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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / md / dm-thin-metadata.c
blob43824d73366d07723e09acd3b5007e46a64a6d32
1 /*
2 * Copyright (C) 2011-2012 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7 #include "dm-thin-metadata.h"
8 #include "persistent-data/dm-btree.h"
9 #include "persistent-data/dm-space-map.h"
10 #include "persistent-data/dm-space-map-disk.h"
11 #include "persistent-data/dm-transaction-manager.h"
12
13 #include <linux/list.h>
14 #include <linux/device-mapper.h>
15 #include <linux/workqueue.h>
16
17 /*--------------------------------------------------------------------------
18 * As far as the metadata goes, there is:
19 *
20 * - A superblock in block zero, taking up fewer than 512 bytes for
21 * atomic writes.
22 *
23 * - A space map managing the metadata blocks.
24 *
25 * - A space map managing the data blocks.
26 *
27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
28 *
29 * - A hierarchical btree, with 2 levels which effectively maps (thin
30 * dev id, virtual block) -> block_time. Block time is a 64-bit
31 * field holding the time in the low 24 bits, and block in the top 48
32 * bits.
33 *
34 * BTrees consist solely of btree_nodes, that fill a block. Some are
35 * internal nodes, as such their values are a __le64 pointing to other
36 * nodes. Leaf nodes can store data of any reasonable size (ie. much
37 * smaller than the block size). The nodes consist of the header,
38 * followed by an array of keys, followed by an array of values. We have
39 * to binary search on the keys so they're all held together to help the
40 * cpu cache.
41 *
42 * Space maps have 2 btrees:
43 *
44 * - One maps a uint64_t onto a struct index_entry. Which points to a
45 * bitmap block, and has some details about how many free entries there
46 * are etc.
47 *
48 * - The bitmap blocks have a header (for the checksum). Then the rest
49 * of the block is pairs of bits. With the meaning being:
50 *
51 * 0 - ref count is 0
52 * 1 - ref count is 1
53 * 2 - ref count is 2
54 * 3 - ref count is higher than 2
55 *
56 * - If the count is higher than 2 then the ref count is entered in a
57 * second btree that directly maps the block_address to a uint32_t ref
58 * count.
59 *
60 * The space map metadata variant doesn't have a bitmaps btree. Instead
61 * it has one single blocks worth of index_entries. This avoids
62 * recursive issues with the bitmap btree needing to allocate space in
63 * order to insert. With a small data block size such as 64k the
64 * metadata support data devices that are hundreds of terrabytes.
65 *
66 * The space maps allocate space linearly from front to back. Space that
67 * is freed in a transaction is never recycled within that transaction.
68 * To try and avoid fragmenting _free_ space the allocator always goes
69 * back and fills in gaps.
70 *
71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
72 * from the block manager.
73 *--------------------------------------------------------------------------*/
74
75 #define DM_MSG_PREFIX "thin metadata"
76
77 #define THIN_SUPERBLOCK_MAGIC 27022010
78 #define THIN_SUPERBLOCK_LOCATION 0
79 #define THIN_VERSION 2
80 #define THIN_METADATA_CACHE_SIZE 64
81 #define SECTOR_TO_BLOCK_SHIFT 3
82
83 /*
84 * 3 for btree insert +
85 * 2 for btree lookup used within space map
86 */
87 #define THIN_MAX_CONCURRENT_LOCKS 5
88
89 /* This should be plenty */
90 #define SPACE_MAP_ROOT_SIZE 128
91
92 /*
93 * Little endian on-disk superblock and device details.
94 */
95 struct 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
135 struct disk_device_details {
136 __le64 mapped_blocks;
137 __le64 transaction_id; /* When created. */
138 __le32 creation_time;
139 __le32 snapshotted_time;
140 } __packed;
141
142 struct dm_pool_metadata {
143 struct hlist_node hash;
144
145 struct block_device *bdev;
146 struct dm_block_manager *bm;
147 struct dm_space_map *metadata_sm;
148 struct dm_space_map *data_sm;
149 struct dm_transaction_manager *tm;
150 struct dm_transaction_manager *nb_tm;
151
152 /*
153 * Two-level btree.
154 * First level holds thin_dev_t.
155 * Second level holds mappings.
156 */
157 struct dm_btree_info info;
158
159 /*
160 * Non-blocking version of the above.
161 */
162 struct dm_btree_info nb_info;
163
164 /*
165 * Just the top level for deleting whole devices.
166 */
167 struct dm_btree_info tl_info;
168
169 /*
170 * Just the bottom level for creating new devices.
171 */
172 struct dm_btree_info bl_info;
173
174 /*
175 * Describes the device details btree.
176 */
177 struct dm_btree_info details_info;
178
179 struct rw_semaphore root_lock;
180 uint32_t time;
181 dm_block_t root;
182 dm_block_t details_root;
183 struct list_head thin_devices;
184 uint64_t trans_id;
185 unsigned long flags;
186 sector_t data_block_size;
187
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;
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];
201 };
202
203 struct dm_thin_device {
204 struct list_head list;
205 struct dm_pool_metadata *pmd;
206 dm_thin_id id;
207
208 int open_count;
209 bool changed:1;
210 bool aborted_with_changes:1;
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
223 static 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
235 static 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
268 static 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
278 static uint64_t pack_block_time(dm_block_t b, uint32_t t)
279 {
280 return (b << 24) | t;
281 }
282
283 static 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
289 static void data_block_inc(void *context, const void *value_le)
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
301 static void data_block_dec(void *context, const void *value_le)
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
313 static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
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
327 static void subtree_inc(void *context, const void *value)
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
338 static void subtree_dec(void *context, const void *value)
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))
347 DMERR("btree delete failed");
348 }
349
350 static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
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
361 static 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
368 static 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
375 static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
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
399 dm_bm_unlock(b);
400
401 return 0;
402 }
403
404 static 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;
419 pmd->tl_info.value_type.context = &pmd->bl_info;
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
442 static 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
462 static 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
474 static 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
484 r = dm_sm_commit(pmd->data_sm);
485 if (r < 0)
486 return r;
487
488 r = save_sm_roots(pmd);
489 if (r < 0)
490 return r;
491
492 r = dm_tm_pre_commit(pmd->tm);
493 if (r < 0)
494 return r;
495
496 r = superblock_lock_zero(pmd, &sblock);
497 if (r)
498 return r;
499
500 disk_super = dm_block_data(sblock);
501 disk_super->flags = 0;
502 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
503 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
504 disk_super->version = cpu_to_le32(THIN_VERSION);
505 disk_super->time = 0;
506 disk_super->trans_id = 0;
507 disk_super->held_root = 0;
508
509 copy_sm_roots(pmd, disk_super);
510
511 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
512 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
513 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
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
517 return dm_tm_commit(pmd->tm, sblock);
518 }
519
520 static int __format_metadata(struct dm_pool_metadata *pmd)
521 {
522 int r;
523
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 }
530
531 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
532 if (IS_ERR(pmd->data_sm)) {
533 DMERR("sm_disk_create failed");
534 r = PTR_ERR(pmd->data_sm);
535 goto bad_cleanup_tm;
536 }
537
538 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
539 if (!pmd->nb_tm) {
540 DMERR("could not create non-blocking clone tm");
541 r = -ENOMEM;
542 goto bad_cleanup_data_sm;
543 }
544
545 __setup_btree_details(pmd);
546
547 r = dm_btree_empty(&pmd->info, &pmd->root);
548 if (r < 0)
549 goto bad_cleanup_nb_tm;
550
551 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
552 if (r < 0) {
553 DMERR("couldn't create devices root");
554 goto bad_cleanup_nb_tm;
555 }
556
557 r = __write_initial_superblock(pmd);
558 if (r)
559 goto bad_cleanup_nb_tm;
560
561 return 0;
562
563 bad_cleanup_nb_tm:
564 dm_tm_destroy(pmd->nb_tm);
565 bad_cleanup_data_sm:
566 dm_sm_destroy(pmd->data_sm);
567 bad_cleanup_tm:
568 dm_tm_destroy(pmd->tm);
569 dm_sm_destroy(pmd->metadata_sm);
570
571 return r;
572 }
573
574 static 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
602 static 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);
616
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
626 r = __check_incompat_features(disk_super, pmd);
627 if (r < 0)
628 goto bad_unlock_sblock;
629
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");
636 goto bad_unlock_sblock;
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");
643 r = PTR_ERR(pmd->data_sm);
644 goto bad_cleanup_tm;
645 }
646
647 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
648 if (!pmd->nb_tm) {
649 DMERR("could not create non-blocking clone tm");
650 r = -ENOMEM;
651 goto bad_cleanup_data_sm;
652 }
653
654 __setup_btree_details(pmd);
655 dm_bm_unlock(sblock);
656
657 return 0;
658
659 bad_cleanup_data_sm:
660 dm_sm_destroy(pmd->data_sm);
661 bad_cleanup_tm:
662 dm_tm_destroy(pmd->tm);
663 dm_sm_destroy(pmd->metadata_sm);
664 bad_unlock_sblock:
665 dm_bm_unlock(sblock);
666
667 return r;
668 }
669
670 static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
671 {
672 int r, unformatted;
673
674 r = __superblock_all_zeroes(pmd->bm, &unformatted);
675 if (r)
676 return r;
677
678 if (unformatted)
679 return format_device ? __format_metadata(pmd) : -EPERM;
680
681 return __open_metadata(pmd);
682 }
683
684 static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
685 {
686 int r;
687
688 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
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
696 r = __open_or_format_metadata(pmd, format_device);
697 if (r)
698 dm_block_manager_destroy(pmd->bm);
699
700 return r;
701 }
702
703 static 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
712 static int __begin_transaction(struct dm_pool_metadata *pmd)
713 {
714 int r;
715 struct thin_disk_superblock *disk_super;
716 struct dm_block *sblock;
717
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
735 dm_bm_unlock(sblock);
736 return 0;
737 }
738
739 static 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 }
769 }
770
771 return 0;
772 }
773
774 static int __commit_transaction(struct dm_pool_metadata *pmd)
775 {
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)
788 return r;
789
790 r = dm_sm_commit(pmd->data_sm);
791 if (r < 0)
792 return r;
793
794 r = dm_tm_pre_commit(pmd->tm);
795 if (r < 0)
796 return r;
797
798 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
799 if (r < 0)
800 return r;
801
802 r = dm_sm_root_size(pmd->data_sm, &data_len);
803 if (r < 0)
804 return r;
805
806 r = save_sm_roots(pmd);
807 if (r < 0)
808 return r;
809
810 r = superblock_lock(pmd, &sblock);
811 if (r)
812 return r;
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
821 copy_sm_roots(pmd, disk_super);
822
823 return dm_tm_commit(pmd->tm, sblock);
824 }
825
826 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
827 sector_t data_block_size,
828 bool format_device)
829 {
830 int r;
831 struct dm_pool_metadata *pmd;
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
839 init_rwsem(&pmd->root_lock);
840 pmd->time = 0;
841 INIT_LIST_HEAD(&pmd->thin_devices);
842 pmd->fail_io = false;
843 pmd->bdev = bdev;
844 pmd->data_block_size = data_block_size;
845
846 r = __create_persistent_data_objects(pmd, format_device);
847 if (r) {
848 kfree(pmd);
849 return ERR_PTR(r);
850 }
851
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);
857 }
858
859 return pmd;
860 }
861
862 int 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
885 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
886 r = __commit_transaction(pmd);
887 if (r < 0)
888 DMWARN("%s: __commit_transaction() failed, error = %d",
889 __func__, r);
890 }
891
892 if (!pmd->fail_io)
893 __destroy_persistent_data_objects(pmd);
894
895 kfree(pmd);
896 return 0;
897 }
898
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 */
904 static 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 /*
914 * If the device is already open, return it.
915 */
916 list_for_each_entry(td2, &pmd->thin_devices, list)
917 if (td2->id == dev) {
918 /*
919 * May not create an already-open device.
920 */
921 if (create)
922 return -EEXIST;
923
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
938 /*
939 * Create new device.
940 */
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;
956 (*td)->aborted_with_changes = false;
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
967 static void __close_device(struct dm_thin_device *td)
968 {
969 --td->open_count;
970 }
971
972 static 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) {
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 }
1011 __close_device(td);
1012
1013 return r;
1014 }
1015
1016 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1017 {
1018 int r = -EINVAL;
1019
1020 down_write(&pmd->root_lock);
1021 if (!pmd->fail_io)
1022 r = __create_thin(pmd, dev);
1023 up_write(&pmd->root_lock);
1024
1025 return r;
1026 }
1027
1028 static 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
1049 static 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);
1091 __close_device(td);
1092
1093 if (r)
1094 goto bad;
1095
1096 return 0;
1097
1098 bad:
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
1105 int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1106 dm_thin_id dev,
1107 dm_thin_id origin)
1108 {
1109 int r = -EINVAL;
1110
1111 down_write(&pmd->root_lock);
1112 if (!pmd->fail_io)
1113 r = __create_snap(pmd, dev, origin);
1114 up_write(&pmd->root_lock);
1115
1116 return r;
1117 }
1118
1119 static 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
1146 return 0;
1147 }
1148
1149 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1150 dm_thin_id dev)
1151 {
1152 int r = -EINVAL;
1153
1154 down_write(&pmd->root_lock);
1155 if (!pmd->fail_io)
1156 r = __delete_device(pmd, dev);
1157 up_write(&pmd->root_lock);
1158
1159 return r;
1160 }
1161
1162 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1163 uint64_t current_id,
1164 uint64_t new_id)
1165 {
1166 int r = -EINVAL;
1167
1168 down_write(&pmd->root_lock);
1169
1170 if (pmd->fail_io)
1171 goto out;
1172
1173 if (pmd->trans_id != current_id) {
1174 DMERR("mismatched transaction id");
1175 goto out;
1176 }
1177
1178 pmd->trans_id = new_id;
1179 r = 0;
1180
1181 out:
1182 up_write(&pmd->root_lock);
1183
1184 return r;
1185 }
1186
1187 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1188 uint64_t *result)
1189 {
1190 int r = -EINVAL;
1191
1192 down_read(&pmd->root_lock);
1193 if (!pmd->fail_io) {
1194 *result = pmd->trans_id;
1195 r = 0;
1196 }
1197 up_read(&pmd->root_lock);
1198
1199 return r;
1200 }
1201
1202 static 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
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
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);
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 */
1255 r = superblock_lock(pmd, &sblock);
1256 if (r) {
1257 dm_tm_dec(pmd->tm, held_root);
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);
1264 return 0;
1265 }
1266
1267 int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1268 {
1269 int r = -EINVAL;
1270
1271 down_write(&pmd->root_lock);
1272 if (!pmd->fail_io)
1273 r = __reserve_metadata_snap(pmd);
1274 up_write(&pmd->root_lock);
1275
1276 return r;
1277 }
1278
1279 static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1280 {
1281 int r;
1282 struct thin_disk_superblock *disk_super;
1283 struct dm_block *sblock, *copy;
1284 dm_block_t held_root;
1285
1286 r = superblock_lock(pmd, &sblock);
1287 if (r)
1288 return r;
1289
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);
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);
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));
1308 dm_sm_dec_block(pmd->metadata_sm, held_root);
1309
1310 dm_tm_unlock(pmd->tm, copy);
1311
1312 return 0;
1313 }
1314
1315 int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1316 {
1317 int r = -EINVAL;
1318
1319 down_write(&pmd->root_lock);
1320 if (!pmd->fail_io)
1321 r = __release_metadata_snap(pmd);
1322 up_write(&pmd->root_lock);
1323
1324 return r;
1325 }
1326
1327 static 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
1339 disk_super = dm_block_data(sblock);
1340 *result = le64_to_cpu(disk_super->held_root);
1341
1342 dm_bm_unlock(sblock);
1343
1344 return 0;
1345 }
1346
1347 int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1348 dm_block_t *result)
1349 {
1350 int r = -EINVAL;
1351
1352 down_read(&pmd->root_lock);
1353 if (!pmd->fail_io)
1354 r = __get_metadata_snap(pmd, result);
1355 up_read(&pmd->root_lock);
1356
1357 return r;
1358 }
1359
1360 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1361 struct dm_thin_device **td)
1362 {
1363 int r = -EINVAL;
1364
1365 down_write(&pmd->root_lock);
1366 if (!pmd->fail_io)
1367 r = __open_device(pmd, dev, 0, td);
1368 up_write(&pmd->root_lock);
1369
1370 return r;
1371 }
1372
1373 int 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
1382 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1383 {
1384 return td->id;
1385 }
1386
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 */
1393 static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1394 {
1395 return td->snapshotted_time > time;
1396 }
1397
1398 static 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
1411 static int __find_block(struct dm_thin_device *td, dm_block_t block,
1412 int can_issue_io, struct dm_thin_lookup_result *result)
1413 {
1414 int r;
1415 __le64 value;
1416 struct dm_pool_metadata *pmd = td->pmd;
1417 dm_block_t keys[2] = { td->id, block };
1418 struct dm_btree_info *info;
1419
1420 if (can_issue_io) {
1421 info = &pmd->info;
1422 } else
1423 info = &pmd->nb_info;
1424
1425 r = dm_btree_lookup(info, pmd->root, keys, &value);
1426 if (!r)
1427 unpack_lookup_result(td, value, result);
1428
1429 return r;
1430 }
1431
1432 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1433 int can_issue_io, struct dm_thin_lookup_result *result)
1434 {
1435 int r;
1436 struct dm_pool_metadata *pmd = td->pmd;
1437
1438 down_read(&pmd->root_lock);
1439 if (pmd->fail_io) {
1440 up_read(&pmd->root_lock);
1441 return -EINVAL;
1442 }
1443
1444 r = __find_block(td, block, can_issue_io, result);
1445
1446 up_read(&pmd->root_lock);
1447 return r;
1448 }
1449
1450 static 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
1459 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1460 if (!r)
1461 unpack_lookup_result(td, value, result);
1462
1463 return r;
1464 }
1465
1466 static 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)
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
1478 r = __find_next_mapped_block(td, begin, &begin, &lookup);
1479 if (r)
1480 return r;
1481
1482 if (begin >= end)
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) {
1492 r = __find_block(td, begin, true, &lookup);
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
1512 int 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
1530 static 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
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
1546 td->changed = 1;
1547 if (inserted)
1548 td->mapped_blocks++;
1549
1550 return 0;
1551 }
1552
1553 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1554 dm_block_t data_block)
1555 {
1556 int r = -EINVAL;
1557
1558 down_write(&td->pmd->root_lock);
1559 if (!td->pmd->fail_io)
1560 r = __insert(td, block, data_block);
1561 up_write(&td->pmd->root_lock);
1562
1563 return r;
1564 }
1565
1566 static 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
1576 td->mapped_blocks--;
1577 td->changed = 1;
1578
1579 return 0;
1580 }
1581
1582 static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1583 {
1584 int r;
1585 unsigned count, total_count = 0;
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
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 }
1629
1630 td->mapped_blocks -= total_count;
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
1641 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1642 {
1643 int r = -EINVAL;
1644
1645 down_write(&td->pmd->root_lock);
1646 if (!td->pmd->fail_io)
1647 r = __remove(td, block);
1648 up_write(&td->pmd->root_lock);
1649
1650 return r;
1651 }
1652
1653 int 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
1666 int 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);
1676
1677 return r;
1678 }
1679
1680 bool 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
1691 bool 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
1708 bool 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
1719 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1720 {
1721 int r = -EINVAL;
1722
1723 down_write(&pmd->root_lock);
1724 if (!pmd->fail_io)
1725 r = dm_sm_new_block(pmd->data_sm, result);
1726 up_write(&pmd->root_lock);
1727
1728 return r;
1729 }
1730
1731 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1732 {
1733 int r = -EINVAL;
1734
1735 down_write(&pmd->root_lock);
1736 if (pmd->fail_io)
1737 goto out;
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);
1747 out:
1748 up_write(&pmd->root_lock);
1749 return r;
1750 }
1751
1752 static 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
1760 int 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
1774 out:
1775 up_write(&pmd->root_lock);
1776
1777 return r;
1778 }
1779
1780 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1781 {
1782 int r = -EINVAL;
1783
1784 down_read(&pmd->root_lock);
1785 if (!pmd->fail_io)
1786 r = dm_sm_get_nr_free(pmd->data_sm, result);
1787 up_read(&pmd->root_lock);
1788
1789 return r;
1790 }
1791
1792 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1793 dm_block_t *result)
1794 {
1795 int r = -EINVAL;
1796
1797 down_read(&pmd->root_lock);
1798 if (!pmd->fail_io)
1799 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1800 up_read(&pmd->root_lock);
1801
1802 return r;
1803 }
1804
1805 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1806 dm_block_t *result)
1807 {
1808 int r = -EINVAL;
1809
1810 down_read(&pmd->root_lock);
1811 if (!pmd->fail_io)
1812 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1813 up_read(&pmd->root_lock);
1814
1815 return r;
1816 }
1817
1818 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1819 {
1820 int r = -EINVAL;
1821
1822 down_read(&pmd->root_lock);
1823 if (!pmd->fail_io)
1824 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1825 up_read(&pmd->root_lock);
1826
1827 return r;
1828 }
1829
1830 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1831 {
1832 int r = -EINVAL;
1833 struct dm_pool_metadata *pmd = td->pmd;
1834
1835 down_read(&pmd->root_lock);
1836 if (!pmd->fail_io) {
1837 *result = td->mapped_blocks;
1838 r = 0;
1839 }
1840 up_read(&pmd->root_lock);
1841
1842 return r;
1843 }
1844
1845 static 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
1861 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1862 dm_block_t *result)
1863 {
1864 int r = -EINVAL;
1865 struct dm_pool_metadata *pmd = td->pmd;
1866
1867 down_read(&pmd->root_lock);
1868 if (!pmd->fail_io)
1869 r = __highest_block(td, result);
1870 up_read(&pmd->root_lock);
1871
1872 return r;
1873 }
1874
1875 static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
1876 {
1877 int r;
1878 dm_block_t old_count;
1879
1880 r = dm_sm_get_nr_blocks(sm, &old_count);
1881 if (r)
1882 return r;
1883
1884 if (new_count == old_count)
1885 return 0;
1886
1887 if (new_count < old_count) {
1888 DMERR("cannot reduce size of space map");
1889 return -EINVAL;
1890 }
1891
1892 return dm_sm_extend(sm, new_count - old_count);
1893 }
1894
1895 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1896 {
1897 int r = -EINVAL;
1898
1899 down_write(&pmd->root_lock);
1900 if (!pmd->fail_io)
1901 r = __resize_space_map(pmd->data_sm, new_count);
1902 up_write(&pmd->root_lock);
1903
1904 return r;
1905 }
1906
1907 int 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
1919 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1920 {
1921 down_write(&pmd->root_lock);
1922 dm_bm_set_read_only(pmd->bm);
1923 up_write(&pmd->root_lock);
1924 }
1925
1926 void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
1927 {
1928 down_write(&pmd->root_lock);
1929 dm_bm_set_read_write(pmd->bm);
1930 up_write(&pmd->root_lock);
1931 }
1932
1933 int 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 }
1946
1947 int 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);
1966 out:
1967 up_write(&pmd->root_lock);
1968 return r;
1969 }
1970
1971 bool 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 }
1981
1982 void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
1983 {
1984 down_read(&pmd->root_lock);
1985 if (!pmd->fail_io)
1986 dm_tm_issue_prefetches(pmd->tm);
1987 up_read(&pmd->root_lock);
1988 }
Linux with added FPC-III support