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1 /*
2 * Copyright (C) 2011-2012 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7 #include "dm-thin-metadata.h"
8 #include "persistent-data/dm-btree.h"
9 #include "persistent-data/dm-space-map.h"
10 #include "persistent-data/dm-space-map-disk.h"
11 #include "persistent-data/dm-transaction-manager.h"
12
13 #include <linux/list.h>
14 #include <linux/device-mapper.h>
15 #include <linux/workqueue.h>
16
17 /*--------------------------------------------------------------------------
18 * As far as the metadata goes, there is:
19 *
20 * - A superblock in block zero, taking up fewer than 512 bytes for
21 * atomic writes.
22 *
23 * - A space map managing the metadata blocks.
24 *
25 * - A space map managing the data blocks.
26 *
27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
28 *
29 * - A hierarchical btree, with 2 levels which effectively maps (thin
30 * dev id, virtual block) -> block_time. Block time is a 64-bit
31 * field holding the time in the low 24 bits, and block in the top 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 SECTOR_TO_BLOCK_SHIFT 3
81
82 /*
83 * 3 for btree insert +
84 * 2 for btree lookup used within space map
85 */
86 #define THIN_MAX_CONCURRENT_LOCKS 5
87
88 /* This should be plenty */
89 #define SPACE_MAP_ROOT_SIZE 128
90
91 /*
92 * Little endian on-disk superblock and device details.
93 */
94 struct 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
134 struct disk_device_details {
135 __le64 mapped_blocks;
136 __le64 transaction_id; /* When created. */
137 __le32 creation_time;
138 __le32 snapshotted_time;
139 } __packed;
140
141 struct 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;
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;
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;
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];
200 };
201
202 struct dm_thin_device {
203 struct list_head list;
204 struct dm_pool_metadata *pmd;
205 dm_thin_id id;
206
207 int open_count;
208 bool changed:1;
209 bool aborted_with_changes:1;
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
222 static 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
234 static 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
267 static 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
277 static uint64_t pack_block_time(dm_block_t b, uint32_t t)
278 {
279 return (b << 24) | t;
280 }
281
282 static 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
288 static void data_block_inc(void *context, const void *value_le)
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
300 static void data_block_dec(void *context, const void *value_le)
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
312 static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
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
326 static void subtree_inc(void *context, const void *value)
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
337 static void subtree_dec(void *context, const void *value)
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))
346 DMERR("btree delete failed");
347 }
348
349 static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
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
360 static 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
367 static 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
374 static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
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
398 dm_bm_unlock(b);
399
400 return 0;
401 }
402
403 static void __setup_btree_details(struct dm_pool_metadata *pmd)
404 {
405 pmd->info.tm = pmd->tm;
406 pmd->info.levels = 2;
407 pmd->info.value_type.context = pmd->data_sm;
408 pmd->info.value_type.size = sizeof(__le64);
409 pmd->info.value_type.inc = data_block_inc;
410 pmd->info.value_type.dec = data_block_dec;
411 pmd->info.value_type.equal = data_block_equal;
412
413 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
414 pmd->nb_info.tm = pmd->nb_tm;
415
416 pmd->tl_info.tm = pmd->tm;
417 pmd->tl_info.levels = 1;
418 pmd->tl_info.value_type.context = &pmd->bl_info;
419 pmd->tl_info.value_type.size = sizeof(__le64);
420 pmd->tl_info.value_type.inc = subtree_inc;
421 pmd->tl_info.value_type.dec = subtree_dec;
422 pmd->tl_info.value_type.equal = subtree_equal;
423
424 pmd->bl_info.tm = pmd->tm;
425 pmd->bl_info.levels = 1;
426 pmd->bl_info.value_type.context = pmd->data_sm;
427 pmd->bl_info.value_type.size = sizeof(__le64);
428 pmd->bl_info.value_type.inc = data_block_inc;
429 pmd->bl_info.value_type.dec = data_block_dec;
430 pmd->bl_info.value_type.equal = data_block_equal;
431
432 pmd->details_info.tm = pmd->tm;
433 pmd->details_info.levels = 1;
434 pmd->details_info.value_type.context = NULL;
435 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
436 pmd->details_info.value_type.inc = NULL;
437 pmd->details_info.value_type.dec = NULL;
438 pmd->details_info.value_type.equal = NULL;
439 }
440
441 static 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
461 static 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
473 static int __write_initial_superblock(struct dm_pool_metadata *pmd)
474 {
475 int r;
476 struct dm_block *sblock;
477 struct thin_disk_superblock *disk_super;
478 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
479
480 if (bdev_size > THIN_METADATA_MAX_SECTORS)
481 bdev_size = THIN_METADATA_MAX_SECTORS;
482
483 r = dm_sm_commit(pmd->data_sm);
484 if (r < 0)
485 return r;
486
487 r = dm_tm_pre_commit(pmd->tm);
488 if (r < 0)
489 return r;
490
491 r = save_sm_roots(pmd);
492 if (r < 0)
493 return r;
494
495 r = superblock_lock_zero(pmd, &sblock);
496 if (r)
497 return r;
498
499 disk_super = dm_block_data(sblock);
500 disk_super->flags = 0;
501 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
502 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
503 disk_super->version = cpu_to_le32(THIN_VERSION);
504 disk_super->time = 0;
505 disk_super->trans_id = 0;
506 disk_super->held_root = 0;
507
508 copy_sm_roots(pmd, disk_super);
509
510 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
511 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
512 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
513 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
514 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
515
516 return dm_tm_commit(pmd->tm, sblock);
517 }
518
519 static int __format_metadata(struct dm_pool_metadata *pmd)
520 {
521 int r;
522
523 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
524 &pmd->tm, &pmd->metadata_sm);
525 if (r < 0) {
526 DMERR("tm_create_with_sm failed");
527 return r;
528 }
529
530 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
531 if (IS_ERR(pmd->data_sm)) {
532 DMERR("sm_disk_create failed");
533 r = PTR_ERR(pmd->data_sm);
534 goto bad_cleanup_tm;
535 }
536
537 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
538 if (!pmd->nb_tm) {
539 DMERR("could not create non-blocking clone tm");
540 r = -ENOMEM;
541 goto bad_cleanup_data_sm;
542 }
543
544 __setup_btree_details(pmd);
545
546 r = dm_btree_empty(&pmd->info, &pmd->root);
547 if (r < 0)
548 goto bad_cleanup_nb_tm;
549
550 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
551 if (r < 0) {
552 DMERR("couldn't create devices root");
553 goto bad_cleanup_nb_tm;
554 }
555
556 r = __write_initial_superblock(pmd);
557 if (r)
558 goto bad_cleanup_nb_tm;
559
560 return 0;
561
562 bad_cleanup_nb_tm:
563 dm_tm_destroy(pmd->nb_tm);
564 bad_cleanup_data_sm:
565 dm_sm_destroy(pmd->data_sm);
566 bad_cleanup_tm:
567 dm_tm_destroy(pmd->tm);
568 dm_sm_destroy(pmd->metadata_sm);
569
570 return r;
571 }
572
573 static 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
601 static int __open_metadata(struct dm_pool_metadata *pmd)
602 {
603 int r;
604 struct dm_block *sblock;
605 struct thin_disk_superblock *disk_super;
606
607 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
608 &sb_validator, &sblock);
609 if (r < 0) {
610 DMERR("couldn't read superblock");
611 return r;
612 }
613
614 disk_super = dm_block_data(sblock);
615
616 /* 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
625 r = __check_incompat_features(disk_super, pmd);
626 if (r < 0)
627 goto bad_unlock_sblock;
628
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");
635 goto bad_unlock_sblock;
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");
642 r = PTR_ERR(pmd->data_sm);
643 goto bad_cleanup_tm;
644 }
645
646 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
647 if (!pmd->nb_tm) {
648 DMERR("could not create non-blocking clone tm");
649 r = -ENOMEM;
650 goto bad_cleanup_data_sm;
651 }
652
653 __setup_btree_details(pmd);
654 dm_bm_unlock(sblock);
655
656 return 0;
657
658 bad_cleanup_data_sm:
659 dm_sm_destroy(pmd->data_sm);
660 bad_cleanup_tm:
661 dm_tm_destroy(pmd->tm);
662 dm_sm_destroy(pmd->metadata_sm);
663 bad_unlock_sblock:
664 dm_bm_unlock(sblock);
665
666 return r;
667 }
668
669 static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
670 {
671 int r, unformatted;
672
673 r = __superblock_all_zeroes(pmd->bm, &unformatted);
674 if (r)
675 return r;
676
677 if (unformatted)
678 return format_device ? __format_metadata(pmd) : -EPERM;
679
680 return __open_metadata(pmd);
681 }
682
683 static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
684 {
685 int r;
686
687 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
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
694 r = __open_or_format_metadata(pmd, format_device);
695 if (r)
696 dm_block_manager_destroy(pmd->bm);
697
698 return r;
699 }
700
701 static 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
710 static int __begin_transaction(struct dm_pool_metadata *pmd)
711 {
712 int r;
713 struct thin_disk_superblock *disk_super;
714 struct dm_block *sblock;
715
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
733 dm_bm_unlock(sblock);
734 return 0;
735 }
736
737 static 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 }
767 }
768
769 return 0;
770 }
771
772 static int __commit_transaction(struct dm_pool_metadata *pmd)
773 {
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)
786 return r;
787
788 r = dm_sm_commit(pmd->data_sm);
789 if (r < 0)
790 return r;
791
792 r = dm_tm_pre_commit(pmd->tm);
793 if (r < 0)
794 return r;
795
796 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
797 if (r < 0)
798 return r;
799
800 r = dm_sm_root_size(pmd->data_sm, &data_len);
801 if (r < 0)
802 return r;
803
804 r = save_sm_roots(pmd);
805 if (r < 0)
806 return r;
807
808 r = superblock_lock(pmd, &sblock);
809 if (r)
810 return r;
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
819 copy_sm_roots(pmd, disk_super);
820
821 return dm_tm_commit(pmd->tm, sblock);
822 }
823
824 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
825 sector_t data_block_size,
826 bool format_device)
827 {
828 int r;
829 struct dm_pool_metadata *pmd;
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
837 init_rwsem(&pmd->root_lock);
838 pmd->time = 0;
839 INIT_LIST_HEAD(&pmd->thin_devices);
840 pmd->fail_io = false;
841 pmd->bdev = bdev;
842 pmd->data_block_size = data_block_size;
843
844 r = __create_persistent_data_objects(pmd, format_device);
845 if (r) {
846 kfree(pmd);
847 return ERR_PTR(r);
848 }
849
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);
855 }
856
857 return pmd;
858 }
859
860 int 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
883 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
884 r = __commit_transaction(pmd);
885 if (r < 0)
886 DMWARN("%s: __commit_transaction() failed, error = %d",
887 __func__, r);
888 }
889
890 if (!pmd->fail_io)
891 __destroy_persistent_data_objects(pmd);
892
893 kfree(pmd);
894 return 0;
895 }
896
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 */
902 static 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 /*
912 * If the device is already open, return it.
913 */
914 list_for_each_entry(td2, &pmd->thin_devices, list)
915 if (td2->id == dev) {
916 /*
917 * May not create an already-open device.
918 */
919 if (create)
920 return -EEXIST;
921
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
936 /*
937 * Create new device.
938 */
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;
954 (*td)->aborted_with_changes = false;
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
965 static void __close_device(struct dm_thin_device *td)
966 {
967 --td->open_count;
968 }
969
970 static 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) {
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 }
1009 __close_device(td);
1010
1011 return r;
1012 }
1013
1014 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
1015 {
1016 int r = -EINVAL;
1017
1018 down_write(&pmd->root_lock);
1019 if (!pmd->fail_io)
1020 r = __create_thin(pmd, dev);
1021 up_write(&pmd->root_lock);
1022
1023 return r;
1024 }
1025
1026 static 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
1047 static 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);
1089 __close_device(td);
1090
1091 if (r)
1092 goto bad;
1093
1094 return 0;
1095
1096 bad:
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
1103 int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1104 dm_thin_id dev,
1105 dm_thin_id origin)
1106 {
1107 int r = -EINVAL;
1108
1109 down_write(&pmd->root_lock);
1110 if (!pmd->fail_io)
1111 r = __create_snap(pmd, dev, origin);
1112 up_write(&pmd->root_lock);
1113
1114 return r;
1115 }
1116
1117 static 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
1144 return 0;
1145 }
1146
1147 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1148 dm_thin_id dev)
1149 {
1150 int r = -EINVAL;
1151
1152 down_write(&pmd->root_lock);
1153 if (!pmd->fail_io)
1154 r = __delete_device(pmd, dev);
1155 up_write(&pmd->root_lock);
1156
1157 return r;
1158 }
1159
1160 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1161 uint64_t current_id,
1162 uint64_t new_id)
1163 {
1164 int r = -EINVAL;
1165
1166 down_write(&pmd->root_lock);
1167
1168 if (pmd->fail_io)
1169 goto out;
1170
1171 if (pmd->trans_id != current_id) {
1172 DMERR("mismatched transaction id");
1173 goto out;
1174 }
1175
1176 pmd->trans_id = new_id;
1177 r = 0;
1178
1179 out:
1180 up_write(&pmd->root_lock);
1181
1182 return r;
1183 }
1184
1185 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1186 uint64_t *result)
1187 {
1188 int r = -EINVAL;
1189
1190 down_read(&pmd->root_lock);
1191 if (!pmd->fail_io) {
1192 *result = pmd->trans_id;
1193 r = 0;
1194 }
1195 up_read(&pmd->root_lock);
1196
1197 return r;
1198 }
1199
1200 static 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
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
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);
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 */
1253 r = superblock_lock(pmd, &sblock);
1254 if (r) {
1255 dm_tm_dec(pmd->tm, held_root);
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);
1262 return 0;
1263 }
1264
1265 int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1266 {
1267 int r = -EINVAL;
1268
1269 down_write(&pmd->root_lock);
1270 if (!pmd->fail_io)
1271 r = __reserve_metadata_snap(pmd);
1272 up_write(&pmd->root_lock);
1273
1274 return r;
1275 }
1276
1277 static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1278 {
1279 int r;
1280 struct thin_disk_superblock *disk_super;
1281 struct dm_block *sblock, *copy;
1282 dm_block_t held_root;
1283
1284 r = superblock_lock(pmd, &sblock);
1285 if (r)
1286 return r;
1287
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);
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);
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));
1306 dm_sm_dec_block(pmd->metadata_sm, held_root);
1307
1308 dm_tm_unlock(pmd->tm, copy);
1309
1310 return 0;
1311 }
1312
1313 int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1314 {
1315 int r = -EINVAL;
1316
1317 down_write(&pmd->root_lock);
1318 if (!pmd->fail_io)
1319 r = __release_metadata_snap(pmd);
1320 up_write(&pmd->root_lock);
1321
1322 return r;
1323 }
1324
1325 static 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
1337 disk_super = dm_block_data(sblock);
1338 *result = le64_to_cpu(disk_super->held_root);
1339
1340 dm_bm_unlock(sblock);
1341
1342 return 0;
1343 }
1344
1345 int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1346 dm_block_t *result)
1347 {
1348 int r = -EINVAL;
1349
1350 down_read(&pmd->root_lock);
1351 if (!pmd->fail_io)
1352 r = __get_metadata_snap(pmd, result);
1353 up_read(&pmd->root_lock);
1354
1355 return r;
1356 }
1357
1358 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1359 struct dm_thin_device **td)
1360 {
1361 int r = -EINVAL;
1362
1363 down_write(&pmd->root_lock);
1364 if (!pmd->fail_io)
1365 r = __open_device(pmd, dev, 0, td);
1366 up_write(&pmd->root_lock);
1367
1368 return r;
1369 }
1370
1371 int 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
1380 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1381 {
1382 return td->id;
1383 }
1384
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 */
1391 static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1392 {
1393 return td->snapshotted_time > time;
1394 }
1395
1396 static 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
1409 static int __find_block(struct dm_thin_device *td, dm_block_t block,
1410 int can_issue_io, struct dm_thin_lookup_result *result)
1411 {
1412 int r;
1413 __le64 value;
1414 struct dm_pool_metadata *pmd = td->pmd;
1415 dm_block_t keys[2] = { td->id, block };
1416 struct dm_btree_info *info;
1417
1418 if (can_issue_io) {
1419 info = &pmd->info;
1420 } else
1421 info = &pmd->nb_info;
1422
1423 r = dm_btree_lookup(info, pmd->root, keys, &value);
1424 if (!r)
1425 unpack_lookup_result(td, value, result);
1426
1427 return r;
1428 }
1429
1430 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1431 int can_issue_io, struct dm_thin_lookup_result *result)
1432 {
1433 int r;
1434 struct dm_pool_metadata *pmd = td->pmd;
1435
1436 down_read(&pmd->root_lock);
1437 if (pmd->fail_io) {
1438 up_read(&pmd->root_lock);
1439 return -EINVAL;
1440 }
1441
1442 r = __find_block(td, block, can_issue_io, result);
1443
1444 up_read(&pmd->root_lock);
1445 return r;
1446 }
1447
1448 static 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
1457 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
1458 if (!r)
1459 unpack_lookup_result(td, value, result);
1460
1461 return r;
1462 }
1463
1464 static 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)
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
1476 r = __find_next_mapped_block(td, begin, &begin, &lookup);
1477 if (r)
1478 return r;
1479
1480 if (begin >= end)
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) {
1490 r = __find_block(td, begin, true, &lookup);
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
1510 int 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
1528 static 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
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
1544 td->changed = 1;
1545 if (inserted)
1546 td->mapped_blocks++;
1547
1548 return 0;
1549 }
1550
1551 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1552 dm_block_t data_block)
1553 {
1554 int r = -EINVAL;
1555
1556 down_write(&td->pmd->root_lock);
1557 if (!td->pmd->fail_io)
1558 r = __insert(td, block, data_block);
1559 up_write(&td->pmd->root_lock);
1560
1561 return r;
1562 }
1563
1564 static 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
1574 td->mapped_blocks--;
1575 td->changed = 1;
1576
1577 return 0;
1578 }
1579
1580 static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
1581 {
1582 int r;
1583 unsigned count, total_count = 0;
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
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 }
1627
1628 td->mapped_blocks -= total_count;
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
1639 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1640 {
1641 int r = -EINVAL;
1642
1643 down_write(&td->pmd->root_lock);
1644 if (!td->pmd->fail_io)
1645 r = __remove(td, block);
1646 up_write(&td->pmd->root_lock);
1647
1648 return r;
1649 }
1650
1651 int 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
1664 int 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);
1674
1675 return r;
1676 }
1677
1678 int 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
1693 int 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
1708 bool 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
1719 bool 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
1736 bool 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
1747 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1748 {
1749 int r = -EINVAL;
1750
1751 down_write(&pmd->root_lock);
1752 if (!pmd->fail_io)
1753 r = dm_sm_new_block(pmd->data_sm, result);
1754 up_write(&pmd->root_lock);
1755
1756 return r;
1757 }
1758
1759 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1760 {
1761 int r = -EINVAL;
1762
1763 down_write(&pmd->root_lock);
1764 if (pmd->fail_io)
1765 goto out;
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);
1775 out:
1776 up_write(&pmd->root_lock);
1777 return r;
1778 }
1779
1780 static 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
1788 int 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
1802 out:
1803 up_write(&pmd->root_lock);
1804
1805 return r;
1806 }
1807
1808 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1809 {
1810 int r = -EINVAL;
1811
1812 down_read(&pmd->root_lock);
1813 if (!pmd->fail_io)
1814 r = dm_sm_get_nr_free(pmd->data_sm, result);
1815 up_read(&pmd->root_lock);
1816
1817 return r;
1818 }
1819
1820 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1821 dm_block_t *result)
1822 {
1823 int r = -EINVAL;
1824
1825 down_read(&pmd->root_lock);
1826 if (!pmd->fail_io)
1827 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1828 up_read(&pmd->root_lock);
1829
1830 return r;
1831 }
1832
1833 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1834 dm_block_t *result)
1835 {
1836 int r = -EINVAL;
1837
1838 down_read(&pmd->root_lock);
1839 if (!pmd->fail_io)
1840 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1841 up_read(&pmd->root_lock);
1842
1843 return r;
1844 }
1845
1846 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1847 {
1848 int r = -EINVAL;
1849
1850 down_read(&pmd->root_lock);
1851 if (!pmd->fail_io)
1852 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1853 up_read(&pmd->root_lock);
1854
1855 return r;
1856 }
1857
1858 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1859 {
1860 int r = -EINVAL;
1861 struct dm_pool_metadata *pmd = td->pmd;
1862
1863 down_read(&pmd->root_lock);
1864 if (!pmd->fail_io) {
1865 *result = td->mapped_blocks;
1866 r = 0;
1867 }
1868 up_read(&pmd->root_lock);
1869
1870 return r;
1871 }
1872
1873 static 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
1889 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1890 dm_block_t *result)
1891 {
1892 int r = -EINVAL;
1893 struct dm_pool_metadata *pmd = td->pmd;
1894
1895 down_read(&pmd->root_lock);
1896 if (!pmd->fail_io)
1897 r = __highest_block(td, result);
1898 up_read(&pmd->root_lock);
1899
1900 return r;
1901 }
1902
1903 static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
1904 {
1905 int r;
1906 dm_block_t old_count;
1907
1908 r = dm_sm_get_nr_blocks(sm, &old_count);
1909 if (r)
1910 return r;
1911
1912 if (new_count == old_count)
1913 return 0;
1914
1915 if (new_count < old_count) {
1916 DMERR("cannot reduce size of space map");
1917 return -EINVAL;
1918 }
1919
1920 return dm_sm_extend(sm, new_count - old_count);
1921 }
1922
1923 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1924 {
1925 int r = -EINVAL;
1926
1927 down_write(&pmd->root_lock);
1928 if (!pmd->fail_io)
1929 r = __resize_space_map(pmd->data_sm, new_count);
1930 up_write(&pmd->root_lock);
1931
1932 return r;
1933 }
1934
1935 int 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
1947 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1948 {
1949 down_write(&pmd->root_lock);
1950 dm_bm_set_read_only(pmd->bm);
1951 up_write(&pmd->root_lock);
1952 }
1953
1954 void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
1955 {
1956 down_write(&pmd->root_lock);
1957 dm_bm_set_read_write(pmd->bm);
1958 up_write(&pmd->root_lock);
1959 }
1960
1961 int 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 }
1974
1975 int 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);
1994 out:
1995 up_write(&pmd->root_lock);
1996 return r;
1997 }
1998
1999 bool 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 }
2009
2010 void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
2011 {
2012 down_read(&pmd->root_lock);
2013 if (!pmd->fail_io)
2014 dm_tm_issue_prefetches(pmd->tm);
2015 up_read(&pmd->root_lock);
2016 }