space_map_root));
1242
1243 /*
1244 * Increment the data structures that need to be preserved.
1245 */
1246 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1247 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1248 dm_tm_unlock(pmd->tm, copy);
1249
1250 /*
1251 * Write the held root into the superblock.
1252 */
25971192 1253 r = superblock_lock(pmd, &sblock);
cc8394d8
JT
1254 if (r) {
1255 dm_tm_dec(pmd->tm, held_root);
cc8394d8
JT
1256 return r;
1257 }
1258
1259 disk_super = dm_block_data(sblock);
1260 disk_super->held_root = cpu_to_le64(held_root);
1261 dm_bm_unlock(sblock);
cc8394d8
JT
1262 return 0;
1263}
1264
1265int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1266{
da105ed5 1267 int r = -EINVAL;
cc8394d8
JT
1268
1269 down_write(&pmd->root_lock);
da105ed5
JT
1270 if (!pmd->fail_io)
1271 r = __reserve_metadata_snap(pmd);
cc8394d8
JT
1272 up_write(&pmd->root_lock);
1273
1274 return r;
1275}
1276
1277static int __release_metadata_snap(struct dm_pool_metadata *pmd)
991d9fa0
JT
1278{
1279 int r;
1280 struct thin_disk_superblock *disk_super;
cc8394d8
JT
1281 struct dm_block *sblock, *copy;
1282 dm_block_t held_root;
991d9fa0 1283
25971192 1284 r = superblock_lock(pmd, &sblock);
991d9fa0
JT
1285 if (r)
1286 return r;
1287
cc8394d8
JT
1288 disk_super = dm_block_data(sblock);
1289 held_root = le64_to_cpu(disk_super->held_root);
1290 disk_super->held_root = cpu_to_le64(0);
cc8394d8
JT
1291
1292 dm_bm_unlock(sblock);
1293
1294 if (!held_root) {
1295 DMWARN("No pool metadata snapshot found: nothing to release.");
1296 return -EINVAL;
1297 }
1298
1299 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
1300 if (r)
1301 return r;
1302
1303 disk_super = dm_block_data(copy);
7f518ad0
JT
1304 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
1305 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
cc8394d8
JT
1306 dm_sm_dec_block(pmd->metadata_sm, held_root);
1307
4c7da06f
MP
1308 dm_tm_unlock(pmd->tm, copy);
1309
1310 return 0;
cc8394d8
JT
1311}
1312
1313int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1314{
da105ed5 1315 int r = -EINVAL;
cc8394d8
JT
1316
1317 down_write(&pmd->root_lock);
da105ed5
JT
1318 if (!pmd->fail_io)
1319 r = __release_metadata_snap(pmd);
cc8394d8
JT
1320 up_write(&pmd->root_lock);
1321
1322 return r;
1323}
1324
1325static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1326 dm_block_t *result)
1327{
1328 int r;
1329 struct thin_disk_superblock *disk_super;
1330 struct dm_block *sblock;
1331
1332 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1333 &sb_validator, &sblock);
1334 if (r)
1335 return r;
1336
991d9fa0
JT
1337 disk_super = dm_block_data(sblock);
1338 *result = le64_to_cpu(disk_super->held_root);
1339
4c7da06f
MP
1340 dm_bm_unlock(sblock);
1341
1342 return 0;
991d9fa0
JT
1343}
1344
cc8394d8
JT
1345int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1346 dm_block_t *result)
991d9fa0 1347{
da105ed5 1348 int r = -EINVAL;
991d9fa0
JT
1349
1350 down_read(&pmd->root_lock);
da105ed5
JT
1351 if (!pmd->fail_io)
1352 r = __get_metadata_snap(pmd, result);
991d9fa0
JT
1353 up_read(&pmd->root_lock);
1354
1355 return r;
1356}
1357
1358int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1359 struct dm_thin_device **td)
1360{
da105ed5 1361 int r = -EINVAL;
991d9fa0
JT
1362
1363 down_write(&pmd->root_lock);
da105ed5
JT
1364 if (!pmd->fail_io)
1365 r = __open_device(pmd, dev, 0, td);
991d9fa0
JT
1366 up_write(&pmd->root_lock);
1367
1368 return r;
1369}
1370
1371int dm_pool_close_thin_device(struct dm_thin_device *td)
1372{
1373 down_write(&td->pmd->root_lock);
1374 __close_device(td);
1375 up_write(&td->pmd->root_lock);
1376
1377 return 0;
1378}
1379
1380dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1381{
1382 return td->id;
1383}
1384
19fa1a67
JT
1385/*
1386 * Check whether @time (of block creation) is older than @td's last snapshot.
1387 * If so then the associated block is shared with the last snapshot device.
1388 * Any block on a device created *after* the device last got snapshotted is
1389 * necessarily not shared.
1390 */
17b7d63f 1391static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
991d9fa0
JT
1392{
1393 return td->snapshotted_time > time;
1394}
1395
3d5f6733
JT
1396static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
1397 struct dm_thin_lookup_result *result)
1398{
1399 uint64_t block_time = 0;
1400 dm_block_t exception_block;
1401 uint32_t exception_time;
1402
1403 block_time = le64_to_cpu(value);
1404 unpack_block_time(block_time, &exception_block, &exception_time);
1405 result->block = exception_block;
1406 result->shared = __snapshotted_since(td, exception_time);
1407}
1408
086fbbbd
JT
1409static int __find_block(struct dm_thin_device *td, dm_block_t block,
1410 int can_issue_io, struct dm_thin_lookup_result *result)
991d9fa0 1411{
e5cfc69a 1412 int r;
991d9fa0
JT
1413 __le64 value;
1414 struct dm_pool_metadata *pmd = td->pmd;
1415 dm_block_t keys[2] = { td->id, block };
da105ed5 1416 struct dm_btree_info *info;
991d9fa0 1417
e5cfc69a
JT
1418 if (can_issue_io) {
1419 info = &pmd->info;
1420 } else
1421 info = &pmd->nb_info;
da105ed5 1422
e5cfc69a 1423 r = dm_btree_lookup(info, pmd->root, keys, &value);
3d5f6733
JT
1424 if (!r)
1425 unpack_lookup_result(td, value, result);
1426
3d5f6733
JT
1427 return r;
1428}
1429
086fbbbd
JT
1430int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1431 int can_issue_io, struct dm_thin_lookup_result *result)
3d5f6733
JT
1432{
1433 int r;
3d5f6733 1434 struct dm_pool_metadata *pmd = td->pmd;
3d5f6733
JT
1435
1436 down_read(&pmd->root_lock);
1437 if (pmd->fail_io) {
1438 up_read(&pmd->root_lock);
1439 return -EINVAL;
991d9fa0
JT
1440 }
1441
086fbbbd
JT
1442 r = __find_block(td, block, can_issue_io, result);
1443
1444 up_read(&pmd->root_lock);
1445 return r;
1446}
1447
1448static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
1449 dm_block_t *vblock,
1450 struct dm_thin_lookup_result *result)
1451{
1452 int r;
1453 __le64 value;
1454 struct dm_pool_metadata *pmd = td->pmd;
1455 dm_block_t keys[2] = { td->id, block };
1456
3d5f6733
JT
1457 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1458 if (!r)
1459 unpack_lookup_result(td, value, result);
1460
991d9fa0
JT
1461 return r;
1462}
1463
086fbbbd
JT
1464static int __find_mapped_range(struct dm_thin_device *td,
1465 dm_block_t begin, dm_block_t end,
1466 dm_block_t *thin_begin, dm_block_t *thin_end,
1467 dm_block_t *pool_begin, bool *maybe_shared)
a5d895a9
JT
1468{
1469 int r;
1470 dm_block_t pool_end;
1471 struct dm_thin_lookup_result lookup;
1472
1473 if (end < begin)
1474 return -ENODATA;
1475
086fbbbd 1476 r = __find_next_mapped_block(td, begin, &begin, &lookup);
3d5f6733
JT
1477 if (r)
1478 return r;
a5d895a9 1479
3d5f6733 1480 if (begin >= end)
a5d895a9
JT
1481 return -ENODATA;
1482
1483 *thin_begin = begin;
1484 *pool_begin = lookup.block;
1485 *maybe_shared = lookup.shared;
1486
1487 begin++;
1488 pool_end = *pool_begin + 1;
1489 while (begin != end) {
086fbbbd 1490 r = __find_block(td, begin, true, &lookup);
a5d895a9
JT
1491 if (r) {
1492 if (r == -ENODATA)
1493 break;
1494 else
1495 return r;
1496 }
1497
1498 if ((lookup.block != pool_end) ||
1499 (lookup.shared != *maybe_shared))
1500 break;
1501
1502 pool_end++;
1503 begin++;
1504 }
1505
1506 *thin_end = begin;
1507 return 0;
1508}
1509
086fbbbd
JT
1510int dm_thin_find_mapped_range(struct dm_thin_device *td,
1511 dm_block_t begin, dm_block_t end,
1512 dm_block_t *thin_begin, dm_block_t *thin_end,
1513 dm_block_t *pool_begin, bool *maybe_shared)
1514{
1515 int r = -EINVAL;
1516 struct dm_pool_metadata *pmd = td->pmd;
1517
1518 down_read(&pmd->root_lock);
1519 if (!pmd->fail_io) {
1520 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
1521 pool_begin, maybe_shared);
1522 }
1523 up_read(&pmd->root_lock);
1524
1525 return r;
1526}
1527
991d9fa0
JT
1528static int __insert(struct dm_thin_device *td, dm_block_t block,
1529 dm_block_t data_block)
1530{
1531 int r, inserted;
1532 __le64 value;
1533 struct dm_pool_metadata *pmd = td->pmd;
1534 dm_block_t keys[2] = { td->id, block };
1535
991d9fa0
JT
1536 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1537 __dm_bless_for_disk(&value);
1538
1539 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1540 &pmd->root, &inserted);
1541 if (r)
1542 return r;
1543
40db5a53
JT
1544 td->changed = 1;
1545 if (inserted)
991d9fa0 1546 td->mapped_blocks++;
991d9fa0
JT
1547
1548 return 0;
1549}
1550
1551int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1552 dm_block_t data_block)
1553{
da105ed5 1554 int r = -EINVAL;
991d9fa0
JT
1555
1556 down_write(&td->pmd->root_lock);
da105ed5
JT
1557 if (!td->pmd->fail_io)
1558 r = __insert(td, block, data_block);
991d9fa0
JT
1559 up_write(&td->pmd->root_lock);
1560
1561 return r;
1562}
1563
1564static int __remove(struct dm_thin_device *td, dm_block_t block)
1565{
1566 int r;
1567 struct dm_pool_metadata *pmd = td->pmd;
1568 dm_block_t keys[2] = { td->id, block };
1569
1570 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1571 if (r)
1572 return r;
1573
af63bcb8
JT
1574 td->mapped_blocks--;
1575 td->changed = 1;
991d9fa0
JT
1576
1577 return 0;
1578}
1579
6550f075
JT
1580static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1581{
1582 int r;
993ceab9 1583 unsigned count, total_count = 0;
6550f075
JT
1584 struct dm_pool_metadata *pmd = td->pmd;
1585 dm_block_t keys[1] = { td->id };
1586 __le64 value;
1587 dm_block_t mapping_root;
1588
1589 /*
1590 * Find the mapping tree
1591 */
1592 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
1593 if (r)
1594 return r;
1595
1596 /*
1597 * Remove from the mapping tree, taking care to inc the
1598 * ref count so it doesn't get deleted.
1599 */
1600 mapping_root = le64_to_cpu(value);
1601 dm_tm_inc(pmd->tm, mapping_root);
1602 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
1603 if (r)
1604 return r;
1605
993ceab9
JT
1606 /*
1607 * Remove leaves stops at the first unmapped entry, so we have to
1608 * loop round finding mapped ranges.
1609 */
1610 while (begin < end) {
1611 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
1612 if (r == -ENODATA)
1613 break;
1614
1615 if (r)
1616 return r;
1617
1618 if (begin >= end)
1619 break;
1620
1621 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
1622 if (r)
1623 return r;
1624
1625 total_count += count;
1626 }
6550f075 1627
993ceab9 1628 td->mapped_blocks -= total_count;
6550f075
JT
1629 td->changed = 1;
1630
1631 /*
1632 * Reinsert the mapping tree.
1633 */
1634 value = cpu_to_le64(mapping_root);
1635 __dm_bless_for_disk(&value);
1636 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
1637}
1638
991d9fa0
JT
1639int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1640{
da105ed5 1641 int r = -EINVAL;
991d9fa0
JT
1642
1643 down_write(&td->pmd->root_lock);
da105ed5
JT
1644 if (!td->pmd->fail_io)
1645 r = __remove(td, block);
991d9fa0 1646 up_write(&td->pmd->root_lock);
19fa1a67
JT
1647
1648 return r;
1649}
1650
6550f075
JT
1651int dm_thin_remove_range(struct dm_thin_device *td,
1652 dm_block_t begin, dm_block_t end)
1653{
1654 int r = -EINVAL;
1655
1656 down_write(&td->pmd->root_lock);
1657 if (!td->pmd->fail_io)
1658 r = __remove_range(td, begin, end);
1659 up_write(&td->pmd->root_lock);
1660
1661 return r;
1662}
1663
19fa1a67
JT
1664int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
1665{
1666 int r;
1667 uint32_t ref_count;
1668
1669 down_read(&pmd->root_lock);
1670 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
1671 if (!r)
1672 *result = (ref_count != 0);
1673 up_read(&pmd->root_lock);
991d9fa0
JT
1674
1675 return r;
1676}
1677
2a0fbffb
JT
1678int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1679{
1680 int r = 0;
1681
1682 down_write(&pmd->root_lock);
1683 for (; b != e; b++) {
1684 r = dm_sm_inc_block(pmd->data_sm, b);
1685 if (r)
1686 break;
1687 }
1688 up_write(&pmd->root_lock);
1689
1690 return r;
1691}
1692
1693int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
1694{
1695 int r = 0;
1696
1697 down_write(&pmd->root_lock);
1698 for (; b != e; b++) {
1699 r = dm_sm_dec_block(pmd->data_sm, b);
1700 if (r)
1701 break;
1702 }
1703 up_write(&pmd->root_lock);
1704
1705 return r;
1706}
1707
40db5a53
JT
1708bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1709{
1710 int r;
1711
1712 down_read(&td->pmd->root_lock);
1713 r = td->changed;
1714 up_read(&td->pmd->root_lock);
1715
1716 return r;
1717}
1718
4d1662a3
MS
1719bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
1720{
1721 bool r = false;
1722 struct dm_thin_device *td, *tmp;
1723
1724 down_read(&pmd->root_lock);
1725 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
1726 if (td->changed) {
1727 r = td->changed;
1728 break;
1729 }
1730 }
1731 up_read(&pmd->root_lock);
1732
1733 return r;
1734}
1735
da105ed5
JT
1736bool dm_thin_aborted_changes(struct dm_thin_device *td)
1737{
1738 bool r;
1739
1740 down_read(&td->pmd->root_lock);
1741 r = td->aborted_with_changes;
1742 up_read(&td->pmd->root_lock);
1743
1744 return r;
1745}
1746
991d9fa0
JT
1747int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1748{
da105ed5 1749 int r = -EINVAL;
991d9fa0
JT
1750
1751 down_write(&pmd->root_lock);
da105ed5
JT
1752 if (!pmd->fail_io)
1753 r = dm_sm_new_block(pmd->data_sm, result);
991d9fa0
JT
1754 up_write(&pmd->root_lock);
1755
1756 return r;
1757}
1758
1759int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1760{
da105ed5 1761 int r = -EINVAL;
991d9fa0
JT
1762
1763 down_write(&pmd->root_lock);
da105ed5
JT
1764 if (pmd->fail_io)
1765 goto out;
991d9fa0
JT
1766
1767 r = __commit_transaction(pmd);
1768 if (r <= 0)
1769 goto out;
1770
1771 /*
1772 * Open the next transaction.
1773 */
1774 r = __begin_transaction(pmd);
1775out:
1776 up_write(&pmd->root_lock);
1777 return r;
1778}
1779
da105ed5
JT
1780static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1781{
1782 struct dm_thin_device *td;
1783
1784 list_for_each_entry(td, &pmd->thin_devices, list)
1785 td->aborted_with_changes = td->changed;
1786}
1787
1788int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1789{
1790 int r = -EINVAL;
1791
1792 down_write(&pmd->root_lock);
1793 if (pmd->fail_io)
1794 goto out;
1795
1796 __set_abort_with_changes_flags(pmd);
1797 __destroy_persistent_data_objects(pmd);
1798 r = __create_persistent_data_objects(pmd, false);
1799 if (r)
1800 pmd->fail_io = true;
1801
1802out:
1803 up_write(&pmd->root_lock);
1804
1805 return r;
1806}
1807
991d9fa0
JT
1808int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1809{
da105ed5 1810 int r = -EINVAL;
991d9fa0
JT
1811
1812 down_read(&pmd->root_lock);
da105ed5
JT
1813 if (!pmd->fail_io)
1814 r = dm_sm_get_nr_free(pmd->data_sm, result);
991d9fa0
JT
1815 up_read(&pmd->root_lock);
1816
1817 return r;
1818}
1819
1820int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1821 dm_block_t *result)
1822{
da105ed5 1823 int r = -EINVAL;
991d9fa0
JT
1824
1825 down_read(&pmd->root_lock);
da105ed5
JT
1826 if (!pmd->fail_io)
1827 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
991d9fa0
JT
1828 up_read(&pmd->root_lock);
1829
1830 return r;
1831}
1832
1833int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1834 dm_block_t *result)
1835{
da105ed5 1836 int r = -EINVAL;
991d9fa0
JT
1837
1838 down_read(&pmd->root_lock);
da105ed5
JT
1839 if (!pmd->fail_io)
1840 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
991d9fa0
JT
1841 up_read(&pmd->root_lock);
1842
1843 return r;
1844}
1845
991d9fa0
JT
1846int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1847{
da105ed5 1848 int r = -EINVAL;
991d9fa0
JT
1849
1850 down_read(&pmd->root_lock);
da105ed5
JT
1851 if (!pmd->fail_io)
1852 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
991d9fa0
JT
1853 up_read(&pmd->root_lock);
1854
1855 return r;
1856}
1857
1858int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1859{
da105ed5 1860 int r = -EINVAL;
991d9fa0
JT
1861 struct dm_pool_metadata *pmd = td->pmd;
1862
1863 down_read(&pmd->root_lock);
da105ed5
JT
1864 if (!pmd->fail_io) {
1865 *result = td->mapped_blocks;
1866 r = 0;
1867 }
991d9fa0
JT
1868 up_read(&pmd->root_lock);
1869
da105ed5 1870 return r;
991d9fa0
JT
1871}
1872
1873static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1874{
1875 int r;
1876 __le64 value_le;
1877 dm_block_t thin_root;
1878 struct dm_pool_metadata *pmd = td->pmd;
1879
1880 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1881 if (r)
1882 return r;
1883
1884 thin_root = le64_to_cpu(value_le);
1885
1886 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1887}
1888
1889int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1890 dm_block_t *result)
1891{
da105ed5 1892 int r = -EINVAL;
991d9fa0
JT
1893 struct dm_pool_metadata *pmd = td->pmd;
1894
1895 down_read(&pmd->root_lock);
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1896 if (!pmd->fail_io)
1897 r = __highest_block(td, result);
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1898 up_read(&pmd->root_lock);
1899
1900 return r;
1901}
1902
b17446df 1903static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
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1904{
1905 int r;
1906 dm_block_t old_count;
1907
b17446df 1908 r = dm_sm_get_nr_blocks(sm, &old_count);
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1909 if (r)
1910 return r;
1911
1912 if (new_count == old_count)
1913 return 0;
1914
1915 if (new_count < old_count) {
b17446df 1916 DMERR("cannot reduce size of space map");
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1917 return -EINVAL;
1918 }
1919
b17446df 1920 return dm_sm_extend(sm, new_count - old_count);
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1921}
1922
1923int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1924{
da105ed5 1925 int r = -EINVAL;
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1926
1927 down_write(&pmd->root_lock);
da105ed5 1928 if (!pmd->fail_io)
b17446df 1929 r = __resize_space_map(pmd->data_sm, new_count);
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1930 up_write(&pmd->root_lock);
1931
1932 return r;
1933}
12ba58af 1934
24347e95
JT
1935int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1936{
1937 int r = -EINVAL;
1938
1939 down_write(&pmd->root_lock);
1940 if (!pmd->fail_io)
1941 r = __resize_space_map(pmd->metadata_sm, new_count);
1942 up_write(&pmd->root_lock);
1943
1944 return r;
1945}
1946
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1947void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1948{
1949 down_write(&pmd->root_lock);
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1950 dm_bm_set_read_only(pmd->bm);
1951 up_write(&pmd->root_lock);
1952}
ac8c3f3d 1953
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JT
1954void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
1955{
1956 down_write(&pmd->root_lock);
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1957 dm_bm_set_read_write(pmd->bm);
1958 up_write(&pmd->root_lock);
1959}
1960
ac8c3f3d
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1961int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
1962 dm_block_t threshold,
1963 dm_sm_threshold_fn fn,
1964 void *context)
1965{
1966 int r;
1967
1968 down_write(&pmd->root_lock);
1969 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
1970 up_write(&pmd->root_lock);
1971
1972 return r;
1973}
07f2b6e0
MS
1974
1975int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
1976{
1977 int r;
1978 struct dm_block *sblock;
1979 struct thin_disk_superblock *disk_super;
1980
1981 down_write(&pmd->root_lock);
1982 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
1983
1984 r = superblock_lock(pmd, &sblock);
1985 if (r) {
1986 DMERR("couldn't read superblock");
1987 goto out;
1988 }
1989
1990 disk_super = dm_block_data(sblock);
1991 disk_super->flags = cpu_to_le32(pmd->flags);
1992
1993 dm_bm_unlock(sblock);
1994out:
1995 up_write(&pmd->root_lock);
1996 return r;
1997}
1998
1999bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
2000{
2001 bool needs_check;
2002
2003 down_read(&pmd->root_lock);
2004 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
2005 up_read(&pmd->root_lock);
2006
2007 return needs_check;
2008}
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2009
2010void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
2011{
2eae9e44
JT
2012 down_read(&pmd->root_lock);
2013 if (!pmd->fail_io)
2014 dm_tm_issue_prefetches(pmd->tm);
2015 up_read(&pmd->root_lock);
8a01a6af 2016}